Diagnostic Accuracy of Combined Mallampati and Wilson Score to Predict Difficult Intubation in Obese Patients: A Descriptive Cross-sectional Study

Abstract

Background: Airway protection during anesthesia is often the primary concern of anesthetists when working with obese patients and always is a difficult task due to increased exposure to harmful effects of apnea, hypoxia, and impaired respiratory mechanics. Objectives: The primary goal of this research was to determine the diagnostic accuracy of combined Mallampati and Wilson score in detecting difficult intubation in obese patients undergoing surgery by taking the Cormack-Lehane grading on direct laryngoscopy and intubation as the gold standard. Methods: This descriptive cross-sectional study was done in 300 obese patients with BMI > 29.9 kg/m2. Modified Mallampati and Wilson score was recorded preoperatively for each patient in the sitting position by the primary investigator. Endotracheal intubation grades were also recorded, and grades IIb, III, and IV were regarded as difficult intubation according to the Cormack-Lehane intubation classification. Results: The mean age was 46.76 ± 15.57 years. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the combined Mallampati and Wilson score for detecting difficult laryngoscopy and difficult intubation were 75.0, 98.8, 92.9, 95.0, and 94.6%, respectively. Conclusions: Combined Mallampatti and Wilson score is highly accurate in the initial diagnostic workup of obese patients at risk of difficult intubation. It is easy to calculate and lower the risk of intubation-related complications and failure.