Phototherapy in the management of neonatal hyperbilirubinemia: efficacy with light sources emitting more than 500 nanometers.

The clinical action of green fluorescent lamps, properly filtered to remove wavelengths of less than 500 nm, was investigated in a group of 23 newborns with different initial serum bilirubin concentrations. The serum bilirubin levels were measured at 6, 12, 24, and 48 hours after the beginning of phototherapy. These results are compared with those obtained, under the same experimental conditions, in a group exposed to commercial green lamps. Similar bilirubin decline rates were observed in the two experiments. In general, these data confirm the satisfactory clinical efficacy of the green light in phototherapy and prove, in particular, that the blue component present in the emission spectrum of the commercial green lamps has a negligible effect on the bilirubin degradation process.