Impaired Liver Function

Impaired Liver Function

1. Hepatocellular Injury

   • Injury to hepatocytes
     • Some causes: viral hepatitis, alcohol/drug toxicity, NAFLD, haemochromatosis

2. Cholestasis

   • Decreased bile flow
     • Some causes: obstruction by gall stones & malignancies, drugs, biliary cirrhosis

3. Liver Failure

   • Massive liver destruction
     • Fulminant/ chronic cirrhosis

4. Bilirubin Metabolism

   • Normal: Liver conjugates and excretes bilirubin
     • Abnormal: Jaundice (icterus) - bilirubin accumulates in tissues e.g. skin/sclera
       • Pre-hepatic - increased haemolysis and unconjugated bilirubin levels
       • Intrahepatic - liver damage reduces bilirubin conjugation and/or secretion
       • Post-hepatic - obstruction of bile flow after liver/cholestasis (e.g. gallstones)
     • Abnormal: Kernicterus - unconjugated bilirubin crosses BBB in premature babies
     • Abnormal: Steatorrhoea (pale fatty stools) - unable to produce/secrete bile needed for fat digestion

5. Alcohol & Drug Metabolism

   • Normal: detoxification of drugs & alcohol
     • Abnormal: Inadequate detox - leads to cell toxicity

6. Cholesterol & Steroid Metabolism

   • Normal: synthesis of lipoproteins, metabolism of steroids
     • Abnormal: inadequate metabolism leads to low serum cholesterol
     • Abnormal: increased steroid hormone levels
       • High sex hormones
         • Gynecomastia in males
       • High aldosterone
         • Fluid retention, edema

7. Carbohydrate Metabolism

   • Normal: glycogenesis (absorptive state); glycogenolysis & gluconeogenesis (post-absorptive state)
     • Abnormal: risk of hypoglycemia

8. Storage of Vitamins & Minerals

   • Normal: Stores Vit A, B12, D, E & K, Fe, Cu
     • Abnormal: impaired absorption of fat-soluble vitamins, high free iron (cell toxicity)

9. Protein Metabolism

   • Normal: synthesise albumin
     • Abnormal: low plasma albumin
       • Ascites
   • Normal: synthesise clotting factors
     • Abnormal: low clotting factors
       • Bleeding tendency
   • Normal: form urea from protein deamination
     • Abnormal: elevated ammonia levels
       • Cell toxicity

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