Retention of laryngoscopy skills in medical students: a randomised, cross-over study of the Macintosh, A.P. Advance(™) , C-MAC(®) and Airtraq(®) laryngoscopes.

In addition to being effective and easy to learn how to use, the ideal laryngoscope should be associated with minimal reduction in skill performance during gaps in practice over time. We compared the time taken to intubate the trachea of a manikin by novice medical students immediately after training, and then after 1 month, with no intervening practice. We designed a two-period, four-group, randomised, cross-over trial to compare the Macintosh, Venner(™) A.P. Advance(™) with difficult airway blade, C-MAC(®) with D-Blade and Airtraq(®) with wireless video-viewer. A bougie was used to aid intubation with the Macintosh and the C-MAC. After training, there was no significant difference in median (IQR [range]) intubation time using the videolaryngoscopes compared with the Macintosh, which took 30 (26.5-35 [12-118])s. One month later, the intubation time was longer using the C-MAC (41 (29.5-52 [20-119])s; p = 0.002) and A.P. Advance (40 (28.5-57.5 [21-107])s; p = 0.0003)m compared with the Macintosh (27 (21-29 [16-90])s); there was no difference using the Airtraq (27 (20.5-32.5 [15-94])s; p = 0.258) compared with the Macintosh. While skill acquisition after a brief period of learning and practice was equal for each laryngoscope, performance levels differed after 1 month without practice. In particular, the consistency of performance using the C-MAC and A.P. Advance was worse compared with the Macintosh and the Airtraq. While the clinical significance of this is doubtful, we believe that reliable and consistent performance at laryngoscopy is desirable; for the devices that we tested, this requires regular practice.