Transcutaneous Bilirubin Measurements Research Articles

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

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. 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. The transcutaneous bilirubin method (BiliChek) 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. 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

BackgroundThe 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.MethodsThe 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.ResultsA 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.ConclusionDespite 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?

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

Implementing and Validating Transcutaneous Bilirubinometry for Neonates

Noninvasive, transcutaneous bilirubin (TcB) measurement is an attractive option for neonates, but opinions about its usefulness vary among studies. We collected paired measurements of TcB and serum bilirubin (SB) in 343 term neonates using the BiliCheck meter (SpectRx, Norcross, GA) and 3 different SB methods. Correlations between SB and TcB were similar for all laboratory methods and TcB measurement sites. However, TcB bias varied depending on the comparison SB method and TcB measurement site. TcB bias also varied with race when measurements were done on the forehead but not when they were done on the sternum. Several factors must be considered before implementing TcB measurement: (1) Each laboratory instrument has its own unique relationship to TcB. (2) The chosen measurement site affects the relationship. (3) Race can affect TcB bias when the measurement is taken on the forehead. Properly used, TcB measurement, especially when taken from the sternum, can be a useful screening method for neonatal jaundice.

Transcutaneous Bilirubin Nomogram for Prediction of Significant Neonatal Hyperbilirubinemia

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

Systematic Review of Screening for Bilirubin Encephalopathy in Neonates

Severe neonatal hyperbilirubinemia is associated with chronic bilirubin encephalopathy (kernicterus). To systematically review the effectiveness of specific screening modalities to prevent neonatal bilirubin encephalopathy. We identified studies through Medline searches, perusing reference lists and by consulting with US Preventive Services Task Force lead experts. We included English-language publications evaluating the effects of screening for bilirubin encephalopathy using early total serum bilirubin (TSB), transcutaneous bilirubin (TcB) measurements, or risk scores. Severe hyperbilirubinemia was used as a surrogate for possible chronic bilirubin encephalopathy, because no studies directly evaluated the latter as an outcome. We calculated the sensitivity and specificity of early TSB, TcB measurements, or risk scores in detecting hyperbilirubinemia. Ten publications (11 studies) were eligible. Seven (2 prospective) studies evaluated the ability of risk factors (n = 3), early TSB (n = 3), TcB (n = 2), or combinations of risk factors and early TSB (n = 1) to predict hyperbilirubinemia (typically TSB > 95th hour-specific percentile 24 hours to 30 days postpartum). Screening had good ability to detect hyperbilirubinemia: reported area-under-the-curve values ranged between 0.69 and 0.84, and reported sensitivities and specificities suggested similar diagnostic ability. Indirect evidence from 3 descriptive uncontrolled studies suggests favorable associations between initiation of screening and decrease in hyperbilirubinemia rates, and rates of treatment or readmissions for hyperbilirubinemia compared with the baseline of no screening. No study assessed harms of screening. Effects of screening on the rates of bilirubin encephalopathy are unknown. Although screening can predict hyperbilirubinemia, there is no robust evidence to suggest that screening is associated with favorable clinical outcomes.

The influence of skin temperature and skin perfusion on the cephalocaudal progression of jaundice in newborns

Despite being widely recognized, the cephalocaudal progression of jaundice in newborns (Kramer's Rule) has never been satisfactorily explained. The aim of this study was to test the hypothesis that the cephalocaudal progression of jaundice in newborns is related to regional differences in skin temperature and skin perfusion. A convenience sample of 50 infants was included in the study. On each infant, a transcutaneous bilirubin, skin temperature and capillary refill time measurement was made at five sites; the forehead, sternum, lower abdomen, mid thigh and sole. The relationship between the three variables was studied by analysis of variance. The transcutaneous bilirubin measurements upheld Kramer's observation, being significantly higher at the head and chest than at the thigh and sole (P < 0.001). A similar pattern was found for both skin temperature and capillary refill, both significantly different at the head compared to the sole (P < 0.001). The results of the study support the hypothesis that the cephalocaudal progression of jaundice in newborns is a consequence of diminished capillary blood flow in distal parts of the body. It is hypothesized that newborn infants preferentially perfuse their head and proximal parts of their body in the first few days of life, leading to higher temperatures and increased bilirubin deposition at these sites.

