Effect of paratracheal pressure on the glottic view during direct laryngoscopy: a randomized, double blind,...

Cricoid pressure (CP) is commonly used during rapid sequence induction and intubation to prevent regurgitation and aspiration of gastric contents. However, its effectiveness and safety have been questioned. Paratracheal pressure (PP) has emerged as a potential alternative. This study aimed to compare the adverse effects of PP versus CP on the glottic view during direct laryngoscopy.

This randomized, double-blind, non-inferiority trial included 200 adult patients undergoing general anaesthesia. Participants were randomly assigned to receive either PP or CP during anaesthesia induction. The primary endpoint was the incidence of deteriorated laryngoscopic view, assessed by a blinded observer using the modified Cormack-Lehane grade with a non-inferiority margin of -10%. Secondary endpoints included the percentage of the glottic opening score, ease of mask ventilation, changes in ventilation volume and peak inspiratory pressure (PIP) during mechanical mask ventilation, ease of tracheal intubation, and resistance during tube advancement.

PP was found to be non-inferior to CP regarding the incidence of deteriorated laryngoscopic view (0% vs. 20%; absolute risk difference, -20%; 2-sided 95% CI, -26.68 to -13.32; P < 0.001). Mask ventilation was easier with PP (OR, 0.60; 95% CI, 0.15-2.17; P = 0.284). The increase in PIP was significantly smaller in the paratracheal group (0.47 (0.31-0.63) vs. 1.46 (1.22-1.69); P = 0.002).

PP is non-inferior to CP concerning its effect on the glottic view during direct laryngoscopy. Additionally, PP may facilitate easier mask ventilation and reduce PIP during mechanical ventilation, making it a viable alternative to cricoid pressure.