Liver disease & viral hepatitis Flashcards
What are the main functions of the liver?
glycogenolysis
cholesterol met, bilirubin met. urea cycle, steroid metabolism
gluconeogenesis
clotting factors, albumin, bile production
drug metabolism
what are the Phase I and phase II drug metabolism reactions
Phase I: oxidations by the cytochrome p450 systemic
Phase II: glucoronidation
WQhich labs can you look for liver function?
AST ALT ALk phos GGT T. Bilirubin albumin PT
When elevated, what do AST and ALT indicated?
hepatic necrosis
when elevated, what to Alk Phos and GGT indicate?
biliary obstruction if both are elevated
inc GGT can also indicat chorlnic liver disease
what is the normal value of AST
16-41 U/L
what is the normal level for ALT?
12-59 U/L
Normal value for Alk phos?
29-111 u/L
what is direct bilirubin and what does it mean when it is elevated?
Direct bilirubin= conjugated bilirubin which is elevated with bile duct obstruction or impaired intrahepatic excreition (hepatitis drugs, etc )(AFTER the liver)
what is indirect bilirubin and what does it mean when it is elevated?
Indirect bilirubin= unconjugated bilirubin is elevated in hemolysis (BEFORE the liver)
what is a normal albumin level? what does it mean when its is low or high?
3.4-4.7g/dL
i. If its low means that there is decreased hepatic synthetic capacity. Reasons it could be low: malnutrition, fluid overload, protein losing syndromes
ii. If it is high it can mean the person is dehydrated
what is the normal prothrombin time?
12 seconds
which clotting factors are made by the liver?
i. Major clotting factors 1,2,5, 7, 9, 10 are made in liver except 8
What does an elevated PT indicate?
problems with hepatic synthetic capacity
iii. Thrombocytopenia can occur due to portal hypertension and pooling in the spleen, decrease hepatic synthesis, and immune mediated destruction
what is the pathophysiology of cirrhosis?
i. when there is injury to hepatocytes, stellate cells, which reside in the sinusoid spaces start secreting collagen that lead to fibrosis in the sinusoid tissue. This fibrosis leads to increase in blood pressure of the portal vein. Additional changessucha ans changes in vasodilatory (NO) and vasocontricting (endothelin) mediators add to the pathophysiology
what are the main consequences of cirrhosis?
ascites, portal hypertension, esophageal vaircies, hepatic encephalopathy and coagulation disorders
what are the signs and symptoms of liver cirrhosis?
Weakness/fatigue, loss of appetite, diarrhea, abdominal pain the RUQ, yellow skin, dark urine or light clay colored stool
NVD
hypoalbuninemia, cogulaopathy, jaundice, glucose intolerance, hypolycmeia, hepatic encephalopathy, thrombocytopenia, inc AST, ALT, GGT
portal hypertension: esophageal/gastric varicies, splenomegaly, leukopenia/thrombocytopenia, ascites
what is the child-Pugh score and what is it used for ? What is the MELD score?
i. Quantifies the effects of cirrhosis in terms of labs and clinical manifestations. Usually when there are drug dosing adjustments for liver failure , you use this score.
ii. Both of the systems are used to define severity of cirrhosis, patient survival prediction, surgical outcome, risk of variceal bleeding
what are common causes for acute liver failure?
: viral hepatitis (HAV, HBV, EBV, CMV), drug induced APAP, INH, amanita phalloides mushroom, Wilson’s disease, Reye’s syndrome, toxins (CCL4, hydrazines), cryptogenic
what are examples of acute liver failure?
fulminant hepatic failure, subfulminant hepatic failure
what are common causes for chronic liver failure?
viral (HCV, HBV ), alcoholic cirrhosis, primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis, malignancy, cryptogenic
what is the general treatment approach in fulminant hepatic failure?
treat it depending on the symptoms that they are having
what is the definition of fulminant hepatic failure?
i. Hepatic encephalopathy within 8 weeks of onset of symptoms or within 2 weeks of the onset of jaundice. No prior history of liver disease
ii. Cerebral edema is common, portal hypertension complications are rare, can be reversible
what is the definition of subfulminant hepatic failure?
iii. Subfulminant is hepatic encephalopathy within 2 weeks and 3 months of onset of jaundice
what is tx for pts with fulminant hep failure and cerebral edema?
