Hepatic Pathophysiology Flashcards Preview

AP: Cumulative > Hepatic Pathophysiology > Flashcards

Flashcards in Hepatic Pathophysiology Deck (78):
1

What is the largest organ in the body?

Liver

2

The vascular capacity of the liver is what percent of total blood volume?

10-15%

3

The vascular capacity of the liver consists primarily of venous or arterial blood?

70% venous

4

Total hepatic bloodflow is what percent of the cardiac output?

25%

5

The vast majority of hepatic bloodflow goes through which vessel?

Portal vein 70-80%

Hepatic artery 20-30%

6

What is the functional microvascular unit of the liver?

Hepatic acinus

7

What are the four main components of the hepatic acinus?

Terminal portal venule
Hepatic arteriole
Bile duct
Lymph vessels and nerves

8

Describe the characteristics of hepatic bloodflow and resistance

High blood flow
low resistance

9

What is the normal amount of blood stored in the liver?

450 mL (10% TBV)

10

The liver contains what percentage of the body's total lymph?

Half

11

Which vessel is primarily responsible for perfusing the liver?

The hepatic artery

12

What happens to the SVR, cardiac output, and arterial pressure in patients with liver disease?

Low SVR
Elevated cardiac output
Low arterial pressure

13

The ability of the hepatic artery to perfuse the liver is dependent upon what?

Systemic arterial pressure

14

True or false: splanchnic volume has a major role in the cardiovascular response to hypovolemia

True

15

Intrinsic regulation of blood flow in the liver is dependent upon what two factors?

1. Autoregulation
-hepatic artery vasoconstricton
2. Metabolic control
-osmolarity
-arterial hypoxemia
-blood pH

16

Extrinsic regulation of hepatic bloodflow is dependent upon what two factors?

1. Neural control
-vagus and splanchnic
2. Humoral factors
-vasoconstriction/dilation from hormones

17

All anesthetics and techniques that decrease cardiac output will do what to the total hepatic blood flow?

Produce a proportional decrease in hepatic bloodflow

18

What effect can upper abdominal surgery have on hepatic blood flow?

Can decrease blood flow up to 60%

19

What protein is a reliable predictor of chronic liver disease?

Serum albumin

20

All coagulation factors are produced in the liver except what?

Von Willebrand

21

What must happen to the liver function before coagulation is decreased?

Liver function must be significantly impaired

22

List the vitamin K dependent factors

II, VII, IX, X

23

What coagulation study is a good indicator of acute hepatic dysfunction as well as K dependent coagulation factor deficiencies?

Prothrombin time (PT)

24

What happens to amino acid metabolism in both acute and chronic hepatic disease?

It's impaired

25

What is Bilirubin?

Byproduct of the breakdown of red blood cells in the spleen
-Conjugated in the liver so it can be excreted

26

How much yellow bile does deliver secrete per day?

500 to 1000 mL

27

What happens to the bile that is not secreted by the liver?

Stored in the gallbladder

28

What effect do narcotics have on bile formation?

All narcotics increase common bile duct pressure

29

What percent of insulin is degraded when passing through the liver?

50%

30

What is drug biotransformation?

Conversion of lipophilic substances to excretable metabolites

31

What is the major enzyme responsible for drug metabolism in the liver?

Cytochrome P450 (>90%)

32

When looking at lab tests, Which enzyme is related to the bile ducts and is often increased when they're blocked?

Alkaline phosphatase

33

Which enzyme is mainly found in the liver and is the best test for detecting hepatitis?

Alanine transaminase (ALT)

34

Name two other liver enzyme tests that are less specific

Aspartate transaminase (AST)
Gamma-glutamyl transpeptidase (GGTP)

35

What happens to serum albumin levels in chronic liver disease?

They are decreased

36

What is the normal range for Prothrombin time?

9 to 12, 10-15 sec

37

What can happen when serum albumin is decreased?

Can cause reduced intravascular osmotic pressure and cause vascular leak leading to edema formation and ascites

38

What is the normal range for serum albumin

3.9-5.0 g/dl

39

Coumadin interferes with which factors?

Vitamin K dependent

40

Jaundice is caused by what?

Increased total Bilirubin

41

What are some possible causes of elevated serum bilirubin?

Viral hepatitis
Obstructed bile duct
Cirrhosis

42

If total Bilirubin is elevated but direct Bilirubin is normal what is the problem?

Excess unconjugated Bilirubin due to problem in upstream excretion

43

If direct Bilirubin is elevated then what is the problem?

The liver is unable to secrete it normally because of a bile duct obstruction

44

What is the normal range for total Bilirubin?

