Head and neck elevation beyond the sniffing position improves laryngeal view in cases of difficult direct laryngoscopy

Abstract

Study Objective: To determine the influence of head and neck elevation beyond the “sniffing position” during difficult direct laryngoscopy. Design: Prospective case series, with each patient serving as her or his control. Setting: University hospital. Patients: 21 patients scheduled for general anesthesia and endotracheal intubation, all of whom presented with a laryngoscopic grade III view (Cormack & Lehane) during direct laryngoscopy in the sniffing position. Interventions: An assistant applied external laryngeal pressure with his left hand and elevated the patient’s head and neck above the sniffing position with his right hand to improve laryngeal view. Measurements and Main Results: External laryngeal pressure and elevation of head and neck improved the laryngoscopic view in 19 of 21 patients to grade II (p = 0.001, Wilcoxon signed rank test). Beyond that, laryngoscopy with the neck maximally elevated enabled visualization of parts of the cords in six patients (30%). Conclusions: Elevation of the head and neck beyond the sniffing position may improve visualization of glottic structures in cases of difficult direct laryngoscopy, leading to better intubation performance.