title: Prognostic significance of blood lactate and lactate clearance in trauma patients.
abstract: BACKGROUND
  Lactate has been shown to be a prognostic biomarker in trauma. Although lactate clearance has already been proposed as an intermediate endpoint in randomized trials, its precise role in trauma patients remains to be determined.
  
  
  METHODS
  Blood lactate levels and lactate clearance (LC) were calculated at admission and 2 and 4 h later in trauma patients. The association of initial blood lactate level and lactate clearance with mortality was tested using receiver-operating characteristics curve, logistic regression using triage scores, Trauma Related Injury Severity Score as a reference standard, and reclassification method.
  
  
  RESULTS
  The authors evaluated 586 trauma patients (mean age 38±16 yr, 84% blunt and 16% penetrating, mortality 13%). Blood lactate levels at admission were elevated in 327 (56%) patients. The lactate clearance should be calculated within the first 2 h after admission as LC0-2 h was correlated with LC0-4 h (R=0.55, P<0.001) but not with LC2-4 h (R=0.04, not significant). The lactate clearance provides additional predictive information to initial blood lactate levels and triage scores and the reference score. This additional information may be summarized using a categorical approach (i.e., less than or equal to -20 %/h) in contrast to initial blood lactate. The results were comparable in patients with high (5 mM/l or more) initial blood lactate.
  
  
  CONCLUSIONS
  Early (0-2 h) lactate clearance is an important and independent prognostic variable that should probably be incorporated in future decision schemes for the resuscitation of trauma patients.
authors.affiliation: Department of Anesthesiology and Critical Care, Centre Hospitalo-Universitaire (CHU) Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Department of Anesthesiology and Critical Care, Université Pierre et Marie-Curie-Paris 6, Paris, France.
authors.forename: Marie-Alix
authors.initials: MA
authors.lastname: Régnier
authors.forename: Mathieu
authors.initials: M
authors.lastname: Raux
authors.forename: Yannick
authors.initials: Y
authors.lastname: Le Manach
authors.forename: Yves
authors.initials: Y
authors.lastname: Asencio
authors.forename: Johann
authors.initials: J
authors.lastname: Gaillard
authors.forename: Catherine
authors.initials: C
authors.lastname: Devilliers
authors.forename: Olivier
authors.initials: O
authors.lastname: Langeron
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D019344:Lactic Acid / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D008657:Metabolic Clearance Rate / Q000502:physiology; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D014947:Wounds and Injuries / Q000097:blood* / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019344:Lactic Acid