Hyperbilirubinemia in the Newborn Infant ≥35 Weeks’ Gestation: An Update With Clarifications

In July 2004, the Subcommittee on Hyperbilirubinemia of the American Academy of Pediatrics (AAP) published its clinical practice guideline on the management of hyperbilirubinemia in the newborn infant ≥35 weeks of gestation,1 and a similar guideline was published in 2007 by the Canadian Paediatric Society.2 Experience with implementation of the AAP guideline suggests that some areas require clarification. The 2004 AAP guideline also expressed hope that its implementation would “reduce the incidence of severe hyperbilirubinemia and bilirubin encephalopathy… .” We do not know how many practitioners are following the guideline, nor do we know the current incidence of bilirubin encephalopathy in the United States. We do know, however, that kernicterus is still occurring in the United States, Canada, and Western Europe.3–7 In 2002, the National Quality Forum suggested that kernicterus should be classified as a “serious reportable event,”8 sometimes termed a “never event,”9 implying that with appropriate monitoring, surveillance, and intervention, this devastating condition can, or should, be eliminated. Although this is certainly a desirable objective, it is highly unlikely that it can be achieved given our current state of knowledge and practice.10 In certain circumstances (notably, glucose-6-phosphate dehydrogenase [G6PD] deficiency, sepsis, genetic predisposition, or other unknown stressors), acute, severe hyperbilirubinemia can occur and can produce brain damage despite appropriate monitoring and intervention. In addition to clarifying certain items in the 2004 AAP guideline, we recommend universal predischarge bilirubin screening using total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) measurements, which help to assess the risk of subsequent severe hyperbilirubinemia. We also recommend a more structured approach to management and follow-up according to the predischarge TSB/TcB, gestational age, and other risk factors for hyperbilirubinemia. These recommendations represent a consensus of expert opinion based on the available evidence, and they are supported by … Address correspondence to M. Jeffrey Maisels, MB, BCh, DSc, Beaumont Children's Hospital, 3601 W. 13 Mile Rd, Royal Oak, MI 48073. E-mail: JMaisels{at}beaumont.edu

The effect of prebiotics in the management of neonatal hyperbilirubinaemia

Breast milk oligosaccharides such as galacto-oligosaccharides (scGOS) and fructo-oligosaccharides (lcFOS) can influence the intestinal microbial flora. The latter, in turn, can modulate several intestinal and extraintestinal functions, including bilirubin metabolism. Supplementing infant formula with a prebiotic mixture might then be a novel and safe intervention to manage mild neonatal hyperbilirubinaemia. To investigate the effect of dietary supplementation with prebiotics on moderate hyperbilirubinaemia in healthy, term infants. A prospective, double-blind, clinical trial was performed on seventy-six consecutive newborns who were randomly assigned to receive a formula containing 0.8 g/dL of a mixture from scGOS and lcFOS (ratio 9:1), or maltodextrines as placebo for 28 days. Bilirubin levels were determined by the transcutaneous bilirubin measurement within 2 h after birth (T1), at 24, 48 and 72 h and at 5, 7, 10 and 28 days of life. The number of stool per day was also recorded. Neonates receiving prebiotics showed a larger number of stools over all the duration of dietary intervention compared to that of those on placebo (Repeated Measures ANOVA p < 0.001; day 28 3.4 +/- 0.0.9 vs 1.7 +/- 0.9, respectively; Dunn test p < 0.05). Neonates whose formula was supplemented with prebiotics showed a lower transcutaneous bilirubin that was statistically significant from 72 h of life (5.46 +/- 1.6 vs 7.07 +/- 2.49, post hoc Dunn test, p < 0.05) throughout the duration of the dietary intervention (day 28 2.41 +/- 0.4 vs 2.85 +/- 0.5, post hoc Dunn test, p < 0.05). The addition of prebiotics to standard infant diet might represent a novel strategy to help control neonatal hyperbilirubinaemia.

