Liver- Disease Flashcards
1
Q
What is associated with acute liver disease? Most common cause?
Chronic? Most common cause?
A
- Acute- elective surgery has high M&M
- encephalopathy- req ICP management
- Coagulopathy (INR > 1.5)
- No history of liver disease
- illness <26 weeks to be considered acute
- most common: acetaminophen toxicity
- Chronic
- Hepatic inflammation and necrosis continued for >6 months
- need liver biopsy for grading (inflammation and necrosis)
- most common: HBV, HCV, and autoimmune
2
Q
What are the five types of viral hepatitis?
A
- **Varied presentation ranging from asymptomatic to acute hepatic failure
- flue like symptoms, malaise, muscle pain, jaundice, dark urine
- Hep A- enteric, contaminated food
- usually get better after 21 days if previously healthy
- Hep B (50% of US cases)
- Bodily fluids, IV drug abuse
- Hep C (30% of US cases)
- sexually transmitted, needlesticks
- Hep D (20% of US cases)
- RNA strand requires Hep B at same time
- Hep E- similar to hep A
- Miscellaneous causes- CMV, epstein Barr, Herpes
3
Q
Toxin and drug-induced hepatitis
What is directly toxic?
What cause idiosyncratic reactions?
A
- Directly toxic:
- carbon tetrachloride
- acetaminophen- tx with N-acetylcysteine
- alpha-amanitin (toxic mushroom)- tx with HD
- Idiosyncratic reactions: unpredictable and not dose dependent
- NSAIDS
- VA
- anti-HTN meds
- anticonvulsants
4
Q
VA induced hepatitis:
How does it present?
What are risk factors?
A
- Presentation:
- fever
- anorexia
- nausea
- chills
- myalgias
- rash
- fever
- arthralgia
- eosinophilia followed by jaundice 3-6 days later
- Risk factors:
- PRIOR EXPOSURE!
- >40 yrs old
- obesity
- female
- mexiican ethnicity
- multiple brief procedures within brief duration of time
- enzyme induction
5
Q
VA induced hepatitis:
What causes it?
A
- Immune theory
- Cytochrome P450 2EI oxidizes each anesthetic (exc Sevo) to yield highly reactive (toxic) intermediates that bind covalently (acetylation) to a variety of hepatocellular macromolecules
- Altered hepatic proteins may trigger an immunologic response that causes massive hepatic necrosis
- Causes halothane hepatitis
6
Q
How much of each VA is hepatically metabolized?
KNOW THIS! Board question!
A
- Halothane 20-46%
- Enflurane 2.5-8.5%
- Sevoflurane 2-5%- NOT going to cause halothan hepatitis
- Isoflurane 0.2-2%
- Desflurane 0.02%
7
Q
How do the VA affect hepatic blood flow?
A
- HBF and oxygenation decrease with general anesthesia with VA
- Halo > Enfl > Des > Iso > Sev
- Decreased CO and stress response = catecholamine induced vasoconstriction (???)
- Metabolic demands do decrease, improving the supply demand balance
8
Q
How does N2O affect HBF and oxygen delivery?
A
- Increase in SNS activity = mild vasoconstriction of splanchnic vasculature (decreased portal flow) and hepatic arterial system
- inhibition of methionine synthase activity
- prolonged exposure leads to B12 deficiency
- No concrete evidence it causes hepatic toxicity if supply-demand O2 is normal
- does cause hepatic disease in providers that use it often
9
Q
How do IV anesthetics affect HBF and O2 delivery?
A
- only have modest impact on HBF and no meaningful adverse influence on postoperative liver function when BP is maintained
- Opioids increase tone of CBD and SOO
- also increase number of phasic contractions leading to increased biliary tract pressure and spasm
10
Q
How does neuraxial anesthesia affect HBP and O2 delivery?
A
- HBF decreases during spinal and epidural anesthesia parallel to reductions in BP
- Reduced PBF and unchanged HABF causes a decrease in THBF
- Changes may NOT be reversed with fluids and vasopressors
- vasopressors may drop splanchnic blood forr wihich will further reduce portal blood flow
11
Q
What are other causes of peri-operative liver dysfunction?
A
- Inflammation and sepsis- less blood flow to liver, but liver is producing the inflammatory mediators….set up for failure
- hypoxia and ischemia
- cardiac disease
- surgical stress
12
Q
What is nonalcoholic fatty liver disease?
A
- Most common US chronic liver disease
- associated with DM II and obesity
- Bariatric surgery often improves
- Fat accumulation in liver >5% of weight
- may have increased M&M with abdominal procedures
- Sx range from asymptomatic to cirrhosis
13
Q
What are the different types of alcoholic liver disease?
A
- Steatosis- caused by binge drinking; if they stop they will recover (Octoberfest)
- Alcoholic hepatitis
- Cirrhosis
- ***alcohol abusers have a 2-3x increase in peri-op morbidity
14
Q
What is cirrhosis?
Sx?
A
- Parenchymal liver disease
- Most commonly caused by HCV and alcoholism
- Chronic inflammation/necrosis results in fibrotic changes
- Sx:
- anorexia
- weakness
- N&V
- abdominal pain
- hepatosplenomegaly
- ascites
- varices
- jaundice
- spider nerves
- metabolic encephalopahty
- EVERY organ and body system is altered
15
Q
What are the hepatic vascular abnormalities seen in cirrhosis?
A
- Hallmark of end-stage cirrhosis = portal HTN
- Portal HTN results in porto-systemic collaterals which develop by dilation and hypertrophy of existing vascular channels
- Ascites
- hepatic encephalopathy
- varices
- susceptibility to bacterial infections
- altered drug metab
20
Q
Explain the flow chart of Cirrhosis-induced portal hypertension
A
