Comparison of the predictive ability of lactate and central venous blood gas in pediatric venoarterial mode extracorporeal membrane oxygenation outcome

Background: This study aims to compare lactate and central venous blood gas in the prediction of outcome in pediatric venoarterial mode extracorporeal membrane oxygenation (V-A ECMO). Method: This was a retrospective observational study conducted on patients undergoing V-A ECMO care in the pediatric intensive care unit of a tertiary medical center in Taiwan. Patients under 18 years of age undergoing V-A ECMO from January 2009 to April 2019 were included in this study. Results: This study consisted of 47 children who received V-A ECMO with an overall weaning rate of 66.0%. The mean age was 5.5 years and mean ECMO duration was 11.6 days. Successful weaning group had significantly lower lactate levels at initial (58.7 ± 47.0 mg/dL vs. 108.0 ± 55.3 mg/dL, p = 0.003), 0–12 h (37.8 ± 29.0 mg/dL vs. 83.5 ± 60.0 mg/dL, p Z 0.001), and 12–24 h (29.4 ± 26.9 mg/dL vs. 69.1 ± 59.1 mg/dL, p = 0.003) after ECMO initiation; however, the central venous blood gas including pH, HCO₃, CO₂, base excess (BE), and O₂ saturation showed no significant difference. The favorable outcome group had significantly lower lactate levels at 0–12 h (32.8 ± 26.3 mg/dL vs. 71.3 ± 53.3 mg/dL, p = 0.005), and 12–24 h (20.7 ± 10.2 mg/dL vs. 61.9 ± 53.5 mg/dL, p = 0.002); however, the HCO₃ levels (26.2 ± 4.5 mmol/L vs. 22.9 ± 6.8 mmol/L, p = 0.042) and BE (2.2 ± 5.4 vs. 2.2 ± 8.5, p = 0.047) were significantly higher at 12–24 h. In multivariate logistic regression, 12–24 h lactate value was an independent factor for unfavorable outcomes (p = 0.015, odds ratio [OR] = 1.1) with the best cut-off value of 48.6 mg/dL (sensitivity 48%, specificity 100%). Conclusion: Lactate has better outcome prediction than central venous blood gas in pediatric V-A ECMO. The lactate value 12–24 h after ECMO initiation was an independent factor for unfavorable outcomes.