Liver

Question 1

Kidney is to nephron as liver is to

Answer 1

Lobule (acinus)

Question 2

How much lymph is made in the liver and where is it made?

Answer 2

About 50% of the body’s lymph is made there by hepatocytes, and drain into the space of Disse before emptying into the lymphatic duct

Question 3

Hemoglobin to Bilirubin metabolism

Answer 3

• Old RBCs are cleared by the spleen
• In the spleen = Hgb -> Heme -> Bilirubin (Unconjugated)
• Unconjugated bilirubin is lipophilic and neurotoxic. Travels bound to albumin to liver.
• Liver conjugates it with glucuronic acid to increase it’s water solubility
• This is now CONJUGATED bilirubin and is excreted in the bile

Question 4

PT and liver function

Answer 4

Good for detecting ACUTE liver injury.

This is because factors V and VII have short 1/2 lives (

Question 5

Albumin and liver function

Answer 5

Not very specific for liver disease because many things can cause albumin levels to decrease
- Not good indicator of acute liver disease (1/2 life of albumin is 21 days)

Question 6

AST/ALT ratio > ___ suggests cirrhosis or alcoholic liver disease

Answer 6

2

Question 7

This is the MOST sensitive lab indicator of biliary tract obstruction

Answer 7

5-NT

5-NT > GGTP > AP

Question 8

In hepatocellular injury, will you see a rise in conjugated or unconjugated bilirubin

Answer 8

Conjugated

Question 9

This clotting factor is made by the liver but NOT by hepatocytes

Answer 9

Factor VIII

It’s made by sinusoidal cells

Question 10

How liver handles Tylenol

Answer 10

• Tylenol produces a toxic metabolite called NAPQI
• This is normally conjugated with glutathione so be excreted in the bile
• In this case, all the glutathione gets used up and NAPQI starts harming the liver

Question 11

Risk factors for halothane hepatitis

Answer 11

Fat females > 40 with multiple exposures.

• Genetics
• CYP2E1 induction (from alcohol, ionized, and phenobarbital)

Question 12

How does alcohol affect the liver

Answer 12

Impairs fatty acid metabolism, head to fat buildup within the liver –> hepatomegaly

Question 13

Why is propranolol good in liver failure?

Answer 13

It’s a NONSELECTIVE BB
- B1 = decreased CO
- B2 = splanchnic vasoconstrition
Remember that splanchnic vasoconstriction will reduce portal venous pressures and treat esophageal varies

Question 14

How does amiodarone affect the liver?

Answer 14

It’s hepatotoxic

Question 15

Main 2 considerations for patients with liver injury presenting for surgery

Answer 15

1) Maintain hepatic BF

2) Avoid any drugs that are hepatotoxic or suppress the CYP450

Question 16

Anesthesia considerations for pt with acute hepatitis

Answer 16

1) Maintain hepatic BF
- Use Iso (preserves BF the best)
- Avoid PEEP (increases resistance to hepatic drainage, and remember that increased hepatic venous pressure will decrease hepatic perfusion pressure)
- Ensure normocapnia
- Lots of IV fluids
- Regional OK as long as no coag defects

2) Avoid hepatotoxic drugs or those that suppress the CYP450
- Tylenol
- Halothane
- Amiodarone
- Antibiotics (PCN, tetracycline, and sulfonamides)

Question 17

Effects of alcohol on GABA and NMDA receptors

Answer 17

Agonist at GABA

Antagonist at NMDA

Question 18

Early and late signs of alcohol withdrawl

Answer 18

Early: tremors and distorted perception (hallucinations and nightmares)

Late: Increased SNS activity (oh fuck, where’s my alcohol??), N/V, insomnia, confusion, and agitation

Question 19

Treatment of alcohol w/d

Answer 19

Alcohol, BBs, and A-2 agonists

Question 20

When do DTs present?

Answer 20

2-4 days without alcohol

- Grand mal seizures and combativeness

Question 21

Treatment of DTs

Answer 21

Diazepam or other benzos

BBs

Question 22

Consequence of portosystemic shunts

Answer 22

These shunts occur as blood tries to bypass the liver in high portal pressures.
This blood does not get filtered or processed by the liver, resulting in them remaining in circulation for a longer period of time

Question 23

MELD score looks at

Answer 23

3 things:

• Serum bilirubin
• Serum creatinine
• INR

Question 24

What are hepatopulmonary syndrome and portopulmonary HTN?

Answer 24

Hepatopulmonary syndrome
- Pulmonary vasodilation leads to increased R–>L shunting and hypoxia

Portopulmonary HTN

• Portal HTN + Pulmonary HTN
• PAP > 25