Dose-response relationship of phototherapy for hyperbilirubinemia

Clinical overview of phototherapy for neonatal hyperbilirubinaemia

The most efficient emission spectrum of light for phototherapy is blue-green light emission diode light with peak emission at 478 nm. In the irradiance interval of phototherapy, the relationship between efficacy and irradiance is almost linear, and it is negatively related to the haemoglobin. The action sites of phototherapy are the extravascular compartment and cutaneous blood. The most immature neonates treated aggressively had not only a lower frequency of neurodevelopmental impairment than conservatively treated, but also greater mortality. Intermittent and continuous phototherapy are assumed to be equally efficient. Home-based fibreoptic phototherapy is effective and safe. Important progress is still occurring in phototherapy.

Phototherapy to Prevent Severe Neonatal Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation: Technical Report

OBJECTIVE

To summarize the principles and application of phototherapy consistent with the current 2022 American Academy of Pediatrics "Clinical Practice Guideline Revision for the Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation."

METHODS

Relevant literature was reviewed regarding phototherapy devices in the United States, specifically those that incorporate blue to blue-green light-emitting diode, fluorescent, halogen, or fiberoptic light sources, and their currently marketed indications.

RESULTS

The efficacy of phototherapy devices varies widely because of nonstandardized use of light sources and configurations and irradiance meters. In summary, the most effective and safest devices have the following characteristics: (1) incorporation of narrow band blue-to-green light-emitting diode lamps (∼460-490 nm wavelength range; 478 nm optimal) that would best overlap the bilirubin absorption spectrum; (2) emission of irradiance of at least 30 µW/cm2/nm (in term infants); and (3) illumination of the exposed maximal body surface area of an infant (35% to 80%). Furthermore, accurate irradiance measurements should be performed using the appropriate irradiance meter calibrated for the wavelength range delivered by the phototherapy device.

CONCLUSIONS

With proper administration of effective phototherapy to an infant without concurrent hemolysis, total serum or plasma bilirubin concentrations will decrease within the first 4 to 6 hours of initiation safely and effectively.

Current status of neonatal jaundice management in Japan

BACKGROUND

This nationwide survey aimed to determine the status of jaundice management in Japan.

METHODS

A questionnaire about bilirubin level measurements and neonatal jaundice treatment was sent to 330 institutions providing neonatal care. The responses were analyzed according to institution level.

RESULTS

Of 330 institutions, 172 responded (52.1% response rate). Total bilirubin levels were measured in the central laboratory using spectrophotometry at 134 institutions and a blood gas analyzer at 81 institutions. Unbound bilirubin (UB) levels were measured by 79 institutions, while transcutaneous bilirubin measurements were taken at 63 institutions. There was no association between institution level and UB or transcutaneous bilirubin measurement. For phototherapy criteria, the Murata-Imura criteria were adopted by 67 institutions, Nakamura criteria by 36, and Morioka criteria by 39. Light-emitting diodes (LED) were used by 160 institutions versus fluorescent lights by 31. When a blue LED was used, 119 institutions used the high mode. There is no standard for increasing light intensity. No association was found between institution level and phototherapy criteria. UB was measured in 14 of 63 institutions using the Murata-Imura criteria.

CONCLUSIONS

There is a large variation in the management and treatment of neonatal jaundice among institutes in Japan.

Cardiovascular changes during phototherapy in newborns

Phototherapy is the most effective non-invasive method of neonatal hyperbilirubinemia treatment. Application of this method can be associated with side effects including changes in the cardiovascular system. During phototherapy, the primary effects in the cardiovascular system include cutaneous vasodilation leading to skin hyperperfusion and subsequent redistribution of blood. The increased blood flow through the skin is associated with increased transepidermal water loss. Further effects include an increase in cerebral blood flow. Redistribution of blood to the cutaneous bed is compensated by hypoperfusion in the splanchnic area (mostly postprandial) and a significant reduction of the renal blood flow. Regarding closure/reopening of the ductus arteriosus, the results suggest that that phototherapy does not affect ductal patency. During phototherapy the cardiac output can be slightly reduced due to a decreased stroke volume, especially in preterm newborns. Systemic blood pressure is decreased and heart rate is elevated in both preterm and term newborns during phototherapy. The heart rate variability is slightly reduced. Symbolic dynamics analysis of the short-term HRV showed that during phototherapy the activity of the ANS regulating the heart rate is shifted towards the dominancy of the sympathetic activity. The responses in the cardiovascular system of premature/mature newborns without other pathology confirm a well physiologically functioning control of this system, even under specific conditions of phototherapy.

Effectiveness of Dual-Blanket Phototherapy Compared With Combination Phototherapy on Rate of Bilirubin Decline and Treatment Duration

INTRODUCTION

The purpose of this study was to evaluate the effectiveness of dual light-emitting diode (LED) blanket phototherapy compared with combination LED phototherapy on the rate of total serum bilirubin (TSB) decline and treatment duration among full-term neonates with hyperbilirubinemia.

