Splanchnic metabolism of fuel substrates in acute liver failure

Background/Aims: This study aimed to characterize the exchange of fuel substrates in the splanchnic circulation in acute liver failure. Methods: Liver vein catheterization was used in 22 patients with acute liver failure after development of hepatic encephalopathy grade III-IV. Healthy controls, patients with cirrhosis and patients with acute on chronic liver disease were also studied. Results: In acute liver failure there was splanchnic removal of glucose (0.21±0.44 mmol/min), release of lactate (0.34±0.37 mmol/min), pyruvate (0.08±0.06 mmol/min) and ketone bodies (0.04±0.02 mmol/min), while extraction of amino acids and free fatty acids was insignificant. In the acute liver failure group, a normal hepatic venous oxygen saturation (0.69±0.12) and normal pyruvate/lactate ratio suggested absence of hypoxia even though the acetoacetate/β-hydroxybutyrate ratio was decreased. Only in the acute liver failure group did the measured splanchnic oxygen content difference exceed what could be accounted for even by hypothesizing complete oxidation of all extracted blood-borne fuel substrates; oxidation of endogenous substrates may be quantitatively important in this condition. Conclusion: Acute liver failure was associated with a state of accelerated glycolysis in the splanchnic region, leading to release of lactate in the absence of splanchnic hypoxia.