2 - Comparison of hyperangulated versus standard geometry video laryngoscopy in a simulated Helicopter Emergency Medical Service setting: A randomized crossover trial

Introduction: Video laryngoscopy (VL) has become a common tool for endotracheal intubations in the prehospital setting. It has been shown useful in patients with difficult airways , showing the ability to demonstrate superior glottic views. The comparison of hyperangulated video laryngoscopy (HAVL) and standard geometry video laryngoscopy (SGVL) techniques in the prehospital setting remains minimally studied. In this study, we investigate whether there are differences between HAVL and SGVL in a Helicopter Emergency Medical Services (HEMS) setting in non-physician providers.

Methods: A three-center, randomized crossover trial was conducted with HEMS nurses and paramedics. Participants were randomized to perform 5 intubations in a grounded helicopter on an airway manikin with HAVL or SGVL first followed by 5 intubations with the subsequent technique. Outcomes included time to intubation, first-pass success rates, Cormack-Lehane scores, and subjective preferences based on survey response data.

Results: The study sample included 30 participants and showed HAVL seemed to be slightly faster than SGVL, though this failed to reach statistical significance (-1.4 seconds; 95% CI: -3.9, 1.1 seconds). HAVL and SGVL were identical in terms of first pass success and Cormack-Lehane scores for HAVL revealed 91% of attempts having grade 1 views versus 81% for SGVL (OR: 2.5; 95% CI: 0.83, 7.5). Survey data demonstrated participants perceived SGVL as requiring more force to achieve a proper glottic view (27/30) and HAVL as having better glottic views (21/30), increased confidence in passing an endotracheal tube (17/30), better first-pass success (21/30), and being preferred overall (21/30).

Conclusion : Overall, there were no significant differences found between HAVL and SGVL, although providers did seem to subjectively prefer HAVL. The main limitation of the study was its simulation design which can only replicate a rapidly deteriorating HEMS patient to a certain extent. Although the study demonstrated both techniques as suitable for intubation, it is up to the provider’s discretion to select a technique based on preferences, patient’s unique situation and anatomy.