The predictive Value of Four Predictive Tests for Difficult Laryngoscopy in Chiang Rai Hospital
Keywords:
ความยากของการเห็นเส้นเสียงขณะใส่ท่อช่วยหายใจ, การประเมินทางเดินหายใจAbstract
Preoperative evaluation is important in the detection of high risk patient for difficult tracheal intubation. Several predictive test for assessing a patient’s airway for difficult laryngoscopy, hower, predictive reliability’s unclear. Intercessor gap, Thiopental distance, Mallmpati classification, ratio of patient’s height ot TMD (ratio of height to TMD=RHTMD) are simple bed-side tests for assessing airway of patients. This study aims to evaluate and compare the accuracies of interincisor gap, Thiopental distance, Mallmpati classification and ration of height to TMD for prediction the Difficult tracheal intubation.
This retrospective study in the anesthetized patients n 2007. The authors collected data on 340 patients: inclusion criteria is age> 18 yrs. Elective case, generalize acsthesia. ASA class 1, 2 and exclusion criteria is emergency case., rapid sequence induction, C-spine, BMI> 35kg/m2, pregnancy GA>20wks, no teeth by using computer analyzided and medical records.Age, sex, height, weight, ASA, interincisor gap, TMD, Mallampati classification, RHTMD were collected. Difficult intubation was defined in the present study by Cormack and Lehane grade 3 or 4. The sensitivity, specificity, and positive and negative predictive values of each of the predictive tests were calculated according to standard formulae. The odd ratio (95% confidence interval), Chisquare test and <0.05 is the significant analysis statistics.
The result of the study were as follows: Interincisor gap<3.5cm (sensitivity 70%. Specificity 81%), TMD<6.5cm(sentsitivity 48%, specificity 91%), Mallampati class3or4(sensitivity 52% specificity 97%), RHTMD>23.5 (sensitivity 52%, specificity 89%), odds ratio (95% confidence interval) of the interincisor gap<3.5cm, TMD<6.5cm. Mallampati class 30r4, RHTMD >23.5 were 0.096(040-0.229), 0.110(0.047-0.256),0.031(0.011-0.082), and 0.117(0.047-0.256) respectively. Mallampati class 3or4 is hgh sensitivity, high NPV andhighest of specificity and PPV may the best useful screening test for defficult laryngoscopy.
References
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