Siriraj Medical Journal
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SMJ
Volume 74, Number 2, February 2022
By Natthakrit Anansitthikorn, et al.
By Hathaichanok Suesat, et al.
ORIGINAL ARTICLE
MONTHLY
Siriraj Medical Journal
SMJ
Volume 74, Number 2, February 2022
ORIGINAL ARTICLE
75 Knowledge of Stroke and Planned Response Among Patients Living with Diabetes Mellitus
and Hypertension in A Primary Care Unit
Thareerat Ananchaisarp, et al.
85 The Analgesic Effect of Cryotherapy on Patients Undergoing Extracorporeal Shock Wave
Lithotripsy: A Randomized Controlled Trial
Chaowat Pimratana, et al.
91 Stability and Sterility of Extemporaneously Prepared 0.01% Atropine Ophthalmic Solution
in Artificial Tears and Balanced Salt Solution
Jureeporn Sri-in, et al.
100 Psychometric Properties of The Thai Mental Health Literacy Scale in Sixth-Year Medical
Students
Gobhathai Sittironnarit, et al.
108 Two-Antibody Staining Method, A Cost-Saving Strategy for Universal Lynch Syndrome
Screening in Endometrial Cancers
Natthakrit Anansitthikorn, et al.
114 Nomogram as a Predictor for Postoperative Acute Kidney Injury in Super-Elderly Patients
Undergoing Noncardiac Surgery
Thadakorn tantisarasart, et al.
126 Detection of Postoperative Cognitive Dysfunction by Telemedicine Among Octogenarian
Patients Who Underwent Minor Elective Surgery; Prospective Cohort Study
Hathaichanok Suesat, et al.
134 The Prevalence and Risk Factors of Storage Urinary Symptoms in Symptomatic COVID-19
Patients Who were Treated in Cohort Ward and Field Hospital
Valeerat Swatesutipun, et al.
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SMJ
Volume 74, No.2: 2022 Siriraj Medical Journal
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75
Original Article
SMJ
areerat Ananchaisarp, M.D., Kanyaphim Sa-a, M.D.
Division of Family and Preventive Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, ailand.
Knowledge of Stroke and Planned Response among
Patients Living with Diabetes Mellitus and
Hypertension in a Primary Care Unit
ABSTRACT
Background: Stroke is an important worldwide public health problem. Lack of knowledge in prevention methods,
warning symptoms and planned response of acute stroke are associated with a longer prehospital time, which aect
the morbidity and mortality of patients.
Objective: e primary objective was to assess knowledge of stroke prevention methods and warning symptoms
among patients living with diabetes and/or hypertension. e secondary objectives were to dene planned responses
when suspecting acute stroke, and identify associated factors with stroke knowledge scores and planned responses.
Materials and Methods: A cross-sectional study was conducted in patients living with diabetes and/or hypertension,
who had continuous follow up at the primary care unit of Songklanagarind Hospital. e outcomes of this study
were assessed by a questionnaire, which was developed from a literature review.
Results: is study included 312 participants. Median age was 64.0 years (Q1, Q3 = 58.0, 71.0), and 59.6% were
female. Median score of knowledge of stroke prevention methods were 9, from 12 points (Q1, Q3 = 8, 10), and
warning symptoms were 7, from 10 points (Q1, Q3 = 6, 8); with 80.1% of them knowing all 3 warning symptoms,
according to the acronym FAST. Only 22.8% of participants would go to the hospital immediately, by calling
an ambulance when they experienced symptoms of a suspected acute stroke. Participants who had income had
statistically signicant higher knowledge of stroke prevention methods; while participants under 60 years of age,
who had a longer duration of diagnosed diabetes mellitus were associated with appropriate planned responses
when suspecting acute stroke.
Conclusion: Patients living with diabetes mellitus and hypertension, who are at a high risk for developing cardiovascular
diseases, still do not have enough knowledge about acute stroke and had little concern about developing a stroke;
especially the elderly and those with a short duration of having been diagnosed with diabetes mellitus.
Keywords: acute stroke, knowledge, prevention methods, warning symptoms, planned response (Siriraj Med J
2022; 74: 75-84)
Corresponding author: areerat Ananchaisarp
E mail: thareerat.a@psu.ac.th
Received 1 August 2021 Revised 19 November 2021 Accepted 24 November 2021
ORCID ID: https://orcid.org/https://orcid.org/0000-0002-3386-242X
http://dx.doi.org/10.33192/Smj.2022.10
INTRODUCTION
Stroke is an important public health problem worldwide;
because stroke is life threatening
1
and is the second
leading cause of death and disability worldwide.
2
Risk
factors of stroke are categorized as non-modiable risk
factors and modiable risk factors; such as, underlying
diabetes mellitus (DM) and hypertension (HT); which
are the highest risk factors of stroke (Odds ratio = 3.55
and 2.06, respectively).
3
Although, various studies have
shown that reducing risk factors can prevent stroke,
only 27.0-37.0% of the population recognized stroke
risk factors.
4
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license unless otherwise stated.
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76
ere are two types of stroke: ischemic and hemorrhagic
stroke. When patients develop acute stroke they should
receive appropriate treatment promptly in order to
reduce mortality rate and disability.
5,6
Public health
systems realize the importance of receiving prompt
treatment, and as such many hospitals worldwide have
developed a stroke fast tract; including Songklanagarind
Hospital. Although, the stroke fast tract can reduce the
time for diagnosis of stroke and increases the usage rate
of thrombolytic therapy in ischemic stroke
7
; only 14.9%
of acute stroke patients in ailand can arrived at the
hospital in time to receive thrombolytic therapy.
4
Lack
of knowledge of stroke risk factors, warning symptoms
and planned response when suspecting acute stroke
were found to be reasons of delayed prehospital time in
acute stroke.
8-12
Clinical practice guidelines recommend
patients who have warning symptoms of stroke should
go to the hospital immediately by calling emergency
medical services (EMS)
13
; however, a study in ailand
found that only 5.0-16.0% of stroke patient used EMS
as their transportation.
14
e National Stroke Association, American Heart
Association propagate the mnemonic abbreviation “FAST”,
which stands for facial palsy, arm drip (which means
weakness of upper and/or lower extremities), abnormal
speech and going to the hospital in time; to make people
easy to remember common warning symptoms of acute
stroke and emphasize people who have warning symptoms
of stroke should go to hospital without delay; or in time, as
per the ‘T’ in FAST.
15
Beyond the 3 most common warning
symptoms of stroke, included in the acronym FAST
16
,
there are also a number of other warning symptoms of
stroke.
17
A previous population-based study found that
63.0-75.1% of participants could not recognize any stroke
warning symptoms; however, 86.1% of them knew that
they should go to the hospital if they had stroke warning
symptoms.
4,5
Factors that related to good knowledge of stroke
risk factors, prevention methods, warning symptoms and
appropriate planned response when there is a suspicion
of acute stroke were younger age, female, married, higher
education, living in the city, being employed, sucient
income and underlying DM.
4,7,18-20
While hypertensive
patients may have more knowledge of stroke over a
normotensive population
19
, some studies found that
77.0% of hypertensive patients could not identify any
stroke risk factors or warning symptoms.
20
is study was developed with the primary objective
being to assess knowledge of stroke prevention methods
and warning symptoms among patients living with diabetes
and/or hypertension, who are in the high risk group of
stroke, as there are currently few studies concerning
this topic; especially in ailand and in this specic
group of patients. e secondary objectives were to
dene planned response when suspecting acute stroke,
and identify associated factors with stroke knowledge
scores and appropriateness of planned response when
suspecting acute stroke.
MATERIALS AND METHODS
Study design
A cross-sectional study was conducted from; 1
st
May – 31
st
August 2019, amongst patients living with
diabetes and/or hypertension who had continuous follow
up at the Primary Care Unit (PCU) of Songklanagarind
Hospital, Hat Yai, ailand; this being a tertiary care
hospital in Southern ailand.
Study sample and sampling
is study included patients living with diabetes
and/or hypertension who had continuous follow up at
the Primary Care Unit (PCU) of at least 1 year, came for
follow-up during the study period, had good consciousness
and consented to participate in our research. We excluded
patients who required emergency treatment, and whom
were already diagnosed with stroke or transient ischemic
attack. e sample size was calculated for the primary
objective, by using estimate of the mean in the population
formula; with standard deviation (S.D.) being calculated
from the pilot study (S.D. =3.3 and 4.5 for knowledge
of stroke prevention methods and warning symptoms,
respectively); and error (d) = 0.5. According to the maximum
calculated value, 312 participants were required. We
enrolled participants who were compatible with our
eligibility criteria by convenience sampling method.
Variables
e outcomes were assessed by a questionnaire,
which was divided into 3 parts: 1) knowledge of stroke,
consisting of prevention methods (yes-no questions 12
items) and warning symptoms of stroke (yes-no questions
10 items); 2) planned response when suspecting acute
stroke, assessed by an opened-end question: “If you have
symptoms suspected to be acute stroke, what is the rst
thing you will do?”; and 3) factors associated with stroke
knowledge scores and planned response, consisting of
participant characteristics, general knowledge and attitude
of stroke disease. e questions to explore knowledge of
stroke and associated factors were applied from previous
studies.
19–23
e questionnaire was veried for validity
by 3 family physicians, and calculated Item Objective
Congruence Index for each question. e results of all
Ananchaisarp et al.
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Original Article
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questions were more than 0.5; however, we adjusted
some questions according to the specialist’s suggestion.
en we conducted a pretest in thirty patients living
with diabetes mellitus and/or hypertension in another
PCU; which was close to our study setting. Test-retest
reliability was used to verify correlation coecient of stroke
knowledge scores in prevention methods and warning
symptoms; the results were 0.9 and 0.7, respectively.
Data collection
ose patients who t into our eligibility criteria
were invited to participate in our research, and written
informed consent was obtained. e participants completed
the questionnaire by themselves; except for participants
who could not read the questionnaire, in such cases the
researcher helped by interviewing.
Data management and analysis
The data were entered in Epidata (version 3.1,
Denmark), with double entry basis, and analyzed using
the R program (R Core Team 2021, Vienna, Austria).
Descriptive statistical analysis was used to report the
sociodemographic characteristics of the participants, score
and detail of answer. For variables in age of participants,
we used the denition of age ≥ 60 years old to be cut-
o point of elderly; according to United Nations and
ailand’s Elderly Act. We presented categorical data in
terms of frequencies and percentage; while continuous
data were checked for normal distribution, and median
with interquartile range (IQR) was used when normal
distribution assumption was not met. We used multiple
linear regression and multiple logistic regression to assess
associated factors with stroke knowledge scores and
appropriateness of planned response when suspecting
acute stroke. Variables were eliminated in a stepwise
model, until a nal model resulted. Finally, signicant
factors were identied, based on adjusted coecient (β)
and adjusted Odds ratio, with 95% CI. A p-value < 0.05
was considered as signicant.
Ethics statement
e study protocol was approved by the Oce of
Human Research Ethics Committee (HREC), Prince of
Songkla University (REC 63-082-9-4). All participants
signed informed consent forms aer reading the participant
information sheet.
RESULTS
e baseline characteristic of 312 participants are
shown in Table 1; two thirds of them were elderly [age
range from 30.0 to 93.0 years; median (Q1, Q3) = 64.0
years (58.0, 71.0)] and more than half of them were
female. Median duration from time of diagnosis to
having diabetes and hypertension was ten years for both
diseases.
Table 2 shows general knowledge and attitude about
stroke disease in our participants; 20.5% of them had no
prior knowledge of “stroke”, and most of them thought
that a stroke was preventable. Only 5.0% of patients
living with diabetes and/or hypertension thought that
they had a high risk of developing stroke, and about one
third of the participants believed they had no risk of
developing stroke. e participants were tested for 2 parts
of stroke knowledge, consisting of: prevention methods
and warning symptoms of stroke. Table 3 shows the details
of the answers in each question concerning knowledge
of stroke prevention methods (full score = 12 points).
e median of score (Q1, Q3) was 9 points (8, 10), and
most of them had the correct knowledge concerning a
lifestyle that could prevent stroke. However, almost half
of the participants are of the opinion that using herbal
medication can prevent stroke. Table 4 shows the answers
of each question concerning warning symptoms of stroke
(full score = 10 points). e median score (Q1, Q3) was
7 points (6, 8), and more than half of them had correct
knowledge in stroke warning symptoms; especially the 3
symptoms in the acronym FAST, by the National Stroke
Association, American Heart Association.
15
More than a
third of participants did not know that sudden and severe
unexplained headaches, sudden confusion as well as
sudden trouble in seeing may be presenting symptoms of
acute stroke. Details of action that participants undertook
when having symptoms of suspected acute stroke are
shown in Table 5. More than half of them would go to
the hospital immediately by themselves or with family
members, only 22.5% of them would go to the hospital
immediately by calling EMS, and about 10.0% of them
would not go to the hospital immediately; instead they
rst rested or used alternative medicine.
Multivariate analysis of factors associated with
stroke knowledge scores and appropriateness of planned
response when suspecting acute stroke are shown in
Table 6. Participants who thought that they had a low
chance of having a stroke, and who had income were
signicantly associated with a higher score of stroke
prevention methods when compared with participants
who thought that they had no chance of having a stroke,
and whom did not have income (β = 0.40 and 0.57, p =
0.035 and 0.04; respectively). Additionally, adult patients
and those with a longer duration of being diagnosed with
DM were signicantly associated with an appropriate
planned response when suspecting acute stroke (adjusted
OR = 2.22 and 1.10; p = 0.01 and 0.02; respectively).
Volume 74, No.2: 2022 Siriraj Medical Journal
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78
TABLE 1. Sociodemographic characteristics of participants (n=312).
Characteristics
Age (years)
< 60 106 (34.0)
≥60 206(66.0)
Gender
Male 126(40.4)
Female 186 (59.6)
Occupation
Unemployed 79(25.3)
Employed 160 (51.3)
Retirement 73(23.4)
Income
No income 46 (14.7)
Havingincomes 266(85.3)
Highest level of education
Primary education level 150 (48.1)
Secondaryeducationlevel 76(24.4)
Tertiaryeducationlevel 86(27.5)
Marital status
Single 25(8.0)
Married 271(86.9)
Divorced/widow 16 (5.1)
Smoking status
a
Never 231(74.0)
Ex-smoker 63(20.2)
Current 18 (5.8)
Subgroup of participants
DM alone 34 (10.9)
HT alone 170 (54.5)
DM with HT 108 (34.6)
DurationofdiagnosedDM(year)[median(Q1,Q3)](n=142) 10.0(4.0,15.0)
DurationofdiagnosedHT(year)[median(Q1,Q3)](n=278) 10.0(5.0,15.0)
Data are presented as n (%) unless indicated otherwise.
Abbreviations: DM : diabetes mellitus; HT : hypertension
a
Smoking status
24
;
- never = participant who has never smoked, or smoked less than 100 cigarettes in their lifetime
- ex-smoker = participant who has smoked at least 100 cigarettes in their lifetime, but quit smoking at the time of interview
- current = participant who has smoked at least 100 cigarettes in their lifetime and is currently smoking
Ananchaisarp et al.
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Original Article
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TABLE 2. General knowledge and attitude about stroke disease (n=312).
TABLE 3. Knowledge on methods to prevent stroke (n=312).
General knowledge and attitude n (%)
Knowing about stroke before participating in the research
No 64(20.5)
Yes 248(79.5)
Aware that stroke is a preventable disease
No 11 (3.5)
Yes 301 (96.5)
The chance you could have a stroke
No 91(29.2)
Low 158 (50.6)
Moderate 50 (16.0)
High 13(4.2)
Methods Correct answer
n (%)
Regular exercise at least 3-5 times/week 304 (97.4)
Well control of blood pressure, plasma glucose and serum lipid 303 (97.1)
Knowingriskfactorsofstrokeandpreventingthem 300(96.2)
Smokingcessation 282(90.4)
Weightreductioninoverweightorobesepatients 281(90.1)
Decreaseconsumptionofsaltyfoods 265(84.9)
Increaseconsumptionofunsweetvegetablesandfruits 261(83.7)
Decreaseconsumptionofsweetenedbeverages 255(81.7)
Decreaseamountofalcoholdrinkinginalcoholicconsumers 246(78.8)
Using herbal medication
a
179 (57.4)
Be careful of head trauma
a
90(28.8)
Drinking pure water
a
58 (18.6)
a
lifestyles that cannot prevent stroke.
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80
TABLE 4. Knowledge of the warning symptoms of stroke (n=312).
Question Correct answer
n (%)
Sudden numbness of unilateral face, arm or leg
a
289(92.6)
Sudden weakness of unilateral face, arm or leg
a
287(92.0)
Suddentroubleinwalking/dizziness,lossofbalanceorcoordination 280(89.7)
Sudden trouble in speaking
a
279(89.4)
Sudden,severeheadachewithunknowncause 231(74.0)
Sudden muscle strain of arm or leg
b
195(62.5)
Sudden chest pain
b
190 (60.9)
Sudden confusion or misunderstanding 189 (60.6)
Sudden trouble in seeing (one or both eyes) 186 (59.6)
Sudden numbness or weakness of bilateral face, arm or leg
b
53 (17.0)
a
3 symptoms in the acronym FAST, by the National Stroke Association, American Heart Association
15
b
symptoms that are not warning symptoms of stroke
TABLE 5. Planned response when suspecting acute stroke.
Planned response n (%)
Gotohospitalimmediatelybythemselvesorfamilymembers 210(67.3)
Go to hospital immediately by calling emergency medical services
a
71(22.8)
Restathome 20(6.4)
Usingalternativemedicine 7(2.2)
Go to hospital next day 4 (1.3)
a
appropriated planned response when suspecting acute stroke
Ananchaisarp et al.
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TABLE 6. Factors associated with stroke knowledge scores and appropriateness of planned response when suspecting
acute stroke.
Stroke knowledge score Appropriate planned
Prevention methods
a
Warning symptoms
a
response when
suspecting acute stroke
by calling EMS
b
β(95%CI) p-value β(95%CI) p-value adjustedOR p-value
(95%CI)
General knowledge and attitude of stroke disease
Knowledge of stroke before
participating in the research
No Ref. Ref. Ref.
Yes 0.36(-0.04,0.76) 0.076 0.29(-0.14,0.73) 0.189 1.57(0.75,3.31) 0.235
Aware that stroke is a
preventable disease
No Ref. Ref. Ref.
Yes -0.09(-0.94,0.77) 0.845 -0.21(-1.14,0.73) 0.664 1.03(0.20,5.23) 0.970
The chance you
could have a stroke
No chance Ref. Ref. Ref.
lowchance 0.40(0.03,0.77) 0.035* 0.19(-0.21,0.59) 0.359 0.7(0.36,1.35) 0.289
Mediumchance 0.46(-0.03,0.96) 0.068 -0.17(-0.71,0.38) 0.543 0.550.22,1.38) 0.202
Highchance 0.55(-0.3,1.39) 0.206 0.32(-0.61,1.25) 0.497 0.840.21,3.36) 0.806
Sociodemographic characteristics of participant
Age (years)
≥60 Ref. Ref. Ref.
<60 0.13(-0.24,0.50) 0.493 0.31(-0.09,0.72) 0.127 2.221.18,4.17) 0.014*
Occupation
Unemployed Ref. Ref. Ref.
Employed -0.30(-0.77,0.17)0.205 0.10(-0.41,0.61) 0.691 2.310.87,6.18) 0.095
Retirement -0.06(-0.58,0.47) 0.831 0.26(-0.31,0.83) 0.369 2.400.82,7.04) 0.111
Income
No income Ref. Ref. Ref.
Havingincomes 0.57(0.02,1.12) 0.041* 0.40(-0.19,1.00)0.184 0.920.29,2.93) 0.888
Marital status
Single Ref. Ref. Ref.
Married 0.15(-0.74,0.45) 0.626 0.15(-0.50,0.80)0.647 0.440.17,1.12) 0.085
Divorced/widow -0.06(-0.97,0.85) 0.897 0.03(-0.97,1.02) 0.958 0.200.03,1.22) 0.081
Subgroup of participants
DM alone Ref. Ref. Ref.
HTalone 0.31(-0.41,1.03) 0.401 0.08(-0.71,0.87) 0.84 3.32(0.89,12.41) 0.074
DMwithHT 0.02(-0.61,0.65) 0.956 0.10(-0.59,0.80)0.768 0.76(0.24,2.40)0.645
DurationofdiagnosedDM 0.04(0,0.08) 0.076 0.02(-0.02,0.07) 0.324 1.10(1.01,1.19)0.021*
(years)
DurationofdiagnosedHT -0.02(-0.05,0.01) 0.138 0.01(-0.02,0.04) 0.475 0.96(0.91,1.02) 0.173
(years)
Abbreviations: EMS : emergency medical services; DM : diabetes mellitus; HT : hypertension
* statistical signicant,
a
multiple linear regression,
b
multiple binary logistic regression
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DISCUSSION
Most patients living with diabetes and/or hypertension,
which are a high risk group for cardiovascular disease
(CVD), could identify more than half of the stroke
prevention methods and warning symptoms; especially
in the income group. However, they still did not show
enough awareness with regards to their attitude of
concern in having a stroke. Additionally, they had an
inappropriate planned response when suspecting acute
stroke; especially the elderly and those with a short
duration of being diagnosed with DM.
Our study was conducted in patients living with
diabetes and/or hypertension, and most of our participants
were elderly. is is in contrast with previous studies
25–27
,
in which they were population-based survey’s; therefore,
reporting on younger aged participants. Women outweighed
the proportion of men in this study, which is the same
as in the previous studies.
18,28
Almost half of the study
participants graduated to the level of primary school; this
is close to a previous study that reported their participants
were of a low education level.
25
Most of the participants claimed that they knew
of the disease, namely “stroke”, before participating in
our research, similar to a previous study in hypertensive
patients
29
; and knew that a stroke is preventable. However,
we were surprised that our participants, who were in
a high risk group for CVD, had little awareness about
developing a stroke; this result was lower than that observed
amongst hypertensive patients in Pakistan.
29
It may be
due to our participants having a higher proportion of
elder patients, and lower education levels.
Most of our study participants had appropriate
knowledge with regards to the lifestyle measures to adopt
for stroke prevention. is nding corresponds with a
previous study.
30
is could be due to ailand having
emphasized the prevention of CVD for many years; such
as, the campaign in reduction of CVD risk via various
advertising media. However, more than half of our
participants misunderstood that herbal medication can
help to prevent stroke; it may be due to herbal usage being
common in ailand; including among the elderly who
were the majority of participants in our research.
