title: Evaluation of Serial Arterial Lactate Levels as a Predictor of Hospital and Long-Term Mortality in Patients After Cardiac Surgery.
abstract: OBJECTIVE
  Although hyperlactatemia is common after cardiac surgery, its value as a prognostic marker is unclear. The aim of the present study was to determine whether postoperative serial arterial lactate (AL) measurements after cardiac surgery could predict outcome.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Surgical intensive care unit in a tertiary-level university hospital.
  
  
  METHODS
  Participants included 2,935 consecutive patients.
  
  
  METHODS
  AL was measured on admission to the intensive care unit and 6, 12, and 24 hours after surgery, and evaluated together with clinical data and outcomes including in-hospital and long-term mortality.
  
  
  RESULTS
  In-hospital and long-term mortality (mean follow-up 6.3±1.7 years) were 5.9% and 8.7%, respectively. Compared with survivors, nonsurvivors showed higher mean AL values in all measurements (p<0.001). Hyperlactatemia (AL>3.0 mmol/L) was a predictor for in-hospital mortality (odds ratio = 1.468; 95% confidence interval = 1.239-1.739; p<0.001) and long-term mortality (hazard ratio = 1.511; 95% confidence interval = 1.251-1.825; p<0.001). Recent myocardial infarction and longer cardiopulmonary bypass time were predictors of hyperlactatemia. The pattern of AL dynamics was similar in both groups, but nonsurvivors showed higher AL values, as confirmed by repeated measures analysis of variance (p<0.001). The area under the curve also showed higher levels of AL in nonsurvivors (80.9±68.2 v 49.71±25.8 mmol/L/h; p = 0.038). Patients with hyperlactatemia were divided according to their timing of peak AL, with higher mortality and worse survival in patients in whom AL peaked at 24 hours compared with other groups (79.1% v 86.7%-89.2%; p = 0.03).
  
  
  CONCLUSIONS
  The dynamics of the postoperative AL curve in patients undergoing cardiac surgery suggests a similar mechanism of hyperlactatemia in survivors and nonsurvivors, albeit with a higher production or lower clearance of AL in nonsurvivors. The presence of a peak of hyperlactatemia at 24 hours is associated with higher in-hospital and long-term mortality.
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain. Electronic address: juancarloslopezde@hotmail.com.
authors: Juan C
authors: JC
authors: Lopez-Delgado
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Francisco
authors: F
authors: Esteve
authors: Physiological Sciences II Department, University of Barcelona, IDIBELL, Barcelona, Spain.
authors: Casimiro
authors: C
authors: Javierre
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Herminia
authors: H
authors: Torrado
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: David
authors: D
authors: Rodriguez-Castro
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Maria L
authors: ML
authors: Carrio
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Elisabet
authors: E
authors: Farrero
authors: Department of Public Health, University of Barcelona, Barcelona, Spain.
authors: Konstantina
authors: K
authors: Skaltsa
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Rafael
authors: R
authors: Mañez
authors: Intensive Care Department, Bellvitge University Hospital, IDIBELL (Institut d'Investigació Biomèdica Bellvitge), Barcelona, Spain.
authors: Josep L
authors: JL
authors: Ventura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000401:mortality* / Q000639:trends*; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers; D019344:Lactic Acid
keywords: area under the curve; cardiac surgery; hyperlactatemia; in-hospital; long-term mortality; postoperative care