0.2 to 1.5 mg/dL

45

Sorry there are so many freaking questions

This is a long ass lecture

46

How is hepatitis A transmitted and how does it manifest clinically?

Fecal/oral route
Manifests as acute viral hepatitis

47

How is hepatitis B transmitted and how does it manifest clinically?

Transmitted by blood exchange or sexual contact

Manifests as acute with development to fulminant hepatitis and rapid liver destruction

48

How is hepatitis C transmitted and how does it manifest clinically?

Transmitted by blood exchange or sexual contact
Manifests as acute hepatitis
(50% will get chronic
20% will develop cirrhosis)

49

Which form of hepatitis requires a co-infection with another form of hepatitis?

Hepatitis D can progress to fulminant hepatitis or cirrhosis

50

Which form of hepatitis poses the greatest occupational risk for anesthesia care providers?

B, but there's a vaccine. Don't freak.

51

What effect does hepatic dysfunction have on anesthetic drugs?

Benzodiazepines, opioids & NMBs have a prolonged effect

52

Cirrhosis is a chronic disease of the liver characterized by what?

Distortion of the normal hepatic structure or scarring caused by cellular destruction

53

What are some of the main complications associated with cirrhosis of the liver?

Portal vein hypertension
Varices
Ascites

54

The formation of calculus stones in the gallbladder caused by cholesterol crystal precipitation is known as...

Cholelitiasis

55

Inflammation of the gallbladder caused by a gallstone in the cystic duct that connects to the hepatic duct is known as...

Cholecystitis

56

A patient coming in for a cholecystectomy will commonly require what type of induction?

RSI --- recent history of N/V

57

An average unit of packed red blood cells contains approximately how much bilirubin? This load increases or decreases with age of unit?

250 mg of Bilirubin
Increased in older units

58

An elevation in unconjugated bilirubin can cause seizures and brain damage a condition known as

Kernicterus

59

What is the most common neoplasm of the liver?

Metastasis from another site

60

During a hepatic resection, how must you maintain a patient's volume status?

Relatively hypovolemic to minimize venous engorgement of the liver and blood loss

61

Define portal hypertension

A sustained elevation of pressure in the portal vein above the normal level of 6 to 12 cm H2O

62

What two factors commonly combine to overflow the portal circulation?

Decreased outflow and increased inflow

63

Back pressure in the portal system can lead to what other complication in another organ?

It causes splenomegaly and is partly responsible for the accumulation of ascites in the abdomen

64

What are some examples of post hepatic (hepatic vein) portal hypertension?

Budd-Chiari syndrome, Right-sided heart failure, Restrictive cardiomyopathy, Constrictive pericarditis)

65

What is a common cause of intrahepatic portal hypertension?

Cirrhosis

66

What is a cause of pre-hepatic (portal vein) portal hypertension?

Thrombosis

67

Bleeding of varices (G.I. bleeding) is often indicative of what?

You're going to have a shitty day
And your patient has severe hepatic obstruction and portal hypertension

68

What is the TIPS procedure and why is it used?

Transjugular intrahepatic portosystemic shunt (TIPS) is used as a way to decompress the portal circulation and buy some time in the course of the underlying liver disease

69

What is ascites and what is it often caused by?

It is the accumulation of serous fluid in the peritoneal cavity
1. Cirrhosis
2. Portal hypertension
3. Increased lymph production and flow
4. Sodium retention
5. Impaired water excretion
6. Hypoalbuminemia
7. Decreased colloid osmotic pressure

70

What is an important anesthetic consideration when decompressing the fluid of ascites?

Expansion of a very large venous reservoir leading to potentially severe hypotension

71

Patients with ascites often have what type of arterial blood gas results?

Arterial hypoxemia

72

How is ascites treated?

Induced diuresis with spironolactone but diuresis of ascitic fluid should not exceed 1 L per day for fear of hypovolemia

73

Most patients in advanced hepatic failure have some degree of coagulopathy. What is the main stay treatment for this?

Administration of fresh frozen plasma

74

What is the purpose of monitoring clotting tests intraoperatively?

Confirm that what you're doing is working and you're not fucking shit up

75

The greatest fear of massive blood loss in the coagulopathic patient is what? (According to Dr. B)

The breakdown of the clotting process (fibrinolysis).....
I'd probably go with death

76

How does Hepatic encephalopathy manifest?

Mental confusion
Asterixis (penguin flap)
Fector hepaticus (sweet breath)
Pre-operative encephalopathy (88% mortality)

77

What are some causes of hepatic encephalopathy?

Cerebral intoxication
Protein breakdown products
Ammonia

78

How is hepatic and encephalopathy treated

Protein restriction
Gut antibiotics
Reduced diuretics
Treat hypokalemia
Restrict sedatives