Green light-emitting diode phototherapy for neonatal hyperbilirubinemia: Randomized controlled trial

Action spectrum of phototherapy in hyperbilirubinemic neonates

BACKGROUND

Phototherapy with blue light matching plasma absorption spectrum of the bilirubin-albumin complex with peak at 460 nm is standard treatment of neonatal hyperbilirubinemia.

AIM

To demonstrate clinically the action (efficacy) spectrum of phototherapy in hyperbilirubinemic neonates, through determination of the fraction of total serum bilirubin (TSB) decreased by phototherapy with peak emission wavelengths ≥478 nm (blue-green) compared with that of light of 459/452 nm (blue).

METHODS

TSB values were compiled from three earlier trials, in which hyperbilirubinemic neonates were randomized to receive 24 h of either blue-green light (478/490/497 nm) (intervention groups) or blue light (459/452/459 nm) (control groups) with equal irradiance and exposed body surface areas. Ratios (efficacy) between the decrease in TSB between intervention and control groups were calculated and graphed versus peak wavelengths, demonstrating the course of the action spectrum.

RESULTS

Calculated efficacy ratios were 1.31, 1.18, and 1.04 for light with peak wavelengths of 478, 490, and 497 nm, respectively. The action spectrum increases from 452/459 to maximum at 478 nm, from where it decreases to 1.18 and finally to 1.04.

CONCLUSION

For optimal phototherapeutic treatment, neonates need to be exposed to light with peak wavelength some 20 nm longer than is presently used.

IMPACT

The action (efficacy) spectrum of phototherapy for hyperbilirubinemic neonates has its peak wavelength at 478 nm. The peak wavelength of this action spectrum is 20 nm longer than the wavelength presently believed to be most efficient. The peak is also different from the peak found in vitro. For optimal phototherapeutic effect, neonates need to be treated with light of wavelengths some 20 nm longer than are presently used.

Efficacy of Circumferential Intensive Phototherapy in Treating Neonatal Hyperbilirubinemia: A Pilot Study

OBJECTIVE

The present study was aimed at developing a circumferential phototherapy unit using 3M reflective materials in the double-sided phototherapy unit and investigating its efficacy in treating neonatal hyperbilirubinemia.

STUDY DESIGN

Forty-two infants with neonatal hyperbilirubinemia were selected from our hospital; they were randomly divided into control (n = 21) and experimental groups (n = 21). The experimental group was treated with the circumferential phototherapy unit, while the control group was treated with an ordinary phototherapy unit.

RESULTS

No significant differences were noted between the two groups in the levels of transcutaneous bilirubin before phototherapy (p > 0.05). After 12 hours of phototherapy, the value of transcutaneous bilirubin decreased significantly in the experimental group compared with that of the control group (p < 0.05). Additionally, the two groups did not exhibit any significant difference in the side effects (p > 0.05).

CONCLUSION

Our results indicated that the circumferential phototherapy unit was more effective than the ordinary phototherapy unit in treating neonatal hyperbilirubinemia.

KEY POINTS

· A circumferential phototherapy unit was developed using 3M reflective materials.. · The circumferential phototherapy unit was more effective than the ordinary.. · The two groups did not exhibit any significant difference in the side effects..

Fetal and neonatal bilirubin metabolism

Human fetal and neonatal bilirubin metabolism is centered on 4Z,15Z-bilirubin IXα (BR) due to the extremely low BR conjugating capacity of the liver. BR is a unique, highly lipophilic substance with physiological and toxic effects in the cell membranes of organs and body tissues. The fetus excretes BR through the placenta to the maternal circulation. After birth, BR is thought to act as an antioxidant against the increase in reactive oxygen species caused by the rapid increase in oxygen concentration during the adaptation process from in amniotic fluid to in air. However, bilirubin encephalopathy is a toxic effect of bilirubin. Due to the lipophilic nature of BR, it must be bound to a carrier to be distributed to various parts of the body by hydrophilic blood. This carrier of BR is human serum albumin (HSA). In humans, BR can be excreted efficiently after undergoing photochemical reactions upon high affinity binding to HSA. HSA also plays an important role in the prevention of bilirubin encephalopathy. This review focuses on the developmental and physiological role of bilirubin metabolism during the fetal and neonatal periods.

Characteristics of bilirubin photochemical changes under green light-emitting diodes in humans compared with animal species

Phototherapy using light-emitting diodes (LEDs) centered on the green spectrum, which has a high cyclobilirubin production rate, was as effective as that centered on the blue spectrum for neonatal hyperbilirubinemia. There are no reports of species differences in bilirubin photochemical changes in this spectrum, and the characteristics of bilirubin photochemical changes in humans must be elucidated to proceed with the development of new light sources that include these spectra. This report describes the characteristic photochemical kinetics of bilirubin under green-spectrum LEDs in human, rat, rabbit, dog, pig, sheep, bovine and chicken serum albumin and rhesus monkey serum. These albumin-bilirubin complex solutions were irradiated by green LEDs, and the time-course changes in bilirubin photoisomers were measured by high-performance liquid chromatography. The cyclobilirubin production rates in humans, pigs, and monkeys were significantly higher than those in other species. The rate constant of (EZ)-cyclobilirubin production from (EZ)-bilirubin 'k' was significantly higher in humans and monkeys than in other species. In conclusion, bilirubin photochemical kinetics under green spectrum LEDs in humans were characterized by a high cyclobilirubin production rate at a low substrate concentration. The bilirubin photochemical kinetics in monkeys were similar to those in humans.

