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

Clinical study to determine the predictability of significant rebound hyperbilirubinemia in neonates after phototherapy and conditions likely to be associated with it: Prospective observational study in a teaching hospital in Eastern India

Aim

Neonatal hyperbilirubinemia is defined as yellowish discoloration of the skin, conjunctive, and sclera from the elevated serum or plasma bilirubin in the newborn. The standard of care for the management of neonatal hyperbilirubinemia is phototherapy to prevent long-term neurological sequelae. The aim of this study was to ascertain the predictability of significant rebound hyperbilirubinemia (SRH) in neonates after phototherapy and the factors associated with it.

Materials and Methods

Neonates ≥ 35 weeks of gestation, who received treatment for hyperbilirubinemia and admitted in our hospital from 15th of March 2019 to 15th of September 2020 were enrolled after taking parental consent. SRH was defined as bilirubin levels crossing the treatment threshold within 72 hours of phototherapy termination. Logistic regression analysis was used to identify the predictability of SRH.

Results

Out of 400 neonates treated with phototherapy, 10% developed SRH. Prematurity (Gestational age < 37 weeks), low birth weight (Birth weight < 2000 gram), ABO and Rh incompatibility, Glucose-6-phophate dehydrogenase deficiency (G6PD) deficiency, sepsis, and longer duration of primary phototherapy were found to be significantly associated with rebound hyperbilirubinemia. The probability of SRH increases for all American Academy of Paediatrics (AAP) risk categories as the gestational age decreases and total serum bilirubin at the stoppage of phototherapy increases.

Conclusions

The presence of risk factors should be taken into account while planning discharge and follow-up of neonates admitted for neonatal hyperbilirubinemia to prevent long-term complication of bilirubin neurotoxicity.

Risk Factors and Predictors of Rebound Hyperbilirubinemia in a Term and Late-Preterm Infant with Hemolysis

OBJECTIVE

This study aimed to assess the incidence and predictors of rebound in term and late-preterm infants with hemolytic hyperbilirubinemia postphototherapy.

STUDY DESIGN

A 4-year retrospective data analysis of neonates with hemolytic indirect hyperbilirubinemia admitted to the neonatal intensive care unit (NICU) of Medina Maternity and Children's Hospital was conducted. Bilirubin rebound was defined as the return of total serum bilirubin (TSB) to phototherapy threshold within 72 hours of postphototherapy.

RESULTS

Of 386 identified neonates; 44 (11%) experienced rebound. Neonates in the rebound group demonstrated significantly higher levels of peak TSB, TSB at discontinuation of phototherapy, and lower value of relative TSB (difference between TSB at phototherapy termination and the American Academy of Pediatrics [AAP] threshold for phototherapy at concurrent age) compared with nonrebound group (p-value: <0.001, <0.001, and 0.007, respectively). Lower value of relative TSB at stoppage of phototherapy was the single independent predictor for rebound hyperbilirubinemia by mutivariate regression (p < 0.001). A cut-off value for relative TSB at stoppage of phototherapy of 190 µmol/L had 98% sensitivity and 32% specificity to predict rebound hyperbilirubinemia.

CONCLUSION

Relative TSB at phototherapy termination is the best predictor for postphototherapy rebound hyperbilirubinemia in neonates with hemolytic etiology.

KEY POINTS

· 11% of neonates showed postphototherapy rebound.. · The relative TSB at stoppage of phototherapy is the best predictor for rebound hyperbilirubinemia.. · The first cohort to assess rebound in neonates with hemolysis..

Validation of published rebound hyperbilirubinemia risk prediction scores during birth hospitalization after initial phototherapy: a retrospective chart review

BACKGROUND

Hyperbilirubinemia commonly affects newborns and may lead to neurotoxicity if untreated. Neonates can experience rebound hyperbilirubinemia (RHB), defined as elevated bilirubin levels requiring re-initiation of treatment. Although studies have formulated risk prediction scores, they lack external validation. In this study, we examine the discrimination and calibration performance of risk prediction scores for RHB, to provide external validation.

