To Örebro University

Background: The use of cricoid pressure is controversial, and its ability to occlude the esophagus has been questioned. In this study, high-resolution solid-state manometry was used to analyze pressure changes in the upper esophagus from cricoid pressure during modified rapid sequence induction. This is a secondary analysis of data from a previous study.

Methods: Seventeen healthy volunteers participated in a double-blind, randomized, placebo-controlled, cross-over study with primary aim to compare differences in the barrier pressure on the lower esophageal sphincter during rapid sequence induction with or without alfentanil. Standardized cricoid pressure of 30 N was applied 2 minutes after propolipid injection and held for 15 seconds and pressures in the esophagus were measured.

Results: Cricoid pressure resulted in a pressure increase of 127 +/- 98 mmHg (95% CI: 73-182) (placebo) and 123 +/- 74 mmHg (95% CI: 84-162) (alfentanil) at the level of the upper esophageal sphincter (UES), compared to baseline.

The pressure difference around the UES compared to the proximal esophagus during cricoid pressure application was 165 +/- 100 mmHg (placebo) and 159 +/- 87 mmHg (alfentanil) (mean +/- 1 SD).

Conclusion: This study using high-resolution solid-state manometry under clinically relevant conditions shows that 30 N cricoid pressure generates high pressure in the area of the UES, far exceeding the levels previously considered necessary to prevent regurgitation. Additional studies are needed to clarify the effectiveness of cricoid pressure in preventing passive regurgitation before it is rejected as a part of rapid sequence induction.