Adrenaline for traumatic cardiac arrest: A post hoc analysis of the PARAMEDIC2 trial

Introduction: There is controversy about the effectiveness of adrenaline in traumatic cardiac arrest. This study reports the patient characteristics and outcomes of adults with trauma-related out of hospital cardiac arrest treated with adrenaline or placebo. Methods: This post-hoc, sub-group analysis of the Pre-hospital Randomised Assessment of Adrenaline in Cardiac Arrest-2 (PARAMEDIC-2) trial explored the effect of adrenaline on survival to hospital admission, longer-term survival and neurological outcomes amongst adults with trauma related out of hospital cardiac arrest. Individual patients were randomised through opening a single treatment pack which contained either 10 doses of 1 mg adrenaline or 0.9% saline placebo. Treating clinicians, investigators, outcome assessors and patients were blinded to treatment allocation. The primary outcome was survival to 30 days post cardiac arrest. Results: 123 of 8,014 enrolled patients (1.5%) sustained a traumatic cardiac arrest (66 in the adrenaline arm and 57 in the placebo arm). Three times as many patients were admitted to hospital alive in the adrenaline arm 16/66 (24.2%) compared to 5/56 (8.9%) in the placebo arm, unadjusted odds ratio 3.3 (95% confidence interval 1.1 to 9.6), p = 0.03; adjusted odd ratio 5.6 (95% CI 1.6 to 20.4), p = 0.009. A single patient, in the adrenaline arm, survived beyond 30 days (1/66 (1.5%) compared to 0/57 (0%)), who also experienced a favourable neurological outcome. Conclusion: Adrenaline was associated with a trebling of the rate of survival to hospital admission. These data support the use of adrenaline in trauma related out of hospital cardiac arrest. Registration: ISRCTN73485024.