Efficacy of "high-intensity" blue-light and "standard" daylight phototherapy for non-haemolytic hyperbilirubinaemia

Therapeutic effect of Agaricus brasiliensis on phenylhydrazine-induced neonatal jaundice in rats

The present study was designed to investigate the effect of Agaricus brasiliensis extract (ABE) on phenylhydrazine-induced neonatal jaundice in rats. Administration of ABE dose-dependently reduced the elevated bilirubin level induced by phenylhydrazine. It can be somewhat supported from the results of in vitro bilirubin degradation experiment. ABE treatment also reduced the total antioxidant status (TAOS), cascade O₂⁻/SOD, level of NF-κB protein, and adrenomedullin (AM). Overall, the results of this study demonstrated that Agaricus brasiliensis extract may be beneficial to reducing bilirubin level without causing hepatotoxicity in neonatal jaundice.

Bilirubin rebound after intensive phototherapy for neonatal jaundice

This study was conducted to determine the incidence and magnitude of post-phototherapy bilirubin rebound in neonates. Subjects included inborn neonates needing phototherapy for hyperbilirubinemia. Standard guidelines were used to start and stop phototherapy. Rebound bilirubin was measured 24+/-6 h after stopping phototherapy. Significant bilirubin rebound (SBR) was defined as post-phototherapy bilirubin level needing reinstitution of phototherapy. Among 245 neonates with hyperbilirubinemia, post-phototherapy bilirubin estimation was done in 232 neonates. A total of 17 (7.3%) neonates developed SBR. In neonates with SBR, bilirubin increased by 2.3 mg/dL (95% CI 1.6-3.0) after stopping phototherapy. Risk factors for SBR included birth at >35 weeks of gestation (RR 4.3, 95% CI 1.5-12.0), birthweight <2000 g (RR 3.2, 95% CI 1.0-10.3) and onset of jaundice at >60 h of age (RR 3.3, 95% CI 1.2-9.0). Post-phototherapy discharge and follow-up planning should take into account these risk factors.

Antioxidant status in neonatal jaundice before and after phototherapy

Phototherapy has been related to increased oxidative stress and lipid peroxidation. In the present study, thirty full term jaundiced neonates with appropriate weight were analyzed before and after completion of phototherapy for malondialdehyde (MDA), reduced glutathione (GSH), total thiols, vitamin C and superoxide dismutase (SOD) levels in hemolysate and albumin levels in plasma. These parameters were analyzed in cord blood samples of 20 healthy neonates as control. It was observed that levels of MDA were elevated significantly (p<0.001) in patients as compared to controls and that the levels increased significantly after phototherapy (p<0.001). Levels of SOD were also found to be increased significantly as compared to controls and the levels rose after phototherapy (p<0.001). On the other hand, the levels of non-enzymatic antioxidants such as GSH, total thiols and vitamin C were significantly low (p<0.001) as compared to controls and the levels decreased significantly after phototherapy (p<0.001). The plasma albumin levels also were found to be decreased significantly after phototherapy (p<0.01). Therefore, phototherapy increases oxidative stress and should be used with care.

Post-phototherapy neonatal bilirubin rebound: a potential cause of significant hyperbilirubinaemia

AIM

To determine the incidence of post-phototherapy neonatal plasma total bilirubin (PTB) rebound.

METHODS

A prospective clinical survey was performed on 226 term and near-term neonates treated with phototherapy in the well baby nursery of the Shaare Zedek Medical Center from January 2001 to September 2002. Neonates were tested for PTB 24 hours (between 12 and 36 hours) after discontinuation of phototherapy, with additional testing as clinically indicated. The main outcome measure, significant bilirubin rebound, was defined as a post-phototherapy PTB > or =256 micromol/l. Phototherapy was not reinstituted in all cases of rebound, but rather according to clinical indications.

