A noninferiority trial comparing left paratracheal pressure versus cricoid pressure on tracheal intubation conditions using the Pentax Airway Scope

There are no studies evaluating the effect of left paratracheal pressure (PP) on difficulty of intubation using Pentax Airway Scope (Pentax), so we conducted this study to show that PP was not inferior to cricoid pressure (CP) in intubation time using the Pentax. Patients aged 19–70 years, with an American Society of Anesthesiologists physical status 1 or 2, and undergoing otorhinolaryngological, gynecological surgery, and cholecystectomy at a single university hospital were enrolled. Intubation was performed using the Pentax under PP or CP of 30 N. The primary outcome was intubation time, and the secondary outcomes were tube advancement difficulty and glottis view. The mean difference in intubation time (PP group − CP group) was − 4.19 s (95% CI − 8.24 to − 0.15), which was within the non-inferiority margin of 6.5 s, thus proving non-inferiority of the PP compared with the CP group. However, the score for tube advancement difficulty was significantly lower in the PP group than in the CP group (p = 0.02). PP did not prolong the intubation time and showed comparable intubation conditions to CP in intubation using the Pentax. Therefore, PP may be a good alternative maneuver to prevent gastric regurgitation during intubation using the Pentax.