Neonatal Jaundice Flashcards
What is the definition of neonatal jaundice?
- 80-120μmol/L
- Serum bilirubin
- which causes yellowing of the skin and sclera
What should be asked in a jaundice history?
- Onset, change?
- Feeding - breastfeeding? bottle fed? amount, frequency
- Wet & dry nappies - change in colour ?dark urine, pale stool or frequency?
PMHx:
- antenatal scans normal?
- prerinatal GBS, mat infections? Rh status / presence of antibodies?
- postnatal - baby well since birth?
What should be included in examination / bloods of neonates with jaundice?
weight and exam
bloods: TFT + urine now checked @5d heel prick test; do FBC + bilirubin
NB: hypothyroid = dc bilirubin conjugation rate, impaired gut motility too (e.g. get rid of bili relatech chem) –> cause jaundice
What problems are associated with neonatal jaundice?
- may be a sign of underlying problem e.g. infection
- kernicterus: encepalopathy
What is kernicterus encephalopathy and how does it relate to neonatal jaundice?
- kernicterus encephalopathy is caused by the deposition of
- unconjugated bilirubin (e.g. not conjugated to glucuronic acid in hepatocytes yet) in the Basal ganglia and brainstem
- these have neurotoxic effects which can be
- transient or
- permanent
A jaundiced neonate presents with lethargy and poor feeding which type of kernicterus would this be?
mild type
A jaundiced neonate presents with irritability, seizures, increased muscle tone causing baby to arch their back (opisthotonos) and death.
What kernicterus type is this?
Severe type!
What are the long term (permanent) complications of neonatal jaundice?
- learning difficulties
- sensorineural hearing loss
- cerebral palsy
The presentation time of jaundice can indicate if its is pathological or not. What time frames are they?
- < 24 hours - ALWAYS PATHOLOGICAL
- 24h-14days = PHYSIOLOGICAL
- > 14d = PROLONGED SO RREFER
In a jaundiced neonate the urine is normal colour, but contains +++ urobilinogen
Stool: normal/ dark
Pruritus: no
LFTs: normal
Is the jaundice caused by conjugated or unconjugated bilirubin?
Unconjugated
in a jaundiced neonate the urine is dark, ++ conjugated bilirubin + bile salt
Stool: acholic (no bile)
Pruritus: yes
LFTs: ALP 10-12x increased
what type bilirubin is causing this jaundice?
Conjugated (serious liver disease)
- Rhesus haemolytic disease
- ABO haemolytic disease
- Hereditary spherocytosis
- G6PD deficiency
What type and presentation of neonatal jaundice do these conditions give?
they are jaundice caused by unconjugated bilirubin e.g. from breakdown of haemoblobin
What type and presentation of neonatal jaundice do these conditions give?
- Breast milk polycythaemia (most commonly)
- (Infection e.g. UTI)
- (Haemolytic disease)
jaundice occurs because of unconjugated bilirubin
these conditons occur betweek 24 hrs and 14d
they are physiological TF
(although infection and haemolysis are pathophysio)
What type and presentation of neonatal jaundice does sepsis give?
sepsis gives a conjugated bilirubin issue –> jaundice
(from dysfunction of hepatic cells etc & ~serious liver disease)
What type and presentation of neonatal jaundice do these conditions give?
- (Breast milk polycythaemia)
- Infection e.g. UTI
- Haemolytic disease
- Congenital hypothyroidism
These give unconjugated bilirubin rise
at >14days - meaning its prolonged & should refer
What type and presentation of neonatal jaundice do these conditions give?
- Biliary atresia
- Neonatal hepatitis syndrome
These are problems with conjugated bilirubin e.g. serious liver disease
they happen >14days (prolonged) - so REFER
NB: Biliary atresia (raised conjugated bilirubin, pale stool, dark urine)
What is the urine, stool, pruritus status and LFTs like for unconjugated bilirubin jaundice?
- normal urine
- +++ urobilinogen
- normal/dark stools
- no pruritus
- normal LFTs
What is the urine, stool, pruritus status and LFTs like for conjugated bilirubin jaundice?
- Dark urine
- ++conjugated bilirubin + bile salts
- acholic/white stool
- yes pruritus
- ALP 10x increased
60% of newborns get this type of jaundice. What type is it and why does it occur?
- physiological jaundice
- due to high Hb levels caused by:
- high concentration of hb at birth
- neonatal erythrocytes life span are only 70d whilst adults are 120d
- hepatic bilirubin metabolism is less efficient within 1st few days
normally disappears by 5w of age (but >14d is prolonged as a general rule so still refer?)
