Epidemiology of trauma deaths across a mature regional trauma system: patterns of prehospital and in-hospital fatalities.

Introduction

In mature trauma systems, most trauma deaths occur soon after injury yet studies often only include patients who survive to hospital admission. These studies exclude prehospital deaths and introduce substantial survival bias. Understanding trauma fatalities across all phases of care is essential to identify opportunities to further improve trauma outcomes.

Methods

This retrospective cohort study analysed adult trauma fatalities attended by London's Air Ambulance from 1 January 2019 to 31 December 2020. Deaths were classified as prehospital if traumatic cardiac arrest occurred before hospital arrival. Timing of death was recorded as minutes from injury to arrest for prehospital cases and days from admission to death for in-hospital cases. A multidisciplinary panel determined the likely cause of death using clinical, radiological, and post-mortem findings.

Results

Among 3089 adult trauma patients attended, 497 (16.1%) died. Most deaths (77.1%) occurred prehospital, with a median time from injury to traumatic cardiac arrest of 12 min (i.q.r. 6-24). Haemorrhage and traumatic brain injury accounted for 81.9% of deaths overall, but their distribution differed markedly by phase of care: 96.2% of haemorrhage deaths occurred prehospital, whereas 84.2% of in-hospital deaths were due to traumatic brain injury. In addition, deaths from all other potentially reversible causes, and 95.1% of penetrating trauma deaths, occurred prehospital.

Conclusion

In mature trauma systems, most trauma deaths now occur before arrival in hospital, with many due to potentially reversible causes. The greatest opportunities to improve trauma outcomes now lie in the prehospital phase of care.