Jaundice in the neonatal period Flashcards
Causes of unconjugated hyperbilirubinemia
1) Hemolytic
a) Intrinsic
- Membrane: spherocytosis, elliptocytsis
- Enzyme:G6PD, PK deficiency
- Hb: thalassemia
b) Extrinsic
- ABO, Rh incompatibility
- Splenomegaly
- Sepsis
- AV malformation
2) Non-hemolytic
- Hematoma
- Polycythemia
- Sepsis
- Hypothyroidism
- Gilbert
- Crigler-Najjar
3) Physiologic
Causes of conjugated hyperbilirubinemia
1) Hepatic
a) Infectious- Hep A, B, C, Sepsis, TORCH
b) Metabolic- Galactosemia, tyrosinemia, A1AT, Hypothyroid, CF
c) Drugs
d) TPN
e) Idiopathic neonatal hepatitis
2) Post hepatic
- Biliary atresia
- Choledochal cyst
Important history
Baby unwell- sepsis? bowel obstruction? Dehydration, poor weight gain- can exacerbate serology, viral FHx of hemolysis Dark urine, pale stools Plethora Hepatosplenomegaly->metabolic, viral
Investigations in unwell child/febrile
Septic screen FBE/CRP/BC UEC/LFT/VBG/Glucose IV antibiotics Bilirubin Blood film/Reticulocytes Blood group/Coombs
Investigations in well, afebrile
FBE
Bilirubin
Blood film/Reticulocytes
Blood group/Coombs
Investigations if conjugated bilirubin >15%
LFTs Clotting TFTs Septic screen Viral serology A1AT levels Abdominal USS DW gastroenterology
Investigations when evidence of hemolysis
DW haematologist
Investigations when total in treatable range
NNU consultations Urine MCS/reducible UEC G6PD TFTs
Investigations when prolonged, and what is considered prolonged w/o an obvious cause
Prolonged is >2 weeks in full term and >3 weeks in preterm DW paediatric senior Urine MCS/reducing substrates TFTs G6PD Arrange follow up
What are reducing substances
Galactose
Fructose
Glucose
Glycosuria -ve, but + urine for reducing substances, management
Further testing required
Remove lactose immediately from diet, pending results of further investigations
Discharge instructions for unconjugated hyperbilirubinemia
Sunlight is not treatment
Early F/U with GP
Ensure adequate oral intakes, especially
Phototherapy- hydration, monitoring, rechecking bilirubin
++Attention to fluid intake and hydration
Correct hydration over at least 24 hours
Check bilirubin after 6 hours starting therapy
What level of bilirubin rise should warrant call to NNU
If rate of rise >10micromol/L/hour
Final option for treatment if supportive and phototherapy no longer appropriate
Exchange transfusion
Important examination
Extent of the jaundice Congenital viral infection->petechiae, anemia, hepatosplenomegaly Dehydration Well Evidence of infection Examine the stool
Why is checking clotting and vitamin K levels important
Prolonged jaundice can +risk of bleeding disorders associated with vitamin K deficiency
Wavelength of phototherapy
450nm
Commonest cause of jaundice in an older child
Hepatitis A
Other causes of jaundice in older children
Chronic hemolysis->spherocytosis, G6PD Autoimmune chronic hepatitis Reyes syndrome Paracetamol overdose Wilson's Gilberts Cigglar-Najar
When does physiological jaundice occur, and when does it resolve
Occurs on day 2-3, usually resolves in 7 days
Pathophysiology of physiological jaundice (3)
1) +Hct and reduced RBC lifespan
2) Immature conjugating system
3) Increased enterohepatic circulation
Risk factors for jaundice: maternal, perinatal, neonatal
Maternal:
Ethnic group
Complications->diabetes
Rh/ABO incompatibility
Perinatal:
Birth trauma
Prematurity
Neonatal factors: Difficulty establishing breathing Infection Genetics Polycythemia Drugs
Causes of jaundice
Causes of jaundice 24-72
24-72 h Physiologic, polycythemia Dehydration (breastfeeding jaundice) Hemolysis G6PD deficiency Pyruvate kinase deficiency Spherocytosis Bruising, hemorrhage, hematoma Sepsis/congenital infection
Causes of jaundice 72-96
72-96 h Physiologic ± breastfeeding Sepsis Prolonged Breast milk jaundice
Causes of prolonged
Breast milk jaundice Prolonged physiologic jaundice in preterm Hypothyroidism Neonatal hepatitis Conjugation dysfunction e.g. Gilbert syndrome, Crigler-Najjar syndrome Inborn errors of metabolism e.g. galactosemia Biliary tract obstruction e.g. biliary atresia
Differentiate breastfeeding jaundice vs breast milk jaundice
Breastfeeding jaundice if when reduced breast milk production->dehydration->exagerated physiologic jaundice
Breast milk jaundice: glucuronyl transferase inhibitor found in breast milK, onset day 7, persists for several weeks and resolves by 6 weeks. If not reason to cease breastfeeding
Red flags for pathalogical
1-2 weeks of age
Hemolytic work up
CBC Reticulocyte Blood group Blood smear Coombs test Bilirubin
How does phototherapy work
Insoluble unconjugated bilirubin is converted to excretable form via photoisomerisation
Can you perform phototherapy in conjugated hyperbilirubinemia, why
No
Results in bronzed baby
Etiology of kernicterus
Unconjugated bilirubin levels ++ than binding capacity of albumin->deposit in brain stem and basal ganglia
What level of bilirubin= risk of kernicterus
When levels >340umol/L
When can kernicterus occur at lower levels than
sepsis, meningitis, hemolysis, hypoxia, acidosis,
hypothermia, hypoglycemia and prematurity
Clinical presentations: early (4), mid (6), late stage (6)
Early: hypotonia, lethargic, poor feeding, emesis
Mid: hypertonic, high pitched cry, opisthotonic posturing (back archign), bulging fontanelles, seizures and pulmonary hemorrhage.
Late (beyond a year): hypotonia, EPS (choreoathetoid cerebral palsy), gaze palsy, mitral regurgitation, sensorineural hearing loss.
Long term complications of kernicterus
Sensorineural deafness
Choreoathetoid cerebral palsy
Gaze palsy
Mental retardation
What is biliary atresia and how does it present
Atresia of extrahepatic bile ducts->cholestasis, +conjugated bilirubin Dark urine, pale stool Jaundice persisting for >2 weeks Abdominal distension hepatomegaly
Diagnosis of biliary atresia- investigations
Conjugated hyperbilirubinemia, abdominal USS
HIDA san
Liver biopsy
Treatment of biliary atresia
- surgical drainage procedure
* hepatoportoenterostomy (Kasai procedure; most successful if
