Abstract 210: The Association of Body Mass Index with Time to Target Temperature and Outcomes in Postarrest Patients Treated with Therapeutic Hypothermia via an External Cooling System
Background: Regarding the use of TH for post-cardiac arrest patients, preliminary evidence suggests that more rapid attainment of target temperature (32-34oC) may improve outcomes. We hypothesized that the time to achieve target temperature is increased as Body Mass Index (BMI) increases and that this may impact clinical outcomes.
Objective: To assess for an association of BMI with time to target temperature, skin complications, survival to hospital discharge, and good neurologic outcome (GCS 14-15) in survivors.
Methods: Single-center retrospective cohort of cardiac arrest patients who underwent TH using an external cooling system between 7/2007 - 6/2012. We examined the association between BMI (weight in kilograms divided by height in meters squared) and time from initiation of cooling to attainment of target temperature. The cohort was categorized into two groups based on their BMI, (see table 1). The Wilcoxon rank-sum was used to compare time to target temperature by BMI status, categorized as obese and non-obese and the chi-squared was used to compare categorical variables.
Results: Of the 179 patients treated with TH, 135 were evaluable. The median age of the cohort was 60 yrs, (IQR 46, 69); 64/135 (47%) were female and 37/135 (27%) had VF/VT as the initial rhythm. Mean time to target temperature was 216 min (IQR 135, 359). Obese compared to non-obese patients required a longer time to achieve target temperature (p=0.07) and obese patients were significantly more likely to have skin breakdown (p=0.01). There was no survival difference between obese and non-obese patients in terms of discharge (53% vs. 45%, p=0.39), nor good neurologic outcome (76% vs. 62%, p=0.26).
Conclusions: Obese patients were significantly more likely to experience skin breakdown as a result of TH. There was a suggestion that time to target temperature was prolonged in obese patients. Whether outcomes could have been improved in obese patients if time to target temperature was reduced, is unknown.
- © 2012 by American Heart Association, Inc.