METHODS

We reviewed charts of neonates born ≥35 weeks of gestation between January 2015 and December 2019 receiving phototherapy at birth hospitalization. We plotted predicted probabilities against observed outcome proportions to assess model calibration and evaluated discrimination using area under the receiver operating characteristic (AUROC) curves. Odds ratios (ORs) were estimated to evaluate variables associated with RHB.

RESULTS

Of the 271 infants identified, 24% developed RHB. Two- and three-variable prediction scores had lower discrimination in our cohort with AUROC of 0.662 (95% CI 0.590-0.735) and 0.691 (95% CI, 0.619-0.763) compared to 0.876 (95% CI 0.854-0.899) and 0.881 (95% CI 0.859-0.903), respectively, in the published studies. Estimated ORs confirm associations between RHB and variables included in prediction scores.

CONCLUSIONS

Current prediction models for RHB have unclear clinical utility in our patient population. Additional studies are required to further validate these scores.

IMPACT

Describes performance characteristics of two- and three-variable risk prediction scores that lack external validation beyond the initial study cohort. Our findings suggest unclear clinical utility in our clinical population of neonates during birth hospitalization, with lower performance of these prediction scores than observed in the derivation cohort. Odds ratios estimated by logistic regression in our study cohort provide further evidence that variables in published risk prediction scores are associated with rebound hyperbilirubinemia. Further studies are required to externally validate these risk prediction scores and to assess their generalizability.

The development and validation of a predictive model for neonatal phototherapy outcome using admission indicators

Delayed exchange transfusion therapy (ETT) after phototherapy failure for newborns with severe hyperbilirubinemia could lead to serious complications such as bilirubin encephalopathy (BE). In this current manuscript we developed and validated a model using admission data for early prediction of phototherapy failure. We retrospectively examined the medical records of 292 newborns with severe hyperbilirubinemia as the training cohort and another 52 neonates as the validation cohort. Logistic regression modeling was employed to create a predictive model with seven significant admission indicators, i.e., age, past medical history, presence of hemolysis, hemoglobin, neutrophil proportion, albumin (ALB), and total serum bilirubin (TSB). To validate the model, two other models with conventional indicators were created, one incorporating the admission indicators and phototherapy failure outcome and the other using TSB decrease after phototherapy failure as a variable and phototherapy outcome as an outcome indicator. The area under the curve (AUC) of the predictive model was 0.958 [95% confidence interval (CI): 0.924-0.993] and 0.961 (95% CI: 0.914-1.000) in the training and validation cohorts, respectively. Compared with the conventional models, the new model had better predictive power and greater value for clinical decision-making by providing a possibly earlier and more accurate prediction of phototherapy failure. More rapid clinical decision-making and interventions may potentially minimize occurrence of serious complications of severe neonatal hyperbilirubinemia.

Treatment practices and implementation of guidelines for hyperbilirubinemia and rebound hyperbilirubinemia

BACKGROUND

Hyperbilirubinemia (HB), defined as elevated total serum bilirubin (TSB) levels, commonly affects neonates and requires prompt treatment to prevent neurological complications. Up to 10%of neonates experience rebound hyperbilirubinemia (RHB), requiring re-initiation of treatment. Unfortunately, treatment guidelines lack practical recommendations surrounding subthreshold phototherapy, treatment termination, and RHB investigations. We examined local management practices for HB and RHB treatment in a well newborn nursery. As a secondary aim, we investigated the association between treatment practices and RHB rates.

METHODS

Retrospective chart review identified neonates treated for hyperbilirubinemia between January 2015 and December 2019 during their birth hospitalization at a tertiary care centre. Standardized data collection sheets were used to record treatment parameters.

RESULTS

Over the 5-year period, there were 9683 births and 305 (3.15%) neonates received phototherapy. Of the treated cases, 20-25%were subthreshold to practice guideline values. Upon treatment termination 25-55%of cases had TSB levels within 3 mg/dL, which may increase the risk of RHB. In our cohort, 20.3%of treated cases experienced one episode of RHB and 3.9%experienced two episodes of RHB. Although clinicians evaluated neonates for RHB 0-12 hours following treatment termination prior to discharge, many cases were identified in outpatient settings and required re-admission for phototherapy.

