Jaundice Flashcards
What is jaundice?
It is the clinical sign of yellow discoloration of the sclera and the skin
When is clinical jaundice evident on babies skin?
-at 75 mmol/l
What is haemoglobin broken down into?
- haem
- globin by the reticulendothelial system (spleen)
What is the globin and haem broken up into?
Haem: biliverdin-then bilirubin
Globin: metabolized into amino acids
What is the bilirubin conjugated by in the liver?
-it is conjugated by glucocronic acid by the enzyme glucoronyl transferase
Is jaundice more common in formula fed or breast fed babies?
Breast fed
What is physiological jaundice?
- jaundice that occurs in more than half normal newborn babies.
- this is because they have increased amounts of unconjugated bilirubin
- this presents on day 2-3 and disappears within 7 days
What is physiological jaundice caused by?
-high haematocrit
-shorter red blood cell survival time which leads to high bilirubin production
Slow hepatic conjugation
-the enterohepatic circulation of bilirubin
How long can we expect babies to have clinical jaundice?
-2 weeks because of their immature liver
Which type of bilirubin crosses the BBB and is dangerous?
Free unconjugated bilirubin(not bound to albumin)
What parts of the brain are most susceptible?
- brain stem
- basal ganglia
- mid-brain
What is the clinical presentation of bilirubin encephalopathy?
- Severe jaundice (visible on hands and feet)
- Lethargy + poor feeding
- High pitched cry
- Setting sun appearance
- Death
How do we classify jaundice?
- Physiological-mild, transient in clinically well infants, does not require phototherapy
- Pathological
When should we suspect pathological jaundice?
- jaundice that presents in the first 24 hours of life
- jaundice that has been there for more than 14 days in a term infant and 21 days in a preterm baby
- jaundice that is too high above the phototherapy line
- conjugated jaundice
What are the causes of pathological jaundice?
- unconjugated jaundice
- Rh and ABO incompatibility
- infection, sepsis - Conjugated jaundice
- obstruction: choledochal cyst biliary atresia
- total parenteral nutrition
- cystic fibrosis
How do we test for jaundice?
- billicheck
- blood gas
What are the special investigations we do in these patients?
- Coombs test
- crp
- blood group test
- haemoglobin
What is the treatment for jaundice?
-phototherapy or exchange blood transfusion
What is the treatment for conjugated bilirubin?
-we need to address the underlying condition(biliary atresia, penicillin for syphillis for example)