METHODS

A retrospective chart review of 255 newborns with hyperbilirubinemia admitted to a free-standing, university-affiliated, nonprofit, tertiary care Children's Hospital was conducted. Phototherapy type, duration, and rate of TSB decline were compared.

RESULTS

The rate of TSB decline was significantly higher among neonates treated with combination LED phototherapy than neonates treated with dual-blanket phototherapy (p <.0001). There was no significant difference in phototherapy duration.

DISCUSSION

Combination phototherapy resulted in a more rapid decline in TSB but did not shorten phototherapy duration compared to dual-blanket phototherapy. Phototherapy duration may have been confounded by variability in the timing of TSB laboratory draws. Further comparative effectiveness studies are recommended.

Irradiance footprint of phototherapy devices: a comparative study

BACKGROUND

Phototherapy (PT) is the standard treatment of neonatal unconjugated hyperbilirubinemia. The irradiance footprint, i.e., the illuminated area by the PT device with sufficient spectral irradiance, is essential for PT to be effective. Irradiance footprint measurements are not performed in current clinical practice. We describe a user-friendly method to systematically evaluate the high spectral irradiance (HSI) footprint (illuminated area with spectral irradiance of ≥30 μW cm^-2 nm^-1) of PT devices in clinical practice.

MATERIALS AND METHODS

Six commercially available LED-based overhead PT devices were evaluated in overhead configuration with an incubator. Spectral irradiance (µW cm^-2 nm^-1) and HSI footprint were measured with a radiospectrometer (BiliBlanket Meter II).

RESULTS

The average measured spectral irradiance ranged between 27 and 52 μW cm^-2 nm^-1 and HSI footprint ranged between 67 and 1465 cm², respectively. Three, two, and one PT devices out of six covered the average BSA of an infant born at 22, 26-32, and 40 weeks of gestation, respectively.

CONCLUSION

Spectral irradiance of LED-based overhead PT devices is often lower than manufacturer's specifications, and HSI footprints not always cover the average BSA of a newborn infant. The proposed measurement method will contribute to awareness of the importance of irradiance level as well as footprint measurements in the management of neonatal jaundice.

IMPACT

While a sufficient spectral irradiance footprint is essential for PT to be effective, some PT devices have spectral irradiance footprints that are too small to cover the entire body surface area (BSA) of a newborn infant. This study introduces a user-friendly, accessible method to systematically evaluate the spectral irradiance level and footprint of PT devices. This study supports awareness on the role of the spectral irradiance footprint in the efficacy of PT devices. Irradiance footprint can be easily measured during phototherapy with the proposed method.

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.

Hyperbilirubinemia in the Term Infant: Re-evaluating What We Think We Know

This article attempts to highlight contemporary issues relating to term neonatal hyperbilirubinemia and to focus attention on controversial issues and concepts with the potential to effect change in clinical approach. On the one hand, the focus is bilirubin neurotoxicity, which is now known to encompass a wide, diverse spectrum of features. The various aspects of this spectrum are outlined and defined. On the other hand, bilirubin also possesses antioxidant properties. As such, mild hyperbilirubinemia is suggested as actually offering the neonate some protective advantage.

Can exchange transfusion be replaced by double-LED phototherapy?

Phototherapy is a conventional treatment for neonatal jaundice and widely considered as a safe procedure. Recent developments in light-emitting diode (LED) phototherapy devices have made more effective treatments possible. Exchange transfusion (ET) is typically applied for cases of refractory severe hyperbilirubinemia despite its risk of various complications. Since the therapeutic effect of phototherapy is correlated with its irradiance, ET may be avoided by performing phototherapy with higher irradiation. Recently, we adopted double-LED phototherapy as a bridging treatment to ET to treat a case of severe hyperbilirubinemia. In this case, the continual increase of bilirubin levels was suppressed immediately after its administration, and ET was not required. Throughout the treatment, no complications or increase in oxidative stress was observed. In addition, neurodevelopment was appropriate for the patient’s age at the 1-year follow-up, and no findings of kernicterus, including physical and magnetic resonance imaging findings, were observed. We hypothesized that double-LED phototherapy may be a good treatment strategy to replace ET for infants with severe hyperbilirubinemia; however, further investigations regarding safety issues including acute and long-term complications are needed before clinical adaptation.

Phototherapy Using a Light-Emitting Fabric (BUBOLight) Device in the Treatment of Newborn Jaundice: Protocol for an Interventional Feasibility and Safety Study

Background

Neonatal jaundice is a common condition occurring in 60%-80% of all healthy-term and late-preterm neonates. In the majority of cases, neonatal jaundice resolves spontaneously and causes no harm; however, in some neonates, significant hyperbilirubinemia can develop and lead to kernicterus jaundice, a serious neurological disease. Phototherapy (PT) is the preferred treatment for jaundice; however, to be effective, PT devices need to have a broad light emission surface to generate no or little heat and to provide an optimal wavelength and light intensity (420-490 nm and ≥30 µW/cm²/nm, respectively).

