A new transcutaneous bilirubinometer, BiliCheck, used in the neonatal intensive care unit and the maternity ward

Demystifying non-invasive approaches for screening jaundice in low resource settings: a review

All national and international pediatric guidelines universally prescribe meticulous bilirubin screening for neonates as a critical measure to mitigate the incidence of acute bilirubin encephalopathy (ABE) and Kernicterus. The prevailing gold standard for jaundice detection in neonates necessitates invasive blood collection, followed by subsequent biochemical testing. While the invasive procedure provides dependable bilirubin measurements and continues to be the sole gold standard diagnostic method for assessing bilirubin concentration. There exists a pressing need to innovate non-invasive screening tools that alleviate the sampling stress endured by newborns, mitigate iatrogenic anemia, and expedite the turnaround time for obtaining results. The exploration of non-invasive modalities for bilirubin measurements is gaining momentum, driven by the overarching goal of minimizing the number of pricks inflicted upon neonates, thereby rendering screening a swift, efficient, comfortable, and dependable process. This comprehensive review article delves extensively into the array of non-invasive approaches and digital solutions that have been proposed, implemented, and utilized for neonatal bilirubin screening, with a particular emphasis on their application in low-resource settings. Within this context, the review sheds light on the existing methodologies and their practical applications, with a specific focus on transcutaneous bilirubin meters. Moreover, it underscores the prevailing open challenges in this domain and outlines potential directions for future research endeavors. Notably, the review underscores the imperative need for robust educational programs targeted at both families and healthcare personnel to expedite the process of seeking timely care for neonatal jaundice. Additionally, it underscores the necessity for the development of enhanced screening and diagnostic tools that can offer greater accuracy in clinical practice.

Performance of smartphone application to accurately quantify hyperbilirubinemia in neonates: a systematic review with meta-analysis

Neonatal jaundice is a common clinical condition that can progress to severe hyperbilirubinemia if identification and intervention are delayed. In this study, we aimed to analyze the current evidence on the accurate performance of smartphone applications to quantify bilirubin levels. PubMed, Embase, Emcare, MEDLINE, the Cochrane Library, and Google Scholar were searched from inception until July 2022. Grey literature was searched on "OpenGrey" and "MedNar" databases. We included prospective and retrospective cohort studies that recruited infants with a gestation of ≥ 35 weeks and reported paired total serum bilirubin (TSB) and smartphone app-based bilirubin (ABB) levels. We conducted the review using the guidelines of the Cochrane Collaboration Diagnostic Test Accuracy Working Group and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-diagnostic test accuracy (PRISMA-DTA) statement. The data were pooled using the random effects model. The outcome of interest was agreement between ABB and TSB measurements, provided as correlation coefficient, mean difference, and standard deviation. Certainty of evidence (COE) was assessed based on GRADE guidelines. Fourteen studies were included in the meta-analysis. The number of infants in individual studies ranged between 35 and 530. The pooled correlation coefficient (r) between ABB and TSB was 0.77 (95% CI 0.69 to 0.83; p < 0.01). Reported sensitivities for predicting a TSB of 250 µmol/L in individual studies ranged between 75 and 100% and specificities ranged from 61 to 100%. Similarly, a sensitivity of 83 to 100% and a specificity of 19.5 to 76% were reported for predicting a TSB of 205 μmol/L. Overall COE was considered moderate.    Conclusion: Smartphone app-based bilirubin estimation showed a reasonable correlation to TSB levels. Well-designed studies are required to determine its utility as a screening tool for various TSB cut-off levels. What is Known: • Neonatal jaundice is a common clinical condition. Timely screening and intervention are necessary to prevent neurological morbidities • Transcutaneous bilirubinometer is a widely used non-invasive screening device but is mostly available in hospital settings and has cost limitations. Researchers have recently explored the utility of smartphone applications to estimate bilirubin levels in neonates. What is New: • This is the first systematic review and meta-analysis conducted to assess the performance of smartphone applications to detect neonatal hyperbilirubinemia. • Bilirubin estimates of newborn infants obtained through smartphone applications had a reasonable correlation with serum bilirubin levels.

Accuracy of transcutaneous bilirubin level measured by a JM-105 bilirubinometer

BACKGROUND

Transcutaneous bilirubin (TcB) measurement is useful, but dissociation with total serum bilirubin (TSB) is a clinical problem in measurement. We verified the accuracy of the latest version of the JM-105 jaundice meter.

METHODS

The TcB, TSB, and hematocrit (Hct) measurements obtained in the first 4 days of life in 2788 term neonates were analyzed.

RESULTS

When divided into 2-mg/dL classes, the difference between the TcB and TSB measurements did not change as TcB increased, but both overestimation and underestimation of TcB increased as TcB increased. At TcB greater than 11 mg/dL, inaccurate measurements with dissociation greater than 2 mg/dL exceeded 10% of the TcB measurements. The Hct value was associated with overestimation and underestimation.

CONCLUSION

To evaluate neonatal jaundice accurately, it is desirable to measure TSB by blood sampling before discharge from obstetrics or in the case of worsening jaundice on day 4 or 5 of life.

