title: Hypotensive resuscitation during active hemorrhage: impact on in-hospital mortality.
abstract: BACKGROUND
  Traditional fluid resuscitation strategy in the actively hemorrhaging trauma patient emphasizes maintenance of a normal systolic blood pressure (SBP). One human trial has demonstrated improved survival when fluid resuscitation is restricted, whereas numerous laboratory studies have reported improved survival when resuscitation is directed to a lower than normal pressure. We hypothesized that fluid resuscitation titrated to a lower than normal SBP during the period of active hemorrhage would improve survival in trauma patients presenting to the hospital in hemorrhagic shock.
  
  
  METHODS
  Patients presenting in hemorrhagic shock were randomized to one of two fluid resuscitation protocols: target SBP > 100 mm Hg (conventional) or target SBP of 70 mm Hg (low). Fluid therapy was titrated to this endpoint until definitive hemostasis was achieved. In-hospital mortality, injury severity, and probability of survival were determined for each patient.
  
  
  RESULTS
  One hundred ten patients were enrolled over 20 months, 55 in each group. The study cohort had a mean age of 31 years, and consisted of 79% male patients and 51% penetrating trauma victims. There was a significant difference in SBP observed during the study period (114 mm Hg vs. 100 mm Hg, p < 0.001). Injury Severity Score (19.65 +/- 11.8 vs. 23.64 +/- 13.8, p = 0.11) and the duration of active hemorrhage (2.97 +/- 1.75 hours vs. 2.57 +/- 1.46 hours, p = 0.20) were not different between groups. Overall survival was 92.7%, with four deaths in each group.
  
  
  CONCLUSIONS
  Titration of initial fluid therapy to a lower than normal SBP during active hemorrhage did not affect mortality in this study. Reasons for the decreased overall mortality and the lack of differentiation between groups likely include improvements in diagnostic and therapeutic technology, the heterogeneous nature of human traumatic injuries, and the imprecision of SBP as a marker for tissue oxygen delivery.
authors.affiliation: R Adams Cowley Shock Trauma Center and the Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. rdutton@umaryland.edu
authors.forename: Richard P
authors.initials: RP
authors.lastname: Dutton
authors.forename: Colin F
authors.initials: CF
authors.lastname: Mackenzie
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Scalea
mesh_terms: D000328:Adult; D001794:Blood Pressure; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D017052:Hospital Mortality; D006801:Humans; D007022:Hypotension / Q000628:therapy*; D015601:Injury Severity Score; D007902:Length of Stay; D008297:Male; D012151:Resuscitation / Q000379:methods*; D012771:Shock, Hemorrhagic / Q000401:mortality / Q000628:therapy*; D015996:Survival Rate; D014949:Wounds, Nonpenetrating / Q000401:mortality / Q000628:therapy*