Noninvasive measurement of total serum bilirubin in a multiracial predischarge newborn population to assess the risk of severe hyperbilirubinemia

UGT1A1, SLCO1B1, and SLCO1B3 polymorphisms vs. neonatal hyperbilirubinemia: is there an association?

BACKGROUND

Jaundice is a physiological phenomenon; however, severe hyperbilirubinemia occurs in only 5 to 6% of the healthy newborn population. It has been suggested that genetic variation could enhance the risk of hyperbilirubinemia when coexpressed with other icterogenic conditions.

METHODS

The study included newborns with a gestational age of greater than 35 wk and weights greater than 2,000 g with indications for phototherapy. The polymorphisms from UGT1A1 (rs8175347), SLCO1B1 (rs4149056 and rs2306283), and SLCO1B3 (rs17680137 and rs2117032) were analyzed by capillary electrophoresis and hydrolysis probes.

RESULTS

A total of 167 hyperbilirubinemic infants and 247 control subjects were enrolled. The gender, ABO incompatibility, birth weight, and gestational age differed between the groups, but the allelic and genotypic frequency of the polymorphisms from SLCO1B genes did not. In logistic regression, the ABO incompatibility, gestational age, and polymorphic T allele of rs2117032 remained in the model. The presence of this polymorphism seemed to provide protection from hyperbilirubinemia. The individuals who were homozygous for the G allele of rs2306283 and who were glucose 6-phosphate-dehydrogenase deficient were more frequent among the cases.

CONCLUSION

Although genetic variation accounts for a good part of this condition, the association between different polymorphisms and environmental factors has yet to be explained.

Is it worthwhile using a transcutaneous bilirubinometer in the nursery?

Jaundice is a potential threat to neonatal health and/or life. The advantages and limitations of transcutaneous determination of bilirubin concentration and current devices are briefly discussed in this paper.

Evaluation of maternal knowledge level about neonatal jaundice

OBJECTIVE

To evaluate the knowledge of mothers on neonatal jaundice.

METHODS

This study was conducted on 161 mothers who had given birth to healthy newborns at Izmir Aegean Gynecology and Obstetrics Hospital between January 2010 and April 2010. A questionnaire was used to assess the mothers' knowledge on neonatal jaundice. Knowledge was evaluated as "sufficient" or "insufficient" based on responses. Sufficiently informed mothers were compared with insufficiently informed group for the knowledge level about neonatal jaundice.

RESULTS

The rate of insufficiently informed mothers was 53.6%. Logistic regression analysis showed that education level and having a previous offspring with jaundice were independent variables affecting the mothers' knowledge level. Low education level was found to increase the probability of the mothers' knowledge level to be insufficient by 2.1 folds (OR 2.1, 95% CI 1.3-3.4; p = 0.003). Being informed beforehand by a previous offspring with jaundice increased the probability of the mothers' knowledge to be sufficient by twofolds (OR 2, 95% CI 1.1-3.7; p = 0.03).

CONCLUSION

It is found that the mothers' knowledge about neonatal jaundice is insufficient. Maternal education level and having a previous offspring with jaundice are major factors affecting the knowledge of the mothers on hyperbilirubinemia.

Total serum bilirubin levels during the first 2 days of life and subsequent neonatal morbidity in very low birth weight infants: a retrospective review

To determine the relationship between total serum bilirubin (TSB) during the first 2 days of life and subsequent neonatal morbidity in very low birth weight (VLBW, less than 1500 g) infants. We performed a prospective study of 582 VLBW infants born between July 1, 2005 and December 31, 2009. TSB was measured in umbilical cord blood (UCB), at 24 and 48 h after birth. Demographic and clinical characteristics of infants in hospital were recorded. The interaction between TSB variables during the first 48 h of life and subsequent neonatal morbidity were assessed in logistic regression analyses adjusted for multiple risk factors. It was found that TSB in UCB was in a negative correlation with occurrence of respiratory distress syndrome (RDS) [OR 0.626, 95% confidence interval (95% CI): 0.446-0.879, p = 0.007], and there was also a negative correlation between TSB in UCB and occurrence of intraventricular hemorrhage (IVH) [OR 0.695, 95% CI 0.826-0.981, p = 0.020]. However, TSB in UCB positively correlated with hyperbilirubinemia [OR 2.471, 95% CI 1.326-3.551, p = 0.012], and TSB at 24 h after birth was also in a positive correlation with early onset sepsis (EOS) [OR 1.299, 95% CI 1.067-1.582, p = 0.011]. VLBW infants with low TSB levels in UCB were more likely to develop RDS and IVH, and those with low TSB levels in UCB were less likely to develop hyperbilirubinemia. Infants with high TSB levels at 24 h after birth were more likely to develop EOS. The protective effect of raised TSB in UCB with respect to RDS and IVH warrants further investigation.

Risk assessment strategy for prediction of pathological hyperbilirubinemia in neonates

OBJECTIVE

To evaluate combined ability of clinical risk factors and transcutaneous bilirubin (TcB) in predicting pathological hyperbilirubinemia (PHB) needing treatment during first week of life in healthy term and late preterm neonates.

METHODS

This prospective cohort study included healthy neonates with gestation ≥35 wk and birth weight ≥2000 g. TcB was measured with a multi-wavelength transcutaneous bilirubinometer (Bilichek®) at 30 ± 12 h of postnatal age. Follow-up was conducted as per American Academy of Pediatrics guidelines. For diagnosis of PHB, TcB was measured at each follow-up visit. Serum bilirubin was measured if TcB was >15 mg/dL or within 2 mg/dL of phototherapy cut-off.

RESULTS

Among 462 neonates [birth weight (g; mean ± SD): 2711 ± 431, gestation (wk; median, IQR): 38 (37-39), male: 52%] enrolled in the study, 392 (84.9%) completed followup and PHB was observed in 65 (16.6%) neonates. Discriminant ability of risk model, including both clinical risk factors and TcB, was better than the risk models with clinical risk factors or TcB alone (c-statistic: 0.86 vs. 0.74 vs. 0.77). On logistic regression analysis risk factors found significant were TcB (OR: 1.65, 95% CI: 1.4-1.9), gestation at birth (OR: 0.6, 95% CI: 0.50-0.77) and primiparity (OR: 2.1, 95% CI: 1.1-3.9). A risk prediction score was developed with these three risk factors as ordinal/dichotomous variables. Negative and positive predictive values for score <8 and >12 were 97% and 46%, respectively.

CONCLUSIONS

Risk score consisting of TcB, gestation at birth and parity status was able to accurately predict pathological hyperbilirubinemia in derivation cohort of healthy term and late preterm north Indian neonates.

Covered skin transcutaneous bilirubin estimation is comparable with serum bilirubin during and after phototherapy

OBJECTIVE

To determine whether transcutaneous bilirubin (TcB) from covered skin (TcB-C) during and after discontinuing phototherapy (PHT) is reliable in treating neonatal jaundice.

