Fever after rewarming: Incidence of pyrexia in postcardiac arrest patients who have undergone mild therapeutic hypothermia

摘要

Background: Induction of mild therapeutic hypothermia (TH; temperature 32-34-C) has become standard of care in manyhospitals for comatose survivors of cardiac arrest. Pyrexia, or fever, is known to be detrimental in patients with neurologicinjuries such as stroke or trauma. The incidence of pyrexia in the postrewarming phase of TH is unknown. We attempted todetermine the incidence of fever after TH and hypothesized that those patients who were febrile after rewarming would haveworse clinical outcomes than those who maintained normothermia in the postrewarming period.Methods: Retrospective dataanalysis of survivors of out-of-hospital cardiac arrest (OHCA) over a period of 29 months (December 2007 to April 2010). Inclusioncriteria: OHCA, age >18, return of spontaneous circulation, and treatment with TH. Exclusion criteria: traumatic arrest andpregnancy. Data collected included age, sex, neurologic outcome, mortality, and whether the patient developed fever (temperature> 100.4-F, 38-C) within 24 hours after being fully rewarmed to a normal core body temperature after TH. We used simpledescriptive statistics and Fisher exact test to report our findings.Results: A total of 149 patients were identified; of these, 82(55%) underwent TH. The mean age of the TH cohort was 66 years, and 28 (31%) were female. In all, 54 patients survived for>24 hours after rewarming and were included in the analysis. Among the analyzed cohort, 28 (52%) of 54 developed fever within24 hours after being rewarmed. Outcome measures included in-hospital mortality as well as neurologic outcome as defined by adichotomized Cerebral Performance Category (CPC) score. When comparing neurologic outcomes between the groups, 16(57%) of 28 in the postrewarming fever group had a poor outcome (CPC score 3-5), while 15 (58%) of 26 in the no-fever grouphad a favorable outcome (P =.62). In the fever group, 15 (52%) of 28 died, while in the no-fever group, 14 (54%) of 26 died(P =.62).Conclusion: Among a cohort of patients who underwent mild TH after OHCA, more than half of these patients developedpyrexia in the first 24 hours after rewarming. Although there were no significant differences in outcomes between febrileand nonfebrile patients identified in this study, these findings should be further evaluated in a larger cohort. Future investigationsmay be needed to determine whether postrewarming temperature management will improve the outcomes in this population.