Prehospital advanced airway management in the Nordic countries

Tracheal intubation (TI) is often the preferred technique to secure the airway of an unconscious patient in the prehospital setting. Prehospital TI is associated with several challenges, including limited assistance, few airway rescue devices and environmental difficulties. An example of the latter is the occasional need for TI inside the cabin of an ambulance helicopter. The Nordic countries consist of both rural and urban areas with typically cold subarctic climate. The region is characterized by almost exclusive use of airway experts, mainly anaesthetists, for prehospital TI. The overall aim was to investigate prehospital advanced airway management in Nordic countries with regard to success rates, times, providers and techniques.

Study I: A retrospective observational study of all patients intubated out-of-hospital with the device Airtraq® in Stockholm 2008-2012. A total number of 2453 patients were intubated during the study period and Airtraq® was used in 28 (1.1%) cases. Sixty-eight percent (19/28) of the Airtraq® intubation attempts were successful. When used due to an anticipated or unexpected difficult airway, the success rate was 61% (14/23).

Study II: An experimental prospective randomized crossover manikin study on anaesthetist TI was conducted in a military helicopter cabin in daylight or darkness with night vision goggles (NVG) or in a daylight emergency department (ED) setting. The TI success rate was 100% in all scenarios. The in-cabin helicopter TI time was shorter in daylight vs. darkness with NVG (16.5 s vs. 30.0 s; p=0.03). There was no difference in TI time between the helicopter cabin daylight and ED setting (16.5 vs. 16.8 s; p=0.91). There was no difference in either glottic visualization (CL 2.0 vs. 1.8; p=0.72) or perceived intubation difficulty (VAS 3.0 vs. 2.8; p=0.24) between the daylight helicopter and ED scenarios.

Study III: A prospective observational study of advanced airway management by twelve second-tier prehospital critical care teams in the Nordic countries was conducted from May 2015 to November 2016. Data were collected from six ambulance helicopters and six rapid response cars using the standardized Utstein-style airway template. During the study period, 2028 patients were intubated due to cardiac arrest (53.0%), other medical conditions (26.3%) and trauma (19.1%). The majority (67.0%) of the TIs were performed by providers who had intubated >2500 patients. The overall TI success rate was 98.7%, with a first pass success rate of 84.5% and overall complication rate of 10.9%. The median TI time was 25 s (IQR 15-30 s), and the time on scene was 25 min (IQR 18-33 min). The TI success rate was higher among physicians compared with nurses (99.0% vs. 97.6%; p=0.03).

Study IV: An experimental prospective randomized crossover manikin study of in-cabin vs. outside helicopter cabin TI was conducted by 14 anaesthetists. The success rate was 100%, with all TIs being successful on the first attempt. There was no difference in glottic visualization (CL 1.0 vs. 1.0), but the participants perceived the in-cabin TI to be easier than intubating outside the helicopter cabin (VAS 1 vs. VAS 2; p=0.02). The total on-scene time was significantly shorter using the in-cabin TI strategy compared with the standard outside TI (266 vs. 320 s; p=0.04).

In conclusion, prehospital TI is almost exclusively performed by very experienced airway providers in the Nordic countries. In this setting, the prehospital TI success rate is high and associated with few complications, comparable to in-hospital standards. The TI procedure is fast with a short on-scene time, which may benefit patients with time-critical emergencies, such as multitrauma and traumatic brain injuries. There may be potential to further decrease on-scene times with the in-cabin TI concept. The first-pass TI success rate was higher with video laryngoscopy compared with direct laryngoscopy, but the Airtraq® is not a suitable prehospital indirect laryngoscope. There is a need for large randomized studies to better investigate different aspects of the prehospital advanced airway management.

List of scientific papers

I. Use of the Airtraq device for airway management in the prehospital setting – a retrospective study. Gellerfors M, Larsson A, Svensén S, Gryth D. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2014; 22:10: 1-6.
https://doi.org/10.1186/1757-7241-22-10

II. Endotracheal Intubation With and Without Night Vision Goggles in a Helicopter and Emergency Room Setting: A Manikin Study. Gellerfors M, Christer Svensén, Linde J, Lossius HM, Gryth D. Military Medicine. 2015; 180(9): 1006-1010.
https://doi.org/10.7205/MILMED-D-14-00583

III. Pre-hospital advanced airway management by anaesthetist and nurse anaesthetist critical care teams: A prospective observational study of 2,028 prehospital tracheal intubations. Gellerfors M, Fevang E, Bäckman A, Krüger A, Mikkelsen S, Nurmi J, Rognås L, Sandström E, Skallsjö G, Svensén C, Gryth D, Lossius HM. British Journal of Anaesteshesia. 2018; 120(5): 1103-1109.
https://doi.org/10.1016/j.bja.2017.12.036

IV. Prehospital tracheal intubation outside and inside the ambulance helicopter cabin: a prospective randomised cross-over manikin study. Kornhall D, Gellerfors M, Näslund R, Lind F, Broms J, Helliksson F. [Accepted]