STUDY DESIGN

In this prospective observational study, before starting PHT, part of the forehead was covered. TcB-C and TcB from exposed skin (TcB-E) to PHT were measured before starting PHT, on a 12-hourly basis while receiving PHT and 6 h after stopping PHT. We used ANOVA (analysis of variance) and Bonferroni's t-tests.

RESULT

A total of 39 infants were enrolled (mean gestation 39 weeks, 51% males and 80% Hispanic). The mean TSB over all time periods was 10.9±2.4, TcB-C 10.9±2.4 and TcB-E 7.2±3.4. Before PHT, there were no significant differences in bilirubin by all three techniques. TcB-C was not significantly different from TSB at any time point. However, TcB-E was significantly lower during PHT and after stopping PHT.

CONCLUSION

TcB-C is a reliable method in the management of neonatal jaundice.

Impact of a transcutaneous bilirubinometry program on resource utilization and severe hyperbilirubinemia

OBJECTIVES

Our goal was to assess the impact of programmatic and coordinated use of transcutaneous bilirubinometry (TcB) on the incidence of severe neonatal hyperbilirubinemia and measures of laboratory, hospital, and nursing resource utilization.

METHODS

We compared the neonatal hyperbilirubinemia-related outcomes of 14 796 prospectively enrolled healthy infants ≥35 weeks gestation offered routine TcB measurements in both hospital and community settings by using locally validated nomograms relative to a historical cohort of 14 112 infants assessed by visual inspection alone.

RESULTS

There was a 54.9% reduction (odds ratio [OR]: 2.219 [95% confidence interval (CI): 1.543-3.193]; P < .0001) in the incidence of severe total serum bilirubin values (≥342 µmol/L; ≥20 mg/dL) after implementation of routine TcB measurements. TcB implementation was associated with reductions in the overall incidence of total serum bilirubin draws (134.4 vs 103.6 draws per 1000 live births, OR: 1.332 [95% CI: 1.226-1.446]; P < .0001) and overall phototherapy rate (5.27% vs 4.30%, OR: 1.241 [95% CI: 1.122-1.374]; P < .0001), a reduced age at readmission for phototherapy (104.3 ± 52.1 vs 88.9 ± 70.5 hours, P < .005), and duration of phototherapy readmission (24.8 ± 13.6 vs 23.2 ± 9.8 hours, P < .05). There were earlier (P < .01) and more frequent contacts with public health nurses (1.33 vs 1.66, P < .01) after introduction of the TcB program.

CONCLUSIONS

Integration of routine hospital and community TcB screening within a comprehensive public health nurse newborn follow-up program is associated with significant improvements in resource utilization and patient safety.

Validation of transcutaneous bilirubin nomogram in identifying neonates not at risk of hyperbilirubinaemia: a prospective, observational, multicenter study

BACKGROUND

Transcutaneous bilirubin (TcB) measurement is widely used as screening for neonatal hyperbilirubinaemia.

AIMS

To prospectively validate TcB measurement using hour-specific nomogram in identifying newborn infants not at risk for severe hyperbilirubinaemia.

STUDY DESIGN

prospective, observational, multicenter.

SUBJECTS

2167 term and late preterm infants born in 5 neonatal units in the Lazio region of Italy.

METHODS

All neonates had simultaneous TcB and total serum bilirubin (TSB) measurements, when jaundice appeared and/or before hospital discharge. TcB and TSB values were plotted on a percentile-based hour-specific transcutaneous nomogram previously developed, to identify the safe percentile able to predict subsequent significant hyperbilirubinaemia defined as serum bilirubin >17 mg/dL or need for phototherapy.

RESULTS

Fifty-five babies (2.5%) developed significant hyperbilirubinaemia. The 50th percentile of our nomogram was able to identify all babies who were at risk of significant hyperbilirubinaemia, but with a high false positive rate. Using the 75th percentile, two false negatives reduced sensitivity in the first 48 hours but we were able to detect all babies at risk after the 48th hour of age.

CONCLUSIONS

This study demonstrates that the 75th percentile of our TcB nomogram is able to exclude any subsequent severe hyperbilirubinaemia from 48 h of life ahead.

Transcutaneous bilirubin levels in an outpatient and office population

OBJECTIVE

The use of transcutaneous bilirubin (TcB) measurements has been studied extensively in the newborn population, but there have been few studies in outpatient populations and none from the offices of practicing pediatricians.

STUDY DESIGN

We performed TcB measurements on a mixed-race population of 120 jaundiced infants, ≥ 35 weeks of gestation, in two hospital-based outpatient clinics, a regional public health nurse follow-up program and two pediatric office practices. Three individual TcB readings were obtained from the mid-sternum, and the average and maximum values were recorded.

RESULT

There was good correlation between the TcB and total serum bilirubin (TSB) measurements (r=0.78, P=0.0). 59% of TSB's were ≥15 mg dl(-1) and, although the number of false-negative readings increased when the TSB values exceeded 15 mg dl(-1), it was nevertheless possible to use TcB measurements to accurately predict the risk of TSB levels ≥ 15 mg dl(-1).

CONCLUSION

In outpatient settings, a TcB measurement with the JM-103 provides a reliable screening method for the identification of hyperbilirubinemia even when the TSB level exceeds 15 mg dl(-1). Using the maximum of three independent measurements reduces the number of false negatives, but increases the number of false positives. The use of TcB measurements in an outpatient practice should be a valuable tool for the practitioner.

Hyperbilirubinemia: current guidelines and emerging therapies

It is estimated that about two thirds of newborns will appear clinically jaundiced during their first weeks of life. As newborns and their mothers spend fewer days in the hospital after birth, the number of infants readmitted yearly in the United States for neonatal jaundice over the last 10 years has increased by 160%. A portion of these infants present to the emergency department, requiring a careful history and physical examination assessing them for the risk factors associated with pathologic bilirubin levels. Although the spectrum of illness may be great, the overwhelming etiology of neonatal jaundice presenting to an emergency department is physiologic and not due to infection or isoimmunization. Therefore, a little more than a good history, physical examination, and indirect/direct bilirubin levels are needed to evaluate an otherwise well-appearing jaundiced newborn. The American Academy of Pediatrics' 2004 clinical practice guidelines for "Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation" are a helpful and easily accessible resource when evaluating jaundiced newborns (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;114/1/297). There are several exciting developments on the horizon for the diagnosis and management of hyperbilirubinemia including increasing use of transcutaneous bilirubin measuring devices and medications such as tin mesoporphyrin and intravenous immunoglobulin that may decrease the need for exchange transfusions.

Transcutaneous bilirubin in exclusively breastfed healthy term newborns up to 12 days of life

OBJECTIVE

To determine the curve of transcutaneous bilirubin in breastfed term neonates up to 12 days of life.

METHODS

In a prospective cohort study, we performed a 12-day evaluation of 223 healthy, exclusively breastfed, appropriate-for-gestational-age neonates who roomed-in for at least 48 hours. Each newborn had forehead transcutaneous bilirubin and body weight measured at the end of 1, 2, 3, 4, 5, 6, 8, 10, and 12 days. Regression analysis was used with bilirubin as a third-degree polynomial function of time. The 25th, 50th, 75th, 90th, and 95th percentile curves were constructed by using the residual mean square for each day.