31
Use of
herbal medication may make people feel self-reliant
30
; so
it is common in patients with chronic diseases.
32,33
With
regards to knowledge of stroke warning symptoms; most
of the participants had the correct knowledge concerning
symptoms that may be a presentation of acute stroke. e
results are in accordance with previous studies
12,18,27–29,34,35
,
and may be due to three out of four of them being an
element in the acronym FAST, by the National Stroke
Association, American Heart Association.
15
Additionally,
this is well known worldwide in medical advertising
for mnemonics in acute stroke symptom detection and
early management by immediately going to the hospital.
“FAST” is one of the more successful public campaigns
in promoting knowledge of common stroke warning
symptoms; as we found that most of our participants
knew all 3 symptoms in “FAST”, similar to a previous
study.
16
However FAST still has aws, in that is does not
include the less common stroke warning symptoms; as
nearly half of our participants did not know that sudden
trouble in seeing can be a warning symptom of stroke;
this was similar to previous studies.
18,20,30,36
Although,
the ‘T’ in FAST makes mention that when a patient
suspects an acute stroke they should go to the hospital
immediately, it does not mention this should be done
via EMS, according to guideline recommendations.
13
e most common planned response when acute stroke
was suspected, was to go to the hospital immediately
by themselves, or with family members; while only a
quarter of them have an appropriate planned response
by calling EMS; this is in line with a previous study.
19
Previous studies have shown that most people believed
in the benet of EMS; however, the low rate of EMS
usage may be caused from a concern in the diculty
in its process and longer ambulance waiting times.
37,38
Alternative medicine was still a choice of planned response
when suspecting acute stroke, as was the case in previous
studies.
12,19,34
is may be due to ai traditions and faith
in alternative medicines.
is study shows that participants who have income
had a statistically signicant association with increasing of
scores of stroke prevention methods; which is the same as
a previous study.
28
However, the increasing score of 0.57
points may not have any clinical benet. Adult participants
and those with a prolonged diagnosed of DM have an
appropriate planned response when having symptoms
suspected of being an acute stroke when compared with
elderly patients, and those with a shorter diagnoses of
DM; these results correspond with previous studies.
21,39
It may be due to cognitive impairment problems in the
elderly, resulting in not retaining knowledge from their
physicians or public advertising, or that they cannot call
EMS by themselves.
38
For patients with longer diagnoses
of DM, it may increase the patient’s awareness and chance
of receiving knowledge over time.
The strengths of this study consist of: firstly,
our research is one of the few studies that evaluated
knowledge of stroke in a high risk population. Secondly,
we assessed participant’s awareness of the chance of
developing a stroke, which was a topic of little interest
in previous studies. irdly, we asked for information
Ananchaisarp et al.
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83
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on planned responses when suspecting acute stroke;
instead of assessing knowledge in early management.
is was because knowledge is only just one factor that
aects behavior, and dierent contexts of each person
inuences action; such as, ease of accessibility to a nearby
hospital or ability to call EMS. In addition, this study is
one of the few study’s that explored planned responses
by an opened-end question, instead of multiple-choice
questions
12,19,34
; in order to decrease a chance of bias from
choosing the ‘good answers’ from choices. However,
there were some limitations. Firstly, we did not explore
the reason of planned response answers, for which the
results could be used for developing a method to the
solution of problems. For example; if their inappropriate
planned response came from a lack of knowledge, the
proper intervention would be education on the benets
of EMS usage. Secondly, this study was conducted in
a primary care unit of a tertiary care hospital, so the
results cannot be generalized to other hospital settings.
Lastly, the sample size was calculated for the primary
objective, so the number of the sample size may not be
large enough to show signicance in factors associated with
stroke knowledge scores, and appropriateness of planned
response. For future research, we suggest extending this
to other health care settings, increasing the sample size
for increasing statistical power of results, and adding
another helpful topic for solving some problems directly;
such as, reason of planned response as well as ability and
barrier in using EMS.
CONCLUSION
Patients living with diabetes and/or hypertension still
do not have enough knowledge of stroke. Additionally, they
have a less than acceptable level of awareness in concerns
to the risks of developing a stroke. e participants in
this study had an inappropriate planned response when
suspecting acute stroke. FAST is a successful public
campaign for promoting knowledge of the most common
warning symptoms of stroke.
ACKNOWLEDGEMENTS
We greatly appreciate the assistance of Pitchayanont
Ngamchaliew, Supakorn Sripaew, and Rattanaporn
Chootong for creating the Item Objective Congruence
index for our data collection form. We also thank Kittisakdi
Choomalee for the data analysis, and the International
Aairs Department for their assistance in editing the
English of this paper.
Conict of interest statement: none
Funding sources: none
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Chaowat Pimratana, M.D.*, Kornkanok Hengsawat, M.D.**
*Department of Surgery, **Department of Anesthesiology, Buri Ram Hospital, Buri Ram 31000, ailand.
The Analgesic Effect of Cryotherapy on Patients
Undergoing Extracorporeal Shock Wave Lithotripsy:
A Randomized Controlled Trial
ABSTRACT
Objective: To compare the degree of pain between cryotherapy and standard preoperative care in the treatment of
urolithiasis with extracorporeal shock wave lithotripsy (ESWL).
Materials and Methods: A total of 180 ESWL patients were randomly assigned to experience the standard
preoperative method, or additional cryotherapy (ice pack application on the ESWL site) for 10 minutes before
ESWL. e primary outcome was the maximum dierence of pain intensity score from baseline during ESWL
and the secondary outcomes, which were analgesic consumption, pulse rate, adverse events, stone free rate, and
complications that were gathered and analyzed.
Results: e maximum change in pain intensity score from baseline during ESWL in the cryotherapy group was
signicantly lower than in the control group (VAS score 4.0±1.9 vs. 5.2±2.7, p=0.002). e cryotherapy group showed
signicantly less total fentanyl consumption than the control group (85.3±22.0 mcg vs. 93.6±25.6, p=0.021). We
found no signicant dierence in stone free rate, adverse events or complications in either group.
Conclusion: Preoperative cryotherapy using ice packs for 10 minutes can provide an eective analgesic for ESWL.
Adequate pain control with cryotherapy should be an option of pain management during ESWL.
Keywords: Cryotherapy; ESWL; pain; urolithiasis (Siriraj Med J 2022; 74: 85-90)
Corresponding author: Chaowat Pimratana
E-mail: pchaowat@gmail.com
Received 20 May 2021 Revised 10 November 2021 Accepted 16 November 2021
ORCID ID: http://orcid.org/0000-0003-3754-774X
http://dx.doi.org/10.33192/Smj.2022.11
INTRODUCTION
Extracorporeal shock wave lithotripsy (ESWL)
has been a less-invasive option for the treatment of the
majority of patients with urolithiasis since 1980.
1
e
advancement of the new-generation lithotripter machines
has made ESWL more eective with minimal morbidity,
making it possible to perform ESWL without the need for
general or spinal anesthesia.
2
However, this procedure
can be painful because the continuous shock waves act
on the cutaneous supercial skin nociceptors and visceral
nociceptors, such as the renal capsule, peritoneal, and
musculoskeletal pain receptors.
3
Adequate pain control is
an important role in achieving successful ESWL treatment.
Opioid and sedative drugs are common analgesics for
ESWL, but certain amounts of opioids may cause nausea,
vomiting, and delayed recovery of patients.
4
Cryotherapy involves cold applications, which
have eects on both the local site around the treatment
area and at the level of the spinal cord via neurologic
and vascular mechanisms.
5
It is hypothesized that cold
applications can control pain by increasing the pain
threshold and tolerance by reducing nerve conduction
velocity, as described by the gate control theory, whereby
pain is transmitted to the dorsal horn of the spinal cord
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86
via C-bers and Aß bers; C-bers release substance P,
which opens the gate and Aß bers close the gate. Cold
applications activate the Aß bers, thereby stopping the
transmission of pain stimuli.
6,7
Many studies have been
published in regard to cryotherapy for pain reduction,
for example with knee operations, thoracic operations,
gynecologic operations, and abdominal operations.
8–11
However, no previous study has reported the analgesic
eect of cryotherapy on ESWL.
e aim of this study was to evaluate the eectiveness
of cryotherapy regarding pain control during ESWL for
urolithiasis treatment.
MATERIALS AND METHODS
is randomized controlled trial was conducted at
Buri Ram Provincial Hospital, Buri Ram, ailand. e
protocol of this research was reviewed and approved
by the ethical review board of Buri Ram Hospital (BR
0032.102.1/46) and registered in the ai Clinical Trials
Registry (TCTR20201226002). Patients with indication
for ESWL treatment were randomly assigned into two
groups. Patients in the rst group were given ice pack
compression at the skin on the ESWL site while patients
in the second group were given standard preoperative
ESWL. Between October 2020 and March 2021, kidney and
ureteric stone patients scheduled for ESWL aged 18 to 80
years with the American Society of Anesthesiologists (ASA)
physical status of I, II or III were eligible for the study.
is study excluded patients with a history of allergies to
the drugs that were used for the ESWL treatment, patients
with psychological disorders, neurological disorders,
dermatologic disorders (inammation or eczema within
the eld of cold therapy), and patients that were unable
to comprehend or use the visual analog scale (VAS).
Aer obtaining the informed written consent, the
patients that met the criteria were enrolled and divided
into two groups using computer-generated random
numbers and opaque sealed envelopes. e patients in
group I received cryotherapy; ice pack compression before
ESWL. e ice pack was kept at -10°C in a thin cloth bag
ready for future use. e ice pack was then placed on
the skin at the site of the ESWL for 10 minutes before
beginning the procedure. Control group II received standard
preoperative care. Both groups received premedication-1000
mg paracetamol and 5 mg diazepam-orally 30 minutes
before the ESWL. Initial intravenous fentanyl 1 mcg/kg
began ve minutes before the beginning of the ESWL
for every patient from both groups and a supplementary
dose of fentanyl 20 mcg intravenously was given to
patients whose pain score was greater than 4 or whose
pain tolerance was low. All patients underwent ESWL
using a Dornier Delta III Lithotripter machine in a fully
integrated operating room, and the procedure was carried
out using a similar protocol. An anesthetic nurse, who
was not involved in the study, recorded the patients’
perioperative anesthetic parameters every ve minutes.
ese parameters included blood pressure, pulse rate,
respiratory rate, oxygen saturation, sedative score, pain
score, and nausea/vomiting. e pain scores were placed
on an 11-point visual analog scale (VAS) and ranged from
0 to 10, with 0 representing no pain and 10 representing
the worst pain.
e primary outcome was the maximum of changes
in the pain intensity score from baseline during the ESWL,
using the VAS score. e secondary outcomes were total
fentanyl consumption, pulse rate, perioperative nausea/
vomiting, stone free rate at one month aer ESWL, and
any adverse events or complications.
Statistical analysis
A preliminary study containing 40 patients (20 per
group) was conducted. e preliminary study reported
the VAS score at 4.9±2.1 in the control group and
3.8±2.1 in the experimental group. e mean scores
from the preliminary study were used to calculate an
appropriate sample size for the main study. e sample
size calculation for the two independent mean tests using
a power 90% and a signicance level of 0.05 revealed a
minimum sample size of 81 participants in each group.
We added 10% of the subjects in order to accommodate
the projected dropout rate. Continuous variables were
expressed as mean ± standard deviation (SD) or median
(interquartile range, IQR) and were analyzed between
the two groups by using a t-test or the Mann-Whitney U
test. e categorical data were expressed as number and
percentage and were compared using a chi-squared test
or Fisher’s exact probability test. Statistical signicance
was set at p-value <0.05.
RESULTS
One hundred and eighty-two ESWL cases were
enrolled in the study and control groups. Two patients in
our study were excluded. Each group was composed of 90
cases (Fig 1). ere was no dierence in the demographic
data for either group, including age, sex, body mass
index (BMI), ASA physical status, stone location, time
of ESWL, lateralization, or stone size (Table 1). Intra-
operative parameters, base line pain score, pulse rate,
and initial fentanyl doses were not statistically dierent
between the two groups. e maximum of change in the
pain intensity score from baseline during the ESWL in
the cryotherapy group was signicantly lower than in the
Pimratana et al.
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Original Article
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Fig 1. Consort diagram demonstrating the ow of participants through each stage of the randomized trial.
TABLE 1. Knowledge of the warning symptoms of stroke (n=312).
Cryotherapy group Control group p-value
(n=90) (n=90)
Gender
Malen(%) 56(62.2) 56(62.2) 1.00
Age,yearmean±SD 55.5±11.6 55.9±11.0 0.812
BMI, kg/m
2
mean±SD 24.3±3.9 24.4±4.8 0.862
ASA n (%) 0.875
1 29(32.2) 31(34.4)
2 50(55.6) 50(55.6)
3 11(12.2) 9(10.0)
Stone location n (%) 0.414
Renal calculi 61 (67.8) 66 (73.3)
Uretericcalculi 29(32.2) 24(26.7)
Stone lateralization n (%)
Right side 49 (54.4) 45 (50.0) 0.551
Time of ESWL n (%)
Firsttime 32(35.6) 33(36.7) 0.877
More than 1 time 58 (64.4) 57 (63.3)
Stone size, mm median (IQR) 10.0 (10.0,15.0) 10.0 (9.5,15.0) 0.450
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control group (VAS score 4.0±1.9 vs. 5.2±2.7, p=0.002).
e cryotherapy group showed signicantly lower total
fentanyl consumption than the control group (85.3±22.0
mcg vs. 93.6±25.6 mcg, p=0.021). e stone free rate at
one month aer procedure was not dierence between
both groups (58.8% in the cryotherapy group vs. 62.2%
in the control group. We found no signicant dierence
in terms of adverse events regarding nausea/vomiting
and bradycardia in either group (Table 2).
DISCUSSION
e introduction of ESWL has been revolutionary
for the treatment of urolithiasis since 1980
1
, and new-
generation lithotripter machines have made ESWL more
eective with less morbidity, less pain, shorter recovery
time, and shorter hospital stays.
2
Nevertheless, the most
common complaint is pain and discomfort during the
treatment.
3
e pain experienced during ESWL is due
to the continuous shock waves acting on its targets,
whether from cutaneous tissue or deeper aerent nerves.
3
An adequate analgesia is mandatory for maintaining
patient comfort and improving treatment outcomes
12
,
but sometimes the patients discharge from the hospital
is delayed because of persistent sedation, and nausea and
vomiting due to the anesthetic medication administered,
so non-pharmacological methods may attract some
attention.
13
Cryotherapy for pain relief has been used
for many years, based on the gate control theory; cold
application can inhibit cutaneous input to the spinal
cord and reset the pain threshold in the central nervous
system.
6,7,9
By this means, cryotherapy is able to block
pain sensation from urinary calculi, whether its origin is
from the skin or from the deeper structures. However,
the major concern about cryotherapy is the decline in
the patient’s body core temperature and the local eects
on the areas exposed to cryotherapy. e decline in the
patient’s body temperature has harmful physiological
eects, such as Raynaud’s phenomenon, while exposure
to extreme cold can cause cold urticaria and frostbite
of the skin.
14,15
e study by Palmieri et al. showed that
TABLE 2. Outcomes
Cryotherapy group Control group p-value
(n=90) (n=90)
VAS score
At baseline median (IQR) 0.0 (0.0,0.0) 0.0 (0.0,0.0) 0.946
MaximumVASduringESWLmean±SD 4.3±1.7 5.5±2.6 <0.001*
ChangeofmaximumVASfrombaselinemean±SD 4.0±1.9 5.2±2.7 0.002*
Pulse rate mean±SD
At baseline 63.3±9.4 65.7±11.9 0.135
At15minutes 63.2±9.4 65.5±11.6 0.144
At30minutes 61.2±10.7 63.5±11.4 0.170
Initialfentanyldose(mcg)mean±SD 69.9±19.4 74.3±20.3 0.140
Totalfentanylconsumption(mcg)mean±SD 85.3±22.0 93.6±25.6 0.021*
Nauseaandvomitingn(%) 2(2.2) 2(2.2) 1.00
Bradycardian(%) 11(12.2) 9(10.0) 0.635
Skin complication (necrosis or frostbite) n (%) 0 (0) 0 (0) NA**
Stonefreerate(%) 58.8 62.2 0.760
* p-value <0.05
** NA = not applicable
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Original Article
SMJ
a cold application at the skin site for 10-20 minutes did
not decline the body core temperature.
16
ienpont
et al. demonstrated that continuous cryotherapy of
not more than 20 minutes did not cause frostbite on
the skin ap aer knee arthroplasty.
15
Further, Natalia
et al. demonstrated that a cryotherapy application of not
more than 20 minutes was safe and not uncomfortable
for any participants.
17
In this study, our protocol applied
10-minute cryotherapy and close monitoring for any
adverse event from cryotherapy during the procedure.
Many studies have used cryotherapy to decrease
pain in musculoskeletal surgery, gynecologic surgery,
cardiothoracic surgery, and abdominal surgery. e
overall results revealed benecial outcomes in terms of
pain reduction and pain management.
8–11
e present
study is the rst to emphasize the eects of cryotherapy
or cold application in ESWL treatment. In addition, this
study used the change of maximum VAS score from
baseline for the primary outcome instead of the patient’s
stated VAS score aer he or she had his/her operation.
Traditionally the VAS score is clinically meaningful from
the patient’s perspective and clinical decisions are made
based on such. However, the VAS mean scores cannot
capture the complete pain experience because pain is
both subjective and multidimensional.
18
us this study
used the change of maximum VAS score from baseline
for the primary outcome, which oers an alternative
measurement of the analgesic eect during the actual
procedure for the main outcome of our study. We found
that the pain intensity score in the cryotherapy group
was signicantly lower than in the control group (VAS
score 4.0±1.9 vs. 5.2±2.7, p=0.002).
Regarding the objective parameter, we used total
fentanyl consumption for the secondary outcome. e
cryotherapy group showed signicantly lower total fentanyl
consumption than the control group (85.3±22.0 mcg vs.
93.6±25.6 mcg, p=0.021).
In our study, bradycardia was a common side eect,
which may have been caused by both opioid usage and
cryotherapy; nevertheless, the pulse rate and bradycardia
events did not dier between the two groups (12.2% in
the cryotherapy group vs. 10.0% in the control group,
p=0.635), as the incidence was likely to be a minor adverse
eect of opioids rather than the eect of cryotherapy.
13
e emetic eect of opioids has been documented; in
our study, there was no signicant dierence in nausea
or vomiting between both groups (2% in the cryotherapy
group vs. 2% in the control group, p=1.000). Local skin
complications from cryotherapy were not present in our
study. Taking into consideration the signicant benet
of pain management from cryotherapy during ESWL, we
believe that cryotherapy is a safe, inexpensive, practical,
and eective adjuvant pain relief method.
ere were some limitations in this study. First,
we could not blind the cold application between the
cryotherapy group and the control group. Secondly, the
VAS score for pain was subjective and multidimensional.
Even though this study used the change of maximum VAS
score from baseline as an alternative measurement, this
measurement is prone to variation regarding the patient’s
pain tolerance level. In our study the stone free rate was
not signicant dierence between both groups. us,
future studies should consider using a more objective
measurement regarding outcome evaluation such as the
success rate of the stone treatment.
3,12,19,20
CONCLUSIONS
In this study we demonstrated that preoperative
cryotherapy using an ice pack for 10 minutes can provide
an eective analgesic for ESWL treatment. Adequate
pain control with cryotherapy should be an option of
pain management during ESWL.
REFERENCES
1. Chaussy C, Brendel W, Schmiedt E. Extracorporeally induced
destruction of kidney stones by shock waves. Lancet. 1980 Dec
13;2(8207):1265–8.
2. Gupta NP, Kumar A. Analgesia for pain control during
extracorporeal shock wave lithotripsy: Current status. Indian
J Urol. 2008 Apr;24(2):155–8.
3. Huang Y, Chai S, Wang D, Li W, Zhang X. Ecacy of Eutectic
Mixture of Local Anesthetics on Pain Control During Extracorporeal
Shock Wave Lithotripsy: A Systematic Review and Meta-
Analysis. Med Sci Monit. 2020 May 13;26:e921063-1-e921063-9.
4. Berwin JT, El-Husseiny T, Papatsoris AG, Hajdinjak T, Masood
J, Buchholz N. Pain in extracorporeal shock wave lithotripsy.
Urol Res. 2009 Apr;37(2):51–3.
5. Nadler SF, Weingand K, Kruse RJ. e physiologic basis and
clinical applications of cryotherapy and thermotherapy for
the pain practitioner. Pain Physician. 2004 Jul;7(3):395–9.
6. Mendell LM. Constructing and deconstructing the gate theory
of pain. Pain. 2014 Feb;155(2):210–6.
7. Ropero Peláez FJ, Taniguchi S. The Gate Theory of Pain
Revisited: Modeling Dierent Pain Conditions with a Parsimonious
Neurocomputational Model. Neural Plast. 2016;2016:4131395.
8. Tedesco D, Gori D, Desai KR, Asch S, Carroll IR, Curtin C, et al.
Drug-Free Interventions to Reduce Pain or Opioid Consumption
After Total Knee Arthroplasty: A Systematic Review and
Meta-analysis. JAMA Surg. 2017 Oct 18;152(10):e172872.
9. Gorji HM, Nesami BM, Ayyasi M, Ghafari R, Yazdani J.
Comparison of Ice Packs Application and Relaxation erapy
in Pain Reduction during Chest Tube Removal Following
Cardiac Surgery. N Am J Med Sci. 2014 Jan;6(1):19–24.
10. Chumkam A, Pongrojpaw D, Chanthasenanont A, Pattaraarchachai
J, Bhamarapravatana K, Suwannarurk K. Cryotherapy Reduced
Postoperative Pain in Gynecologic Surgery: A Randomized
Controlled Trial. Pain Res Treat. 2019;2019:2405159.
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11. Ravindhran B, Rajan S, Balachandran G, Mohan LN. Do
Ice Packs Reduce Postoperative Midline Incision Pain, NSAID
or Narcotic Use? World J Surg. 2019 Nov;43(11):2651–7.
12. Bovelander E, Weltings S, Rad M, van Kampen P, Pelger RCM,
Roshani H. e Inuence of Pain on the Outcome of Extracorporeal
Shockwave Lithotripsy. Curr Urol. 2019 Mar 8;12(2):81–7.
