A Comparison of The Mallampati Test in Both Sitting and Supine Positions to Predict Difficult Intubation in Adults Undergoing Surgery Under General Anesthesia

Abstract

Background: Difficult airway is a major concern for all anesthesiologists since failure to secure airway could lead to devastating complications and increase morbidity and mortality. Therefore airway assessment prior to induction could help us in avoidance of life-threatening complications. There are various tests to assess the airway, out of which, modified Mallampati test (MMT) is one of the common, easy and reliable methods to predict difficult airway. Usually is done with patient in sitting position. However, in certain patients in whom sitting position is not possible (suspected cervical spine injury, pelvic injury, patients in shock, etc.), the MMT can be done in supine position, therefore, we wanted to address this and to find out whether Mallampati test in supine position could offer better diagnostic accuracy or not. Objectives: to assess the Mallampati test in sitting and supine position among adult patients undergoing emergency operation to predict difficult laryngoscopy and difficult intubation. Method: This single center double blinded cross-sectional study involved 200 adult patients who underwent surgeries requiring endotracheal intubation from May 2024 to 11 2024 in the emergency operation department of Shar Teaching Hospital. The preoperative MMT was performed in both sitting and supine positions and compared with the Cormack-Lehane grading system using Chi-square test and the Statistical Package for Social Sciences (IBM SPSS Statistics 26, Chicago, IL), positive predictive value, negative predictive value, and diagnostic accuracy were calculated in the sitting and supine positions. Significance was considered when the P-value ≤ 0.05. Results: Among 200 patients, 79% had easy intubation, and 21% experienced difficult intubation based on the Cormack-Lehane grading, with both groups showing similar demographic profiles in age, gender (P>0.05). Indeed, 57.1% (n=24) of the difficult endotracheal intubation was ASA I, and only 42.8% (n=18) were ASA II, with a significant difference (P<0.001). MMT III and IV increased from 12.5% in the sitting position to 30.5% in the supine position, indicating an 18.5% rise. The sitting position was superior, with higher MMT accuracy (90.0% vs. 84.5% in supine), greater sensitivity (99.4% vs. 84.2%), and lower specificity (54.8% vs. 85.7%). Conclusion: MMT performed in the sitting position was possibly a superior predictor of difficult tracheal intubation in adult patients compared with MMT in the supine position.