Abstract 17874: Effect of Therapeutic Hypothermia with Less Invasive Cardiopulmonary Bypass Hypothermia for Out-of-Hospital Cardiac Arrest

Background: Mild therapeutic hypothermia has been integrated into management strategies for improving the neurological outcome of cardiac arrest with ventricular fibrillation. We introduce our rapid and safe hypothermia procedure with Modified Invasive Cardiopulmonary bypass Hypothermia (LICH) for Return of Spontaneous Circulation (ROSC) patients. This study aimed to evaluate the effects of these new procedures on the outcomes of cardiac arrest patients. Methods: From January 2007 to May 2011, 47 patients were treated with mild hypothermia. These patients were divided into LICH procedure (Group L, N=23) and traditional cold blanket procedure (Group C, N=24) groups. The LICH procedure was indicated for unconscious ROSC patients under 75 years of age with a witness OHCA, and excluded with brain hemorrhage, traumatic cardiac arrest, and any risk of bleeding. Our LICH procedure quickly induced hypothermia via narrow pediatric cannulas on low-perfusion (1 l/min) artery-venous cardiopulmonary bypass (CPB) with minimal anticoagulation. Activated coagulation time (ACT) was set at 150 seconds for the Group L. Any complications, time to target temperature, temperature stability, cytokines and neurological outcomes were compared. A favorable outcome was defined as a Cerebral Performance Category (CPC) of 1-2. Results: There were no significant characteristic differences between groups L and C. As compared with Group L, Group C had higher rates of temperature instability (9% vs. 50%, p=0.021), temperature over-shoot (0% vs. 54%, p=0.001), and quick induction (11 min vs. 307 min, p=0.003). Mortality and serum cytokines level (ΔIL-6, ΔTNF-A) were not seen significant differences in both groups. Addition, a favorable neurological outcome (91% vs. 58%, p=0.017) were seen in Group L. Conclusions: These results indicate that our LICH procedure has the advantages of not only rapid induction for the target temperature, but also less invasive therapy for ROSC patient instead of CPB. In addition, quick induction of mild hypothermia is a great benefit for favorable outcomes.