ACTION SPECTRUM FOR NEONATAL JAUNDICE PHOTOTHERAPY: PREDICTION AND CLINICAL EVIDENCE

摘要

The in vivo action spectrum for the phototherapy of infant hyperbilirubinemia was predicted on the basis of (ⅰ) in vitro bilirubin photochemistry, (ⅱ) excretion rates of bilirubin photoproducts and (ⅲ) the optical properties of skin. Formation and excretion of the structural bilirubin photoisomers, lumirubin, is considered the major mechanism for the light-induced reduction of serum bilirubin in babies under phototherapy. Consequently, the action spectrum for bilirubin disappearing should match that for the bilirubin → lumirubin photoreaction. This was calculated to be peaked at 490 nm, with a band width of about 50 nm. Clinical validation of this result was obtained by using a new cold cathode blue-green fluorescent lamp emitting in the 490 nm spectral region. The phototherapy efficiency of the blue-green lamp was found to be almost twice that of standard special blue lamps.