Hepatic Pathophysiology Flashcards
What is the largest organ in the body?
Liver
The vascular capacity of the liver is what percent of total blood volume?
10-15%
The vascular capacity of the liver consists primarily of venous or arterial blood?
70% venous
Total hepatic bloodflow is what percent of the cardiac output?
25%
The vast majority of hepatic bloodflow goes through which vessel?
Portal vein 70-80%
Hepatic artery 20-30%
What is the functional microvascular unit of the liver?
Hepatic acinus
What are the four main components of the hepatic acinus?
Terminal portal venule
Hepatic arteriole
Bile duct
Lymph vessels and nerves
Describe the characteristics of hepatic bloodflow and resistance
High blood flow
low resistance
What is the normal amount of blood stored in the liver?
450 mL (10% TBV)
The liver contains what percentage of the body’s total lymph?
Half
Which vessel is primarily responsible for perfusing the liver?
The hepatic artery
What happens to the SVR, cardiac output, and arterial pressure in patients with liver disease?
Low SVR
Elevated cardiac output
Low arterial pressure
The ability of the hepatic artery to perfuse the liver is dependent upon what?
Systemic arterial pressure
True or false: splanchnic volume has a major role in the cardiovascular response to hypovolemia
True
Intrinsic regulation of blood flow in the liver is dependent upon what two factors?
- Autoregulation
- hepatic artery vasoconstricton - Metabolic control
- osmolarity
- arterial hypoxemia
- blood pH
Extrinsic regulation of hepatic bloodflow is dependent upon what two factors?
- Neural control
- vagus and splanchnic - Humoral factors
- vasoconstriction/dilation from hormones
All anesthetics and techniques that decrease cardiac output will do what to the total hepatic blood flow?
Produce a proportional decrease in hepatic bloodflow
What effect can upper abdominal surgery have on hepatic blood flow?
Can decrease blood flow up to 60%
What protein is a reliable predictor of chronic liver disease?
Serum albumin
All coagulation factors are produced in the liver except what?
Von Willebrand
What must happen to the liver function before coagulation is decreased?
Liver function must be significantly impaired
List the vitamin K dependent factors
II, VII, IX, X
What coagulation study is a good indicator of acute hepatic dysfunction as well as K dependent coagulation factor deficiencies?
Prothrombin time (PT)
What happens to amino acid metabolism in both acute and chronic hepatic disease?
It’s impaired
What is Bilirubin?
Byproduct of the breakdown of red blood cells in the spleen
-Conjugated in the liver so it can be excreted
How much yellow bile does deliver secrete per day?
500 to 1000 mL
What happens to the bile that is not secreted by the liver?
Stored in the gallbladder
What effect do narcotics have on bile formation?
All narcotics increase common bile duct pressure
What percent of insulin is degraded when passing through the liver?
50%
What is drug biotransformation?
Conversion of lipophilic substances to excretable metabolites
What is the major enzyme responsible for drug metabolism in the liver?
Cytochrome P450 (>90%)