Paramedic laryngoscopy in the simulated difficult airway: comparison of the Venner A.P. Advance and GlideScope Ranger video laryngoscopes.

OBJECTIVES: This study assesses intubation times and potential trauma with two new portable video laryngoscopes, the GlideScope Ranger (GSR) and the Venner A.P. Advance (APA), in a simulated difficult prehospital airway. The GSR has a hockey stick shape and is inserted by a different (midline) technique compared with direct laryngoscopy and requires the use of a stylet. The APA has a handle similar to a direct laryngoscope, but with an angulated difficult airway blade. The APA is designed to have an intuitive insertion technique somewhat similar to that of direct laryngoscopy (lateral tongue displacement) and has a guiding mechanism that foregoes the need for a stylet.

METHODS: Thirty qualified paramedics received a short demonstration of each device and were asked to intubate a modified Grade III difficult laryngoscopy mannequin in a random order (closed envelope technique). Optimal view and tracheal intubation times were recorded, and potential trauma assessed by the number of additional discrete forward advances and by visual analog scale (VAS). Direct laryngoscopy was used as a comparator. The Wilcoxon rank sum test was used for intubation times, optimal view times, percentage of glottis opening (POGO) seen, and objective trauma assessment. Student's paired t-test was used for subjective trauma assessment and a Bonferroni correction was used for the primary outcome measures.

RESULTS: Participants declared a median of 60 (range 20 to 300) previous intubations. Time to achieve optimal view between APA and GSR was not different (20 seconds vs. 19 seconds; p = 0.19), but tracheal intubation was significantly faster with the APA (25 seconds vs. 46 seconds; p < 0.0001). Intubation success was ultimately 97% in both groups. Participants judged subjective trauma to be less for the APA than GSR on a VAS (1.6 cm vs. 3.3 cm; p < 0.001). More than three additional forward advances were required in 43% of GSR and 0% of APA intubations.

CONCLUSIONS: Following a brief demonstration to paramedics naïve to video laryngoscopy, the APA demonstrated earlier intubation, fewer additional discrete forward advances of the tube, and less participant-judged subjective trauma when compared to the GSR in this simulation model.