Therapeutic Hypothermia May Improve Neurological Outcomes in Extracorporeal Life Support for Adult Cardiac Arrest

Limited data exists on patients receiving therapeutic hypothermia during extracorporeal life support (ECLS). We investigated outcomes and prognostic factors in these patients.

A retrospective review was conducted for 225 consecutive adult patients treated with ECLS between July 2003 and January 2016. Extracorporeal life support was initiated for refractory cardiac arrest (>10 mins) in 79 patients (35.1%). Patient demographics, ECLS-related complications, in-hospital mortality and neurological outcomes were analysed.

The mean age was 49.9±12.4 years. Sixty-two patients (78.5%) were male. The mean duration of CPR and ECLS were respectively, 32.0±23.3 mins and 5.4±4.0 days. Therapeutic hypothermia (34^oC) was maintained for 24hours in 14 patients (17.7%). Thirty-five patients (44.3%) were weaned off ECLS. Twenty-one patients (26.6%) survived to hospital discharge with 16 (20.3%) recovering good neurological function. Compared to ECLS at normothermia, neurologically favourable survival was higher in the hypothermia group (42.9% vs 15.4%, p=0.020). Multivariable analysis identified a non-shockable rhythm [odds ratio (OR) 5.1, confidence interval (CI) 1.5-16.8], ischaemic hepatitis (OR 6.2, CI 1.1-33.6) and hypoxic ischaemic encephalopathy (OR 5.1, CI 1.5-17.1) as predictors of in-hospital mortality. Therapeutic hypothermia (OR 4.9, CI 1.2-20.4) and acute renal failure (OR 0.19, CI 0.05-0.70) were predictors of neurologically favourable survival.

In this report of patients treated with ECLS, in-hospital survival and survival with good neurological performance were 26.6% and 20.3% respectively. A non-shockable rhythm, ischaemic hepatitis and hypoxic ischaemic encephalopathy were predictors of in-hospital mortality. Therapeutic hypothermia during ECLS was associated with improved neurological outcomes.