Comparing leak pressure of LMA^® ProSeal™ versus i-gel^® at head rotation: a randomized controlled trial

The effect of head rotation on supraglottic airway (SGA) oropharyngeal leak pressure (OPLP) has not been well elucidated. The aim of this study was to help clarify which SGA device provides higher OPLP at head-rotated position.

Patients who underwent elective surgery under general anesthesia were enrolled and randomly divided into laryngeal mask airway (LMA^®) ProSeal™ and i-gel^® groups. The allocated SGA device was inserted under anesthesia. The primary outcome was OPLP, and secondary outcomes were ventilation score, expiratory tidal volume, and maximum pressure under volume-controlled ventilation (VCV) with an inspiratory tidal volume of 10 mL·kg^-1 ideal body weight and fibreoptic view of the vocal cords at 0°, 30°, and 60° head rotation.

Data from 78 and 76 patients were analyzed in the LMA ProSeal and i-gel groups, respectively. The mean (standard deviation) OPLP of the LMA ProSeal was significantly higher than that of the i-gel at the 60° head-rotated position (LMA ProSeal, 20.4 [6.5] vs i-gel, 16.9 [7.8] cm H₂O; difference in means, 3.6; adjusted 95% confidence interval, 0.5 to 6.6; adjusted P = 0.02, adjusted for six comparisons). The maximum pressure under VCV at 60° head rotation was significantly higher in the LMA ProSeal group than in the i-gel group. The expiratory tidal volume of the LMA ProSeal did not significantly change with head rotation and was significantly higher than that of the i-gel at 60° head rotation. Ventilation score, fibreoptic view of the vocal cords, and complications were not significantly different between the ProSeal and i-gel groups.

The LMA ProSeal provides higher OPLP than the i-gel at a 60° head-rotated position under general anesthesia.

Japan Registry of Clinical Trials (https://jrct.niph.go.jp) (JRCT1012210043); registered 18 October 2021.