Objective

This study aimed to investigate the feasibility, safety, and level of satisfaction of parents and health care teams with the BUBOlight device, an innovative alternative to conventional hospital PT, in which luminous textiles have been incorporated in a sleeping bag.

Methods

This interventional, exploratory, simple group, nonrandomized, single-center trial will be conducted at Lille Hospital. In total, 10-15 neonates and their parents will be included to obtain evaluable data from 10 parent-neonate pairs. Neonates weighing more than 2500 g at birth and born with ≥37 weeks of amenorrhea that required PT in accordance with the guidelines of the National Institute For Health and Clinical Excellence will receive one 4-hour session of illumination. Total serum bilirubin and transcutaneous bilirubin levels were obtained at the start and 2 hours after the end of PT. Cutaneous and rectal temperatures, heart rate, and oxygen saturation will be measured at the beginning and during PT. The number of subjects is therefore not calculated on the basis of statistical assumptions. We aim to obtain a minimum proportion of 90% (ie, 9 of 10) of the neonates included, who have been able to undergo 4-hour PT without unacceptable and unexpected toxicities. We will calculate the mean, median, quartiles, minimum and maximum values of the quantitative parameters, and the frequency of the qualitative parameters. The rate of patients with no unacceptable and unexpected toxicities (ie, the primary endpoint) will be calculated.

Results

The first patient is expected to be enrolled at the end of 2020, and clinical investigations are intended for up to June 2021. The final results of this study are expected to be available at the end of 2021.

Conclusions

Our findings will provide insights into the safety and feasibility of a new PT device based on light-emitting fabrics for the treatment of newborn jaundice. This new system, if proven effective, will improve the humanization of neonatal care and help avoid mother-child separation.

Trial Registration

ClinicalTrials.gov NCT04365998; https://clinicaltrials.gov/ct2/show/NCT04365998

International Registered Report Identifier (IRRID)

PRR1-10.2196/24808

Effect of blue LED phototherapy centered at 478 nm versus 459 nm in hyperbilirubinemic neonates: a randomized study

BACKGROUND

Treatment of choice for hyperbilirubinemic neonates is blue light matching the absorption spectrum of bilirubin-albumin in vitro with maximum absorption at 459 nm. Blue LED light centered at 478 nm was hypothesized as being more efficient than that centered at 459 nm. This study compares the bilirubin-reducing effect of the two light qualities with equal irradiance in a randomized nonblinded clinical trial.

METHODS

Inclusion criteria were healthy hyperbilirubinemic neonates with gestational age ≥33 weeks. Forty-nine neonates included in each group received phototherapy from above for 24 h. Mean irradiances were 9.2 × 10¹⁵ and 9.0 × 10¹⁵ photons/cm²/s for the 478 and 459 nm groups, respectively.

RESULTS

Mean [95% CI] decreases in total serum bilirubin were 150 [141, 158] and 120 [111, 130] µmol/L for the 478 and 459 nm groups, respectively; mean difference was 29 [17, 42] µmol/L. Mean [95% CI] percentage decreases in bilirubin were 54.8% [52.5, 57.0] and 41.8% [39.3, 44.3]; mean difference was 12.9 [9.6, 16.3] percentage points. After adjustment this difference was 13.4 [10.2, 16.7] percentage points. All differences were highly statistically significant (P < 0.001).

CONCLUSION

Blue LED light centered at 478 nm had a greater bilirubin-reducing effect than that centered at 459 nm with equal irradiance quantified as photon fluence rate.

IMPACT

Blue LED light centered at 478 nm had a greater in vivo bilirubin-reducing effect than blue LED light centered at 459 nm with equal irradiance quantified as photon fluence rate in the treatment of hyperbilirubinemic late preterm or term neonates. LED light centered at 478 nm might reduce the duration of phototherapy compared to LED light centered at 459 nm as the same effect can be obtained while exposing the infants to fewer photons. Blue light matching the absorption spectrum of the bilirubin-albumin complex in vitro with peak absorption at 459 nm is used worldwide as it is considered to be the most effective light for phototherapy of jaundiced neonates. This study showed that blue LED light centered at 478 nm had a greater bilirubin-reducing effect than blue LED light centered at 459 nm. Therefore, blue LED light centered at 478 nm should be used instead of blue light centered at 459 nm. By this, the risk of potential side effects might be minimized, and the duration of phototherapy potentially reduced.

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.

Use of reflective materials during phototherapy for newborn infants with unconjugated hyperbilirubinaemia

BACKGROUND

Phototherapy is a well-established effective therapy for treating babies with significant neonatal jaundice. Studies have shown that increasing light intensity will increase its efficiency. A potentially inexpensive and easy way of increasing the intensity of light on the body of the infant may be to hang reflective materials from the sides of phototherapy units.