The Clinical Study of Anti-jaundice Lotion to Treat Neonatal Jaundice

Objective To explore the preventive and therapeutic effect of Anti-jaundice Lotion on neo-natal jaundice, and the possible mechanism. Methods 400 normal newborns were randomly divided into treat-ment group and control group. The treatment group was taken a bath with Anti-jaundice Lotion for 20 minutes. The control group was taken a bath with a conventional method:Comparing the two groups about the degree of physiological jaundice in the fifth day after their birth and the incidence of hyperbilirubinemia. Results Trans-cutaneous bilirubin measurement on newborn in the fifth day of the treatment group was lower than the control group. Conclusion : Anti-jaundice Lotion has a certain preventive effect on neonatal jaundice and reduces the bili-rubin level. This method is simple, economic, and has a high compliance of parents. Key words: Anti-jaundice Lotion; treatment; prevention; neonatal jaundice

Hyperbilirubinemia and Transcutaneous Bilirubinometry

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. 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. 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.

Magnetism and Magnetoresistance: Attractive Prospects for Point-of-Care Testing?

There is a strong consensus that an ideal diagnostic test should be rapid, noninvasive, reagentless, inexpensive, and suitable for application at the point of care. For most tests, this ideal is a distant prospect. One recent success has been reflectance spectrophotometry, which is now used for transcutaneous bilirubin measurements in neonates (BiliCheck™; http://bilichek.respironics.com). Another is the noninvasive measurement of blood oxygen saturation using red and infrared absorption measurements (e.g., 660 and 920 nm). However, early hope for a broad range of infrared-based noninvasive testing has been dashed. Although successful for oxygen saturation, the expansion of the scope of this technology to the main prize, namely blood glucose, has not been successful, and in fact has been the source of major controversy. In view of the slow progress in reagentless noninvasive technologies, efforts have continued in ways to reduce the number of steps, reagents, and manipulations in more conventional assays, particularly for disposable assays intended for point of care, where speed, error-free operation, and ease of use are paramount. In the current range of point-of-care tests, 2 endpoints dominate. The first and earliest point-of-care tests were portable tablet- and powder-based colorimetric assays that were available in the early twentieth century. The second generation of point-of-care test devices was based on electrochemical measurements using a meter. Many assays have been effectively reduced to a single-addition-and-read format; for multistep point-of-care assays, such as immunoassays, assay simplification has been achieved using self-contained cartridges that enable reagent and sample manipulations, as exemplified by lateral flow devices. Magnetism is emerging as a possible source of point-of-care assay innovation (1). The exploitation of magnetism in clinical assays is not new. Magnetic particles are commonly used as solid phases for immobilizing reagents to facilitate …

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.

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

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

Ictericia neonatal: evaluación clínica de un bilirrubinómetro transcutáneo

Background Transcutaneous bilirubinometers provide non-invasive data on newborn jaundice. The aim of this study is to evaluate whether the measurement of transcutaneous bilirubin can be correlated with serum bilirubin, and to find out whether gestational age, weight birth, race or hours of life affect those measurements. Method Descriptive observational cross-sectional study on a sample of 65 simultaneous measurement of transcutaneous (TcB) and serum bilirubin (TSB). Results The correlation coefficient between both methods was 0.923. Race, gestational age and birth weight tends to not have any effects on the levels of transcutaneous bilirubin. Conclusion Although bilirubinometer measurements tend to underestimate serum bilirubin, especially in patients with high levels, it is a useful technique as a screening tool in the evaluation of hyperbilirubinaemia.

Evaluation of transcutaneous bilirubinometry in preterm neonates

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

An Hour-specific Nomogram for Transcutaneous Bilirubin Values in Term and Late Preterm Hispanic Neonates

