Liver

  • Role of the Liver

    • Glycogenolysis: Conversion of stored glycogen back to glucose, released into the bloodstream for use by the body.

    • Gluconeogenesis: Production of new glucose from amino acids and fatty acids within the liver.

  • Impact of Liver Dysfunction

    • If liver function is impaired, less effective glucose conversion/storage occurs leading to hyperglycemia, characterized by:

      • Elevated blood sugars post-meals (postprandial).

      • Extended duration of high blood sugars.

    • Failure to clear ammonia can cause neurological changes due to increased ammonia levels in the blood.

  • Protein Metabolism

    • The liver synthesizes almost all plasma proteins, including:

      • Albumin: Maintains osmotic pressure; its reduction results in swelling and ascites.

      • Blood clotting factors (e.g., prothrombin) requiring Vitamin K.

  • Fat and Vitamin Metabolism

    • Storage: Liver stores fat, vitamins (A, B12, D, several B complexes), iron, and copper.

    • Bile: Crucial for fat emulsification and absorption; bile salts are recycled back to the liver for bilirubin excretion.

      • Types of Bilirubin:

        • Conjugated (direct): Cleared from circulation, can be excreted.

        • Unconjugated (indirect): Bound to proteins, not excreted.

  • Consequences of Liver Functioning Issues

    • Impaired bilirubin conjugation can lead to elevations in unconjugated bilirubin and a decrease in conjugated bilirubin, causing:

      • Stool discoloration: Clay-colored stools due to lack of bilirubin.

      • Urine discoloration: Dark orange urine.

      • Jaundice: Yellowing of skin and sclera due to bilirubin accumulation.

      • Pruritus (itching): Due to bile salts accumulating in the skin.

  • Gastrointestinal Symptoms

    • Malay occur particularly in the absence of bile salts leading to:

      • Dyspepsia: Indigestion.

      • Anorexia: Loss of appetite.

      • Nausea/Vomiting: Gastrointestinal complaints.

      • Steatorrhea: Fatty stools due to unabsorbed fats.

  • Liver Function Tests

    • Indicators of liver function:

      • Abnormal liver function tests emerge only after more than 70% liver damage.

      • Elevated total bilirubin indicates liver cell injury (normal is around 1.2 mg/dL).

      • Prothrombin time: May remain abnormal after vitamin K administration if liver damage is severe.

      • Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST): Elevated levels indicate liver inflammation or disease.

      • Alkaline phosphate: Indicative of biliary obstruction.

  • Imaging and Diagnosis

    • Ultrasound and CT scans: Useful for identifying liver size and structural abnormalities.

    • Liver Biopsies: May be performed to diagnose masses and evaluate liver health.

      • Coagulation studies should precede biopsies due to clotting risks in liver-compromised patients.

  • Jaundice and Related Symptoms

    • Symptoms of jaundice develop once bilirubin levels reach 2 mg/dL or higher.

    • Insensitive skin in darker-pigmented individuals may delay recognition of jaundice.

    • Patients with liver dysfunction may also experience severe itching due to bile salts.

  • Portal Hypertension

    • Elevated blood pressure in the hepatic circulation due to liver obstruction, leading to:

      • Esophageal varices: Risk of rupture and bleeding.

      • GI bleeding: Presence of blood in vomit or stool (hematemesis/melena).

      • Treatment focuses on preventing bleeding.

  • Ascites

    • Resulting from decreased albumin production leading to fluid leakage into the peritoneal cavity.

    • Managed by:

      • Measuring abdominal girth and weights.

      • Positioning in Fowler's to facilitate lung expansion.

      • Diuretics and therapeutic paracentesis as needed for excess fluid removal.

  • Hepatic Encephalopathy

    • Signs include personality changes, intellectual impairment, and decreased consciousness.

    • Treatment aims to control ammonia levels; lactulose is commonly used.

    • Symptoms may start with slight confusion and progress to more severe disorientation and coma.

  • Types of Hepatitis

    • Acute Liver Inflammation: Caused by viral infections, drugs, alcohol, or autoimmune diseases.

      • Hepatitis A: Fecal-oral; typically resolves spontaneously. Vaccination reduces incidence.

      • Hepatitis B: Blood/body fluid transmission; can lead to chronic complications. Vaccinations are effective.

      • Hepatitis C: Blood transmission; often chronic.

      • Hepatitis D: Requires Hepatitis B to replicate.

      • Hepatitis E: Rare and fecal-oral, primarily through contaminated water.

  • Toxic Hepatitis

    • Caused by exposure to certain chemicals and can lead to acute liver failure.

    • Management: Removal of the offending substances; potential need for a liver transplant.

  • Cirrhosis

    • Progressive liver disease characterized by scar tissue formation and liver dysfunction.

    • Causes include chronic Hepatitis C, alcohol abuse, and non-alcoholic fatty liver disease.

    • Management focuses on slowing progression and treating complications; specific types include:

      • Alcoholic cirrhosis: Liver injury due to alcohol.

      • Biliary cirrhosis: Chronic inflammation and obstruction of bile ducts.