Liver disease Flashcards
What are the three stages of alcoholic liver disease?
Fatty changes (steatosis), alcoholic hepatitis and chronic cirrhosis.
What is alcoholic hepatitis?
Inflammatory liver injury caused by chronic heavy intake of alcohol.
What is the aetiology of alcoholic hepatitis? (x3)
- Fatty liver infiltration occurs from build-up of NADH caused by reduction of alcohol, by alcohol dehydrogenase and acetaldehyde dehydrogenase, by inhibiting gluconeogenesis and increasing fatty acid oxidation.
- Alcohol is also metabolised by cytochrome P450 which produces free radicals and damages tissue
- Chronic alcohol exposure also activates hepatic macrophages which produce TNF-a leading to inflammation
What is the pathophysiology of alcoholic hepatitis? (x6)
Liver histopathology shows:
- Centrilobular ballooning degeneration and necrosis of hepatocytes
- Steatosis (abnormal fat retention)
- Neutrophilic inflammation
- Cholestasis (flow of bile reduced or blocked)
- Mallory hyaline inclusions (eosinophilic intracytoplasmic aggregates of cytokeratin intermediate filaments)
- Giant mitochondria
What are the risk factors of alcoholic hepatitis? (x6)
Alcohol, hepatitis C, female (develops more rapidly and in lower drinking levels), overweight, smoking, Hispanic.
What is the epidemiology of alcoholic hepatitis: Percentage of heavy drinkers?
10-35% of heavy drinkers.
What are the symptoms of alcoholic hepatitis? (x4 and x5)
- May remain asymptomatic
- Symptoms can range from: nausea, malaise, epigastric/right hypochondrial pain, low-grade fever to…
- Jaundice, abdominal discomfort, distension, swollen ankles, GI bleeding (haematemesis or meleana)
How do patients often present with alcoholic hepatitis?
Asymptomatic and with a trigger event e.g., aspiration pneumonia or injury.
How may a woman present differently with alcoholic hepatitis?
More florid (red, flushed complexion) illness than a man.
What are the signs of alcoholic EXCESS? (x10)
Malnourished, palmar erythema, Dupuytren’s contracture, facial telangiectasia, parotid enlargement, spider naevi, gynaecomastia, testicular atrophy, hepatomegaly, easy bruising.
What are the signs of severe alcoholic hepatitis? (x8)
- Febrile
- Tachycardia
- Jaundice
- Bruising
- Encephalopathy. Clinical features of this include hepatic foeter, liver flap (asterixis), drowsiness, unable to copy a five-pointed star, disorientated.
- Ascites
- Hepatomegaly
- Splenomegaly
What is hepatic foeter?
Condition seen in portal hypertension where portosystemic shunting allows thiols to pass directly into the lungs, producing a sweet faecal odour.
What is hepatic encephalopathy?
Altered level of consciousness as a result of liver dysfunction or portosystemic shunting.
What are the blood investigations for alcoholic hepatitis? (x4)
- FBC would show low Hb, high MCV, high WCC, low platelets
- LFTs: high transaminases (ALT, AST), AST:ALT ratio more than 2 (reversal of ratio = viral or non-alcoholic fatty liver disease), high bilirubin (reflects cholestasis and impaired metabolic function of liver), low albumin (impaired liver function), high AlkPhos (reflects cholestasis), high gamma-GT
- U&E: urea and potassium low, unless significant renal impairment. Elevated urea in the presence of normal creatinine suggest active GI bleed.
- Clotting: prolonged PT is a sensitive marker of significant liver damage
What are the other investigations for alcoholic hepatitis? (x4)
- USS: to exclude other causes of liver impairment such as malignancy
- Upper GI endoscopy: investigate for varices
- Liver biopsy: percutaneous or trans-jugular to differentiate from other causes of hepatitis
- Electroencephalogram: for slow-wave activity indicative of encephalopathy
How is alcoholic hepatitis managed acutely? (x7)
- Thiamine, vitamin C and other multivitamins (initially parenterally)
- Monitor and correct K+, Mg2+ and glucose abnormalities
- Ensure adequate urine output
- Treat encephalopathy with oral lactulose and phosphate enemas
- Ascites managed by diuretics or therapeutic paracentesis
- Glypressin and N-acetylcysteine for hepatorenal syndrome
- Alcohol withdrawal – look at separate notes
How is alcoholic hepatitis managed with nutrition? (x2)
Increased calorie intake. Protein restriction should be avoided unless patient is encephalopathic. Nutritional supplementation and vitamins should be started parenterally initially and continued orally after.
Why is protein restriction indicated in encephalopathy?
Ammonia is a key factor in the disease pathogenesis. Ammonia is produced in the metabolism of proteins.
!!! What is the pathogenesis of hepatic encephalopathy? (x2)
- FAILURE TO METABOLISE NITROGEN-CONTAINING COMPOUNDS: As the liver fails, nitrogenous waste (as ammonia) builds up in the circulation and passes to the brain, where astrocytes clear it (by processes involving the conversion of glutamate to glutamine). This excess glutamine causes an osmotic imbalance and a shift of fluid into these cells—hence cerebral oedema.