A Prospective Comparison of Serum and Transcutaneous Bilirubin in Indian Neonates

The objective of this study was to compare the transcutaneous bilirubin (TcB) with total serum bilirubin (TSB) and to find out the effect of phototherapy on correlation of TcB and TSB during and after phototherapy in Indian neonates. Prospective observational study was performed at neonatal intensive care unit of Uttar Pradesh University of Medical Sciences, Saifai, Etawah, India. Blood samples for TSB estimation of 276 jaundiced neonates were sent, and simultaneously, TcB was measured at forehead and sternum on admission and 12 hourly till discontinuation of phototherapy as per the American Academy of Pediatrics nomogram chart and their correlation was assessed. The effect of phototherapy on correlation of TcB and TSB during and after phototherapy was also observed. The correlation between TSB and TcB was linear and significant for the entire study population over forehead (Pearson's r  = 0.802, R ²  = 0.644, p  < 0.001) as well as over sternum (Pearson's r  = 0.825, R ²  = 0.681, p  < 0.001) before starting the phototherapy. This correlation becomes slightly lower for TSB versus TcB forehead (Pearson's r  = 0.753, R ²  = 0.568, p  < 0.001) and for TSB versus TcB sternum (Pearson's r  = 0.754, R ²  = 0.569, p  < 0.001) after giving phototherapy for at least 24 hours. The correlation coefficients for TSB versus TcB measurements over forehead and sternum were 0.758 and 0.806, respectively, after 36 hours of phototherapy. TcB measurements using the transcutaneous bilirubinometer correlate closely with TSB levels, so it can be used as an easy and rapid noninvasive method of bilirubin measurement in jaundiced neonates.

Can serum albumin level affect the transcutaneous bilirubinometry in term neonates?

BACKGROUND

Jaundice is the quite common benign condition in neonates, but due to its potential toxicity, neonates must be monitored. This study was aimed to evaluate the effect of serum albumin level on the transcutaneous bilirubin (TcB) measurements in term neonates with unconjugated hyperbilirubinemia.

METHODS

Serum albumin and total serum bilirubin (TSB) of 252 jaundiced term neonates were estimated and simultaneously TcB was measured over sternum and the effect of serum albumin on TcB measurements was evaluated.

RESULTS

The correlation between TSB and TcB was linear and significant for the entire cohort. When this correlation was studied separately in the groups with different albumin levels, maximum correlation (r = 0.888, R2 linear = 0.789, p < 0.001) was observed in group 1 with hypo-albuminemia followed by in group 2 with normal albumin levels (r = 0.854, R2 linear = 0.729, p < 0.001) and group 3 with higher albumin levels (r = 0.809, R2 linear = 0.689, p < 0.001). Bland-Altman plot analysis of whole study population demonstrate good agreement between TSB and TcB [95% CI = -0.038 to 0.493 mg/dL, 17/252 = 6.75% outside the limits of agreement, Mean difference = 0.227]. This analysis in different groups also show good agreement between TSB and TcB.

CONCLUSIONS

The correlation between the TSB and TcB may affected by serum albumin level. Therefore, transcutaneous bilirubinometry is not able to replace invasive TSB measurement. However, in the absence of TSB it could be an alternative to measure the level of bilirubin in term neonates.

Large scale validation of a new non-invasive and non-contact bilirubinometer in neonates with risk factors

The study was aimed to evaluate the performance of a newly developed non-invasive and non-contact bilirubin measurement device (AJO-Neo) as an alternative to the conventional invasive biochemical method of total serum bilirubin (TSB) estimation in preterm and term neonates suffering from hyperbilirubinemia associated with risk factors, and/or undergoing phototherapy. The safety and efficacy of the device were assessed in 1968 neonates with gestational ages ranging from 28 to 41 weeks and suffering from incidences of hyperbilirubinemia. Linear regression analysis showed a good correlation between AJO-Neo and the conventional method of TSB (Pearson’s coefficient, r = 0.79). The small bias (0.27 mg/dL) and limits of agreements (− 3.44 to 3.99 mg/dL) were within the range of clinical acceptance. The device was also precise in the measurement of bilirubin levels in all subgroups of the study. The receiver operator curve (ROC), that takes account of both sensitivity and specificity of a device showed high efficacy of the device (area under the curve, AUC = 0.83) in the detection of bilirubin. While monitoring the bilirubin level during phototherapy, the device indicated promising results showing good agreement with TSB. Specificities and sensitivities of the device indicated a much higher accuracy in neonates with associated risk factors for hyperbilirubinemia. Hence, the newly developed device (AJO-Neo) is reliable in measuring bilirubin level in preterm, and term neonates irrespective of gestational or postnatal age, sex, risk factors, feeding behavior or skin color.

Accuracy of transcutaneous bilirubin on covered skin in preterm and term newborns receiving phototherapy using a JM-105 bilirubinometer

OBJECTIVE

Determine the suitability of transcutaneous bilirubin (TCB) as a tool to assess the effectiveness of phototherapy on patched skin.

STUDY DESIGN

A prospective observational study was conducted. We covered a fragment of skin (sternum) with a photo-opaque patch. Several simultaneous TCB and TSB measurements were performed with the JM-105 bilirubinometer. Bland and Altman test evaluated the agreement between bilirubin levels.

RESULT

A total of 217 patients were studied, 48.8% were preterm. The mean difference between TSB and TCB before the start of treatment was 1.07 mg/dL. During phototherapy, differences on covered skin were 0.52, 0.27, and 0.39 mg/dL at 24, 48, and 72 h of therapy respectively. The best correlation was observed at 48 h in preterm infants.

CONCLUSION

The measurement of TCB on patched skin (PTCB) is useful for monitoring the response to phototherapy in term and preterm infants. We use a patch with a removable flap that eases successive measures without disturbing the patients.