RESULTS

Patients were 46% white, 34% mixed race, and 20% black, the mean birth weight was 3260 g (range: 2560-4090 g), the mean gestational age was 39.4 weeks (range: 37.0-41.9 weeks), 51% were male, 74% were born by vaginal delivery, and 66% had been breastfed since delivery. The mean highest weight loss was 4.7% (range: 1%-12%) at the second or third day, and in most infants the weight returned to the birth weight at the fifth day. With 2007 total bilirubin measurements, bilirubin concentrations reached the 50th percentile level (5.6 mg/dL) at the third and fourth days and returned to the 24-hour level (4.8 mg/dL) at the sixth day. The 95th percentile bilirubin level was 8.2 mg/dL at 24 hours of life, reached 12.2 mg/dL on the fourth day, and declined to 8.5 mg/dL on the 12th day.

CONCLUSIONS

The transcutaneous bilirubin curve represents the natural history of bilirubinemia in exclusively breastfed healthy term newborns in the first 12 days of life.

Estimation of bilirubin using BiliChektrade mark, a transcutaneous bilirubin measurement device: Effects of gestational age and use of phototherapy

BACKGROUND

Heel puncture to obtain bilirubin measurements is painful for infants and distressing for parents. Transcutaneous bilirubin measurement using BiliChek (Respironics, USA) is easily performed in any setting. Reliable transcutaneous testing should decrease the number of painful procedures in otherwise well infants, reduce the volume of phlebotomy losses in ill newborns, and reduce the need for hospital or specialized clinic visits after discharge.

OBJECTIVE

To correlate bilirubin measurements using the transcutaneous device BiliChek with 'gold standard' serum measurements in well term infants, and in ill term and preterm infants admitted to the authors' neonatal intensive care unit.

METHODS

The study consisted of two phases. In phase 1, informed consent was obtained from mothers of 99 healthy, full-term infants not receiving phototherapy to perform both serum and transcutaneous bilirubin measurements at the time of heel puncture for routine neonatal screening. In phase 2, 56 infants in the neonatal intensive care unit had a total of 99 transcutaneous readings performed at the time serum bilirubin measurements were ordered for clinical reasons by the attending staff. The operators of the transcutaneous device, who were unaware of the serum bilirubin levels, performed readings within 1 h of the heel puncture.

RESULTS

Using a Bland-Altman comparison in the well term infants, the transcutaneous measurements were -32.2 mumol/L to +31.2 mumol/L (1.96 SD); however, 79 (79.8%) of the transcutaneous measurements were within 15 mumol/L of the serum measurements. The variation in preterm infants was greater at -69.6 mumol/L to +62.0 mumol/L, and only 49 (49.5%) were within 15 mumol/L. For infants receiving phototherapy, the variation was -76.3 mumol/L to +49.5 mumol/L, but improved to -40.4 mumol/L to +31.0 mumol/L if an area of skin was patched for testing, approximating the group not receiving phototherapy.

CONCLUSIONS

Transcutaneous bilirubin measurements obtained with the BiliChek instrument were accurate for measuring bilirubin levels in term jaundiced infants not receiving phototherapy and in those receiving phototherapy if an area of skin was patched. The instrument was not as sensitive in the small sample of preterm infants, and a larger study is required before recommending the use of this instrument in this population.

Transcutaneous bilirubin measurement at the time of hospital discharge in a multiethnic newborn population

BACKGROUND

Severe neonatal hyperbilirubinemia continues to occur in healthy newborns. Recent guidelines have supported using transcutaneous devices in estimating bilirubin levels. Previous studies using these devices are limited.

METHODS

Newborns requiring serum bilirubin level measurements before hospital discharge were recruited prospectively. The agreement between a transcutaneous bilirubin (TCB) and total serum bilirubin (TSB) level was assessed. Sensitivity analysis was conducted.

RESULTS

A total of 430 infants were enrolled. Correlation between the values was high (Pearson's correlation coefficient 0.83; Lin's concordance coefficient 0.81 [95% CI 0.77 to 0.84]; P<0.001). The mean (± SD) TSB level was 194±60 μmol/L. The TCB measurement tended to overestimate the value (mean difference 12.7), with wide 95% limits of agreement (-52 μmol/L to 77 μmol/L). Sensitivity and specificity analysis of TCB values allowed estimation of clinically important TSB levels.

CONCLUSIONS

The TCB correlated, but was imprecise in predicting TSB. TCB values can be used at the time of discharge to safely plan care for jaundiced infants if the limits of agreement are considered and clinical judgment is maintained.

Estudo comparativo entre a medida plasmática e transcutânea de bilirrubina em recém-nascidos

OBJETIVO: Comparar as medidas transcutânea e plasmática da bilirrubina antes e durante a fototerapia, em área de pele exposta e coberta, analisando-se a associação com variáveis do recém-nascido (RN). MÉTODOS: Estudo de corte transversal, que avaliou 44 RN entre abril e outubro de 2008. Realizaram-se dosagens transcutâneas (região frontal e esternal) e plasmáticas da bilirrubina antes e 24 horas após o início da fototerapia. Tanto na região frontal como na esternal, ocluiu-se pequena região de pele e obteve-se a medida transcutânea da área coberta e de área adjacente exposta. Calculou-se a associação entre as medidas e variáveis do RN (peso, sexo, raça/cor, idade gestacional e pós-natal) e presença de fatores de risco para hiperbilirrubinemia significativa. RESULTADOS: Houve forte correlação entre a bilirrubina plasmática e a transcutânea, no momento da indicação e após 24 horas de fototerapia, nas regiões frontal e esternal, com intervalos de confiança estreitos tanto a 95 como a 99%. Observou-se que, com relação à medida transcutânea na área coberta, 24 horas após o início da fototerapia, a medida esternal apresentou correlação mais forte com a plasmática (r=0,86; p<0,001). As variáveis do RN analisadas não interferiram nas medidas de bilirrubina. CONCLUSÕES: As dosagens transcutânea e plasmática apresentam correlação forte antes da fototerapia nas regiões frontal e esternal. Após 24 horas de fototerapia, a medida transcutânea esternal em área coberta apresentou melhor correlação.

Prospective validation of a novel strategy for assessing risk of significant hyperbilirubinemia

OBJECTIVE

Our aim was to validate a strategy for assessing the risk of significant hyperbilirubinemia in newborns with gestational ages of ≥35 weeks by combining predischarge bilirubin percentile data with gestational age data, for a European, predominantly white population.

METHODS

We conducted a prospective cohort study with 463 newborns with gestational ages of ≥35 weeks who were admitted to the well-infant nursery. Total bilirubin levels were measured daily until discharge and once after discharge, between the third and eighth days of life, by using a Bilicheck device (Respironics, Murrysville, PA). The values obtained (<52 hours) were plotted on an hour-specific bilirubin nomogram to determine the infant's bilirubin percentile, expressed as a risk zone. Patients were assigned to 1 of 3 risk groups (very low, low, or high) on the basis of a combination of risk zone and gestational age data and were monitored prospectively for the development of significant hyperbilirubinemia. The 95% confidence interval (CI) for the prevalence of significant hyperbilirubinemia was estimated with the binomial distribution method.