13. Cannata F, Spinoglio A, Di Marco P, Luzi M, Canneti A,
Ricciuti G, et al. Total intravenous anesthesia using remifentanil
in extracorporeal shock wave lithotripsy (ESWL). Comparison
of two dosages: a randomized clinical trial. Minerva Anestesiol.
2014 Jan;80(1):58–65.
14. Stocks JM, Taylor NAS, Tipton MJ, Greenleaf JE. Human
physiological responses to cold exposure. Aviat Space Environ
Med. 2004 May;75(5):444–57.
15. ienpont E. Does advanced cryotherapy reduce pain and
narcotic consumption aer knee arthroplasty? Clin Orthop
Relat Res. 2014 Nov;472(11):3417–23.
16. Palmieri RM, Garrison JC, Leonard JL, Edwards JE, Weltman
A, Ingersoll CD. Peripheral ankle cooling and core body
temperature. J Athl Train. 2006 Jun;41(2):185–8.
17. Vargas E Silva NCO, Rubio AL, Aleri FM. Pain Tolerance: e
Inuence of Cold or Heat erapy. J Chiropr Med. 2019 Dec;
18(4):261–9.
18. Myles PS, Myles DB, Galagher W, Boyd D, Chew C, MacDonald
N, et al. Measuring acute postoperative pain using the visual
analog scale: the minimal clinically important dierence and
patient acceptable symptom state. Br J Anaesth. 2017 Mar 1;118(3):
424–9.
19. Yayik AM, Ahiskalioglu A, Alici HA, Celik EC, Cesur S,
Ahiskalioglu EO, et al. Less painful ESWL with ultrasound-guided
quadratus lumborum block: a prospective randomized controlled
study. Scand J Urol. 2019 Dec;53(6):411–6.
20. Çi A, Benlioglu C. Eect of Dierent Musical Types on
Patient’s Relaxation, Anxiety and Pain Perception during
Shock Wave Lithotripsy: A Randomized Controlled Study.
Urol J. 2020 Jan 26;17(1):19–23.
Pimratana et al.
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91
Original Article
SMJ
Jureeporn Sri-in, M.Sc.*, Waraphorn Sisan, M.Sc.*, Phonphailin Kingkhangphloo, B.Sc.*, Pinpilai Jutasompakorn,
M.D.*,
Weerawadee Chandranipapongse, M.D.*, Somruedee Chatsiricharoenkul, M.D.*, Onchira Buranakan,
MD.**,
Arpha Pornseth, M.D.**, ammanoon Surachatkumtonekul, M.D.**
*Department of Pharmacology, ** Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, ailand.
Stability and Sterility of Extemporaneously Prepared
0.01% Atropine Ophthalmic Solution in Articial
Tears and Balanced Salt Solution
ABSTRACT
Objective: e aim of this study was to investigate the physicochemical and microbiological stability of extemporaneously
prepared 0.01% atropine ophthalmic solution in unopened eyedropper and in simulated use condition.
Materials and Methods: Two formulations of 0.01% atropine solutions, atropine in articial tear and atropine in
balanced salt solution (BSS), were prepared using 0.5 mL insulin syringes. In unopened conditions, 0.01% atropine
solutions were stored for six months at refrigerated temperature (2-8°C) or room temperature (25±2°C). Visual
inspection, atropine quantication, pH measurements, and sterility assay were analyzed at baseline, and every month
for six months. In simulated use condition, 0.01% atropine solutions stored at refrigerated and room temperature
were analyzed at 0, 15 and 30 days.
Results: In unopened conditions, both of 0.01% atropine formulations stored at refrigerated temperature showed
satisfactory stability. Atropine remained within 90% to 110% of the initial concentration up to six months. Under
room temperature, both formulations of atropine were less than 90% of their initial value aer 4 months storage. In
simulated use condition, atropine concentration was within 90% to 110% of initial value aer 30 days at refrigerated
and room temperature. All atropine solutions prepared in articial tear and BSS were free from bacterial contamination
throughout the study. No alteration of physical appearance (i.e., precipitation, discoloration) was observed, and
pH values also remained nearly unchanged.
Conclusion: Both formulations of 0.01% atropine are physicochemically stable for up to 6 months when kept
unopened in refrigerator, and for 1 month at refrigerated and room temperatures in simulated use condition.
Keywords: Myopia; atropine; stability; sterility; articial tear; balanced salt solution (Siriraj Med J 2022; 74: 91-99)
Corresponding author: ammanoon Surachatkumtonekul
E-mail: si95thim@gmail.com
Received 15 September 2021 Revised 28 October 2021 Accepted 17 November 2021
ORCID ID: https://orcid.org/0000-0002-0037-6863
http://dx.doi.org/10.33192/Smj.2022.12
INTRODUCTION
Myopia is an eye disorder and is the principal type of
refractive error. Previous population-based studies have
reported that the prevalence rates of myopia are highest
in East Asian populations.
1,2
eir ndings showed that
80% of schoolchildren in Taiwan, Hong Kong, and China,
as well as up to 96% of schoolchildren in South Korea,
suered from myopia.
3
It is estimated that myopia will
aect nearly 5 billion people by 2050.
2,4,5
Currently, there
are many methods for controlling myopia progression,
such as spectacles, contact lens, and pharmaceutical
strategies. Most of the studies in this eld use atropine
All material is licensed under terms of
the Creative Commons Attribution 4.0
International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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92
eye drops to reduce the rate of myopia progression in
children.
6
Atropine is a nonselective muscarinic antagonist, it
binds to and inhibit muscarinic acetylcholine receptors,
producing a wide range of anticholinergic eects. e
precise mechanisms underlying the ecacy of atropine
in slowing myopia progression are remains unclear.
Various hypotheses have been postulated, including the
action via muscarinic receptor pathways in the retina,
choroid and sclera. ese resulting in the prevention of
axial elongation, inhibition of scleral proliferation and
matrix synthesis. Moreover, atropine may be exerting
its eect via other receptors present in the eye.
7-9
Most “Atropine for the Treatment of Myopia (ATOM)”
studies focus on the ecacy and safety of 1%, 0.5%, 0.1%,
and 0.01% atropine in myopic Asian children aged 6-12
years old. eir ndings illustrated that 0.01% atropine is
eective for retarding myopia with minimal side eects,
compared with higher doses of atropine.
10-13
Recently,
the studies of Low-concentration Atropine for Myopia
Progression (LAMP) have demonstrated the ecacy
and safety of atropine concentrations of 0.05%, 0.025%,
and 0.01% in China in children aged 4-12 years old with
myopia. All these concentrations drastically reduced
the rate of myopia progression without any vision-
threatening side eects.
14
Generally, 0.01% atropine
is the most common strategy for managing childhood
myopia and is widely used all over the world, including
in Asian countries, such as Singapore, Taiwan, China,
and ailand.
2
e treatment period usually lasts for at
least 2 years, and may take longer if myopia progression
persists.
15
Since 0.01% atropine ophthalmic solution is not
commercially available in Thailand, eye drops are
prepared by ophthalmologists or hospital pharmacists.
e 1% commercial atropine is diluted with 0.9% sodium
chloride solution, balanced salt solution, or various
brands of articial tears depending on the discretion of
the ophthalmologist. Long-term treatment with atropine
is required for myopia control, and hence a longer shelf-
life is necessary to extend the follow-up intervals for
patients. However, there is little data concerning the
long-term stability of low-dose atropine eye drops. Only
two studies have been published demonstrating that
0.01% atropine in 0.9% sodium chloride solution with
or without preservatives is stable for six months in an
unopened container, both at room temperature and
refrigerated temperature.
16,17
However, there are no studies
on the stability of 0.01% atropine eye drops prepared
in articial tears (with preservatives) or balanced salt
solution (without preservatives). e lack of long-term
stability and sterility data limits the conservation period
of these preparations. Consequently, the aim of this study
was to determine the long-term chemical, physical, and
microbiological stability of extemporaneously prepared
atropine in artificial tears containing preservatives and in
balanced salt solution at refrigerated and room temperature.
e chemical, physical, and microbiological stability
of both formulations were also tested in simulated use
conditions.
MATERIALS AND METHODS
Reagents and materials
Atropine sulfate monohydrate, the reference
standard of atropine, and scopolamine hydrobromide,
the internal standard for atropine, were obtained from
e United States Pharmacopeial Convention, Inc., USA.
1% Atropine sulfate solution was obtained from Alcon-
Couvreur, Belgium. Balanced salt solution (BSS) was
obtained from Alcon Research LLC, USA. Hydroxypropyl
methylcellulose (HPMC), an articial tears solution
with sodium perborate as a preservative, was obtained
from Silom Medical Co., Ltd., ailand. LC/MS grade
acetonitrile and formic acid were obtained from Scharlau,
Barcelona, Spain. HPLC-grade methanol was obtained
from Fisher Scientic UK, the United Kingdom. Type I
water was produced using a Milli-Q water purication
system from Millipore Corporation, USA.
0.01% Atropine eye drops preparation
e preparation processes were undertaken by
scientists in a clean room of class 1.0×10
5
(air cleanliness
level of a maximum of 2.93×10
4
particles (≥0.5 µm)
per cubic meter). Two formulations of 0.01% atropine
ophthalmic solutions were prepared aseptically using a
0.5 mL insulin syringe:
- Atropine in preserved articial tears (HPMC),
prepared by dissolving 0.1 mL of 1% atropine
sulfate solution into 10 mL articial tears.
- Atropine in balanced salt solution, prepared by
dissolving 0.15 mL of 1% atropine sulfate solution
into 15 mL balanced salt solution (BSS).
Clear low-density polyethylene commercial eyedroppers
of HPMC and BSS were used as the containers in this
study.
Study design
e stabilities of the 0.01% atropine ophthalmic
solutions were studied at refrigerated temperature (2-8
°C) or room temperature (25±2 °C). e durations of the
study for the unopened eyedroppers and in simulated use
conditions were 6 months and 1 months, respectively.
Sri-in et al.
Volume 74, No.2: 2022 Siriraj Medical Journal
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93
Original Article
SMJ
In short, there were 4 subgroups in each study (for the
unopened eyedroppers and simulated use conditions)
as shown below:
(i) 0.01% atropine in HPMC at refrigerated temperature,
(ii) 0.01% atropine in HPMC at room temperature,
(iii) 0.01% atropine in BSS at refrigerated temperature,
(iv) 0.01% atropine in BSS at room temperature.
e eyedroppers stored at room temperature were
kept on the shelf, protected from light in their commercial
packages at 50%±10% residual humidity (RH).
Physicochemical and microbiological stability of
the 0.01% atropine ophthalmic solutions in simulated
use conditions
At day 0, 60 eyedroppers with two formulations
of 0.01% atropine solutions were prepared, with 15
eyedroppers for each subgroup (i–iv). For illustration
purposes, subgroup (i) with a total number of 15 eyedroppers
was used as an investigation process example. Each of the
15 eyedroppers was emitted daily (1 drop of the 0.01%
atropine solutions), that is, a drop was squeezed out
of the eyedropper and collected for analysis instead of
being dropped into the eye. Out of the 15 eyedroppers,
10 eyedroppers were obtained for visual inspection and
sterility assay. Next, 5 eyedroppers were tested at day 0,
15, and discarded. Another 5 eyedroppers were tested
at day 0 and 30. It is important to note the reason why
the eyedroppers were discarded aer the sterility assay
on day 15. Namely, subgroups (i) and (ii) both had an
approximate volume of 10 mL, while the sterility assay
required at least 4 mL. Hence, aer the daily emission and
two sterility assays, there would be an insucient amount
of solution remaining for another sterility assay and so
these were discarded. e remaining 5 eyedroppers from
the 15 totals were used for the atropine quantication
and pH measurements at days 0, 15, and 30.
Aer completing the 1-month study under simulated
use conditions, further investigations were planned, with the
aim to extend the experimental period of both formulations
at refrigerated temperature to 2 months. ere were 2
subgroups of eyedroppers here: (i) 6 eyedroppers of 0.01%
atropine in HPMC at refrigerated temperature, and (ii)
6 eyedroppers of 0.01% atropine in BSS at refrigerated
temperature. ese two subgroups were investigated
in the exact same manner as in the 1-month study. Out
of the 6 eyedroppers in each subgroup, 4 eyedroppers
were obtained for visual inspection and sterility assay at
day 0, one at another time point (days 15, 30, 45, or 60),
and one discarded (n = 1 for each time point/subgroup).
e remaining 2 from the 6 eyedroppers were used for
atropine quantication and pH measurements at days 0,
15, 30, 45, and 60 (n = 2 for each time point/subgroup).
Physicochemical and microbiological stability of
0.01% atropine ophthalmic solutions in the unopened
eyedroppers
In total, 120 eyedroppers of 0.01% atropine solutions
were prepared, comprising 30 eyedroppers for each
subgroup: atropine in HPMC at refrigerated temperature,
atropine in HPMC at room temperature, atropine in BSS
at refrigerated temperature, and atropine in BSS at room
temperature. In each subgroup, 5 unopened eyedroppers
were used for the analysis at days 30, 60, 90, 120, 150, and
180 (n = 5 for each time point/subgroup). Each eyedropper
was subjected to the following analyses: visual inspection,
atropine quantication, pH measurement, and sterility
assay. e baseline values for atropine quantication, pH
measurement, and the sterility assay were obtained from
the studies of the 0.01% atropine ophthalmic solutions
under the simulated use conditions.
Analyses
Quantication of atropine
The liquid chromatography with tandem mass
spectrometry (LC-MS/MS) method was applied for
quantitative analysis of the extemporaneously prepared
atropine solution. LC-MS/MS analysis was performed
using an Acquity Ultra Performance LC
TM
(Waters,
Co., Ltd. USA) coupled to a Quattro Premier XE Mass
Spectrometer (Micromass Technologies, UK) equipped
with an electrospray interface. For data acquisition and
processing, a MassLynx 4.1 SCN627 system (Micromass
Technologies, UK) was used.
Scopolamine hydrobromide was used as an internal
standard (IS). e chromatographic separation of atropine
and the internal standard was performed using a Kinetex
C18 column (50×2.10 mm, 1.7 µm; Phenomenex Ltd.,
USA). e mobile phase was an 85:15 (v/v) mixture of
0.1% (v/v) formic acid and acetonitrile in an isocratic
elution mode over a 2 min total run time. e ow rate
was 0.3 mL/min and the column temperature were set
at 30±5 °C. e injection volume was 1 μL. MS analyses
were carried out using the multiple reaction monitoring
(MRM) mode with positive electrospray ionization (ESI+).
e mass transition ion-pair was selected as m/z 290.1
to 124.1 for atropine and m/z 304.1 to 138.1 for the IS.
Validation of this method was performed according
to the International Conference on Harmonisation (ICH)
guidelines.
12
Linearity was determined by preparing
one calibration curve daily using six concentrations
of atropine (50, 100, 150, 200, 300, and 400 ng/mL),
obtained from atropine standard solution diluted in
diluent solutions (methanol and Milli-Q water at a ratio
of 1:1, v/v). e inuence of dierent weighting factors
(1/x and 1/x
2
) on the sum of the percentage relative error
Volume 74, No.2: 2022 Siriraj Medical Journal
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94
was evaluated and the results were compared with an
unweighted calibration curve. Accuracy was tested by
spiking the atropine reference standard with the atropine
test sample (at a concentration of 200 ng/mL) to obtain
three concentration levels, namely 80%, 100% and 120%, of
the test sample concentration. e accuracy was evaluated
on the basis of the calculated recovery values, and the
results should be found within the range of 95%-105%.
e precision of the methods was determined in terms of
the intra-day precision (repeatability) and intermediate
precision (within-laboratory reproducibility). e intra-
day precision was assessed by injecting six replicates
of three dierent concentrations of atropine standard
solutions (100, 200, and 300 ng/mL) on the same day. e
intermediate precision was determined by injecting the
same solutions for three consecutive days. e intra-day
and intermediate precisions are expressed as the relative
standard deviation (RSD, %). A value of less than 5%
was acceptable for both RSDs.
For sample preparation, 0.01% atropine solution from
each eyedropper was diluted with the diluent solution to
obtain a theoretical concentration of 200 ng/mL. A 100
µL aliquot of diluted atropine was transferred into a 1.5
mL micro tube and mixed with 20 µL internal standard
solution at a concentration of 1,000 ng/mL. e micro
tubes were thoroughly mixed by vortex mixing for 10
seconds. en, 1 µL of the mixed solution was collected
and transferred into an autosampler vial and submitted
to LC-MS/MS analysis.
In the chemical stability assessment, the baseline
concentration (day 0) was dened as 100% and the
subsequent concentrations of each time point were
calculated as percentages of the initial concentration.
Acceptance criteria for the stability were dened as
90%-110% of the baseline concentration (including the
limit of a 95% condence interval of the measures).
13,14
Visual inspection and pH measurements
During the study period, the physical appearance
of the solutions was examined when the samples were
taken from each eyedropper for the sterility assay. An
approximately 4 mL sample was dispensed from each
eyedropper into a 5 mL sterilized tube. Before sending the
sample for the sterility assay, the atropine solutions were
visually inspected under white light. e transparency,
color, and presence of visible particles or haziness were
noted.
For pH measurement, a 0.5 mL aliquot of 0.01%
atropine from each sample was transferred into a 2.0
mL micro tube. Hand-held pH testing was performed
on a SevenCompact S220 pH/ion meter with an InLab
Micro Pro-ISM electrode (Mettler Toledo, Switzerland),
which was calibrated at 25 °C in pH 4.01, 7.00, and 9.21
buer solutions (Mettler Toledo, Switzerland). e pH
change was considered acceptable if it did not vary by
more than one pH unit from the initial value.
14
Sterility assay
e sterility assay was carried out by the Department
of Microbiology, Faculty of Medicine Siriraj Hospital,
Mahidol University, in line with the United States
Pharmacopeia (USP) for pharmaceutical microbiology
testing.
15
First, 4 mL of 0.01% atropine solution from
each eyedropper was aseptically taken and sent to the
Department of Microbiology in a 5 mL sterilized tube for
the sterility assay, using a direct inoculation method. Each
sample was transferred directly to a uid thioglycolate
medium and soybean casein digest medium, and then
incubated at 30-35 °C and 20-25 °C, respectively, for 14
days. e culture medium was then carefully examined
for microbial growth.
RESULTS
Quantication of atropine
e retention times were 1.02 min for atropine
and 0.70 min for scopolamine. e method was shown
to be selective, as no interferences were observed at the
retention times corresponding to 0.01% atropine in the
articial tears or in the BSS (Figs 1A-E). e calibration
curve was linear for the concentrations ranging from
50-400 ng/mL and the determination coefficient R
2
was greater than 0.999 (Fig 1F). e weighting factor of
1/x was selected, since it was the one that reproduced
the least sum of percentage relative errors (%RE). is
method showed acceptable accuracy as the percentage
recovery ranged from 99.42%-102.18% in the three
dierent concentrations of atropine standard solutions. e
precision was satisfactory, with the RSD of the intra-day
and intermediate precision ranging from 1.05%-2.99%
and 1.66%-2.94%, respectively.
Chemical stability
In the simulated use study, both formulations
demonstrated chemical stability (concentration range
between 90%-110% of the initial concentration) for up to
30 days at room temperature and 60 days at refrigerated
temperature. e concentrations of the 0.01% atropine
solutions stored at room temperature were between
97.60%-99.44% of the initial concentrations in HPMC
and 102.26%-106.93% in BSS, and the 95% condence
interval was a maximum of +4.34%. For the 0.01% atropine
solutions stored in refrigerator, the concentrations were
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Fig 1. Chromatograms of: (A) BSS solution, (B) HPMC solution, (C) atropine reference standard spiked at 200 ng/mL, (D) atropine test
sample in BSS at 200 ng/mL, and (E) atropine test sample in HPMC at 200 ng/mL. (F) Calibration standard of atropine.
TABLE 1. Percentage of atropine concentration remaining (mean ± 95% CI) of 0.01% atropine for each formulation
and conservation condition in the simulated use study.
Storage
Solutions
Percentageofatropineconcentrationremaining(mean±95%CI)
conditions Day0 Day15 Day30 Day45 Day60
At room
HPMC 100 97.60±4.10 99.44±4.34
ND ND
temperature
(n=5) (n=5) (n=5) (n=5)
(25±2°C)
BSS 100 106.93±1.15 102.26±2.72
(n=5) (n=5) (n=5) (n=5)
ND ND
HPMC 100 101.44±2.20 104.86±2.47 96.57±1.53 105.80±3.53
Inrefrigerator (n=7)* (n=7) (n=7) (n=7) (n=2) (n=2)
(2–8°C) BSS 100 104.50±2.29 103.73±2.31 102.75±3.70 97.40±1.87
(n=7)* (n=7) (n=7) (n=7) (n=2) (n=2)
* n = 5 in the 1-month study and n = 2 in the 2-month study.
ND = not determined.
between 96.57%-105.80% of the initial concentration
in HPMC and 97.40%-104.50% in BSS, and the 95%
condence interval was a maximum of ±3.70%. e
chemical stability results for the simulated use conditions
are presented in Table 1.
In the unopened study, the 0.01% atropine in HPMC
and BSS stored at refrigerated temperature remained stable
up until 180 days of storage. e concentrations were
between 93.61%-102.99% of the initial concentrations in
HPMC and 92.66%-105.11% in BSS, with the maximal
and the 95% condence interval at a maximum of +4.61%.
At room temperature, the 0.01% atropine solutions were
still within an acceptable range for 60 days in HPMC and
for 90 days in BSS. e chemical stability results for the
unopened study are presented in Table 2. e chemical
stability trend for all the conditions are presented in
Fig 2.
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TABLE 2. Percentage of atropine concentration remaining (mean ± 95% CI) of 0.01% atropine for each formulation
and conservation condition in the unopened eyedroppers.
Storage
Solutions
Percentageofatropineconcentrationremaining(mean±95%CI)
conditions Day0 Day30 Day60 Day90 Day120 Day150 Day180
At room
HPMC 100 96.51±1.46 94.07±1.36 83.67±2.94 78.71±0.92 73.09±3.21 67.74±3.15
temperature
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
(25±2°C)
BSS 100 98.32±2.36 93.32±2.38 92.54±2.92 80.90±1.61 78.53±1.84 74.57±1.25
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
In
HPMC 100 100.71±1.69 102.99±3.19 100.30±1.62 93.61±1.53 95.17±1.95 99.62±1.38
refrigerator
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
(2–8°C)
BSS 100 100.57±2.04 105.11±3.93 104.27±3.32 92.66±1.63 99.34±3.78 101.58±4.61
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
* Baseline values of the atropine concentration were obtained from the studies of 0.01% atropine ophthalmic solutions in 1-month simulated
use conditions.
