Influence of head and neck position on performance of the Ambu® AuraGain™ laryngeal mask: a randomized crossover study.

Abstract

The purpose of this study was to investigate the influence of different head and neck positions on the performance of the Ambu® AuraGain™, a novel laryngeal mask with anatomical curvature. Oropharyngeal leak pressure, expiratory tidal volume, peak inspiratory pressure, ventilation score, and fiberoptic view score through the AuraGain™ were measured in the neutral, flexed, and extended neck positions as well as the right rotated head and neck position in each patient in a random order. A total of 40 patients were enrolled, and data from 39 patients were analyzed. Oropharyngeal leak pressure was significantly higher in the flexed neck position (32.1±7.2 cmH2O, 95% CI: 3.3 to 7.8; P<0.001) and lower in the extended neck position (22.0±6.8 cmH2O, 95% CI: -7.0 to -2.0; P=0.001) compared with those in the neutral position (26.6±7.5 cmH2O). The ventilation score was comparable in all positions. The fiberoptic view score was higher in the extended neck position (P<0.001) and right rotated head and neck position (P<0.001) compared with that in the neutral position; the vocal cords were most easily visualized in the extended neck position. Head and neck position affects the oropharyngeal seal of the AuraGain™, as evidenced by the oropharyngeal leak pressure, but not enough to impede positive-pressure ventilation. Neck flexion can be used when a better oropharyngeal seal is needed, and neck extension and right rotation of the head and neck may facilitate endotracheal intubation using the AuraGain™ as a conduit.