Thomas R. C. Sisson

Phototherapy of jaundice in the newborn infant. II. Effect of various light intensities

In a controlled study, three types of fluorescent lamps—“daylight”, standard blue, and special narrow-spectrum blue—were compared in respect to their effects on serum bilirubin concentrations of 72 newborn infants with physiologic jaundice. The narrow-spectrum blue lamps, although they were the least luminous, had the highest energy output in the blue region and were the most effective in treating hyperbilirubinemia. The least efficient lamps were of the “daylight” type. A dose-response relationship of visible light to therapeutic effectiveness was demonstrated.

Phototherapy of jaundice in newborn infants. I. ABO blood group incompatibility

A controlled study of phototherapy was carried out in 35 infants with neonatal hyperbilirubinemia due to maternal-fetal ABO blood group incompatibility. Sixteen of the subjects weighed less than 2,500 Gm. at birth, and 19 weighed 2,500 Gm. or more. Phototherapy caused a marked decline of serum bilirubin concentration at a time when such levels were rising in the control infants and prevented mean peak bilirubin concentrations in the treated infants from reaching the levels attained by the control infants. No treated infants required exchange transfusion, but 5 of the control infants did. The heavier skin pigmentation in Negro subjects did not reduce the effectiveness of phototherapy.

Blue Lamps in Phototherapy of Hyperbilirubinemia

Irradiations using a variety of fluorescent lamps have shown that a special blue lamp emitting a narrow band peaking at 445 nm was most effective in decomposing bilirubin in vitro and in vivo. Standard blue and daylight fluorescent lamps were less effective in decomposing bilirubin. Emission characteristics of the special blue lamps are presented and compared to those of the other lamps evaluated in this application.

Visible Light Therapy of Neonatal Hyperbilirubinemia

In 1877 General Augustus J. Pleasonton proposed, in a remarkable address to the Philadelphia Society for Promoting Agriculture, that blue light would cure certain diseases and increase the yield of crops and the fecundity of domestic beasts. His proposals were buttressed with the results of his own research—an endeavor permitted the educated amateur in those days. He published his work in a book, tastefully bound and printed in blue (Fig. 1). Within a year a preposterous craze for blue light spread across the country which lasted for over a decade. Interest in blue light (sunlight filtered through blue glass) gradually waned, and for the next 70 or more years the medicinal virtues of light (except heliotherapy for the treatment of tuberculosis) were accepted only by cultists and quacks. Perhaps because of this unfortunate, almost ludicrous history, American physicians rejected any Fig. 1. “Phototherapy” 100 years ago. The first American treatise on the uses of blue light. thought of light as a mode of medical treatment and ignored its use in the management of jaundice in the newborn infant, a condition which, if unchecked, can be crippling to a severe degree.

PHOTOTHERAPY: A SYMPOSIUM 3rd Annual Meeting, American Society for Photobiology 22–26 June, 1975, Louisville, KY, U.S.A.

Since the classic paper of Cremer, Perryman and Richards in 1958, phototherapy has meant the treatment of hyperbilirubinemia in the newborn by visible light radiation propagated by fluorescent lamps. Virtually ignored in this country until 1967, a remarkable surge of interest arose then, and the term ‘phototherapy’ has referred only to this one therapeutic venture. More recently it has become evident that such a definition was illogically restrictive, for visible and near U V light have been found to produce other therapeutic results of singular effectiveness. In an effort to bring together for joint exposure and discussion these newer modalities-some of them not so much new as renewed-a symposium on phototherapy was held at the 3rd annual meeting of the American Society for Photobiology. Jaime Kapitulnik* presented a paper on the “Effccts of Light on the Metabolism of Natural Body Constituents and Xenobiotic Compounds”, in which he discussed the catalytic impetus that light, visible and UV, imparts to chemical reactions in a variety of biological systems. He pointed out that the formation of pyrimidine dimers in DNA molecules of skin exposed to UV is a directly damaging effect, enzymatic repair of which is, in turn, activated by visible light. Exposure of human skin to UV causes the formation of cholesterol-5,6-epoxide, which is a known carcinogen. At the same time, the photochemical conversion of molecularly related precursors of vitamin D is also induced by UV, demonstrating a beneficial rather than detrimental effect. The formation of singlet oxygen by light in the presence of photosensitizers is of enormous importance in understanding the reactions of enzymatic oxygenation systems. It is of direct clinical significance in the degradation of bilirubin by visible light. It has been shown, for instance, that riboflavine increases the rate of bilirubin photo-breakdown. Visible light in the presence of riboflavine and methionine

Phenobarbital and Neonatal Jaundice: The Need for More Knowledge

a relatively uncharted area. There are reports that the feeding of substances to adsorb bilirubin in the gut, such as charcoal,1 ’ci~c~3~styramine ~ and agar,3 will reduce plasma bilirubin levels by inhibiting the entero-hepatic recirculation of the pigment. Advantage is being taken of the capacity of certain drugs to lower or prevent the rise of bilirubin concentrations in the blood. These include diethyl nic~tinan3.i~le,~ orotic acid 5 and barbiturates. Basing therapy on known pharn~acologic actions has far more appeal than reliance on empirical results.

Phototherapy of Neonatal Jaundice: Effect on Blood Biorhythms

The biologic effects of visible light upon the mamalian organism have proven to be as marked as those from any other agency in our environment. Because light pervades more than half our days and is a benign, not to say beneficial, force, and is even less tangible than the air, we have seldom had reason to consider its less benevolent activities.