Fig 2. (A) Percentage of atropine concentration remaining (mean ± 95% CI) for each formulation and conservation condition in the simulated
use study. (B) Percentage of atropine concentration remaining (mean ± 95% CI) for each formulation and conservation condition in the
unopened eyedroppers.
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Visual inspection and pH measurements
All the samples that were sent for the sterility assay
(from 168 eyedroppers) remained clear and colorless,
with no precipitation or visible particles observed during
the study period in all the study conditions. e pH of all
the samples showed insignicant changes throughout the
study. For both formulations, when stored at refrigerated
temperature and room temperature, the pH did not vary
by more than 0.20 and 0.23 pH units from the initial
value for the simulated use conditions and unopened
conditions, respectively (Table 3 and 4).
Sterility assay
e results indicated that the sterility was preserved
in all the samples, i.e., for every subgroup in the simulated
use and unopened conditions. No microbiological growth
was observed when incubated for 14 days at 30-35 °C in
uid thioglycolate medium and at 20–25 °C in soybean
casein digest medium.
TABLE 3. e pH value of 0.01% atropine sulfate for each formulation and conservation condition in the simulated
use study.
TABLE 4. e pH value of 0.01% atropine sulfate for each formulation and conservation condition in the unopened
eyedroppers.
Storage
Solutions
pH value (mean ± SD)
conditions Day0 Day15 Day30 Day45 Day60
At room
HPMC 6.93±0.02 6.90±0.04 6.92±0.01
ND ND
temperature
(n=5) (n=5) (n=5) (n=5)
(25±2°C)
BSS 7.02±0.04 6.82±0.08 6.88±0.04
ND ND
(n=5) (n=5) (n=5) (n=5)
In
HPMC 6.95±0.05 6.86±0.05 6.93±0.02 6.89±0.02 6.90±0.03
refrigerator
(n=7)* (n=7) (n=7) (n=7) (n=2) (n=2)
(2–8°C)
BSS 6.98±0.08 6.92±0.06 6.90±0.06 6.81±0.05 6.78±0.07
(n=7)* (n=7) (n=7) (n=7) (n=2) (n=2)
* n = 5 in the 1-month study and n = 2 in the 2-month study.
ND = not determined.
Storage
Solutions
pH value (Mean ± SD)
conditions Day0 Day30 Day60 Day90 Day120 Day150 Day180
At room
HPMC 6.93±0.02 6.91±0.01 6.92±0.01 6.91±0.01 6.83±0.00 6.85±0.01 6.90±0.02
temperature
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
(25±2°C)
BSS 7.02±0.04 6.86±0.05 6.89±0.02 6.81±0.07 6.79±0.10 6.81±0.06 6.83±0.05
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
In
HPMC 6.97±0.03 6.90±0.01 6.88±0.03 6.92±0.01 6.87±0.01 6.91±0.03 6.92±0.03
refrigerator
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
(2–8°C)
BSS 7.02±0.04 6.88±0.04 6.85±0.06 6.85±0.04 6.85±0.02 6.86±0.05 6.88±0.05
(n=30) (n=5)* (n=5) (n=5) (n=5) (n=5) (n=5) (n=5)
* Baseline values of the pH measurement were obtained from the studies of 0.01% atropine ophthalmic solutions in the 1-month simulated
use conditions.
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DISCUSSION
To assess the accuracy of the extemporaneous
prepared ophthalmic solutions in clinical practice, this
study investigated the accuracy of using 0.5 mL and
1 mL insulin syringes compared to an auto pipette for
the extemporaneous preparation. e 0.01% atropine
solutions were prepared using an auto pipette, and 0.5
mL and 1 mL insulin syringes. Here, 0.1 mL of 1%
atropine sulfate was mixed with 9.9 mL of HPMC and
0.15 mL of 1% atropine sulfate was mixed with 14.85 mL
of BSS (n =5 for each apparatus in each formulation).
e preparation using the 1 mL insulin syringe was the
same as for the preparation using the 0.5 mL insulin
syringe. e mean concentration of atropine in HPMC
compared to the expected concentration ranged from
98.24%-104.37%, 100.25%-102.91%, and 154.29%-
157.05% for the auto pipette, and the 0.5 mL and 1 mL
insulin syringes, respectively. e mean concentration of
atropine in BSS ranged from 98.00%-103.03%, 100.01%-
104.79%, and 140.63%-145.89% for the auto pipette, and
the 0.5 mL and 1 mL insulin syringes, respectively. In
this study, a 0.5 mL insulin syringe was then used in the
preparation process, since it was more accurate than the
1 mL insulin syringe.
In the stability assessment of the ophthalmic solutions,
the physicochemical and microbiological stability should
be evaluated. Previous recent studies have also focused on
the long-term stability of ophthalmic atropine solutions.
Saito et al.
16
demonstrated that the physical, chemical,
and microbiological stability of 0.01%, 0.10%, 0.25%, and
0.5% atropine in 0.9% sodium chloride solution were
maintained for at least 6 months when stored unopened
in polyethylene bottles at 25 °C or 5 °C. Berton et al.
17
showed that 0.01% atropine in 0.9% sodium chloride
solutions with and without antimicrobial preservative
were physicochemically stable for 6 months when stored
unopened in low-density polyethylene bottles at 25 °C.
e aim of our study was to investigate the long-term
stability of 0.01% atropine in HPMC and BSS when
stored unopened at room temperature (25 °C) or at
refrigerated temperature (5 °C), and the stability of the
0.01% atropine solutions in a simulated use condition
for up to 2 months.
In the simulated use study, 0.01% atropine in
HPMC and BSS demonstrated physicochemical and
microbiological stability for up to 30 days at room and
refrigerated temperature. For the 2-month extension
study at refrigerated temperature, 0.01% atropine in
HPMC and BSS also maintained its physicochemical and
microbiological stability throughout the study period.
In the unopened conditions, 0.01% atropine in HPMC
and BSS stored at refrigerated and room temperature
showed both physical and microbiological stability over 6
months. e pH values remained nearly constant, and no
visual changes or microbial contamination were observed
over the study period. Regarding the chemical stability,
the mean atropine concentrations in HPMC and BSS
remained well within 90%-110% of the initial concentration
for 6 months at refrigerated temperature. However at
room temperature, the mean atropine concentrations in
HPMC and BSS were considered to be at an acceptable
level of stability for only 2 and 3 months, respectively.
ese results supported the eect of temperature on the
chemical stability. e dierences in chemical stability
at room temperature between our study and previous
studies
16-18
are particularly related to the formulation.
In previous studies, atropine was mostly prepared in
0.9% sodium chloride solution with a pH value of 5.3-
6.2, compared to the pH value ranging from 6.8-7.0 for
atropine in HPMC and BSS. e stability of atropine
sulfate solution is enhanced in acidic conditions, as it has
a lower degree of hydrolysis. Atropine sulfate solution is
most stable at a pH between 3–6, and the ideal storage pH
ranges between 3-4.
19-20
However, ophthalmic solution
should better fall within the ocular comfort range (pH
6.6–7.8) to avoid eye discomfort and irritation.
21
From the results from the unopened study, the
conservation period of 0.01% atropine in HPMC and
BSS could be ensured for 6 months when stored at 5 °C
and for 2 months when stored at 25 °C.
Hence, the follow-up intervals for patients receiving
these formulations could be extended to up to 6 months
when a refrigerator is available.
ere are some limitations of this study to note. First,
the number of samples in the 2-month extension simulated
use study was limited. Second, the room temperature in
this study was 25±2 °C, which is actually lower than the
average indoor temperature in most parts of ailand.
Since the storage temperature significantly aects the
chemical stability, the conservation period for 0.01%
atropine in HPMC and BSS outside the refrigerator
might be, consequently, shorter than in our study.
CONCLUSION
is study demonstrated that 0.01% atropine solution
both in HPMC and BSS retained good physicochemical
and microbiological stability for 6 months both when
le unopened and when stored at 5±3 °C; whereas, the
atropine concentration in unopened eyedroppers stored
at 25±2 °C generally declined over time. is study also
confirmed the physicochemical and microbiological
stability of both formulations at 5±3 °C or 25±2 °C for 30
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days aer opening. In conclusion, the extemporaneously
prepared 0.01% atropine ophthalmic solution both in
HPMC and BSS could be kept for up to 6 months in the
refrigerator at a temperature of 2-8 °C until the bottle is
opened.
ACKNOWLEDGEMENTS
The authors wish to thank the Department of
Microbiology Faculty of Medicine Siriraj Hospital,
Mahidol University for their analysis of the sterility tests.
Potential conicts of interest
e authors have no conicts of interest with the
manufacturers or suppliers of any of the products or
materials in this study. It is to be noted though that
the authors were supported by a Chalermprakiat grant
from the Faculty of Medicine Siriraj Hospital, Mahidol
University.
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14. Sautou V, Brossard D, Chedru-Legros V, Crauste-Manciet
S, Fleury-Souverain S, Lagarce F. Methodological guidelines
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Part 1: liquid preparations. SFPC and GERPAC; 2013.
15. e United States Pharmacopeia 42-e National Formulary
37. United States Pharmacopeial Convention. Inc., Rockville,
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16. Saito J, Imaizumi H, Yamatani A. Physical, chemical, and
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17. Berton B, Chennell P, Yessaad M, Bouattour Y, Jouannet M,
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100
Gobhathai Sittironnarit, M.D., Rungsipohn Sripen, M.Sc., Sucheera Phattharayuttawat, Ph.D.
Department of Psychiatry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, ailand.
Psychometric Properties of the Thai Mental Health
Literacy Scale in Sixth-Year Medical Students
ABSTRACT
Objective: To assess the psychometric properties of the ai Mental Health Literacy Scale (TMHLS) in sixth-year
medical students.
Materials and Methods: By using the purposive sampling method, we enrolled 202 participants in this study.
Descriptive statistics were used to analyze demographic data. e index of item-objective congruence (IOC) was
used to verify content validity. Exploratory factor analysis (EFA) was performed to establish the construct validity
of the TMHLS. e internal consistency was estimated by computing Cronbach’s coecient alpha.
Results: e TMHLS had good content validity (IOC=.85) and construct validity. e EFA resulted in ve factors,
which included 32 of the 35 items and accounted for 46.86% of the variance. e factors were the ability to recognize
mental disorders; condentiality of mental health practitioners; skills of mental health information seeking; beliefs
about mental illnesses; and attitudes toward patients with mental illness. e reliability coecient of the TMHLS
total test was .851, and reliability coecient in subdomains were range from .197 to .872. Individuals who had a
mental health professional as an intimate contact and individuals who had a history of seeking help from mental
health professional(s) in person showed signicantly higher mental health literacy than those who did not.
Conclusions: e TMHLS has good psychometric properties. Dynamic knowledge transfer and exchange with a
close mental health professional should be applied to promote mental health literacy in medical students.
Keywords: assessment; experience; help-seeking; medical externs; professional; reliability; validity (Siriraj Med J
2022; 74: 100-107)
Corresponding author: Gobhathai Sittironnarit
E-mail: gobhathai.kua@mahidol.edu
Received 1 October 2021 Revised 26 October 2021 Accepted 16 November 2021
ORCID ID: https://orcid.org/0000-0001-8902-4903
http://dx.doi.org/10.33192/Smj.2022.13
INTRODUCTION
Mental health problems have been increasing
throughout the world
1
, with young adults being the
most aected group. irty percent of them have mental
disorders while the remaining are also at risk.
2
Because of
poor mental health literacy, high mental health problems
and low engagement in help-seeking behaviors were
reported in these individuals.
3-7
Mental health literacy reduces the risk of developing
mental disorders along with increasing help-seeking
behaviors.
8
People with high mental health literacy will
be able to recognize, manage, and prevent mental health
problems. Oppositely, people with low mental health
literacy may not be able to appropriately manage and oen
end up with more serious complications.
9
Unfortunately,
there is no assessment tool for mental health literacy in
ai at the time.
Sixth-year medical students were targeted in this
study because they were young adults at risk of mental
disorders
2,10-11
who already gained mental experiences
that may aect their mental health literacy.
12-13
Due to the lack of an instrument to measure mental
health literacy among ai people, this study aimed to
assess the psychometric properties of the ai mental
Sittironnarit et al.
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the Creative Commons Attribution 4.0
International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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health literacy scale (TMHLS) in sixth-year medical
students who may exemplify the young adults at risk
of mental disorder.
MATERIALS AND METHODS
Participants
e number of participants in this study was determined
by the Cochran formula.
14
We enrolled 250 sixth-year
medical students from the Faculty of Medicine Siriraj
Hospital in Bangkok who had registered for the rst
semester in academic year 2017 and voluntarily answered
the questionnaires using purposive sampling method.
Tools
A demographic questionnaire was used to collect
data from participants including gender, age, sources
of mental health experiences, and their mental illness
if applicable.
e translation of mental health literacy scale (MHLS)
The MHLS was translated to Thai under the
supervision of a language expert. e index of item-
objective congruence (IOC) was used to verify content
validity by three mental health experts: one psychiatrist
and one licensed clinical psychologist from the Department
of Psychiatry, Faculty of Medicine Siriraj Hospital; and
one licensed clinical psychologist from the Faculty of
Psychology, Chulalongkorn University. All mental health
experts discussed the translated version until reaching a
consensus. e ai mental health literacy scale (TMHLS)
was nally completed following expert opinion.
e TMHLS is a self-reporting questionnaire with
35 items covering six attributes of mental health literacy:
the ability to recognize a disorder; knowledge of where to
seek information; knowledge of risk factors and causes;
knowledge of self-treatment; knowledge of professional
help available and attitudes that promote recognition or
appropriate help-seeking behavior. e total score is the
summation of all items. erefore, the maximum score
is 160 whereas the minimum score is 35. A higher score
means greater mental health literacy.
Statistical analyses
All statistical analyses were performed by PASW 18.0.
16
Descriptive statistics were used to analyze demographic
data. e IOC was used to verify content validity. e
factor solution was determined based on the number
of eigenvalues greater than one.
17
We conducted the
exploratory factor analysis (EFA) using .30 as a factor
loading criterion
18
, ve to ten participants per item
19
, and
a minimum sample size of 200.
20-21
e EFA began with
an initial analysis run to obtain eigenvalues for each factor
in the data. e Kaiser-Meyer-Olkin (KMO) Measure of
Sampling Adequacy test and Bartlett’s Test of Sphericity
were executed to determine construct validity and to
conrm those data were appropriate. e KMO test was
used to verify the sampling adequacy for the analysis,
and Bartlett’s Test of Sphericity was used to determine
if correlations between items were suciently large for
EFA. Bartlett’s Test of Sphericity should reach a statistical
signicance of less than .05 in order to conduct an EFA.
e reliability of an instrument is concerned with the
consistency, stability, and dependability of the scores.
22
For this reason, the internal consistency was tested using
Cronbach’s alpha for each competency.
RESULTS
e sixth-year medical students
Two-hundred and two of the 250 participants (80.8%)
answered the questionnaires. e majority of respondents
were female (n=133; 65.8%) aged between 22-24 years
(M = 23, SD = 0.46). Psychiatric rotation was the most
popular source of their mental health experience (n=190;
94.1%). irteen out of 202 medical students had major
depressive disorder (6.4%), the most common diagnoses
among the samples (Table 1).
e psychometric properties of the ai mental health
literacy scale (TMHLS)
Content validity
e rst-round IOC of the TMHLS was .67 with 9
of 35 items (items number 2, 3, 5, 6, 7, 8, 15, 20 and 24)
dened as required revision (IOC > .05). Aer revision
of those 9 items, content validity in the second round
increased to .85. However, 4 of 9 items (items number
3, 5, 15 and 20) were still dened as required revision
(IOC > .05).
Construct Validity
e EFA revealed ve meaningful constructs emerged,
namely, ability to recognize mental disorders (item
1, 2, 3, 4, 5, 6, 7, 8); condentiality of mental health
practitioners (item 22, 23, 25, 26, 27, 28); skills of mental
health information seeking (item 16, 17, 18, 19); beliefs
about mental illnesses (item 9, 11, 12, 13, 20, 21, 24);
and attitudes toward patient with mental illness (item
29, 30, 31, 32, 33, 34, 35), which accounted for 46.86%
of the cumulative variance. ree items (item 10, 14 and
15) did not load on any of the factors (Table 2).
Reliability
Total Cronbach’s alpha coecient of the TMHLS
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Attributes Frequency Percent
(n) (%)
Responserates 202 80.8
Sex Female 133 65.8
Male 69 34.2
Age(years) 22 22 10.9
23 158 78.2
24 22 10.9
(M=23,SD=0.46,Range22-24years)
Sources of mental health experiences
(Mutual items and answers reasonable)
• Fifth-year rotation (psychiatry) 190 94.1
• Media (internet/ newspaper/ television) 139 68.8
• Having family members or friends with mental disorder(s) 110 54.5
• Self-experience of mental disorder(s) 31 15.3
• Havingamentalhealthprofessionalasanintimatecontact 29 14.4
• History of seeking help from mental health professional(s) in person 19 9.4
• History of seeking help from mental health professional(s) 16 7.9
for family members or friends
Types of mental illness
• Major depressive disorder (MDD) 13 6.4
• Panic disorder 3 1.5
• Adjustmentdisorder 2 1
• Attentiondecithyperactivitydisorder(ADHD) 2 1
• Bipolar disorder 1 0.5
• Premenstrual dysphoric disorder (PMDD) 1 0.5
• Relationship problems 1 0.5
• Unspecied 8 4
TABLE 1. Demographic data of the sixth-year medical students (n=202).
was .851. Still, there were 6 items (items 9, 10, 11, 12,
15 and 20) in the reliability coecients of all items that
do not meet the criterion (CITC < .20). e Cronbach’s
alpha if item deleted was .872 which was in the same
interval before withdrawing the 6 items. e Cronbach’s
alpha if item deleted for each item was slightly dierent
from the Cronbach’s alpha of all items. Therefore,
all items that do not meet the criterion still remain
(Table 3). e reliability coecient in subdomains of
TMHLS were range from .197 to .872 (Table 4).
e mental health literacy in sixth-year medical students
e medical students’ mean score of mental health
literacy was 123.09 (S.D. ± 11.55, 95% CI = 121.49–124.69).
Multiple comparisons of our participants’ mental health
experiences showed having intimate contact with a mental
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TABLE 2. Factor structure of the ai Mental Health Literacy Scale (TMHLS).
Item F1 F2 F3 F4 F5
Q8 .866
Q5 .831
Q7 .752
Q3 .714
Q6 .696
Q4 .662
Q1 .648
Q2 .540
Q28 .697
Q27 .683
Q26 .612
Q22 .529
Q25 .524
Q23 .397
Q19 .799
Q17 .791
Q16 .753
Q18 .634
Q11 .558
Q20 -.502
Q21 -.461
Q24 -.442
Q13 .422
Q12 -.351
Q9 .337
Q33 .781
Q32 .775
Q30 .758
Q31 .747
Q34 .725
Q35 .725
Q29 .724
Note: F1 =ability to recognize mental disorders, F2 = condentiality of mental health practitioners, F3 = skills of mental health information
seeking, F4 = beliefs about mental illnesses, F5 = attitudes toward patient with mental illness
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TABLE 3. Reliability coecients of all 35 Items from the ai Mental Health Literacy Scale (TMHLS).
Items ScaleMeanScaleVarianceCorrectedItem- Cronbach'sAlpha
ifItemDeletedifItemDeletedTotalCorrelation ifItemDeleted
1 120.0050 127.146 .388 .847
2 120.1608 126.206 .440 .845
3 119.7186 127.203 .444 .846
4 120.0101 125.677 .442 .845
5 119.6734 125.160 .509 .844
6 120.0151 127.096 .339 .848
7 119.8442 126.263 .402 .846
8 119.6482 124.320 .544 .843
9 120.1709 132.405 .124** .853
10 120.4121136.213-.122** .857
11 119.9447 133.113 .089** .853
12 120.6783 133.586 .028** .856
13 119.9146 130.887 .223 .850
14 119.6131 128.370 .394 .847
15 120.3568 131.443 .140** .853
16 119.1005 129.444 .318 .848
17 119.1256 129.878 .295 .849
18 118.9447 129.578 .292 .849
19 118.8543 129.085 .399 .847
20 120.4472 131.945 .077** .857
21 119.2563 125.616 .367 .847
22 118.9095 126.770 .384 .847
23 119.1859 126.657 .413 .846
24 118.9548 124.649 .492 .844
25 119.3920 129.179 .254 .850
26 118.7286 126.936 .420 .846
27 118.7337 127.762 .414 .846
28 118.6734 128.504 .374 .847
29 120.4573 125.886 .411 .846
30 119.7688 125.360 .461 .845
31 119.3618 123.444 .572 .842
32 119.5879 124.233 .494 .844
33 120.4874 124.776 .414 .846
34 120.0050 124.601 .401 .846
35 119.6784 124.957 .454 .845
**Items that have corrected item-total correlation less than 2 are not pass the criterion.
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TABLE 4. Reliability coecients in subdomain and total of the ai Mental Health Literacy Scale (TMHLS).
Factors Number Cronbach'sAlpha
(subdomain) ofItems coefcient
F1 8 .867
F2 6 .683
F3 4 .782
F4 7 .197
F5 7 .873
Note: F1 =ability to recognize mental disorders, F2 = condentiality of mental health practitioners, F3 = skills of mental health information
seeking, F4 = beliefs about mental illnesses, F5 = attitudes toward patient with mental illness; Total Cronbach's alpha coecient =.851
health professional and a history of seeking help from
a mental health professional(s) in person signicantly
correlated with the participants’ mental health literacy
score. e mental health literacy of individuals who had
intimate contact with a mental health professional was
signicantly higher than those who did not (mean±SD
was 127.41±13.96 and 122.37±10.99, respectively; t (200)
= 2.196, p < .05). Likewise, mental health literacy of
individuals who had a history of seeking help from
mental health professional(s) in person was higher than
those who did not (mean±SD was 128.84±10.25 and
122.50±11.55, respectively; t (200) = 2.302, p < .05.)
(Table 5).
TABLE 5. e comparison of mental health literacy by mental health experiences.