OBJECTIVES

To assess the effects of reflective materials in combination with phototherapy compared with phototherapy alone for unconjugated hyperbilirubinaemia in neonates.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index of Nursing and Allied Health Literature (CINAHL), on 1 November 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials if the participants, who were term or preterm infants, received phototherapy with curtains made of reflective materials of any type in the treatment arm, and if those in the comparison arm received similar phototherapy without curtains or other intensified phototherapy, such as a double bank of lights.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Of 15 studies identified, we included 12 (1288 babies) in the review - 11 comparing phototherapy with reflective materials and phototherapy alone, and one comparing a single phototherapy light bank with reflective materials with double phototherapy. All reflective materials consisted of curtains on three or four sides of the cot and were made of white plastic (five studies), white linen (two studies), or aluminium (three studies); materials were not specified in two studies. Only 11 studies (10 comparing reflective materials versus none and one comparing reflective curtains and a single bank of lights with a double (above and below) phototherapy unit) provided sufficient data to be included in the meta-analysis. Two excluded studies used the reflective materials in a way that did not meet our inclusion criteria, and we excluded one study because it compared four different phototherapy interventions not including reflective materials. The risk of bias of included studies was generally low, but all studies had high risk of performance bias due to lack of blinding of the intervention. Three studies (281 participants) reported a decline in serum bilirubin (SB) (μmol/L) at four to eight hours (mean difference (MD) -14.61, 95% confidence interval (CI) -19.80 to -9.42; I² = 57%; moderate-certainty evidence). Nine studies (893 participants) reported a decline in SB over 24 hours and showed a faster decline in SB in the intervention group, but heterogeneity (I² = 97%) was too substantial to permit a meaningful estimate of the actual effect size (very low-certainty evidence). Subgroup analysis by type of reflective material used did not explain the heterogeneity. Exchange transfusion was reported by two studies; both reported none in either group. Four studies (466 participants) reported the mean duration of phototherapy, and in each of these studies, it was reduced in the intervention group but there was substantial heterogeneity (I² = 88%), precluding meaningful meta-analysis of data. The only two studies that reported the mean duration of hospital stay in hours showed a meaningful reduction (MD -41.08, 95% CI -45.92 to -36.25; I² = 0; moderate-certainty evidence). No studies reported costs of the intervention, parental or medical staff satisfaction, breastfeeding outcomes, or neurodevelopmental follow-up. The only study that compared use of curtains with double phototherapy reported similar results for both groups. Studies that monitored adverse events did not report increased adverse events related to the use of curtains, including acute life-threatening events, but other rarer side effects could not be excluded.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence shows that the use of reflective curtains during phototherapy may result in greater decline in SB. Very low-certainty evidence suggests that the duration of phototherapy is reduced, and moderate-certainty evidence shows that the duration of hospital stay is also reduced. Available evidence does not show any increase in adverse events, but further studies are needed.

Efficacy of double versus single phototherapy in treatment of neonatal jaundice: a meta-analysis

To assess the efficacy of double phototherapy in managing neonatal jaundice compared to single phototherapy in infants with different birth weight and gestational age. CENTRAL, PubMed, clinicaltrials.gov, and gray literature sources were searched from date of inception of these databases till August 2019. Primary outcome was decline of total serum bilirubin (TSB) per hour. Ten studies were eligible. Our meta-analysis showed significant difference between double phototherapy versus single phototherapy in decline of TSB per hour in preterm infants (standardized mean difference [SMD] = 2.28 [0.79-3.76], p = 0.003) and a significant decrease in TSB levels at 24 h of phototherapy in infants with birth weight ≥ 1500 g (mean difference [MD] = - 61.70 μmol/L, [- 107.96, - 15.43], p = <0.001).Conclusion: Double phototherapy is effective in reducing TSB in infants of different gestational ages and birth weights with the most important finding regarding preterm infants, who are more susceptible to kernicterus.What is Known:• Double phototherapy has shown to be more efficacious than single phototherapy in treating neonatal jaundice.• Double phototherapy efficacy on neonates with different gestational ages and birth weights still remain ambiguous in treating neonatal jaundice.What is New:• The results of this meta-analysis show that double phototherapy is effective in reducing TSB in infants of different gestational ages and birth weights with the most important finding regarding preterm infants, who are more susceptible to kernicterus.

Making Locally Fabricated Phototherapy Devices Work Better

BACKGROUND

The efficiency of a phototherapy (PT) device is a function of the irradiance delivered by the device at the surface of the skin. Because cost limits the ability of health care facilities in low- and middle-income countries to procure commercial PT devices, efforts have gone into local fabrication of devices for use in health care facilities in Nigeria. Evaluation of such fabricated devices is yet to be conducted.

OBJECTIVE

To identify and document essential features of locally fabricated phototherapy (FPT) devices in use in Nigeria.

