Abstract 151: Obesity and Cooling Time to Target Temperature in Patients Undergoing Therapeutic Hypothermia After Out-of-Hospital Cardiac Arrest
Introduction: Therapeutic hypothermia (TH) is an important treatment to improve neurologic outcome in victims of out-of-hospital cardiac arrest (OHCA). It has been shown that shorter times to target temperature result in better outcomes. The purpose of this study is to evaluate the effect of obesity, on cooling times when providing TH.
Methods: This study was set at a tertiary care cardiac receiving hospital that has an active, structured TH program for patients with OHCA. The facility receives post-OHCA patients both directly from the scene and on inter-facility transfer. We included all patients that received TH after OHCA. Obesity was defined as BMI > 30. Cooling time was defined as time from initiating cooling to attaining target temperature of 34 degrees Celsius. An existing TH database was queried from 2/1/2009 to 2/29/2012 and identified 169 patients. After excluding patients without sufficient data to calculate BMI and those undergoing immersion cooling (not available to all patients in the dataset), 151 patients remained. Analysis was conducted using Kruskal-Wallis non-parametric test and Pearson’s Chi-Squared test as appropriate.
Results: Of the 151 patients, 84 were categorized as obese. The median cooling time for obese patients was 243 minutes (IQR 153, 435) and non-obese patients was 165 minutes (IQR 108, 303) and p-value of 0.012.
Conclusion: When providing therapeutic hypothermia for patients after cardiac arrest, obesity is associated with a significant increase in the time to reach target body temperature. Further study is needed to assess the implications of this finding on patient outcome and to evaluate if any association between obesity and lability of body temperature during maintenance of cooling and rewarming phases of TH. Additionally, obese patients potentially represent a population where additional approaches may be needed to improve cooling times.
- © 2012 by American Heart Association, Inc.