Effect of different combinations of initial body temperature and target temperature on neurological outcomes in out-of-hospital cardiac arrest patients treated with targeted temperature management

Abstract

We hypothesized that different combinations of initial and target temperatures during targeted temperature management (TTM) may be associated with neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors. Adult patients with OHCA who underwent TTM were enrolled. The study participants were divided into four groups: lower initial body temperature and lower target temperature (Low-Low group), lower initial body temperature and higher target temperature (Low-High group), higher initial body temperature and lower target temperature (High-Low group), and higher initial body temperature and higher target temperature (High-High group). Initial body temperature was dichotomized based on the median value (35.6 ◦C) as a cutoff, and the target temperature was dichotomized with a target temperature of 34 ◦C as a cutoff. The primary outcome was defined as a favorable 28-day neurological outcome. In total, 231 patients were included in the analysis, and 74 (32.0%), 43 (18.6%), 82 (35.5%), and 32 (13.9%) patients were classified into the Low-Low, Low-High, High-Low, and High-High groups, respectively. The proportion of patients with favorable 28-day neurological outcomes differed among the study groups (Low-Low, 14 (18.9%); Low-High, 7 (16.3%); High-Low, 37 (45.1%); High-High, 11 (34.4%); p = 0.001). In the multivariable analysis, the Low-High group was independently associated with a less favorable 28-day neurological outcome compared to the High-Low group (adjusted odds ratio, 0.22; 95% confidence interval, 0.06–0.91; p = 0.036). In conclusion, higher initial body temperature and lower target temperature during TTM were independently associated with a more favorable 28-day neurological outcome compared to the lower initial body temperature and higher target temperature in patients resuscitated from OHCA of medical etiology.