Temperature Variation After Rewarming from Deep Hypothermic Circulatory Arrest Is Associated with Survival and Neurologic Outcome

Therapeutic hypothermia is recommended by international guidelines after cardio-circulatory arrest. However, the effects of different temperatures during the first 24 hours after deep hypothermic circulatory arrest (DHCA) for aortic arch surgery on survival and neurologic outcome are undefined. We hypothesize that temperature variation after aortic arch surgery is associated with survival and neurologic outcome. In the period 2010-2014, a total of 210 consecutive patients undergoing aortic arch surgery with DHCA were included. They were retrospectively divided into three groups by median nasopharyngeal temperature within 24 hours after rewarming: hypothermia (<36 degrees C; n=65), normothermia (36-37 degrees C; n=110), and hyperthermia (>37 degrees C; n=35). Multivariate stepwise logistic and linear regressions were performed to determine whether different temperature independently predicted 30-day mortality, stroke incidence, and neurologic outcome assessed by cerebral performance category (CPC) at hospital discharge. Compared with normothermia, hyperthermia was independently associated with a higher risk of 30-day mortality (28.6% vs. 10.9%; odds ratio [OR] 2.8; 95% confidence interval [CI], 1.1-8.6; p=0.005), stroke incidence (64.3% vs. 9.1%; OR 9.1; 95% CI, 2.7-23.0; p=0.001), and poor neurologic outcome (CPC 3-5) (68.8% vs. 39.6%; OR 4.8; 95% CI, 1.4-8.7; p=0.01). No significant differences were demonstrated between hypothermia and normothermia. Postoperative hypothermia is not associated with a better outcome after aortic arch surgery with DHCA. However, postoperative hyperthermia (>37 degrees C) is associated with high stroke incidence, poor neurologic outcome, and increased 30-day mortality. Target temperature management in the first 24 hours after surgery should be evaluated in prospective randomized trials.