Induced hypothermia after cardiac arrest for 12 hours: single-centre experience

Introduction

Induced hypothermia (IH) for 12 to 24 hours is a standard part of post-resuscitation care. We present a cohort of patients with out-of-hospital or in-hospital cardiac arrest (OHCA, IHCA) from our ICU who underwent 12 to 14 hours of IH. Moreover we aimed at neurological outcome in a subgroup of patients with initial ventricular fibrillation (VF) and ST-elevation acute myocardial infarction (STEMI) undergoing coronary intervention (PCI).

Methods

We retrospectively evaluated patients with nontraumatic cardiac arrest admitted to our ICU from 2006 to 2009. A standardised therapeutic protocol including IH was implemented. IH (32 to 34°C) was started within 30 minutes after restoration of spontaneous circulation (ROSC), before PCI, if performed. IH was maintained for 12 to 14 hours, than passive rewarming followed. Endovascular cooling device was not used. Cerebral performance category (CPC) at hospital discharge was evaluated as a main outcome.

Results

Total number of patients was 88 (OHCA n = 63; IHCA n = 25), mean age 57 years, 65% men. ICU mortality was 32% and hospital mortality 53%. Initial ECG rhythm was VF in 59%, asystole in 32% and pulseless electrical activity in 9%. Coronary angiography was performed in 59% and intervention in 41% of all cases. The required target temperature was achieved in 76%. Complications were ventilator-associated pneumonia in 6%, tracheobronchitis in 15% and gastrointestinal bleeding in 2%, no severe bradyarhythmias or iontogram dysbalance was recorded. In a group of 23 patients with VF/STEMI, PCI after initiation of IH was performed. The required target temperature was achieved in 91%. The ICU survival rate was 87% and survival to discharge from hospital was 78%. Good neurological outcome (CPC 1 or 2) in this group at hospital discharge was in 83% (n = 15).

Conclusions

Induced hypothermia has to be started as soon as possible after ROSC. Cooling of patients after cardiac arrest should continue during all therapeutic interventions. Twelve hours of induced hypothermia after cardiac arrest could offer comparable neurological outcomes to 24 hours, especially in the subgroup of patients with VF/STEMI.