We sought to determine percentile values for hour-specific transcutaneous bilirubin (TcB) measurements in Hispanic neonates during the first 72 hours of age. Neonates with gestational age >or= 35 weeks and body weight >or= 2100 g were included. All neonates were screened with JM-103 TcB measurements at a minimum of every 24 hours by nursing personnel, and only TcB values obtained in Hispanic neonates with postnatal ages of 10 to 74 hours were analyzed. The 5th, 25th, 50th, 75th, and 95th percentile curves were determined. These data were compared with a previously published TcB nomogram predominantly composed of white, non-Hispanic neonates. A total of 3284 TcB values were measured in 2005 neonates. A nomogram was constructed for this exclusively Hispanic population, identifying the 5th, 25th, 50th, 75th, and 95th percentile curves. The 95th percentile values at 24, 48, and 72 hours were 7.6, 11.0, and 12.4 mg/dL, respectively. The comparison between our results and those of the previously published study indicated that small but consistent differences between the two study populations were apparent, with the Hispanic neonates having significantly higher TcB values at the majority of time points analyzed. These observations were made despite a higher proportion of neonates >or= 40 weeks' gestation ( p < 0.001) and a lower proportion exclusively breast-fed ( p < 0.001) in the Hispanic population versus those in the previous study. Although higher bilirubin levels for certain populations are well documented, such differences in Hispanic neonates have not been confirmed. A TcB nomogram for Hispanic neonates is presented as a tool that will aid the clinician in the management of jaundice for this population. Compared with the previous study, this report indicates that although differences were relatively small, significantly higher TcB values were observed in the Hispanic population.

Clinical implication of the difference between transcutaneous bilirubinometry and total serum bilirubin for the classification of newborns at risk of hyperbilirubinemia

Objectives 1) To determine the relationship between transcutaneous bilirubin measurements (TcB), performed using BiliCheck™ or Minolta Air-Shields JM-103®, and total serum bilirubin levels (TSB) and 2) to evaluate the predictive accuracy of TcB measurements for risk using the nomogram recommended by the Canadian Pediatric Society (CPS). Methods A total of 154 healthy term neonates from the newborn nursery at McMaster Children's Hospital meeting the inclusion criteria were enrolled. TcB measurements were performed within 30 min of obtaining the TSB measurement. Results Both devices showed a good correlation with the laboratory method (BiliCheck™-Vitros, R 2 = 0.86; Minolta Air-Shields JM-103®-Vitros, R 2 = 0.85), but underestimated the serum bilirubin. Applying the risk classification using the 40th, 75th, and 95th percentile of the Bhutani nomogram a 6%, 0%, and 1% false negative rate was found for BiliCheck™ and 62%, 74% and 81% for the Minolta Air-Shields JM-103® device. After correcting for the differences using either the bias or the 95% CI the false negative rate was reduced to zero in all cases. Conclusion TcB measurements cannot be directly applied to a TSB nomogram but must be adjusted for any observed biases in order to avoid misclassifying newborns at risk for hyperbilirubinemia.

Neonatal jaundice: a critical review of the role and practice of bilirubin analysis

Neonatal jaundice is common, and usually harmless, because of physiological jaundice or breast-feeding. In some neonates unconjugated bilirubin concentration, coupled with other risk factors, is sufficient to allow free bilirubin to cross the blood-brain barrier and cause kernicterus. Another subgroup of infants is jaundiced because of elevated conjugated bilirubin; a marker for a number of pathological conditions. Bilirubin measurement must identify those infants at risk. Transcutaneous bilirubin measurement is increasingly used in healthy infants, especially before early discharge or at home, to assess the need for laboratory bilirubin measurement. Transcutaneous measurements are not covered by laboratory quality assessment schemes. Guidelines on management of neonatal jaundice utilize age in hours and other risk factors to define bilirubin action thresholds, which may be as low as 100 micromol/L for sick premature infants, whereas early discharged babies may only present after bilirubin concentrations are extremely high. Hence, there is a requirement for accurate total bilirubin measurement from <100 to >500 micromol/L, with sufficient precision to assess the rate of bilirubin change with time. Babies presenting with late jaundice always require conjugated bilirubin measurement. It is of concern that many total and direct bilirubin automated kit methods suffer from haemolysis interference, while use of in-house methods or modification of commercial methods has virtually disappeared. External quality assessment has a vital role in providing data on different methods' performance, including accuracy, precision and susceptibility to interference. Laboratories should consider whether their adult bilirubin methods are suitable for neonates.

Assessment of Transcutaneous Bilirubinometry in Hospitalized Adults

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. 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. 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. 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.