Treating acute bilirubin encephalopathy--before it's too late

A late-night telephone call from a parent of a recently discharged newborn reporting that the baby has, or may have, jaundice heralds a potential medical emergency-especially when jaundice is coupled with concerns about poor feeding, excessive sleepiness, irritability, or lethargy. This constellation of complaints requires detailed questioning about specific signs and symptoms, a review of the birthing and postnatal history and predischarge data, and, possibly, an emergency neurologic evaluation of muscle tone, alertness, and cry pattern for evidence of bilirubin-induced neurologic dysfunction (BIND).

Although the clinical signs described by the parent sound vague, and may simply reflect a new parent's anxiety or inexperience, they also could be early, nonspecific-but nevertheless sentinel-signs of acute bilirubin encephalopathy (ABE). ABE refers to the acute, and often progressive, manifestations of bilirubin toxicity that are seen in the first weeks after birth. When unmonitored or untreated, they may progress rapidly to advanced manifestations such as opisthotonus and seizures. If intervention to reduce the bilirubin load rapidly is neither timely nor efficient, chronic, permanent clinical sequelae of bilirubin toxicity-referred to as kernicterus-result and become increasingly apparent during infancy.

Newborn jaundice generally has a reassuringly benign outcome. It is kernicterus following an acute, brief, preventable exposure to extreme hyperbilirubinemia that can have lifelong deleterious effects. This article discusses the clinical signs, symptoms, and known causes of kernicterus and presents a systems-based strategy for preventing it. The strategy is based on predischarge screening and a bilirubin measurement plotted on the hour-specific bilirubin nomogram to identify newborns at risk of severe hyperbilirubinemia and to target follow-up to prevent irreversible damage.

The damage ranges from minimal to severe with signs of ABE: kernicteric sequelae, isolated auditory neuropathy (a form of sensorineural hearing loss), extrapyramidal movement disorders, or a combination of neuromotor, sensorineural hearing disability, and visual disability. Some experts believe that BIND may have milder, subtler neurologic manifestations, but this theory is unproven.^6-11