Comparison of transcutaneous and serum bilirubin before, under, and after phototherapy in term and late-preterm infants

This study aimed to determine the correlation of transcutaneous bilirubin (TcB) with total serum bilirubin (TSB) in infants receiving phototherapy and the accuracy of TcB for deciding the time to discontinue phototherapy. Paired TcB and TSB levels were assessed in 52 term and 56 late-preterm infants receiving phototherapy. TcB was measured in the unexposed skin of the middle forehead using a noninvasive bilirubin analyzer, BiliChek. TSB was measured every morning, and TcB was measured 2 hours after TSB measurements. Bland-Altman plots, linear regression, multivariate pair wise correlation, and receiver operating characteristic curve (ROC) analyses were performed. Bland-Altman plots before, under, and 24 hours after phototherapy in term and late-preterm infants revealed that TcB and TSB have higher consistency. TcB and TSB showed positive linear correlation before, under, and after phototherapy in both infant groups. In the multivariate pair wise correlations, differences between TcB and TSB were negatively correlated with phototherapy duration in term (correlation coefficient = -0.233, P value = .001) and late-preterm (correlation coefficient = -0.198, P value = .002) infants. Cutoff levels of TcB for discontinuing phototherapy based on the ROC analysis were 13.8 (sensitivity of 90%, specificity of 84%, area under the curve [AUC] 0.94) and 11.8 mg/dL (sensitivity of 84%, specificity of 88%, AUC 0.92) in term and late-preterm infants, respectively. TcB and TSB before, under, and after phototherapy in both term and late-preterm infants showed good correlation and higher consistency with jaundice. To reduce repetitive blood sampling for TSB, TcB measurement may be a reliable method for term and late-preterm infants undergoing phototherapy.

Should transcutaneous bilirubin be measured in preterm infants receiving phototherapy? The relationship between transcutaneous and total serum bilirubin in preterm infants with and without phototherapy

Our objective was to analyze the relationship between transcutaneous bilirubin (TcB) measured on an unexposed area of skin and total serum bilirubin (TSB) in preterm infants before, during, and after phototherapy (PT). For this purpose paired TSB and TcB levels were measured daily during the first ten days after birth in preterm infants of less than 32 weeks’ gestation. TcB was measured with a Dräger Jaundice Meter JM-103 on the covered hipbone. Agreement between TSB and TcB levels was assessed before, during, and after PT. True negative and corresponding false negative percentages were calculated using different TcB cut-off levels. Data are presented as mean (±SD). We obtained 856 paired TcB and TSB levels in 109 preterm infants (66 boys, gestational age 29.4 ± 1.6 weeks and birth weight 1282 g ± 316 g). We found that the difference between TSB and TcB before PT was significantly lower, 44 (±36) μmol/L, than the difference during and after PT, 61 (±29) μmol/L and 63 (±25) μmol/L, respectively; P < 0.01. Blood sampling could be reduced by 42%, with 2% false negatives, when 50 μmol/L was added to the TcB level at 70% of the PT threshold. Our conclusion is that phototherapy enhances underestimation of TSB by TcB in preterms, even if measured on unexposed skin. The use of specific TcB cut-off levels substantially reduces the need for TSB measurements.

Noninvasive transcutaneous bilirubin assessment of neonates with hyperbilirubinemia using a photon diffusion theory-based method

Transcutaneous bilirubinometers are widely used to screen neonatal jaundice. However, it was reported that their accuracy is compromised at low and high bilirubin levels. We used a photon diffusion theory-based method valid in the 450-600 nm wavelength region to overcome this obstacle. Our clinical study results showed that our system could properly determine the transcutaneous bilirubin concentrations at total serum bilirubin levels higher than 14 mg/dL, where a commercial bilirubinometer failed to provide proper results in several cases. These findings suggested that photon diffusion theory could be employed to improve the core algorithm of modern bilirubinometers and enhance their applicability.

Uniform national guidelines do not prevent wide variations in the clinical application of phototherapy for neonatal jaundice

AIM

This study compared the use of phototherapy for neonatal jaundice in all 21 Norwegian neonatal intensive care units (NICUs) from 2013-2014 to improve practice.

METHODS

Information on all types of phototherapy devices was collected, and irradiance was measured from random units at 20 cm and 50 cm from the light source. We gathered information on local practice rules, including the use of single, double or triple phototherapy, how infants were positioned, the frequency of blood sampling, rules for using reflective surfaces and interrupting phototherapy. In every NICU, we asked one nurse with more than five years of experience and one with less than one year to set up phototherapy equipment, then measured the irradiance and distance.

RESULTS

Photodiodes were the most common of the eight types of phototherapy devices used. Rules for the distance from the device to the infant varied from 10 to 40 cm and in practice they varied from 15 to 48 cm, with irradiance ranging from 11.1-56.1 W/m² . There were significant variations between NICUs with regard to the overall treatment duration and duration in most birthweight categories.

CONCLUSION

There were considerable variations in phototherapy practices among Norwegian NICUs. In particular, the significant variations in duration need to be addressed.

Evaluation of transcutaneous bilirubinometer (DRAEGER JM 103) use in Zimbabwean newborn babies

Background

Acute Bilirubin Encephalopathy in the neonatal period is a major cause of permanent disability. Effective screening and surveillance are essential in the newborn period to enable timely management. Noninvasive transcutaneous bilirubin devices have been successfully used for screening in many settings. We evaluated the accuracy of the Draeger JM 103 (Medical Systems, USA) for estimating serum bilirubin in Zimbabwean newborns.

Methods

Paired transcutaneous (forehead and sternum) and serum bilirubin measurements were compared on 283 infants consecutively recruited between 01 August and 30 November 2015 at Harare Hospital Neonatal Unit. Using serum bilirubin as gold standard, Pearson Correlation Coefficient (r) was calculated for the two transcutaneous measurement sites. Linear regression plots of transcutaneous versus serum estimates were performed. Comparison was made between preterm and term babies. Specificity, sensitivity, positive predictive value and negative predictive value of the JM103 were calculated including ROC curves to assess the accuracy of the diagnostic tests.