15% of breast fed babies will get this type of jaundice what is it?
breast milk jaundice
- continue breastfeeding
- (caused by low breastfeeding / slow start(?) as not enough breast milk slows a babys bowel movements which normally help secrete bilrubin buildup)
- jaundice will resolve after 3-4 wks
A neonate (who has not had any antenatal screening/management) is born & has anaemia, hydrops, hepatosplenomegaly & jaundice
what could cause this?
Rh incompatability!
now its rare due to antenatal screening and management
What does a positive coombs test mean?
NB: coombs test is also called the direct antiglobulin test (DAT)!
it demonstrates there is antibodies on erythrocytes
this diagnoses ABO incompatability
most ABO abs are IgM but sometimes IgG anti-haemolysin can be made in people with group O
–> IgG transfers trans-placentally (its the only one able to do that)
so –> to the foetus
TF if the foetus has group A or B blood = haemolysed erythrocytes
(group o-MG it attacks with both antibodies as has nothing on its surface)
What is G6PD?
How does G6PD deficiency cause naonatal jaundice (Onset w/i 24h of birth)?
- G6PD is an enzyme found in erythrocytes that PREVENTS oxidative damage
–>
- infection, broad beans and certain drugs e.g. aspririn, particular anti-malarials & anti-biotics TRIGGER acute haemolysis
What is sperocytosis?
Sperocytosis is a genetic condition (TF often a Fhx)
where a mutation in an erythrocyte skeletal protein makes it spheroidal in shape - increased haemolysis –> neonatal jaundice
What can cause unconjugated hyper-bilirubinaemia?
INFECTION –> unconjugated hyperbilirubinaemia
–> may develop due to
- poor fluid intake,
- reduced hepatic function,
- haemolysis and
- increase in enterohepatic circulation
(liver overwhelmed)
NB: enterohepatic circulation = the circulation of biliary acids, bilirubin, drugs or other substances from the liver to the bile, followed by entry into the small intestine, absorption by the enterocyte and transport back to the liver
A healthy baby ~3wks old is jaundiced, with yellow urine, pale stool and hepatosplenomegaly
maybe associated with cardiac abnormalities, situs invertus and polysplenia
What is the condition, pathophys and Rx?
-
Biliary atresia!
- is rare but serious
- there is biliary trree occlusion by angiopathy (BV disease) @ ~3 weeks old
- if you dont treat you can get advanced liver damage, cirrhosis
- w/i 1 year will need a transplant
- Rx: EARLY surgery –> KASAI procedure
- hepatoportoenterostomy
- (allows bile drainage by attaching small intestine directly to liver)
- hepatoportoenterostomy
if not diagnosed early rhen delayed treatment can cause liver failure & death
in jaundice what else may occur apart form yellowing of skin and sclera?
they may be drowsy
or have hepato or splenomegaly
–> if hepato/splenomegaly this suggests the jaundice is not physiological
The first investigation needed in a jaundiced neonate is if the high amount of bilirubin is unconjugated or conjugated. What are the tests to do if it is unconjugated?
- Bilirubin –>
- can TF see if unconj or conj:
- if unconj = screen for haemolytic disease, infection/sepsis & hypothyroid;
- Blood group
DAT (coombs test)
Full blood count
G6PD levels
The first investigation needed in a jaundiced neonate is if the high amount of bilirubin is unconjugated or conjugated. What are the tests to do if it is conjugated?
- if conj = screen for infection, metabolic or genetic causes
- e.g. B. atresia, neonatal hepatitis, sepsis
- Sepsis – Blood culture
- e.g. B. atresia, neonatal hepatitis, sepsis
-
USS bile ducts and gallbladder
- dilated gallbladder = choledocal cysts
- non-dilated gallbladder = complete a TBIDA radionucleide scan to see if patent biliary tree or not
- if not patent biliary tree = biliary atresia
- if patent –> liver biopsy
Why is it important to plot bilirubin measurement?
- You plot them bilirubin levels against age in hours
- this shows the threshold for treatment
- the Rx threshold is lower for preterms
What is the Rx for neonatal jaundice?
Phototherapy
- converts unconjugated bilirubin (e.g. in blood/hepatic sinusoid)–> harmless isomers
~Blood transfusion may be needed
If a specific cause is found treat it
- e.g. surgery for biliary atresia - Kasai procedure
