Comparison of external and intravascular cooling to induce hypothermia in patients after CPR

Objective: Hypothermia has been shown to reduce neurologic deficits in patients after cardiopulmonary resuscitation (CPR). It was not clear if intravascular cooling is superior to standard external cooling in inducing hypothermia. Goal of this study was to compare intravascular cooling with an automated cooling device with external cooling in everyday practice on a cardiac-care ICU (intensive care unit). Methods: Patients after successful CPR for unwitnessed cardiac arrest were subjected to cooling with an automated cooling system (CoolGard, Alsius) after initial hemodynamic stabilization. Goal was to achieve a core temperature of 33°C. Monitored were the time intervals from admission to begin of cooling and from begin of cooling to target temperature. Data were compared retrospectively with those from patients subjected to external cooling. Results: 31 consecutive patients treated with intravascular cooling were analyzed. Cooling was initiated at a mean time of 58 min after admission, and the target temperature of 33°C was achieved after a mean of 3.48 hours after the begin of cooling. In contrast, 49 patients treated with external cooling achieved a minimum temperature of 34.8°C only 9.2 hours after admission. Conclusion: In everyday practice, intravascular cooling using an automated cooling system is superior for a rapid induction of hypothermia after cardiac arrest.