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 and Study Design:A prospective, observational study.Setting:A tertiary care center.Study Population:Two hundred children undergoing elective surgery for TOF.Study Method: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.Conclusion: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.

Clinical Utility of Delta Lactate for Predicting Early In-Hospital Mortality in Adult Patients: A Prospective, Multicentric, Cohort Study

“…Lactate clearance is a direct influence factor on survival, more significant than the initial or maximum lactate level reached, in critically ill patients [ 32 , 33 ]. Ladha et al studied patients admitted to the ICU with a lactate clearance ≥ 10% with respect to the initial value after 6 h, all of whom required less ventilatory support, less need for vasopressor therapy and had a shorter hospital stay [ 34 ]. More recent studies showed a higher probability of survival when a second lactate level concentration was less than 3.7 mmol/L, or with a relative lactate clearance ≥ 8% [ 35 ].…”

Short-term prognostic value of perioperative coronary sinus-derived-serum cardiac troponin-I, creatine kinase-MB, lactate, pyruvate, and lactate-pyruvate ratio in adult patients undergoing open heart surgery

“…Lactate was the second best diagnostic discriminator of myocardial injury with an optimal “cutoff” value of >2 mmol/L at immediately after aortic declamping (AUC, 0.89 [±SE 0.04, 95% CI: 0.80–0.96]; sensitivity 83.33%; specificity 80%; likelihood ratio (+) 4.16) [ Figure 8 ]. [ 29 30 31 ] cTn-I was the third best diagnostic discriminator of myocardial injury with an optimal “cutoff” value of > 2.1 ng/mL at immediately after aortic declamping (AUC, 0.88 [±SE 0.04, 95% CI: 0.80–0.95]; sensitivity 81.25%; specificity 80%; likelihood ratio (+) 4.06) [ Figure 8 ]. CK-MB was the fourth best diagnostic discriminator of myocardial injury with an optimal “cutoff” value of > 58 log units/mL after coming off bypass before decannulation (AUC, 0.85 [±SE 0.05, 95% CI: 0.78–0.94]; sensitivity 77.08%; specificity 80%; likelihood ratio (+) 3.85) [ Table 4 and Figure 8 ].…”

The Effect of Serum Lactate and Lactate Clearence on Mortality in Cardiac Surgery Patients

“…Blood lactate level is a dynamic variable and the mechanism of increased lactate level may be caused by many different etiologies. 6 Therefore, the measurement of a single lactate level may not always give sufficient information about the patient. In order to improve the results when treating patients, it is necessary to distinguish the relatively benign and transient causes of lactate elevation from tissue hypoxia.…”

“…Similarly, in another study evaluating children who were operated for tetralogy of fallot, it was stated that postoperative early lactate clearance can be used to predict hospital mortality and in patients with lactate clearance higher than 10% in the first 6 hours; less ventilation time, less inotropic requirement, and less ICU stay durations were detected. 6 In a recent meta-analysis, it was found that lactate clearance predicts mortality reliably. 22 Finally, Lopez et al also demonstrated that low lactate clearance (<3 mmol/L) is the best predictor of morbidity and mortality in patients with heart failure.…”

“…frequently used to guide interventions such as fluid administration or inotropic therapy, and decreased lactate clearance is associated with prolonged mechanical ventilation and prolonged intensive care unit (ICU) stay. [4][5][6] The blood lactate level is a dynamic variable, so a single lactate measurement may not always give sufficient information about the patient. Recent studies have shown that single measurement of lactate level has limited clinical benefit for outcome estimation.…”