Jaundice (Megan) Flashcards
what tests are best when assessing liver function?
INR (prothrombin time) and albumin levels.
What is the most common presentation of liver disease in children?
Jaundice
What do ALT and AST levels show?
These are elevated if you have damaged your heaptocytes
What do AP and GGT levels show?
These are elevated if you have a problem with your bile duct
What is the pathway for bilirubin metabolism?
- RBCs are broken down by the ER system.
- the haem part is broken down into biliverdin, this is converted into unconjugated bilirubin by biliverdin reductase.
- unconjugated bilirubin is bound to albumin and is taken to the liver where it is conjugated.
- its then excreted into the bile duct and into the intestines.
- in the small intestine its converted into urobilinogen, then in the gut its converted into stercobilin which gives stool its dark colour.
- some of the urobilinogen is excreted via the kidneys into the urine, and some is reabsorbed back through the liver to repeat the cycle.
what enzyme converts biliverdin into unconjugated bilirubin?
Biliverdin reductase.
How is unconjugated bilirubin conjugated?
with gluculuronic acid
At what ages is jaundice pathological?
<24 hrs
> 2 weeks (usually)
what is physiological jaundice?
Usually when the HbF has a shorter lifespan (80-90) and they are destroyed sooner and the immature liver can’t conjugate the bilirubin quick enough leading to unconjugated-bilirubin jaundice.
This doesn’t occur until AFTER the 1st day of life.
how long can breast milk jaundice occur for?
Up to 12 weeks of life (BUT if it begins after 2 weeks, or 3 weeks in pre term babies it should still be investigated).
who is allowed a longer threshold for jaundice?
babies who are breast fed usually have jaundice for longer than formula fed babies.
Term babies = allow 2 weeks before investigations.
Pre-term babies = allow 3 weeks before investigations.
who is allowed a longer threshold for jaundice?
babies who are breast fed usually have jaundice for longer than formula fed babies.
Term babies = allow 2 weeks before investigations.
Pre-term babies = allow 3 weeks before investigations.
what is a severe complication of increased levels of unconjugated bilirubin?
Kernicterus - the unconjugated bilirubin is fat soluble so can cross the blood brain barrier and deposit in the basal ganglia.
What are the effects of kernicterus?
Poor feeding
seizures
Cerebral palsy
Encephalopathy
what is a common therapy for unconjugated bilirubin?
Photo- therapy: it converts unconjugated bilirubin into water soluble so it can be excreted through the liver.
what are the main causes unconjugated jaundice?
physiological breast milk sepsis haemolysis hypothyroidism
what are the main causes of conjugated jaundice?
Biliary atresia
alpha 1 antitrypsen
viral hepatitis
what type of jaundice are early jaundices?
Mostly unconjugated
what type of jaundice is prolonged jaundice?
can be either conjugated or unconjugated
when is jaundice classified as prolonged?
> 2 weeks in term infants.
> 3 weeks in pre term infants.
what type of jaundice in babies is always abnormal?
Conjugated jaundice e- this suggests obstructive jaundice.
what type of jaundice in babies is always abnormal?
Conjugated jaundice e- this suggests obstructive jaundice.
what signs are always seen for obstructive jaundice?
Pale stools
dark urine
What is biliary atresia?
A congenital fibre-inflammatory disease of the bile ducts which starts distally then works its way proximally into the hepatic system.
Without treatment it leads to liver failure and death.
what does biliary atresia lead to?
increased levels of conjugated bilirubin.
Most common cause of liver transplant.
why is the urine dark in obstructive jaundice?
the conjugated bilirubin is still water soluble so can still be excreted through the kidneys and theres more of it
what investigations can be done for biliary atresia?
Split bilirubin
stool colour
ultrasound
liver biopsy
what is the treatment for biliary atresia?
Kasai Portoenterostomy (palliative) and usually winds up in liver transplant:
the gut is brought up to the liver and the bile is excreted direly into the bowel, with the stomach attaching to the bile further down.
what are the signs of biliary atresia?
pale stools
dark urine
symptoms persisting > 2 weeks
yellow skin
What is cholestasis?
decrease in bile flow due to impaired obstruction of hepatocytes or obstruction of bile through intra or extra hepatic ducts.