Results

Fifty-five percent of the babies were male. Median gestational age was 38 weeks (range 28–42). One hundred and fifteen (41%) were preterm. Median postnatal age was 3 days (range 0–10). Serum bilirubin ranged 85–408 μmol/l, transcutaneous bilirubin sternum; 170–544 μmol/l and forehead; 119–510 μmol/l. Correlation between serum and transcutaneous bilirubin (sternum) was 0.77 and between serum and transcutaneous (forehead) was 0.72. Preterm babies correlation for sternum was 0.77 and forehead was 0.75. Term babies correlation for sternum was 0.76 and forehead was 0.70. The sensitivity for the sternum site was 76%, specificity 90%, Positive Predictive Value of 70 and Negative Predictive Value 92. Sensitivity for forehead site was 62%, specificity 95% with a Positive Predictive Value of 80 and Negative Predictive Value of 90. Bland-Altman plot of serum versus transcutaneous measurements showed agreement between the tests. The ROC curves showed that the accuracy of the two diagnostic tests were good with no significant difference between the two, p = 0.2954.

Conclusion

The study demonstrated a strong positive correlation for both sternum and forehead sites with serum bilirubin in this Zimbabwean population of African origin. However, the sternum is a better site for identifying babies with jaundice compared to forehead. The Draeger JM-103 can be used to screening for neonatal jaundice in this population.

Use of a Smartphone App to Assess Neonatal Jaundice

BACKGROUND

The assessment of jaundice in outpatient neonates is problematic. Visual assessment is inaccurate, and more exact methodologies are cumbersome and/or expensive. Our goal in this study was to assess the accuracy of a technology based on the analysis of digital images of newborns obtained using a smartphone application called BiliCam.

METHODS

Paired BiliCam images and total serum bilirubin (TSB) levels were obtained in a diverse sample of newborns (<7 days old) at 7 sites across the United States. By using specialized software, data on color values in the images ("features") were extracted. Machine learning and regression analysis techniques were used to identify features for inclusion in models to predict an estimated bilirubin level for each newborn. The correlation between estimated bilirubin levels and TSB levels was calculated. In addition, the sensitivity and specificity of the estimated bilirubin levels in identifying newborns with high TSB levels were calculated by using 2 recommended decision rules for jaundice screening.

RESULTS

Estimated bilirubin levels were calculated and compared with TSB levels in a diverse sample of 530 newborns (20.8% African American, 26.3% Hispanic, and 21.2% Asian American). The overall correlation was 0.91, and correlations among white, African American, Hispanic, and Asian American newborns were 0.92, 0.90, 0.91, and 0.88, respectively. The sensitivities of BiliCam in identifying newborns with high TSB levels were 84.6% and 100%, respectively, by using 2 decision rules; specificities were 75.1% and 76.4%, respectively.

CONCLUSIONS

BiliCam provided accurate estimates of TSB values, demonstrating that an inexpensive technology that uses commodity smartphones could be used to effectively screen newborns for jaundice.

Prediction of significant hyperbilirubinemia in term neonates by early non-invasive bilirubin measurement

BACKGROUND

Neonatal jaundice is a common problem. We evaluated the utility and best cut-off values of 24-and 48-hour transcutaneous bilirubin indices (TcBI) in predicting subsequent significant hyperbilirubinemia and evaluated various associated maternal and fetal risk factors.

METHODS

TcBI at 24 and 48 hours and serum bilirubin levels at 72 hours of age were obtained for healthy, term, appropriate for gestational age neonates. Neonates with prematurity, birth weight <2500 g, ABO or Rh incompatibility, onset of clinical jaundice <24 hours, clinical suspicion of septicemia, positive pressure ventilation at birth, admission in neonatal intensive care unit and contraindications for BiliChek were excluded. Twently-four and 48-hour TcB indices were assessed as predictors of subsequent hyperbilirubinemia, defined as serum bilirubin >17 mg/dL after 72 hours of life and various cut-offs, and were evaluated by calculating sensitivity, specificity and predictive values.

RESULTS

Of 500 newborns, 4.6% had significant hyperbilirubinemia, 27% had TcBI (mg/dL) <5 at 24 hours, and 27.4% had TcBI <8 at 48 hours. None of them had subsequent hyperbilirubinemia (100% negative predictive value). The percentage of newborns with subsequent hyperbilirubinemia increased from 3.4% to 13.2% as their 24-hour TcBI increased from 6 to above 9 mg/dL and from 4.2% to 7.4% as their 48-hour TcBI increased from 8 to above 11 mg/dL. The best cut-off value was TcBI (mg/dL) 7 (odd ratio=4.86, 95% confidence interval: 1.66-15.22) at 24 hours and 10 (odd ratio=2.87, 95% confidence interval: 1.04-8.29) at 48 hours. Area under the receiver operating characteristic curve for 24- and 48-hour measurements was 0.750 and 0.715, respectively. Maternal premature rupture of membranes, deep transverse arrest, post-date pregnancy, and fetal distress were significant risk factors for hyperbilirubinemia.

CONCLUSIONS

Twenty-four and 48-hour TcB indices are good predictors of subsequent hyperbilirubinemia. Twenty-four-hour TcBI had better predictive ability than 48-hour TcBI.

Defining the limitations of transcutaneous bilirubin measurement in late preterm newborns

OBJECTIVE

The objective of this study is to determine the impact of postnatal age on the bias between transcutaneous (TcB) and total serum bilirubin (TSB), and evaluate a TcB screening protocol.