Mental health experiences n x S.D. t p
Media (internet/ newspaper/ television)
have 139 123.98 11.94 1.622 .106
nothave 63 121.14 10.49
Having family members or friends with a mental illness
have 110 123.83 11.78 .986 .325
nothave 92 122.22 11.28
Self-experienceofmentaldisorder(s)
have 31 126.16 10.13 1.612 .108
nothave 171 122.54 11.74
Having a mental health professional as an intimate contact
have 29 127.41 13.96 2.196* .029
nothave 173 122.37 10.99
History of seeking help from mental health professional(s)
in person
have 19 128.84 10.25 2.302* .022
nothave 183 122.50 11.55
History of seeking help from mental health professional(s)
for family members or friends
have 16 124.94 10.85 .664 .507
nothave 186 122.94 11.63
* p < .05
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106
DISCUSSION
e sixth-year medical students
Major depressive disorder was the most common
diagnosis in this study which was in accordance with
previous ai, Malaysian and Chinese Studies.
23-25
e Psychometric properties of the ai mental health
literacy scale (TMHLS)
e TMHLS has good validity. e content validity
by the IOC in the second-round was .85, and only 4
out of 9 items needed to be revised. According to the
original study
15
that stated measurement cannot assess
all attributes of mental health literacy when some of
the items needed to be removed, all items were used in
the scale altogether. Consistent with a previous Persian
study
26
, the EFA of data resulted in ve meaningful factors
that were similar to the original ones
15
, and accounted
for 46.86% of the variance. e trivial dierences could
have been due to cultural diversities of the participants.
Socioeconomic status, cultural and language variances
interact with health literacy.
27
Total Cronbach’s alpha coecient of the TMHLS
was .851 which was considered in a good criterion. e
reliability coecient in subdomains were range from
.197 to .872. Still, there were 6 items that did not meet
the criterion. e Cronbach’s alpha if item deleted for
each item was slightly dierent from the Cronbach’s
alpha of all items. According to the original study
15
that
stated the measurement cannot assess all attributes of
mental health literacy when some of the items needed to
be removed. erefore, those 6 items that do not meet
the criterion were persevered.
e mental health literacy in sixth-year medical students
e mental health literacy of our medical students
was aligned but slightly lower than a prior British study.
13
Our score was marginally inferior than an Australian
study exploring university students.
15
is may uncover
dierences in mental health literacy between developing
and developed countries. e necessity of mental health
literacy acknowledgement in village health workers was
mentioned in a previous ai study.
28
A South African
study urged for mental health education in healthcare
professionals.
29
Language deviance and questionnaire
format may also be responsible for the dierent results.
Our participants had already gained mental health
experiences that may aect their mental health literacy.
Previous works also showed higher mental health literacy
in individuals who encountered mental health problems
than the individuals who did not.
12,30
e more exposure
someone has, the more mentally health literate they are.
12
Consistent with the original study
15
, the mental health
literacy of individuals who had a history of seeking help
from mental health professional(s) in person was higher
than those who did not. Dynamic knowledge transfer
and exchange with a close mental health professional,
like in family businesses
31
, could be a reason for higher
mental health literacy of individuals who had a mental
health professional as an intimate partner than those
who did not.
e questionnaire comments
The main concern about the TMHLS was the
complexity and clarity of the questions. However, the
items that should be allocated were not mentioned. A
separate version of TMHLS between medical students
and general population was advised. Although some
participants described the questionnaire as easy and
clear to answer, an equal number expressed the overly
theoretical concerns. Some of them requested more
attitude questions.
Limitations
Information and recall bias may have been presented
in this observational descriptive cross-sectional study.
Based on purposive sampling method, the results cannot
legitimize any generalizations. We did not perform
back-translation process; hence the quality assurance of
the TMHLS should be concerned. As the EFA is not a
sucient tool to test the theoretical foundations of the
instrument, a conrmatory factor analysis (CFA) should
be conducted to further the knowledge in this area. Since
we used Cronbach’s alpha for reliability testing, the
interitem covariance and the measurement assumptions
error could be considered as the alpha value cannot be
equivalent with the reliability of the test score. Additional
studies in other population are recommended to validate
this instrument to widen its application.
CONCLUSION
e TMHLS has good validity and reliability. Dynamic
knowledge transfer and exchange with a close mental
health professional should be applied to promote mental
health literacy in medical students.
ACKNOWLEDGEMENT
We gratefully acknowledge Matt O’Connor, Ph.D.
for his kind permission to allow us to use MHLS in
this work; the Postgraduate Education Division and
Deputy Dean of Undergraduate Education of Faculty
of Medicine Siriraj Hospital for the scholarship and
permission to collect data, correspondingly. We also
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thank all expert validators, Boonjira ungsuk, M.A.
(English); Tikumporn Hosiri, MD; Panida Yomaboot,
Ph.D. and Kullaya Pisitsungkagarn, Ph.D. for their
superb suggestions about the TMHLS. And last but
not least, we thank all the participants in this study for
their contribution.
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108
Natthakrit Anansitthikorn, M.D., Suchanan Hanamornroongruang, M.D.
Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, ailand.
Two-Antibody Staining Method, A Cost-Saving
Strategy for Universal Lynch Syndrome Screening
in Endometrial Cancers
ABSTRACT
Objective: Lynch syndrome is an autosomal dominant disorder that increases the risk of cancers in many sites. In
women, endometrial cancer is oen a sentinel tumor and thus immunohistochemistry for mismatch repair (MMR)
proteins MLH1, MSH2, MSH6 and PMS2 is encouraged as a screening test. To reduce cost, staining for only 2
MMR proteins PMS2 and MSH6 has been proposed. is study aimed to determine whether a 2-antibody staining
test is enough to screen for Lynch syndrome in endometrial cancer patients.
Materials and Methods: Cases of endometrial carcinoma with immunohistochemistry for 4 MMR proteins were
reviewed. Results of immunohistochemistry screening were compared between all four antibodies and only two
(PMS2 and MSH6) antibodies.
Results: Loss of expression of any MMR proteins was detected in 51 out of 203 cases (25.12%). Twenty-three cases
(45%) showed loss of MLH1 and PMS2; 13 cases (25%) showed loss of MSH2 and MSH6; ve cases (10%) showed
loss of MSH6; seven cases (14%) showed loss of PMS2 and three cases (6%) showed loss of MSH2. e 2-antibody
method detected 48 cases (94%) with a MMR deciency but failed to detect three cases (6%) with an isolate loss
of MSH2. e screening results from the 2-antibody method are 98.5% (200/203) in accordance with the original
4-antibody method.
Conclusion: e 2-antibody method is a quite eective option to screen for Lynch syndrome in endometrial cancers.
However, MSH2 mutations may be missed in a few cases.
Keywords: Endometrial carcinoma; Lynch syndrome; MMR proteins; MSH2 loss (Siriraj Med J 2022; 74: 108-113)
Corresponding author: Suchanan Hanamornroongruang
E-mail: suchananice@hotmail.com
Received 12 October 2021 Revised 6 December 2021 Accepted 13 December 2021
ORCID ID: https://orcid.org/ 0000-0003-4392-0811
http://dx.doi.org/10.33192/Smj.2022.14
INTRODUCTION
Lynch syndrome (LS) is an autosomal dominant
disorder which is caused by a germline mutation in mismatch
repaired (MMR) genes (MLH1, MSH2, MSH6 and PMS2)
or EpCAM deletion.
1
is syndrome is associated with
cancer in many organs such as the lower gastrointestinal
tract, endometrium, ovary, stomach, pancreas and brain.
2
However, the two most well-known cancers associated
with LS are colorectal and endometrium. Women with
LS have a lifetime risk of developing colorectal cancer
and endometrial cancer at 50%-85% and 40%-60%,
respectively.
3,4
Although the prevalence of LS in the
general population remains elusive
1
, about 1.7%-5% of
endometrial cancers are associated with this syndrome.
1,5-10
For women with LS, endometrial cancer is oen a
sentinel tumor.
11
According to a study by Meyer et al,
61% of women with LS linked endometrial cancer had
a second primary cancer, mostly colorectal cancer.
3
Identication of LS patients is the rst step in achieving
proper cancer surveillance and management. Clinical
Anansitthikorn et al.
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International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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screening criteria such as Amsterdam II and revised
Bethesda guidelines have failed to detect a signicant
number of LS patients.
2,10,12
us, tumor-based testing -
immunohistochemistry (IHC) for MMR proteins (MLH1,
MSH2, MSH6 and PMS2) and/or microsatellite instability
(MSI) - is recommended.
1-4,9,13,14
Both IHC and MSI have a high sensitivity and
specicity, however, IHC is more practical and cost
eective.
3,4
In addition, MSI is less sensitive to the MSH6
germline mutation.
1,2
Many studies claim that IHC for
only PMS2 and MSH6 is sucient for initial screening
15-18
due to the binding properties of MMR heterodimer
complexes; MSH2 binds with MSH6 and MLH1 binds
with PMS2. With a 2-antibody approach, universal LS
screening in endometrial cancers is easier to achieve,
especially in places with limited resources. According to
an international survey on LS screening in gynecologic
cancers by Ryan et al, most pathologists still prefer the
4-antibody method.
19
In our experience and personal
communication with pathologists and gynecologists, most
were not condent or did not acknowledge in this cost-
saving method. Moreover, most studies on a 2-antibody
approach were conducted in cases of colorectal cancer.
us, the purpose of this study was to determine the
utility of the 2-antibody method in cases of endometrial
cancer compared to the original 4- antibody method.
MATERIALS AND METHODS
e study was conducted at the Department of
Pathology, Faculty of Medicine Siriraj Hospital, Mahidol
University, Bangkok, ailand and was approved by the
Siriraj Institutional Review Board (COA no. Si058/2020).
All cases of endometrial carcinoma with an
immunohistochemistry conducted for the 4 MMR proteins
between January 1
st
, 2010 and December 31
st
, 2019 were
included in this study. Cases without available H&E and
immunostained slides were excluded. Immunohistochemical
staining was performed by the Ventana BenchMark
ULTRA autostainer. Monoclonal antibodies for MMR
proteins were as follows: anti-MLH1 (M1; Ventana),
anti-PMS2 (EPR3947; Cell marque; USA), anti-MSH2
(G219-1129; Cell marque; USA) and anti-MSH6 (44;
Ventana; USA). Intact expression was dened as positive
nuclear staining within tumor cells. Loss of expression
was dened as absence of nuclear staining within tumor
cells. Stromal cells and nonneoplastic epithelial cells
were used as internal control. Cases with absence of
staining in internal control cells were excluded from the
study. Focal and weak nuclear staining was considered
as “cannot be determined”.
All H&E and immunostained slides were reviewed.
Results of immunohistochemistry screening were recorded
and compared between all four antibodies against two
(PMS2 and MSH6) antibodies. Clinical information
including age at diagnosis, specimen type was retrieved
from database records.
RESULTS
A total 203 cases of endometrial carcinoma with
an age range of 23-62 were included in this study. Most
specimens (97.54%) were from total or subtotal hysterectomy.
Endometrioid carcinoma was the most common histologic
subtype (89.66%). Specimen characteristics are summarized
in Table 1. Loss of expression of any MMR protein was
detected in 51 out of 203 cases (25.12%). Of these 51
cases with MMR deciency, 23 cases (45%) showed
loss of MLH1 and PMS2; 13 cases (25%) showed loss of
MSH2 and MSH6; ve cases (10%) showed loss of MSH6;
seven cases (14%) showed loss of PMS2 and three cases
(6%) showed loss of MSH2 (Table 2). e 2-antibody
method detected 48 cases (94%) with MMR deciency
but failed to detect three cases (6%) with an isolate loss
of MSH2. Isolate loss of MLH1 was not observed. One
MSH2-absent/ MSH6-intact case was dedierentiated
carcinoma while the others were endometrioid type.
All three cases showed convincing MSH6 expression in
20-40% of tumor cells, although the staining intensity in
one case (case 2) was slightly less than internal control.
(Fig 1) Overall, 98.5% (200/203) of the results from the
2-antibody method were in accordance with the original
4-antibody method.
DISCUSSION
Immunohistochemistry for MMR proteins has
been acknowledged as the most practical screening test
for LS and is performed routinely in many developed
countries. Rates of MMR deciency in endometrial
cancer range from 19.8%- 35%.
4,7,10,12,17,18,20,21
Recently,
Puangsricharoen et al reported MMR deciency in 34.9%
of 166 endometrial cancer cases in ailand.
22
e rate
of MMR deciency in this study is 25.12% which is
lower than a previous ai study. However, population
selection for this retrospective study was based on the
presence or absence of immunohistochemistry for four
MMR proteins and not randomized.
is study supports that IHC testing for only PMS2
and MSH6 is acceptable for initial screening. We found
that PMS2 can detect all cases with loss of both MLH1
and PMS2 and PMS2 alone. While MSH6 can detect
all cases with loss of both MSH2 and MSH6 and MSH6
alone. In fact, the 2-antibody method failed to identify
three cases with an isolate loss of MSH2.
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TABLE 1. Specimen Characteristics (n = 203).
TABLE 2. Mismatch repair protein immunohistochemical staining pattern (n=203).
Characteristic Value
Ageatdiagnosis,average(range),years 45.06(23-62)
Specimen type
Total or subtotal hysterectomy 198 (97.54)
Endometrialsamplingorcurettage 5(2.46)
Tumor cell type
Endometrioidcarcinoma 182(89.66)
Endometrioidcarcinoma-grade1 96(47.29)
Endometrioidcarcinoma-grade2 63(31.03)
Endometrioidcarcinoma-grade3 21(10.34)
Endometrioidcarcinoma-notgraded 2(0.99)
Serous carcinoma 9 (4.43)
Mixedcarcinoma 6(2.96)
Clear cell carcinoma 3 (1.48)
Undifferentiated carcinoma 1 (0.49)
Dedifferentiated carcinoma 1 (0.49)
Carcinosarcoma 1 (0.49)
Immunohistochemicalpattern Number(%)
NolossofnuclearexpressionofMMRproteins 152(74.88)
LossofnuclearexpressionofanyMMRproteins 51(25.12)
LossofnuclearexpressionofMLH1andPMS2 23(11.33)
LossofnuclearexpressionofMSH2andMSH6 13(6.40)
LossofnuclearexpressionofMSH6only 5(2.46)
LossofnuclearexpressionofPMS2only 7(3.45)
LossofnuclearexpressionofMSH2only 3(1.48)
Selected studies on patterns of IHC for 4 MMR
proteins in endometrial cancers were reviewed (Table 3).
Modica et al reported one case of isolate MSH2 loss which
showed MSI-H in MSI testing.
20
Meanwhile, a study by
Crim el al reported one case of isolate MLH1 loss which
is impossible in the 2- antibody method, however, there
was no associated germline mutation.
18
Pearlman et al
also reviewed 1730 colorectal cancer cases with IHC
conducted to screen for LS and reported isolate MSH2
loss in 19 cases; eight had an ambiguous MSH6 expression
Anansitthikorn et al.
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Fig 1. ree cases with an isolate loss of MSH2.
TABLE 3. Literature reports on patterns of immunohistochemical staining for MLH1, MSH2, MSH6 and PMS2 in
endometrial carcinomas
IHCpatterns
Reference Total Lossofanynuclearexpression
MLH1and MSH2and MSH6 PMS2 MLH1 MSH2
Intact PMS2 MSH6 only only only only Others
Modica2007 85 37 23 6 9 6 0 1* 3
(43.53%) (27.06%) (7.06%) (10.59%) (7.06%) (0%) (1.18%) (3.53%)
Garg2009 71 39 19 9 4 0 0 0 0
(54.93%) (26.76%) (12.68%) (5.63%) (0%) (0%) (0%) (0%)
Backes2009 140 110 24 4 2 0 0 0 0
(78.57%) (17.14%) (2.86%) (1.43%) (0%) (0%) (0%) (0%)
Mojtahed2011 40 21 9 4 4 0 0 0 2
(52.50%) (22.50%) (10%) (10%) (0%) (0%) (0%) (5%)
Egoavil2013 173 115 42 5 7 1 0 0 3
(66.47%) (24.28%) (2.89%) (4.05%) (0.58%) (0%) (0%) (1.73%)
LongQ2014 173 132 10 21 7 3 0 0 0
(76.30%) (5.78%) (12.14%) (4.05%) (1.73%) (0%) (0%) (0%)
WatkinsJC2017 242 194 39 4 3 2 0 0 0
(80.17%) (16.12%) (1.65%) (1.24%) (0.83%) (0%) (0%) (0%)
Crim2017 116 92 15 1 3 2 1* 0 2
(79.31%) (12.93%) (0.86%) (2.59%) (1.72%) (0.86%) (0%) (1.72%)
Puangsricharoen 156 99 42 10 5 0 0 0 0
2020 (63.46%) (26.92%) (6.41%) (3.21%) (0%) (0%) (0%) (0%)
Ourstudy2021 203 152 23 13 5 7 0 3* 0
(74.88%) (11.33%) (6.40%) (2.46%) (3.45%) (0%) (1.48) (0%)
*cases in which the 2-antibody method could not detect defects compared to the 4-antibody method
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and 11 had convincing MSH6 expression. Germline
testing of these cases revealed MSH2 mutations in 7/8
cases with ambiguous MSH6 expression and 9/11 cases
with convincing MSH6 expression.
23
In clinical practice,
isolate MSH2 loss is unusual. Genetic consultation and
further investigations, such as MSI testing or germline
testing should be performed. Failure to identify these
rare cases by the 2-antibody method may lead to missed
opportunities for cancer surveillance and carrier testing
in relatives at risk.
IHC interpretation for MMR proteins can be dicult,
especially in cases with focal and weak staining. ere
is still no ocial guideline that provides the cut-o
proportion and staining intensity in tumor cells. us,
discordance results and incorrect interpretation are
possible pitfalls of IHC testing.
CONCLUSION
e results from the 2-antibody method are in
high accordance with the original 4-antibody method.
However, the 2-antibody method fails to detect a few
cases of isolate MSH2 loss which have a potential to
represent those with MSH2 germline mutation.
ACKNOWLEDGEMENTS
e authors thank Assistant professor Suwanit
Therasakvichya and Dr. Pornnapa Lomthong from
Department of Obstetrics and Gynecology, Faculty of
Medicine Siriraj Hospital, Mahidol University for sharing
data and experience.
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adakorn Tantisarasart, M.D.*, Sunisa Chartmongkolchart, M.D.*, Rassamee Chotipanvithayakul, M.D.**
*Department of Anesthesiology, **Department of Epidemiology, Faculty of Medicine, Prince of Songkla University, Hatyai Songkhla 90110 ailand.
Nomogram as a Predictor for Postoperative Acute
Kidney Injury in Super-Elderly Patients Undergoing
Noncardiac Surgery
ABSTRACT
Objective: ere has been increase the incidence of postoperative acute kidney injury (AKI), especially among
super-elderly patients. e study aimed to identify risk factors and develop a nomogram among super-elderly
patients undergoing noncardiac surgery.
Material and Methods: A single-center retrospective cohort study of patients aged greater than or equal to 80
years that underwent non-cardiac surgery between January 2018 to December 2020. Acute kidney injury (AKI) was
identied by Kidney Disease Improving Global Outcome (KDIGO) during seven days aer surgery. Multivariate
logistic regression was constructed from preoperative and intraoperative data with variables with P-value<0.2
included in the nal model. e performance of model function was conducted by area under the receiver curve
(AUC) and calibration curves.
Results: Eight hundred and twenty patients were included; 124 (15%) developed postoperative AKI. A multivariate
logistic regression model consisting of COPD, ASA classication, part of surgery, propofol and Succinylated gelatin
was displayed as the nomogram. e model showed good discrimination with an AUC 0.746. e cuto point of
63, which had the highest Youden index, was chosen with sensitivity and specicity of 83% and 45%, respectively.
e nomogram showed good performance by the Hosmer-Lameshow goodness-of-t test (X
2
= 6.0697 and P value
= 0.6394).
Conclusion: e nomogram predicted model for predicting postoperative AKI among super-elderly patients
showed moderate discrimination ability and was instituted. It can help physicians to detect high-risk patients early
and promptly prevent episodes of AKI.
Keywords: Postoperative acute kidney injury; super-elderly patient; nomogram (Siriraj Med J 2022; 74: 114-125)
Corresponding author: adakorn tantisarasart
E-mail: thadakorn.t@psu.ac.th
Received 1 November 2021 Revised 7 December 2021 Accepted 26 December 2021
ORCID ID: https://orcid.org/0000-0002-2448-3276
http://dx.doi.org/10.33192/Smj.2022.15
INTRODUCTION
Mortality due to surgery and anesthesia has been
reduced from >25% to 19% among elderly aged >80 years.
1
is substantially increased surgery and anesthesia among
them. AKI, a preventable condition, has been one of the
leading cause of post-operative morbidity and mortality
rates, especially among super-elderly patients. e incidence
of acute kidney injury is highest in elderly about 16.98%
2
and increase is age-dependent.
3
erefore, Postoperative
acute kidney injury was associated with 30-day unplanned
readmission, postoperative renal failure, dialysis, risk
of infection and prolonged mechanical ventilation.
4–6
Postoperative AKI is likely related to multifactorial factors
including preoperative factor which is intractable, and
intraoperative and postoperative factors which can be
improved and are preventable.
Tantisarasart et al.
All material is licensed under terms of
the Creative Commons Attribution 4.0
International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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Previous literature has reported that baseline decrease
in eGFR, renal artery involvement, radiocontrast media,
intraoperative hypotension, operative time, surgical
technique, intraoperative crystalloid use, low preoperative
Hemoglobin (Hb), intraoperative blood loss, peripheral
arterial disease, perioperative transfusion, amount of blood
loss, preoperative hypoalbuminemia, general anesthesia
and preoperative use of angiotensin-converting enzyme
inhibitor(ACEI), angiotensin II receptor blockers (ARB)
and diuretics are associated with acute kidney injury .
e most important factors in early detection of high
risk patients include enhanced invasive monitoring,
maintain uid balance and avoid nephrotoxic agent.
8-10
However, there are many predictive tools such
as preoperative GFR, preoperative proteinuria and
preoperative creatinine, but none of these tools are best
validated for prediction of AKI the incidence, risk factor
of postsurgical AKI. Studies documenting predictive score
use in postoperative acute kidney injury among elderly
people are rare. erefore, this study aims to develop a
predicting tool for postoperative acute kidney injury in
super-elderly patients.
MATERIALS AND METHODS
Ethical approval and reporting guidelines
e study was approved by the institutional review
board (IRB) of Prince of Songkla University Hospital (IRB
number: 63-408-8-1). e inform consent was waived due
to the study being observational study without medical
intervention. e study comply with the transparent
reporting of a prediction model for TRIPOD statement.
