The Bhutani nomogram allows physicians to risk stratify newborns to determine which of them is at greatest risk of developing clinically significant hyperbilirubinemia.

Feeding a newborn with hyperbilirubinemia is an important part of treatment as it allows for elimination of bilirubin. Bilirubin is excreted through stool and feeding also reduces the rate at which bilirubin is reabsorbed through the intestinal wall and recycled into the circulation.

Phototherapy is typically required in infants that overproduce bilirubin secondary to causes such as G6PD deficiency, blood group incompatibility or other causes of hemolysis. About 5 to 6 percent of babies across the United States will require phototherapy and most of them will be late preterm babies as their conjugation system is immature and does not allow them to effectively clear the bilirubin.

Acute bilirubin encephalopathy is used to describe the acute manifestations of bilirubin toxicity seen in the first weeks after birth. There are few studies that look at the incidence of acute bilirubin encephalopathy but, according to Dr. Bhutani, about 1 in 700 infants >35 weeks gestation can develop serum bilirubin values of >25 mg per 100 ml and approximately 1 in 10 000 have levels of >30 mg per 100 ml.

One of the few indications for exchange transfusion is if the baby has neurological signs of acute bilirubin encephalopathy.

In the early phase of acute bilirubin encephalopathy, infants become lethargic and hypotonic and suck poorly. The intermediate phase is characterized by irritability and hypertonia; infants may have a high-pitched cry. The hypertonia is manifested by backward arching of the neck (retrocollis) and trunk (opisthotonos). In the advanced phase, the infant may have a shrill cry, no feeding, and coma.

After phototherapy is initiated, a repeat bilirubin level should be obtained at the two hour mark to ensure that the value is coming down. If the bilirubin has decreased, levels can be checked every 4 to 6 hours and even up to every 12 hours if the value is far from the exchange transfusion threshold.

In infants in which phototherapy was initiated prophylactically, phototherapy does not need to be administered continuously but rather breaks for feeding and holding should be permitted.