Learning curves for bag-and-mask ventilation and orotracheal intubation: an application of the cumulative sum method

Abstract

Background: In this study, the authors determined the success and failure rates for interns learning bag-and-mask ventilation and orotracheal intubation. Their goal was to determine the amount of experience needed to perform these procedures correctly.

Methods: The authors recorded 695 bag-and-mask ventilations and 679 orotracheal intubations performed by 15 inexperienced interns during their 3 month-long anesthesia rotations. Learning curves for each procedure for each intern were constructed with both the standard and risk-adjusted cumulative sum methods. The average number of procedures required to attain a failure rate of 20% was estimated for each technique.

Results: Fourteen of 15 interns attained acceptable failure rates at bag-and-mask ventilation after 27 +/- 13 procedures, with a median (95% confidence interval) of 25 (15-32) procedures to cross the decision limit when considering all 15 interns. Nine of 15 interns attained acceptable failure rates at orotracheal intubation after 26 +/- 8 procedures, with a median of 29 (22-not estimable) procedures to cross the limit when considering all interns. The proportion of interns who attained acceptable failure rates for mask ventilation was greater than for tracheal intubation (93% vs. 60%, P = 0.025). Overall, our interns achieved a bag-and-mask ventilation failure rate of 20% or better after a median of 25 procedures; approximately 80% of interns achieved the goal after 35 procedures or less.

Conclusions: Participating interns developed mask ventilation skills faster than orotracheal intubation skills, and there was more variability in the rate at which intubation skills developed. A median of 29 procedures was required to achieve an 80% orotracheal intubation success rate.