Inhalational Agent: An Alternative Pain Relief

Papiroon  Noitasaeng

Authors

Papiroon Noitasaeng Siriraj Hospital

Keywords:

pain relief, spinal/epidural route, intramuscular/ intravenous route, inhalational route, oxygen-nitrous oxide gas mixture

Abstract

ain killers can be performed via spinal/epidural route under the supervision of anesthesia personnel with clinically standard monitoring; intramuscular/intravenous route by using morphine, a well-known narcotic and pain relief, extracted from natural opium; and inhalational route by agents relating to the alveolar concentration and affecting on the central nervous system such as Methoxyflurane or Entonox that have been applied in medicine for more than 40 years. Entonox is an equal mixture of nitrous oxide and oxygen. Notably, nitrous oxide, a well-diffusion with second gas effect, produces a rapid increase in alveolar concentration of oxygen. Drug has effect on brain and spinal cord resulting in patient’s pain relief and comfort. Interestingly, patients themselves are able to administer drug following the physicians’ advice by deeply and slowly breathe in 8-10 times. Entonox has peak onset of 3-5 minutes and wean off of 5-8 minutes after discontinuing inhalation. As a result, it is commonly administered in painless labor, intravenous cannulation, dental works or gastrointestinal duodenoscopy. Adverse effects are diffusion hypoxia, numbness and muscle cramp in hands and feet, dizziness, drowsiness, nausea, vomiting, and dryness of mouth. Additionally, since nitrous oxide can diffuse thoroughly into body space and cavity, Entonox should be cautiously managed in some procedure such as bowel obstruction.

