title: Blood lactate level during extracorporeal life support as a surrogate marker for survival.
abstract: OBJECTIVE
  The establishment of reliable markers to monitor adequate tissue perfusion during extracorporeal life support is clinically important to improve outcomes.
  
  
  METHODS
  We evaluated 115 consecutive adult patients (aged 61.7 ± 13.4 years, 59 female patients) undergoing extracorporeal life support to manage low cardiac output syndrome after major cardiac surgery. The blood lactate levels serially measured during extracorporeal life support (at 6, 12, and 24 hours) were analyzed.
  
  
  RESULTS
  Forty-seven patients (40.8%) were weaned off extracorporeal life support successfully, and 32 patients (27.8%) survived to discharge. On logistic regression analysis, a high blood lactate level before extracorporeal life support (relative risk [RR], 1.19; 95% confidence interval [CI], 1.06-1.34) and cardiopulmonary bypass weaning failure after surgery (RR, 4.39; 95% CI, 1.44-13.35) emerged as baseline risk factors of mortality. After adjustment with these factors, blood lactate levels at 6 hours (RR, 1.24; 95% CI, 1.06-1.46), 12 hours (RR, 1.35; 95% CI, 1.10-1.67), and 24 hours (RR, 1.46; 95% CI, 1.10-1.93) were predictive of mortality. When the predictive values of serial blood lactate levels for mortality were assessed using the receiver operating characteristic method, the greatest accuracy was obtained at cutoff values of 7.05 mmol/L at 6 hours (sensitivity, 75.5%; specificity, 75.0%), 4.95 mmol/L at 12 hours (sensitivity, 70.4%; specificity, 76%), and 4.15 mmol/L at 24 hours (sensitivity, 62%; specificity, 93.1%).
  
  
  CONCLUSIONS
  Blood lactate measurement can be used as a reliable tool for monitoring adequate tissue perfusion during extracorporeal life support and was strongly predictive of mortality. Therefore, in patients without adequate decrement in lactate levels during extracorporeal life support, potential factors responsible for inadequate perfusion should be identified and corrected.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Sang-pil
authors.initials: SP
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Electronic address: jbkim1975@amc.seoul.kr.
authors.forename: Joon Bum
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Suk Jung
authors.initials: SJ
authors.lastname: Choo
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Cheol Hyun
authors.initials: CH
authors.lastname: Chung
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002303:Cardiac Output, Low / Q000097:blood / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D016009:Chi-Square Distribution; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects / Q000401:mortality; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010351:Patient Discharge; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D019344:Lactic Acid