RESULTS

Forty-four infants (11%) developed significant neonatal hyperbilirubinemia. The risks of developing significant hyperbilirubinemia were 1.3% (95% CI: 0.2%-3.7%) for the very low risk group (n = 230 [58.1%]), 3.4% (95% CI: 0.7%-9.8%) for the low risk group (n = 86 [21.7%]), and 47.50% (95% CI: 36.2%-59.0%) for the high risk group (n = 80 [20.20%]).

CONCLUSIONS

The proposed strategy, based on predischarge bilirubin level and gestational age data, was a valid method for significant hyperbilirubinemia risk assessment in our population.

Transcutaneous bilirubin levels in late preterm neonates

OBJECTIVE

To examine transcutaneous bilirubin (TcB) levels in late preterm neonates.

STUDY DESIGN

Between July 2006 and December 2009, we performed 4387 TcB measurements with a BiliCheck bilirubinometer in 793 healthy late preterm neonates at designated times up to 120 postnatal hours. TcB percentiles are presented on an hour-specific nomogram. Mean increment TcB rates and the rates of increase for different percentiles are calculated as well.

RESULTS

We present a percentile-based nomogram that reflects the natural history of TcB in late preterm neonates up to the fifth day of life. TcB levels demonstrated a different pattern of increase in neonates who developed significant hyperbilirubinemia compared with those who did not. However, the rates of TcB increase were quite similar up to age 48 hours, with a substantial overlap of TcB values between the two groups.

CONCLUSIONS

We developed of a TcB nomogram designated for hour-specific evaluation of hyperbilirubinemia in neonates born between 35(0/7) and 37(6/7) weeks' gestation.

Universal bilirubin screening for severe neonatal hyperbilirubinemia

To reduce the incidence of severe neonatal hyperbilirubinemia affecting newborns with jaundice in the United States and to prevent kernicterus, there is a need to implement proven prevention strategies for severe neonatal hyperbilirubinemia as recommended in the 2004 American Academy of Pediatrics Guidelines for newborns >35 weeks gestational age. The purpose of universal predischarge bilirubin screening is to identify infants with bilirubin levels >75th percentile for age in hours and track those with rapid rates of bilirubin rise (>0.2 mg per 100 ml per h). Early identification has been reported to predict severe hyperbilirubinemia and allow for evidence-based targeted interventions. A systems approach is likely to reduce the preventable causes of acute bilirubin encephalopathy. To do so, highest priority should be given to (i) designating extreme hyperbilirubinemia (total serum bilirubin >427 μmol l(-1) or >25 mg per 100 ml) as a reportable condition by laboratories and health-care providers through public health mandates; (ii) implementation of Joint Commission's Sentinel Report for kernicterus; (iii) nursing outreach to communities for education of prospective parents; (iv) development of clinical pathways to monitor, evaluate and track infants with extreme hyperbilirubinemia; and (v) societal awareness. These efforts should be monitored by a state and national surveillance system in order to critically improve the timeliness and completeness of notifications and to allow evaluation and interventions at the policy and individual family level.

Decreased neonatal jaundice readmission rate after implementing hyperbilirubinemia guidelines and universal screening for bilirubin

Readmission rate for neonatal jaundice approximate 10 per 1000 live births. After applying hyperbilirubinemia guidelines and universal screening for bilirubin in term and near-term newborns, the readmission rate declined significantly from 24 to 3.7 per 1000 live births. Decreased readmission rate for neonatal jaundice may reduce kernicterus rate and health care costs. Further studies are necessary to explore these potential benefits.

Crigler-Najjar syndrome in The Netherlands: identification of four novel UGT1A1 alleles, genotype-phenotype correlation, and functional analysis of 10 missense mutants

Crigler-Najjar syndrome (CN), caused by deficiency of UGT isoform 1A1 (UGT1A1), is characterized by severe unconjugated hyperbilirubinemia. In this study we have analyzed 19 CN patients diagnosed in The Netherlands (18) and in Belgium (1), and have identified 14 different UGT1A1 mutations, four of which are novel. Two mutations were present in several unrelated patients, suggesting the presence of two founder effects in The Netherlands. In addition, we show linkage of the UGT1A1 *28 promoter polymorphism (rs5719145insTA) to three structural mutations. Functional studies of partial active UGT1A1 mutants are limited. Therefore, we performed in vitro studies to determine the functional activity of seven missense mutants identified in this study and of three reported previously. In addition to bilirubin, we also determined their activity toward eight other UGT1A1 substrates. We demonstrate that five mutants have residual activity that, depending on the substrate, varies from not detectable to 94% of wild-type UGT1A1 activity. The identification of four novel pathogenic mutations and the analysis of residual activity of 10 UGT1A1 missense mutants are useful for clinical diagnosis, and provides new insights in enzyme activity, whereas the identification of two founder mutations will speed up genetic counseling for newly identified CN patients in The Netherlands.

Transcutaneous bilirubin levels for the first 120 postnatal hours in healthy neonates

OBJECTIVE

The objective of this study was to provide data on transcutaneous bilirubin (TcB) levels for the first 120 postnatal hours and to develop an hour-specific TcB nomogram for healthy term and near-term neonates.

METHODS

From September 2005 to August 2008, we obtained 14864 TcB measurements from 2818 healthy neonates (gestational age >or= 35 weeks and birth weight >or= 2000 g). All measurements were performed with the BiliCheck bilirubinometer, at designated times from 12 to 120 postnatal hours. TcB percentiles for each designated time were calculated and used for the development of an hour-specific nomogram. TcB percentiles for neonates who required phototherapy are also presented.

RESULTS

The developed TcB nomogram reflects the natural history of TcB levels in healthy neonates up to the fifth postnatal day. A different pattern of TcB increasing rate was noted in neonates who did and did not require phototherapy but with substantial overlap of TcB values between the 2 groups.

CONCLUSIONS

We provide data on TcB levels for the first 120 postnatal hours from a large population of white, healthy, term and near-term neonates. We also present a percentile-based TcB nomogram designated for noninvasive and hour-specific evaluation of neonatal hyperbilirubinemia.

Impact of skin tone on the performance of a transcutaneous jaundice meter

AIM

To evaluate the performance of the Konica Minolta/Air-Shields JM-103 jaundice meter on the basis of infant skin tone during the early neonatal period.

METHODS

Infants were prospectively categorized into light, medium and dark skin tone groups relative to two reference colours. Transcutaneous bilirubin readings were taken at predetermined intervals through the early neonatal period on a convenience sample of 938 healthy infants > or =37 weeks gestation. Serum bilirubin measurements were drawn routinely with metabolic studies and repeated in the presence of an elevated transcutaneous reading or clinically significant jaundice.