References

1. Fillingim RB. Individual differences in pain: understanding
the mosaic that makes pain personal. Pain 2017;158(Suppl 1):
S11-S18.
2. Kleisiaris CF, Sfakiankis C, Papathanasiou IV. Health care
practices in ancient Greece: The Hippocratic ideal. J Med
Ethics Hist Med 2014;7:1-5.
3. Treede RD. The International Association for the Study of
Pain definition of pain: as valid in 2018 as in 1979, but in
need of regularly updated footnotes. Pain Rep 2018; 3: e643.
4. Campbell CM, Edwards RR. Ethnic differences in pain and
pain management. Pain Manag 2012;2:219-30.
5. Wijayanti E. Teaching pain management to student nurses:
a literature review. Nurse Media J Nurs 2014;4:715-32.
6. Peláez FJR, Taniguchi S. The Gate theory of pain revisited:
modeling different pain conditions with a parsimonious
neurocomputational model. Neural Plasticity 2016. doi.
org/10.1155/2016/4131395
7. Brant JM. Assessment and management of cancer pain in
older adults: strategies for success. Asia Pac J Oncol Nurs
2018;5:248-53.
8. Mendel LM. Constructing and deconstructing the Gate
Theory of pain. Pain 2014 doi:10.1016/j.pain.2013.12.010.
9. Khan KS, Hayes I, Buggy DJ. Pharmacology of anaesthetic
agent II: inhalation anaesthetic agents. Continuing Education
in Anaesthesia, Critical Care & Pain 2014;14:106-11.
10. Lim G, Facco FL, Nathan N, et al. A review of the impact of
obstetric anesthesia on maternal and neonatal outcomes.
Anesthesiology 2018;129:192-215.
11. Techamuanwaiwit S. Pain and pain management of mothers
during the first stage of labor.
12. Journal of Health and Nursing Research 2015;31:114-5.
13. Royal College of Anaesthetists. Guidelines for the provision
of anaesthesia services; chapter 2, 3, 4. 2019 [Internet].
Cited 2020 April 12. Available from: https://www.rcoa.ac.uk/
gpas/chapter-2.
14. Schmitz R. Friedrich Wilhelm Sertürner and the discovery of
morphine. Pharmacy in history 1985;27:61-74.
15. Barnes J. Pethidine in labour: result in 500 cases. Br Med J
1947;5:437-42.
16. Al-Hasani R, Bruchas MR. Molecular mechanisms of opioid
receptor-dependent signaling and behavior. Anesthesiology
2011;115:1363-81.
17. Butterworth JF, Mackey DC, Wasnick JD, editors. Analgesic
agent. In: Morgan & Mikhail’s. Clinical Anesthesiology. 5th
edition. New York: McGraw-Hill; 2013. p. 189-98.
18. Mobaraki N, Yousefian M, Sakaki M. A randomized controlled
trial comparing use of enthonox with pethidine for pain relief
in primigravid women during the active phase of labor.
Anesth Pain Med 2016;6:e37420.
19. Vasconcellos KD, Sneyd JR. Nitrous oxide: are we still in
equipoise? A qualitative review of current controversies. Br J
Anaesth 2013;111:877-85.
20. Buhre W, Disma N, Hendrickx J, et al. European Society of
Anaesthesiology Task Force on nitrous oxide: a narrative
review of its role in clinical practice. Br J Anaesth 2019;122:
587-604.
21. Porter KM, Dayan AD, Dickerson S, Middletun PM. The role
of inhaled methoxyflurane in acute pain management. Emerg
Med 2018;10:149-164.
22. ENTONOX® The essential guide. [Internet]. Cited 2020 April
12. Available from: https://www.bochealthcare.co.uk/en/
images/entonox_essential_guide_hlc401955_Sep10_
tcm409-64836.pdf.
23. Young A, Ismail M, Papatsoris AG, et al. Entonox® inhalation
to reduce pain in common diagnostic and therapeutic
outpatient urological procedures: a review of the evidence.
Ann R Coll Surg Engl 2012;94:8-11.
24. Likis FE, Andrews JC, Collins MR, et al. Nitrous oxide for the
management of labor pain: a systematic review. Anesth
Analg 2014;118:153-67.
25. Richardson MG, Lopez BM, baysinger CL, Shotwell MS,
Chestnut DH. Nitrous oxide during labor: maternal satisfaction
does not depend exclusively on analgesic effectiveness.
Anesth Analg 2017;124:548-53.
26. Welchman S, Cochrane S, Minto G, Lewis S. Systematic
review: the use of nitrous oxide gas for lower gastrointestinal
endoscopy. Aliment Pharmacol Ther 2010;32:324-33.
27. Hsu CW, Sun SF. Iatrogenic pneumothorax related to
mechanical ventilation. World J Crit Care Med 2014;3:8-14.
28. Celine C, Gunter H, Kurt A. Laughing gas abuse is no joke.
An overview of the implications for psychiatric practice. Clin
Neurol Neurosurg 2013;115:859-62.
29. Edigin E, Ajiboye O, Nathani A. Nitrous oxide-induced B12
deficiency presenting with myeloneuropathy. Cureus 2019;
11: e5331. DOI: 10.7759/cureus.5331.
30. BOC Healthcare Customer Service Centre. ENTONOX®
(medical nitrous oxide and oxygen mixture). [Internet]. Cited
2020 April 12. Available from: https://www.bochealthcare.
co.uk/en/products-and-services/products-and-services-bycategory/medical-gases/entonox/entonox.html
31. BOC Healthcare Customer Service Centre. Entonox The
essential guide. [Internet]. Cited 2020 April 12. Available
from: https://www.bochealthcare.co.uk/en/images/entonox_
essential_guide_hlc401955_Sep10_tcm409-64836.pdf
32. The Pennine Acute Hospitals NHS Trust. Entonox use in
endoscopic procedures. [Internet]. Cited 2020 April 12.
Available from: https://www.pat.nhs.uk/downloads/patientinformation-leaflets/gastroenterology/828%20Entonox%20
use%20in%20endoscopic%20procedures.pdf
33. Entonox during hospital procedures-information for patients.
[Internet]. Cited 2020 April 12. Available from: https://www.
hey.nhs.uk/patient-leaflet/entonox-hospital-procedures-information-patients.