RESULTS

A total of 30 (13.3%) neonates developed significant rebound (mean (SD) PTB 287 (27) micromol/l, upper range 351 micromol/l). Twenty two of these (73%) were retreated with phototherapy at mean PTB 296 (29) micromol/l. Multiple logistic regression analysis showed significant risk for aetiological risk factors including positive direct Coombs test (odds ratio 2.44, 95% CI 1.25 to 4.74) and gestational age <37 weeks (odds ratio 3.21, 95% CI 1.29 to 7.96). A greater number of neonates rebounded among those in whom phototherapy was commenced < or =72 hours (26/152, 17%) compared with >72 hours (4/74, 5.4%) (odds ratio 3.61, 95% CI 1.21 to 10.77).

CONCLUSION

Post-phototherapy neonatal bilirubin rebound to clinically significant levels may occur, especially in cases of prematurity, direct Coombs test positivity, and those treated < or =72 hours. These risk factors should be taken into account when planning post-phototherapy follow up.

The importance of irradiance and area in neonatal phototherapy

BACKGROUND

Despite a long period of development, there are still considerable variations in the spectral output, the levels of irradiance, and irradiated area provided by commercial phototherapy systems. These variations depend on the types and output of the lamps used to produce the phototherapy, along with the design of the systems, and principally on whether the phototherapy is provided from overhead or underneath.

OBJECTIVE

To see whether commercially available phototherapy systems produce sufficient irradiance over the surface area of the neonate.

METHODS

Surface plots of the output irradiance were made on a number of systems and used to calculate the effective irradiance on the surface of a premature or term baby, using mapped outlines.

RESULTS

A 10-fold difference in peak central irradiances was found between the systems tested, with a fourfold to fivefold difference in effective irradiance to the baby surfaces. Although work published over 20 years ago showed that levels of irradiance should reach 2 mW/cm2 to achieve optimal effectiveness, some of the commercial systems tested do not appear to achieve this level.

CONCLUSION

Purchasers of neonatal phototherapy systems need to take into account whether the systems will produce sufficient irradiance over the area to ensure maximal effect, to keep the treatment time to a minimum.

In vitro and in vivo efficacy of new blue light emitting diode phototherapy compared to conventional halogen quartz phototherapy for neonatal jaundice

High intensity light emitting diodes (LEDs) are being studied as possible light sources for the phototherapy of neonatal jaundice, as they can emit high intensity light of narrow wavelength band in the blue region of the visible light spectrum corresponding to the spectrum of maximal bilirubin absorption. We developed a prototype blue gallium nitride LED phototherapy unit with high intensity, and compared its efficacy to commercially used halogen quartz phototherapy device by measuring both in vitro and in vivo bilirubin photodegradation. The prototype device with two focused arrays, each with 500 blue LEDs, generated greater irradiance than the conventional device tested. The LED device showed a significantly higher efficacy of bilirubin photodegradation than the conventional phototherapy in both in vitro experiment using microhematocrit tubes (44+/-7% vs. 35+/-2%) and in vivo experiment using Gunn rats (30+/-9% vs. 16+/-8%). We conclude that high intensity blue LED device was much more effective than conventional phototherapy of both in vitro and in vivo bilirubin photodegradation. Further studies will be necessary to prove its clinical efficacy.

Randomized controlled trial of oral versus intravenous fluid supplementation on serum bilirubin level during phototherapy of term infants with severe hyperbilirubinaemia

OBJECTIVE

To compare the rates of decrease in serum bilirubin levels in severely jaundiced healthy term infants given oral or intravenous fluid supplementation during phototherapy.

METHODS

A randomized controlled study was carried out in the neonatal intensive care unit (NICU) of Hospital Universiti Kebangsaan Malaysia over a 12-month period. Fifty-four healthy term infants with severe hyperbilirubinemia were randomized to receive either solely enteral feeds (n = 27) or both enteral and intravenous (n = 27) fluid during phototherapy.