CONCLUSION

When managing HB and RHB, treatment practices such as when to terminate treatment in relation to threshold values, and timing of RHB investigations, are largely inconsistent amongst clinicians. Future studies are required to better understand the landscape of hyperbilirubinemia treatment beyond initiation of phototherapy.

Heme Catabolism and Bilirubin Production in Readmitted Jaundiced Newborns

We measured end-tidal CO levels in 50 jaundiced newborns readmitted for phototherapy at age 54-244 hours. The median end-tidal CO level was 1.55 ppm, suggesting that hemolysis is not the primary contributor to the hyperbilirubinemia in many readmitted newborns.

Predictive Models for Neonatal Follow-Up Serum Bilirubin: Model Development and Validation

Background

Hyperbilirubinemia affects many newborn infants and, if not treated appropriately, can lead to irreversible brain injury.

Objective

This study aims to develop predictive models of follow-up total serum bilirubin measurement and to compare their accuracy with that of clinician predictions.

Methods

Subjects were patients born between June 2015 and June 2019 at 4 hospitals in Massachusetts. The prediction target was a follow-up total serum bilirubin measurement obtained <72 hours after a previous measurement. Birth before versus after February 2019 was used to generate a training set (27,428 target measurements) and a held-out test set (3320 measurements), respectively. Multiple supervised learning models were trained. To further assess model performance, predictions on the held-out test set were also compared with corresponding predictions from clinicians.

Results

The best predictive accuracy on the held-out test set was obtained with the multilayer perceptron (ie, neural network, mean absolute error [MAE] 1.05 mg/dL) and Xgboost (MAE 1.04 mg/dL) models. A limited number of predictors were sufficient for constructing models with the best performance and avoiding overfitting: current bilirubin measurement, last rate of rise, proportion of time under phototherapy, time to next measurement, gestational age at birth, current age, and fractional weight change from birth. Clinicians made a total of 210 prospective predictions. The neural network model accuracy on this subset of predictions had an MAE of 1.06 mg/dL compared with clinician predictions with an MAE of 1.38 mg/dL (P<.0001). In babies born at 35 weeks of gestation or later, this approach was also applied to predict the binary outcome of subsequently exceeding consensus guidelines for phototherapy initiation and achieved an area under the receiver operator characteristic curve of 0.94 (95% CI 0.91 to 0.97).

Conclusions

This study developed predictive models for neonatal follow-up total serum bilirubin measurements that outperform clinicians. This may be the first report of models that predict specific bilirubin values, are not limited to near-term patients without risk factors, and take into account the effect of phototherapy.

Comparison of Purgative Manna Drop and Phototherapy with Phototherapy Treatment of Neonatal Jaundice: A Randomized Double-Blind Clinical Trial

Objectives

Herbal remedies such as purgative manna are used to treat neonatal jaundice. In this study Bilineaster drop (purgative manna) and phototherapy, and phototherapy treatment alone were compared by assessing phototherapy duration and number of days in hospital.

Methods

There were 150 consecutive term neonates with jaundice, weighting from 2,500 g to 4,000 g enrolled in this randomized double blind clinical trial. The neonates were randomly assigned to intervention and control groups. The control patients received only phototherapy and the intervention group underwent phototherapy treatment and purgative manna drop (5 drops per kg of body weight, 3 times a day). Direct and total measurements of bilirubin concentration in the serum were measured and the reduction in concentration of bilirubin was calculated.

Results

There were 28% of patients whose hospital duration following phototherapy was 2 days, for Bilineaster and phototherapy treatment this was 49.3% of patients. At 48 hours and 72 hours the reduction in the concentration of total bilirubin in the serum was statistically significantly different across groups (p < 0.05) but at 24 hours and 96 hours there were no significant differences between groups (p > 0.05). The reduction in direct bilirubin concentration in the serum was significantly different between groups at 72 hours and 96 hours (p > 0.001).

