Newborn Phototherapy Irradiance Levels With and Without Commercial Covers

In phototherapy for neonatal hyperbilirubinemia, the use of covers placed between the newborn and the phototherapy source is variable. Guidelines often recommend a cover for the phototherapy blanket pad. Because covers could affect illumination levels, we assessed phototherapy irradiance levels from an overhead phototherapy system and a phototherapy blanket, with and without commercial covers.

In this nonclinical study, the overhead phototherapy system used calibrated radiometer measurements from 420 to 500 nm at 2 distances below the light source; the phototherapy blanket used measurements from 400 to 520 nm. We measured irradiance in 4 different variations using 2 types of covers (a mesh swaddle and a phototherapy blanket pad).

For the overhead system, at 30.5 cm below the light source and with a mesh swaddle covering the meter, the irradiance was 29.5 μW/cm2/nm, which was 14% lower than the value without covering (34.4 μW/cm2/nm). The mean irradiance at 15 cm from the light source with the mesh covering the meter (38.5 μW/cm2/nm) was 15% lower than without a cover (45.4 μW/cm2/nm). The irradiance under the zipper of the mesh swaddle was substantially lower at either distance. For the phototherapy blanket, the irradiance measured in all the posterior covering variations ranged from 61.1 (nest plus swaddle) to 98.5 μW/cm2/nm (no covering).

Clinicians should be aware that commercial phototherapy coverings affect irradiance; however, optimal irradiance can be achieved and may even exceed current American Academy of Pediatrics (AAP) recommendations of 25 to 35 μW/cm2/nm.