Non-inferiority randomized controlled trial comparing CricOid pressure and para-laryngeal pressure in parturients undergoing cesarean delivery: NiCOP trial.

BACKGROUND

Cricoid pressure has been surrounded with controversies regarding its effectiveness. Application of ultrasound-guided para-laryngeal (PL) force has been shown to occlude the esophagus effectively compared with cricoid pressure (CP) in awake patients. We hypothesized that there would be no meaningful difference in the change in antero-posterior esophageal diameter from with application of cricoid or para-laryngeal pressure in parturients undergoing cesarean delivery under general anesthesia.

METHODS

In this prospective, randomized, non-inferiority trial, 40 parturients scheduled for elective cesarean delivery under general anesthesia were randomized to receive rapid sequence induction with either cricoid pressure (n = 20) or para-laryngeal pressure (n = 20). The antero-posterior diameter of the esophagus, measured by sonography, was the primary outcome. Visualization of the esophagus, its position in relation to the glottic aperture, esophageal occlusion, percentage of glottic opening (POGO), time to intubation, first pass success rate, overall success rate and adverse events like desaturation or bronchospasm were secondary outcomes.

RESULTS

The mean change in anterior-posterior diameter in the CP group was 0.17 ±0.1 cm vs. 0.28 ±0.1 cm in the PL group. The mean difference (CP-para-laryngeal pressure) between the groups was -0.11 (95% CI -0.17 to -0.1) cm. As the upper limit of the 95% CI was lower than the prespecified non-inferiority margin (δ = -0.2), non-inferiority was established (P <0.001]. There was no significant difference in the POGO score (P = 0.818), time to intubation (P =0.55), or intubation attempts (P = 0.99).

CONCLUSIONS

Para-laryngeal pressure was non-inferior to CP in occluding the esophagus in parturients undergoing cesarean delivery under general anesthesia and furthermore, no significant deterioration in intubation parameters was seen.