Dose-response Relationship of Phototherapy for Hyperbilirubinaemia Using Diodes: is There a "Saturation Point"

Dose-response Relationship of Phototherapy for Hyperbilirubinaemia Using Diodes: is There a "Saturation Point"?

Background: Using light emitting diodes (LED's) during conventional phototherapy it is possible to reduce the distance from light source to infant, thereby increasing light irradiance.

Objective: To examine the relation between light irradiance and the rate of decrease in total serum bilirubin concentration (TsB) and to see if the investigators can identify a "saturation point", i.e. an irradiation level above which there is no further decrease in TsB.

Design: Prospective randomised study. Setting: Neonatal Intensive Care Unit, Pediatric Department, Aalborg Hospital, Aarhus University Hospital, Denmark.

Material and method: 151 infants with gestational age ≥ 33 weeks and uncomplicated hyperbilirubinaemia are randomised to one of 4 different distances from phototherapy device to mattress (20, 29, 38 and 47 cm). TsB is measured before and after 24 hours of phototherapy and irradiance every 8th hour. Main outcome measure is 24 hours decrease of TsB expressed in percent (∆ TsB0-24 (%)).

Inclusion Criteria:

• Gestational age ≥ 33 weeks
• Uncomplicated neonatal hyperbilirubinemia

Exclusion Criteria:

• < 33 weeks
• infants in incubators