Risk Factors Assessment of the Difficult Airway: An Italian Survey of 1956 Patients

TLDR

In recent years, awareness and literature on recognizing and predicting difficult airways have increased, emphasizing thorough preoperative airway history, physical examination, and the use of anatomic measurements and noninvasive tests to improve assessment. The study aimed to correlate the Mallampati modified score and other indexes with laryngoscopic view to identify anatomical and clinical risk factors for difficult airway. Data were prospectively collected from 1956 consecutive elective surgery patients undergoing general anesthesia with endotracheal intubation. The Mallampati classification showed strong correlation with Cormack‑Lehane grades (overall 0.904), with Class 3 correlating with Grade 2 (0.94) and Class 4 with Grades 3 (0.85) and 4 (0.80); operator evaluation correlated 0.96 with C‑L groups, yet oropharyngeal volume correlated with difficult intubation, indicating the Mallampati score alone is insufficient for predicting difficult intubation.

Abstract

Over the last decade, there has been a heightened awareness and an increase in the amount of literature being published on recognition and prediction of the difficult airway. During the preoperative evaluation of the airway, a thorough history and physical specifically related to the airway should be performed. Various measurements of anatomic features and noninvasive clinical tests can be performed to enhance this assessment. In this study we correlated the Mallampati modified score and several other indexes with the laryngoscopic view to identify anatomical and clinical risk factors related to the difficult airway. We prospectively collected data on 1956 consecutive patients scheduled to receive general anesthesia requiring endotracheal intubation for elective surgery. The Mallampati classification versus the Cormack-Lehane (C-L) linear correlation index was 0.904. A Mallampati Class 3 correlated with a C-L Grade 2 (0.94), whereas a Mallampati Class 4 correlated with a C-L Grade 3 (0.85) and a C-L Grade 4 (0.80). Operator evaluation, performed by a simplified tracheal intubation difficulty scale, showed a linear correlation of 0.96 compared with the C-L groups. Although there is a correlation between oropharyngeal volume and difficult intubation, the Mallampati score by itself is insufficient for predicting difficult endotracheal intubation.