Lactate dynamics in adult patients with cardiogenic shock supported with veno-arterial extracorporeal membrane oxygenation

Abstract Background Blood lactate is a point-of-care variable of inadequate tissue perfusion and has been linked to poor outcomes in patients with cardiogenic shock 1. Purpose We assessed the dynamic characteristics of lactate during VA-ECMO support to identify its predictive role in mortality. Methods A total of 195 adult patients who received VA-ECMO between 2016 and 2023, were retrospectively analyzed. Blood lactate was measured at ECMO initiation, after 12 h and 24 h. Lactate clearance (LC) was calculated at 12 h and 24 h 2,3. Results The median age of patients studied was 45(29,56) years, with a BMI of 25.5(22.3,31.5) kg/m2 and 58.5% of them were males without statistically significant differences between survivors and non-survivors. 152(77.9%) patients had cardiotomy, 22(11.28%) patients had ECPR, and 21(10.77%) patients had ECMO for non-cardiotomy cardiogenic shock. The non-survivors had more frequencies of chronic kidney disease (24.3% vs. 8.5%, p=0.01), atrial fibrillation (36.8% vs. 16.9%, p=0.006) and previous cardiotomies (50% vs. 32.2%, p=0.02) compared to the survivors respectively. Fifty-nine (30.3%) patients survived and were discharged while 101(51.8%) patients died on ECMO, and 35(17.9%) patients had ECMO weaning but did not survive to hospital discharge. The non-survivors had higher blood lactate levels at all measurement points with reduced LC at 12 h and 24 h. The cut-off lactate levels for differentiating mortality with VA-ECMO: the initial lactate 7.35mmol/L (AUR:0.756, 95%CI:0.682-0.83), lactate at 12 h 8.15mmol/L (AUR:0.88, 95%CI:0.83-0.93), lactate at 24 h 3.85 mmol/L (AUR:0.91, 95%CI:0.87-0.95), peak lactate 14.35 mmol/L(AUR:0.858,95% CI:0.80-0.91), LC at 12 h 21.94% (AUR:0.816, 95%CI:0.75-0.88) and LC at 24 h 40.3% (AUR:0.857, 95%CI: 0.80-0.91). Bivariate models using lactate levels and clearance at the same points revealed that blood lactate levels performed better than the clearance percentage. Conclusion Monitoring blood lactate dynamics is a valuable tool to predict mortality in adult patients with cardiogenic shock supported with VA-ECMO.ROC of blood lactate measurements. Lactate measurements and clearance.