Airway Management Difficulties in a Helicopter Emergency Medical Service (HEMS): A Retrospective Observational Study of 676 Out-of-Hospital Intubations

Abstract

Background: Airway management is a key skill in any helicopter emergency medical service (HEMS). Successful intubation is less often than in the hospital, and alternative forms of airway management are needed more often. Methods: Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patients charts from all scene calls (n=9035) that took place between June 2016 and May 2017 (12 months) were analysed. The primary outcome parameter was intubation success rate. Secondary parameters included number of patients intubated by ground-based emergency medical services, alternative devices used, and comparison of patients with and without difficulties in airway management. Results: A total of 676 patients with invasive ventilatory support were identified. Difficulties in airway management were rare, occurring in 44 (6.5%) patients, and trauma was significantly more common (59.1% vs. 38.6%, p<0.001). In 335 (49.6%) patients, advanced airway management had already been initiated by Ground emergency medical services upon arrival of the HEMS. Paramedics had significantly more exposure to patients needing prehospital anaesthesia than the HEMS physicians; median 12 (IQR 9 to 17.5) versus 3 (IQR 2 to 6), p<0.001.Conclusion: Despite overall high success rates for endotracheal intubation in the physician-staffed service, each physician gets little real-life experience with advanced airway management in the field, highlighting the importance of a solid basic competence such as anaesthesiology and additional training. Direct laryngoscopy is still a valuable skill and an important Plan B in difficult airway situations in which factors such as fogging, blood, bright radiation on the video laryngoscopes screen, impaired the success of video laryngoscopes intubation.