title: Prehospital hypotension redefined.
abstract: BACKGROUND
  The American College of Surgeons Committee on Trauma suggests prehospital systolic blood pressure (PSBP) < 90 mm Hg as a criterion for triage of injured patients to trauma centers. However, Advanced Trauma Life Support recognizes this threshold as a late sign of shock. We undertook the current study to determine whether a higher PSBP threshold may identify patients at significant risk of death.
  
  
  METHODS
  A retrospective analysis of an urban, Level I trauma center registry data was undertaken in patients with complete information on PSBP (n = 16,365; 1994-2003). Several thresholds of PSBP were chosen: < or = 60, < or = 70, < or = 80, < or = 90, < or = 100, and < or = 110 mm Hg, and the relationship between each threshold of PSBP and patient outcomes was explored. A p value < 0.05 was considered statistically significant.
  
  
  RESULTS
  Mean age of patients was 36 +/- 16 years, and 81% sustained a blunt injury. PSBP strongly correlated with systolic blood pressure obtained in the emergency department (Pearson r 0.65, p < 0.001). The risk of death increased sharply when PSBP dropped < 110 mm Hg, with nearly 1 in 10 (8%) dying in the emergency department and one in six (15%) dying eventually.
  
  
  CONCLUSIONS
  The definition of prehospital hypotension used for triage of injured patients to trauma centers should be redefined as PSBP < 110 mm Hg. The impact of this redefinition on trauma center resource utilization should be studied further.
authors.affiliation: Department of Surgery, Division of Burns, Trauma, and Critical Care, University of Texas Southwestern Medical School, Parkland Memorial Hospital, Dallas, Texas, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Bruns
authors.forename: Larry
authors.initials: L
authors.lastname: Gentilello
authors.forename: Alan
authors.initials: A
authors.lastname: Elliott
authors.forename: Shahid
authors.initials: S
authors.lastname: Shafi
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007022:Hypotension / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000628:therapy; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000150:complications / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D012306:Risk; D012307:Risk Factors; D012769:Shock / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000628:therapy; D016019:Survival Analysis; D013781:Texas; D014193:Trauma Centers; D014218:Triage; D014949:Wounds, Nonpenetrating / Q000150:complications / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D055815:Young Adult