Cricoid Pressure Does Not Increase the Rate of Failed Intubation by Direct Laryngoscopy in Adults
(Anesthesiology, 102:315-319, 2005)
*Department of Anesthesiology, Centre Hospitaller Affilié Universitaire de Québec, (Hôpital Enfant-Jésus), Université Laval and †Department of Social and Preventive Medicine, Laval University, Quebec City, Quebec, Canada.
Cricoid pressure (CP) is applied during induction of anesthesia to prevent regurgitation of gastric contents and pulmonary aspiration. It has been suggested, however, that CP makes tracheal intubation more challenging. This double-blind randomized study evaluated the effect of CP on orotracheal intubation by direct laryngoscopy in adults.
Seven hundred adult patients undergoing general anesthesia for elective surgery were randomly assigned to have standardized CP (n = 344) or sham CP (n = 356) during laryngoscopy and intubation. After anesthesia induction and complete muscle relaxation, a 30-second period was allowed to complete intubation with a Macintosh No. 3 laryngoscope blade. The primary end point was the rate of failed intubation at 30 seconds. The secondary end points included the intubation time, the Cormack and Lehane grade of laryngoscopic view, and the Intubation Difficulty Scale score.
Groups were similar for demographic data and risk factors for difficult intubation. The rates of failed intubation at 30 seconds were comparable for the 2 groups: 15 (4.4%) of 344 and 13 (3.7%) of 356 in the CP and sham CP groups, respectively (P = 0.70). The grades of laryngoscopic view and the Intubation Difficulty Scale score were also similar. Median intubation time was slightly longer in the CP group than in the sham CP group (11.3 and 10.4 seconds, respectively, P = 0.001).
The investigators concluded that CP applied by trained personnel does not increase the rate of failed intubation. Hence, CP should not be avoided for fear of increasing the difficulty of intubation when its use is indicated.