Abstract 12734: Cooling Duration and Rewarming Speed in Therapeutic Hypothermia for Out-of-hospital Cardiac Arrests: How Should We Combine the Protocols?
Background: Therapeutic hypothermia (TH) improves outcomes of patients with out-of-hospital cardiac arrest (OHCA). However, how we should combine cooling protocol and rewarming protocol to maximize TH protection remains unclear. In this study, relationships between cooling duration (CD), rewarming speed (RWSD), and neurological outcomes in patients with OHCA were examined by use of data in the multicenter registry of OHCA treated with TH in Japan (J-Pulse-Hypo registry).
Methods: Data from 452 patients were submitted to J-Pulse-Hypo registry from 2005 to 2009, but 73 patients lacked data of sequential deep body temperature. Thus, 397 patients were included in the present study and retrospectively divided into the four groups according to CD and RWSD: 50 patients with CD ≤24 hours and RWSD ≥ 2.0 °C / day (Short-Rapid, SR group), 51 patients with CD > 24 hours and RWSD 2.0 ≥ °C / day and (Long-Rapid, LR group), 124 patients with CD ≤ 24 hours and RWSD < 2.0 °C/ day and (Short-Slow, SS group) and 154 patients with CD > 24 hours and RWSD < 2.0 °C/ day and (Long-Slow, LS group). Favorable neurological outcome was defined as cerebral performance category 1 or 2.
Results: There was no significant inter-group difference regarding gender, age, and percentages of presence of bystanders, bystander cardiopulmonary resuscitation and ventricular fibrillation in initial ECG, incidence of return of spontaneous circulation before admission and time needed to reach target temperature after the onset of cooling. However, LR group was less treated with IABP compared with the other groups (44.0% for SR, 23.5% for LR, 31.5% for SS, 50.0% for LS, p<0.001). Although the survival rate at 30 days was not statistically different in all four groups, the rate of favorable neurological outcomes was significantly higher in LR group than in the other groups (Figure 1).
Conclusion: These results suggest that CD > 24 hours and RWSD 2.0 ≥ °C/ day is an appropriate combination of cooling and rewarming protocols.
- © 2011 by American Heart Association, Inc.