STUDY DESIGN

Preterm and term infants had paired TcB and TSB performed on days 1 to 3 of life; a subset of preterm infants had measurements on days 4 to 7. Sensitivity and specificity of TcB (plotted on an age-specific TSB nomogram) for prediction of high-intermediate (HIR) or high-risk TSB were calculated.

RESULTS

Median TcB bias was 2.6 and 2.5 mg dl^-1 for term and preterm infants in the first 3 days of life, respectively. However, median bias was 2.2 mg dl^-1 for preterm infants at 4 to 7 days of life. TcB in preterm infants predicted HIR or high-risk TSB with 94% sensitivity and 56% specificity.

CONCLUSION

TcB screening protocols developed for term infants can be used for late preterm infants in the first 3 days of life.

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

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

Reliability of transcutaneous bilirubinometry from shielded skin in neonates receiving phototherapy: a prospective cohort study

OBJECTIVE

To determine the agreement between transcutaneous bilirubin (TcB) measured from shielded skin and serum total bilirubin (STB) in infants (34 to 41 weeks of gestation) with hyperbilirubinemia receiving phototherapy (PT).

STUDY DESIGN

In this prospective cohort study, we shielded a small area of skin on sternum using a commercial photo-opaque patch (BilEclipseTM, Philips Respironics, Murrysville, PA, USA). The TcB from the shielded skin (TcBs) and STB were measured at four time points-before initiation, 12 and 24 h during and once after (12 h) cessation of PT. TcB was measured using multiwavelength transcutaneous bilirubinometer (BiliChek, Philips Children's Medical Ventures, Monroeville, PA, USA). The STB was measured in triplicate by spectrophotometry (Apel BR 5100, APEL, Japan). Bland and Altman plots were drawn to determine agreement between the TcBs and STB.

RESULTS

The gestation and birth weight of enrolled neonates were 37.0 (1.0) weeks and 2750 (458) g, respectively. The age at initiation and duration of PT were 75 (27 to 312) and 25.3 (4.4) h, respectively. Bland and Altman plot showed poor agreement between TcBs and STB at all time points. The gradient (median, range) between TcBs and STB at 0, 12, 24 h and 12 h after cessation of PT were -0.2 (-4.9 to 3.5), 1.4 (-4.7 to 4.0), 1.5 (-3.8 to 9.4) and 2 (-2.9 to 5.8) mg dl^-1. The proportions of TcBs values outside ±1.5 mg dl^-1 of STB ranged from 47 to 64% at four time points.

CONCLUSION

TcBs does not appear to be reliable for estimating serum bilirubin in late preterm and term neonates receiving PT.

Diagnosis Accuracy of Transcutaneous Bilirubinometry in Very Preterm Newborns

BACKGROUND

Transcutaneous bilirubin (TcB) is a validated test for systematic screening of neonatal hyperbilirubinemia and monitoring term and near-term infants under phototherapy.

OBJECTIVES

To evaluate TcB diagnostic accuracy for very preterm neonates.

METHODS

Total serum bilirubin (TSB) and TcB measurements were performed prospectively in a multicenter sample of newborns <30 weeks of gestational age (GA). TcB sensitivity, specificity, predictive values, and likelihood ratios for the detection of neonates requiring phototherapy were calculated over the first 15 days of life, with or without phototherapy, with the expectation of achieving a detection rate of hyperbilirubinemia of over 95%. The potential influence of neonatal characteristics on the discordance between TcB and TSB in very preterm newborns was analyzed using multivariate multilevel logistic regression analyses.

RESULTS

Altogether, 481 measurements were analyzed in 167 preterm patients. Mean GA was 27.6 ± 1.6 weeks. The rates of newborns requiring phototherapy were 52% in the first 3 days, 16% from the 4th to the 7th day, and 2% during the second week. Diagnostic performance was similar among babies with or without phototherapy. TcB sensitivity decreased over time from 100% (93.9-100.0) to 50% (1.3-98.7). Specificity showed an inverse evolution from 14.8% (7.0-26.2) to 80.7% (72.2-89.2). The best performance was that of negative predictive values which varied from 95.5 to 100.0. False negatives were rare throughout the study (0.8% of measurements). In a multivariate analysis, the only factor significantly influencing discordance between TcB and TSB was postnatal age. We did not find any impact of GA and skin color.

CONCLUSION

Among very preterm babies, TcB measurements might be useful for screening for neonatal jaundice in the first 2 weeks of life. In case of a TcB value below the phototherapy threshold, invasive TSB quantification could be unnecessary, with potential avoidance of blood drawing.

Clinical utility of transcutaneous bilirubinometer (TcB) in very low birth weight (VLBW) infants

OBJECTIVE

This is a comprehensive study designed to evaluate the clinical usefulness of transcutaneous bilirubinometry (TcB) in very low birth weight (VLBW) newborns of African American (AA) descent.

METHODS

TcB was conducted at the anterior superior iliac spine (ASIS), temporal region and sternum within 2 h of total serum bilirubin (TSB) measurements in newborns born at ≤32 weeks' gestation prospectively. Average (AVG) TcB levels were also calculated. The relationships between TSB and TcB levels were analyzed using non-parametric Spearman bivariate correlations, a Bland-Altman plot procedure and a decision tree (DT) analysis.

RESULTS

One hundred newborns and 555 TSB data points were available. Eighty-nine percent of the newborns were AA. A significant correlation (P<0.0001) was observed between TSB and TcB values obtained at the ASIS (r=0.73), sternum (0.73), temporal region (0.61) and AVG (0.77). The Bland-Altman plot revealed a good agreement between AVG TcB values and TSB values. A DT analysis indicated that AVG TcB was also found to be the most significant predictor of TSB values in both the no phototherapy (PT) and biliblanket subgroups.

