Influence of head and neck position on ventilation using the air-Q® SP airway in anaesthetized paralysed patients: a prospective randomized crossover study.

Background: The influence of different head and neck positions on the effectiveness of ventilation with the air-Q® self-pressurizing airway remains unevaluated. This study aimed to evaluate the influence of different head and neck positions on ventilation with the air-Q® SP airway.

Methods: In this prospective, randomized crossover study, we enrolled 51 female patients who were to undergo elective gynaecological or breast surgery under general anaesthesia. An air-Q® SP airway was placed in all patients, and mechanical ventilation was performed using a volume-controlled mode with a tidal volume of 10 ml kg−1 and a respiratory rate of 12 bpm. The expiratory tidal volume, peak inspiratory pressure, oropharyngeal leak pressure, and ventilation score were assessed first for the neutral head position and then for the extended, flexed, and rotated head positions in a random order.

Results: All parameters were similar for the rotated head and neck position and the neutral position. Compared with the neutral position, the oropharyngeal leak pressure and peak inspiratory pressure decreased in the extended position but increased significantly in the flexed position (P<0.001). However, the expiratory tidal volume and ventilation score decreased significantly in only the extended position (P<0.001) but were similar in the flexed and neutral positions.

Conclusions: Ventilation was not adversely affected in the rotated or flexed head and neck positions, whereas head and neck extension negatively influenced ventilation. Clinically, it is better to avoid head and neck extension during ventilation with an air-Q® SP airway.

Clinical trial registration: NCT02402387.