13
Study hospital and study designs
is retrospective cohort study was conducted in a
tertiary medical center in ailand from 1 January 2018
to 31 December 2020. A total 820 records of all patients
aged ≥80 years who underwent non-cardiac surgery and
received either general anesthesia or spinal anesthesia
were included.
Exclusion criteria were patients who had preoperative
end-stage renal disease requiring renal replacement
therapy, diagnosed acute kidney injury since the time
of admission to a day prior to the surgery, amputee
12
,
bed-ridden, patients without baseline serum creatinine or
follow-up serum creatinine levels to identify postoperative
AKI and no urine output recorded. Eligible patients’ data
were retrieved from anesthetic records in the hospital
information system (HIS) (Fig 1). An anesthesiologist
reviewed patients’ proles and clinical data including ASA
classication, vital signs, and urine outputs. Laboratory
results, details of surgery and anesthesia, and clinical
and hospital-related outcomes were also recorded.
Outcome and denition of acute kidney injury (AKI)
Postoperative AKI was assessed within 7 days aer
surgery. According to Kidney Disease-Improving Global
Outcomes (KDIGO) 2012 guideline
14
, AKI was dened
as either one of the following 3 conditions a) serum
Fig 1. Study ow chart.
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116
creatinine increased by more than 1.5-1.9 times of the
baseline level, b) increase in serum creatinine level more
than 0.3 mg/dL within 48 hours and c) urine output less
than 0.5 mL/kg/h for 6 hours continuously.
e primary outcome was the 7-days AKI rate,
according to KDIGO. Secondary outcomes were post-
operative 30-day mortality rate, period of hospital stay,
period of ICU stay and requirement of renal replacement
therapy.
Sample size determination
Estimated sample size estimated base on ability to
detect association with exposure and outcome at odds
ratio at least 1.5 with 80% power was 820. e statistical
signicance was set at P value ≤ 0.05.
Statistical analysis
Statistical analysis was performed using R program
version 4.0.2.
15
Categorical variables were presented
as percentage and proportion such as gender, Body
mass index (BMI), ASA classication, type of surgery,
choice of anesthesia, part of surgery, and anesthetic
drug use. e categorical parameters were compared
between AKI group and non-AKI group by Student
t-test or Wilcoxon Rank Sum test. In case of small size
population, Chi-squared test or Fisher’ exact test were
used to compare the two groups. Continuous variables
were presented as mean ± standard deviation (SD) and
median ± interquartile range was used to describe normal
and non-normal distribution, respectively. Categorical
variables were analyzed using Chi-square test or Fisher’
Exact test as appropriate.
Predictors of postoperative acute kidney injury
Predictive factors included preoperative and
perioperative data. Pre-operative factors included
patient’s prole, clinical condition, current medication,
and laboratory variables including Hemoglobin and
creatinine. Preoperative serum creatinine level was
analyzed within 24-48 hours prior to surgery. Baseline
creatinine clearance was computed by the standard
Cockcro Gault formula using age, lean body weight
(kg), serum creatinine (mg/dL) and sex. Perioperative
factors included anesthetic drugs, uid resuscitation,
use of vasopressors, estimated blood loss, duration of
surgery, duration of hypotension and intraoperative urine
output and intraoperative hemodynamic. (Supplement 1)
Model development
Variables included in multivariate analysis were
chosen from univariate analysis results that had p-value
< 0.2 (Tables 1 and 2). Multi-collinearity was tested by
using variance ination factor (VIF) > 5 criteria. Stepwise
logistic regression method was used to get the nal model
(Table 3). e Hosmer-Lameshow goodness-of-t test
also displayed a good performance (X
2
= 6.0697 and
P value = 0.6394). e variable with p-value< 0.05 in
multivariate logistic regression model was considered
statistically signicant.
Score derivation and validation
e prediction score variable was selected from
multivariate analysis and weight adjustment was conducted
by nomogram. For the nal model, each predictor score
was summarized in total postoperative acute kidney
injury score. Youden’s index was used to reveal maximize
specicity and sensitivity cuto values of prediction
score.
RESULTS
A total 3840 patients who underwent non cardiac
surgery were assessed for eligibility from 1 January 2018
to 31 December 2020. Eight hundred and twenty eligible
patients were retrieved in this study. e incidence of
postoperative acute kidney injury among super-elderly
was 15%.
Table 1 shows clinical characteristics at preoperative
period between patients with AKI (acute kidney injury)
and non AKI with no statistically signicant dierences
in demographic data such as age, sex, BMI, comorbidities
and preoperative blood pressure among groups. e
mean age of the super elderly was 87 years old and the
average BMI was 21 kg/m
2
. Generally, half of the AKI
group underwent emergency surgery and had a higher
proportion of ASA classication IV and V than non
AKI group. No dierences in part of surgery, choice of
anesthesia and current medication were found between
the two groups. Creatinine clearance among AKI group
was signicant lower than that in the non-AKI group.
Table 2 illustrates clinical characteristics in
intraoperative period between AKI group and non-
AKI group. According to induction agent, midazolam
use was signicantly higher among AKI group, while,
Propofol use tended to lower incidence of AKI compared
to others. Opioid drugs, muscle relaxant drugs and
inhalation agents displayed no signicant dierences
in the postoperative AKI. However, AKI group more
frequently used vasopressors than non-AKI group. e
incidence of postoperative acute kidney injury was higher
among patients with duration of hypotension more than
15 minutes. e AKI group tended to use Succinylated
gelatin for resuscitation more than non AKI group.
Tantisarasart et al.
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Supplement 1. Univariate analysis of risk factors for acute kidney injury.
Variable OR 95%CI P-value
Age* 1.04 (1,1.09) 0.05
Male* 1.24 (0.84,1.82) 0.28
Comorbidities
HT 1.37 (0.9,2.07) 0.13
DM 1.36 (0.85,2.18) 0.19
COPD 1.84 (0.93,3.73) 0.09
PVD 1.12 (0.13,9.7) 0.09
CHF 1.88 (0.19,18.2) 0.58
Type (ref=elective)
Emergency 1.92 (1.3,2.82) <0.05
Part (ref=Neuro)
Abdomen 1.9 (0.92,3.95) 0.08
Orthopedic 2.13 (1,4.55) 0.05
Urology 3.93 (1.48,10.39) <0.05
Vascular 1.91 (0.89,4.11) 0.09
Others 1.77 (0.6,5.2) 0.30
ASA (ref=II)
III 2.19 (1.23,3.9) <0.05
IV-V 13.13 (6.37,27.08) <0.05
CrCl 0.99 (0.97,1) 0.04
Hb 0.93 (0.84,1.02) 0.10
Current medication
ACEI 0.76 (0.38,1.52) 0.43
ARB 0.96 (0.48,1.94) 0.92
Choice (ref=spinal block)
Generalanesthesia 1.02 (0.54,1.89) 0.96
Induction
Propofol* 0.38 (0.25,0.56) <0.05
Etomidate* 2.24 (1.15,4.39) 0.01
Ketamine* 2.44 (0.62,9.57) 0.02
Midazolam* 1.98 (1.34,2.92) <0.05
Narcotic
Morphine* 1.1 (0.31,3.85) 0.88
Fentanyl* 4.96 (0.67,36.83) 0.11
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Supplement 1. Univariate analysis of risk factors for acute kidney injury. (Continue)
Variable OR 95%CI P-value
Muscle relaxant
Cisatracurium* 1.35 (0.67,2.7) 0.39
Roccuronium* 0.78 (0.39,1.56) 0.47
Succinylcholine* 0.94 (0.48,1.83) 0.84
Inhalation (ref=no) 0.09
Sevourane 0.84 (0.5,1.4)
Desurane 0.55 (0.3,1)
Contrastmedia 0.78 (0.47,1.29) 0.33
Hypotension 1.52 (0.97,2.39) 0.06
Durationofhypotension(>=30mins) 2.32 (1.52,3.52) <0.05
Total urine output (ref>=2)
<=0.5 6.87 (3.8,12.42) <0.05
0.51-2 1.81 (1.05,3.12) 0.03
Diureticuse 1.24 (0.65,2.4) 0.51
Vasopressoruse
Norepinephrine* 1.95 (1.33,2.88) <0.05
Ephedrine* 0.59 (0.39,0.89) 0.01
Epinephrine* 4.57 (1.67,12.5) <0.05
Dopamine* 9.58 (3.64,25.23) <0.05
Fluid
NSS* 1.74 (1.11,2.71) 0.01
Balanced salt solution* 0.51 (0.34,0.76) <0.05
Succinylatedgelatinuse* 2.55 (1.66,3.93) <0.05
Blood transfusion 1.65 (1.12,2.42) 0.01
RBC* 1.58 (1.07,2.34) 0.02
FFP* 2.04 (1.25,3.34) <0.05
PC* 2.09 (1.07,4.05) 0.03
Abbreviations: COPD: chronic obstructive lung disease, CHF: chronic heart failure, Hb: hemoglobin, Crcl: creatinine clearance, ACEI:
Angiotensin-converting enzyme inhibitors, ARB: Angiotensin receptor blockers, NSS: normal saline solution, PRC: packed red blood cell,
FFP: fresh frozen plasma, PC: platelet count *Continuous variables
Tantisarasart et al.
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TABLE 1. Clinical characteristics of preoperative period in super-elderly patients with and without Acute Kidney
Injury (AKI) (N=820).
Characteristics AKIgroup Non-AKIgroup P-value
(N=124) (N=696)
N (%) N (%)
Age (years) mean±SD 87.5 ±4.5 86.7±3.9 0.05
Gender 0.32
Female 53 (41.1) 334 (48)
Male 71(57.3) 362(52)
BMI (kg/m
2
)* 21.9(18.9,24.9) 21.7(19.1,24.2) 0.54
Comorbidities
Diabetes 27(21.8) 118(17.0) 0.24
Hypertension 87(70.2) 440(63.5) 0.16
COPD 11 (8.9) 35 (5) 0.13
Congestive heart failure 1 (0.8) 3 (0.4) 0.48
Type of surgery <0.05
Scheduled 59(47.6) 442(63.5)
Emergency 65(52.4) 254(36.5)
ASA type < 0.05
II 15(12.1) 197(28.3)
III 78(62.9) 468(67.2)
IV 28(22.6) 31(4.5)
V 3(2.4) 0(0.0)
PreoperativeHb(g/dL)* 10(9,11.2) 11(9,12) 0.04
PreoperativeCr(mg/dL)* 1.1(0.8,1.4) 0.9(0.8,1.2) <0.05
PreoperativeCrCl(mL/min)* 34.7(26.8,44.9) 38.8(29.6,49.7) <0.05
Part of surgery 0.14
Abdomen 40(32.3) 223(32.0)
Orthopedic 30(24.2) 149(21.4)
Neurology 10(8.1) 106(15.2)
Urology 10(8.1) 27(3.9)
Vascular 28(22.6) 155(22.3)
Others 6(4.8) 36(5.2)
Current medication
ACEI 10(8.1) 72(10.3) 0.53
ARB 10 (8.1) 58 (8.3) 1
Choice of anesthesia 1
Generalanesthesia 111(89.5) 622(89.4)
Spinal block 13 (10.5) 74 (10.6)
Preoperative blood pressure
SBP(mmHg)* 131(115.8,146.2) 130(119,146.2) 0.72
DBP(mmHg)* 69(60,77) 70(62,79) 0.18
MAP(mmHg)* 88.5(81,98.2) 90(82,99) 0.47
Abbreviations: BMI: body mass index, COPD: chronic obstructive lung disease, CHF: chronic heart failure, Hb: hemoglobin, Cr: creatinine,
Crcl: creatinine clearance, ACEI: Angiotensin-converting enzyme inhibitors, ARB: Angiotensin receptor blockers, SBP: systolic blood
pressure, DBP: diastolic blood pressure, MAP: mean arterial pressure *Continuous data were reported as median and IQR 1-3
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TABLE 2. Clinical characteristics of intraoperative period in super-elderly patients with and without Acute Kidney
Injury (AKI) (N=820).
Characteristics AKI Non-AKI P-value
(N=124) (N=696)
N (%) N (%)
Inductionagent
Propofol 73(58.9) 551(79.2) <0.05
Thiopental 0(0) 12(1.9) 0.23
Etomidate 13 (11.5) 35 (5.5) <0.05
Ketamine 3(2.4) 7(1.0) 0.18
Midazolam 57(46) 209(30) <0.05
Narcotic
Morphine 120(97.6) 658(97.8) 0.74
Fentanyl 123(100) 669(99.4) 1
Muscle relaxant
Succinylcholine 11 (10.3) 67 (10.9) 0.98
Cisatracurium 97 (90.7) 539 (87.8) 0.49
Rocuronium 10(9.3) 72(11.7) 0.58
Inhalation
Sevourane 72(58.1) 371(53.3) 0.37
Desurane 29(23.4) 226(32.5) 0.05
No 23(18.5) 99(14.2) 0.26
Vasopressor
Ephedrine 38(30.6) 298(42.8) 0.01
Epinephrine 7 (5.6) 9 (1.3) <0.05
Norepinephrine 71(57.3) 283(40.7) <0.05
Durationofsurgery(minutes)mean±SD 177.5(135,256.3) 180(135,256.2) 0.88
Intraoperativehypotension 96(77.4) 482(69.3) 0.08
Durationofhypotension(minutes)* 15(5,82.5) 10(0,20) <0.05
Contrastmediause 21(16.9) 144(20.7) 0.39
Diureticuse 12(9.7) 55(7.9) 0.63
Fluidintake(mL)* 1150(500,2000) 1100(700,1675) 0.63
Balanced salt solution (mL)* 1000 (500, 1450) 1000 (700, 1500) 0.56
NSS(mL)* 500(100,1212.5) 500(0,1000) 0.07
Succinylatedgelatin* 500(450,675) 500(300,500) 0.02
Blood transfusion 0.01
PRC 54(43.5) 228(32.8) 0.02
FFP 26(21) 80(11.5) <0.05
PC 13 (10.5) 37 (5.3) 0.04
Intraoperativebloodloss(mL)* 150(50,412.5) 100(50,300) 0.06
Intraoperativeurineoutput(mL/kg/hr) <0.05
≤0.5 46(37.1) 80(11.5)
0.51-2 59(47.6) 389(55.9)
>2 19(15.3) 227(32.6)
Abbreviations: NSS: normal saline solution, PRC: packed red blood cell, FFP: fresh frozen plasma, PC: platelet count *Continuous data
were reported as median and IQR 1-3
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Nonetheless, Blood transfusion consists of red blood
cells, fresh frozen plasma and platelet concentrate that
were used in AKI group more than others. Intraoperative
urine output less than 5 mL/kg occurred in 75% of AKI
group, while an intraoperative output less than 5 mL/kg
were found a higher risk in AKI group than non-AKI
group (P-value<0.05). Other independent variables were
not statistically dierent.
Table 3 presents multivariate logistic regression model
adjusted for patient’s status and anesthetic drug. Independent
variables signicantly associated with postoperative AKI
were COPD, ASA classication, part of surgery, Propofol
and Succinylated gelatin. ere was greater frequency of
AKI with higher ASA classication with ASA III and ASA
IV with V [OR 2.58 (1.41,4.73), OR 13.73 (5.94,31.76),
P-value <0.05], respectively. Part of surgery diered
signicantly between AKI and non-AKI group (P-value
<0.05). e risk of AKI was associated with abdominal
surgery, orthopedic surgery and urology surgery [OR
2.85 (1.27,6.38), OR 3.22(1.4,7.4), OR 8.31(2.86,24.12)],
respectively, excluding patients that underwent vascular
surgery. In contrast, Propofol conserved renal function
[OR 1.95 (1.21,3.16), P-value<0.05]. ere was a statistically
signicant risk for AKI with Succinylated gelatin use
[(OR 1.94(1.2,3.14), P-value <0.05)].
e nomogram comprised of COPD, ASA classication,
Part of surgery, Type of surgery, Propofol and Succinylated
gelatin (Fig 2). e score ranged from 20 to 100. e
nomogram has a good discriminative ability to identify
patients with postoperative AKI with AUC 0.746. e
calibrate curve shows that the apparent value is almost
the same as bias-corrected value; mean squared error
= 0.00043 (Fig 3). Cuto point at 63 was chosen, which
had the highest Youden index. e sensitivity, specicity,
positive predictive value (PPV) and negative predictive
value (NPV) of the prediction score was 83, 45, 33, and
89%, respectively.
e rate of renal replacement was higher in patients
with postoperative AKI compared with patients without
AKI (P-value<0.05). Period of ICU stay and hospital
stay was signicantly longer in AKI group than other
groups (P-value<0.05). Furthermore, 30-day mortality
was signicantly greater in AKI group (P-value <0.05).
TABLE 3. Best predictive score revealed by multivariate logistic regression.
Riskfactor Ref CrudeOR(95%CI) Adj.OR(95%CI) P(LR-test) RiskScore
COPD No 1.84(0.91,3..73) 2.02(0.93,4.38) 0.07 24
Type Scheduled
Emergency 1.92(1.3,2.82) 1.43(0.89,2.31) 0.14 14
ASA
II <0.05
III 2.19(1.23,3.9) 2.58(1.41,4.73) 37
IV-V 13.13(6.37,27.08) 13.73(5.94,31.76) 100
Part of surgery Neuro <0.05
Abdomen 1.9(0.92,3.95) 2.85(1.27,6.38) <0.05 42
Orthopedic 2.13(1,4.55) 3.22(1.4,7.4) <0.05 48
Urology 3.93(1.48,10.39) 8.31(2.86,24.12) <0.05 90
Vascular 1.91(0.89,4.11) 1.8(0.78,4.12) 0.16 25
Others 1.77(0.6,5.2) 2.35(0.73,7.57) 0.15 35
Propofol Yes 2.65(1.78,3.97) 1.63(1,2.66) <0.05 19
Succinylatedgelatin no 2.55(1.66,3.93) 1.94(1.2,3.14) <0.05 26
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122
Fig 2. e nomogram explicated by logistic regression. Each predictor variable is presented by a line in the gure. e prediction scores
ranged from 0 to 100. e variables were gathered with point and paired with the probability of postoperative AKI. A drawing from was
made from each variable to the “Points” axis to indicate the points of the variable. e scores for all variables were summed and placed on
the “Total score” line. e predicted risk of postoperative AKI ranged from 5 to 80%.
Fig 3. e AKI nomogram and its performance. e Apparent value has a closer t to Bias-corrected value, which means the nomogram
had a good performance. Mean absolute error=0.014 Mean squared error=0.00036 Quantile of absolute error=0.03.
Tantisarasart et al.
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DISCUSSION
Nowadays, there is no eective equipment to identify
the probability of postoperative AKI in surgical patients,
particularly in super-elderly patients. AKI is a serious
consequence aer surgery. A prior study demonstrated
that approximately 6.8% of patients undergoing abdominal
surgery developed an episode of AKI.
16
In the present
study, almost 15% of AKI among super-elderly and
24.2% with AKI died in 30 days. e incidence of acute
kidney injury is highest in elderly and increases with
age.
3,17
ere are many reasons for the comparatively high
probability of AKI in super elderly patients, for instance,
comorbidities that produce AKI, comorbidities that
need intervention, medication or surgery that disarrange
kidney function, and structure and function that alter
with time.
3,9
According to meta-analysis, elderly patients
fail to recover from AKI and develop to chronic kidney
disease.
18
e risk of postoperative acute kidney injury is
associated with patient factors as age, type of surgery,
emergency surgery, part of surgery, ASA classication,
preoperative hemoglobin (Hb), preoperative creatinine,
preoperative creatinine clearance, and medical comorbidities
such as chronic obstructive lung disease (COPD). It is
not surprising that emergency surgery was found as a
part of the AKI prediction score, as in this study. A US
national study revealed that not only cardiac surgery, but
also urology, thoracic, orthopedic and malignancy were
associated with AKI.
19
In patients following non-cardiac
surgery, ASA classication III and IV were shown to
comprise a higher proportion of AKI than those with
ASA classication I and II.
4
Other preoperative laboratory data, preoperative
anemia
7
high creatinine
20
, low creatinine clearance
6
and
low eGFR
2
were shown to be similar with previous studies.
In cardiac surgery, preoperative anemia increased AKI
rate from 1.8% to 3.2%. Meanwhile, patients receiving
blood transfusion had relative risk of AKI more than two
times compared without transfusion.
21,22
e mechanism
of blood transfusion that could cause AKI is still unclear.
Although, It was suggested that pathophysiology can
aggravate tissue oxygen delivery and stimulate inammatory
process and oxidative stress.
23-25
Previous study showed
that higher baseline preoperative creatinine was signicant
risk factor for AKI.
26
Apart from urine output, Mizota T
et al. found perioperative urine output less than 0.3 mL/
kg/h increased probability of AKI.
27
Even if perioperative
urine output was dened dierently, the result remains
the same.
Neither the univariate analysis nor the nomogram
of the study found a signicant dierence with diuretic
use, which is a known AKI stimulator. It is probably due
to the reason that we are not given in lower creatinine
clearance patient. Nonetheless, The use of diuretic,
particularly furosemide has been demonstrated deleterious
in prevention and treatment of AKI.
28,29
In this study, the use of norepinephrine and
epinephrine was essential factor. Norepinephrine, is
frequently used to restore MAP from 60 to 75 mmHg
and increase renal oxygen delivery (RDO
2
), Glomerular
ltration rate (GFR) and renal oxygenation.
30
On the
other hand, It has been shown that norepinephrine
decreases renal blood flow (RBF) and renal oxygen
delivery, which provoke renal ischemia.
31
Epinephrine
has the same ecacy as norepinephrine, but also causes
hyperglycemia, hyperlactatemia and acidosis.
31
Based
on current evidence, norepinephrine should be used
to restore blood pressure within autoregulatory values
TABLE 4. Postoperative consequence in patients with and without Acute Kidney Injury (AKI).
Characteristics AKI Non-AKI P-value
(N=124) (N=696)
Renalreplacementn(%) 15(12.1) 1(0.1) <0.05
PeriodofICUstay(days)* 2.5(0,12) 0(0,1) <0.05
Periodofhospital(days)* 14.5(8.8,28) 10(7,18)
Death30n(%) 30(24.2) 11(1.6) <0.05
*Continuous data were reported as median and IQR 1-3
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124
in hypotensive vasodilated patients with acute kidney
injury.
31
According to previous knowledge, propofol is
down regulated by nitric oxidase synthase to preserve
renal function
32
and protect renal tissue via peroxidation
of lipid membrane.