- Elevate head
- Mannitol
- Hyperventilate
what is tx for pts with fulminant hep failure and hypoglycemia?
d10w infusion
what is tx for pts with fulminant hep failure and coagulopathy ?
- Vitamin K (if deficient) : phytonadione (vit K) 10mg SQ daily x 3 days
- FFP (fresh frozen plasma for invasive procedures),
- factor VIIa
what is tx for pts with fulminant hep failure and GI bleed ?
stress ulcer prophylaxis: H2 blockers or omeprazole
what is tx for pts with fulminant hep failure and hepatic encephalopathy ?
avoid drugs that alter mental status and lactulose is not effective
what is hepatic encephalopathy and what is the proposed pathophys?
a. Syndrome characterized by AMS (confusion→ coma)
b. Accumulation of ammonia, production of false neurotransmitters, activation of GABA receptors, altered cerebral metabolism
what are the 4 stages of hepatic encephalopathy?
I. restlessness, forgetfulness, mild confusion
II. Drowsiness, lethargic, can’t perform mental tasks, disoriented, amnesia, ataxia, asterixis
III. Somnolent but arousable, unable to perform mental tasks, disoriented to time/place, incomprehensible speech
IV. comatose
what are the main treatment options for chronic hepatic encephalopathy? DOC?
lactulose =DOC
rifamixin- second line
neomycin
what is the non pharm Tx for HE
limit protain intake 0.81g/kg/day
avoid red meat, fish, vegtable protein the best
Lactulose
I= chronic HE
MOA: bacteria in the intestinal tract covert it to lactic and formic acid. The acidic environment causes NH3 from the blood to flow into the intestine and bind the acid. NH4+ cannot be absorbed back to blood because it is charged. There is an osmotic effect that draws water into the intestines (causing catharsis: diarrhea)
Dose:
a. ORAL 30ml po TID (concentration is 10g/15ml syrup. Titrate to mental status and 3-4 bowel mvment/day
b. IF it is stage III or IV, can give po or NG every 1-2 hours titatrated to mental status or 5-6 bowel movents /day
c. Other doses for enema available
SE: flatulence, bloating, diarrhea, hypernatremia, too sweet (can try kristalose)
Rifamixin
- MOA: antibiotic that is not well absorbed in the GI tract. Kills off Urease producing bacteria
- Dose: 550mg po bid or 400mg pot id
- SE: headache, flatulence, nausea, rash
neomycin
- MOA: aminoglycoside not well absorbed in the GI tract. Kills off urease producing bacteria
- Dose: 500mg po QID (2-4 g/day)
- SE: nephrotoxicity, ototoxicity
what is the pathophysiology of portal hypertension?
b. due to increased resistance to blood flow through the liver because of altered lobular and vascular architecture (fibrosisis in the sinusoids). Leads to back up in the portal vein. This leads to back up in the left gastric vein→ esophageal varices etc.
what defines portal hypertension?
> 10mmHG wedge hepatic vein pressure
what is the treatment approach for portal htn?
prevent the first bleeding episode (primary ppx), 2. Treat acute variceal bleeding 3. Secondary prophyalxis
what are the signs and symptoms of portal hypertension?
Splenomegaly esophageal varices Gastric varices portal hypertensive gastropathy hemorrhoids
what is the treatment for preventing bleeding from varices? doses?
Propranolol 20mg po tid max 320mg/day
nadolol 20mg-40 po daily max 40mg /day
normally you used nitrates with BB
what is the MOA in preventing bleeding from hemorrhage?
decreased cardiac output & vasoconstriction of splanchnic bed results in decreased portal blood flow
what are the nitrate doses for variceal bleeding prevention?
- Isosorbidide dinitrate 5-10mg pot id
2. Isosorbid monotintrated 15-30mg po daily