Conclusion

Purgative manna and phototherapy, can statistically significantly reduce total bilirubin concentration at 48 hours and 72 hours compared with phototherapy alone, and reduce the length of hospital stay for jaundiced neonates at 2 days compared with phototherapy treatment.

A Simpler Prediction Rule for Rebound Hyperbilirubinemia

OBJECTIVES

We previously reported a clinical prediction rule to estimate the probability of rebound hyperbilirubinemia using gestational age (GA), age at phototherapy initiation, and total serum bilirubin (TSB) relative to the treatment threshold at phototherapy termination. We investigated (1) how a simpler 2-variable model would perform and (2) the absolute rebound risk if phototherapy were stopped at 2 mg/dL below the threshold for treatment initiation.

METHODS

Subjects for this retrospective cohort study were infants born 2012-2014 at ≥35 weeks' gestation at 1 of 17 Kaiser Permanente hospitals who underwent inpatient phototherapy before age 14 days. TSB reaching the phototherapy threshold within 72 hours of phototherapy termination was considered rebound. We simplified by using the difference between the TSB level at the time of phototherapy termination and the treatment threshold at the time of phototherapy initiation as 1 predictor, and kept GA as the other predictor.

RESULTS

Of the 7048 infants treated with phototherapy, 4.6% had rebound hyperbilirubinemia. The area under the receiver operating characteristic curve was 0.876 (95% confidence interval, 0.854 to 0.899) for the 2-variable model versus 0.881 (95% confidence interval, 0.859 to 0.903) for the 3-variable model. The rebound probability after stopping phototherapy at 2 mg/dL below the starting threshold was 2.5% for infants ≥38 weeks' GA and 10.2% for infants <38 weeks' GA.

CONCLUSIONS

Rebound hyperbilirubinemia can be predicted by a simpler 2-variable model consisting of GA and the starting threshold-ending TSB difference. Infants <38 weeks' gestation may need longer phototherapy because of their higher rebound risk.

Identification of risk for neonatal haemolysis

AIM

To identify neonates at risk of haemolytic hyperbilirubinaemia through near-concurrent measurements of total serum/plasma bilirubin (TB) or transcutaneous bilirubin (TcB) and end-tidal breath carbon monoxide (CO), corrected for ambient CO (ETCOc), an index of bilirubin production and haemolysis.

METHODS

Paired TB/TcB (mg/dL) and ETCOc (ppm) measurements were obtained in newborns (n = 283) at 20 to <60 hours of age in five nurseries. TB/TcB values were assigned TB/TcB percentile risk values using the Bhutani hour-specific nomogram. In infants having two serial TB/TcB measurements (n = 76), TB rate of rise (ROR, mg/dL/h) was calculated.

RESULTS

For the entire cohort (n = 283), 67.1% and 32.9% had TB/TcB<75th and ≥75th percentile, respectively. TB/TcB (5.79 ± 1.84 vs 9.14 ± 2.25 mg/dL) and ETCOc (1.61 ± 0.45 vs 2.02 ± 1.35 ppm, p = 0.0002) were different between the groups. About 36.6% of infants with TB/TcB ≥75th percentile had ETCOc ≥ 2.0 ppm. In the subcohort of infants with serial TB/TcB measurements (n = 76), 44.7% and 55.3% had TB/TcB<75th and ≥75th percentile, respectively. TB/TcB (5.28 ± 1.97 vs 9.53 ± 2.78 mg/dL), ETCOc (1.72 ± 0.48 vs 2.38 ± 1.89 ppm, p = 0.05) and TB ROR (0.011 ± 0.440 vs 0.172 ± 0.471 mg/dL/h) were different between the groups.

CONCLUSION

The combined use of TB/TcB percentile risk assessments and ETCOc measurements can identify infants with haemolytic hyperbilirubinaemia. The addition of TB ROR can identify those infants with elimination disorders.

Incidence and risk factors of post-phototherapy neonatal rebound hyperbilirubinemia

BACKGROUND

To determine the incidence and risk factors of post-phototherapy rebound hyperbilirubinemia because data about bilirubin rebound in neonates are lacking and few studies have concerned this condition.

