Predict, Prevent and Manage Severe Hyperbilirubinemia in Term and Late Preterm Newborns

- Definitions

Acute bilirubin encephalopathy (ABE): A clinical syndrome in the presence of severe hyperbilirubinemia that consists of decreased feeding, lethargy, variable abnormal tone (hypotonia and/or hypertonia), high-pitched cry, retrocollis and opisthotonus, setting sun sign, fever, apnea, seizures, and death. ^{(17, 18)}

Chronic bilirubin encephalopathy (CBE): A clinical tetrad that occurs after the history of severe hyperbilirubinemia consisting of:

(1) A movement disorder consisting of not only athetosis and dystonia, but may also include spasticity and hypotonia.

(2) Auditory dysfunction consisting of sensory neural hearing loss or auditory dys-synchrony.

(3) Oculomotor impairments especially impairment of up-gaze, but also lateral gaze impairments including strabismus.

(4) Dental enamel hypoplasia of the deciduous teeth. ⁽¹⁹⁾

Kernicterus: The pathological finding of deep-yellow staining of neurons and neuronal necrosis of the basal ganglia and brainstem nuclei clinically associated with chronic bilirubin encephalopathy. ^(17,19)

Escalation of care: The intensive care that some infants with elevated or rapid increasing bilirubin concentration require to prevent the need for an exchange  and possibly prevent kernicterus. ⁽⁶⁾

Critical or, Extreme hyperbilirubinemia: A TSB concentration greater than 25 mg/dL during the first 28 days of life. ^(18,19)

Rebound Hyperbilirubinemia: Is defined as a TSB concentration that reaches the phototherapy threshold for the infant’s age within 72-96 hours of discontinuing phototherapy. ^(6,20)

Prolonged unconjugated jaundice: Infants 7 days or older with a persistently elevated TSB within 2 mg/dL of the phototherapy threshold may have prolonged indirect hyperbilirubinemia, which can be confirmed by measuring serum direct-reacting or conjugated bilirubin (i.e., a fractionated bilirubin measure) in addition to total bilirubin. ⁽⁶⁾

Intensive phototherapy: Requires a narrow spectrum LED blue light with an irradiance of at least 30 mW/cm2 per nm at a wavelength around 475 nm. ⁽⁶⁾