Neonatology Flashcards
What is meant by physiological jaundice?
Jaundice is common in the neonatal period due to their high concentration of RBCs which are more fragile than adult and a less developed liver function .
RBCs breakdown and relates unconjugated BR, this accumulates causing mild yellowing of the san + sclera from days 2-7.
Usually resolves by 10days
What are the causes of neonatal jaundice?
PID
Physiological
Increased production
- Haemolytic disease of the newborn.
- ABO incompatibility
- haemorrhage
- intraventricular haemorrhage
- polycythemia
- sepsis + DIC
- G6PD Deficiency
Decreased clearance
- prematurity
- breast milk jaundice
- neonatal cholestasis
- extra hepatic biliary atresia
- endocrine disorders
- Gilbert syndrome
What timeline after birth is concerning with regard to jaundice?
Jaundice in the first 24hrs of life is pathological.
Neonatal sepsis is the most common cause.
Treat empirically for sepsis even if no other signs or risk factors.
Why are premature babies more likely to be more jaundiced?
Physiological jaundice is exaggerated due to immature liver.
Increased risk of complications e.g. kernicterus so important to monitor their BR levels
What is breast milk jaundice?
Some components of breast milk inhibit the ability of the liver to process BR. If a breast fed baby isn’t feeding adequately then more likely to become dehydrated and be slower to pass stool -> increased absorption of BR
What is haemolytic disease of the newborn?
ABO incompatibility typically the rhesus D antigen. If mum is Rh- and baby Rh+, antibodies can attach to metal RBCs causing the fetal immune system to attack their own RBCs -> haemolytic anaemia+ high levels of BR
What is considered prolonged jaundice?
more than 14days in full term babies and more than 21 days in premature babies.
This would prompt further investigation to look for an underlying cause such as biliary atresia, hypothyroidism, G6PD deficiency.
What investigations would you consider in a jaundiced newborn?
in first 24hrs - septic screen.
prolonged jaundice
Investigations
● FBC, blood film → polycythemia or anemia
● Conjugated BR → elevated levels indicated hepatobiliary cause
● Blood type testing of mother and baby for ABO or rhesus incompatibility
● Direct coombs test (direct antiglobulin test) for haemolysis
● Thyroid function especially hypo
● Blood + urine cultures if infection is suspected → sepsis needs abx
● G6PD deficiency levels
What is the management of neonatal jaundice?
The total BR levels are monitored and plotted on treatment threshold charts specific for Gest age at birth. If threshold reached - start treatment
Phototherapy is usually adequate (very high levels may need exchange transfusion).
How does phototherapy work?
Converts UC BR into isomers that can be excreted in the bile and urine without needing to be conjugated in the liver.
Important to have maximal skin exposure - UV light onto baby’s skin.
What is kernicterus?
Type of brain damage caused by excess BR levels
BR can cross the BBB and directly damage the CNS.
Baby may present - less responsive, floppy, drowsy, poor feeding.
The CNS damage is permanent -> cerebral palsy, learning disability, deafness.