RESULTS

There were no significant differences in the mean birthweight, mean gestational age, ethnic distribution, gender distribution, modes of delivery and types of feeding between the two groups. Similarly, there was no significant difference in the mean indirect serum bilirubin (iSB) level at the time of admission to the NICU between the enteral (359 +/- 69 micromol/L [mean +/- SD]) and intravenous group (372 +/- 59 micromol/L; P = 0.4). The mean rates of decrease in iSB during the first 4 h of phototherapy were also not significantly different between the enteral group (10.4 +/- 4.9 micromol/L per h) and intravenous group (11.2 +/- 7.4 micromol/L per h; P = 0.6). There was no significant difference in the proportion of infants requiring exchange transfusion (P = 0.3) nor in the median duration of hospitalization (P = 0.7) between the two groups. No infant developed vomiting or abdominal distension during the study period.

CONCLUSION

Severely jaundiced healthy term infants had similar rates of decrease in iSB levels during the first 4 h of intensive phototherapy, irrespective of whether they received oral or intravenous fluid supplementation. However, using the oral route avoided the need for intravenous cannulae and their attendant complications.

Phototherapy--traditional and nontraditional

An observation by an English nurse in 1956 led to the discovery that visible light could lower serum bilirubin levels in newborn infants, and subsequent research showed how photons of light energy are absorbed by the bilirubin molecule converting it into isomers that are readily excreted by the liver and the kidney. Understanding the dose-response effect and other factors that influence the way light works to lower bilirubin levels has led to the effective use of phototherapy and has eliminated the need for exchange transfusion in almost all jaundiced infants.

Kangaroo mother care during phototherapy: effect on bilirubin profile

PURPOSE

To determine the safety and efficacy of allowing kangaroo mother care (KMC) one hour per day during the course of phototherapy using a fiberoptic phototherapy panel.

SAMPLE

Thirty premature infants, 30-35 weeks gestation, <2,500 gm, who required phototherapy. Infants were randomized into three groups: (1) infants who received traditional bank or spotlight phototherapy 24 hours per day, (2) infants who received traditional phototherapy 23 hours per day and for the 24th hour lay prone on a fiberoptic phototherapy panel, and (3) infants who received traditional phototherapy 23 hours per day and for the 24th hour were given KMC with a fiberoptic phototherapy panel held against their back.

OUTCOME VARIABLES

Nonparametric statistics were used for between-group comparisons on number of days of phototherapy, daily bilirubin decrement, and bilirubin profiles over the course of phototherapy.

RESULTS

Groups did not differ in the number of days of phototherapy or in daily mean bilirubin decrement. The bilirubin profile for the KMC group showed a more shallow descent than did the profiles for the other groups, but a significant difference in decline was present only on day 4 of treatment (p = .05).

CONCLUSION

This pilot work suggests that KMC using a fiberoptic panel during phototherapy may be safe, but further study is needed.

An evaluation of the characteristics and performance of neonatal phototherapy equipment

This paper reviews the current state of knowledge and practice in neonatal phototherapy, and assesses methods of evaluating the characteristics and performance of different equipment. Artificial lighting (usually fluorescent) has been used for the past 30 years in the treatment of neonatal jaundice. Widely differing light outputs and spectra are used, making comparison and evaluation difficult for clinicians. Manufacturers of neonatal phototherapy equipment have no standard for assessing the performance of their equipment, and information that is supplied is at best confusing or deceptive to the users. Best practice is usually based on empirical data from equipment in use, but there is wide agreement that present phototherapy is sub-optimal, i.e. does not achieve maximum rate of bilirubin clearance for minimum therapeutic dose. Several studies in the last ten years have emphasized the importance of both the wavelength and intensity of light for optimal phototherapy. These are discussed and a technique is proposed for normalizing the output of different systems to make comparison easier and to enable optimal treatments to be designed.