- PORTOSYSTEMIC SHUNTING: In portal hypertension, some of the portal circulation is shunted into the systemic circulation. As such, nitrogenous waste in the portal system escapes into the systemic system and can access the brain.
How is alcoholic hepatitis medically managed?
Steroid therapy
What are the complications of alcoholic hepatitis? (x3)
Acute liver decompensation, hepatorenal syndrome (renal failure secondary to advanced liver disease) and cirrhosis.
What is the prognosis of alcoholic hepatitis?
Mortality in first month = 10%. 40% in first year. If alcohol intake continues, progression to cirrhosis within 1-3 years.
What are two prognostic scores in alcoholic hepatitis?
(1) Maddrey’s discriminant function = (bilirubin/17) + (prolongation of PT x 4.6). If MDF is higher than 32, this indicates over 50% 30-day mortality. (2) Glasgow alcoholic hepatitis score = allocates a score based on age, WCC, urea, PT ratio and bilirubin. If GCS higher than or equal to 9, there is an over 50% 30-day mortality risk.
What is cirrhosis?
End-stage of chronic liver damage with replacement of normal liver architecture with diffuse fibrosis and nodules of regenerating hepatocytes.
What is a decompensated liver?
Decompensated alcohol related liver disease occurs when there is a deterioration in liver function in a patient with cirrhosis which presents with jaundice, coagulopathy, ascites, GI bleeding and hepatic encephalopathy.
What are the causes of cirrhosis? (x9)
- Alcohol
- Chronic viral hepatitis
- Autoimmune hepatitis
- Drugs such as methotrexate and hepatotoxic drugs
- Inherited: alpha1-antitrypsin deficiency, haemochromatosis, Wilson’s disease, galactosaemia, CF
- Vascular: Budd-Chiari syndrome or hepatic venous congestion
- Chronic biliary diseases: PSC
- Cryptogenic (unknown origin): 5-10%
- Non-alcoholic steatohepatitis (NASH): associated with OBESITY (obesity is one of the main causes of cirrhosis in the Western world), diabetes, total parenteral nutrition, short bowel syndromes, hyperlipidaemia and drugs
What are the factors that can precipitate liver decompensation? (x9)
Infection, GI bleeding, constipation, high-protein meal, electrolyte imbalances, alcohol, drugs, tumour development, portal vein thrombosis.
What is the epidemiology of cirrhosis: Incidence mortality?
Top 10 leading causes of death in the world.
What are the symptoms of cirrhosis? (x5, x3, x4, x4)
- EARLY: anorexia, nausea, fatigue, weakness, weight loss
- REDUCED LIVER SYNTHETIC FUNCTION: easy bruising, abdominal swelling, ankle oedema
- REDUCED DETOXIFICATION FUNCTION: jaundice, personality change, altered sleep pattern, amenorrhoea
- PORTAL HYPERTENSION: abdominal swelling, haematemesis, PR bleeding or melaena
What are the signs of cirrhosis? (x5 +11)
- ABCDE
- Asterixis
- Bruises
- Clubbing
- Dupuytren’s contracture
- Erythema (palmar)
- Jaundice, gynaecomastia, leukonychia (hypoalbuminemia), parotid enlargement (alcoholic), spider naevi, excoriations, ascites, hepatomegaly (shrunken in later stage), testicular atrophy, caput medusa, splenomegaly.
!!! Hepatic failure, cirrhosis and symptoms?
Hepatic failure in cirrhosis leads to coagulopathy, encephalopathy, hypoalbuminemia (oedema), sepsis, spontaneous bacterial peritonitis and hypoglycaemia.
!!! Portal hypertension, cirrhosis and symptoms?
Portal hypertension in cirrhosis leads to ascites, splenomegaly, portosystemic shunt and caput medusa.
What are the blood investigations for cirrhosis? (x9)
- FBC would show low Hb, high MCV, high WCC, low platelets (hypersplenism)
- LFTs: high transaminases (ALT, AST), high bilirubin (reflects cholestasis and impaired metabolic function of liver), low albumin (impaired liver function), high AlkPhos (reflects cholestasis), high gamma-GT
- Clotting: prolonged PT is a sensitive marker of significant liver damage
- Serum AFP (alpha-fetoprotein): increased but can also suggest carcinoma.
- U&E: low sodium associated with ascites.
- Serology: viral serology of HBsAg (Hep B surface antigen), HBsAb (Hep B), HCV ab (Hep C), antinuclear antibodies (autoimmune hepatitis), antimitochondrial antibodies (primary biliary cholangitis), anti-smooth muscle antibodies (autoimmune hepatitis)
- Iron studies: serum ferritin, iron, total iron binding capacity (hemochromatosis)
- Alpha1-antitrypsin: hepatic inflammation
- Caeruloplasmin: low in Wilson’s disease
What are other investigations for cirrhosis? (x4)
- Ascitic tap: microscopy, culture and sensitivity, biochemistry (protein, albumin, amylase) and cytology. If neutrophils are over 250/mm^3, this indicates spontaneous bacterial peritonitis.
