Abstract 91: Influence of Early Return of Spontaneous Circulation and Early Induction of Cooling on Neurological Outcome in Patients Treated with Therapeutic Hypothermia After Out-of-Hospital Shockable Cardiac Arrest
BACKGROUND Therapeutic hypothermia is a helpful therapeutic approach in patients who remain comatose after return of spontaneous circulation (ROSC). However, optimal time window for therapeutic hypothermia have not been known. We hypothesized that early achievement of ROSC and early induction of therapeutic hypothermia would be associated with favorable outcome.
METHODS The J-PULSE-Hypo was conducted a multi-center registry to investigate the effects of therapeutic hypothermia. In this study, we investigated the relationship between neurological outcome at hospital discharge and time intervals from collapse to ROSC and from ROSC to induction of cooling. We constructed a receiver-operating-characteristics (ROC) curve to illustrate the various cutoff values of those time intervals.
RESULTS Of the 452 unconscious patients who were treated with hypothermia after out-of-hospital cardiac arrest due to cardiac etiology, 301 who were cooled from 32°C to 34 °C after witnessed shockable cardiac arrest were included. The cutoff value for identification of favorable outcome was 28.5 minutes in the collapse-to-ROSC interval and 48.0 minutes in the ROSC-to-cooling interval. Significant difference was seen in favorable outcome among the 4 groups of patients who were classified according to those cutoff values (81% in group 1 of collapse-to-ROSC interval≤28 minutes and ROSC-to-cooling≤48 minutes, 78% in group 2 of collapse-to-ROSC interval≤28 minutes and ROSC-to-cooling>48 minutes, 46% in group 3 of collapse-to-ROSC interval>28 minutes and ROSC-to-cooling≤48 minutes, and 36% in group 4 of collapse-to-ROSC interval>28 minutes and ROSC-to-cooling>48 minutes, p<0.0001). In a logistic-regression model in which we adjusted for other independent predictors, those 4 groups remained associated with neurological outcome. The adjusted odds ratio for favorable outcome among those 4 groups was 10.8 (95%CI, 4.5-18.5) in groups 1, 8.5 (95%CI, 3.6-20.1) in group 2 and 2.0 (95%CI, 0.85-4.6) in group 3.
CONCLUSION Early achievement of ROSC was associated with favorable outcome, but early induction of cooling did not influence on neurological outcome in unconscious patients treated with therapeutic hypothermia after out-of-hospital shockable cardiac arrest.
- © 2011 by American Heart Association, Inc.