METHODS

A prospective observational study was conducted on 500 neonates with indirect hyperbilirubinemia who were treated according to standard guidelines. Total serum bilirubin (TSB) was measured at 24-36 h after phototherapy; significant bilirubin rebound (SBR) is considered as increasing TSB that needs reinstitution of phototherapy.

RESULTS

A total of 124 (24.9%) neonates developed SBR with TSB increased by 3.4 (2.4-11.2) mg/dL after stopping phototherapy. Multiple logistic regression model revealed the following significant risk factors for rebound: low birth weight (B = 1.3, P <  0.001, OR 3.5), suspected sepsis (B = 2.5, P <  0.001, OR 12.6), exposure to intensive phototherapy (B =  0.83, P =  0.03, OR 2.3), hemolysis (B =  1.2, P <  0.001, OR 3.1), high discharge bilirubin level (B =  0.3, P =  0.001, OR 1.3), and short duration of conventional phototherapy (B =  - 1.2, P <  0.001, OR 0.3).

CONCLUSIONS

SBR should be considered in neonates with hemolysis, low birth weight, suspected sepsis, short duration of conventional phototherapy, exposure to intensive phototherapy, and relatively high discharge TSB. These risk factors should be taken into account when planning post-phototherapy follow-up.

[Guidelines for prevention, detection and management of hyperbilirubinaemia in newborns of 35 or more weeks of gestation]

Hyperbilirubinaemia is one of the most frequent causes of hospital readmission during the first week of life. Its detection is still a big challenge, mainly due to the early discharge from the hospital that can be associated with a delay of the diagnosis. The identification of those newborns at risk of developing significant hyperbilirubinaemia is one of the main priorities in the public health care system. An approach to the management of newborn jaundice is presented in this article, following the recommendations based on the medical evidence and on the opinion of the Standards Committee of the Spanish Society of Neonatology.

A Clinical Prediction Rule for Rebound Hyperbilirubinemia Following Inpatient Phototherapy

OBJECTIVES

The American Academy of Pediatrics provides little guidance on when to discontinue phototherapy in newborns treated for hyperbilirubinemia. We sought to develop a prediction rule to estimate the probability of rebound hyperbilirubinemia after inpatient phototherapy.

METHODS

Subjects for this retrospective cohort study were infants born in 2012 to 2014 at ≥35 weeks' gestation at 16 Kaiser Permanente Northern California hospitals who received inpatient phototherapy before age 14 days. We defined rebound as the return of total serum bilirubin (TSB) to phototherapy threshold within 72 hours of phototherapy termination. We used stepwise logistic regression to select predictors of rebound hyperbilirubinemia and devised and validated a prediction score by using split sample validation.

RESULTS

Of the 7048 infants treated with inpatient phototherapy, 4.6% had rebound hyperbilirubinemia. Our prediction score consisted of 3 variables: gestational age <38 weeks (adjusted odds ratio [aOR] 4.7; 95% confidence interval [CI], 3.0-7.3), younger age at phototherapy initiation (aOR 0.51 per day; 95% CI, 0.38-0.68), and TSB relative to the treatment threshold at phototherapy termination (aOR 1.5 per mg/dL; 95% CI, 1.4-1.7). The model performed well with an area under the receiver operating characteristic curve of 0.89 (95% CI, 0.86-0.91) in the derivation data set and 0.88 (95% CI, 0.86-0.90) in the validation data set. Approximately 70% of infants had scores <20, which correspond to a <4% probability of rebound hyperbilirubinemia.

CONCLUSIONS

The risk of rebound hyperbilirubinemia can be quantified according to an infant's gestational age, age at phototherapy initiation, and TSB relative to the treatment threshold at phototherapy termination.

High-intensity light-emitting diode vs fluorescent tubes for intensive phototherapy in neonates

BACKGROUND

Special blue fluorescent tubes are recommended by the American Academy of Pediatrics (AAP) as the most effective light source for lowering serum bilirubin. A high-intensity light-emitting diode ('super LED') could render intensive phototherapy more effective than the above conventional methods. This study compared the efficacy and safety of a high-intensity light-emitting diode bed vs conventional intensive phototherapy with triple fluorescent tube units as a rescue treatment for severe unconjugated neonatal hyperbilirubinaemia.

