Pathophysiology Acute Liver Failure Flashcards
What is the tx for all cases of acute liver failure?
transplant
What is fulminant hepatic failure?
aka acute liver failure, a syndrome of massive necrosis of liver cells without preceding liver disease (i.e. complete failure occuring within 8 weeks of onset of disease)
How deadly is ALF?
•66% mortality!!! Get to transplant
What are the causes of ALF?
- viral
- drug and toxin (Viral and toxic account for 75% of cases)
- ischemic
- metabolic
What are the possible viral causes of ALF?
•A(rare), B, D (gotta have B), E(pregnant), Herpes (immuncompromised), CMV, EBV (uncommon), Varicella, Adeno
What are the main drug causes of ALF?
Acetaminophen, Halothane, NSAIDS, Herbals
Isoniazid
Mushroom poisoning
Alcohol
What are some ischemic precipitators of ALF?
•Shock (prolonged hypotension/heat-stroke), Budd-Chiari (OCs= clots in hepatic veins)
What are some metabolic causes of ALF?
•Wilson (chronic but present acutely),
Fatty Liver of Pregnancy (abortion needed),
Reye’s Syndrome
What is the most common viral cause of ALF?
Hep B
Most examples of hepatotoxicity caused by drugs occur when?
within the first 4 to 8 weeks of beginning use.
Describe the metabolism of acetaminophen?
Acetaminophen in therapeutic doses undergoes sulfation and glucuronidation (phase II reactions) but is metabolized by cytochrome P450 2E1 (phase I reaction) to N-acetyl-p-benzoquinoeimine (NAPQI) if the capacity of the phase II reactions is exceeded or if the cytochrome is induced.
Glutathione-S-transferase (GSH) is capable of detoxifying NAPQI to mercapturic acid if glutathione is available.
Hypotension can cause ALF. What are some common sources?
- Surgical shock
- Cardiac Failure
- Septic Shock
Hemolysis with Hepatic Failure is highly suggestive of what?
Wilson Disease. Wilson’s is genetically determined and usually presents before age 35.
T or F. Malignant infiltration of the kidneys can also cause ALF
T. In cases of lymphoma, CML, small cell carcinoma of the lung, etc.
Acute hepatitis B is characterized by what serology wise?
a positive surface antigen test (HBsAg) and a positive core antibody test (anti-HBc)
What is the first serologic marker to appear in Hep B infection?
HBsAg. ·Indicator of ongoing infection
·Presence does not correlate with viral load or severity of infection
·Persistence of HBsAG for 6+ months indicates what?
chronic infection
Anti-HBc (Antibody to hepatitis B core antigen) indicates what?
prior infection at some undefined time
· IgM indicates recent infection
· Not associated with recover or immunity