title: The role of blood lactate clearance as a predictor of mortality in children undergoing surgery for tetralogy of Fallot.
abstract: BACKGROUND
  The identification of biomarkers for predicting morbidity and mortality, particularly in pediatric population undergoing cardiac surgery will contribute toward improving the patient outcome. There is an increasing body of literature establishing the clinical utility of hyperlactatemia and lactate clearance as prognostic indicator in adult cardiac surgical patients. However, the relationship between lactate clearance and mortality risk in the pediatric population remains to be established.
  
  
  OBJECTIVE
  To assess the role of lactate clearance in determining the outcome in children undergoing corrective surgery for tetralogy of Fallot (TOF).
  
  
  METHODS
  A prospective, observational study.
  
  
  METHODS
  A tertiary care center.
  
  
  METHODS
  Two hundred children undergoing elective surgery for TOF.
  
  
  METHODS
  Blood lactate levels were obtained as baseline before operation (T0), postoperatively at admission to the cardiac intensive care unit after surgery (T1), and then at every 6 h for the first 24 h of Intensive Care Unit (ICU) stay (T6, T12, T18, and T24, respectively). The lactate clearance in the study is defined by the equation ([lactate initial - lactate delayed]/lactate initial) ×100%. Lactate clearance was determined at T1-T6, T1-T12, T1-T18, and T1-T24 time interval, respectively. The primary outcome measured was mortality. Secondary outcomes measured were the duration of mechanical ventilation, duration of inotropic requirement, and duration of ICU stay.
  
  
  RESULTS
  Eleven out of the two hundred patients enrolled in the study died. Nonsurvivors had higher postoperative lactate concentration (P < 0.05) and low-blood lactate clearance rate during 24 h (P < 0.05) in comparison to the survivors. Lactate clearance was significantly higher in survivors than in nonsurvivors for the T1-T6 period (19.55 ± 14.28 vs. 5.24 ± 27.79%, P = 0.009) and remained significantly higher for each studied interval in first 24 h. Multivariate logistic regression analysis of statistically significant univariate variables showed early lactate clearance to have a significant relationship with mortality. Patients with a lactate clearance >10%, relative to patients with a lactate clearance <10%, in the early postoperative period, had improved outcome and lower mortality.
  
  
  CONCLUSIONS
  Lactate clearance in the early postoperative period (6 h) is associated with decreased mortality rate. Patients with higher lactate clearance (>10%) after 6 h have improved outcome compared with those with lower lactate clearance.
authors.forename: Suruchi
authors.initials: S
authors.lastname: Ladha
authors.affiliation: Department of Cardiac Anesthesia, C. N. Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Poonam Malhotra
authors.initials: PM
authors.lastname: Kapoor
authors.forename: Sarvesh Pal
authors.initials: SP
authors.lastname: Singh
authors.forename: Usha
authors.initials: U
authors.lastname: Kiran
authors.forename: Ujjwal Kumar
authors.initials: UK
authors.lastname: Chowdhury
mesh_terms: D000465:Algorithms; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002675:Child, Preschool; D003422:Critical Care; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012121:Respiration, Artificial; D013771:Tetralogy of Fallot / Q000097:blood / Q000401:mortality* / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D002316:Cardiotonic Agents; D019344:Lactic Acid