METHOD

This was a randomised, prospective trial. Two hundred jaundiced neonates ≥ 35 weeks gestation who met the criteria for intensive phototherapy as per AAP guidelines were randomly assigned to be treated either with triple fluorescent tube units (group 1, n = 100) or a super LED bed (group 2, n = 100). The outcome was the avoidance of exchange transfusion by successful control of hyperbilirubinaemia.

RESULTS

Statistically significant higher success rates of intensive phototherapy were achieved among neonates treated with super LED (group 2) than in those treated conventionally (group 1) (87% vs 64%, P = 0.003). Significantly higher 'bilirubin decline' rates were reported in both haemolytic and non-haemolytic subgroups treated with the super LED bed compared with a similar sub-population in the conventionally treated group. Comparable numbers of neonates in both groups developed rebound jaundice (8% vs 10% of groups 1 and 2, respectively). Side-effects were mild in both groups, but higher rates of hyperthermia (12% vs 0%, P = 0.03), dehydration (8% vs 2%, P = 0.26) and skin rash (39% vs 1%, P = 0.002) were reported in the fluorescent tubes-treated group compared with the LED group.

CONCLUSIONS

Super LED is a safe rescue treatment for severe neonatal hyperbilirubinaemia, and its implementation may reduce the need for exchange transfusion.

The utility of inpatient rebound bilirubin levels in infants readmitted after birth hospitalization for hyperbilirubinemia

BACKGROUND AND OBJECTIVES

There are few data evaluating the role of inpatient rebound bilirubin levels in the management of infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. The goal of the present study was to evaluate the clinical utility of inpatient rebound bilirubin levels within this patient population.

METHODS

A retrospective cohort study was conducted of 226 infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. Data from 130 infants with rebound bilirubin levels drawn at a mean of 6.1±2.4 hours after discontinuation of phototherapy were compared with data from 96 infants without rebound bilirubin levels. The primary outcome was readmission to the hospital, and secondary outcomes included length of stay and discharge time. A subgroup analysis compared characteristics of children who required repeat phototherapy versus those who did not.

RESULTS

Overall, 5 of 130 patients from the rebound group were readmitted compared with 4 of 96 patients from the no-rebound group (P=.98). Length of stay was significantly longer for patients with rebound bilirubin levels (27.7 vs 23.2 hours; P=.001). Patients with bilirubin levels lowered to ≤14 mg/dL were less likely to receive repeat phototherapy than those with levels>14 mg/dL (2 of 129 vs 12 of 97; P=.001).

CONCLUSIONS

Early inpatient rebound bilirubin levels do not successfully predict which patients will require hospital readmission for repeat phototherapy. Children with bilirubin levels lowered to ≤14 mg/dL with phototherapy are unlikely to receive repeat phototherapy.

Italian guidelines for management and treatment of hyperbilirubinaemia of newborn infants ≥ 35 weeks' gestational age

Hyperbilirubinaemia is one of the most frequent problems in otherwise healthy newborn infants. Early discharge of the healthy newborn infants, particularly those in whom breastfeeding is not fully established, may be associated with delayed diagnosis of significant hyperbilirubinaemia that has the potential for causing severe neurological impairments. We present the shared Italian guidelines for management and treatment of jaundice established by the Task Force on hyperbilirubinaemia of the Italian Society of Neonatology.

The overall aim of the present guidelines is to provide an useful tool for neonatologists and family paediatricians for managing hyperbilirubinaemia.

