Important factors in the efficacy of phototherapy Important factors in the efficacy of phototherapy. The absorbance spectrum of bilirubin bound to human serum albumin (white line) is shown superimposed on the spectrum of visible light. Clearly, blue light is most effective for phototherapy, but because the transmittance of skin increases with increasing wavelength, the best wavelengths to use are probably in the range of 460–490 nm. Term and near-term infants should be treated in a bassinet, not an incubator, to allow the light source to be brought to within 10–15 cm of the infant (except when halogen or tungsten lights are used), increasing irradiance and efficacy. For intensive phototherapy, an auxiliary light source (light-emitting diode [LED] mattress, LED/fiber-optic pad, or special blue fluorescent tubes) can be placed below the infant or bassinet. If the infant is in an incubator, the light rays should be perpendicular to the surface of the incubator in order to minimize loss of efficacy due to reflectance. (Redrawn from Maisels MJ, McDonagh AF. Phototherapy for neonatal jaundice. N Engl J Med. 2008;358:920–928, with permission.) Source: Chapter 10. Phototherapy and Other Treatments, Care of the Jaundiced Neonate Citation: Stevenson DK, Maisels M, Watchko JF. Care of the Jaundiced Neonate; 2012 Available at: https://accesspediatrics.mhmedical.com/DownloadImage.aspx?image=/data/books/stev1/stev1_c010f005.png&sec=41542487&BookID=528&ChapterSecID=41538458&imagename= Accessed: November 16, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved