Biomarkers of multiorgan dysfunction in ECMO are important indicators of patient prognosis. Consistently high lactate levels and poor ECMO clearance signal poor perfusion and unnecessary care – lactate levels above 8 mmol/L at 12 hours, persistence above 2.5 mmol/L at 24 hours, or clearance below 22% are strong signs of high risk of death. Total bilirubin is a better marker of liver function than enzymes, with levels above 15 mg/dL quadrupling the risk of death. Acute kidney injury requiring renal replacement therapy is associated with a 60–80% mortality rate. Systemic coagulopathy with a DIC score ≥ 5 or a decrease in platelet count ≥ 50% on the first day increases the risk of death 8- to 9-fold. High levels of interleukin-6 and procalcitonin (≥0.5 μg/L) correlate with refractory shock and significantly worse outcomes. Persistence of these abnormalities indicates irreversible organ damage and a poor prognosis.