MATERIALS AND METHODS

A cross sectional survey of locally FPT devices available in health facilities providing newborn health care services was conducted as part of evaluating neonatal jaundice management services in Kaduna State. Each FPT was characterized with respect to mobility/portability, adjustability, lamp type, number and color of lamps used. The irradiance of each device was measured using Model 22 Olympic BiliMeter™ at the facility's traditional PT distance and also at a distance at which optimum irradiance is delivered by the device.

RESULTS

A total of 54 PT devices were in use. Thirty-two (59.3%) of these devices were locally fabricated while others were obtained from commercial sources. Of the fabricated devices 22/32 (68.8%) were non-adjustable while the remaining 10 devices were adjustable but with limited adjustability. Only 5/32 (15.6%) of the FPT devices used special blue fluorescent lamps. The majority, 68.8% (22/32) of the FPT devices used ordinary low-intensity blue lamps while the remaining 5/32 (15.6%) devices used white light fluorescent lamps. None of the devices used light emitting diodes as a PT light source. Only three fabricated devices offered irradiance (9.4, 13.6 and 33 µW/cm2/nm) at the facilities' traditional distances for PT.

CONCLUSIONS

FPT devices in use in Kaduna, functioned sub-optimally because of technically inadequate designs. The devices will need to be designed to especially enable adjustability to vary distance between device and patient's skin and the use of lamps which offer high irradiance.

Sixty years of phototherapy for neonatal jaundice - from serendipitous observation to standardized treatment and rescue for millions

A breakthrough discovery 60 years ago by Cremer et al. has since changed the way we treat infants with hyperbilirubinemia and saved the lives of millions from death and disabilities. "Photobiology" has evolved by inquiry of diverse light sources: fluorescent tubes (wavelength range of 400-520 nm; halogen spotlights that emit circular footprints of light; fiberoptic pads/blankets (mostly, 400-550 nm range) that can be placed in direct contact with skin; and the current narrow-band blue light-emitting diode (LED) light (450-470 nm), which overlaps the peak absorption wavelength (458 nm) for bilirubin photoisomerization. Excessive bombardment with photons has raised concerns for oxidative stress in very low birthweight versus term infants treated aggressively with phototherapy. Increased emphasis on prescribing phototherapy as a "drug" that is dosed cautiously and judiciously is needed. In this historical review, we chronicled the basic to the neurotoxic components of severe neonatal hyperbilirubinemia and the use of standardized interventions.

Evaluation of Rh-Hemolytic Disease in Neonates and Management with Early Intensive Phototherapy in the Neonatal Intensive Care Unit

BACKGROUND OF THE STUDY

In neonates with Rh-hemolytic disease, light emitting diode (LED) phototherapy allows delivery of high spectral irradiance (SI). A linear correlation exists between SI and efficacy of phototherapy with no saturation point. There is scant data on evaluation and early phototherapy using LED units in Rh-hemolytic disease.

OBJECTIVE

This study aimed to describe the hemoglobin (Hb), hematocrit (Hct), total serum bilirubin (TSB), phototherapy parameters and short-term outcomes in neonates with Rh-hemolytic disease.

METHODOLOGY

Maternal parameters for Rh-isoimmunization were recorded and monitoring of fetal anemia by Doppler ultrasound was done. Early intensive phototherapy within 1 h of birth was initiated for cord blood Hb below 13.6 g/dl and/or TSB greater than 2.8 mg/dl.

RESULTS

Fifty Rh positive neonates were enrolled of which 11/50 (22%) received intrauterine transfusions. The maximum TSB remained below 18 mg/dl in 42/50 (84%) of neonates. The mean SI on the trunk was 56.260 ± 8.768 µW/cm2/nm and duration of phototherapy was 7 ± 3.29 days (mean ± SD). There was a positive correlation between strength of indirect antiglobulin test and cord blood Hb: correlation coefficient (r) = 0.295; direct antiglobulin test and duration of phototherapy: r = 0.331. Early packed red blood cell (PRBC) transfusion was required in 8/50 (16%) neonates while 20/50 (40%) required late transfusions.

CONCLUSION

With a mean SI of 56.260 ± 8.768 µW/cm2/nm on the trunk, TSB remained below 18 mg/dl in majority thereby avoiding exchange transfusion. Early or late PRBC transfusion requirement was 1 (1-2) (median ± interquartile range).

Current phototherapy practice on Java, Indonesia

Background

In Indonesia, the burden of severe hyperbilirubinemia is higher compared to other countries. Whether this is related to ineffective phototherapy (PT) is unknown. The aim of this study is to investigate the performance of phototherapy devices in hospitals on Java, Indonesia.

Methods

In 17 hospitals we measured 77 combinations of 20 different phototherapy devices, with and without curtains drawn around the incubator/crib. With a model to mimic the silhouette of an infant, we measured the irradiance levels with an Ohmeda BiliBlanket Meter II, recorded the distance between device and model, and compared these to manufacturers’ specifications.