33
Lee et al. reported that propofol
reduced the new onset of chronic kidney disease aer
nephrectomy.
34
erefore, the anti-inammatory eect
of propofol might be signicant in the use of TIVA
technique, whereas propofol in this study was used as
a sole induction agent.
Resuscitation uid, such as Succinylated gelatin
another factor which impacts postoperative acute kidney
injury. Recent guidelines suggest avoiding the use of
gelatin, as systemic colloids gather in proximal renal
tubules and disturb renal function, increasing the risk
of anaphylaxis, mortality, renal failure and bleeding.
35
AKI Predictor in surgical super-elderly patients
consist of baseline characteristics and perioperative data.
We have found a relationship AKI: COPD, type of surgery,
ASA classication, part of surgery and Succinylated
gelatin. Propofol was used as a defensive factor in this
study. Prior study on AKI prediction score in a dierent
setting, displayed a good discrimination which AUC
range above 0.7. For instance, for the eGFRpreSurg as
a predictive role among very elderly patients, AUC was
at 0.703.
2
is represented eGFRpreSurg at cut o point
70mL/min/1.73 m
2
as a risk factor of postoperative AKI.
Another study by Hong et al. reported the relationship
between HUGE formula and mortality in elderly patients
from hip fracture surgery with highest AUC of 0.78
(95%CI 0.667-0.892).
26
However, both of the predictors
were in super-elderly patient settings and the score
obtained from only preoperative data.
is nomogram score in the study is easily understood
and handly to adopt in preoperative period. Accordingly,
AKI is a preventable condition, nomogram may help
physicians to early detect AKI and handle it in proper
time. According to resource-limited countries such
as ailand, invasive monitoring in every case might
be impossible. e most eective prevention is early
detection in high risk, special monitoring, optimal uid
administration and nephrotoxic agent avoidance. From
the research principle, it is expected that the nomogram
will eectively assist in selection high risk AKI patients
for prevention and aggressive intervention.
Strength and limitation
e incidence of AKI might be precise because AKI
in this study was determined by both urine output and
serum creatinine. e result may be in indubitable in
the occurrence of AKI.
ere are some limitations of this study. Firstly,
although all super-elderly patients who underwent surgery
in the study period were retrieved to reduce selection
bias, patient bias was unavoidable due to retrospective
study. Secondly, this study could not analyze the cause
of AKI categorized into three groups: prerenal, renal and
postrenal due to lack of information in our electronic
hospital system. e rate of renal replacement therapy
was compared between AKI and non-AKI patients;
nonetheless there was a lack of information to identify
the reason for renal replacement therapy.
Finally, due to the lack of external validation of the
scoring system since this is a single center study and
there could have been sampling bias. Future studies
performed on the scoring system using data of multiple
centers can validate it.
CONCLUSION
is study found an increase incidence of postoperative
AKI among super-elderly patients and relationship
between AKI and morbidity and mortality. Despite, AKI
prediction score not being a denitive tool for observation
and monitoring, it can help physicians consider various
clinical risk factors in evaluating the chance of AKI.
is nomogram can help clinical physicians improve
the prognosis among super-elderly patients undergoing
surgery.
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Hathaichanok Suesat, M.D.*, Varalak Srinonprasert, M.D.**, ***, Panita Limpawattana, M.D.****, Salinee
Nakyos, M.D.*****, Jiraporn Poontananggul, M.D.*, Chalita Jiraphorncharas, B.S.***, Wiraphon Manatarinat,
M.D.******, anachai Noomprom, B.S.******,
Arunotai Siriussawakul, M.D.*, ***
*Department of Anesthesiology, **Division of Geriatric Medicine, Department of Medicine, ***Siriraj Integrated Perioperative Geriatric Excellent
Research Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, ailand, ****Division of Geriatric Medicine, Department
of Internal Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, ailand, *****Division of Anesthesiology, Buddhachinaraj
Hospital, Phitsanulok 65000, ailand,******Siriraj Center of Telemedicine (SiTEL), Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok
10700, ailand
Detection of Postoperative Cognitive Dysfunction by
Telemedicine Among Octogenarian Patients Who
Underwent Minor Elective Surgery; Prospective
Cohort Study
ABSTRACT
Objective: Postoperative cognitive dysfunction (POCD) is associated with permanent disability, increased mortality,
and diminished quality of life. e incidence of acute POCD among geriatric patients who have undergone minor
surgery is uncertain because they are typically discharged before acute POCD is detected. Owing to the ecient
postoperative care that can be provided, telemedicine is an attractive tool to investigate POCD. e primary
objective of our research was to explore the incidence of acute POCD, while its secondary objective was to describe
the consequences of POCD on functional recovery and quality of life.
Materials and Methods: is prospective cohort study enrolled patients aged ≥ 80 years and scheduled for
minor elective surgery. During pre-anesthetic visits, we installed a telecommunications program on the patients’
smartphones. Assessments of cognitive and other functions were performed preoperatively and 1 week postoperatively
via telemedicine.
Results: Forty octogenarian patients undergoing minor surgery were included in the nal analysis. e acute-
POCD incidence was 10% (95% CI 4.79-18.39). Recall memory was the main cognitive domain impaired aer the
procedures. Nevertheless, there were no signicant dierences in the functional recovery and quality of life of the
POCD and non-POCD patients.
Conclusion: e acute-POCD patients demonstrated minor symptoms that were unrelated to delayed postoperative
functional recovery or decreased quality of life.
Keywords: Anesthesia; geriatrics; postoperative cognitive dysfunction; RUDAS-ai; telemedicine. (Siriraj Med J
2022; 74: 126-133)
Corresponding author: Arunotai Siriussawakul
E-mail: arunotai.sir@mahidol.ac.th
Received 12 December 2021 Revised 9 January 2022 Accepted 13 January 2022
ORCID ID: https://orcid.org/0000-0003-0848-6546
http://dx.doi.org/10.33192/Smj.2022.16
Suesat et al.
All material is licensed under terms of
the Creative Commons Attribution 4.0
International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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INTRODUCTION
Multiple comorbid conditions are typical in the
elderly, resulting in an increased possibility of surgical
intervention and anesthesia.
1
Postoperative cognitive
dysfunction (POCD), defined as an impairment of
cognitive function arising aer surgery, frequently occurs
among elderly patients.
2
e systemic stress response
arising during surgical procedures includes changes
in the brain function and is involved in a decline in
cognitive function.
3
Factors that elevate the risk of POCD
include increasing age, pre-existing cerebrovascular and
cardiovascular disorders, a history of alcohol abuse, and
a low educational level.
4
Perioperative hypoxemia and
hypotension, postoperative infection, and respiratory
complications are some of the recognized risk factors
for POCD.
5
POCD is associated with poorer recovery,
an increased risk of permanent disability, and the need
to utilize social nancial assistance.
4,6
POCD can be divided into acute, intermediate, and
long-term changes. “Acute POCD” is used to describe
cognitive declines detected within 1 week of surgery,
“intermediate POCD” for changes occurring within 3
months, and “long-term POCD” for declines persisting
up to 1-2 years following surgery. However, the exact
signicance of detecting POCD at these various time
points is unclear.
7
POCD was found to be present in
25.8% of patients 1 week aer non-cardiac surgery and
in 9.9% aer 3 months.
5
Other research on patients aged
≥ 60 years who had undergone minor surgery established
that their POCD incidence was 6.8% at 1 week and 6.6%
at 3 months.
8
e symptoms of acute POCD may be subtle and might
be dicult to detect among geriatric patients who have
undergone minor surgery. Patients are oen discharged
before any symptoms occur. Neuropsychological testing is
required to detect POCD by comparing preoperative and
postoperative scores.
4
e Rowland Universal Dementia
Assessment Scale (RUDAS) is a short, cognitive-screening
instrument designed to minimize the eects of cultural
learning and language diversity on the assessment of
baseline cognitive performance. e ai version of
RUDAS can be utilized for assessments conducted via
telemedicine. Telemedicine facilitates the post-discharge
monitoring of remotely delivered health care in a cost- and
time-saving manner.
9,10
e primary objective of this study
was to establish the incidence of acute POCD detected
via telemedicine among octogenarian patients who had
undergone minor surgery. e secondary objective was to
describe the consequences of POCD on their functional
recovery and quality of life.
MATERIALS AND METHODS
Study design and participants
e study was approved by the Siriraj Institutional
Review Board, Faculty of Medicine Siriraj Hospital,
Mahidol University, Bangkok, ailand (protocol approval
number Si. 168/2018) and was registered in the ai
Clinical Trials Registry (TCTR) under study number
TCTR20201216001 date registered on December 16, 2020.
Retrospectively registered. Written informed consent
was obtained from all study participants. A prospective
study was conducted at a large university-based national
tertiary referral center during the July 2018 to April 2019
study period. e inclusion criteria were patients aged
≥ 80 years who were scheduled for minor elective surgery.
Such surgery had an expected blood loss of < 500 ml,
no signicant uid shi, and no need for complex post-
operative care typically done on an ambulatory basis
(breast surgery without reconstruction; laparoscopic
cholecystectomy; hernia repair; most cutaneous, supercial,
so tissue excision; and endoscopic procedures such as
ERCP, bladder, and ureteric surgery).
11
Patients or their
caregivers needed to use smartphone support provided by
way of the “Polycom RealPresence Mobile” application.
Patients were excluded if they had factors that might
aect the execution of remote cognitive assessments,
such as an inability to understand the ai language, a
severe visual or auditory dysfunction, an unstable mental
status, or being bedridden. Patients reluctant to complete
the preoperative and postoperative RUDAS-ai test
were also excluded. e study protocol followed the
guidelines of the Declaration of Helsinki and all of its
later amendments.
e day before surgery, a sta member installed the
RealPresence Mobile application on the smartphones of
the patients or their primary caregivers, who were then
trained in its usage. e caregivers helped the patients
to establish the connection. However, they did not have
any active role during the interview or examination.
e mobile application enabled high-quality audio and
video communications to be had during preoperative
and postoperative assessments. Audio-visual data were
shared and transferred via a real-time video stream over
a 3G or 4G mobile phone network, with the intermediary
Internet Service Provider providing the soware interface
between the applications held by the hospital-based
physicians and the patients. Fig 1 illustrates the broad
process of collecting data for telemedicine purposes using
a technological network. e tests for each patient were
performed in about 30 minutes. ey were conducted
by a psychologist who was trained to communicate
with patients by oral and visual questioning based on a
questionnaire.
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128
Assessments
e RUDAS-ai version was applied to assess
cognitive functions preoperatively. The 6 cognitive
domains that RUDAS assesses are memory, praxis,
language, judgment, drawing, and body orientation.
12
e maximum total score is 30. In elderly patients with
a pre-elementary education level, preoperative cognitive
impairment was suspected if the total score was ≤ 23 (AUC
= 0.79; sensitivity and specicity of 71.43% and 76.92,
respectively), while in the case of elderly patients with a
post-elementary education, a score of ≤ 24 (AUC = 0.8,
sensitivity and specicity of 77% and 70%, respectively)
was considered the threshold. e RUDAS-ai can be
an eective alternative test and can be utilized instead
of the Mini-Mental State Examination (MMSE) for
dementia screening.
13
e present study therefore used
the RUDAS-ai to detect POCD. Acute POCD, detected
within 1 week post-operatively, was diagnosed if a score
had decreased by ≥ 3 compared with its pre-operative
level.
14,15
Several other tests were carried out to comprehensively
assess potentially aected aspects. e Barthel Activities of
Daily Living index was used to measure activity limitations
in the domains of personal care and mobility.
16
e
5-level EQ-5D questionnaire was administered to assess
quality of life.
17
Montgomery–Asberg Depression Rating
Scale testing was conducted to establish the severity of
depressive symptoms.
18
Finally, a numeric rating scale
was utilized to evaluate postoperative pain levels, while a
verbal rating scale was employed to identify the degrees
of postoperative nausea and vomiting.
Statistical analysis
e sample size calculation was based on a study
by Canet et al., which found a POCD incidence of 6.8%.
8
erefore, 43 patients were needed for the rare-event analysis
in this study. (nQuery Advisor version 7.0; Statistical
Solutions Ltd., Cork, Ireland).
19
Once an estimated 10%
loss to follow-up was added, the number of participants
required was determined to be 48.
e demographic data and clinical variables were
summarized using descriptive statistics. e continuous
data were reported as means and standard deviations, or
as medians with minima and maxima, as appropriate.
e categorical data were reported as frequencies and
percentages. e statistical analyses were calculated
using SPSS Statistics for Windows (version 18; SPSS Inc.,
Chicago, Ill., USA). A p-value of < 0.05 was considered
statistically signicant.
RESULTS
Fiy-six octogenarian patients were recruited for the
study (Fig 2). Of those, sixteen (28%) were subsequently
withdrawn due to surgery postponement, loss to follow-up,
Fig 1. e technological network of data collection with telemedicine
in health care service.
Suesat et al.
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129
Original Article
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or incomplete postoperative data collection resulting from
patient inconvenience or technical issues (application
errors and internet-signal problems). e data relating
to 40 patients were therefore included in the final
analysis. e number of patients needed for the study was
re-calculated, based on the actual probability of event (π)
with a 95% condence interval (CI), to conrm that a
sample size of 30 cases was adequate for the achievement
of the primary objective.
e characteristics of the octogenarian patients
who underwent minor elective surgery and anesthetic
management are detailed in Table 1. e mean preoperative
RUDAS score, Barthel Index score, EQ-5D-5L score,
and MARDS score were 23.40, 17.38, 0.860, and 2.45,
respectively. Four octogenarian patients were diagnosed
with acute POCD during postoperative Days 5-9, giving
an incidence of acute POCD of 10% (95% CI 4.8-18.4).
e characteristics of those patients are summarized in
Table 2. All four had graduated from primary school,
and hypertension was one of their coexisting diseases.
Impairment in recall memory was found with each
POCD patient. One patient received benzodiazepine to
achieve adequate sedation before surgery. Two patients
experienced intraoperative adverse events (bradycardia
or hypotension) requiring fluid resuscitation and a
vasopressor.
ere were no dierences in the functional declines,
decreases in the quality of life, or levels of depression
of the POCD and non-POCD patients (Table 3). About
3 days aer surgery, the incidence of POCD patients
who had experienced mild-to-moderate pain was 7.5%
(95% CI 3.45-15.76). e median (range) pain score for
the numeric rating scale was 0 (0, 6). Only one of the
40 octogenarian patients had a mild severity of nausea
and vomiting, occurring on the rst day aer anesthesia;
consequently, the overall incidence of postoperative
nausea and vomiting was 2.5% (95% CI 0.61-8.76).
DISCUSSION
e incidence of acute POCD in this study was 10%.
is was higher than the gure reported by a previous
study, which revealed that the POCD incidence among
patients aged ≥ 60 years and undergoing minor surgery
was 6.8% (95% CI 4.3–10.1).
8
Increasing age signicantly
elevates the incidence of POCD because, relative to
younger age groups, individuals with advanced age more
frequently have physical and mental frailty as well as a
decreased ability to cope with stresses, such as anesthesia
and surgery.
2
Yon et al, reported that anesthesia-induced
apoptotic neuro-degeneration might also be a potential
pathway mediating the development of POCD in the
older brain.
20
Glumac et al. showed that preoperative
dexamethasone administration may ameliorate the
incidence of early POCD aer cardiac surgery. is
may be because the inammatory response to surgical
procedure is a key factor in the development of POCD.
21
All 4 POCD patients had impaired recall memory
performance. A deterioration of the memory functions
is one of the most consistently reported complaints by
the elderly.
22
Work by Philp et al. demonstrated that
the associations between thalamic structure, integrity,
and higher-order cognitive processes-including the
Fig 2. Flowchart of study design.
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130
TABLE 1. Patient characteristics, type of surgical procedures, and anesthetic management.
Variables n=40
Age(years) 84.20±3.6
Gender
Female 20
Male 20
Education levels
Pre-elementary 29(72.5)
Post-elementary 11(27.5)
Monthly income (Thai baht)
≤20,000 12(30.0)
>20,000 28(70.0)
Marital Status
Married 17(42.5)
Widowed 23(57.5)
Type of surgery
Urologicalendoscopicsurgery 20(50)
Laparoscopic surgery 7 (17.5)
Breast surgery 4 (10.0)
Endoscopic retrograde cholangiopancreatography 4 (10.0)
Wound debridement 3 (7.5)
Anesthetic technique
Generalanesthesia 23(57.5)
Spinalanesthesia 11(27.5)
Deep sedation 6 (15.0)
Preoperative Scores
TheRowlandUniversalDementiaAssessmentScale 23.40±5.00
The Barthel Activities of Daily Living index 17.38 ± 3.41
The 5-level EQ-5D 0.860 ± 0.188
TheMontgomery–AsbergDepressionRatingScale 2.45±3.60
Intraoperative benzodiazepine administration 4 (10.0)
Intraoperative adverse events
Hypotension 19 (47.5)
Bradycardia 2(5.0)
Hypertension 2(5.0)
Values expressed as the mean ± SD or n (%).
Suesat et al.
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component processes of memory and the executive
functions of attention and information processing-
typically decline with age.
23
erefore, reductions in the
functional connectivity to the thalamus may contribute
to age-related cognitive decline.
24
is may explain why
most of the cognitive-domain eects in our study were
related to recall memory.
POCD is associated with functional dependence and a
poor quality of life.
21,25
Previous research has demonstrated
that even the early stages of cognitive impairment adversely
aect the quality of life.
26
In contrast, our research found
that there was no signicant development of functional
dependence or lowering of the quality of life of the
acute-POCD patients. is suggests that minor elective
surgery, ambulatory surgery, and anesthesia are quite
suitable for octogenarian patients. Depression is also one
of the most common illnesses in the elderly population.
27
Steinmetz et al. found that the occurrence of depression
was not associated with the incidence of POCD at 1
week.
28
Likewise, we found that there was no signicant
development of depression among the POCD patients.
Improvements to the population’s health literacy
has the potential to allow individuals to access health
services, to understand basic health-related information,
TABLE 2. Characteristics of the POCD patients.
Cognitive domain
Case
Age Gender Education Coexisting BDZ Operation Anesthetic Intraoperative impairments
no. diseases technique
adverse events
Recall Drawing
Language
memory
1. 80 Male Primary HT,DLP, No Urological SA Bradycardia √ √ √
school DM endoscopy
2. 82 Male Primary HT,DLP, No Urological GA No √ √
school CVA endoscopy
3. 83 Female Primary HT, DM No
Debridement
GA Hypotension √ √
school
4. 85 Female Primary HT,IHD, Yes ERCP Deep No √ √
school DLP, CVA sedation
Abbreviations: BDZ: Benzodiazepine, CVA: cerebrovascular accident, DLP: dyslipidemia, DM: diabetic mellitus, ERCP: endoscopic
retrograde cholangiopancreatography, GA: general anesthesia, HT: hypertension, IHD: ischemic heart disease, SA: spinal anesthesia
TABLE 3. Comparison of the postoperative functional recovery, depression, and quality of life of the POCD and
non-POCD patients.
Variables
POCD Non-POCD
(n=4) (n=36)
p-value
Functionaldecline 2(16.7) 10(83.3) 0.35
Depression 1 (6.7) 14 (93.3) 0.58
Decreasedqualityoflife 2(13.3) 13(86.7) 0.58
Values expressed as the n (%).
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132
to communicate their health statuses well enough, and
to make appropriate health decisions.
29
In other words,
adequate health literacy is key to patients’ abilities to
maintain their health, achieve behavioral change, and
eectively utilize medical services.
30
eHealth requires
the use of everyday technology, such as telephones,
computers, and services available through the Internet;
unfortunately, this can prove to be very challenging for
elderly patients.
31
Our study found that many of the
octogenarian patients had limited experience with new
technological devices, and their eHealth literacy skills
were low. e assistance of their caregivers was therefore
vital in allowing them to communicate eectively via the
application. It follows that the provision of basic training
in communications technology and the use of a less
complex eHealth application are needed to signicantly
improve the eHealth literacy of the older population.
ere were several limitations of our study. Firstly, the
anesthetic techniques and surgical procedures employed
were varied. Although all of the procedures were categorized
as minor surgery, further research should be considered
to assess the impact of technique variations on POCD,
such as the use of moderate sedation, deep sedation,
and general anesthesia. Secondly, data collection was
interrupted on occasion by technological hindrances,
such as internet-signal loss and the application not
being suciently user-friendly for the elderly. Sixteen
participants were therefore terminated from our study
due to their inability to complete the postoperative
cognitive tests. Lastly, the sample size was too small to
identify the risk factors for acute POCD in the elderly
ai population. Future studies are recommended to
establish those risk factors and to discover means of
preventing POCD onset.
In summary, the incidence of early POCD aer minor
surgery in octogenarian ai patients was higher than the
gure reported by previous research, most probably due
to the present study focusing on a much older population.
e acute POCD revealed by the current work was not
related to a delayed postoperative functional recovery
or a poor quality of life. Hence, it can be concluded that
minor elective surgery and anesthesia are quite suitable
for octogenarian patients.
ACKNOWLEDGEMENTS
This study was supported by a grant from the
Faculty of Medicine Siriraj Hospital, Mahidol University,
Bangkok, ailand (IO R016131035). e funding bodies
had no role in the design of the study; the collection,
analysis, and interpretation of data; or the writing of the
manuscript. e authors acknowledge Mrs. Nipaporn
Sangarunakul, BNS, Ms. Sunit Jarungjitaree, and Ms.
Chayanan anakiattiwibun MSc, the Siriraj Integrated
Perioperative Geriatric Excellent Research Center, Faculty
of Medicine Siriraj Hospital, Mahidol University, Bangkok,
ailand, to provide support for research.
Potential conicts of interest
e authors declare that there are no conicts of interest.
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Valeerat Swatesutipun, M.D., Teerayut Tangpaitoon, M.D.
Division of Urology, ammasat University Hospital, Pathumthani 12120, ailand.
The Prevalence and Risk Factors of Storage Urinary
Symptoms in Symptomatic COVID-19 Patients Who
were Treated in Cohort Ward and Field Hospital
ABSTRACT
Objective: e primary aim of this study was to focus on the prevalence of storage symptoms in COVID-19 patients
and the factors associated with those symptoms.
Material and Methods: We collected the data of COVID-19 patients who were admitted to the cohort ward, ICU
and eld hospital of ammasat University Hospital, ailand, between May and June 2021. Patients answered
online survey questions and undertook urinalysis by urine dipstick test. e online survey questions related to
symptoms of COVID-19 infection, number of daytime voiding, nocturia, frequency and urgency symptom during
COVID-19 infection, OABSS and ICIQ-LUTS in the part of storage symptoms subscale.