Green light extends Drosophila longevity

The role of visible light on longevity is incompletely understood. Here we show the effect of visible light in Drosophila melanogaster is wavelength specific. Life span was significantly extended by green light, whereas blue light reduced longevity dramatically, and minor impact was observed with red light. While oxidative stress, heat stress, or caloric restriction does not contribute to the beneficial effect of green light, our study found that the life span extension effect of green light might be mediated by microbiota or photosensitive micronutrients in food medium. In conclusion, we report that green light can extend longevity and present the potential of light as a noninvasive therapy for aging-related diseases.

The effectiveness of phototherapy using blue-green light for neonatal hyperbilirubinemia - Danish clinical trials

The effectiveness of phototherapy for neonatal hyperbilirubinemia based on Danish clinical trials is presented. Randomized controlled trials on the quality of light showed that blue-green fluorescent light (peak emission at 490 nm) was more efficient than blue fluorescent light (peak emission at 452 nm); blue-green light-emitting diode (LED) light (peak emission at 478 nm) was more efficient than blue LED light (peak emission at 459 nm); and blue-green LED light (peak emission at 497 nm) was equivalent to blue LED light (peak emission at 459 nm). Bilirubin-reducing effects correlated with irradiance, dependent on hemoglobin concentration, and independent of rotating infants. Phototherapy from both above and below was more efficient than therapy applied only from above at high levels of irradiance. In conclusion, we estimate and recommend the use of blue-green LED light (peak emission at 480 nm) rather than blue light (peak emission at 460 nm) for treating of neonatal hyperbilirubinemia.

Challenges of phototherapy for neonatal hyperbilirubinemia (Review)

Phototherapy is universally recognized as the first option for treating neonatal jaundice due to its unparalleled efficiency and safety in reducing the high serum free bilirubin levels and limiting its neurotoxic effects. However, several studies have suggested that phototherapy may elicit a series of short- and long-term adverse reactions associated with pediatric diseases, including hemolysis, allergic diseases, DNA damage or even cancer. The aim of the present review was to summarize the etiology, mechanism, associated risks and therapeutic strategies for reducing high neonatal serum bilirubin levels. In order to shed light on the negative effects of phototherapy and to encourage implementation of a reasonable and standardized phototherapy scheme in the clinic, the present review sought to highlight the current understanding of the adverse reactions of phototherapy, as it is necessary to further study the mechanism underlying the development of the adverse effects of phototherapy in infants in order to explore novel therapeutic alternatives.

Mild neonatal complications following guideline-compliant vacuum-assisted delivery in Japan: improvements still needed

INTRODUCTION

Neonatal cephalohematoma and hyperbilirubinemia are often encountered after vacuum-assisted delivery. For safe obstetric practice, guidelines for vacuum procedure were published in 2014 in Japan. We aimed to identify the risk of mild neonatal complications since guideline introduction.

METHODS

This retrospective observational study included singleton deliveries at term gestation from 2015 to 2019 at a single perinatal center in Japan. Incidences of neonatal jaundice requiring phototherapy, cephalohematoma, and umbilical artery pH <7.10 were determined and risk factors relevant to the development of hyperbilirubinemia were evaluated.

RESULTS

Of 1010 deliveries during the study period, vacuum procedures were attempted in 183 (18%). Guideline recommendations were fully adhered to in over 98% of vacuum procedures. Phototherapy for neonatal hyperbilirubinemia was performed in 75 (41%) of 183 deliveries with vacuum procedure, cephalohematoma occurred in 35 (19%), and umbilical artery pH <7.10 was observed in 10 (5.5%), all of which were significantly higher than without vacuum procedure, such as hyperbilirubinemia (11%, risk ratio [RR] = 3.8, 95% confidence interval [CI] = 2.9 - 4.9, p < .0001), cephalohematoma (1.0%, RR = 19.8, 95%CI = 9.3 - 41.9, p < .0001), and umbilical artery pH <7.10 (0.6%, RR = 9.0, 95%CI = 3.1 - 26.1, p < .0001). Multiple logistic regression analysis demonstrated that vacuum procedure was the factor most strongly associated with neonatal hyperbilirubinemia (odds ratio = 3.5, 95%CI = 2.2 - 5.5, p < .0001).

DISCUSSION

Vacuum procedure is an important option for the safe vaginal delivery. However, neonates should be observed for development of jaundice to prevent kernicterus even after optimally performed vacuum-assisted delivery.