Results

In nine hospitals the irradiance levels were less than required for standard PT: < 10 μW/cm²/nm and in eight hospitals irradiance failed to reach the levels for intensive phototherapy: 30 μW/cm²/nm. Three hospitals provided very high irradiance levels: > 50 μW/cm²/nm. Half of the distances between device and model were greater than recommended. Distance was inversely correlated with irradiance levels (R² = 0.1838; P < 0.05). The effect of curtains on irradiance levels was highly variable, ranging from − 6.15 to + 15.4 μW/cm2/nm, with a mean difference (SD) of 1.82 (3.81) μW/cm2/nm (P = 0.486).

Conclusions

In half of the hospitals that we studied on Java the levels of irradiance are too low and, in some cases, too high. Given the risks of insufficient phototherapy or adverse effects, we recommend that manufacturers provide radiometers so hospitals can optimize the performance of their phototherapy devices.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1552-1) contains supplementary material, which is available to authorized users.

The effect of light wavelength on in vitro bilirubin photodegradation and photoisomer production

BACKGROUND

The action spectrum for bilirubin photodegradation has been intensively studied. However, questions still remain regarding which light wavelength most efficiently photodegrades bilirubin. In this study, we determined the in vitro effects of different irradiation wavelength ranges on bilirubin photodegradation.

METHODS

In our in vitro method, normalized absolute irradiance levels of 4.2 × 10¹⁵ photons/cm²/s from light-emitting diodes (ranging from 390-530 nm) and 10-nm band-pass filters were used to irradiate bilirubin solutions (25 mg/dL in 4% human serum albumin). Bilirubin and its major photoisomer concentrations were determined; the half-life time of bilirubin (t_1/2) was calculated for each wavelength range, and the spectral characteristics for bilirubin photodegradation products were obtained for key wavelengths.

RESULTS

The in vitro photodegradation of bilirubin at 37 °C decreased linearly as the wavelength was increased from 390 to 500 nm with t_1/2 decreasing from 63 to 17 min, respectively. At 460 ± 10 nm, a significantly lower rate of photodegradation and thus higher t_1/2 (31 min) than that at 500 nm (17 min) was demonstrated.

CONCLUSION

In our system, the optimum bilirubin photodegradation and lumirubin production rates occurred between 490 and 500 nm. Spectra shapes were remarkably similar, suggesting that lumirubin production was the major process of bilirubin photodegradation.

[Effectiveness and safety of two phototherapy devices for the humanised management of neonatal jaundice]

INTRODUCTION

Neonatal jaundice is common, especially in premature infants. Compliance with treatment protocols and standard serum bilirubin curves forces the clinician to separate the child from the mother after birth for short phototherapy. The objective of this study is to evaluate the effectiveness and safety of two innovative devices for phototherapy including a LED light mesh: one sleeping bag and one blanket compared to conventional hospital or ambulatory phototherapy.

METHODS

Two randomised clinical trials were conducted: one with newborns >2,000g at birth in the Neonatal Care Unit and the other with premature infants followed-up in an outpatient clinic (PMC). The gold standard for bilirubin measurement was serum bilirubin, and ambulatory controls were performed with the Bilicheck®. Parents and health personnel completed a questionnaire on comfort and perceptions.

RESULTS

In the study using the bag, a linear regression was performed for the decrease in bilirubin in mg/dL/h, controlling by early jaundice (<36h) and the device type. The results were similar between the 2 devices. For the blanket trial in the PMC, the decrease in bilirubin levels with the new device was significantly greater with no differences in temperatures, duration of phototherapy, re-admission, mortality, or side effects for both trials. Parents and staff satisfaction with the two devices was identical for the 2 trials.

CONCLUSION

These 2 small studies add a 'grain of sand' to humanisation of newborn care, avoiding the mother-and-child separation for both the intra-hospital high-risk hyperbilirubinaemia, as well as for the lower-risk hyperbilirubinaemia in an outpatient clinic.

Light-induced morphological transition between unconjugated bilirubin photoisomers

Morphology switching by an external stimulus creates the possibility to detect and control the activity and functionality of bio-molecules. Unconjugated bilirubin (UCB), a waste product resulting from heme catabolism, is highly sensitive towards blue light induced configurational conversion from (4Z,15Z) to (4Z,15E)-bilirubin. UCB has a distinct elongated nanostructure which is readily photoswitchable to spherical by external blue light (470 nm) irradiation. Herein, the morphology alteration by blue light was nicely correlated with the photoisomerisation of UCB, using different microscopic and spectroscopic techniques. To restrict the other photo-incidents during phototreatment on UCB, a suitable time frame was calibrated by monitoring the absorption, HPLC, lifetime distribution and ¹H NMR studies. Furthermore, by the help of this morphological transition as a marker, UCB early stage photoisomerisation has also been triggered by two-photon irradiation (940 nm).

