Liver, Biliary & Pancreatic Disorders: NAFLD/MASLD, Cirrhosis & Cholecystitis
Key Takeaways
- Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD, formerly NAFLD) is characterized by hepatic steatosis linked with metabolic risk factors; ALT is typically higher than AST (AST/ALT ratio < 1) in uncomplicated disease.
- Non-invasive risk stratification for liver fibrosis in MASLD utilizes the FIB-4 index (age, AST, ALT, platelets); a score < 1.30 has a high negative predictive value for advanced fibrosis.
- Serum-Ascites Albumin Gradient (SAAG) >= 1.1 g/dL confirms portal hypertension as the etiology of ascites; Spontaneous Bacterial Peritonitis (SBP) is diagnosed by an ascitic absolute neutrophil count (ANC) >= 250 cells/mm³.
- Acute cholecystitis presents with steady RUQ pain, fever, leukocytosis, and a positive Murphy's sign; ultrasound findings include gallbladder wall thickening (>3-4 mm), pericholecystic fluid, and sonographic Murphy sign.
- Acute pancreatitis diagnosis requires at least 2 of 3 criteria: classic severe epigastric pain radiating to the back, serum lipase or amylase >= 3 times upper limit of normal, and characteristic cross-sectional imaging.
Liver, Biliary & Pancreatic Disorders: NAFLD/MASLD, Cirrhosis & Cholecystitis
Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD / NAFLD)
Under AASLD consensus guidelines, Nonalcoholic Fatty Liver Disease (NAFLD) is termed Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD). MASLD defines hepatic steatosis occurring with at least one cardiometabolic risk factor (central obesity, type 2 diabetes, hypertension, hypertriglyceridemia, low HDL) without heavy alcohol intake (<20 g/day women, <30 g/day men). Insulin resistance drives increased hepatic de novo lipogenesis and impaired fatty acid beta-oxidation.
- MASH (Metabolic Dysfunction-Associated Steatohepatitis): The progressive inflammatory subtype characterized by hepatic steatosis, lobular inflammation, and hepatocellular ballooning degeneration. MASH drives progressive liver fibrosis, cirrhosis, and Hepatocellular Carcinoma (HCC).
Diagnostics & FIB-4 Risk Stratification
Patients are usually asymptomatic, presenting with incidental aminotransferase elevations (ALT > AST, AST/ALT ratio < 1 in early disease, distinguishing it from alcoholic liver disease where AST/ALT > 2). Abdominal ultrasound shows increased hepatic echogenicity ("bright liver").
Fibrosis risk stratification in primary care:
- FIB-4 Index (incorporating Age, AST, ALT, and Platelet Count):
- FIB-4 < 1.30 (<2.0 in age >=65): Low risk for advanced fibrosis; managed in primary care with lifestyle modification.
- FIB-4 1.30 to 2.67: Indeterminate risk; secondary testing with Transient Elastography (FibroScan) required.
- FIB-4 > 2.67: High risk for advanced fibrosis; urgent Hepatology referral.
- Liver Biopsy: Definitive gold standard to stage fibrosis.
Management Protocols
- Weight Loss: 7% to 10% total body weight loss resolves MASH and regresses fibrosis.
- Pharmacotherapy: GLP-1 receptor agonists (semaglutide, tirzepatide) improve glycemic control, promote weight loss, reduce steatosis, and prevent fibrosis progression; Resmetirom (selective thyroid hormone receptor-beta agonist dosing 80 mg or 100 mg daily based on body weight) for non-cirrhotic MASH with moderate-to-advanced fibrosis (stages F2-F3).
- Statin Safety: Statins are safe and explicitly indicated in MASLD/MASH to lower cardiovascular disease mortality, the leading cause of death in this population.
Cirrhosis & Complications of End-Stage Liver Disease
Cirrhosis is irreversible end-stage liver disease characterized by diffuse hepatic fibrosis, disruption of lobular architecture, and regenerative nodules.
Physical Exam Stigmata & Major Complications
Physical stigmata include spider angiomas, palmar erythema, gynecomastia, caput medusae, Dupuytren contracture, jaundice, scleral icterus, splenomegaly, and asterixis (flapping tremor).
1. Portal Hypertension & Esophageal Varices
Elevated portal vascular resistance causes collateral venous dilation.
- Screening EGD required for all cirrhotic patients.
- Primary prophylaxis for medium/large varices: Non-selective beta-blockers (nadolol, propranolol, carvedilol) or endoscopic variceal band ligation (EVL).
2. Ascites & Spontaneous Bacterial Peritonitis (SBP)
- SAAG Calculation: $\text{Serum Albumin} - \text{Ascitic Albumin}$.
- SAAG >= 1.1 g/dL: Confirms Portal Hypertension (cirrhosis, heart failure).
- SAAG < 1.1 g/dL: Non-portal hypertension etiologies (peritoneal carcinomatosis, tuberculosis).