Acute management of extreme neonatal jaundice--the potential benefits of intensified phototherapy and interruption of enterohepatic bilirubin circulation

Increasing numbers of neonates are being admitted to hospital because of extreme jaundice. Phototherapy should be very effective in such infants, because the efficacy of phototherapy is proportional to the concentration of bilirubin in the skin. Here, I report on four infants who were admitted for indirect serum bilirubin levels of >500 micromol/l (>>30 mg/dl). In one of them, unrecognized Rhesus immunization was the main cause of hyperbilirubinemia, while in the other three increased enterohepatic circulation of bilirubin was thought to be an important contributory factor. In all four infants phototherapy (11-14 microW/cm2/nm) with whole body exposure plus ad lib feeding with milk were initiated immediately upon admission to the nursery. After 2h serum bilirubin values were reduced by 170-185 micromol/l (10-11 mg/dl) in the first three infants, while in the fourth infant a reduction of 195 micromol/l (11.3 mg/dl) was seen in the 5 h interval between the first and second bilirubin measurement. This experience suggests that in some infants with extreme jaundice, intensified phototherapy plus feeding with milk may be very effective in reducing serum bilirubin levels. Even if an exchange transfusion is performed, using this strategy in the waiting period may be beneficial, as both the rapid reduction in serum bilirubin levels as well as the conversion of significant amounts of bilirubin into water-soluble isomers may reduce the risk of neurotoxicity.

Efficacy of bidirectional fiber-optic phototherapy for neonatal hyperbilirubinemia

OBJECTIVE

To evaluate the efficacy of fiber-optic phototherapy using the standard Ohmeda Biliblanket, a large version, double standard Biliblankets, and conventional phototherapy using daylight fluorescent lamps in full-term, healthy infants with nonhemolytic hyperbilirubinemia.

METHODS

Full-term, healthy infants with nonhemolytic hyperbilirubinemia (bilirubin concentration, >255 micromol/L or 222 micromol/L at <48 hours of age) were allocated randomly to one of four modes of phototherapy: standard fiber-optic mat (Ohmeda Biliblanket), a large version, double standard Biliblankets, and conventional phototherapy. Bilirubin levels were monitored every 12 hours. Exposure was stopped when bilirubin levels were less than 185 micromol/L, the minimum duration being 24 hours.

RESULTS

A total of 171 infants were studied; 42 were exposed to standard fiber-optic phototherapy, 43 to large fiber-optic phototherapy, 42 to double-fiber-optic phototherapy, and 44 to conventional phototherapy. Durations of exposure were 87.05 +/- 6.09 (SEM), 82.57 +/- 5.84, 64.85 +/- 5.43, and 62.61 +/- 3.74 hours, respectively; the 24-hour decline rates were 10.26% +/- 1.84%, 14. 50% +/- 1.53%, 21.82% +/- 1.71%, and 19.00% +/- 1.65%, respectively; the overall decline rates over the whole exposure period were 0.47% +/- 0.03%, 0.52% +/- 0.04%, 0.71% +/- 0.05%, and 0.75% +/- 0.04% per hour, respectively. The efficacy of double-fiber-optic phototherapy and conventional phototherapy was similar and significantly better than that of the large fiber-optic mat and the standard fiber-optic mat in duration, 24-hour decline rate, and overall decline rate. The large mat was slightly better than the standard-size mat with regard to 24-hour decline rate and overall decline rate, but this difference was not significant. Failure of phototherapy occurred only in the large fiber-optic mat group (3 of 43) and the standard fiber-optic mat group (4 of 42); none occurred in the other two groups, but differences not statistically significant. The nursing personnel were more comfortable with single fiber-optic phototherapy, which caused no initial disturbance to the swaddled infants as did conventional phototherapy, but found double-fiber-optic phototherapy difficult to use.

CONCLUSION

For efficacy of fiber-optic phototherapy in full-term infants to be comparable to that of our conventional phototherapy, the light dose of the standard mats needs to be doubled.

Effect of phototherapy on thyroid stimulatory hormone and free thyroxine levels

OBJECTIVE

To study the effect of phototherapy for neonatal hyperbilirubinaemia on thyroid function as neonatal thyroid screening is sometimes performed during exposure to phototherapy.

