Hepatic Disease

Question 1

What contributes to the synthesis and biotransformation function of the liver?

Answer 1

Albumin
Clotting factors
Lactate

Question 2

What are the first-order kinetics of the liver?

Answer 2

Plasma drug concentration approx = elimination rate
Most anesthetics (prior to drug saturation)
Constant fraction of drug eliminated

Question 3

What are the zero-order kinetics of the liver?

Answer 3

Plasma drug concentration > elimination rate
After drug saturation, will change to zero-order
Constant amount of drug eliminated

Question 4

What is flow-dependent elimination?

Answer 4

Clearance of drug dependent
HBF = clearance
Changes in HBF result in changes in drug clearance
Most injectable anesthetics are flow-dependent

Question 5

What is capacity-dependent elimination?

Answer 5

Clearance of drug depends solely on liver enzymes
Enzyme capacity = clearance
Changes in HBF do not affect drug metabolism

Question 6

What is the result of the liver?

Answer 6

Drug elimination

Question 7

What are the sources of hepatic blood flow?

Answer 7

Portal vein: 75%

Hepatic artery: 25%

Question 8

What is a general rule in regards to HBF and anesthesia?

Answer 8

Most anesthetics decrease hepatic blood flow d/t general drop in CO, MAP

Question 9

What anesthetics tend to preserve hepatic arterial blood flow?

Answer 9

Less soluble inhalants (iso, sevo, des)

Question 10

What can a severe drop in CO/MAP result in?

Answer 10

Significant decrease in liver autoregulation/HBF

Question 11

What are signs of hepatobiliary disease?

Answer 11

Anorexia, depression, weight loss, vomiting, diarrhea, PU/PD
Organomegaly, ascites, edema, hyperbilirubinemia, jaundice, seizures
Coagulopathies**
Hepato-encephalopathy

Question 12

What is a clinical effect of hepatobiliary disease?

Answer 12

Elevated liver enzymes only with other problems

Question 13

What does severe liver failure result in?

Answer 13

Dysfunction of various components of liver contribution

Question 14

True or False: there is little to no correlation between liver enzymes and severity of liver disease

Answer 14

True

Question 15

How can you get lactate?

Answer 15

LRS: sodium lactate vs lactate as a proton donor (lactic acid)

Question 16

What conditions cause patients to have a worse morbidity and higher anesthetic risks?

Answer 16

Presence of any one:
Increased PT
Increased plasma bilirubin
Decreased albumin
Ascites

Question 17

True or False: there is no correlation between liver conditions and up-regulation of GABAa receptors

Answer 17

False, there is some

Question 18

What is albumin important for?

Answer 18

Colloidal osmotic pressure or oncotic pressure = 21-25 mmHg

Question 19

Is excess glucose administration beneficial with hypoglycemia?

Answer 19

No

Question 20

Why is hepatic disease and anesthesia a problem?

Answer 20

Couple anesthesia with other complicating factors:
Other potentially hepatotoxic 
Sepsis
Shock/hypotension
Severe anemia
CHF
Portosystemic shunts
Hepatic lipidosis