title: Lactate predicts massive transfusion in hemodynamically normal patients.
abstract: Trauma patients at risk of deterioration because of occult injury may be hemodynamically normal on arrival. Early identification of these patients may improve care, especially for those who require massive transfusion (MT). We hypothesized that elevated admission lactate would predict the need for MT in hemodynamically normal patients.
  
  
  
  All trauma patients treated at our university-based urban center over a 5-year period were reviewed. We included hemodynamically normal patients who had an admission lactate performed. First, a receiver-operating curve was used to determine the threshold lactate value. Subsequent analyses were then based on this value. Variables were analyzed using chi-square and unpaired t-tests, and univariable and multivariable regressions.
  
  
  
  There were 3468 hemodynamically normal patients with an admission lactate. Those who received MT (n = 19) had higher lactate than those who did not (n = 3449; 5.6 versus 2.6 mmol/L, P ≤ 0.001). Receiver-operating curve curve analysis revealed a threshold lactate value of 4 mmol/L with an area under the curve of 0.71. Patients with a lactate of >4 mmol/L had increased mortality (8% versus 2%), longer hospital length of stay (LOS, 6 versus 3 days), longer intensive care unit (ICU) LOS (6 versus 3 days), greater need for MT (2.8% versus 0.3%), and greater blood requirement (219 versus 38 mL; all P values < 0.001). After controlling for confounding variables, the predictive value of admission lactate >4 remained strong (odds ratio, 5.2; 95% confidence interval, 1.87-14.2).
  
  
  
  In hemodynamically normal trauma patients, the admission lactate of >4 mmol/L is a robust predictor of MT requirement and associated with poor outcomes.
authors.affiliation: Department of Surgery, University of California San Francisco East Bay, Oakland, California. Electronic address: m.brooke.sanchez@gmail.com.
authors.forename: Magdalene
authors.initials: M
authors.lastname: Brooke
authors.affiliation: Department of Surgery, University of California San Francisco East Bay, Oakland, California.
authors.forename: Louise
authors.initials: L
authors.lastname: Yeung
authors.affiliation: Department of Surgery, University of California San Francisco East Bay, Oakland, California.
authors.forename: Emily
authors.initials: E
authors.lastname: Miraflor
authors.affiliation: Department of Surgery, University of California San Francisco East Bay, Oakland, California.
authors.forename: Arturo
authors.initials: A
authors.lastname: Garcia
authors.affiliation: Department of Surgery, University of California San Francisco East Bay, Oakland, California.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Victorino
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D005260:Female; D006439:Hemodynamics; D006470:Hemorrhage / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D014947:Wounds and Injuries / Q000097:blood / Q000150:complications*
chemical_list: D015415:Biomarkers; D019344:Lactic Acid
keywords: Blood product; Hemodynamically normal; Lactate; Massive transfusion; Stable; Trauma