Result: ere were 136 COVID-19 patients who met with the eligible criteria and were willing to participate in
the study. Patients who had storage symptoms totaled 61 (44.85%) and had average daytime frequency, nocturia
and proportion of urgency higher than no storage symptom group (5.9 VS 3.8, 2.0 VS 1.0 and 67.21% VS 6.67%
(p-value <0.001), respectively). e OABSS and ICIQ storage subscale in the storage symptoms group were higher
than normal group, 3.2 VS 0.9 and 4.5 VS 1.7 (p-value < 0.001), respectively.
Conclusion: Our study demonstrated that the SARS-CoV-2 virus infection is associated with abnormal storage
symptoms which include frequency, urgency and nocturia. e storage symptoms may be associated with the
severity of COVID-19 disease.
Keywords: Storage symptoms; COVID-19; SARS-CoV-2 virus; viral cystitis (Siriraj Med J 2022; 74: 134-141)
Corresponding author: Teerayut Tangpaitoon
E-mail: jojoteerayut@gmail.com
Received 15 November 2021 Revised 7 January 2022 Accepted 13 January 2022
ORCID ID: https://orcid.org/ 0000-0001-7408-1876
http://dx.doi.org/10.33192/Smj.2022.17
INTRODUCTION
Since the pandemic of the Severe Acute Respiratory
Syndrome Coronavirus-2 (SARS-CoV-2) or Coronavirus
Disease 2019 (COVID-19) has spread around the world
in 2019, the outbreak is still ongoing with no end in
sight. e main infected organ is the respiratory tract
1,2
;
however, the SARS-CoV-2 virus can also infect the
urinary tract, especially the bladder. Previous studies
have reported that SARS-CoV-2 virus could be isolated
from a urine sample.
3
Patients who were infected had a
high prevalence of abnormal urinary storage symptoms;
urinary frequency, urgency and urinary incontinence.
4,5
Moreover, the severity of urinary storage symptoms
and the presence of hematuria and proteinuria from
urinalysis is related to the severity of COVID-19 disease
and mortality rate.
6
In ailand, the high rate of outbreak
occurred during the second, third and fourth wave. e
second wave was caused by the SARS-CoV-2 strain GH,
Swatesutipun et al.
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the Creative Commons Attribution 4.0
International (CC-BY-NC-ND 4.0)
license unless otherwise stated.
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the third wave by the SARS-CoV-2 strain B1.1.7 (alpha
strain) and the fourth wave by the SARS-CoV-2 strain
B.1.617 (delta strain). e intensive care requirement
and the mortality rate of the third and fourth waves were
signicantly higher than those of the second wave. e
primary aim of this study was to focus on the prevalence
of storage symptoms in COVID-19 patients and the
factors associated with those symptoms. Another aim of
our study was to study the abnormal urinalysis related
to the severity of COVID-19 infection.
MATERIAL AND METHODS
is study was cross-sectional. We collected the
data of COVID-19 patients, aged between 18 to 60
years old, who were admitted to the cohort ward, ICU
and eld hospital of ammasat University Hospital,
Pathumthani, ailand, between May and June 2021.
Inclusion was restricted to COVID-19 patients who
could use smartphones to respond to our online survey
questions. Patients who had clinical presentation of
suspicious bacterial cystitis (had dysuria or urine dipstick
test positive for nitrite or leukocyte esterase), patients
who were foreigners, patients who had unstable medical
conditions or indwelling urethral catheter, were excluded.
We reviewed the hospital records relating to collected
data about age, gender, body mass index (BMI), underlying
diseases, symptoms and complications of the COVID-19
infection. Patients were informed and consented to this
study by telephone. Patients who met with the eligible
criteria and were willing to participate in the study
answered the online survey questions by themselves
and undertook urinalysis by urine dipstick test at wards.
e online survey questions consisted of symptoms
of COVID-19 infection, number of daytime voiding,
number of nocturia, whether they voided more frequently
during COVID-19 infection, whether they had urgency
symptom during COVID-19 infection, whether they
had increased number of nocturia during COVID-19
infection, or whether they had urgency incontinence
during COVID-19 infection. OABSS (Overactive Bladder
Symptoms Scores) questionnaire (total score 15) and
ICIQ-LUTS (International Consultation on Incontinence
Modular Questionnaires - Lower Urinary Tract Symptoms)
in the part of storage symptoms subscale (total score 16).
Patients who had any one of the following, which were
cough, runny nose, sore throat and nasal congestion were
dened as having upper respiratory tract infection symptoms
(URI). Patients who had any one of the following, which
were URI symptoms, fever, anosmia, chest discomfort,
rash, diarrhea, pneumonia were dened as being in the
symptomatic COVID-19 infection group. Patients who
did not develop any symptoms were dened as being in
the asymptomatic COVID-19 infection group. Pneumonia
was diagnosed by chest x-ray that was reported by a
radiologist.
e OABSS is the questionnaire that contains questions
including all the important content of storage symptoms,
which are frequency >7 times, urgency, nocturia and urge
incontinence. erefore, storage symptoms group was
dened by using the criteria that patients had to answer
that they developed one or more symptoms of frequency,
urgency, nocturia, urge incontinence concomitant with
having OABSS equal to or greater than 1 score during
infection. Patients who did not develop any storage
symptoms during infection or had OABSS score 0 were
dened as no storage symptoms group.
Patients who had BMI equal to or greater than 25
kg/m
2
were dened as obesity group in this study.
e urine dipstick test that showed any of the following;
those which were leukocyte positive, proteinuria or
hematuria were classied as a positive result.
e data were analyzed by using STATA statistical
soware version 15.0. We used the student T-test for
parametric data, Mann-Whitney U test for non-parametric
data and Fisher-Exact test for categorical data. e binary
regression analysis was used for analyzing factors that
were associated with storage symptoms in COVID-19
infection patients. e statistically signicant were dened
as p-value <0.05.
RESULTS
From 2,357 COVID-19 patients admitted, there
were 136 (5.77%) COVID-19 patients who met the
eligible criteria and were willing to participate in the
study; 61 (44.85%) patients had storage symptoms and
75 (55.15%) patients did not have storage symptoms.
For the demographic data as shown in Table 1,
patients were divided into two groups by answering
the question as to whether they had storage symptoms
concomitant with OABSS score ≥1 during the COVID-19
infection, which was dened as having storage symptoms
and patients who not develop any storage symptoms or
had OABSS score 0 were dened as no storage symptoms.
e mean age of COVID-19 patients who had storage
symptoms was 36 years old and 33 years old for patients
who did not have storage symptoms, which were not
statistically dierence between the groups. ere were
37 (60.66%) patients in the storage symptoms group who
had one or more of the underlying diseases, which was
obesity, diabetic disease, hypertension, dyslipidemia,
asthma/COPD. Meanwhile, 38 (50.67%) patients in the
no storage symptoms group had one or more underlying
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TABLE 1. Demographic data.
Storage symptoms
1
No Storage symptoms
2
p-value
(n=69) (n=67)
Age,yearmean(SD) 36(14) 33(12) 0.221
Gender
Male,n(%) 26(42.62) 28(37.33)
Female,n(%) 35(57.38) 47(62.67) 0.598
Overall underlying disease
Yes, n (%) 37 (60.66) 38 (50.67)
No,n(%) 24(39.34) 37(49.33) 0.299
Obesity
Yes,n(%) 28(45.90) 39(52.00)
No, n (%) 33 (54.10) 36 (48.00) 0.864
Diabetic disease
Yes,n(%) 5(8.20) 10(13.33)
No, n (%) 56 (91.80) 65 (86.67) 0.416
Hypertension
Yes,n(%) 5(8.20) 10(13.33)
No, n (%) 56 (91.80) 65 (86.67) 0.416
Dyslipidemia
Yes,n(%) 3(4.92) 7(9.33)
No, n (%) 58 (95.08) 68 (90.67) 0.511
Asthma/COPD
Yes, n (%) 1 (1.64) 3 (4.00)
No,n(%) 60(98.36) 72(96.00) 0.628
Admitted ward
ICU,n(%) 3(4.92) 3(4.0)
Cohort,n(%) 32(52.46) 21(28.00)
Fieldhospital,n(%) 26(42.62) 51(68.00) 0.007
Intravenousuidtherapy
Yes,n(%) 3(4.92) 3(4.00)
No,n(%) 58(95.08) 72(96.00) 1.000
Overall COVID-19 symptoms
Asymptomatic,n(%) 10(16.39) 26(34.67)
Symptomatic, n (%) 51 (83.61) 49 (65.33) 0.019
URI symptoms
2
Yes,n(%) 44(72.13) 45(60.00)
No,n(%) 17(27.87) 30(40.00) 0.151
Fever
Yes,n(%) 35(57.38) 24(32.00)
No,n(%) 26(42.62) 51(68.00) 0.003
Swatesutipun et al.
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TABLE 1. Demographic data. (Continue)
Storage symptoms
1
No Storage symptoms
2
p-value
(n=69) (n=67)
Anosmia
Yes, n (%) 11 (18.03) 10 (13.33)
No,n(%) 50(81.97) 65(86.67) 0.482
Chest discomfort
Yes, n (%) 11 (18.03) 10 (13.33)
No,n(%) 50(81.97) 65(86.67) 0.482
Rash
Yes,n(%) 2(3.28) 1(1.33)
No,n(%) 59(96.72) 74(98.67) 0.587
Diarrhea
Yes, n (%) 11 (18.03) 5 (6.67)
No, n (%) 50 (81.97) 70 (93.33) 0.060
Pneumonia
Absent,n(%) 26(42.62) 17(22.67)
Present, n (%) 35 (57.38) 58 (77.33) 0.016
Abbreviation: SD: standard deviation, URI: respiratory tract infection.
1
Storage symptom were dened as patients who had one or more symptoms of frequency voiding, urgency, urge incontinence, nocturia
concomitant with OABSS score ≥ 1 during COVID-19 infection.
2
Patients who did not develop any storage symptom during infection or had OABSS score 0 during COVID-19 infection.
3
URI symptoms were dened as having one or more symptoms of cough, runny nose, sore throat, nasal congestion.
diseases, which was not statistically dierent between two
groups. Most of the patients in the storage symptoms
group (52.46%) were admitted to the cohort ward, in
contrast to no storage symptoms group that most of
the patients (68%) were admitted to the eld hospital.
Patients in the storage symptoms group were admitted
to the cohort ward greater than the no storage symptoms
group (52.46% VS 28.00%, p-value 0.007). ere were
only six patients who received intravenous uid during
admission, 3 patients in the storage symptoms group and
3 patients in the no storage symptoms group, which was
not statistically dierent between the two groups.
Patients who had storage symptoms had statistically
signicantly COVID-19 symptoms greater than the no
storage symptoms group (p-value 0.019). Moreover,
fever and pneumonia were signicantly related to storage
symptoms (p-value <0.05). Although diarrhea was not
statistically signicant but it had the tendency to be
related to storage symptoms (p-value 0.06)
From Table 2, Patients who had storage symptoms
had an average daytime frequency higher than that of
the no storage symptoms group, at 5.9 and 3.8 (p-value
<0.001), respectively. Meanwhile, the number of nocturia
were higher in who had storage symptoms, which were
2.0 and 1.0 (p-value <0.001). Patients who had storage
symptoms had urgency signicantly higher than no storage
symptoms group (67.21% VS 6.67%, p-value <0.001).
ere were only 4 patients who had urge incontinence
higher than in storage symptoms group but not statistically
signicant. Moreover, the OABSS and ICIQ storage
subscale in the storage symptoms group were higher
than no storage symptoms group, 3.2 VS 0.9 and 4.5
VS 1.7 (p-value < 0.001), respectively.
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TABLE 2. Data of storage symptoms between two groups.
Storage symptoms
1
No Storage symptoms
2
p-value
(n=61) (n=75)
Daytimefrequency,mean(SD) 5.9(2.9) 3.8(2.1) <0.001
Nocturnalfrequency,mean(SD) 2.0(1.2) 1.0(1.2) <0.001
Urgency
Present,n(%) 41(67.21) 5(6.67)
Absent,n(%) 20(32.79) 70(93.33) <0.001
Urgency urinary incontinence during admission
Present,n(%) 3(4.92) 1(1.33)
Absent,n(%) 58(95.08) 74(98.67) 0.325
OABSS,mean(SD) 3.2(2.2) 0.9(1.0) <0.001
ICIQ(storage),mean(SD) 4.5(2.7) 1.7(2.3) <0.001
Abbreviation: SD: standard deviation, URI: respiratory tract infection, OABSS: overactive bladder symptom scores, ICIQ: International
Consultation on Incontinence Modular Questionnaires.
1
Storage symptoms were dened as patients who had one or more symptoms of frequency voiding, urgency, urge incontinence, nocturia
concomitant with OABSS score ≥ 1 during COVID-19 infection.
2
Patients who did not develop any storage symptom during infection or had OABSS score 0 during COVID-19 infection.
e factors associated with storage symptoms
From univariable analysis, the underlying diseases
which were obesity, diabetes, hypertension, dyslipidemia,
asthma and COPD were not associated with storage
symptoms during COVID-19 infection. However, the
symptoms and complication of the COVID-19 infection
related to storage symptoms, particularly fever and
pneumonia are signicant related to storage symptoms but
the URI symptoms, rash, anosmia and chest discomfort
were not related to storage symptoms. Aer using the
multivariable analysis factor associated with storage
symptoms in COVID-19 patients by using the factors
that would relate to storage symptoms, pneumonia is
the only factor that was signicantly related to storage
symptoms in this study (OR 2.92 (1.04-8.21), p-value
0.042). Fever had a tendency to be related to storage
symptoms but was not statistically signicant (OR 2.12
(0.93-4.85), p-value 0.072) (Table 3).
TABLE 3. e Multivariable analysis factors associate with storage symptoms in COVID-19 patients.
Factor Oddratio(95%CI)
1
p-value
Age in year 1.01 (0.98 - 1.04) 0.346
Malegender 1.24(0.57-2.71) 0.584
Diabetic mellitus 0.34 (0.09 - 1.31) 0.119
Obesity 0.46 (0.19 - 1.13) 0.091
Fever 2.12(0.93-4.85) 0.072
Pneumonia 2.92(1.04-8.21) 0.042
Diarrhea 2.84(0.79-10.15) 0.108
1
e binary regression analysis was used for analyzing factors that associated with storage symptoms in COVID-19 infection patients.
Swatesutipun et al.
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e presence of leukocyte, hematuria or proteinuria
related to the severity of COVID-19 infection and
storage symptoms
From 136 COVID-19 patients, there were 34 patients
who undertook the urine dipstick test. Even though they
were not statistically signicant, the patients who had
abnormal urine dipstick tests were more likely to have
more storage symptoms, fever, URI and pneumonia
(Table 4).
DISCUSSION
e prevalence of the urinary storage symptoms
in COVID-19 patients from our study population was
44.85%. Patients in the storage symptoms group had
frequent voiding, urgency, nocturia, OABSS and ICIQ
storage subscale signicantly higher than the no storage
symptoms group (p-value <0.001). e prevalence of these
symptoms was quite high but there was no information
about the abnormal storage symptoms to warn people that
this might be a sign of COVID-19 infection. Similar to
the previous studies
4,5
, our study demonstrated that most
COVID-19 patients could have more frequent voiding,
nocturia and urgency during the infection. Patients in
our study who had COVID-19 pneumonia were more
likely to have abnormal storage symptoms than patients
who had not. All patients were treated by conservative
treatment which were prompt voiding, avoiding caeine
and adjusting uid intake. None of these patients took
medication or underwent any intervention to relieve
symptoms.
e SAR-CoV-2 virus could be isolated from the
urine sample. Hence, this virus would be contagious
by urine.
3
e study by Kashi AH et al and Roshandel
et al. demonstrated that the rate of SAR-CoV-2 viral
shedding in urine was 1.18% and the detection rate
of virus in urine was 4.5-8%. Even though the rate of
shedding was lower than in nasopharyngeal and rectum,
the viral shedding in urine was higher in patients who had
greater severity of the disease and also related to higher
mortality.
7,8
From our study, patients who had fever,
diarrhea and pneumonia had a higher number of storage
symptoms than the asymptomatic or mild symptoms
group. erefore, as well as showing storage symptoms
of COVID-19 patients, the SAR-CoV-2 virus might also
be transmitted to other people by urine contamination.
Currently, the pathophysiology of storage symptoms
is still unclear. ere are several mechanisms that could
explain the storage symptoms. Firstly, the SAR-CoV-2
can transmit and replicate in the urothelial cells of the
bladder via angiotensin converting enzyme 2 (ACE2)
receptors in the viremia stage and result in viral cystitis.
9,10
Secondly, the SAR-CoV-2 virus can cause endothelitis
which could irritate bladder and result in storage symptoms.
Lastly, the SAR-CoV-2 virus can cause inammation
from immunologic response as a previous study found
inammatory cytokine IL-6, IL-8, IP-10 increase in urine
TABLE 4. e presence of leukocyte, hematuria or proteinuria related to the severity of COVID-19 infection and
storage symptoms.
Symptoms Abnormal urine dipstick
1
(25) Normalurinedipstick(9) p-value
Storage symptoms
2
, n (%) 14 (56.00) 3 (33.33) 0.438
Frequency,n(%) 11(44) 2(22.22) 0.427
Urgency,n(%) 7(28) 3(33.33) 1.000
Daytimefrequency,mean(SD) 4.7(3.1) 4.4(3.3) 0.823
Nocturia,mean(SD) 1.8(1.4) 1.2(0.6) 0.241
Fever,n(%) 7(28) 2(22.22) 1.000
URI
3
, n (%) 11 (44) 6 (66.67) 0.438
Pneumonia,n(%) 2(8) 1(11.11) 1.000
Abbreviation: SD: Standard deviation, URI: upper respiratory tract infection.
1
abnormal urine dipstick was dened by positive for any of the following, leukocyte, hematuria, or proteinuria.
2
Storage symptom was dened as patients who voided more frequently or had urgency symptom during COVID-19 infection.
3
URI symptoms were dened as having one or more symptoms of cough, runny nose, sore throat, nasal congestion
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of COVID-19 patients and these patients had urgency,
frequency and nocturia.
11
e limitation of our study was that this study was
carried out as a cross-sectional study because it was
dicult to communicate with patients and collect the
data during this severe pandemic situation. erefore,
we cannot identify the true causal relation of the risk
factors associated to abnormal storage symptoms. We
could simply imply the probability of the factors that
might be related to storage symptoms from the high rate
of concomitance with the storage symptoms during the
illness as the prediction model of the study. To identify
the true eect of the factors, a cohort study could be
undertaken in the future. Moreover, we did not collected
the data about the frequency of voiding and nocturia before
infection because from our pilot study, most of the patients
were not willing to answer too many questions and most
of them could not remember. In order to avoid recall
bias and disturb patients during their illness, therefore,
we did not collect the data before the illness. Another
limitation of our study was we could not follow up the
symptoms of patients aer recovery from the illness
because of limited access to the contact information of
the patients aer they went home. However, the study
by Welk et al. reported that COVID-19 patients who had
storage symptoms during illness did not have increased
risk of long term bladder dysfunction.
12
From our study, underlying disease, which were
obesity, diabetes, hypertension, dyslipidemia, and asthma/
COPD were not signicantly related to storage symptoms.
Most of the patients who had storage symptoms were
admitted to the cohort ward (52.46% VS 28%, p-value
0.007). is data was coherent with the data regarding
COVID-19 symptoms in patients who had fever and
pneumonia were statistically signicantly related to
storage symptoms. ese might occur because most
of the patients who had pneumonia and more severe
disease were admitted to the cohort ward. However, apart
from the viral cystitis from the COVID-19 infection that
resulted in storage symptoms, there were many factors
that might also be related to storage symptoms, for
example, resulting from increasing uid intake during
illness, anxiety or cold temperature of the air conditioning
room, glucosuria in diabetic patients.
5
Generally, patients
who were admitted to ICU might be aected from the
intravenous uid, colder temperature than cohort ward
and eld hospital that could cause storage symptoms
such as frequency urination. Even though our study
demonstrated that intravenous uid was not associated
with storage symptoms, there were only 6 patients who
were admitted to ICU, therefore the sample size of this
group was too small to conclude the association between
ICU patients and storage symptoms in this study. None
of the patients in this study received a bronchodilator.
From multivariable analysis, only pneumonia was
signicantly associated with storage symptoms (p-value
0.042). Fever had a tendency to be related to storage
symptoms but was not statistically signicant. ese
might be because patients who had fever not only had
involvement from viral cystitis but also aected from
increased uid intake and cold temperature of the air
conditioning room.
Rui Liu et al. found red blood cell and proteinuria
are signicantly higher in COVID-19 patients. Patients
who had glucosuria or proteinuria were more likely to
have more severe COVID-19 disease.
13
From our study,
even though there they were not statistically signicantly
dierent, the patients who had leukocyte, erythrocyte
or proteinuria positive from the dipstick test tended to
have more storage symptoms and more fever, URI, and
pneumonia.
Regarding the information from our study and
previous studies, medical personnel, especially urologists
and general physicians, should be aware that the patients
who were infected by SARS-CoV-2 virus might present
at the hospital with abnormal storage symptoms and
abnormal urinalysis that mimic the urinary tract infection.
Moreover, in order to increase the awareness of carrying
the disease and risk of transmitting the virus to others,
people should know that storage symptoms could also
be the symptoms of the COVID-19 virus.
CONCLUSION
Our study demonstrated that SARS-CoV-2 virus
infection in patients who had pneumonia and fever was
associated with abnormal storage symptoms, including
frequency, urgency and nocturia. ese storage symptoms
may be related to the severity of COVID-19 disease.
Patients and medical personnel should be aware that
storage symptoms might be found together with fever and
pneumonia as well as presenting symptoms of COVID-19.
ACKNOWLEDGEMENT
We would like to express our special thanks of
gratitude to Dr. Chatchai Mingmalairak, Miss Natnaree
Sangjan, as well as all nurses at the ICU, cohort ward
and eld hospital who helped in collecting the data and
taking care of COVID-19 patients. We would also like
to thank Ms Sam Ormond and Mr.Peter Berridge for
her/his assistance with proofreading and editing this
manuscript for clarity in English.
Conict of interest
We have no conict of interest.
Swatesutipun et al.
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