Factors Associated with Favorable Outcomes in Cardiac Arrest and Target Temperature Management

Current guidelines strongly recommend providing targeted temperature management (TTM) after cardiac arrest, but hypothalamic dysregulation may confound TTM's impact on a patient's ultimate outcome. Although time to reach target temperature has largely been viewed as a process measure for TTM protocols, the difference between initial presenting temperature and target temperature (Δ-temperature) may be a potential surrogate marker of hypothalamic dysregulation. We performed a retrospective observational study to explore whether Δ-temperature was associated with neurologic outcomes and mortality. We included 86 patients (53 with out-of-hospital cardiac arrest [OHCA] and 33 with in-hospital cardiac arrest [IHCA]) in our analysis; more than half of the patients were cooled to 33°C (56.9% in OHCA and 57.6% in IHCA). In univariate logistic regression analysis, Δ-temperature alone did not appear to be statistically associated with mortality or neurologic outcomes regardless of target temperature. In exploratory analysis, longer time from TTM initiation-to-target was associated with worse neurological outcomes in the 33°C target (odds ratio = 0.996, 95% confidence interval = 0.992-1.000). Further research investigating the impact of hypothalamic dysregulation and Δ-temperature as well as the rate of cooling may be warranted to elucidate additional factors contributing to outcomes after cardiac arrest. In addition, our study population was noted to have a higher proportion of Asians and Native Hawaiians/Pacific Islanders, with a potential disparity in outcomes. Future studies may be warranted to ensure generalizability of TTM protocols and findings across populations.