RESULTS

Multivariate linear regression analysis showed a significant impact on serum and transcutaneous bilirubin agreement by skin tone. Highest precision and lowest bias were observed for medium skin toned infants. Greater disagreement between serum and transcutaneous measurements was noted at serum bilirubin concentrations >200 micromol/L. Insufficient numbers of dark skin toned infants were enrolled to evaluate fully the performance of the jaundice meter for this group.

CONCLUSION

The JM-103 jaundice meter displayed good correlation with serum bilirubin concentrations in light and medium skin tone infants, although it showed a tendency to under-read in the lighter skin tone group and to over-read in the darker skin tone group. The device shows excellent performance characteristics for use as a screening device.

Bhutani-based nomograms for the prediction of significant hyperbilirubinaemia using transcutaneous measurements of bilirubin

AIM

Prospectively establish the relationship between transcutaneous bilirubin (TcB) and total serum bilirubin (TSB), and develop nomograms similar to Bhutani's nomograms, based on our TcB data.

METHODS

Our study sample was from a total population of 1069 infants, near term and term healthy newborns, admitted during 2.5 month period of the study. TSB was performed on all infants who were felt to be clinically jaundiced. Before obtaining the TSB, a TcB was performed (Jaundice Meter Minolta/Draeger JM-103). Measurements were performed on two sites: forehead and mid-sternum, and the mean of both measurements was calculated.

RESULTS

A total of 1091 paired measurements were obtained from 628 infants. Linear regression showed a significant relation between TSB and TcB (R(2) of 0.846). In multiple regression analysis, all independent variables studied, i.e. gestational age (or birthweight), age at sampling and ethnicity had a negligible influence on the relationship. We subsequently developed our local-nomograms of hour-specific mean TcB with 40, 75 and 95 percentile lines.

CONCLUSIONS

In our local settings and population, we found a reliable correlation between laboratory measurements of TSB and TcB. We were able to develop our local-Bhutani-based TcB nomograms for screening babies during hospital stay and pre-discharge for assessing the risk of hyperbilirubinaemia.

Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice

OBJECTIVES

We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates.

METHODS

Newborns, > or =35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines).

RESULTS

A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: -8.9%, 95% CI: -2.4% to -15.4%; p = 0.008).

CONCLUSION

Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874).

Comparison between transcutaneous bilirubinometry and total serum bilirubin measurements in preterm infants <35 weeks gestation

Background

Neonatal hyperbilirubinaemia is a common treatable cause of brain injury. The treatment for this condition is phototherapy. The decision whether to use phototherapy is currently dependent upon serum bilirubin assay results. However, repeated blood sampling is not only traumatic but may also be a cause of anaemia in neonates. We evaluated a transcutaneous bilirubin assay method to determine whether it was suitable for routine use in preterm infants.

Methods

One hundred and eighty-three transcutaneous bilirubin measurements were taken contemporaneously with blood samples for laboratory measurement of serum bilirubin. The study was carried out with informed parental consent and approval by the local research ethics committee.

Results

The transcutaneous bilirubin method (Bili Chek®) exhibited a consistent positive bias compared with the laboratory bilirubin assay. Consequently, for a given detection rate, the transcutaneous method had a higher screen positive rate, i.e. more neonates would be given phototherapy if transcutaneous bilirubin results were used to decide. There was a margin of safety in the transcutaneous bilirubin assay calibration.

Conclusion

The BiliChek transcutaneous bilirubin assay is a safe alternative to laboratory bilirubin assay in deciding whether to give preterm neonates phototherapy.

Comparison of a new transcutaneous bilirubinometer (Bilimed) with serum bilirubin measurements in preterm and full-term infants

Background

The gold standard to assess hyperbilirubinemia in neonates remains the serum bilirubin measurement. Unfortunately, this is invasive, painful, and costly. Bilimed^®, a new transcutaneous bilirubinometer, suggests more accuracy compared to the existing non-invasive bilirubinometers because of its new technology. It furthermore takes into account different skin colours. No contact with the skin is needed during measurement, no additional material costs occur. Our aim was to assess the agreement between the Bilimed^® and serum bilirubin in preterm and term infants of different skin colours.

Methods

The transcutaneous bilirubin measurements were performed on the infant's sternum and serum bilirubin was determined simultaneously. The agreement between both methods was assessed by Pearson's correlation and by Bland-Altman analysis.

Results

A total of 117 measurement cycles were performed in 99 term infants (group1), further 47 measurements in 38 preterm infants born between 34 - 36 6/7 gestational weeks (group 2), and finally 21 measurements in 13 preterm infants born between 28 - 33 6/7 gestational weeks (group 3). The mean deviation and variability (+/- 2SD) of the transcutaneous from serum bilirubin were: -14 (+/- 144) μmol/l; -0.82 (+/- 8.4) mg/dl in group 1, +16 (+/- 91) μmol/l;+0.93(+/- 5.3) mg/dl in group 2 and -8 (+/- 76) μmol/l; -0.47 (+/- 4.4) mg/dl in group 3. These limits of agreement are too wide to be acceptable in a clinical setting. Moreover, there was to be a trend towards less good agreement with increasing bilirubin values.

Conclusion

Despite its new technology the Bilimed^® has no advantages, and more specifically no better agreement not only in term and near-term Caucasian infants, but also in non-Caucasian and more premature infants.

Does measuring the changes in TcB value offer better prediction of Hyperbilirubinemia in healthy neonates?

OBJECTIVE

We evaluated the diagnostic value of changes in transcutaneous bilirubin (TcB) levels for prediction of subsequent hyperbilirubinemia in healthy term and late-preterm neonates.

METHODS

Neonates at 35 weeks of gestation were enrolled in a prospective study. Two TcB determinations were performed for all enrolled neonates (N = 358). The first assessment (TcB(1)) was performed at 24 +/- 6 hours of age, followed by a second (TcB(2)) >or=12 hours later. Changes in TcB levels were calculated. TcB values were plotted on an hour-specific serum bilirubin nomogram, and risk zones were recorded. Of the 358 neonates enrolled, 325 neonates (91%) were monitored for hyperbilirubinemia until 5 days of age.

RESULTS

The mean ages of TcB(1) and TcB(2) estimations were 23 +/- 4 hours and 42 +/- 4 hours, respectively. A total of 14.9% of neonates (48 of 325 neonates) developed hyperbilirubinemia by 5 days of age. The sensitivity, specificity, and positive and negative likelihood ratios for prediction of subsequent hyperbilirubinemia for TcB(1) (zone >2, >75th percentile) were 80.4%, 58.0%, 1.9, and 0.34; those for TcB(2) (zone >2, >75th percentile) were 82.6%, 79.0%, 4.0, and 0.22; and those for the change in TcB levels (>0.18 mg/dL per hour, >75th percentile) were 82.5%, 82.9%, 4.8, and 0.21, respectively. Gestational age, TcB risk zone, and change in TcB levels were found to be independent predictors of subsequent hyperbilirubinemia.

