Prehospital interventions and outcomes in traumatic cardiac arrest: a population-based cohort study using the Danish Helicopter Emergency Medical Services data.

Background and importance: Traumatic cardiac arrest is associated with poor prognosis, and timely evidence-based treatment is paramount for increasing survival rates. Physician-staffed helicopter emergency medical service use in major trauma has demonstrated improved outcomes. However, the sparsity of data highlights the necessity for a comprehensive understanding of the epidemiology of traumatic cardiac arrest.

Objectives: The primary objective of the present study was to evaluate survival and return of spontaneous circulation (ROSC) and to investigate the characteristics of patients with traumatic cardiac arrest assessed by the Danish HEMS.

Design: This was a population-based cohort study based on data from the Danish helicopter emergency medical service database.

Settings and participants: The study included all patients assessed by the Danish helicopter emergency medical services between 2016 and 2021.

Outcome measures and analysis: Data were analysed using descriptive statistics, non-parametric testing and logistic regression analyses. Descriptive analysis of prehospital interventions included cardiopulmonary resuscitation, defibrillation, airway management, administration of blood products, and thoracic decompression. The primary outcome was 30-day survival, and the key secondary outcome was prehospital ROSC.

Main results: A total of 223 patients with TCA were included. The median age was 54 years (IQR 34-68), and the majority were males. Overall, 23% of patients achieved prehospital ROSC, and the 30-day survival rate was 4%. Factors associated with an increased likelihood of ROSC were an initial shockable cardiac rhythm, odds ratio (OR) of 3.78 (95% CI 1.33-11.00) and endotracheal intubation, OR 7.10 (95% CI 2.55-22.85).

Conclusion: This study highlights the low survival rates observed among patients with traumatic cardiac arrest assessed by helicopter emergency medical services. The findings support the positive impact of an initial shockable cardiac rhythm and endotracheal intubation in improving the likelihood of ROSC. The study contributes to the limited literature on traumatic cardiac arrests assessed by physician-staffed helicopter emergency services. Finally, the findings emphasise the need for further research to understand and improve outcomes in this subgroup of cardiac arrest.