METHODOLOGY

Infants with non-haemolytic hyperbilirubinaemia were sequentially allocated to fibre-optic phototherapy, conventional daylight phototherapy, or a combination of both. Bilirubin concentration was monitored 12 hourly by capillary blood sampling; venous blood was sampled for thyroid stimulating hormone (TSH) and free thyroxine (fT4) determinations, at start of exposure, at 24 h, end of exposure and 1 day later. Comparable unexposed infants served as controls.

RESULTS

All 123 study infants and 25 controls remained well during the study. Bilirubin levels declined during phototherapy, being most rapid in the combination group. The TSH and fT4 values at start of exposure were 3.86 +/- 0.41 mU/L (mean +/- SEM) and 33.20 +/- 1.16 pmol/L, respectively, in the fibre-optic group, 3.62 +/- 0.38 mU/L and 37.22 +/- 1.76 pmol/L in the daylight group, and 4.40 +/- 0.48 mU/L and 29.91 +/- 1.13 pmol/L in the combined group, compared with 5.77 +/- 0.40 mU/L and 34.46 +/- 1.68 pmol/L in the control group. The TSH and fT4 values declined with increasing age in the phototherapy and control groups with end of exposure values of 2.90 +/- 0.28 mU/L and 27.71 +/- 0.71 pmol/L, 2.77 +/- 0.31 mU/L and 33.52 +/- 1.22 pmol/L, and 3.44 +/- 0.30 mU/L and 27.54 +/- 0.88 pmol/L, respectively, compared with 4.21 +/- 0.61 mU/L and 27.19 +/- 2.33 pmol/L (at 72 h) in the control group. The pattern of TSH and fT4 decline in the exposed and control groups was similar, being related to increasing age.

CONCLUSIONS

The validity of neonatal thyroid screening is not affected by fibre-optic or conventional phototherapy or by both combined.

Improvements in long term phototherapy for patients with Crigler-Najjar syndrome type I

Patients with Crigler-Najjar syndrome Type I are being treated with long-term blue-light phototherapy into childhood, adolescence and beyond. Phototherapy systems adapted from sunbed-type bases fitted with blue-emitting fluorescent tubes have been described. These systems provided higher irradiances and improved patient compliance compared with overhead therapy systems used in neonatal phototherapy. The acrylic bases of such units are, however, not designed to provide adequate levels of comfort for prolonged treatment in the long term. Previous work has shown that layer(s) of transparent 'bubble-wrap' can be used to address this problem, although the material absorbs light and provides lower levels of comfort for older or larger patients. We have used designs of transparent plastic lilos that provide better cushioning, although tend to puncture, and share with bubble-wrap a low porosity leading to patient discomfort. We have investigated the use of standard mesh and high-transmission fabrics stretched over an adjustable-tension frame. This method in particular combines a high degree of comfort with a clinically effective blue-light irradiance level, and hence appears to provide a satisfactory method of phototherapy delivery. The development of higher transmission materials offers further potential for improvement.

Fibreoptic phototherapy in the management of jaundice in low birthweight neonates

A fibreoptic phototherapy device has been compared with conventional white and special blue fluorescent phototherapy lamps to evaluate its efficacy in lowering serum bilirubin levels in low-birthweight neonates. Fibreoptic phototherapy was found to be as effective as white light and less effective than blue light, as assessed by (i) the bilirubin concentration after 24 h of phototherapy and at the end of phototherapy, (ii) the duration of phototherapy, (iii) the percentage daily decline rate and (iv) the overall percentage decline rate (p < 0.05). There were no failures of phototherapy and the need for re-exposure was low (4.7% of the total sample), with no difference between groups. The fibreoptic approach represents a promising way to aggregate synergically the most recent optical technologies and develop a modern, efficient and caring phototherapy system for low-birthweight infants.

