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Flashcards in GI Deck (235)
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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

1

What are stellate cells?

Ito cells
Reside w/in Space of Disse
Store lipid and vitam A
Produce reticular fibers
Cirrhosis: multiply and produce large amounts of ECM

2

3 classifications of liver disease

1. Hepatocellular: acute, fulminant, chronic
2. Cholestatic: intrahepatic, extrahepatic
3. Cirrhosis

3

What viruses are associated with hepatocellular injury?

Hepatotropic: Hepatitis A,B,C,D,E

Systemic: EBV, CMV, HSV, enterovirus

4

What are microscopic features of acute hepatitis?

lobular disarray - disruption of architecture
ballooning degeneration
apoptotic bodies (Councilman bodies)
inflammatory infiltrates, activated Kupffer cells
regeneration (with resolution)

5

What is fulminant hepatitis?

Rare variant of acute hepatitis. Rapid onset of liver failure over period of days - weeks.
*Heralded by AMS and coagulopathy*

6

Causes of fulminant hepatitis

Drugs (acetaminophen overdose, antimycobacterial (rifampin, isoniazid), antidepressants (MAOi), halothane, mushroom poisoning)
Virus (HAV, HBV + HDV)
Autoimmune
Ischemia
Metabolic

7

What is chronic hepatitis?

Evidence of ongoing liver injury for >6mos
May be viral (HBV, HDV, HCV), autoimmune or metabolic

8

What is the predominant microscopic feature of chronic hepatitis?

inflammatory infiltrate surrounding portal tracts
fibrosis

9

What is "bridging" necrosis?

Seen in chronic hepatitis
fibrosis / necrosis stretching between portal tracts or from portal tract to central vein

10

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

11

What is choledocholithiasis?

gall stones w/in the common bile duct

12

What are the characteristic lab findings assoc. with cholestasis?

Elevated alkaline phosphatase
elevated gamma-glutamyl transferase (GGT)
elevated 5' nucleotidase

13

What hepatic condition presents with the highest aminotrasnferase elevations?

ALT/AST elevation hallmark of hepatocellular necrosis:
Acute Hepatitis 10-30x
Biliary obstruction 1-5x
Cirrhosis 1-3x
Hepatic metastases 1-2x

14

What defines acute liver failure?

Rapid onset of hepatic dysfunction with no underlying liver disease progressing to encephalopathy w/in 8-12 weeks

15

What are symptoms of acute liver failure?

Mental status changes
Jaundice, dark urine, light stool
Seizure
Hypoglycemia
Coagulopathy
Hepatorenal syndrome

16

How is cholestasis diagnosed?

Elevated alkaline phosphatase
Elevated GGT, 5' nucleosidase
Hypercholesterolemia
Hyperbilirubinemia (conjugated)
Prolonged prothrombin time (Vit K deficiency)
Anti-mitochondrial Ab (primary)

Imaging
Liver biopsy

17

What are the physical signs of portal hypertension?

1. Ascites
2. Splenomegaly
3. Abdominal vasculature accentuation

18

3 classifications of portal HTN

Pre hepatic
Intrahepetic
Post hepatic

19

What does TIPS stand for?

Transjugular Intrahepatic Portosystemic Shunt
Performed by interventional radiologist - treatment for portal HTN

20

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

21

What is therapy for chronic hepatic encephalitis?

Treat precipitating factor
Lactulose
Abx: Rifaximin, neomycin
Liver transplant

22

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

23

What are complications of ascites

Spontaneous Bacterial Peritonitis - esp. low protein fluid
Flood's syndrome: ruptured umbilical hernia
Plural effusion
Drug dilution in "3rd space"

24

What is hepatorenal syndrome?

Renal failure w/ accompanying advanced severe liver disease
No ATN (tubules intact - low urine Na+), but severe oliguria

25

How is hepatorenal syndrome diagnosed and treated?

Diagnosis: rule out pre-renal azotemia via trial of fluid expansion
Treatment: Often liver transplant. Dialysis.

26

Primary cause of unconjugated bilirubinemia

Hemolytic jaundice: production of bilirubin in excess of liver's ability to process it.

27

What are the 2 leading causes for liver transplant?

Hep C (45%)
Alcoholic cirrhosis (15%)

28

At what pressure within the hepatic portal vein is variceal bleeding likely?

>12mmHg

29

5 factors that contribute to chronic ascites

1. Portal HTN -> systemic vasodilation, decreased effective bv, SNS activation
2. RAAS activation -> increased Na+
3. ADH -> increased H2O
4. Increased transsinusoidal filtration
5. hypoalbuminemia -> decreased osm