Unit 10 - Hepatobiliary Disorders Flashcards
How can you examine the liver?
Ask the patient to take a very deep breath
- diaphragm pushes liver downwards
What % of cardiac output goes to the liver?
25%
Of that 25%, how much of it is venous blood?
75 - 80% venous blood
- high in nutrients from the GI tract
- low in oxygen
Of that 25%, how much of it is arterial blood?
20 - 25% arterial blood
- high in OXYGEN
What is the vein that blood is able to flow to the liver?
Through the hepatic-portal vein
What are 5 examples of liver functions?
- Nutrient metabolism
- Production of serum proteins and enyzmes
- Drug and hormone metabolism
- Urea synthesis
- Bile synthesis
What is the main blood protein that is formed in the liver
Albumin
Why is biotransformation an important function of the liver?
Tylenol is not effective until it is BIOTRANSFORMED by the liver
- then it becomes active
What does the liver do to NH2?
Adds an H+ to yield NH3 (TOXIC)
- then coverts NH3 to urea to be safely excreted
What are the two possible fates of unconjugated bilirubin in the blood?
- Liver processes - converts to conjugated and excreted in bile
- Causes bilirubinemia, and results in jaundice
Why is it common for babies to experience jaundice?
Lots of cells are dying and the liver function hasn’t yet caught up to meet capacity
At what level does jaundice occur (mg/dl)?
Bilirubin level > 3 mg/dl
- normal is 0.2 - 1.2
What are the three causes of jaundice?
- Increased RBC breakdown
- nothing to do with the liver! - Impaired liver uptake of bilirubin
- Impaired excretion of bilirubin
What are the three types of jaundice?
- Prehepatic
- Hepatic
- Posthepatic
What is prehepatic jaundice caused by?
Increased levels of unconjugated bilirubin in blood
- jaundice happens before it reaches the liver
What is hepatic jaundice caused by?
Interference with the liver’s ability to conjugate bilirubin or to secrete it after conjugation
- can be unconjugated or conjugated
What is posthepatic jaundice caused by?
Obstruction of bile flow inside or outside of the liver
- gallstones!
- conjugated hyperbilirubinemia (backs up into the blood because the ducts are blocked = NOTHING wrong with the liver!)
What are the characteristics of indirect bilirubin?
- unconjugated
- elevated with increased RBC breakdown or impaired liver uptake
- bound by albumin
With indirect bilirubin, will it be found in the urine?
No - because it is bound by albumin
What are the characteristics of direct bilirubin?
- conjugated
- elevated with impaired excretion of bilirubin from liver
With direct bilirubin, will it be found in the urine?
Yes - because it is water-soluble
not bound to albumin
What is acute hepatitis?
Acute liver inflammation and cellular injury
What is acute hepatitis commonly caused by?
Hepatitis viruses (A, B, C, D, E) Hepatotoxins
What is the route of transmission for type B (and D) and C hepatitis?
Blood and bodily fluids
Is the prognosis more severe in B or C hepatitis?
B
How does acute hepatitis present?
- JAUNDICE
- anorexia
- fatigue
- diffuse abdominal discomfort
- dark urine
What is acute toxic hepatitis caused by?
Exposure to hepatotoxin
- or its metabolite
If alcohol is the toxin causing acute toxic hepatitis - what is the ratio of AST to ALT? What should it be normally?
2: 1
- usually the ratio is 1:1
What are the outcomes for viral hepatitis?
- Subclinical disease
- Acute icteric disease (could recover or lead to chronic hepatitis and then cirrhosis)
- Acute liver failure
Why is the incidence of Hepatitis B low in developed countries?
There is a vaccine
True or False:
Hepatitis B has worse outcomes than hepatitis C
False
- Type C is worse
- There is no vaccine for C
What is the etiology of chronic alcoholic liver disease?
Chronic, heavy alcohol exposure