(4) Newborn Phototherapy Irradiance Measurements With and Without Commercial Shields

Background: Six percent of babies will require phototherapy as a newborn to prevent bilirubin induced neurotoxicity. Variations of intensive phototherapy have appeared because of different shielding that are in the market. For intensive phototherapy, irradiance should be no less than30 (µW/cm 2 /nm).

Objectives: To measure irradiance in the setting of the following variations:
1. Overhead phototherapy light system and blanket phototherapy no shielding.
2. Phototherapy with a 360-degree jumpsuit mesh fabric outfit (Woombie).
3. Phototherapy blanket with the cover but no shielding of overhead phototherapy (Nest).
4. Phototherapy blanket with the cover and the Woombie but no shielding of overhead phototherapy (Nest and Woombie).

Design/Methods: Using calibrated radiometer measurements for 420 to 500 nm, where an ideal control would be 35 ± 3.5 μW/cm2/nm 30.5 cm were made with a Neoblue ™ Natus Model at 30.5 cm, then at 15 cm, below the phototherapy sensor of the radiometer with and without a 360-degree swaddle made of mesh fabric that has a double zipper. Ten measurements anterior to side of zipper of the Woombie and five measurements under the zipper.

Using Center row spots recommended by the manufacturer (General Electric) ten measurements made and averaged using a calibrated Omeda BiliBlanket II with and without a blanker pad cover for 400 to 520 nm (Bilisoft Nest), and ten measurements with and without the irradiance sensor covered by the mesh of the Woombie.

Results: 1. Irradiance measured (µW/cm 2 /nm).: At 30.5 cm overhead with a bare chest 34.4, and at 15 cm 45.4
2. Irradiance measured at 30.5 cm with the Woombie 8.7 under the zipper, and anterior to the side of the zipper. At 15 cm, 11.3 under the zipper, and anterior to the side of the zipper 38.5.
3. Irradiance measured at the phototherapy blanket which would typically go below the baby: No cover 104.3 +/- 0.9, blanket covered by the Woombie 96.3+/- 0.35, and with the phototherapy blanket covered with the manufacturer recommended is nest cover 70.8 +/- 0.5.
4. Irradiance measured at the phototherapy blanket covered and Woombie together the average irradiance is 61.1 +/- 1.2 µW/cm 2 /nm.

Conclusion: Any shielding, overhead or under the baby, decreases phototherapy irradiance. Lower irradiance can be expected to result into less clinical efficacy unless the shielding has some independent benefit which compensates for the decreased irradiance. Further study to establish if shielding gives any clinical benefits is warranted.