Portal HTN

Question 1

How do patients with obstruction or biliary disease usually initially present as opposed to patients with parenchymal disease?

Answer 1

pruritis or jaundice

complication of portal HTN

Question 2

What pressures are considered abnormal and portal hypertension?

Answer 2

portal or splenic pressures >15 mm Hg or portal pressure >5 mm above IVC pressure

Question 3

How does blood exit the liver?

Answer 3

hepatic veins to IVC to right atrium

no valves - portal venous pressure approximates systemic venous pressure

Question 4

Where are the major components of resistance to portal blood flow that cause portal HTN?

Answer 4

pre-capillary or pre-sinusoidal

virtually no resistance through sinusoids

Question 5

What are the three main types of portal HTN?

Answer 5

post-hepatic (hepatic vein)
intra-hepatic - post-sinusoidal, sinusoidal, pre-sinusoidal
pre-hepatic (portal vein)

Question 6

What are causes of post-hepatic portal HTN?

Answer 6

heart failure
cor pulmonale
constrictive pericarditis

Question 7

What are intra-hepatic causes of portal HTN?

Answer 7

post-sinusoidal: veno-occlusive dz (thrombosis)
sinusoidal: alcoholic cirrhosis (pericellular fibrosis)
pre-sinusoidal: schisto (granulomas)

Question 8

What are pre-hepatic causes of portal HTN?

Answer 8

splenic vein thrombosis

portal vein thrombosis

Question 9

What are the complications of portal HTN?

Answer 9

variceal hemorrhage
ascites
hepatorenal syndrome
hepatic encephalopathy

Question 10

Which types of portal HTN have varices as a complication?

Answer 10

pre-hepatic or intra-hepatic

Question 11

What is the relative frequency of hemorrhage with different sites of collaterals?

Answer 11

gastro-esophageal: common
rectal: uncommon
Umbilical: not seen
retroperitoneal: very rare

Question 12

What findings can congestive splenomegaly be associated with?

Answer 12

thrombocytopenia
leukopenia
decreased RBC survival (splenic hemolysis)

Question 13

What are some signs and symptoms of someone with ruptured gastro-esophageal varices?

Answer 13

hematemesis
melena
orthostasis

Question 14

What is the threshold in most patients for variceal hemorrhage?

Answer 14

portal vein-IVC pressure gradient >12

Question 15

What can be done to treat variceal hemorrhage at the time of diagnosis?

Answer 15

band ligation during endoscopy

Question 16

How does sinusoidal portal HTN cause ascites?

Answer 16

leads to increased levels of extra-hepatic NO causing vasodilation including splanchnics –> increases portal blood flow further increasing portal pressures
vasodilation –> decreased EABV –> renal compensation –> increased hydrostatic pressure in splanchnic capillaries –> fluid flow to interstitial space

Question 17

What are the two major forces contributing to portal hypertensive ascites?

Answer 17

increased capillary hydrostatic pressure from systemic or portal venous HTN
decreased capillary oncotic pressure from hypoalbuminemia

Question 18

What are the two sources of ascitic fluid?

Answer 18

perisinusoidal fluid

transudation

Question 19

What is the non-portal way of getting ascites?

Answer 19

peritonitis - intra-abdominal inf or ascitic fluid from portal HTN getting inf

Question 20

What is spontaneous bacterial peritonitis (SBP) as opposed to secondary peritonitis?

Answer 20

secondary has source of direct spread like perf or abscess

Question 21

What types of patients more likely get SBP?

Answer 21

pts with low ascitic protein levels (total usually <2.5) - inadequate opsonization

Question 22

Which types of patients present with ascites and which don’t?

Answer 22

sinusoidal or post sinusoidal (inc post hepatic) obstruction of portal blood flow do
pre-sinusoidal rarely develop

Question 23

What circulatory changes are seen in a patient with ascites?

Answer 23

hyperdynamic systemic circulation - decreased peripheral vascular resistance, increased CO, diminished mean arterial pressure

Question 24

How do ascitic protein levels help determine cause of ascites?

Answer 24

post-sinusoidal (RHF) - high >2.5
secondary to cirrhosis - low 2.5
nephrosis - low <2.5

Question 25

How can the serum-ascites albumin gradient differentiate between etiologies of ascites?

Answer 25

portal HTN - >1.1 difference

other causes <= 1.1 difference

Question 26

What are portal hypertensive causes of ascites?

Answer 26

cirrhosis
hepatic vein thrombosis
restrictive pericarditis
RHF

Question 27

What are non-portal hypertensive causes of ascites?

Answer 27

peritoneal carcinomatosis
peritoneal tb
pancreatic duct extravasation
lymphatic obstruction

Question 28

What is the management of portal hypertensive ascites?

Answer 28

dietary sodium restriction (<4 g/d)
diuretic therapy (aldo antagonists - spironolactone)
possibly thiazide or furosemide

Question 29

What is the management of diuretic resistance ascites?

Answer 29

therapeutic paracentesis
TIPS
liver transplant

Question 30

What is the pathogenesis of hepatic encephalopathy due to portal HTN and shunting?

Answer 30

shunt causes decreased hepatic metabolism and clearance of ammonia
portal collaterals bypass liver completely

Question 31

What are precipitants of hepatic encephalopathy?

Answer 31

(GI) bleeding, inf, fluid or electrolyte abnormalities (excess dietary protein and hypokalemic alkalosis)
not seen first in those who’ve had therapeutic shunts created

Question 32

What is used that may be more effective than lactulose at treating encephalopathy?

Answer 32

non-absorbable antibiotics - can decrease bacteria that generate ammonia by urea metabolism