Neonatal death suspected to be from sepsis was found to be kernicterus with G6PD deficiency

We cared for a term male infant born to Burmese immigrants. At about 24 hours a total serum bilirubin (TSB) was 9.3 mg/dL, and phototherapy was begun. It was stopped 48 hours later, with a TSB of 10.9 mg/dL, and he was discharged from the hospital with an appointment for a repeat TSB check 48 hours later. A few hours before the appointment he became listless and apneic, and his parents took him to the emergency department of the regional children's hospital, where sepsis was suspected. The TSB was 41 mg/dL. He died 4 hours later, despite intensive care efforts, with opisthotonus and refractory hypotension. Blood drawn before the exchange transfusion had low glucose-6-phosphate dehydrogenase (G6PD) enzymatic activity, and sequencing of the G6PD gene revealed the G6PD Mahidol mutation (c.487G>A). Cultures and postmortem examination did not demonstrate an infectious process, but kernicterus was present. Acute kernicterus can mimic septic shock.

The effect of hematocrit on the efficacy of phototherapy for neonatal jaundice

BACKGROUND

The therapeutic phototherapy action spectrum ranges from 420 to 500 nm. However, a recent report of improved efficacy of fluorescent "turquoise" light (~490 nm) as compared with blue light (~450 nm) underscores the need to define an optimal action spectrum for precision-targeted phototherapy using very narrow wavelength ranges.

METHODS

We used a current semi-empirical model of the optical properties of skin for robust calculations of the fraction of light absorbed by bilirubin at various wavelengths that could be confounded by hemoglobin (Hb), melanin, and skin thickness. Applying assumptions regarding the wavelength dependence of bilirubin photochemistry, "action spectra" were assembled from the calculated values.

RESULTS

All the calculated action spectra displayed a peak between 472 and 480 nm (most at 476 nm), which is a significant shift from the well-reported 460 nm absorption peak of bilirubin. Of note, the relative amplitudes of the action spectra showed an inverse relationship with hematocrit (Hct).

CONCLUSION

We speculate that a narrow range of light at 476 nm would be 60% more effective than blue (broadband) fluorescent lamps. Because Hb serves as a major competitor of bilirubin for light absorption, the calculations also predict that the efficacy of phototherapy is dependent on the Hct. A high Hct could reduce therapeutic efficiency.

Tin-mesoporphyrin in the treatment of refractory hyperbilirubinemia due to Rh incompatibility

We describe the use of tin-mesoporphyrin (SnMP) in the treatment of an infant with Rh hemolytic disease. The infant's hyperbilirubinemia responded to phototherapy but every time the phototherapy was discontinued, the serum bilirubin rebounded and repeat phototherapy was necessary. A single intramuscular dose of SnMP on day 18 eliminated the need for further phototherapy and allowed us to discharge this infant.

Fundamentals of phototherapy for neonatal jaundice

Phototherapy is the use of visible light for the treatment of hyperbilirubinemia in the newborn. This relatively common therapy lowers the serum bilirubin level by transforming bilirubin into water-soluble isomers that can be eliminated without conjugation in the liver. The dose of phototherapy is a key factor in how quickly it works; dose in turn is determined by the wavelength of the light, the intensity of the light (irradiance), the distance between the light and the baby, and the body surface area exposed to the light. Commercially available phototherapy systems include those that deliver light via fluorescent bulbs, halogen quartz lamps, light-emitting diodes, and fiberoptic mattresses. Proper nursing care enhances the effectiveness of phototherapy and minimizes complications. Caregiver responsibilities include ensuring effective irradiance delivery, maximizing skin exposure, providing eye protection and eye care, careful attention to thermoregulation, maintaining adequate hydration, promoting elimination, and supporting parent-infant interaction.

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.

When should phototherapy be stopped? A pilot study comparing two targets of serum bilirubin concentration

OBJECTIVE

The objective of this study was to compare the outcome of two groups of jaundiced newborns randomized to one of the two targets of total serum bilirubin (TSB) for phototherapy discontinuation.

DESIGN

Infants treated with phototherapy were assigned to two groups: in the 'high-threshold' group, phototherapy was interrupted when TSB decreased to >/=1 mg/dL (17 micromol/L) below the limit requiring phototherapy and in the 'low-threshold' group when TSB decreased to >/=3 mg/dL (51 micromol/L) below the same limit.

