Jaundice

Background

• Bilirubin is end product of heme metabolism
  • All bilirubin products in the body are initially unconjugated
  • Transported from albumin into hepatocytes; combine with glucuronic acid into conj bili
    • Excreted into biliary tract in conjugated form
• Only conjugated bilirubin is water-soluble (present in urine)
• Nl bilirubin level is <1.1, 70% unconjugated

Jaundice Types

• Prehepatic (overproduction)
  • Hemolysis
  • Primarily unconj bili
• Hepatic (inadequate processing)
  • Viral, alcohol, toxin
  • Primarily unconj bili
• Posthepatic (underexcretion)
  • Pancreatic tumor, choledocholithiasis
  • Primarily conj bili

Liver Function Tests

• Transaminases
  • Transaminitis in hundreds a/w mild injury; thousands suggests extensive injury
  • Elevations <5x normal typical of alcoholic liver disease
  • AST:ALT ratio > 2 common in alcoholic hepatitis (alcohol stimulates AST production)
  • May be normal in end-stage liver failure
  • ALT more specific marker of hepatocyte injury than AST
• Alk phos
  • Mild to moderate elevations accompany virtually all hepatobiliary disease
  • Elevations > 4x normal suggest cholestasis
• GGT
  • Elevation in setting of hepatitis suggestive of alcoholic etiology
• LDH
  • Moderate elevations are seen in all hepatocellular disorders and cirrhosis
  • Hemolysis results in elevation of LDH and unconj bili
• Ammonia
  • Elevation doesn't correlate w/ acute worsening of hepatic function in cirrhotic pt
  • Serve as marker of generalized decline than as diagnostic tool or therapeutic end point
• Coags
  • Marker of synthetic function
  • Correlation between PT prolongation and clinical outcome in fulminant liver disease
• Albumin
  • Marker of synthetic function
    • Half-life is 3wk so less useful than PT in evaluating fulminant liver disease
  • Low levels also seen in malnutrition

Differential Diagnosis

• Indirect >> direct: (Hematologic) [near nl AST/ALT/Alk P/PT/PTT]
  • Hemolytic
    • G6PD
    • Drug related
    • Autoimmune
  • Hematoma resorption
  • Infective erythropoiesis
  • Gilbert's
• Direct >> indirect: Increased Alk P (Obstructive) [nl to mild inc AST/ALT]
  • Choledocholithiasis
  • Cholecystitis
  • Ascending cholangitis
  • AIDS cholangiopathy
  • Stricture
  • Neoplasm
    • Panc head
    • Gallbladder
    • Primary liver
    • Metastatic
  • Obstructing AAA
• Nl Alk P (Hepatocellular/cholestatic) [greatly elevated AST/ALT]
  • Viral hepatitis
  • Fulminant hepatic failure
  • ETOH hepatitis
  • Ischemia
  • Toxins
    • isoniazide
    • phenytoin
    • acetaminophen
    • ritonavir
    • halothane
    • sulronamide
  • Autoimmune hepatitis
    • Primary biliary cirhosis
  • HELLP Syndrome
  • Congestive
    • CHF
    • Sepsis

Pregnancy Related

• HELLP Syndrome
• Acute fatty liver
• Hyperemesis gravidarum
• Cholestasis of pregnancy

Transplant Related

• Transplant rejection
• Graft-vs-host

Peds Related

• Inborn error of metabolism
• Physiologic neonatal

Additional Differential Diagnosis

• Reye's syndrome
• TPN
• Heatstroke
• Budd-Chiari (with acute ascites)
• Wilson's
• Sarcoidosis
• Amyloidosis

Masqueraders

• Carotenemia
• Quinacrine ingestion
• Dinitrophenol, teryl (explosive chemicals)

Only bilirubin stains the sclera

Diagnosis

Workup

• Urine pregnancy
• CBC
• Chemistry
• LFT
  • Hepatocyte injury: AST, ALT, alk phos
  • Hepatocyte catabolic activity: Bilirubin
• Coags
  • Hepatocyte synthetic function
• Albumin
  • Hepatocyte synthetic function
• Ammonia
  • Hepatocyte catabolic activity
• Acute hepatitis panel
• Lipase
• UA
• ?US vs. CT
• ?Retic count
• ?Haptoglobin/LDH
• ?APAP/ASA/Utox/ETOH

Disposition

New Onset Jaundice Admission Criteria

• Transaminase >1000IU/L
• Tbil >10mg/dL
• Evidence coagulopathy

See Also

• Neonatal Jaundice
• Acute Hepatitis
• Viral Hepatitis