Variation in the Phototherapy Practices and Irradiance of Devices in a Major Metropolitan Area

Preliminary observations of a system for determination of phototherapy exposure over a neonate body shape

While it is possible to determine the irradiance and spectral content for a given neonatal phototherapy device at various locations over a neonate's surface, this does not allow estimation of the total rate of energy delivery within a specific spectral range over the neonate's exposed body surface. A series of 192 blue wavelength enhanced silicon photodiodes was distributed over the surface of a commercially available newborn body shape and connected to a specially designed interface circuit. Placement of photosensors over the surface of the baby shape was determined with consideration of the surface area of twelve specific anatomical areas where each was allocated 16 individual photodiodes. Calibration of detection channels for specific wavelength intervals was undertaken using a Bentham dmc150 spectroradiometer system and also a separate hand held spectroradiometer. This made it possible to estimate the effective integrated dose rate in Watts for specific wavelength intervals such as 460 nm to 490 nm as identified by the American Academy of Pediatrics for phototherapy lamp devices. This allowed identification of dose rate contributions from specific anatomical areas. Initial observations are reported for a range of phototherapy lamp systems and the findings are discussed in terms of their predicted relative clinical effectiveness. Options are also discussed in relation to the future development of the reported measurement system.

White LED phototherapy as an improved treatment for neonatal jaundice

With the aim of improving phototherapy for neonatal jaundice (hyperbilirubinemia), this study investigates the degradation of unconjugated bilirubin under irradiance by conventional light and by white, red, green, and blue LED sources in vitro. The absorption spectra of bilirubin under these different light sources are compared. The results demonstrate that white LED phototherapy promotes more efficient bilirubin degradation than conventional blue-light therapy. This study provides a basis for the design of novel phototherapy devices for the treatment of hyperbilirubinemia.

Acute bilirubin encephalopathy: Some lessons learned

Acute bilirubin encephalopathy (ABE) is still an insufficiently addressed cause of mortality and long-term morbidity in low- and middle-income countries (LMICs). This article highlights that delayed or incorrect medical advice, inaccurate bilirubin measurements as well as ineffective phototherapy are some of the relevant causes predisposing jaundiced newborns to develop extreme hyperbilirubinemia [EHB, total serum/plasma bilirubin (TB) ≥ 25 mg/dL (428 µmol/L)] and subsequent ABE. Obstacles preventing state of the art management of such infants are also discussed. Prevention of ABE cannot occur without a system-based approach tailored to suit the needs and available resources of each community. Clear set protocols, rigorous training, monitoring, and accurate documentation together with simple innovative affordable technologies that can be locally produced, are essential to observe the change desired.

Improving Effectiveness of Phototherapy in an Academic Center: A Quality Improvement Project

Neonatal hyperbilirubinemia is a common cause of delayed discharge and readmissions in our institution. As previously published, the irradiance our phototherapy (PT) units provided was below the irradiance recommended by the AAP for intensive phototherapy (>30 µW/cm²/nm). We measured irradiance delivered by our PT units (Drager 4000) using a standardized footprint grid. By varying number of blue and white fluorescent PT lights, height of PT unit above the neonate and type of bed used (open bassinet versus isolette), we determined the optimal PT arrangement needed to deliver intensive PT (30 µW/cm²/nm). We then developed a standardized, multidisciplinary protocol specifying light arrangement and distance required needed to achieve the desired irradiance level. We were able to show improved irradiance following above changes. Onsite measurement of irradiance provided by local phototherapy units and development of a multidisciplinary, standardized protocol are necessary to assure delivery of recommended levels PT for neonates with hyperbilirubinemia.

An evaluation of phototherapy device performance in a tertiary health facility

INTRODUCTION

A range of phototherapy devices are commercially available. The American Academy of Pediatrics (2004) recommends routine intensity measurement of phototherapy devices to ensure that babies affected by hyperbilirubinemia receive effective phototherapy.

OBJECTIVE

The aims of this study were to calculate the irradiance decay velocity of phototherapy devices used in a tertiary care hospital to evaluate whether current maintenance procedures for phototherapy devices are effective, and to contribute to the improvement of a standardized maintenance procedure in daily practice, thus helping to ensure that all babies affected by hyperbilirubinemia receive prompt treatment.

METHODS

This research represents a prospective observational study conducted at Dr. Soetomo Academic Teaching Hospital in Surabaya, Indonesia from February 2019-July 2019. The intensities of 11 phototherapy devices were measured at specific times using a Bili Blanket Meter II. We calculated the Δ irradiance differences in μW/cm2/nm and calculated them as velocity μW/cm2/nm/hour of use.

