Liver Cirrhosis: A High-Yield USMLE Review

Cirrhosis is the end-stage of chronic liver injury, characterized by diffuse fibrosis and regenerative nodules that distort hepatic architecture. It results from a wide range of chronic insults—chronic viral hepatitis (HBV, HCV), alcoholic liver disease, and NASH among them—and predisposes to a cascade of life-threatening complications including portal hypertension, ascites, hepatic encephalopathy, and hepatocellular carcinoma. It is a heavily tested topic because its complications require specific, high-yield management.

Presentation

• Abdominal distension from ascites, with shifting dullness and a fluid wave on exam, often accompanied by peripheral edema
• Variceal bleeding presenting as massive hematemesis, melena, and hemodynamic instability
• Hepatic encephalopathy—confusion, disorientation, and asterixis, frequently precipitated by constipation or other triggers
• Hepatic decompensation or RUQ mass may signal underlying hepatocellular carcinoma
• May be complicated by spontaneous bacterial peritonitis presenting with fever, confusion, or worsening clinical status in a patient with ascites

Diagnosis

• Paracentesis with fluid analysis and SAAG: a serum-ascites albumin gradient ≥1.1 g/dL confirms portal hypertension as the cause of ascites; ascitic fluid PMN count ≥250 cells/mm³ indicates spontaneous bacterial peritonitis
• Upper endoscopy: screen all cirrhotics for esophageal varices
• Hepatic encephalopathy is a CLINICAL diagnosis—serum ammonia may be elevated but does NOT correlate reliably with severity or clinical stage and should not be used to grade or guide management (it can even be normal in encephalopathic patients)
• HCC surveillance with ultrasound ± AFP every 6 months in at-risk cirrhotics
• Liver test interpretation aids etiology: hepatocellular pattern shows AST/ALT >> ALP, while an AST:ALT ratio >2:1 suggests alcoholic liver disease

Management

• Variceal bleeding: resuscitate with restrictive transfusion (target Hgb 7–8 g/dL), give octreotide for splanchnic vasoconstriction, start prophylactic antibiotics (improves survival), and perform urgent endoscopy with band ligation; TIPS for refractory bleeding
• Primary prophylaxis of varices: non-selective beta-blockers (propranolol, nadolol) or endoscopic band ligation for medium/large varices
• Ascites: sodium restriction, diuretics (spironolactone plus furosemide), large-volume paracentesis with albumin if >5 L removed, and TIPS for refractory ascites
• Spontaneous bacterial peritonitis: empiric ceftriaxone or cefotaxime plus IV albumin, with long-term prophylaxis (norfloxacin or TMP-SMX) after recovery
• Hepatic encephalopathy: identify and correct the precipitant, and treat with lactulose and rifaximin—titrate therapy to clinical response, not to ammonia levels
• Liver transplant is the definitive treatment for end-stage disease

High-yield

• Cirrhosis of ANY etiology is the biggest risk factor for hepatocellular carcinoma—surveille with ultrasound ± AFP every 6 months
• SAAG ≥1.1 g/dL = portal hypertension; ascitic PMN ≥250/mm³ = spontaneous bacterial peritonitis
• Hepatic encephalopathy is a clinical diagnosis—serum ammonia levels do NOT correlate with severity and should not be used to grade or follow the disease
• Over-transfusion in variceal bleeding is harmful—target Hgb 7–8 g/dL because raising volume increases portal pressure and worsens bleeding
• Prophylactic antibiotics after variceal bleeding improve survival, not just prevent infection
• Constipation precipitates encephalopathy by giving gut bacteria more time to generate ammonia
• AST:ALT ratio >2:1 points to alcoholic liver disease; abstinence improves survival even at the cirrhotic stage
• Both PBC and PSC can progress to cirrhosis; PSC (male, UC-associated, beading on MRCP) carries cholangiocarcinoma risk

Pitfalls

• Using serum ammonia levels to diagnose, grade, or monitor hepatic encephalopathy—it correlates poorly with clinical status; diagnosis and titration of therapy are clinical
• Transfusing to "normalize" hemoglobin in variceal bleeding—this raises portal pressure and increases mortality; use a restrictive 7–8 g/dL target
• Forgetting empiric antibiotics in variceal bleeding, which are proven to improve survival
• Missing spontaneous bacterial peritonitis—any cirrhotic with ascites plus fever, confusion, or worsening status warrants diagnostic paracentesis
• Overlooking a treatable precipitant (e.g., constipation) when managing hepatic encephalopathy rather than just treating the confusion
• Failing to maintain HCC surveillance in cirrhotics regardless of the underlying etiology