The clinical significance of blood lactate levels in evaluation of adult patients with veno-arterial extracorporeal membrane oxygenation

BACKGROUND: Veno-arterial ECMO is a life-supporting procedure that can be done to the patients with cardiogenic shock which is associated with hyperlactatemia. The objective of this study was to detect the validity of serial measurements of arterial lactate level in differentiating hospital mortality and neurological outcome after VA-ECMO support for adult patients with cardiogenic shock. All consecutive patients ≥ 18 years admitted with cardiogenic shock and supported with VA-ECMO between 2015 and 2019 in our tertiary care hospital were retrospectively studied. RESULTS: The study included 106 patients with a mean age of 40.2 ± 14.4 years, a mean BMI of 26.5 ± 7 and mostly males (69.8%). The in-hospital mortality occurred in 56.6% and acute cerebral strokes occurred in 25.5% of the enrolled patients. The non-survivors and the patients with acute cerebral strokes had significantly higher arterial lactate levels at pre-ECMO initiation, post-ECMO peak and after 24 h of ECMO support compared to the survivors and those without strokes, respectively. The peak arterial lactate ≥ 14.65 mmol/L measured after ECMO support had 81.7% sensitivity and 89.1% specificity for predicting hospital mortality [AUROC 0.889, p < 0.001], while the arterial lactate level ≥ 3.25 mmol/L after 24 h of ECMO support had 88.3% sensitivity and 97.8% specificity for predicting hospital mortality [AUROC 0.93, p < 0.001]. The peak lactate ≥ 15.15 mmol/L measured after ECMO support had 70.8% sensitivity and 69% specificity for predicting cerebral strokes [AUROC 0.717, p < 0.001], while the lactate level ≥ 3.25 mmol/L after 24 h of ECMO support had 79.2% sensitivity and 72.4% specificity for predicting cerebral strokes [AUROC 0.779, p < 0.001]. Progressive hyperlactatemia (OR = 1.427, 95% CI 1.048–1.944, p = 0.024) and increasing SOFA score after 48 h (OR = 1.819, 95% CI 1.374–2.409, p < 0.001) were significantly associated with in-hospital mortality after VA-ECMO support. Post hoc analysis detected a significantly high frequency of hypoalbuminemia in the non-survivors and in the patients who developed acute cerebral strokes during VA-ECMO support. CONCLUSION: Progressive hyperlactatemia after VA-ECMO initiation for adult patients with cardiogenic shock is a sensitive and specific predictor of hospital mortality and acute cerebrovascular strokes. According to our results, we could recommend early VA-ECMO initiation to achieve adequate circulatory support and better outcome.