IMPORTANCE: Traumatic cardiac arrest (TCA) presents a critical challenge in trauma care, often occurring rapidly after injury before effective interventions are available. OBJECTIVE: To evaluate the association of prehospital resuscitative thoracotomy with survival outcomes for TCA. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study examined all cases of prehospital resuscitative thoracotomy for TCA in London from January 1999 to December 2019. Data were analyzed from July 2022 to July 2023. EXPOSURE: Prehospital resuscitative thoracotomy for TCA. MAIN OUTCOMES AND MEASURES: The primary outcome was survival to hospital discharge. Secondary outcomes included survival to hospital admission and neurological status at discharge. RESULTS: Prehospital resuscitative thoracotomy was undertaken in 601 patients with out-of-hospital TCA. The median (IQR) age was 25 (20-37) years
538 (89.5%) were male and 63 (10.5%) female. A total of 529 patients (88.0%) had a penetrating mechanism of injury. TCA occurred at a median (IQR) of 12 (6-22) minutes after the emergency call, with 491 arrests (81.7%) before the advanced trauma team's arrival. TCA was the result of cardiac tamponade (105 patients, 17.5%), exsanguination (418 patients, 69.6%), and exsanguination combined with cardiac tamponade (72 patients, 12.0%). Thirty patients (5.0%) survived to hospital discharge, with a favorable neurological outcome observed in 23 survivors (76.6%). Survival varied significantly with the cause of TCA: 22 of 105 patients (21%) with cardiac tamponade, 8 of 418 patients (1.9%) with exsanguination, and none of the 72 patients with combined or other pathologies survived. There were no survivors beyond 15 minutes of TCA for cardiac tamponade and 5 minutes after exsanguination. Multivariable analysis revealed that the cause of TCA (adjusted odds ratio [aOR], 21.1
95% CI, 8.1-54.7
P <
.001), duration of TCA (aOR, 20.9
95% CI, 4.4-100.6, P <
.001), and absence of the need for internal cardiac massage (AOR, 0.2
95% CI, 0.06-0.5
P = .001) were independently associated with survival. CONCLUSIONS AND RELEVANCE: TCA occurs soon after injury, with only a brief window available for effective intervention. This study found that resuscitative thoracotomy is feasible in a mature, physician-led, urban prehospital system and is associated with improved survival for patients with out-of-hospital TCA, particularly when caused by cardiac tamponade, in situations where other treatment options are limited.