CONCLUSIONS

Single TcB measurements at 30 to 48 hours predict hyperbilirubinemia with a reasonably high degree of accuracy. Changes in TcB levels do not offer any added clinical benefit.

Impact of universal bilirubin screening on severe hyperbilirubinemia and phototherapy use

OBJECTIVE

The goal was to assess the impact of universal bilirubin screening on severe hyperbilirubinemia and phototherapy use.

METHODS

In this retrospective cohort study of 358086 infants of > or =35 weeks and > or =2000 g born between January 1, 1995, and June 30, 2007, we obtained demographic data, bilirubin levels, and codes for inpatient phototherapy from existing databases. We compared the incidence of high total serum bilirubin (TSB) levels and phototherapy before and after implementation of universal screening and examined risk factors for high TSB levels.

RESULTS

A total of 38182 infants (10.6%) were born at facilities that had implemented universal bilirubin screening. Compared with infants born at facilities that were not screening, these infants had a 62% lower incidence of TSB levels exceeding the American Academy of Pediatrics exchange guideline (0.17% vs 0.45%; P < .001), received twice the inpatient phototherapy (9.1% vs 4.2%; P < .001), and had slightly longer birth hospitalization lengths of stay (50.9 vs 48.7 hours; P < .001). Of those receiving phototherapy, 56% after initiation of universal screening had TSB levels at which phototherapy was recommended by the guideline, compared with 70% before screening. The adjusted odds ratio for developing TSB levels exceeding the guideline value was 0.28 (95% confidence interval: 0.20-0.40) for those born at a facility using TSB screening and 0.28 (95% confidence interval: 0.19-0.42) for those born at a facility using transcutaneous bilirubin screening.

CONCLUSIONS

Universal bilirubin screening was associated with a significantly lower incidence of severe hyperbilirubinemia but also with increased phototherapy use.

Transcutaneous bilirubin nomogram for prediction of significant neonatal hyperbilirubinemia

OBJECTIVE

The goal was to develop a predictive nomogram, based on transcutaneous bilirubin (TcB) measurements, for assessment of the risk of significant hyperbilirubinemia in healthy term and near-term neonates.

METHODS

A total of 10382 TcB measurements were performed with 2039 healthy neonates (gestational age of > or =35 weeks and birth weight of > or =2000 g), with a BiliCheck bilirubinometer (SpectRx, Norcross, GA), at designated time points between 12 and 120 hours of life. According to their severity, these TcB measurements were selectively cross-checked with a direct spectrophotometric device, and significant hyperbilirubinemia was defined on the basis of the hour-specific threshold values for phototherapy proposed by the American Academy of Pediatrics. With the use of likelihood ratios (LRs), the high- and low-risk demarcators for each designated time were calculated and presented on an hour-specific nomogram.

RESULTS

Significant hyperbilirubinemia was documented for 122 neonates (6%). At 24 hours of life, the high-risk zone of the nomogram had 73.9% sensitivity and a positive LR of 12.1 in predicting significant hyperbilirubinemia, whereas the low-risk zone had 97.7% sensitivity and a negative LR of 0.04. At 48 hours, the high-risk zone had 90% sensitivity and a positive LR of 12.1, whereas the low-risk zone had 98.8% sensitivity and a negative LR of 0.02. In our study population, the probability of significant hyperbilirubinemia would be >35% for values in the high-risk zone and <0.5% for values in the low-risk zone of the nomogram.

CONCLUSIONS

We provide a predictive TcB tool that could allow for a noninvasive, risk-based approach to neonatal hyperbilirubinemia.

Routine transcutaneous bilirubin measurements combined with clinical risk factors improve the prediction of subsequent hyperbilirubinemia

OBJECTIVE

To evaluate predischarge transcutaneous bilirubin (TcB) measurements combined with risk factors as predictors of the risk of a subsequent total serum bilirubin (TSB) >or=17 mg per 100 ml (291 micromol l(-1)).

STUDY DESIGN

Routine TcB measurements are obtained daily for all infants in our well baby nursery. We performed a nested case-control study comparing all 75 infants who had been readmitted with TSB >or=17 mg per 100 ml (291 micromol l(-1)) between 1 February 2005 and 28 February 2007 with randomly selected controls that had not been readmitted.

RESULT

Between 1 February 2005 and 28 February 2007, 11 456 infants were discharged from the well baby nursery. Seventy-five infants (0.65%) were readmitted at a mean age of 110+/-29.9 h with a TSB>or=17 mg per 100 ml (291 micromol l(-1)). All received phototherapy. Using logistic regression analysis, three variables were statistically significant for predicting cases: the maximum predischarge TcB percentile group (P<0.0001, adjusted odds ratio (AOR), >95th percentile 148; 95% confidence interval (CI) 21 to >999, AOR 76 to 95th percentile 15; 95% CI 3.1 to 70, AOR 50 to 75th percentile 6.1; 95% CI 1.3 to 28 compared with <50th percentile), exclusive breastfeeding (P<0.0001, AOR 11; 95% CI 3.7 to 34) and gestational age (P=0.0057, AOR 35 to 36 6/7 week 21; 95% CI 2.3 to 185, AOR 37 to 37 6/7 week 15; 95% CI 1.9 to 115, AOR 38 to 38 6/7 week 1.8; 95% CI 0.3 to 11, AOR 39 to 39 6/7 week 1.1; 95% CI 0.2 to 7 AOR >or=41 week 0.88; 95% CI 0.1 to 10 compared with 40 to 40 6/7 week infants). These three variables provided the best prediction of a case (c=0.885, area under the receiver operating characteristic curve) and this prediction was significantly better than the use of the clinical risk factors, gestation and exclusive breastfeeding, alone (c=0.770, P<0.001) or the TcB percentile grouping alone (c=0.766, P<0.001). Substituting the TcB rate of rise (c=0.903, P=0.316) or the last measured TcB (c=0.873, P=0.292) for the maximum TcB measurement did not significantly improve the predictors of a case.

CONCLUSION

Combining predischarge TcB levels with two clinical risk factors-gestational age and exclusive breastfeeding-significantly improves the prediction of subsequent hyperbilirubinemia.

Skin bilirubin measurement during phototherapy in preterm and term newborn infants

BACKGROUND

The few existing studies evaluating the reliability of transcutaneous bilirubin monitoring during phototherapy gave controversial results.

AIMS

To evaluate the accuracy of transcutaneous bilirubin measurement in a large population of newborn infants, during phototherapy.

STUDY DESIGN AND METHODS

Total serum bilirubin and transcutaneous bilirubin on patched and unpatched skin areas were simultaneously measured in newborn infants undergoing phototherapy. Transcutaneous measurements were performed with a multiwavelength transcutaneous bilirubinometer (Respironics BiliCheck). The Passing-Bablok regression and the Bland-Altman plot were used to estimate the relationship between serum and transcutaneous bilirubin.

