title: Outcome with high blood lactate levels during cardiopulmonary bypass in adult cardiac operation.
abstract: BACKGROUND
  High blood lactate levels during cardiopulmonary bypass (CPB) are associated with tissue hypoperfusion and may contribute to postoperative complications or death. The objective of this study was to determine an association between blood lactate levels during CPB and perioperative morbidity and mortality.
  
  
  METHODS
  We reviewed 1,376 patients who underwent cardiac operation with CPB. Patients with abnormal preoperative blood lactate levels were excluded (n = 101). Blood lactate concentration during CPB, clinical data, and perioperative events were recorded.
  
  
  RESULTS
  Peak blood lactate levels of 4.0 mmol/L or higher during CPB were present in 227 patients (18.0%). Postoperative mortality was higher in this group than in the patients who had peak blood lactate levels of less than 4.0 mmol/L during CPB (11.0% versus 1.4%; p < 0.001, relative risk [RR] = 9.0). Postoperative hemodynamic instability occurred in 29.5% of patients with elevated levels of lactate during CPB compared with 10.9% of patients with lower lactate levels (p < 0.001, RR = 3.4). Overall, major postoperative complications occurred in 43.2% and 21.8% of patients in each group, respectively (p < 0.001, RR = 2.7). Logistic regression analysis revealed that peak blood lactate levels of 4.0 mmol/L or higher during CPB were strongly associated with postoperative mortality (p = 0.0001) and morbidity (p = 0.013).
  
  
  CONCLUSIONS
  Blood lactate concentration of 4.0 mmol/L or higher during CPB identifies a subgroup of patients with increased risk of postoperative morbidity and mortality.
authors.affiliation: Department of Surgery, Montreal Heart Institute, Quebec, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Demers
authors.forename: S
authors.initials: S
authors.lastname: Elkouri
authors.forename: R
authors.initials: R
authors.lastname: Martineau
authors.forename: A
authors.initials: A
authors.lastname: Couturier
authors.forename: R
authors.initials: R
authors.lastname: Cartier
mesh_terms: D000328:Adult; D000368:Aged; D002315:Cardiopulmonary Bypass; D002423:Cause of Death; D001026:Coronary Artery Bypass; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D012086:Reoperation; D015996:Survival Rate
chemical_list: D019344:Lactic Acid