Abstract 2507: “Cool It”: Therapeutic Hypothermia for Recovery of Neurologic Function in High Risk Patients Following Cardiac Arrest
Background: Survival to discharge following out-of-hospital cardiac arrest (OOHCA) is uncommon. Among survivors, neurologic deficits from anoxic encephalopathy are common and disabling. The Hypothermia after Cardiac Arrest (HACA) Study Group reported that pts randomized to therapeutic hypothermia (TH) had improved survival (59% vs. 45%; p=0.02) and neurologic outcome (55% vs. 39%; p=0.009).
Methods: OOHCA pts due to ventricular fibrillation, ventricular tachycardia, asystole, and pulseless electrical activity (PEA) were cooled to 33°C for 24 hrs. Pts in cardiogenic shock were included. Cerebral function after TH was measured by the five point Pittsburgh Cerebral Performance Category (CPC) scale. CPC 1 and 2 are positive neurologic outcomes, 3 and 4 are poor outcomes, and 5 is death.
Results: From 2/06 to 4/09, 122 pts were treated with TH, and 71 (58%) of pts survived. Applying the HACA Study Group exclusion criteria eliminated 60 pts with cardiogenic shock or PEA/asystole rhythms. HACA criteria pts had a higher survival rate than non-HACA criteria pts (77% vs. 38%; p=0.001). Comparing HACA Study Group survivors with all Cool It survivors, 24% vs. 8.5% were discharged with poor neurologic outcomes, CPC 3 or 4.
Conclusion: In comparison to previous studies, the Cool It protocol extended TH to higher risk pts and discharged pts with higher neurologic outcomes. Cool It enhanced survival in HACA criteria pts with rapid treatment and preserved neurologic and functional status in a broader pt population.