Disorders of the Liver Part 1 Flashcards
What are the 4 lobes of the liver and what separates them?
- Anteriorly: Right lobe and left lobe by falciform ligament.
- Posteriorly: Anterior and posterior caudate via porta hepatis
What are the 3 components of the porta hepatis?
- Hepatic portal vein
- Hepatic artery
- Common Hepatic duct
Not the same as a portal triad
What are the two vessels that supply hepatocytes?
- Venous blood via portal vein
- Oxygenated blood via hepatic arteries
What is the flow of blood beginning at a portal vein?
- Portal veins
- Sinusoids
- Central Veins
- Hepatic Veins
- IVC
What two lipoproteins are made by hepatocytes?
- VLDL
- HDL
What is bilirubin from?
End product of the breakdown of an RBC, created as unconjugated/indirect/lipid soluble bilirubin
Breakdown of heme to protoporphyrin to bilirubin
UCB = unconjugated bilirubin
What binds to UCB and takes it to the liver?
Albumin
What enzyme is used to conjugate bilirubin?
Uridine glucuronyl transferase = UGT
What happens to bilirubin once it is conjugated?
- Transported down bile canaliculi to bile ducts
- Deposited within the gallbladder at direct/conjugated bilirubin
It is now water soluble.
What converts CB to urobilinogen and what happens to it?
- Microbes convert it to UBG.
- UBG can either become stercobilin into your poop (giving it color)
- It can also become urobilin and get excreted via the kidneys or goes back to the liver
What is jaundice?
- Product of heme metabolism
- Accumulation of bilirubin
How elevated is serum total bilirubin to give skin a yellow discoloration?
Usually greater than 2.5mg/dL
Would pre-hepatic jaundice present with higher UCB or CB?
UCB
How do bilirubin levels look in pre-hepatic jaundice?
Increased UCB in serum due to RBC hemolysis
aka hemolytic anemias
How can bilirubin levels vary in hepatic jaundice?
- Increased UCB in serum due to hepatocyte impairment
- Increased CB in serum due to hepatic duct obstruction
How do bilirubin levels look in post-hepatic jaundice?
- Increased CB in serum due to biliary tract obstruction
- Decreased bilirubin in gut = pale/acholic stool and no UB in urine
What clinical findings are most suggestive of elevated UCB?
- Normal stool and urine color
- Mild jaundice
- No bilirubin in urine
- Splenomegaly (Except in SCD)
What clinical findings are most suggestive of elevated CB?
- Pruritis and jaundice
- Light colored stools
- Malaise, anorexia, low-grade fever, RUQ, Dark urine
- Hepatomegaly, spider telangiectasias, palmar erythema, ascites, gynecomastia, sparse body hair
- Varies based on liver dysfunction
What is the term for light colored stool?
Acholic stool
What clotting factors are NOT affected in liver disease?
- III
- IV
- VIII
What does Vit K require to be absorbed from the GI tract?
Bile
What CBC count will be lower in liver disease?
Thrombocytopenia
TPO is made in the liver
What are the 3 common CBC abnormalities seen in liver disease?
- Thrombocytopenia
- Leukopenia
- Anemia
EPO is made in both the kidneys and liver
What carrier protein does the liver make?
Albumin
What is the underlying mechanism behind portal HTN?
Blockkage in blood flow through the liver, resulting in cirrhosis most commonly.
What is the gold standard to diagnose portal HTN?
IVC catheter to measure hepatic venous pressure
What are the clinical manifestations of portal HTN?
- Splenomegaly
- Esophageal varices
- Hemorrhoids
- Caput Medusae
What are the main veins implicated in portal HTN?
- Esophageal veins
- Paraumbilical veins
- Superior mesenteric veins
- Inferior mesenteric veins
- Middle rectal veins
- Inferior rectal veins
What are the ABCDEs of Portal HTN?
- Ascites
- Bleeding
- Caput Medusae
- Diminished liver function
- Enlarged spleen
What is the MCC of ascites?
Cirrhosis
What are the underlying mechanisms of ascites?
- Underfill due to lack of albumin and shift of fluid
- Overflow due to increased pressure
- Impairment of RAAS
What is the MC organism that causes spontaneous bacterial peritonitis?
E. Coli
Why does hepatorenal syndrome occur?
- Arterial vasodilation in splanchnic circulation due to Portal HTN
- More NO is made, vasodilating more and causes a fall in CO
- Kidneys become poorly perfused
- Acute renal failure ensures
What causes pruritis in liver disease?
Bile salts
What are spider nevi and palmar erythema due to?
Excess estrogen
What can happen specifically to males with liver disease? Females?
- Males: testicular atrophy & gynecomastia due to impaired cholesterol synthesis
- Females: Menstrual irregularities due to excess estrogen
What is the severe manifestation of liver disease?
Hepatic encephalopathy due to buildup of ammonia
Confusions, tremors, coma
What are the components of a LFT/hepatic panel?
- Total protein
- Albumin
- Total bilirubin
- Direct bilirubin
- AST/SGOT
- ALT/SGPT
- ALP
- GGT
- PT/PTT
- Cholesterol
- BUN
- Hepatitis Panel
Bolded are addons
What are the two serum aminotransferases?
- Alanine aminotransferase (ALT/SGPT)
- Aspartate aminotransferase (AST/SGOT)
What liver enzymes measure hepatocyte damage?
- AST/ALT
- LDH
Which liver enzyme is most specific for hepatocellular damage if markedly elevated?
ALT
AST is found in heart and skeletal muscle too.
ALT has a L, so its the most Liver specific
Acute Liver Trouble
What do significant elevations of ALT and AST associate the most with?
Hepatocellular damage
8-25x = acute damage
In general, what does an acute liver damage present as in terms of the aminotransferases enzymes? Chronic?
- Acute: ALT > AST (8-25x ULN)
- Chronic: AST > ALT (< 8x ULN)
ALT = Acute Liver Trouble
What does a moderate elevation of AST > ALT of around 2 or more suggest?
Chronic alcoholic liver disease
What does a moderate elevation of AST > ALT of around 1-1.99 suggest?
Chronic NASH/non alcoholic cirrhosis
What elevates LDH?
Any cellular damage in general. Non-specific test.