Please enable JavaScript.
Coggle requires JavaScript to display documents.
gihep 21: bile + jaundice (ii) (newborn jaundice (treatments (UV therapy,…
gihep 21: bile + jaundice (ii)
jaundice intro
hyperbilirubinemia
35 micromol/L, but can go much higher
a.k.a icterus
yellow discolouration of skin,sclera,conjunctiva
can be conjugated or unconjugated depending on where damage/defect is
jaundice classification
prehepatic
bilirubin production > liver uptake capacity
excess haemolysis
unconjugated
a.k.a. haemolytic/haematogenous jaundice
intrahepatic
a.k.a. hepatic/hepatocellular jaundice
hepatocyte damage
biomarkers = high AST + ALT
unconjugated
posthepatic
obstruction to biliary flow (gallstones, cancer)
regurgitated into blood as can't get to SI
conjugated
a.k.a. obstructive/choleostatic jaundice
biomarkers = high alkaline phosphatase, no urobilin (in complete blockage)
newborn jaundice
unconjugated
causes: liver/liver enzymes not fully developed, haemolytic disease of newborn
! complications: kernicterus (bilirubin accumulates in brain + causes damage)
aggravating factors
sulphonamides (displace bilirubin from albumin)
novobiocin (inhibits glucuronlytransferase)
usually transient (resolves in 10 days)
shouldn't occur in 1st 24hrs (pathological if it does)
treatments
UV therapy
makes bilirubin non-toxic + H2O soluble
blood transfusion
maternal phenobarbitone
crosses placenta + induces synthesis of UDP-glucuronyl transferase
gilbert's syndrome
mild, fluctuating unconjugated hyperbilirubaemia
often with fasting/illness
50% genetic
affects males > females
onset: teens/20s/30s
causes
less udp-glucuronyl transferase activity
bilirubin uptake deficiency
treatment = low-dose phenobarbitone
Crigler-Najjar syndrome
extremely rare
recessive mutation in gene for UDP-glucuronyl transferase
severe unconjugated hyperbilirubinemia from birth
type 1 = complete absence
liver transplant by 5 y/o
type 2 = carrier = marked reduction
phenobarbitone + phototherapy
Dubin-Johnson syndrome + Rotor's syndrome
recessive
impaired biliary secretion
mutation in gene for MRP-2