Lightwand vs. Glidescope: Tracheal intubation in cadavers with a cervical spine collar

Restricted mouth opening can result in difficulty with tracheal intubation by direct laryngoscopy. The American society of anesthesiologists (ASA) practice guidelines recommend video laryngoscopes and the lightwand (LW) as alternative intubation devices1 as neither requires direct visualization of the glottis. The goal of this pilot study was to compare the performance of Glidescope® (GS) and the new prototype LW device in a simulated restricted mouth opening with cervical spine collars in cadavers. Following Research Ethics Board approval (Nova Scotia Health Authority, Halifax, Nova Scotia, Canada), four clinical grade cadavers were obtained for this study. Six staff anesthesiologists were recruited and watched an instructional video on the prototype LW device prior to being randomized to one of four cadavers with cervical spine collars in place. They were asked to perform tracheal intubation with each intubation device while being recorded on video. All videos were reviewed by an independent investigator to determine the time-to-intubation (TTI), the number of attempts, the time to airway management (TAM) or successful intubation and the success rate of tracheal intubation. 48 intubations were recorded and reviewed. After each intubation, the participant used a visual analog scale (VAS) to report the subjective degree of difficult intubation using the intubation device. Overall, there were no significant differences between the LW and the GS across all outcomes. Linear Mixed Models were used to analyze the data. There was no effect of device on TTI (95% CI [-13.4, 16.7], p=0.841) and TAM (95% CI [-13.8, 15], p=0.933). In terms of self reported VAS scores, there was no difference between devices (95% CI [-10.8, 13], p=0.859) either. The Results of our study suggest GS and LW are similarly effective in intubating cadavers with a cervical spine collar. LW relies on transillumination of the anterior neck soft tissue and is a significantly smaller device designed to be malleable, allowing for adjustments such as the degree of tip deflection. While these features might make the LW a better device to use in patients with a restricted mouth opening or a cervical spine collar, as compared to a video laryngoscope, a large clinical study is necessary to determine its utility. 30. Apfelbaum JL, Hagberg CA, Caplan RA et al. Anesthesiology. 2013; 118: 251-270.