Military Forward Aeromedical Evacuation and civilian Helicopter Emergency Medical Services are widely used to conduct Primary Aeromedical Retrieval. Crew composition in Primary Aeromedical Retrieval missions varies considerably. The ideal composition is unknown. Thus, we conducted a descriptive systematic review on mortality and other outcomes for different Primary Aeromedical Retrieval crew compositions.

Medline, Embase, and Cochrane Controlled Trials Register were searched up to January 2020. Results were reported per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Studies of adult trauma air transported by different crews were included. Population, injury severity, crew composition, procedures, and outcomes, including mortality, were abstracted. Risk of bias was assessed using previously validated tools. A lack of reported effect measures precluded a quantitative analysis.

Sixteen studies met inclusion criteria (3 prospective studies, 1 case-control, and 12 retrospective). Overall, studies reported a mortality benefit associated with advanced health care providers. This was most apparent in patients with severe but survivable injuries. In this population, early rapid sequence induction, endotracheal intubation, mechanical ventilation, thoracostomies, blood products transfusion, and treatment of hemorrhagic shock are better performed by advanced providers and may improve outcomes. The quality of evidence reported a moderate risk of bias in the included studies.

Overall, findings were divergent but showed a trend to decreased mortality in patients treated by advanced providers with interventions beyond the basic paramedic level. This trend was most significant in patients with severe but survivable injuries. These results should be cautiously interpreted because most studies were observational, had small sample sizes, and had a high potential for confounding factors.