Ency. home > SpecialTopic > B > Bili lights

Bili lights   

Overview

Alternative names:

Phototherapy

Information

Definition:
A therapeutic procedure performed on newborn or preterm infants who have elevated levels of bilirubin, to reduce the bilirubin level and treat hyperbilirubinemia. Specific wavelenghts of light from special fluorescent lamps penetrate the infant's skin where the light breaks down bilirubin into nontoxic water-soluble components that are then excreted in the urine.

Background:
Bilirubin in the blood is normally converted to a water soluble form (conjugated bilirubin) in the liver. Conjugated bilirubin can be filtered by the kidneys and excreted in the urine.

In a newborn infant the still immature liver can only convert a limited amount of bilirubin into its conjugated form, so if blood levels of bilirubin become too high, the bilirubin begins to dissolve in the body tissues, producing the characteristic yellow eyes and yellow skin of jaundice. Bilirubin also has an affinity for brain tissue where it can accumulate and cause permanent brain damage if the levels become too high.

Phototherapy treatment:
The treatment for newborn jaundice depends on three factors: the birth weight, concentration of bilirubin in the blood, and the newborn's age in hours. In severe cases of hyperbilirubinemia where the newborn has a low birth weight, is less than 24 hours old, and has a high bilirubin level, an exchange transfusion is preferred over phototherapy. With very high bilirubin concentrations, regardless of the age and weight, an exchange transfusion is the best option. (In rare cases blood incompatibility between the mother and fetus causes antibodies to form in the mother, and these antibodies are transferred through the placenta to the baby, which causes destruction of the baby's red cells (see Rh disease). An exchange transfusion is required to remove these destructive antibodies from the baby's blood - as well as to reduce the high circulating levels of bilirubin.)


Phototherapy involves the exposure of bare skin to intense fluorescent light. Specific wavelengths of the light interact with the bilirubin breaking it into several non-toxic water soluble components that can be excreted in the urine and stool. For phototherapy treatment the newborn is placed, without clothes or in a small diaper, under the fluorescent lights with the eyes covered to protect them from the bright light. Body temperature, vital signs, duration of treatment, positioning of the bulbs, and the newborns responses are carefully noted. The child is turned frequently to maximize the effects of therapy. If a baby is stable, phototherapy can be used at home along with the daily visits of a nurse who can obtain a sample of blood for testing. Dehydration may result from this therapy so an increase in fluid intake is necessary. Bilirubin levels are monitored and when the levels have declined sufficiently and remain down the infant is removed from beneath the lights.

Depending on the cause of jaundice full recovery is usually expected.

Ency. home > SpecialTopic > B > Bili lights

---

[an error occurred while processing this directive]