Week 7 - Jaundice Flashcards
what is jaundice
- yellow discoloration to the skin & sclera of the eyes
what is another word for jaundice
- icterus
what causes jaundice
- elevated blood bilirubin ( can be unconjugated or conjugated)
what are the 3 types of jaundice
- prehepatic
- hepatic
- posthepatic
what is prehepatic jaundice
- jaundice caused by excessive RBC breakdown
list 4 common causes of prehepatic jaundice
- hemolytic transfusion rxn
- sickle cell anemia
- autoimmune/acquired hemolysis
- hemolytic disease of the newborn
what are the 4 characteristics of prehepatic jaundice
- indirect (free) hyperbilirubinemia (high unconj. bilirubin)
- no excess bilirubin in the urine
- decreased Hct
- normal colored stool
why do you get high lvls of uncong. bilirubin in prehepatic jaundice
- the excessive death of RBC causes excessive breakdown Hgb
- when Hgb is broken down, you get the formation of uncong. bilirubin
- this large amt of uncong. bilirubin overwhelms the hepatocytes & they cannot work fast enough to conjugate all the bilirubin
why is there no excess bilirubin in the urine during prehepatic jaundice? how will the urine appear?
- uncong. bilirubin is not water soluble = cannot go into the urine
- therefore, not getting any extra bilirubin in the urine
= amber urine
why do we have normal colored stools during prehepatic jaundice
- during prehepatic jaundice, your conjugated bilirubin isn’t being effected = still get bilirubin to the intestine
- bilirubin gives our stool its brown color
= normal colored stool
what is hyperbilirubinemia in the newborn
- by the 2nd or 3rd day of life, 60% of infants become jaundiced due to the natural breakdown fetal hgb and an immature liver that cannot handle all this uncong. bilirubin
how long does it take for hyperbilirubinemia to resolve in newborns
~ a week
how is hyperbilirubinemia of the newborn treated (3)
- fluids
- using bilitanks that utilize phototherapy
- exchange transfusions
when is jaundice of the newborn serious
- if it happens at birth or after 1 week or more
what can cause more serious types of newborn jaundice (5)
- breast feeding
- hemolytic disease (Rh+)
- hypoxia
- infection
- albumin binding drugs
how can breast feeding cause newborn jaundice
- if the milk contains an Ab that destroys RBC
what is hemolytic disease
- when an Rh- mother carries an Rh+ fetus
= mother creates antibodies that attack’s the fetus’ blood cells
what is a potential consequence of hyperbilirubinema of the newborn
- kernicterus
= brain damage r/t bilirubin
how does kernicterus occur?
- bilirubin is v toxic to the - brain
normally, bilirubin cannot cross the blood brain barrier - in newborns, the blood-brain barrier is weak & does not do a good job of keeping bilirubin out
what is an exchange transfusion
- removal of blood while that blood is replaced with donor blood
- blood in to replace RBC
- blood out to take out bilirubin
what is hepatic jaundiceq
- jaundice that involves problems with the liver, specifically the hepatocytes
1. impaired uptake of bilirubin by the liver
2. impaired conjugation of bilirubin
what are the 2 most common causes of hepatic jaundice
- hepatitis (inflammation or infection)
- cirrhosis
how does hepatitis & cirrhosis cause hepatic jaundice
- there is hepatocyte dysunfction r/t inflammation
= impaired conjugation & edema that interferes with bile secretion (intrahepatic cholestasis)
what is hepatic jaundice characterized by (4)
- uncong and cong hyperbilirubinemia
- dark urine
- N or pale stool
- elevated liver-specific enzymes in blood
why do we get both uncong and cong hyperbilirubinemia in hepatic jaundice
- the increased uncong would be due to impaired conjugation
- increased cong due to edema, which would block bile secretion (intrahepatic cholestasis)
why do we get dark urine in hepatic jaundice
- due to the increased cong bilirubin (water soluble)
why can we have either N or pale stool in hepatic jaundice
- pale if edema causes blockage of bile secretion
- N if no swelling
why do we have increased liver-specific enzymes in the blood during hepatic jaundice
- liver damage & inflammation = hepatocytes lyse or become permeable = release of enzymes
what genetic (inherited) disease can cause hepatic jaundice
- Gilbert’s disease
what is Gilbert’s disease
- a genetic disease that results in diminished activity in the enzyme responsible for conjugating bilirubin
- considered mostly harmless
what does Gilbert’s disease cause and how does this contribute to hepatic jaundice
= slowed conjugation = slight elevation in unconjugated bilirubin
what is posthepatic jaundice
- jaundice that occurs when bile flow is obstructed at any point between the liver & duodenom
describe how bile is excreted from the liver
- bile gets conjugated and leaves the liver via the bile duct
- it then goes to the gall bladder where it is stored
- then, bile is excreted from the gall bladder into the small intestine
what is bilirubin converted into in the intestine
- urobilinogen
- stercobilin
what is the fnxn stercobilin
- gives stool its color
what are 3 common causes of post hepatic jaundice
- bile duct strictures
- gall stones
- tumors
what is post hepatic jaundice characterized by (10)
- elevated conj bilirubin
- elevated or normal unconj bilirubin
- elevated blood cholestrol
- dark urine
- pale feces
- decreased urobilinogen & stercobilin
- steatorrhea
- accumulation of bile salts in the blood & depositing in the skin
- vitamin K defic
- elevated liver enzymes ( may or may not happen)
why do we get elevated conjugated & unconj bilirubin in post hepatic jaundice
- conj = due to backflow, can’t get rid of conj bilirubin in the
- unconj = ???
what is the function of urobilinogen
- some reabsorbed back into portal circulation & returned liver
- small amt released in urine
why do we get dark colored urine in post hepatic jaundice
- increased conjugated bilirubin
- since the bilirubin cannot leave the bile duct, it is excreted thru the kidneys instead (???)
why do we get pale colored feces in post hepatic jaundice
- due to decreased stercobilin
why do we get steatorrhea in post hepatic jaundice
- bile is responsible for emulsifying fat which allows fat to be absorbed
- if fat cannot be emsulified, we wont absorb it & it is lost in the feces
what does the depositing of bile salts in the skin during post hepatic jaundice cause
- puritis
why do we get vitamin K deficiency during post hepatic jaundice
- it is a fat soluble vitamin
- therefore, no bile = cannot emsulfy & absorb
what are types of fat soluble vitamins
A, D, E, K
what does vitamin K deficiency cause
= decreased clotting factor production
= abnormal bleeding
