Point of care serum lactate levels as a prognostic marker of outcome in complex pediatric cardiac surgery patients: Can we utilize it?

BACKGROUND: Post-operative course after complex pediatric cardiac surgery is unpredictable. Although, change in arterial lactate levels has been used as a surrogate marker for many years, scientific evidence correlating the early perioperative lactate levels with outcome is still lacking. OBJECTIVE: To evaluate the trends in lactate levels from intraoperative period to an extended post-operative period in pediatric intensive care unit (PICU) and to assess its usefulness as a prognostic marker. DESIGN: Prospective observational study. SETTING: Tertiary pediatric cardiac surgical unit. PATIENTS: Thirty-five non-consecutive children aged 1-140 months who underwent surgery for congenital heart diseases (CHD) on cardiopulmonary bypass (CPB). INTERVENTION: None. MATERIALS AND METHODS: Arterial blood lactate levels were obtained at the following time points: After induction of anesthesia, 15 and 45 min after institution of CPB, at the start of rewarming, after sternotomy closure, then at 1, 6, 24, and 48 h in PICU. Other hemodynamic and clinical variables, CPB variables, blood gas values, and laboratory variables were also recorded. RESULTS: Four patients died out of 35 patients (11.4%). Non-survivors showed significant persistent elevation in lactates (>4.0 mmol/l). Peak lactates correlate significantly with longer aortic cross clamp time, CPB duration, ventilation hours and PICU stay. CONCLUSION: Early point of care lactate can be a useful prognostic marker in post-cardiac surgery patients in adjunct with other parameters measured in PICU. This reiterates the importance of measuring lactates and timely recognition of at-risk patients, which on early intervention can help in reducing post-operative morbidity and mortality.