Portal HTN and Ascites Flashcards Preview

Gastrointestinal > Portal HTN and Ascites > Flashcards

Flashcards in Portal HTN and Ascites Deck (21):
1

Two blood supplies to the liver are?

Hepatic artery (30%)
Portal vein (70%)

2

Influence of Cirrhosis on blood flow thorugh the liver?

Cirrhosis causes fibrosis with distortion of the vasculature. Sinusoids turn into capillaries. You get increased blood flow to the stomach and intestines

3

During portal hypertension, venous collaterals form from teh distal esophagus to where

The rectum

4

Anterior collaterals form via which vein?

umbillical

5

Posterior collaterals form via what veins?

Retroperitoneal, you get splenorenal shunts.

6

What is a varice?

Varices are tortuous venous collaterals under high pressure

7

treatment of variceal bleeds

- Volume replacement
- Correct the coagulopathy
- Vasoconstriction of the splanchnic vessels
- decrease blood flow to the stomach and intestines as much as possible
- decrease blood flow via the collaterals

8

What is the classic triad of bad variceal bleeds

1) High Pressure Bleeding
2) Thrombocytopenia- low plateletts
3) Coagulopathy- synthetic impairment of clotting factors

9

Mechanism of ascites

- Increased resistance to portal venous flow
- Increased flow to the portal vein because of the increased flow to stomach and intestine from the arterial side due to vasodilators being where they shouldnt
- Increased lymphatic flow
- LEAKAGE of lymphatic flow from the liver and intestines into peritoneal space (liters of fluid)
- Increased portosystemic shunting of vasodilators leads to increased systemic vasodilation

10

Systemic vasodilation leads to

low blood pressure....kidneys are not perfused

11

When the kidneys are not perfused how do they react?

Increased vasoconstriction in the kidneys
Increased Renin- ANgiotensin- Aldosterone leading to sodium reabsorption and water holding

12

The pattern, starting with ascites is

Ascites forms when you get too much blood backed up in the portal vein and lymph system and fluid begins to leak out into the peritoneum---> Shunting of blood away from the portal system brings vasodilators out into systemic circulation where they are not supposed to be --> You get total body hypoperfusion---> Kidneys react by increasing fluid retention through RAAS---> this worsens ascites and leads to edema

13

Ascites has what effect on kidney function

Decreased renal clearance
Increased sodium retention
Decreased creatinine clearance

14

Know...Ascites can cause so much pressure in the peritoneum that you have difficulty breathing and eating due to pressure on the stomach and diaphragm

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15

Fluid can get out of the abdomen, past the diaphragm, and into pleural space which can give you

hepatic hydrothorax

16

Bacterial peritonitis

Any fluid that is undrained can get infected.
Gram negative can get into the peritoneal fluid and cause massive infection. This is an emergency

17

Treatment of ascites

- sodium restriction
- Diuretics
- Treat the liver disease
- Large volume paracentesis

18

So, Chronic portal hypertension causes an increased transvascular pressure gradient between the portal system and the systemic circulation (b/w the portal vein and the hepatic vein). This blood has to get back to the heart though so it will take the path of least resistance,,, portosystemic shunting occurs. As this occurs, vasodilators that our body generally doesn't see because they are confined to the splanchnic circulation, enter the systemic circulation. This leads to increased blood flow to the splanchnic system arteries yet still tons of resistance on the venous side.

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19

Remember, what causes the portal hypertension?

The Cirrhosis of the liver

20

Beta Blockers?

Decrease the risk of variceal bleed by lowering the bloodflow to the splanchnics

21

Child Pugh Classification looks at what?

APE BA

Albumin, Prothrombin Time, Encephalopathy, Bilirubin, Ascites

Child A- Decent function (5-6)
Child B- Not so decent (7-9)
Child C- Dismal (10-15)