RESULTS

Fifty-two infants were enrolled, 25 in the high- and 27 in the low-threshold group. Phototherapy duration was significantly shorter in the high- than in the low-threshold group (22.3 +/- 13 vs. 27.6 +/- 12 h, respectively, p = 0.03). Length of hospital stay was 84+/-30 h in the high- and 94 +/- 24 h in the low-threshold group (p = 0.05). Additional phototherapy was required in 20% of the high- versus 18% of the low-threshold group (p = 0.58). In the presence of haemolysis or G6PD deficiency, 28% of the infants required re-phototherapy and 8.3% when such factors were absent (p = 0.06).

CONCLUSION

Phototherapy duration may be shortened by using higher TSB limits for interruption. When hyperbilirubinaemia is accompanied by risk factors, the infants should be followed for longer periods, since some of them will need re-phototherapy.

Israel guidelines for the management of neonatal hyperbilirubinemia and prevention of kernicterus

Despite publication of guidelines for the prevention and management of hyperbilirubinemia in term and late-preterm newborn infants, kernicterus, although rare, continues to occur. Guidelines written for use in one country may not always be universally appropriate. Bearing this in mind, a committee appointed by the Israel Neonatal Society has formulated a set of guidelines, based on those of the American Academy of Pediatrics (2004), but adapted to the realities of the Israeli scene. The guidelines include methods of surveillance of jaundice, prediction of jaundice, assessment of risk factors, discharge planning and post-discharge follow-up, in addition to therapeutic guidelines including indications for phototherapy, exchange transfusion and the use of intravenous immune globulin. Availability of these guidelines to the international community may offer direction to physicians of other countries who may be setting up guidelines for use in their own communities.

Fundamentals of phototherapy for neonatal jaundice

Phototherapy is the use of visible light for the treatment of hyperbilirubinemia in the newborn. This relatively common therapy lowers the serum bilirubin level by transforming bilirubin into water-soluble isomers that can be eliminated without conjugation in the liver. The dose of phototherapy largely determines how quickly it works; the dose, in turn, is determined by the wavelength of the light, the intensity of the light (irradiance), the distance between the light and the infant, and the body surface area exposed to the light. Commercially available phototherapy systems include those that deliver light via fluorescent bulbs, halogen quartz lamps, light-emitting diodes, and fiberoptic mattresses. Proper nursing care enhances the effectiveness of phototherapy and minimizes complications. Caregiver responsibilities include ensuring effective irradiance delivery, maximizing skin exposure, providing eye protection and eye care, carefully monitoring thermoregulation, maintaining adequate hydration, promoting elimination, and supporting parent-infant interaction.

Efficacy of phototherapy for neonatal jaundice is increased by the use of low-cost white reflecting curtains

OBJECTIVE

To determine whether the addition of low-cost reflecting curtains to a standard phototherapy unit could increase effectiveness of phototherapy for neonatal jaundice.

DESIGN

Randomised controlled clinical trial.

SETTING

Level-one nursery of the Hospital Universiti Sains Malaysia, Kelantan, Malayasia.

PATIENTS

Term newborns with uncomplicated neonatal jaundice presenting in the first week of life.

INTERVENTIONS

Phototherapy with white curtains hanging from the sides of the phototherapy unit (study group, n = 50) was compared with single phototherapy without curtains (control group, n = 47).

MAIN OUTCOME MEASURES

The primary outcome was the mean difference in total serum bilirubin measured at baseline and after 4 h of phototherapy. The secondary outcome was the duration of phototherapy.

RESULTS

The mean (standard deviation) decrease in total serum bilirubin levels after 4 h of phototherapy was significantly (p<0.001) higher in the study group (27.62 (25.24) micromol/l) than in the control group (4.04 (24.27) micromol/l). Cox proportional hazards regression analysis indicated that the median duration of phototherapy was significantly shorter in the study group (12 h) than in the control group (34 h; chi(2) change 45.2; p<0.001; hazards ratio 0.20; 95% confidence interval 0.12 to 0.32). No difference in adverse events was noted in terms of hyperthermia or hypothermia, weight loss, rash, loose stools or feeding intolerance.

CONCLUSION

Hanging white curtains around phototherapy units significantly increases efficacy of phototherapy in the treatment of neonatal jaundice without evidence of increased adverse effects.