Phototherapy and its effect on some physiological functions in newborns

Phototherapy represents the most common therapeutic intervention at neonatology departments in the first days of life. The beneficial effects of light on the decrease of the serum bilirubin level were first described by Cremer et al. in 1950’s (1). Since then phototherapy has been successfully used to treat severe hyperbilirubinaemia and has almost completely replaced exchange transfusion. Phototherapy is a relatively non-invasive method. However, along with decreasing bilirubin level, it can also influence some other functions: perfusion of organs, predominantly skin; peripheral vascular resistance; distribution of blood flow; heart activity and, thus, also systemic blood pressure along with breathing. A side component of applied light is a certain amount of heat which warms the body surface up and, therefore, the risk of exogenous overheating and increased water loss through the skin arise. Maternal-infant separation, modification of calcium homeostasis, disturbed circadian rhythm, or changes of the hemodynamics of various organ systems are only a few of the undesired effects which prove phototherapy not to be a treatment without any side effects. Careful indication of phototherapy is essential, particularly in premature infants.

Hyperbilirubinemia in preterm infants in Japan: New treatment criteria

In 1992, Kobe University proposed treatment criteria for hyperbilirubinemia in newborns using total serum bilirubin and serum unbound bilirubin reference values. In the last decade, chronic bilirubin encephalopathy has been found to develop in preterm infants in Japan because it can now be clinically diagnosed based on an abnormal signal of the globus pallidus on T2-weighted magnetic resonance imaging and abnormal auditory brainstem response with or without apparent hearing loss, along with physical findings of kinetic disorders with athetosis. We therefore revised the Kobe University treatment criteria for preterm hyperbilirubinemic infants in 2017. The three revised points are as follows: (i) newborns are classified under gestational age at birth or corrected gestational age, not birthweight; (ii) three treatment options were created: standard phototherapy, intensive phototherapy, and albumin therapy and/or exchange blood transfusion; and (iii) initiation of standard phototherapy, intensive phototherapy, and albumin therapy and/or exchange blood transfusion is decided based on the total serum bilirubin and serum unbound bilirubin reference values for gestational weeks at birth at <7 days of age, and on the reference values for corrected gestational age at ≥7 days of age. Studies are needed to establish whether chronic bilirubin encephalopathy can be prevented using the 2017 revised Kobe University treatment criteria for preterm infants in Japan.

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

BACKGROUND

Phototherapy (PT) is widely used to prevent and treat severe hyperbilirubinemia and its associated risks for both acute and chronic bilirubin encephalopathy. Intensive PT, recommended for inpatient treatment of hyperbilirubinemia in term and near-term infants, is defined as having a spectral irradiance of ≥30 μW/cm2/nm.

OBJECTIVES

We aimed to assess local PT practices by measuring the irradiance of PT devices in local neonatal intensive care units and newborn nurseries.

METHODS

The irradiance footprint, including maximum irradiance at the center of the footprint, of 39 PT devices in 7 area hospitals was measured according to current practice in these facilities.

RESULTS

The mean ± SD (range) footprint irradiance was 20.7 ± 5.8 (8.8-29.4) μW/cm2/nm. The mean ± SD maximum irradiance at the footprint center for all devices at a mean clinically used treatment distance of 33.1 ± 9.3 (25.5-60.0) cm was 27.8 ± 7.0 (14.7-42.0) μW/cm2/nm. Sixty-two percent of the devices did not meet the minimum recommended spectral irradiance for intensive PT. For the sites without irradiance-based protocols, the maximum irradiance of the devices (n = 33) at the treatment distances was 25.8 ± 6.1 μW/cm2/nm.

CONCLUSIONS

Despite established PT guidelines, local protocols and practices vary. Based on an assessment of 7 local hospitals, intensive PT was suboptimal for 62% of devices. Straightforward changes, such as decreasing the distance between an infant and the light source and establishing a consistent irradiance-based protocol, could substantially improve the quality of the intervention.

Irradiance levels of phototherapy devices: a national study in Dutch neonatal intensive care units

OBJECTIVE

The objective of this study is to determine whether irradiance levels of phototherapy (PT) devices in Dutch neonatal intensive care units (NICUs) increased between 2008 and 2013.

STUDY DESIGN

Irradiance of all types of PT devices, used in combination with incubators, was measured with a Dale 40 Radiometer (Fluke Biomedical, Everett, WA, USA) in all 10 Dutch NICUs.

RESULTS

Irradiance increased in seven NICUs. Median (range) irradiance increased from 9.7 (4.3-32.6) to 16.4 (6.8-41) μW cm^-2 nm^-1 for 24 overhead devices (P=0.004) and from 6.8 (0.8-15.6) to 22.3 (1.1-36.3) μW cm^-2 nm^-1 for 12 underneath devices (P=0.014). Five light-emitting diode (LED)-based devices were used in 2013 and one in 2008. The mean distance between overhead PT device and infant decreased by ~9 cm (P<0.001). Significantly more devices delivered minimal (10 μW cm^-2 nm^-1) recommended irradiance levels (80 vs ~45%; P=0.002).