- Ascites Management: Sodium restriction (<2000 mg/day) + oral diuretics: Spironolactone and Furosemide at a 100 mg : 40 mg ratio (up to max 400 mg : 160 mg daily).
- Spontaneous Bacterial Peritonitis (SBP): Bacterial translocation from gut lumen into ascites without intra-abdominal surgical infection.
- Diagnostic Benchmark: Ascitic fluid Absolute Neutrophil Count (ANC) >= 250 cells/mm³ (WBC x % neutrophils).
- Treatment: IV 3rd gen cephalosporin (cefotaxime or ceftriaxone) + IV Albumin (1.5 g/kg day 1, 1 g/kg day 3).
- Prophylaxis: Long-term oral fluoroquinolone (ciprofloxacin) or TMP-SMX.
3. Hepatic Encephalopathy
Driven by systemic ammonia accumulation, precipitated by infection, constipation, hyponatremia, or GI bleeding.
- First-Line: Lactulose titrated to 2 to 3 soft bowel movements daily (converts $NH_3$ to non-absorbable $NH_4^+$).
- Add-on Therapy: Oral Rifaximin (550 mg BID).
4. HCC Surveillance
Abdominal ultrasound +/- serum alpha-fetoprotein (AFP) every 6 months.
Viral Hepatitis Overview & Screening
- Hepatitis B: Screen with HBsAg, Anti-HBs, Anti-HBc. Universal screening recommended for all adults at least once per lifetime.
- Hepatitis C: USPSTF mandates universal one-time screening for all adults aged 18 to 79 (HCV antibody with reflex RNA PCR). Curable with oral direct-acting antiviral (DAA) therapy for 8-12 weeks.
Biliary & Pancreatic Disorders
- Biliary Colic: Episodic postprandial RUQ pain lasting <6 hours due to transient cystic duct obstruction; normal labs.
- Acute Cholecystitis: Prolonged cystic duct obstruction causing constant RUQ pain (>6 hours), fever, leukocytosis, and Murphy's Sign (inspiratory arrest during subcostal palpation).
- Ultrasound Findings: Gallbladder wall thickening (>3-4 mm), pericholecystic fluid, gallstones, and sonographic Murphy sign. A HIDA scan (hepatobiliary iminodiacetic acid scan demonstrating non-visualization of the gallbladder) is indicated if ultrasound is equivocal.
- Treatment: NPO, IV isotonic fluids, IV broad-spectrum antibiotics, and early laparoscopic cholecystectomy (within 24-72 hours of admission).
- Choledocholithiasis & Cholangitis: Common bile duct stone causing jaundice and elevated direct bilirubin/alk phos. Ascending cholangitis presents with Charcot's Triad (RUQ pain, fever, jaundice) or Reynolds' Pentad (+ hypotension/altered mental status), requiring emergency ERCP for biliary decompression.
- Acute Pancreatitis: Caused by gallstones (40%) or alcohol (30%), followed by hypertriglyceridemia (>1000 mg/dL). Severe epigastric pain radiating to back, relieved leaning forward. Exam may show Cullen's or Grey Turner's sign in hemorrhagic cases.
- Atlanta Diagnostic Criteria (requires >= 2 of 3): 1) Classic epigastric pain, 2) Serum Lipase >= 3 times upper limit of normal, 3) Characteristic CT/MRI imaging.
- Management: Aggressive IV hydration with Lactated Ringer's solution (200-500 mL/hr), early oral refeeding as tolerated. Clinical severity is evaluated using Ranson criteria or BISAP score.
A 50-year-old male presents with severe, constant epigastric pain that radiates directly through to his back, accompanied by persistent vomiting. On examination, he is leaning forward on the exam table for pain relief. Laboratory testing reveals serum lipase 1,150 U/L (normal reference 10-140 U/L). According to the Atlanta criteria, which statement regarding his diagnosis and initial management is correct?
A 46-year-old female presents to the emergency department reporting acute, constant right upper quadrant abdominal pain that began 8 hours ago after eating a cheeseburger. She has low-grade fever (100.9°F) and nausea. On physical exam, the nurse practitioner notes sharp inspiratory arrest when deeply palpating the right subcostal area. Which diagnostic imaging finding on right upper quadrant ultrasound would most specifically confirm acute cholecystitis?
A 58-year-old male with long-standing metabolic syndrome and type 2 diabetes presents for routine follow-up. Laboratory evaluation shows AST 52 U/L, ALT 78 U/L, and Platelets 110,000/mcL. Calculate his FIB-4 index (Age 58, AST 52, ALT 78, Platelets 110). Based on the FIB-4 score (>2.67), which management step is indicated?
A 54-year-old female with alcohol-induced cirrhosis is admitted with increasing abdominal distension and fever (101.2°F). A diagnostic paracentesis yields cloudy ascitic fluid. Lab analysis shows total protein 1.1 g/dL, serum albumin 3.2 g/dL, ascitic albumin 1.8 g/dL, and ascitic total WBC 1,200/mm³ with 75% neutrophils. What is the calculated SAAG and the definitive diagnosis?