title: Fever after rewarming: incidence of pyrexia in postcardiac arrest patients who have undergone mild therapeutic hypothermia.
abstract: BACKGROUND
  Induction of mild therapeutic hypothermia (TH; temperature 32-34°C) has become standard of care in many hospitals for comatose survivors of cardiac arrest. Pyrexia, or fever, is known to be detrimental in patients with neurologic injuries such as stroke or trauma. The incidence of pyrexia in the postrewarming phase of TH is unknown. We attempted to determine the incidence of fever after TH and hypothesized that those patients who were febrile after rewarming would have worse clinical outcomes than those who maintained normothermia in the postrewarming period.
  
  
  METHODS
  Retrospective data analysis of survivors of out-of-hospital cardiac arrest (OHCA) over a period of 29 months (December 2007 to April 2010).
  
  
  METHODS
  OHCA, age >18, return of spontaneous circulation, and treatment with TH.
  
  
  METHODS
  traumatic arrest and pregnancy. 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 simple descriptive 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 within 24 hours after being rewarmed. Outcome measures included in-hospital mortality as well as neurologic outcome as defined by a dichotomized 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 group had 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).
  
  
  CONCLUSIONS
  Among a cohort of patients who underwent mild TH after OHCA, more than half of these patients developed pyrexia in the first 24 hours after rewarming. Although there were no significant differences in outcomes between febrile and nonfebrile patients identified in this study, these findings should be further evaluated in a larger cohort. Future investigations may be needed to determine whether postrewarming temperature management will improve the outcomes in this population.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA Department of Anesthesia Critical Care, Division of Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, USA mcocchi@bidmc.harvard.edu.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Cocchi
authors.affiliation: Department of Anesthesia Critical Care, Division of Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Myles D
authors.initials: MD
authors.lastname: Boone
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Giberson
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Giberson
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Farrell
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Justin D
authors.initials: JD
authors.lastname: Salciccioli
authors.affiliation: Department of Anesthesia Critical Care, Division of Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Talmor
authors.affiliation: Department of Medicine, Division of Cardiology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Donna
authors.initials: D
authors.lastname: Williams
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA Department of Medicine, Division of Pulmonary Critical Care, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Donnino
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D005260:Female; D005334:Fever / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D006323:Heart Arrest / Q000628:therapy*; D017052:Hospital Mortality; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D017694:Rewarming / Q000009:adverse effects* / Q000401:mortality; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: cardiac arrest; fever; therapeutic hypothermia