GI pt. 2 Flashcards
(133 cards)
Hyperbilirubinemia
- elevated serum bilirubin
Jaundice/ Icterus
- yellowing of plasma/ tissues
Bilirubinuria
- bilirubin in urine (can be physiological in dogs, always abn in cats)
Cholestasis
- decreased bile flow
Icterus (Physical Exam)
- icterus most nosted in sclera, 3rd eyelid, pinnae, mucous membranes
- icterus detectable in tissues if serum bilirubin > 2mg/dl
3 Mechanisms of Icterus
- Pre-hepatic (hemolytic)
- Hepatic
- Post-Hepatic (obstructive)
Top Differentials for Pre-hepatic icterus
- IMHA (1 or 2)
- Heinz body anemia
- Infectious
- microangiopathic
Top Differentials for Hepatic Icterus (cats vs dogs)
Cats: - hepatic lipidosis - cholangitis - FIP - Lymphoma Dogs (cholestasis): - Cholangiohepatitis - chronic hepatitis - Cu-associated - cirrhosis
Top Differentials for Post-Hepatic Icterus
- obstruction (EHBDO)
- Rupture
Diagnostics for Icterus
- CBC
- Chem
- -> Pre - n cholesterol
- -> hepatic - low cholesterol
- -> Post - high cholesterol
- UA (bilirubinuria cats vs dogs)
- Ultrasound (hepatic vs post-hepatic)
- Other (coag, FNA, biopsy, CT scan)
Bile composition
- water, bile acids and salts, bilirubin, cholesterol, FA, electrolytes (bile released by CK)
- Bile acids - steroid acids made by liver
- Bile salts - salts of bile acids (Na/K)
Bile Functions
- fat emulsification and digestion
- absorption of fat-soluble vitamins
- bactericidal
- excretion of waste products (bilirubin and cholesterol)
2 surgical techniques for liver biopsy
- suture fracture technique
2. skin punch technique
Principle diagnostic feature of EHBDO
- hyperbilirubinemia
- high ALP, ALT< GGT
- hypoalbuminemia
- fecal exam - acholic feces, trematode eggs (Cats)
- bilirubin in the urine (maybe cysts)
Top 2 causes of EHBDO in feline
- Inflammatory (70%)
- Neoplastic (30%)
Indications for cholecystectomy in dogs
- biliary mucocele
- cholelithiasis
- GB neoplasia or trauma
- +/- functional EHBO but can catheterize
Dogs vs Cats Duodenal papilla differences
Dogs:
- major duodenal pappila –> exit for CBD + pancreatic duct separately
- minor duodenal pappila –> exit for accessory pancreatic duct
Cats:
- major duodenal pappila –> exit for conjoined CBD + PD
- minor duodenal pappila –> only 20% present
Understand bilirubin metabolism
- Spleen - breakdown heme to make biliverdin which is changed to unconjugated bilirubin
- unconjugated bilirubin is transported via blood + albumin to liver
- Liver - unconjungated –> conjugated bilirubin which is then secreted into bile in gallbladder
- Intestines - conj. –> urobilinogen which then gets excreted as stercobilin or reabsorbed and transported to liver or kidney
- liver pt2 - recycled
- kidney - excreted as urobilin in the urine
T/F: Icterus presents when bilirubin > 2mg/dL
T
Icterus:
Pre-hepatic = hemolysis (CBC)
Hepatic = intrahepatic cholestasis (Chem, n biliary u/s)
Post-hepatic = EHBDO or rupture (Chem, abn biliary u/s)
T
Blood Supply to Liver and Biliary Tract
Liver:
Hepatic Artery – (20% of blood and 50% of O2)
Portal Vein – (80% of blood and 50% of O2)
Biliary:
Cystic artery is a branch of the hepatic artery
T/F: the gallbladder lies between the quadrate and the right medial lobes of the liver.
T
Gall Bladder + Ducts Anatomy
Gall Bladder
Cystic Duct - gall bladder to first hepatic duct
Common bile duct - first hepatic duct to papilla
Feline megacolon
- middle aged, M > F
- a diagnosis of exclusion + radiographs
- Tx: Diet (canned diet), stool softeners, pro-kinetics, hydration, increase activity
- -> may require manual deopstipation under gen. anesthesia
- -> exhaust medical options prior to subtotal colectomy