CONCLUSION

TcB can be used reliably in VLBW AA newborns in the absence of overhead PT. The use of TcB in monitoring jaundice in VLBW newborns would help decrease the number of blood draws and cost of care.

Utility of Decision Rules for Transcutaneous Bilirubin Measurements

BACKGROUND

Transcutaneous bilirubin (TcB) meters are widely used for screening newborns for jaundice, with a total serum bilirubin (TSB) measurement indicated when the TcB value is classified as "positive" by using a decision rule. The goal of our study was to assess the clinical utility of 3 recommended TcB screening decision rules.

METHODS

Paired TcB/TSB measurements were collected at 34 newborn nursery sites. At 27 sites (sample 1), newborns were routinely screened with a TcB measurement. For sample 2, sites that typically screen with TSB levels also obtained a TcB measurement for the study. Three decision rules to define a positive TcB measurement were evaluated: ≥75th percentile on the Bhutani nomogram, 70% of the phototherapy level, and within 3 mg/dL of the phototherapy threshold. The primary outcome was a TSB level at/above the phototherapy threshold. The rate of false-negative TcB screens and percentage of blood draws avoided were calculated for each decision rule.

RESULTS

For sample 1, data were analyzed on 911 paired TcB-TSB measurements from a total of 8316 TcB measurements. False-negative rates were <10% with all decision rules; none identified all 31 newborns with a TSB level at/above the phototherapy threshold. The percentage of blood draws avoided ranged from 79.4% to 90.7%. In sample 2, each rule correctly identified all 8 newborns with TSB levels at/above the phototherapy threshold.

CONCLUSIONS

Although all of the decision rules can be used effectively to screen newborns for jaundice, each will "miss" some infants with a TSB level at/above the phototherapy threshold.

Transcutaneous bilirubin levels in newborns <35 weeks' gestation

OBJECTIVE

In infants <35 weeks' gestation, we sought to define the transcutaneous bilirubin (TcB) levels at which a total serum bilirubin (TSB) level suggesting the need for phototherapy is unlikely to occur and a TSB measurement can, therefore, be avoided.

STUDY DESIGN

Nursing staff performed 896 TcB measurements within 1 h of a TSB on 225 neonates 26 0/7-34 6/7 weeks' postmenstrual age (PMA). Generalized linear models were fit with generalized estimating equations (GEEs) to model the probability of having a TSB level at or above the phototherapy initiation cutpoint as a function of the TcB; these methods allow for multiple tests per infant.

RESULTS

The mean difference between TcB and TSB measurements was <1 mg dl(-1) for each PMA category. When the TcB was at least 3 mg dl(-1) below the TSB cutpoint for phototherapy, there was a ⩾98% probability that the TSB was not at, or above, the recommended phototherapy level. The single exception to this was a phototherapy level of 6 mg dl(-1) for infants of 28 0/7-29 6/7 weeks' PMA, where a TcB of 4 mg dl(-1) below the phototherapy level (ie a TcB ⩽2 mg dl(-1)) was necessary to achieve ⩾98% probability.

CONCLUSION

Our data support the use of routine TcB screening for infants 28-34 6/7 weeks' gestation. TcB screening in the neonatal intensive care unit can identify infants who require a TSB to confirm or exclude the need for phototherapy.

Discrepancies between transcutaneous and serum bilirubin measurements

OBJECTIVE

To characterize discrepancies between transcutaneous bilirubin (TcB) measurements and total serum bilirubin (TSB) levels among newborns receiving care at multiple nursery sites across the United States.

METHODS

Medical records were reviewed to obtain data on all TcB measurements collected during two 2-week periods on neonates admitted to participating newborn nurseries. Data on TSB levels obtained within 2 hours of a TcB measurement were also abstracted. TcB--TSB differences and correlations between the values were determined. Data on demographic information for individual newborns and TcB screening practices for each nursery were also collected. Multivariate regression analysis was used to identify characteristics independently associated with the TcB--TSB difference.

RESULTS

Data on 8319 TcB measurements were collected at 27 nursery sites; 925 TSB levels were matched to a TcB value. The mean TcB--TSB difference was 0.84 ± 1.78 mg/dL, and the correlation between paired measurements was 0.78. In the multivariate analysis, TcB--TSB differences were 0.67 mg/dL higher in African-American newborns than in neonates of other races (P < .001). The TcB--TSB difference also varied significantly based on brand of TcB meter used and hour of age of the infant. For 2.2% of paired measurements, the TcB measurement underestimated the TSB level by ≥ 3 mg/dL.

CONCLUSIONS

During routine clinical care, TcB measurement provided a reasonable estimate of TSB levels in healthy newborns. Discrepancies between TcB and TSB levels were increased in African-American newborns and varied based on brand of meter used.

Transcutaneous bilirubinometry

Although the modern era of transcutaneous bilirubin monitoring (TcB) began only about 35 years ago, this screening tool is now widely used in newborn nurseries and outpatient clinics, offices, and emergency departments to obtain a rapid and non-invasive estimate of the degree of hyperbilirubinemia. TcB devices have become more sophisticated, and major breakthroughs include the following: (a) ability to report a bilirubin value rather than an index value, (b) enhanced correction for chromophores other than bilirubin, and (c) technologic improvements including interface with electronic medical records. Good agreement with laboratory bilirubin measurement has been demonstrated, and the ability of TcB screening to predict and decrease the incidence of subsequent hyperbilirubinemia has been well-documented. To date, it has not been shown that this screening results in improved long-term outcomes.