RESULTS

We studied 364 newborn infants with a mean (SD) gestational age of 34.6 (3) weeks and a mean birth weight of 2371 (805) grams. Total serum bilirubin, patched transcutaneous bilirubin and unpatched transcutaneous bilirubin were similar before phototherapy. After 52 (33) hours of phototherapy, the difference between serum bilirubin and patched transcutaneous bilirubin was 0.2 (3.1) mg/dL (not significant) while the difference between serum bilirubin and unpatched transcutaneous bilirubin was 3.2 (3.0) mg/dL (p<0.001). Statistical analysis showed a good agreement between serum bilirubin and patched transcutaneous bilirubin, while unpatched transcutaneous bilirubin underestimates serum levels. The difference between patched and unpatched values was significantly lower in preterm than in term infants (2.8 mg/dL vs. 3.6 mg/dL; p<0.001).

CONCLUSION

BiliCheck can be safely used for the evaluation of bilirubin levels in newborn infants under phototherapy. Its reliability on patched skin of the forehead is high enough to consistently reduce blood draws and to ascertain when to discontinue phototherapy. Because of the individual variance, any clinical decision has to be taken on the basis of the transcutaneous bilirubin trend more than on a single value.

Screening for severe neonatal hyperbilirubinemia

Screening for severe neonatal hyperbilirubinemia is integral to newborn care. Predischarge risk assessment relies on documentation of visual jaundice: age at onset and progression; identification of clinical risk such as late prematurity and bruising; with determination of total bilirubin (blood or transcutaneous assay) adjusted for age in hours. Along with promotion of breastfeeding, coordination between birthing hospital and medically supervised outpatient follow-up, a systems approach allows for a safer and effective means to prevent adverse effects of extreme hyperbilirubinemia.

Evaluation of transcutaneous bilirubinometry in preterm neonates

OBJECTIVE

To determine the accuracy and precision of transcutaneous bilirubin (TcB) measurements in preterm neonates.

STUDY DESIGN

Neonates were stratified into three groups on the basis of gestational age: 24 to 28 weeks (Group 1, n=30), 29 to 31 weeks (Group 2, n=29) and 32 to 34 weeks (Group 3, n=31). TcB was measured using the Draeger Air Shields JM-103, and when possible, measurements were made by two observers. TcB and total serum bilirubin (TSB) measurements were compared, and interobserver precision for TcB measurements was assessed.

RESULT

Correlations between TcB and TSB ranged from 0.79 to 0.92. Most of the differences between TcB and TSB were +/-2 mg per 100 ml, and there was no trend for the difference to increase with increasing bilirubin values. Sensitivity, specificity and negative predictive values ranged from 0.67 to 1.0, 0.29 to 0.81 and 0.60 to 1.0, respectively. Intraclass correlations were 0.87 to 0.92.

CONCLUSION

TcB correlates significantly with TSB in preterm neonates, and interobserver precision is significant. Routine measurement of TcB in preterm neonates may provide enhanced clinical monitoring for hyperbilirubinemia.

Hyperbilirubinemia and Transcutaneous Bilirubinometry

Background: Neonatal jaundice or hyperbilirubinemia is a common occurrence in newborns. Although most cases of neonatal jaundice have a benign course, severe hyperbilirubinemia can lead to kernicterus, which is preventable if the hyperbilirubinemia is identified early and treated appropriately.

Content: This review discusses neonatal jaundice and the use of transcutaneous bilirubin (TcB) measurements for identification of neonates at risk of severe hyperbilirubinemia. Such a practice requires appropriate serial testing and result interpretation according to risk level from a nomogram that provides bilirubin concentrations specific for the age of the neonate in hours. In this context, we have evaluated the potential impact on clinical outcome and limitations of TcB methods in current use.

Summary: TcB measurement is a viable option in screening neonates to determine if they are at risk for clinically significant hyperbilirubinemia. Total serum bilirubin should be measured by a clinical laboratory if a newborn is shown to be at higher risk for clinically significant hyperbilirubinemia. In addition, external quality assessment to identify biases and operator training issues should be part of any TcB monitoring program.

Identification of neonates at risk for hazardous hyperbilirubinemia: emerging clinical insights

Hyperbilirubinemia is the most common condition requiring evaluation and treatment in neonates. Identifying among all newborns those few at risk to develop marked hyperbilirubinemia is a clinical challenge. Clinical, epidemiologic, and genetic risk factors associated with severe hyperbilirubinemia include late preterm gestational age, exclusive breastfeeding, glucose-6-phosphate dehydrogenase deficiency, ABO hemolytic disease, East Asian ethnicity, jaundice observed in the first 24 hours of life, cephalohematoma or significant bruising, and history of a previous sibling treated with phototherapy. It is increasingly apparent that the etiopathogenesis of severe hyperbilirubinemia is often multifactorial, and emerging evidence suggests that combining risk factor assessment with measurement of predischarge total serum or transcutaneous bilirubin levels will improve hyperbilirubinemia risk prediction.

Analysis of transient otoacoustic emissions and brainstem evoked auditory potentials in neonates with hyperbilirubinemia

Hyperbilirubinemia is toxic to the auditory pathways and to the central nervous system, leaving sequelae such as hearing loss and encephalopathy.

Aim

to assess the hearing of neonates with hyperbilirubinemia, using transient evoked otoacoustic emissions (TOAEs) and brainstem evoked auditory potentials (BEAP). Prospective study.

Materials and Methods

we had two groups: GI (n-25), neonates with hyperbilirubinemia; GII (n-22), neonates without hyperbilirubinemia and without risk factors for hearing loss. All the neonates had up to 60 days of life and were submitted to TOAE and BEAP.

Results

12 neonates from GI and 10 from GII were girls and 13 from GI and 12 from GII were boys. TOAEs were present in all the children, however with lower amplitudes in GI, especially in the frequencies of 2 and 3KHz (p < 0.05). Regarding the BEAP, we observed a mild PV and LI-V increase in BI. The alterations observed in these tests do not correlate to the serum levels of bilirubin.

Conclusions

in neonates with hyperbilirubinemia, we noticed lower TOAE amplitudes and mild PV and LI-V increase, indicating cochlear and retrocochlear disorders, stressing the importance of using both tests and carefully reading them in these evaluations.

Point of care testing: transcutaneous bilirubinometry in neonates

Physicians taking care of infants in the first days of life are often faced with neonatal jaundice, especially in an era where post-partum discharge occurs earlier and assessment of newborn bilirubinemia status is required prior to discharge. The Canadian Pediatric Society and the American Academy of Pediatrics have developed and published guidelines for the diagnosis and management of hyperbilirubinemia in newborns. Point of care testing refers to any test performed outside of laboratory by clinical personnel and close to the site of patient care. Based on a summary of multiple reports during the last twenty years, we realize that devices which provide a non-invasive transcutaneous bilirubin (TcB) measurement have proven to be very useful as screening tools and provide a valid estimate of the total serum bilirubin level (TSB). Published data suggest that these devices provide measurements within 30-50 micromol/L of the TSB levels and can replace laboratory measurement particularly when TSB levels are less than 260 micromol/L. At the present time, in the literature, evidence is insufficient to abandon neonatal serum bilirubin testing and replace it with TcB. Any measurement, TSB or TcB, has potential for error. However, we have evidence that TcB, can help avoiding potential errors associated with even visual assessment of jaundice and may be useful as screening device to detect significant jaundice and decrease a large number of unnecessary skin punctures. The current manuscript is based on a careful comprehensive literature review concerning neonatal hyperbilirubinemia. We consider that this manuscript will help clinicians and laboratory professionals in the management of neonatal jaundice.

