Cycled Phototherapy

Were they not delivered early, extremely premature infants would normally develop in darkness within the uterus for 3-4 more months longer before birth. Yet, the routine care of these infants has involved the use of uninterrupted (continuous) exposure to bright light during phototherapy (PT), a treatment method that neonatologists have assumed has no serious adverse effects on even the most immature of newborns.

Immaturity, thin translucent skin, and a multitude of other problems may make extremely premature infants highly vulnerable to the photo-oxidative injury, lipid peroxidation, DNA damage, reduced cerebral and mesenteric blood flow, or other serious potential hazards of uninterrupted exposure to PT that have now been identified. Such hazards were not recognized when continuous PT was widely incorporated into neonatal care, and the survival rate of extremely premature infants (<27 wks gestation or <750 g birth weight) was much lower than today.

PT rapidly photoisomerizes bilirubin in the subcutaneous tissues and vasculature, and six trials of cycled PT have demonstrated that use of cycled PT reduces the total hours of PT and results in minimal or no increase in peak TSB over that with continuous PT in term or moderately preterm infants. Recent findings from a pilot study (NCT01944696) support a PT regimen for this Cycled Phototherapy protocol.

Infants born at one of the Neonatal Research Network centers, ≤ 750 grams at birth and/or < 27 weeks gestation at birth by best OB estimate will be considered for this study.

Those who qualify will be randomized to either cycled PT or continuous PT. The cycled phototherapy begins with >15 min/h cycled PT regimen and increased to 30 min/h if the TSB is 8.0-9.9 and 60 min/h if the TSB is >10 mg/dL. Those randomized to continuous phototherapy will undergo continuous exposure,as that is commonly used in NRN centers.

The PT lamp position will be adjusted to meet the irradiance (µW/cm2/nm) goal of 22 at the umbilicus. The irradiance goal in both groups will be increased from 22 to 33 at a TSB of 10-13 and to 40 at a TSB >13.