The effect of verbal and video feedback on learning direct laryngoscopy among novice laryngoscopists: a randomized...

Skill acquisition in direct laryngoscopy (DL) and tracheal intubation is complex. This pilot study aims to assess feasibility and determine sample size for a subsequent trial comparing DL instruction using a Macintosh-style video laryngoscope (MacVL), with and without video recordings, with conventional DL instruction.

Medical students with no prior laryngoscopy experience were recruited during their two-week anesthesia rotation. During the first (TRAINING) week, students were randomized into three groups: Control (Macintosh direct laryngoscope), VL-1 (MacVL with real-time feedback), and VL-2 (MacVL with real-time feedback plus video recordings of laryngoscopies). During the second (TESTING) week, all students were tested using a Macintosh direct laryngoscope. Feasibility objectives were recruitment and attrition rates, ability to time and video record intubations, and the availability of a MacVL. The primary clinical outcome during the TESTING week was total time to intubate, and secondary outcomes included intubation success rate, intubating opportunities, complications, and confidence scores.

Sixty-eight of 87 (78%) consecutive medical students approached to participate in the study were recruited over 18 months. Eight (12%) students withdrew from the study, and data are available on the remaining 60 participants. The times to intubate were recorded for 92% of the TESTING intubations, but only 71% of the TRAINING intubations in the VL-2 group were video recorded. The MacVLs were available in 100% of cases. We estimate that 190 participants would be required for a study restricted to a comparison of DL vs video laryngoscopy with real-time feedback.

This pilot study establishes feasibility and provides a sample size estimate for a future RCT. Required modifications to the study protocol include wider hospital involvement and consideration regarding standardization of airway education, teaching, feedback, and patient characteristics.