CONCLUSION

Irradiance of PT devices still varies, but has markedly improved since 2008 due to shorter distances between PT device and infant, and introduction of better performing LED-based devices.

Heating of Newborn Infants due to Blue Light-Emitting Diode Fibreoptic Phototherapy Pads

BACKGROUND

Surface temperatures of fibreoptic phototherapy pads using a high intensity blue light-emitting diode (LED) light source have not been studied.

OBJECTIVES

The aim of this study was to measure the temperature of LED fibreoptic phototherapy pads during phototherapy in a bench-top study, and to determine temperature effects on babies during phototherapy.

METHODS

A commercially available LED fibreoptic phototherapy system was tested. In a bench-top setting, pad surface temperatures were measured before, during and after a 12-h period of phototherapy (10 different LED light box-pad combinations). A prospective, cohort study of well babies at >34 weeks' gestation receiving phototherapy was then conducted to determine changes in pad and body temperatures during a 90-min phototherapy period.

RESULTS

In the bench-top study, the mean (95% CI) pad temperature was 21.8°C (21.5-22.1) before lights, 27.0°C (26.5-27.5) after 12 h of lights, and 22.1°C (21.9-22.4) 8 h after turning off the lights (F = 366.1, p < 0.0005). The magnitude of change in pad temperature with phototherapy was linearly correlated with irradiance (r = 0.89, p < 0.0005). The pad plastic covering absorbed 13% of blue light from fibres. In the clinical study, the warmest pad temperature during phototherapy was 38.9°C. Axillary temperature increased by a mean (95% CI) of 0.3°C (0.1-0.5), p < 0.019, and exceeded 37.5°C in 4 babies.

CONCLUSIONS

LED fibreoptic phototherapy pads are heated by high-intensity blue light. The thermal environment and temperature of babies should be monitored closely during LED fibreoptic phototherapy. A temperature probe placed between the skin and the pad will not accurately reflect the core temperature during fibreoptic phototherapy.

A Pharmacologic View of Phototherapy

A pharmacologic view of phototherapy for neonatal jaundice is presented. By considering the photons of therapy light as molecules of a drug, this view connects therapeutic efficacy with photon wavelength, photon dose, dose rate and regimen, efficiency of photon absorption by bilirubin, quantum yields of photoproducts, and their metabolic courses. Based on this view, recommendations to ultimately improve efficacy and safety are presented. Special attention is given to phototherapy regimens for low gestational age, low birthweight infants.

Biology of Bilirubin Photoisomers

Phototherapy is the main treatment for neonatal hyperbilirubinemia. In acute treatment of extreme hyperbilirubinemia, intensive phototherapy may have a role in 'detoxifying' the bilirubin molecule to more polar photoisomers, which should be less prone to crossing the blood-brain barrier, providing a 'brain-sparing' effect. This article reviews the biology of bilirubin isomers. Although there is evidence supporting the lower toxicity of bilirubin photoisomers, there are studies showing the opposite. There are methodologic weaknesses in most studies and better-designed experiments are needed. In an infant acutely threatened by bilirubin-induced brain damage, intensified phototherapy should be used expediently and aggressively.

Body temperature changes of newborns under fluorescent versus LED phototherapy

OBJECTIVE

To determine changes in body temperature (BT) of hyperbilirubinemic newborns under conventional phototherapy with fluorescent lamps and light emitting diodes (LED) at different irradiances.

METHODS

Otherwise healthy newborn infants >34 wk gestational age (GA) hospitalized for indirect hyperbilirubinemia, requiring phototherapy in the first 10 d of life were enrolled. Infants who received conventional phototherapy with fluorescent lamps (10-15 μW/cm(2)/nm irradiance) were defined as group 1, LED phototherapy of 26-60 μW/cm(2)/nm irradiance as group 2, and LED phototherapy of 60-120 μW/cm(2)/nm irradiance as group 3. Primary outcome measure was mean BT which was defined as arithmetical mean of axillary BT measured at 2 h intervals during the first day of phototherapy.

RESULTS

Thirty patients were enroled in each group. Mean birth weight and GA of the total cohort was 2800 ± 530 g and 36.6 ± 2 wk, respectively. Baseline demographic variables and serum total bilirubin levels were similar among groups. Mean BT was 36.7 ± 0.1 °C in group 1, 36.6 ± 0.2 °C in group 2, 37.7 ± 0.2 °C in group 3. Mean BT was higher in group 3 compared to group 1 (p < 0.001) and group 2 (p < 0.001). Group 1 and group 2 had similar mean BT measurements (p = 0.09). During phototherapy all the patients in group 3 had at least one BT measurement ≥ 37.5 °C and 77 % had BT ≥ 38 °C. Only one patient in group 2 had BT ≥ 37.5 °C which was also ≥ 38 °C. During phototherapy all BT measurements were <37.5 °C in group 1.

CONCLUSIONS

LED phototherapy of ≥ 60 μW/cm(2)/nm intensity significantly increases BT in hyperbilirubinemic newborns.