Correlation of transcutaneous bilirubinometry (TcB) and total serum bilirubin (TsB) levels after phototherapy

AIM

To investigate the correlation between transcutaneous bilirubinometry (TcB) and total serum bilirubin (TsB) in jaundiced infants before and after, but not during phototherapy.

METHODS

This study prospectively investigated the correlation between TcB and TsB in term and near term infants before and after phototherapy.

RESULTS

Overall 673 pairs of measurements (TcB and TsB) were performed on 371 infants of ≥35 weeks gestation and with birth weight above 2000 g. Of these 337 sets were from 200 infants who had not been treated with phototherapy (Group 1) and 336 measurements from 171 infants taken between 1 h and 5 d after phototherapy (Group 2). The correlation coefficient between TcB and TsB in the whole cohort was r = 0.72. The correlation was low during the first 8 h after phototherapy (r = 0.56), but thereafter the correlation returned to the range of 0.65-0.8. Using the Sobel test, no significant difference was found between the correlation coefficients at the different time periods, with the possible exception of the difference between 1 and 8 h and 9 and 16 h which was of borderline significance with a p value of 0.06.

CONCLUSION

This study demonstrates good correlation between TcB and TsB by 8 h after phototherapy. This adds validity to community-based screening programs employing TcB measurements plotted on TsB nomograms. Such programs may contribute to prevention of tragic cases of bilirubin-induced neurologic damage.

Influence of assessment site in measuring transcutaneous bilirubin

OBJECTIVE

To investigate the influence of the site of measurement of transcutaneous bilirubin (forehead or sternum) in reproducibility of results as compared to plasma bilirubin.

METHODS

A cohort study including 58 term newborns with no hemolytic disease. Transcutaneous measurements were performed on the forehead (halfway between the headline and the glabella, from the left toward the right side, making consecutive determinations, one-centimeter apart) and the sternum (five measurements, from the suprasternal notch to the xiphoid process with consecutive determinations, one-centimeter apart) using Bilicheck® (SpectRx Inc, Norcross, Georgia, USA). The correlation and agreement between both methods and plasma bilirubin were calculated.

RESULTS

There was a strong linear correlation between both determinations of serum bilirubin at the forehead and sternum (r=0.704; p<0.01 and r=0.653; p<0.01, respectively). There was correspondence of the mean values of transcutaneous bilirubin measured on the sternum (9.9 ± 2.2mg/dL) compared to plasma levels (10.2 ± 1.7 mg/dL), but both differ from the values measured on the forehead (8.6 ± 2 .0mg/dL), p<0.05.

CONCLUSION

In newborn term infants with no hemolytic disease, measuring of transcutaneous bilirubin on the sternum had higher accuracy as compared to serum bilirubin measurement on the forehead.

Comparison of the transcutaneous bilirubinometers BiliCheck and Minolta JM-103 in preterm neonates

AIM

To investigate the trueness and uncertainty of two transcutaneous bilirubinometers BiliCheck and Minolta JM-103 in preterm infants; establish cut-off values for the transcutaneous bilirubin (TcB) level, indicating the need for total serum bilirubin (TsB) measurement; and estimate how many blood samples could be saved.

METHODS

In 133 neonates with gestational ages 28(+0) -34(+6) weeks, 239 measurements of TcB by BiliCheck (TcB(B)) and JM-103 (TcB(M)) and of TsB were performed.

RESULTS

Median TsB of the first samples was 160 (range, 53-293) μmol/L, whereas median TcB(B) was 12 μmol/L (8%) lower and TcB(M) 67 μmol/L (40%) lower. TcB(B) underestimated TsB for TsB ≥180μmol/L. All TcB(M) values, except one, underestimated TsB. The underestimation increased with increasing TsB. Multiple regression analysis showed that post-natal age and ethnicity were confounding factors for TcB(M); none were found for TcB(B). The uncertainty was the same for the two instruments. By using cut-off values of 70% of the phototherapy limit for TcB(B) and 35% for TcB(M), the sensitivity of the screening would be 95% and 97%, and 36% and 24% of the blood samples could be saved, respectively.

CONCLUSION

TcB determined with JM-103 gave values much lower than those obtained with BiliCheck. The underestimation of TsB increased with increasing concentrations. By using transcutaneous bilirubinometers in preterm neonates, 24-36% of the blood samples could be saved.

Severe neonatal jaundice: is it a rare event in Australia?

Hyperbilirubinaemia is common in the newborn period, and while the vast majority of babies are unaffected, significant neurological impairment remains a risk associated with extremely high levels of bilirubin. There is concern internationally that the number of babies affected by severe neonatal hyperbilirubinaemia may be increasing. This review describes the most current published data pertaining to the incidence and causes of severe neonatal hyperbilirubinaemia in order to determine whether concern regarding the possible re-emergence of kernicterus in Australia is warranted. Seven incidence studies conducted internationally between 1988 and 2005 identify an estimated incidence of severe neonatal jaundice of between 7.1 and 45 per 100,000 births and of kernicterus at 0.4-2.7. Major pathophysiological causes or associations include ABO and other blood group incompatibility, glucose-6-phoshate-dehydrogenase deficiency, infection and haemolysis of other causes including spherocytosis. Other factors associated with poor outcomes include prematurity, male gender, ethnicity, breastfeeding and early hospital discharge. The management of severe neonatal jaundice requires multifaceted risk quantification in addition to the availability of adequate surveillance, particularly in the context of early hospital discharge. It is of concern that currently there is a paucity of incidence data in Australia relating to this potentially devastating yet generally preventable condition. Therefore, a surveillance study has been initiated through the Australian Paediatric Surveillance Unit. It is anticipated that these data will accurately define the incidence in Australia and hopefully guide strategies to prevent a condition that we may have prematurely considered to be of historical interest only.