Comparative evaluation of two simple diffuse reflectance models for biological tissue applications

We present a comparative evaluation of two simple diffuse reflectance models for biological tissue applications. One model is based on a widely accepted and used in biomedical optics implementation of diffusion theory, and the other one is based on a semiempirical approach derived from basic physical principles. We test the models on tissue phantoms and on human skin, utilizing a standard six-around-one optical fiber probe for light delivery and collection. We show that both models are suitable for use with an optical fiber probe and illustrate the potential, applicability, and validity range of the models.

Is visual assessment of jaundice reliable as a screening tool to detect significant neonatal hyperbilirubinemia?

OBJECTIVE

To assess the reliability of visual assessment of bilirubin levels (BiliEye) in newborns as a screening tool to detect significant neonatal hyperbilirubinemia.

STUDY DESIGN

5 neonatologists and 17 nurses estimated 3,532 BiliEye in 1,129 term and late preterm (> or = 35 weeks) infants before discharge from the nursery, at 62 +/- 24 hours. Total serum bilirubin (TSB) levels were measured concomitantly.

RESULTS

Mean TSB and BiliEye were 6.7 +/- 2.9 mg/dL (range, 0.4-18.2 mg/dL) and 6.6 +/- 3.2 mg/dL (range, 0.0-17.2 mg/dL), respectively, with good correlation (Pearson's r = 0.752, P < .0001), but other measures of agreement were poor. 61.5% of the 109 babies with TSB levels in high-risk zones were clinically misclassified. The area under curve (AUC) of the receiver-operating characteristics plotted for these high-risk zones was 0.825, but became low for early discharge (< or = 36 hours; AUC = 0.638) and late preterm (35-37 weeks; AUC = 0.613). There was significant interobserver variation (low weighted kappa, 0.363).

CONCLUSIONS

Although there was good correlation between BiliEye and actual TSB level, visual assessment was unreliable as a screening tool to detect significant neonatal hyperbilirubinemia before discharge. Babies with TSB levels within high-risk zones may be clinically misdiagnosed as low-risk, resulting in inadequate follow-up.

Neonatal jaundice and stool production in breast- or formula-fed term infants

It has remained unclear whether the amount of fecal fat excreted in the stool and stool production influences the severity of neonatal jaundice. We determined the relationship between stool production, fecal fat excretion and jaundice in healthy breast-fed (BF) or formula-fed (FF) (near-)term neonates. From postnatal day 1-4, we quantitatively collected stools from 27 FF and 33 BF infants in daily fractions. Stool production and fecal fat contents were related to unconjugated bilirubin (UCB) levels, as determined by transcutaneous bilirubinometry (TcB). Bilirubin concentrations and stool production did not differ between FF and BF neonates during the study period. Neonatal bilirubin levels were not inversely correlated with stool production. FF and BF infants had similar fecal fat excretion rates. The stool production of FF infants was profoundly lower in the present study than in a 1985 study by De Carvalho et al. [J Pediatr (1985) 107:786-790]. We conclude that increased jaundice during the first postnatal days in healthy term neonates can no longer be attributed to breast-feeding and speculate that improved absorbability of formulas since 1985 has contributed to similar fat excretion and stool production in FF and BF neonates in 2007.

Evaluation of the BiliChek being used on hyperbilirubinemic newborns undergoing home phototherapy

CONTEXT

Newborns are often screened prior to discharge for hyperbilirubinemia. Transcutaneous bilirubin analyzers, such as the BiliChek, are promoted as screening tools, but it is unclear whether they also function well as monitoring devices. Newborns on home phototherapy require frequent determinations of serum bilirubin levels to monitor therapy effects. A transcutaneous bilirubin analyzer would be helpful to limit blood draws and enhance staff efficiency. We evaluated the accuracy of the BiliChek analyzer in this setting.

OBJECTIVE

Is the BiliChek sufficiently accurate to monitor the effectiveness of home phototherapy and establish when to terminate therapy?

DESIGN

Paired serum bilirubin results and results from the BiliChek were obtained from newborns on home phototherapy during daily home health care visits.

RESULTS

The BiliChek demonstrates a negative bias (mean bias, -1.71 mg/dL; 95% confidence interval, -1.89 to -1.52 mg/dL) compared with serum bilirubin values. This bias worsens as the serum bilirubin level rises. If a value of 14 mg/dL or less obtained using the BiliChek had been used as the cutoff for termination of phototherapy, 45% of newborns would have had therapy terminated prematurely. If, knowing the negative bias of the BiliChek, the cutoff for termination of therapy was set at less than or equal to 11 mg/dL, then 29% of newborns would have had therapy terminated prematurely.

CONCLUSIONS

The values obtained using the BiliChek, compared to serum bilirubin values, have a negative bias that worsens at the higher bilirubin levels expected in newborns at home on phototherapy. The BiliChek does not provide sufficient accuracy to be utilized to monitor newborns on home phototherapy or to ascertain when to discontinue such therapy.

Assessment of transcutaneous bilirubinometry in hospitalized adults

BACKGROUND

Transcutaneous techniques to measure serum bilirubin have been validated in neonates but not in adult patients. We evaluated transcutaneous bilirubinometry (TcB) in adults at risk for or diagnosed with hepatic dysfunction to determine if this technology has clinical use in quantifying the presence and magnitude of hyperbilirubinemia.

DESIGN

Unblinded, consecutive hospitalized adult patients (n = 80) from the general surgery, trauma surgery, and liver resection/transplantation services of a tertiary care, university-affiliated medical center, who were having serum bilirubin measurements performed, underwent transcutaneous bilirubin measurement from the forehead, sternum, forearm, and deltoid. Transcutaneous bilirubin measurements were repeated each time serum bilirubin measurements were performed.

RESULTS

Transcutaneous bilirubin measurements from the forehead correlated with serum bilirubin better (r, 0.963) than measurements from the forearm (r, 0.792), deltoid (r, 0.922), or sternum (r, 0.928). Forehead TcB detected hepatic dysfunction (serum bilirubin > or = 2 mg/dL) by receiver operator curves (area under the curve = 0.971) and sternum (area under the curve = 0.970) and better than deltoid and forearm measurements (area under the curve = 0.935 and 0.893, respectively). A Bland-Altman plot demonstrated that forehead measurements became less accurate as the magnitude of hyperbilirubinemia increased.

CONCLUSIONS

Forehead TcB correlated best with serum bilirubin levels but became less accurate at higher values. Refinements in the technology will be required before this technique, although promising, can be considered for routine clinical application in adults being evaluated for hyperbilirubinemia.