Red Flags in Normothermic Machine Perfusion

Trenches in Transplant Surgery · Aug 25, 2025 · 25m

During normothermic machine perfusion (NMP), several red flags may prompt declining a liver for transplantation. The most critical biochemical warning is failure to clear lactate to <2–2.5 mmol/L within 2–3 hours, or a rebound rise after initial clearance, indicating poor hepatocellular metabolism. Persistent metabolic acidosis despite heavy bicarbonate support and sharply rising ALT/AST (especially ALT >6000 IU/L) reflect ongoing hepatocellular injury. Perfusion parameters such as low hepatic artery (<150 mL/min) or portal flow (<500 mL/min) at target pressures, or rising vascular…