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.

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.

Screening and early postnatal management strategies to prevent hazardous hyperbilirubinemia in newborns of 35 or more weeks of gestation

Although kernicterus is a rare condition, it is still being reported in North America and Western Europe in addition to less developed parts of the world. The majority of affected infants are term and late-preterm newborns who have been discharged from the nursery as 'healthy newborns' yet have subsequently developed extreme hyperbilirubinemia and the classic neurodevelopmental findings associated with kernicterus. Published guidelines provide the basic tools for preventing hazardous hyperbilirubinemia and the two most important of these are a systematic assessment, prior to discharge, of each infant, for the risk of severe hyperbilirubinemia, and appropriate follow-up based on the time of discharge and the risk assessment. The most recent recommendations call for a predischarge measurement of the serum or transcutaneous bilirubin in all infants. When combined with the gestational age and other risk factors for hyperbilirubinemia, this provides the best estimate of the risk, or lack of risk, for subsequent hyperbilirubinemia, and determines the timing of follow-up and the need for further evaluation and treatment. The application of these principles to the management of the jaundiced newborn might not eliminate every case of kernicterus, but should contribute to a reduction in its occurrence.

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.

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).

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.

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.

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.

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.

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.

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.

Transcutaneous bilirubin in predicting hyperbilirubinemia in term neonates

OBJECTIVE

To assess the utility of 24 and 48 hours transcutaneous bilirubin (TcB) index for predicting subsequent significant hyperbilirubinemia in healthy term neonates.

METHODS

TcB indices were obtained for healthy, breastfed, term AGA newborns at 24 +/- 2, 48 +/- 2 and subsequently at intervals of 24 hours. Neonates with illness, on treatment and positive Direct Coomb's test were excluded. Serum bilirubin levels were obtained whenever indicated. Neonates having serum bilirubin > or = 17 mg/dL were considered as significant hyperbilirubinemia. The 24 and 48 hour TcB indices, as risk predictors for such hyperbilirubinemia were determined.

RESULTS

Study included 461 healthy term neonates. The mean birth weight was 2949 (+/- 390) gm and mean gestation of 38.6 (+/- 1.1) weeks. Eight one (17.6%) had significant hyperbilirubinemia. Of 461, 135 (29.3%) had TcB index.

CONCLUSION

The 24 and 48 hour TcB indices are predictive for subsequent significant hyperbilirubinemia and can guide clinician in early discharge of healthy term newborns.

Using BiliCheck for preterm neonates in a sub-intensive unit: diagnostic usefulness and suitability

BACKGROUND

BiliCheck (BC), a new transcutaneous bilirubinometer is thought to be lacking in the disadvantages of old devices and could be potentially useful for diagnosing jaundice in preterm babies. Although its accuracy is well known in healthy term babies, there is a lack of knowledge about its usefulness in preterm infants.

AIMS

To investigate BC usefulness in preterm babies and its suitability in a sub-intensive neonatal unit.

STUDY DESIGN

In 340 preterm infants between 30 and 36 weeks of gestational age, transcutaneous and serum bilirubin measurement were performed. Hematocrit, pH, postnatal age, gestational age, and sex were also studied to clarify their influence on BC accuracy. For a subset of 100 neonates transcutaneous measurement, blood collection and serum analysis were timed and costs were considered.

RESULTS

Correlation coefficient is 0.795 (p<0.001) and this is not affected by factors previously supposed to be important. Overall sensitivity was 100% and specificity were comprised between 40% and 72%. BC has a tendency to overestimate serum bilirubin, at high values. Considering the whole time for serum bilirubin measurement, transcutaneous bilirubinometry is a faster (p<0.0001), but more expensive technique with a cost of about 5 euro/measurement. Nevertheless, using BC as a screening-device we could safely avoid 58-79% of blood samples, since its positive predictive values is about 21-42%. This would allow to a cost reduction of 1555-2120 euro/year.

CONCLUSIONS

BC has a good reliability in preterm infants although not as good as in healthy term babies. BC is a time-sparing tool and can improve the management of neonatal jaundice in preterm infants; however, its tendency to overestimate suggests its use only for screening purposes.

[Transcutaneous bilirubin measurement in preterm infants]

Transcutaneous bilirubinometry is an effective screening tool for neonatal jaundice in full-term babies. But its accuracy is not shown yet in preterm infants.

METHODOLOGY

We carried out a prospective study in a neonatal intensive care unit. The study included 47 preterm infants. From birth, a transcutaneous bilirubin measurement (BTc) using the BiliCheck was made on the forehead of each newborn every 8 h. Blood sampling for determination of total serum bilirubin (BS) was combined with BTc: 1) if value of BTc was higher than limits values for phototherapy; 2) on the second day of life and 3) 4 hours after cessation of phototherapy.

RESULTS

Mean gestational age was 30 week and mean birth weight was 1419 g. We studied 151 pairs of BTc and BS. Mean values obtained by BTc and BS were respectively 160.6+/-50 mumol/L and 190.6+/-61.4 mumol/L. A significant correlation between BTc and BS was found. But the limits of agreement were very wide. The negative predictive value (NPV) of BTc was above 90% in each group of gestational age.

DISCUSSION

The need for phototherapy cannot be determined by BTc in preterm infants. But the BTc is reliable when its value is under the limits for phototherapy.

CONCLUSION

With a very high incidence of neonatal jaundice (87%) in our cohort, a value of BTc under the limits for phototherapy has a good NPV in preterm infants.