Phototherapy in the newborn: what’s new?

Abstract

When exposed to light, bilirubin undergoes photoisomerization which are water-soluble and can be excreted in bile and urine. Photoisomerization starts as soon as the lights turned on, and risk of bilirubin encephalopathy is lower in infants who receive phototherapy even in the same serum bilirubin levels. Blue light is absorbed most readily if bilirubin is in a tube, but skin penetration and albumin binding shift of the most effective light to blue-green region. However, there is no consensus on the most effective wavelength for phototherapy. The light sources used in conventional phototherapy are fluorescent bulbs, halogen lamps or light-emitting diodes (LED) with equally effective in reducing serum bilirubin levels. Fiberoptic devices are less effective. Despite higher irradiance in double or triple phototherapy, there is no superiority in clinical settings. Hyperthermia and skin rashes are higher when used super (high-intensity) LED devices. Watery loose stools may cause dehydration in preterm infants. Riboflavin loss and lipid peroxidation are prevented with using dark tubing or covering the line with aluminum foil. The consequences of light penetration into deep brain in newborn infants because of open wide fontanel and thin skull is unknown. Non-ocular light exposure and suppressed melatonin secretion may affect autonomic and behavioral disturbances. Phototherapy-induced hypocalcemia may be prevented by covering the head. Phototherapy does not effect ductal patency or reopening, its effect on the incidence of retinopathy of prematurity have yielded conflicting results. Neonatal phototherapy increases the risk of asthma and allergic disorders in older age groups. Aggressive (low-threshold) phototherapy increase mortality risk in small preterm infants less than 750 g at birth, which may be related to the reduced bilirubin with its antioxidant effects. In conclusion, phototherapy is not a treatment without side effects and overtreatment should be reevaluated in small preterm infants.

Proceedings of the 11^th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy) · October 26^th-31^st, 2015 · From the womb to the adult
Guest Editors: Vassilios Fanos (Cagliari, Italy), Michele Mussap (Genoa, Italy), Antonio Del Vecchio (Bari, Italy), Bo Sun (Shanghai, China), Dorret I. Boomsma (Amsterdam, the Netherlands), Gavino Faa (Cagliari, Italy), Antonio Giordano (Philadelphia, USA)