Comparison of the GlideScope® with the Macintosh Laryngoscope in Endotracheal Intubation during Uninterrupted Mechanical Chest Compression: A Randomised Crossover Manikin Study

Abstract

Background The GlideScope® (GS) has been shown to improve the first-attempt success rate of endotracheal intubation during continuous mechanical chest compressions compared with the conventional Macintosh laryngoscope (ML) in inexperienced hands. Yet, its value for operators with experience of emergency airway management has remained uncertain. We set out to compare their performance in the hands of experienced operators in a manikin receiving continuous mechanical chest compressions delivered by LUCAS®. Method This was a randomised crossover study. Thirty-five emergency physicians and intensivists performed intubation using GS and ML in 3 different scenarios: (1) normal airway without chest compressions; (2) normal airway with uninterrupted mechanical chest compressions; and (3) normal airway with cervical spine (C-spine) immobilisation and uninterrupted mechanical chest compressions. The sequence of scenarios and devices used were randomised. The primary outcome was the first-attempt success rate of intubation. Other data including demographics, the time required for successful intubation, complications during intubation, the visual analog scale of perceived difficulty of intubation and the preference on devices in each scenario were also collected and analyzed. Results In scenario 1, the first-attempt success rate with both laryngoscopes was 100%. In scenario 2, there was a higher first-attempt success rate with ML but it was not statistically significant (GS 97.14% vs ML 100%, p=1.00). In scenario 3, one participant failed to intubate in the first attempt with each of the laryngoscopes (GS 97.14% vs ML 97.14%, p=0.754). More dental compression was noted with GS but the difference was not statistically significant (GS 42.86% vs ML 22.86%, p=0.126). Overall, the median time for intubation with GS was significantly longer in all 3 scenarios (Scenario 1: GS 18.5s; interquartile range [IQR] 13.8 -22.2s vs ML 11.2s, IQR 9.5-14.2s, p<0.001; Scenario 2: GS 18.7s, IQR 13.1-25.2s vs ML 13.4s, 10.3-15.8s, p<0.001; Scenario 3: GS 20.8s, IQR 16.5-29.2s vs ML 14.0s, IQR 10.5-18.0s, p<0.001). More participants preferred GS in scenario 3, while ML remained the device of choice in the other two scenarios. Conclusion: GS is not superior to ML in terms of the first-attempt success rate of intubation and it takes significantly longer to intubate for experienced operator. Yet more participants prefer its use when the C-spine motion is limited. Further studies are warranted to explore its role in trauma resuscitation. (Hong Kong j.emerg.med. 2016;23:159-167)