Therapeutic Hypothermia for Patients with Out-of-Hospital Cardiac Arrest in North Carolina

Prehospital cooling to improve successful targeted temperature management after cardiac arrest: A randomized controlled trial

RATIONALE

Targeted temperature management (TTM) improves survival with good neurological outcome after out-of-hospital cardiac arrest (OHCA), but is delivered inconsistently and often with delay.

OBJECTIVE

To determine if prehospital cooling by paramedics leads to higher rates of 'successful TTM', defined as achieving a target temperature of 32-34°C within 6h of hospital arrival.

METHODS

Pragmatic RCT comparing prehospital cooling (surface ice packs, cold saline infusion, wristband reminders) initiated 5min after return of spontaneous circulation (ROSC) versus usual resuscitation and transport. The primary outcome was rate of 'successful TTM'; secondary outcomes were rates of applying TTM in hospital, survival with good neurological outcome, pulmonary edema in emergency department, and re-arrest during transport.

RESULTS

585 patients were randomized to receive prehospital cooling (n=279) or control (n=306). Prehospital cooling did not increase rates of 'successful TTM' (30% vs 25%; RR, 1.17; 95% confidence interval [CI] 0.91-1.52; p=0.22), but increased rates of applying TTM in hospital (68% vs 56%; RR, 1.21; 95%CI 1.07-1.37; p=0.003). Survival with good neurological outcome (29% vs 26%; RR, 1.13, 95%CI 0.87-1.47; p=0.37) was similar. Prehospital cooling was not associated with re-arrest during transport (7.5% vs 8.2%; RR, 0.94; 95%CI 0.54-1.63; p=0.83) but was associated with decreased incidence of pulmonary edema in emergency department (12% vs 18%; RR, 0.66; 95%CI 0.44-0.99; p=0.04).

CONCLUSIONS

Prehospital cooling initiated 5min after ROSC did not increase rates of achieving a target temperature of 32-34°C within 6h of hospital arrival but was safe and increased application of TTM in hospital.