Phototherapy for neonatal jaundice

Exchange transfusion for severe neonatal jaundice is a tedious and expensive procedure with high morbidity and mortality rates, and is followed by a prompt and marked bilirubin rebound. It has largely been replaced by phototherapy, which though more gradual in its effect results in a prolonged reduction of the bilirubin concentration. Its efficacy is influenced by the gestational age, birthweight and postnatal age of the infant, the aetiology of the jaundice, and the spectral emission and intensity (dose) of the light; its dose-response relationship enables it, at the optimal dose, to control very severe jaundice or a rapidly rising bilirubin concentration, including severe haemolysis. Its relative freedom from complications together with its non-invasive nature, ease of usage and convenience has resulted in widespread acceptance in virtually all neonatal units.

Phototherapy for neonatal jaundice in infants with cephalhematomas

The efficacy of phototherapy in a group of infants with nonhemolytic hyperbilirubinemia and no cephalhematomas was compared with a second group of infants with large cephalhematomas (> 7 cm across), but similar in all other aspects. The cephalhematoma group demonstrated significantly lower hemoglobin (Hb) and hematocrit (hct) values (P < .0001, P < .002 respectively) than the standard group, even after the latter group had been adjusted by stratification (P < .0001, P < .005) such that the starting bilirubin concentration, birth weight, and gestational age were highly comparable to the cephalhematoma group. The bilirubin concentrations of the cephalhematoma, original, and adjusted groups were 277.8 +/- 5.8 mumol/L (16.24 +/- 0.03 mg/dL), [mean +/- sem], 265.2 +/- 0.5 mumol/L (15.50 +/- 0.03 mg/dL), and 275.2 +/- 0.9 mumol/L (16.09 +/- 0.05 mg/dL), respectively. The postnatal age at the start of phototherapy in the cephalhematoma group was comparable with that of the standard group before and after adjustment. Phototherapy was equally effective in the cephalhematoma and standard (original and adjusted) groups of infants, in terms of duration, 24-hr decline, and overall decline/hr for the duration of exposure. The proportionate 24-hr decline was 24.02 +/- 1.90% vs 20.99 +/- 0.23% and 22.61 +/- 0.48% and overall decline/hr was 0.83 +/- 0.06% vs 0.74 +/- 0.01% and 0.78 +/- 0.01%. We conclude that the sequestrated blood in the cephalhematomas did not significantly interfere with the efficacy of phototherapy.

Comparison of the efficacy of fiberoptic and conventional phototherapy for neonatal hyperbilirubinemia

A comparative evaluation of the efficacy of fiberoptic phototherapy using the Ohmeda Billiblanket fiberoptic device, conventional phototherapy using daylight fluorescent lamps, and a combination of the two forms of phototherapy was made in 165 term healthy infants and 105 preterm infants with hyperbilirubinemia. In the term infants, the 24-hour decline rate for fiberoptic phototherapy was 9.2% +/- 1.6% (mean +/- SEM) versus 21.5% +/- 1.8% for daylight phototherapy (p < 0.01), and the overall decline rate was 0.49% +/- 0.03%/hr versus 0.70% +/- 0.04%/hr (p < 0.001). Combination phototherapy, with a 24-hour decline rate of 29.9% +/- 1.0% and an overall decline rate of 0.97% %/- 0.04%/hr, was significantly better than daylight phototherapy in both respects (p < 0.01 and < 0.01, respectively). The duration of exposure for fiberoptic phototherapy was significantly longer than that for daylight phototherapy, which in turn was significantly longer than that for combination phototherapy. Response to exposure in the preterm infants was significantly better than that in the term infants with the respective types of phototherapy. The nursing personnel unanimously felt more comfortable with fiberoptic phototherapy, which did not disturb the swaddled infants as much as conventional phototherapy. The parents also felt more reassured. Fiberoptic phototherapy proved adequate in controlling hyperbilirubinemia in preterm infants; in term infants, failures often occurred. Combination phototherapy can be recommended for severe or rapidly increasing jaundice in preterm infants, but its efficacy in term infants is uncertain.