ABSTRACT

In obese prtegnants it is very difficult to achieve, and maintain patency of airway during general anesthesia, and failed intubation constitutes the most important reason for maternal morbidity, and mortality. Many predictive tests are used in the determination of diffucult intubation In this study our aim is to evaluate the importance of these tests for determining the difficult intubation.

In our study, the files and the anaesthesic records of 252 pregnant women who had caesarean section under general anaesthesia were retrospectively screened. The body mass index (BMI), thyromental distance (TMD), sternomental distance (SMD), Wilson total risk score, Modified Mallampaty clasification, head and neck movement, retrognathia, upper lip bite test (ULBT), neck circumfarence, intubation difficulty scale (IDS) of the patients were evaluated. The sensitivity, specificity and positive predictive values of these test were calculated.

Of these 252 patients, BMIs were >30 kg/m2 for 103 patients and <30 kg/m2 for 149 patients. The incidence of difficult intubation and difficult laryngoscopy was 4 % and 7 %. A significantcorrelation was found between difficult intubation and high Mallampati scores, Cormac-Lehane grade 3 and 4, ULBT grade 3, Wilson total risk scores of ≥2, neck circumfarences >40 cm, IDS >5, and BMIs >30 kg/m2 (p<0.05). The sensitivity, specificity and positive predictive values of the tests were, 100 %, 61 %, 10 % for BMI, 90 %, 93 %, 38 % for neck circumference, 54 %, 7 %, 2 % for TMD, 76 %, 96 %, 55 % for Cormac-Lehane grade 3-4 and 63 %, 99 %, 77 % for ULBT grade 3.

The prevalence of difficult intubation in obese pregnants are higher than the population and ULBT and neck circumference are the most valuable predictive tests for the determination of this difficulty.

Keywords: Pregnancy, airway determination tests, difficult airway, intubation, obesity