title: Reliable variables in the exsanguinated patient which indicate damage control and predict outcome.
abstract: BACKGROUND
  Exsanguination as a syndrome is ill defined. The objectives of this study were to investigate the relationship between survival and patient characteristics--vital signs, factors relating to injury and treatment; determine if threshold levels of pH, temperature, and highest estimated blood loss can predict survival; and identify predictive factors for survival and to initiate damage control.
  
  
  METHODS
  A retrospective 6-year study was conducted, 1993 to 1998. In all, 548 patients met one or more criteria: (1) estimated blood loss > or =2,000 mL during trauma operation; (2) required > or =1,500 mL packed red blood cells (PRBC) during resuscitation; or (3) diagnosis of exsanguination. Analysis was made in two phases: (1) death versus survival in emergency department (ED); (2) death versus survival in operating room (OR). Statistical methods were Fisher's exact test, Student's t test, and logistic regression.
  
  
  RESULTS
  For 548 patients, mean Revised Trauma Score 4.38, mean Injury Severity Score 32. Penetrating injuries 82% versus blunt injuries 18%. Vital statistics in emergency department: mean blood pressure 63 mm Hg, heart rate 78 beats per minute. Mean OR pH 7.15 and temperature 34.3 degrees C. Mortality was 379 of 548 (69%). Predictive factors for mortality (means): pH < or =7.2, temperature <34 degrees C, OR blood replacement >4,000 mL, total OR fluid replacement >10,000 mL, estimated blood loss >15 mL/minute (P <0.001). Analysis 1: death versus survival in ED, logistic regression. Independent risk factors for survival: penetrating trauma, spontaneous ventilation, and no ED thoracotomy (P <0.001; probability of survival 0.99613). Analysis 2: death versus survival in OR, logistic regression. Independent risk factors for survival: ISS < or =20, spontaneous ventilation in ED, OR PRBC replacement <4,000 mL, no ED or OR thoracotomy, absence of abdominal vascular injury (P <0.001, max R(2) 0.55, concordance 89%).
  
  
  CONCLUSIONS
  Survival rates can be predicted in exsanguinating patients. "Damage control" should be performed using these criteria. Knowledge of these patterns can be valuable in treatment selection.
authors.affiliation: Trauma Surgery Service "A", Department of Surgery, Division of Trauma and Critical Care, University of Southern California, LAC+USC Medical Center, 1200 N. State St., Rm. 10-750, Los Angeles, CA 90033-4525, USA. asensio@hsc.usc.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Asensio
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authors.lastname: McDuffie
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authors.lastname: Petrone
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authors.lastname: Roldań
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authors.lastname: Gambaro
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authors.lastname: Salim
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authors.lastname: Demetriades
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authors.lastname: Murray
authors.forename: G
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authors.lastname: Velmahos
authors.forename: W
authors.initials: W
authors.lastname: Shoemaker
authors.forename: T V
authors.initials: TV
authors.lastname: Berne
authors.forename: E
authors.initials: E
authors.lastname: Ramicone
authors.forename: L
authors.initials: L
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D001831:Body Temperature; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital; D017707:Erythrocyte Transfusion; D005260:Female; D005440:Fluid Therapy; D006339:Heart Rate; D006470:Hemorrhage / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009873:Operating Rooms; D011379:Prognosis; D012044:Regression Analysis; D012307:Risk Factors