Phototherapy for indirect hyperbilirubinemia

Severe indirect hyperbilirubinemia can cause encephalopathy and kernicterus, resulting in life-long neurosensory impairments. Phototherapy detoxifies bilirubin by converting it to a soluble non-toxic product which can be readily excreted.

Infants with pathophysiologic processes leading to rapid and excessive bilirubin production (for ex. hemolysis) and infants admitted for significantly elevated bilirubin levels (>17 mg/dl) should be treated with aggressive phototherapy, and may need an exchange transfusion if response is inadequate.

Since the precise level at which serum bilirubin causes injury is not known and probably varies with each individual infant, phototherapy is often used early in preterm infants with mild to moderate hyperbilirubinemia to prevent them from developing excessively high levels. At VUMC, a general guideline for routine use of phototherapy in the preterm infant in the first days of life is to consider administering phototherapy when Tbili > ¼ gestational age ("light level").

Phototherapy may be administered using overhead spotlights or a fiberoptic pad placed under the infant (a "biliblanket.") The efficacy of phototherapy depends on the surface area of the infant’s skin exposed to light. For small preterm infants, the spotlights and biliblanket are equally effective. For larger preterm and term infants, spotlights are more effective, presumably because they cover a larger surface area. Infants with hemolysis and/or excessively high bilirubin levels should receive intensive phototherapy consisting of at least 2 lights and a biliblanket to cover maximal surface area.

To expose maximal surface area, infants under phototherapy should be undressed. Infants receiving intensive phototherapy should be without diapers (although a "bikini" diaper or mask may be needed for excessive stooling.)

The eyes of all infants under phototherapy should be covered with eye shields. Eye shields should be removed at least every 4 hours for approximately 15 minutes while the eyes are cleansed by instilling normal saline in them to maintain moisture. Infants receiving routine phototherapy may have phototherapy interrupted and their eye shields removed for feeds and to interact with parents.

After starting phototherapy, infants should have a skin and/or bed temperature recorded hourly until stable. The term infant with exposed skin may or may not need an additional heat source to maintain body temperature under phototherapy. An open bed warmer or incubator should be used to regulate body temperature for a preterm or low birth weight infant.

Infants under phototherapy may be turned and positioned as needed. Skin rashes and frequent loose green stools are side-effects of phototherapy requiring meticulous skin care especially in the perineal region to prevent breakdown. When blood is drawn for a bilirubin level from an infant receiving phototherapy, the phototherapy lights should be temporarily turned off and the blood collected in a darkened tube to avoid a falsely low reading due to bilirubin photodegradation in the tube.

Click here for a handy tool for Phototherapy Guidelines: BiliTool

References:

Mills JF, Tudehope D. Fibreoptic phototherapy for neonatal jaundice. http://www.nichd.nih.gov/cochrane/Mills/Review.htm