Flashcards in Hepatic Pathophysiology Deck (78):
What is the largest organ in the body?
The vascular capacity of the liver is what percent of total blood volume?
The vascular capacity of the liver consists primarily of venous or arterial blood?
Total hepatic bloodflow is what percent of the cardiac output?
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?
What are the four main components of the hepatic acinus?
Terminal portal venule
Lymph vessels and nerves
Describe the characteristics of hepatic bloodflow and resistance
High blood flow
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?
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?
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
Intrinsic regulation of blood flow in the liver is dependent upon what two factors?
-hepatic artery vasoconstricton
2. Metabolic control
Extrinsic regulation of hepatic bloodflow is dependent upon what two factors?
1. Neural control
-vagus and splanchnic
2. 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?
All coagulation factors are produced in the liver except what?
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?
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?
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%)
When looking at lab tests, Which enzyme is related to the bile ducts and is often increased when they're blocked?
Which enzyme is mainly found in the liver and is the best test for detecting hepatitis?
Alanine transaminase (ALT)
Name two other liver enzyme tests that are less specific
Aspartate transaminase (AST)
Gamma-glutamyl transpeptidase (GGTP)
What happens to serum albumin levels in chronic liver disease?
They are decreased
What is the normal range for Prothrombin time?
9 to 12, 10-15 sec
What can happen when serum albumin is decreased?
Can cause reduced intravascular osmotic pressure and cause vascular leak leading to edema formation and ascites
What is the normal range for serum albumin
Coumadin interferes with which factors?
Vitamin K dependent
Jaundice is caused by what?
Increased total Bilirubin
What are some possible causes of elevated serum bilirubin?
Obstructed bile duct
If total Bilirubin is elevated but direct Bilirubin is normal what is the problem?
Excess unconjugated Bilirubin due to problem in upstream excretion
If direct Bilirubin is elevated then what is the problem?
The liver is unable to secrete it normally because of a bile duct obstruction
What is the normal range for total Bilirubin?
0.2 to 1.5 mg/dL
Sorry there are so many freaking questions
This is a long ass lecture
How is hepatitis A transmitted and how does it manifest clinically?
Manifests as acute viral hepatitis
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
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)
Which form of hepatitis requires a co-infection with another form of hepatitis?
Hepatitis D can progress to fulminant hepatitis or cirrhosis
Which form of hepatitis poses the greatest occupational risk for anesthesia care providers?
B, but there's a vaccine. Don't freak.
What effect does hepatic dysfunction have on anesthetic drugs?
Benzodiazepines, opioids & NMBs have a prolonged effect
Cirrhosis is a chronic disease of the liver characterized by what?
Distortion of the normal hepatic structure or scarring caused by cellular destruction
What are some of the main complications associated with cirrhosis of the liver?
Portal vein hypertension
The formation of calculus stones in the gallbladder caused by cholesterol crystal precipitation is known as...
Inflammation of the gallbladder caused by a gallstone in the cystic duct that connects to the hepatic duct is known as...
A patient coming in for a cholecystectomy will commonly require what type of induction?
RSI --- recent history of N/V
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
An elevation in unconjugated bilirubin can cause seizures and brain damage a condition known as
What is the most common neoplasm of the liver?
Metastasis from another site
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
Define portal hypertension
A sustained elevation of pressure in the portal vein above the normal level of 6 to 12 cm H2O
What two factors commonly combine to overflow the portal circulation?
Decreased outflow and increased inflow
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
What are some examples of post hepatic (hepatic vein) portal hypertension?
Budd-Chiari syndrome, Right-sided heart failure, Restrictive cardiomyopathy, Constrictive pericarditis)
What is a common cause of intrahepatic portal hypertension?
What is a cause of pre-hepatic (portal vein) portal hypertension?
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
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
What is ascites and what is it often caused by?
It is the accumulation of serous fluid in the peritoneal cavity
2. Portal hypertension
3. Increased lymph production and flow
4. Sodium retention
5. Impaired water excretion
7. Decreased colloid osmotic pressure
What is an important anesthetic consideration when decompressing the fluid of ascites?
Expansion of a very large venous reservoir leading to potentially severe hypotension
Patients with ascites often have what type of arterial blood gas results?
How is ascites treated?
Induced diuresis with spironolactone but diuresis of ascitic fluid should not exceed 1 L per day for fear of hypovolemia
Most patients in advanced hepatic failure have some degree of coagulopathy. What is the main stay treatment for this?
Administration of fresh frozen plasma
What is the purpose of monitoring clotting tests intraoperatively?
Confirm that what you're doing is working and you're not fucking shit up
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
How does Hepatic encephalopathy manifest?
Asterixis (penguin flap)
Fector hepaticus (sweet breath)
Pre-operative encephalopathy (88% mortality)
What are some causes of hepatic encephalopathy?
Protein breakdown products