- Liver biopsy: percutaneous or transjugular if clotting deranged or ascites present.
- Imaging: USS, CT or MRI to detect complications such as ascites, carcinoma or hepatic/portal vein thrombosis, to exclude biliary obstruction
- Endoscopy: examine for varices, portal hypertensive gastropathy
What is assessed in a liver biopsy for cirrhosis? (x3) Grade and stage?
Histopathology: periportal fibrosis, loss of normal liver architecture and nodular appearance. Grade refers to the assessment of degree of inflammation, whereas stage refers to the degree of architectural distortion, ranging from mild portal fibrosis to cirrhosis
What is Child-Pugh grading in cirrhosis?
Class A is score 5-6, Class B is score 7-9 and Class C is score 10-15.
How is cirrhosis managed? (x3)
- Treat the cause
- Nutrition
- Treat the complications
How are the complications of cirrhosis treated? (x3)
- Encephalopathy: treat infections, lactulose, phosphate enemas and avoid sedation
- Ascites: diuretics, dietary sodium restriction, therapeutic paracentesis, fluid restriction in patients with hyponatraemia. Monitor daily weight and aim for 0.5kg loss per day.
- SBP: antibiotics
How is cirrhosis surgically managed? (x2) But?
Consider insertion of TIPS (Transjugular intrahepatic portosystemic shunt) to relieve portal hypertension although it may precipitate encephalopathy. Only curative measure = transplant.
What are the complications of cirrhosis? (x5)
Portal hypertension with ascites, encephalopathy or variceal haemorrhage, SBP, hepatocellular carcinoma, renal failure (hepatorenal syndrome), pulmonary hypertension (hepatopulmonary syndrome)
How does cirrhosis lead to renal failure?
Reduced hepatic clearance of immune complexes leads to trapping in kidneys.
What is the prognosis of cirrhosis: 5-year survival? Ascites 2-year survival?
Poor: 5-year survival is 50%. In the presence of ascites, 2-year survival is 50%.
What is the difference between cirrhosis and fibrosis?
Fibrosis leads to cirrhosis.
What is liver failure?
Aka ACUTE LIVER FAILURE. Severe liver dysfunction defined by jaundice, encephalopathy and coagulopathy.
What are the classifications of liver failure? (x4)
- Defined as presentation of encephalopathy relative to jaundice
- Hyperacute: jaundice with encephalopathy occurring in LESS THAN 7 DAYS
- Acute: jaundice with encephalopathy occurring from 1 to 4 WEEKS OF ONSET
- Subacute: jaundice with encephalopathy occurring 4 to 12 WEEKS OF ONSET
- Acute-on-chronic: acute deterioration (decompensation) in patients with chronic liver disease (cirrhosis)
What are the causes of liver failure? (x10)
- VIRAL: Hepatitis A, B, D, E, ‘non-A-E hepatitis’, yellow fever
- DRUGS: paracetamol overdose, idiosyncratic drug reactions (such as anti-TB therapy)
- AUTOIMMUNE: autoimmune hepatitis
- Budd-Chiari syndrome: hepatic vein thrombosis
- Pregnancy
- Malignancy e.g., lymphoma
- Haemochromatosis
- Mushroom poisoning (Amanita phalloides)
- Wilson’s Disease
- PSC or PBC
What is the pathogenesis of liver failure? (x3)
- Jaundice from decreased secretion of conjugated bilirubin
- Encephalopathy from increased delivery of gut-derived products into the systemic circulation and brain, arising from decreased extraction of nitrogenous products by liver and portal systemic shunting. Ammonia may play a role hence management includes protein-restriction.
- Coagulopathy: decreased synthesis of clotting factors. Decreased synthesis of platelets from hypersplenism if chronic portal hypertension. Platelet functional abnormalities associated with jaundice or renal failure.
What is the histopathological pathophysiology of liver failure?
Most cases are characterised by massive hepatocyte necrosis and apoptosis may coexist.
What is the pathophysiology of liver failure in paracetamol overdose?
Paracetamol is predominantly metabolised in the liver through glucuronidation and sulfation, with a small amount metabolised by the cytochrome P450 system. A toxic intermediate, NAPQI, generated via the P450 pathway is subsequently conjugated by glutathione. In the setting of paracetamol overdose, glutathione stores may become depleted, resulting in direct hepatocyte injury via NAPQI.
What are the risk factors for liver failure? (x6)
Alcohol, barbiturates, poor nutritional status, age over 40 years, female gender, pregnancy.
How do alcohol, barbiturates and nutritional deficiency contribute to liver failure?
Induction of the P450 system through chronic alcohol use or barbiturates and depletion of glutathione stores in settings such as nutritional deficiency may result in a greater propensity to develop paracetamol hepatotoxicity.