Guidelines for detection, management and prevention of hyperbilirubinemia in term and late preterm newborn infants Flashcards
What is kernicterus?
Pathological finding of deep yellow staining of neurons and neuronal necrosis of the basal ganglia and brainstem nuclei
What is acute bilirubin encephalopathy?
A clinical syndrome, in the presence of severe hyperbilirubinemia, of lethargy, hypotonia, and poor suck, which may progress to hypertonia (with opisthotonos and retrocollis) with a high-pitched cry and fever, and eventually to seizures and coma
What is chronic bilirubin encephalopathy?
The clinical sequelae of acute encephalopathy with athetoid cerebral palsy with or without seizures, developmental delay, hearing deficit, oculomotor disturbances, dental dysplasia, and mental deficiency
What is severe hyperbilirubinemia?
A total serum bilirubin concentration greater than 340umol/L at any time during the first 28 days of life
What is critical hyperbilirubinemia?
A TSB concentration greater than 425umol/L during the first 28 days of life
What percentage of term newborns develop jaundice?
60%
What percentage of term newborns reach TSB concentration > 340umol/L?
2%
What increases the risk of acute encephalopathy in the presence of severe hyperbilirubinemia?
- Dehydration
- Hyperosmolarity
- Respiratory distress
- Hydrops
- Prematurity
- Acidosis
- Hypoalbuminemia
- Hypoxia
- Seizures
What is the incidence of acute bilirubin encephalopathy?
1 in 10 000 live births
What is the incidence of chronic encephalopathy?
1 in 100 000 live births
What is the incidence of critical hyperbilirubinemia or requiring exchange transfusion?
4 in 10 000 live births
What are risk factors for the development of severe hyperbilirubinemia?
- Visible jaundice at younger than 24h
- Visible jaundice before discharge at any age
- Shorter gestation (<38 weeks)
- Previous sibling with severe hyperbilirubinemia (OR 4.8)
- Visible bruising (OR 2.6)
- Cephalhematoma (OR 3.6)
- Male sex (OR 1.3 to 1.7)
- Maternal age >25y of age (OR 2.6)
- Asian or European background (OR 5.2 and 1.2, respectively)
- Dehydration
- Exclusive and partial breastfeeding
What is the best available method for predicting severe hyperbilirubinemia?
Timed TSB measurement (18h-72h) analyzed in the context of the infant’s GA
For example to have a >10% risk of developing severe hyperbilirubinemia the infant <38wks GA must have a TSB >75th %ile and the infant 39-40wks GA must have a TSB >95th %ile
What is the predictive power of umbilical cord blood TSB?
TSB >30umol/L in cord blood correlated with peak TSB >300umol/L
PPV 4.8% term infant, 10.9% late preterm
Very poor specificity
What is the predictive power of universal hemoglobin assessment?
Routine umbilical cord blood hemoglobin or hematocrit does not aide in the prediction of severe hyperbilirubinemia
What is the OR for severe hyperbilirubinemia in babies whose mothers are blood group O?
2.9
When is it reasonable to perform a DAT?
In clinically jaundiced infants of mothers who are group O and in infants with an elevated risk of needing therapy
How is G6PD inherited?
X-linked inheritance
Why should females be tested for G6PD deficiency?
Female heterozygotes can have >50% of RBC deficient in the enzyme due to random inactivation of the X chromosome
Who should be tested for G6PD deficiency?
- Infants whose ethnic group (e.g. Mediterranean, Middle Easter, African, SE Asian) increases risk
- Infants whose family history suggests increased risk
- Consider in all infants with severe hyperbilirubinemia
What is the predictive value of end-tidal CO?
Exhaled CO increased during hemolysis
Prediction of severe hyperbilirubinemia is not improved by measurement of ETCO2
What are the recommendations re: prediction of severe hyperbilirubinemia?
- All mothers should be tested for ABO and Rh (D) blood types and screened for red cell antibodies during pregnancy
- If mother was not tested, cord blood from the infant should be sent for evaluation of the blood group and a DAT
- Blood group evaluation and a DAT should be performed in infants with early jaundice of mothers of blood group O
- Selected at-risk infants (Mediterranean, Middle Eastern, African, or SE Asian origin) should be screened for G6PD deficiency
- A test for G6PD deficiency should be considered in all infants with severe hyperbilirubinemia
At what concentration is jaundice not evident on clinical examination?
<68umol/L
When does the peak TSB concentration usually occur?
3-5 DOL