Jaundice Flashcards
What defines prolonged jaundice after birth
> 14 days if term
21 days if preterm
What are the causes of neonatal jaundice in the first 2 weeks of life
<24h: ALWAYS PATHOLOGICAL
Haemolytic anaemia (ABO/Rhesus incompatibility, G6PD deficiency, spherocytosis, pyruvate kinase deficiency)
Infection
Inborn error of metabolism
liver disease
> 24h - 2 weeks: usually physiological
Physiological (high conc. RBCs with short lifespan)
Breast milk jaundice
Infection
Haemolysis, polycythaemia
Bruising
Congenital hypothyroidism
Gilbert’s syndrome
Crigler-Najjar syndrome (glucoronyl transferase deficient or absent)
What are the causes of neonatal jaundice after the first 2 weeks of life
Unconjugated
Haemolysis: Haemolytic anaemia (ABO/Rhesus incompatibility, G6PD deficiency, spherocytosis)
Hepatic
Infection
Pyloric stenosis
Conjugated:
Hepatic: hepatitis, cystic fibrosis, cirrhosis
Obstructive: biliary atresia, bile duct obstruction, hepatitis, bile duct stones, cholecystitis, choledochal cyst, cholangitis
What are the causes of jaundice in older children
Pre-hepatic:
Malaria
SCD
G6PD deficiency
Haemolytic anaemia
Hepatic:
Infection e.g. CMV, HSV, hepatitis
Drugs
Toxins
Autoimmune hepatitis
Wilson’s disease
Post-hepatic:
Bild duct stones
Cholecystitis, choledochal cyst
Cholangitis
Describe the production and metabolism of bilirubin
- Bilirubin is produced as a result of haem breakdown (unconjugated, insoluble)
- The unconjugated bilirubin is then metabolised by liver cells to a soluble conjugated form
- This is excreted via the hepatic and bile ducts into the duodenum
- Bilirubin and bile salts in the bowel aid in absorption of fats and fat-soluble vitamins
- 1/2 is reabsorbed from the bowel as urobilinogen (enterohepatic circulation)
- Excretion in the urine or re-metabolised in the liver.
Describe ABO incompatibility leading to jaundice
Most ABO Abs are IgM and do not cross the placenta, but some group O women have an IgG anti-A-Haemolysin in their blood that can cross the placenta and haemolyse the red cells of a group A infant
Group B infants can also be affected by anti-B haemolysins
Presents with: moderate jaundice (peak 12-72h), Hb normal/slightly reduced, no hepatosplenomegaly
Coomb’s test positive
Describe G6PD deficiency causing neonatal jaundice
Seen in those from the Mediterranean, Middle-East and Far East or in Africa
Mainly affects male infants, but some females develop significant jaundice
Parents of affected infants should be given a list of drugs to be avoided as they may precipitate haemolysis
Describe Rh haemolytic disease causing neonatal jaundice
Now rare due to screening and anti-D Abs given to those at risk
Otherwise: anaemia, hydrops, hepatosplenomegaly, severe jaundice
Describe physiological jaundice
Mild or moderate jaundice
No underlying cause
Diagnosis of exclusion
Describe breast milk jaundice
More prolonged and common
Unconjugated bilirubin
Increased entero-hepatic circulation of bilirubin
Benign, may last up to 12 weeks
What should you look for on examination for neonatal jaundice
Height and weight: ? Failure to thrive
Skin:
- Visible Jaundice
- Blanch the skin with a finger to see it better
- Starts on the face then spreads to the trunk and limbs
- Check with transcutaneous bilirubin meter or blood sample
- Excoriations due to pruritus
- Chronic liver disease: Spider naevi, clubbing, ascites
- Evidence of bruising e.g. cephalhaematoma (exacerbates jaundice)
Abdominal
- Hepatomegaly
- Hard liver: cirrhosis
- Splenomegaly: haemolysis, cirrhosis
What investigations should be done for jaundice in children
- Transcutaneous bilirubin meter or serum bilirubin within 6 hours of presentation
- <24 hours/<25w → serum BR
- 24 hours to 2 weeks/>35w → transcutaneous BR
- 2 weeks → split serum BR
- If the result is >250 μmol/L, check the result by measuring serum bilirubin
Bedside: TC bilirubin meter
Bloods: FBC (haemolysis, sepsis), Blood film, LFTs, ALP, hepatitis serology, DAT, blood culture, TFTs, osmotic fragility testing, G6PD levels, blood group of mother and baby
Other: consider CSF in infection
What is the management for neonatal jaundice
- Clinical assessment
- Measure bilirubin (transcutaneous, serum) → plot on a jaundice chart
→reaches threshold: - Phototherapy (uBR → harmless water-soluble pigment excreted into the urine)
- Repeat serum bilirubin ever 6 hours → stable/falling → every 6-12h
- Can be stopped once the serum bilirubin level is > 50 mmol/L below the threshold for treatment
- Check for rebound hyperbilirubinaemia 12-18h after stopping - Exchange transfusion (when bilirubin levels exceed the treatment line) + folic acid (2x infant’s blood volume is exchanged)
± IVIG (for those with haemolytic disease)
Serum bilirubin should be measured EVERY 6 hours until it drops below the treatment threshold or becomes stable/ falling
What features necessitate urgent admission/referral for jaundice
Emergency: Jaundice + encephalopathy signs e.g. atypical sleepiness, poor feeding, vomiting, hypotonia, hypertonia
Urgent:
- <24h since birth or > 7 days of age
- Unwell e.g. lethargy, fever, vomiting
- Gestational age <35 weeks
- Prolonged jaundice
- Feeding problems/concerns about weight
- Pale stools and dark urine
What are the complications of jaundice in neonates
Neonatal jaundice
Kernicterus: Deposition of unconjugated bilirubin in the basal ganglia → lethargy, irritability, poor suck, abnormal muscle tone and posture (opisthotonus), high-pitched cry, apnoea, seizures, and coma
→ choreoathetoid cerebral palsy, learning difficulties, sensorineural deafness
