Maintenance of Dose-Dependent Bilirubin Reduction with Ultra-High-Irradiance Phototherapy up to 148 μW/cm2/nm in Severe Neonatal Jaundice

Background/Objectives: Phototherapy is an effective first-line treatment for neonatal jaundice. Previous studies have demonstrated a linear dose-dependent relationship between irradiance and bilirubin reduction during intensive phototherapy up to approximately 55 μW/cm2/nm, although others have suggested that the therapeutic effect plateaus with higher irradiance. However, the efficacy and safety of treatment at these irradiance levels remain unclear. By focusing on newborns with severe jaundice close to the exchange transfusion threshold, we aimed to examine whether the dose-dependent association between phototherapy irradiance and bilirubin reduction is maintained at irradiance levels above 55 μW/cm2/nm.