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
Coagulation Markers (PT/PTT/INR)
- 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 Hyperbilirubinemia
- Hemolytic
- G6PD
- Drug related
- Autoimmune
- Hematoma resorption
- Infective erythropoiesis
- Gilbert's
Direct (Conjugated) Hyperbilirubinemia
- Choledocholithiasis
- Cholecystitis
- Ascending cholangitis
- AIDS cholangiopathy
- Stricture
- Neoplasm
- Pancreatic head
- Gallbladder
- Primary liver
- Metastatic
- Obstructing AAA
Hepatocellular damage
Patient will have severely elevated AST/ALT with often normal Alkaline Phosphatase
- Viral hepatitis
- Fulminant hepatic failure
- ETOH hepatitis
- Ischemia
- Toxins
- Isoniazide
- Phenytoin
- acetaminophen
- Ritonavir
- Halothane
- Sulronamide
- Autoimmune hepatitis
- Primary biliary cirhosis
- HELLP Syndrome
- Congestive Hepatopathy
Pregnancy Related
- HELLP Syndrome
- Acute fatty liver
- Hyperemesis gravidarum
- Cholestasis of pregnancy
Transplant Related
- Transplant rejection
- Graft-vs-host
Pediatric Related
- Inborn error of metabolism
- Neonatal jaundice (physiologic)
Additional Differential Diagnosis
- Reye's syndrome
- TPN
- Heatstroke
- Budd-Chiari (with acute ascites)
- Wilson's
- Sarcoidosis
- Amyloidosis
Masqueraders
Only bilirubin stains the sclera
- Carotenemia
- Quinacrine ingestion
- Dinitrophenol, teryl (explosive chemicals)
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