RESULTS

Among the 11 phototherapy devices included in this study, nine were fluorescent and two were light-emitting diode (LED) machines. The mean (standard deviation) irradiance decay velocity of the fluorescent lamps was 0.02 (±0.03) μW/cm2/nm/hour of use, while that of the LED lamps was 0.015 (±0.007) μW/cm2/nm/hour of use. The fastest irradiance decay velocity was 0.08 μW/cm2/nm/hour of use, while the slowest irradiance decay velocity was <0.01 μW/cm2/nm/hour of use, both of which were from fluorescent-based devices. There was one fluorescent-based device that provided an intensity lower than the therapeutic level.

CONCLUSION

Irradiance decay occurred in all phototherapy device lamps. It is important to perform routinely intensity measurements, regardless of manufacturer recommendations, to avoid ineffective phototherapy resulting from intensities lower than the required therapeutic levels.

Molecular Physiology and Pathophysiology of Bilirubin Handling by the Blood, Liver, Intestine, and Brain in the Newborn

Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.

Comparative outcome of overhead and total body phototherapy for treatment of severe neonatal jaundice in Nigeria

Background: In Nigeria, neonatal jaundice is commonly treated by overhead phototherapy with neonates lying supine, often with effective exposure of less than one half of the body surface. Total body exposure in phototherapy has been in use for less than 2 years in Nigeria, but is available in only five neonatal centres.Aim: To compare the effectiveness of total body exposure (TBPE) with the conventional partial exposure (COPT) for treatment of hyperbilirubinaemia.Methods: Eleven datasets from 10 neonatal units across Nigeria were retrieved. They included neonates with severe hyperbilirubinaemia treated with TBPE using the Firefly® device (MTTS Asia) as a test group. The remainder of the patients, the controls, were treated with COPT. Any requirement for exchange blood transfusion (EBT) in either group was documented. Total serum bilirubin (TSB) >213.8 μmol/L (12.5 mg/dL) was treated as severe hyperbilirubinaemia. The efficiency of the intervention was determined according to the time taken for a severe case to be downgraded to mild at ≤213.8 μmol/L.Results: A total of 486 patients were studied, 343 controls and 143 cases. Mean (SD) postnatal age was 6 days (0.7) for cases and 5 (0.9) for controls, for gestational age (GA) in completed weeks was 36 (0.5) for cases and 37 (0.7) for controls and for birthweight was 2.7 kg (0.25) for cases and 2.7 (0.22) for controls. Mean (SD) pre-intervention TSB was 299.3 (35.7) μmol/L for cases and 327.3 (13.9) for controls. Severity downgrade day was Day 2 (0.4) for cases and Day 5 (1.1) for controls. Overall relative EBT rate was 6% for cases and 55% for controls (p= 0.0001), and early preterm relative EBT rate was 0% for cases and 68% for controls (p < 0.01).Conclusion: TBPE was quicker and safer for reduction of hyperbilirubinaemia and patients rarely required EBT. TBPE is recommended for rapid reduction of serum bilirubin levels and the reduction of treatment costs, morbidity and mortality in low- and middle-income countries.Abbreviations: EBT, exchange blood transfusion; TBPE, total body exposure technique; COPT, conventional partial exposure; TSB, total serum bilirubin; SB, serum bilirubin; NNJ, neonatal jaundice; SCNU, special care neonatal unit; LMIC, low- and middle-income countries; HIC, high-income countries; LED, light-emitting diode.

Oxidative stress and endoreduplication induced by blue light exposure to CHO cells

Blue light is commonly used for the treatment of Neonatal Jaundice and as a photodynamic therapy for cancer. In comparison to ultraviolet light, blue light has a lower toxicity due to the differences in photon energies. However, blue light can still be mutagenic to cells. The proposed mechanism suggests blue light exposure induces reactive oxygen species inducing oxidative stress. In this study, we examined how blue light exposure caused genotoxic effects utilizing Chinese hamster ovary (CHO) cells and UV135 cells when exposed to fluorescent blue light. Cytotoxic effects of blue light exposure were quantified through cellular oxidative stress analysis, cell survival assay, and in cell cycle arrest experiments. Genotoxicity was studied in sister chromatid exchange (SCE) only, and endoreduplication formation. Following blue light exposure, an increase of cell cycle arrest, oxidative stress, and cytotoxicity was observed. Blue light treatment also produced an increased amount of SCE, and more importantly, induced endoreduplicated chromosomes. In conclusion, exposure to blue light resulted in significant genotoxicity of the treated cells.