Impact of prehospital hypothermia on transfusion requirements and outcomes.

BACKGROUND: Prehospital hypothermia (PH) is known to increase mortality following traumatic injury. PH relationship with transfusion requirements has not been documented. The purpose of this investigation was to analyze the impact of PH on blood product requirements and subsequent outcomes.
METHODS: The Los Angeles County Trauma System Database was queried for all patients admitted between 2005 and 2009. Demographics, physiologic parameters, and transfusion requirements were obtained and dichotomized by admission temperatures with a core temperature of less than 36.5 °C considered hypothermic. Multivariate analysis was performed to determine factors contributing to transfusion requirements and to derive adjusted odds ratios (AORs) for mortality and rates of adult respiratory distress syndrome and pneumonia.
RESULTS: A total of 21,023 patients were analyzed in our study with 44.6% presenting with PH. Hypothermic patients required 26% more fluid resuscitation (p < 0.001) in the emergency department and 17% more total blood products (p < 0.001) than those who were admitted with a normal temperature. There was a trend toward an increase in emergency department transfusion (8%, p = 0.06). PH was independently associated with the need for a transfusion (AOR, 1.1; p = 0.047), increased mortality (AOR, 2.0; p < 0.01), as well as incidence of adult respiratory distress syndrome (AOR, 1.8; p < 0.05) and pneumonia (AOR, 2.6; p < 0.01).
CONCLUSION: PH is associated with increased transfusion and fluid requirements and subsequently worse outcomes. Interventions that correct hypothermia may decrease transfusion requirements and improve outcomes. Prospective studies investigating correction of hypothermia in trauma patients are warranted. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.