Manual versus Automated Ventilation with an i-gel^® Airway During Short-Haul Helicopter Operations

Short-haul rescue involves evacuating a patient from a backcountry environment while suspended beneath a helicopter. Airway management may be required for head injuries or other critical transports. These missions may compromise airway security and ventilation quality. The objective of this study was to compare manual and automated ventilation performance during simulated static and live short-haul scenarios using a mid-fidelity manikin with an i-gel^® airway.

We used a prospective simulation-based, non-randomized crossover study design. The study included two scenarios: simulated static and live helicopter short-haul scenarios. An i-gel^® airway was pre-inserted into a mid-fidelity Laerdal Quality Cardiopulmonary Resuscitation manikin. The primary outcome was achievement of target minute ventilation (MV; 5-7.2 L/min). Stretcher attendants performed two short-haul tests for each scenario. The first test utilized a pocket bag-valve-mask for manual ventilation (MV) of the manikin and for the second an automatic ventilator was used. Tidal volumes, breaths per minute, and MV were measured. Additionally, post-test i-gel^® movement was documented and each stretcher attendant completed a post-simulation operational usability survey. Paired comparisons between manual and automated ventilation were analyzed using McNemar's exact test for the primary outcome and Wilcoxon signed-rank tests for secondary outcomes.

Nine attendants completed both methods in the static scenario; six completed both in the live scenario. Target MV was achieved in 67% of tests via MV compared to 100% with automated during the static tests. In live scenarios, target MV was achieved via manual in 33% of tests while automated achieved 100%. This difference, while substantial, did not reach statistical significance (static: p = 0.25; live: p = 0.12) likely due to low number of tests with all discordant outcomes favoring the automated ventilator. Manual ventilation resulted in greater i-gel^® movement and resulted in four ventilation disconnects (two static, two live) while no disconnects were observed during automated ventilation; participants also reported greater preference for automated ventilation.

Automated ventilation consistently achieved target MV, minimized i-gel^® movement and was preferred by attendants. Rescue teams should consider automated ventilation for short-haul airway management with an i-gel^® airway.