Flashcards in GI Deck (235)
What activities are carried out in Zone 1 vs Zone 3 of hepatic lopules?
Zone 1: adjacent to triad, O2 rich. gluconeogenesis, B-oxidation, AA metabolism, formation of urea
Zone 3: adjacent to central vein, O2 poor. P450 reactions, lipid synthesis, glycolysis
What are stellate cells?
Reside w/in Space of Disse
Store lipid and vitam A
Produce reticular fibers
Cirrhosis: multiply and produce large amounts of ECM
3 classifications of liver disease
1. Hepatocellular: acute, fulminant, chronic
2. Cholestatic: intrahepatic, extrahepatic
What viruses are associated with hepatocellular injury?
Hepatotropic: Hepatitis A,B,C,D,E
Systemic: EBV, CMV, HSV, enterovirus
What are microscopic features of acute hepatitis?
lobular disarray - disruption of architecture
apoptotic bodies (Councilman bodies)
inflammatory infiltrates, activated Kupffer cells
regeneration (with resolution)
What is fulminant hepatitis?
Rare variant of acute hepatitis. Rapid onset of liver failure over period of days - weeks.
*Heralded by AMS and coagulopathy*
Causes of fulminant hepatitis
Drugs (acetaminophen overdose, antimycobacterial (rifampin, isoniazid), antidepressants (MAOi), halothane, mushroom poisoning)
Virus (HAV, HBV + HDV)
What is chronic hepatitis?
Evidence of ongoing liver injury for >6mos
May be viral (HBV, HDV, HCV), autoimmune or metabolic
What is the predominant microscopic feature of chronic hepatitis?
inflammatory infiltrate surrounding portal tracts
What is "bridging" necrosis?
Seen in chronic hepatitis
fibrosis / necrosis stretching between portal tracts or from portal tract to central vein
What are microscopic indicators of HBV, HCV, and autoimmune hepatitis?
HBV: ground-glass cytoplasm
HCV: microvessicular fatty change and portal tract lymphoid aggregates
autoimmune: plasma cell infiltrates of portal triad
What is choledocholithiasis?
gall stones w/in the common bile duct
What are the characteristic lab findings assoc. with cholestasis?
Elevated alkaline phosphatase
elevated gamma-glutamyl transferase (GGT)
elevated 5' nucleotidase
What hepatic condition presents with the highest aminotrasnferase elevations?
ALT/AST elevation hallmark of hepatocellular necrosis:
Acute Hepatitis 10-30x
Biliary obstruction 1-5x
Hepatic metastases 1-2x
What defines acute liver failure?
Rapid onset of hepatic dysfunction with no underlying liver disease progressing to encephalopathy w/in 8-12 weeks
What are symptoms of acute liver failure?
Mental status changes
Jaundice, dark urine, light stool
How is cholestasis diagnosed?
Elevated alkaline phosphatase
Elevated GGT, 5' nucleosidase
Prolonged prothrombin time (Vit K deficiency)
Anti-mitochondrial Ab (primary)
What are the physical signs of portal hypertension?
3. Abdominal vasculature accentuation
3 classifications of portal HTN
What does TIPS stand for?
Transjugular Intrahepatic Portosystemic Shunt
Performed by interventional radiologist - treatment for portal HTN
How do acute and chronic hepatic encephalopathy differ?
Acute: Type A: assoc. w/ acute disease. Delirium and convulsions progressing to coma. BBB and cerebral edema are common.
Chronic: Types B and C: chronic disease: pathogenesis unclear. Asterixis, Hyperreflexia, Mental disturbances, EEG changes
Production of toxic substances by gut bacteria implicated
What is therapy for chronic hepatic encephalitis?
Treat precipitating factor
Abx: Rifaximin, neomycin
What does protein content of ascites fluid indicate?
Etiology of ascites
Serum albumin - ascites albumin
if > 1.1, portal HTN likely
Elevated ascites albumin: tumor or chronic infection
What are complications of ascites
Spontaneous Bacterial Peritonitis - esp. low protein fluid
Flood's syndrome: ruptured umbilical hernia
Drug dilution in "3rd space"
What is hepatorenal syndrome?
Renal failure w/ accompanying advanced severe liver disease
No ATN (tubules intact - low urine Na+), but severe oliguria
How is hepatorenal syndrome diagnosed and treated?
Diagnosis: rule out pre-renal azotemia via trial of fluid expansion
Treatment: Often liver transplant. Dialysis.
Primary cause of unconjugated bilirubinemia
Hemolytic jaundice: production of bilirubin in excess of liver's ability to process it.
What are the 2 leading causes for liver transplant?
Hep C (45%)
Alcoholic cirrhosis (15%)
At what pressure within the hepatic portal vein is variceal bleeding likely?