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

The use of a simple and affordable skin patch for measurement of transcutaneous bilirubin levels in neonates during phototherapy

Background

Transcutaneous bilirubin (TcB) measurements during and after phototherapy for hyperbilirubinemia must be performed on unexposed skin. There are commercially made skin patches for this purpose, but they are relatively unavailable in low-resource settings. We devised a simple cotton patch and tested its use for TcB during phototherapy.

Methods

Measurements were taken in healthy neonates born at a gestational age of ≥35 weeks who were undergoing phototherapy for hyperbilirubinemia in western India before, 12 h after the start, and 12 h after the end of phototherapy. Total serum bilirubin (TSB) was measured using the diazo method in a clinical laboratory. TcB measurements were performed using a Dräger Jaundice Meter JM-105 placed over the sternum on two skin areas that were protected during and after treatment by a commercial (Philips BilEclipse) or self-made patch comprised of cotton gauze and wool.

Results

In total, 47 neonates were included in our study. Before phototherapy, TSB and TcB values had a strong correlation (Pearson, r = 0.88), with a mean difference of -1.35 mg/dl. Correlations with TSB were good and equivalent for TcB values measured on skin covered by the commercial and self-made patches during (0.78 and 0.70, respectively) and after (0.57 and 0.58, respectively) phototherapy. TcB values measured on skin covered by the two patches correlated well both during and after phototherapy, with r = 0.82 and 0.90, respectively, and mean (95% confidence interval) differences of -1.21 and -0.32 mg/dl, respectively.

Conclusions

Reliable TcB measurements taken during and after phototherapy can be achieved on skin covered with a simple and affordable cotton skin patch.

Transcutaneous bilirubin reliability during and after phototherapy depending on skin color

Measurement of transcutaneous bilirubin (TcB) is a non-invasive, widely used technique to estimate serum bilirubin (SB). However, its reliability in multiethnic populations during and after phototherapy is still controversial even in covered skin. The aim of this study was to determine the reliability of TcB in covered (cTcB) and exposed (eTcB) skin during and after phototherapy in a multiethnic population of term and preterm neonates according to Neomar's neonatal skin color scale. Prospective, observational study comparing SB and TcB. We determined SB when clinically indicated and, at the same time, measured cTcB under a photo-opaque patch and eTcB next to it with a jaundice meter (Dräger JM-105TM). All dyads TcB-SB were compared, both globally and according to skin color. We obtained data from 200 newborns (color1: 44, color2: 111, color3: 41, color4: 4) and compared 296 dyads TcB/SB. Correlation between cTcB and SB is strong during (0.74-0.83) and after (0.79-0.88) phototherapy, both globally and by color group. The SB-cTcB bias depends on gestational age during phototherapy and on skin color following phototherapy. The correlation between eTcB and SB during phototherapy is not strong (0.54), but becomes so 12 h after discontinuing phototherapy (0.78).  Conclusions: Our study supports the reliability of cTcB to assess SB during and after phototherapy, with differences among skin tones after the treatment. The use of cTcB and Neomar's scale during and mainly after phototherapy may help reduce the number of blood samples required. What is Known: • Controversies exist on the reliability of jaundice meters during and after phototherapy in covered skin. Only a few studies have analyzed their accuracy in multiethnic populations, but none has used a validated neonatal skin color scale. What is New: • We verified correlation between serum and transcutaneous bilirubin in covered skin in a multiethnic population depending on skin color based on our own validated neonatal skin color scale during and after phototherapy.

Machine Learning to Improve Accuracy of Transcutaneous Bilirubinometry

INTRODUCTION

This study aimed to develop models for predicting total serum bilirubin by correcting errors of transcutaneous bilirubin using machine learning based on neonatal biomarkers that could affect spectrophotometric measurements of tissue bilirubin.

METHODS

This retrospective study included infants born at our hospital (≥36 weeks old, ≥2,000 g) between January 2020 and December 2022. Infants without a phototherapy history were included. Robust linear regression, gradient boosting tree, and neural networks were used for machine learning models. A neural network, inspired by the structure of the human brain, was designed comprising three layers: input, intermediate, and output.

RESULTS

Totally, 683 infants were included. The mean (minimum-maximum) gestational age, birth weight, participant age, total serum bilirubin, and transcutaneous bilirubin were 39.0 (36.0-42.0) weeks, 3,004 (2,004-4,484) g, 2.8 (1-6) days of age, 8.50 (2.67-18.12) mg/dL, and 7.8 (1.1-18.1) mg/dL, respectively. The neural network model had a root mean square error of 1.03 mg/dL and a mean absolute error of 0.80 mg/dL in cross-validation data. These values were 0.37 mg/dL and 0.28 mg/dL, smaller compared to transcutaneous bilirubin, respectively. The 95% limit of agreement between the neural network estimation and total serum bilirubin was -2.01 to 2.01 mg/dL. Unnecessary blood draws could be reduced by up to 78%.

CONCLUSION

Using machine learning with transcutaneous bilirubin, total serum bilirubin estimation error was reduced by 25%. This integration could increase accuracy, lessen infant discomfort, and simplify procedures, offering a smart alternative to blood draws by accurately estimating phototherapy thresholds.

Transcutaneous Bilirubin Accuracy Before, During, and After Phototherapy: A Meta-Analysis

CONTEXT

Transcutaneous bilirubinometry (TcB) is used as a valid screening to identify neonates requiring measurement of total serum bilirubin (TSB) before phototherapy. Its use during and after phototherapy is not advised yet because of unknown reliability.

OBJECTIVES

To determine the agreement of TcB and TSB measurements before, during, and after phototherapy.

DATA SOURCES

PubMed Medline, Cochrane Library, and references of eligible studies were searched.

STUDY SELECTION

Prospective and retrospective cohort and cross-sectional studies reporting Bland-Altman statistics of paired TcB and TSB measurements in term and preterm newborns.

DATA EXTRACTION

Meta-analysis was performed using the Mantel-Haenszel weighted approach. The agreement between TcB and TSB in μmol/L was described by pooled mean differences (MDs) and limits of agreement (LoA).

RESULTS

Fifty-four studies were included. The pooled MD before phototherapy is 2.5 μmol/L (LoA -38.3 to 43.3). The pooled MD during phototherapy is -0.3 μmol/L (LoA -34.8 to 34.2) on covered skin and -28.6 μmol/L (LoA -105.7 to 48.5) on uncovered skin. The pooled MD after phototherapy is -34.3 μmol/L (LoA -86.7 to 18.1) on covered skin and -21.1 μmol/L (LoA -88.6 to 46.4) on uncovered skin. Subgroup analysis revealed the best agreement at the forehead. We did not find any difference in agreement between term and preterm neonates.

LIMITATIONS

Language restriction.

CONCLUSIONS

TcB measurements before and during phototherapy on covered skin show good agreement compared with TSB in term and preterm newborns. More studies are needed to evaluate the accuracy after phototherapy.

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.

Transcutaneous bilirubin measured on protected skin during phototherapy in term and preterm neonates

BACKGROUND

Transcutaneous bilirubin (TCB) measurement is a simple, painless, and time-saving alternative for the assessment of TSB (total serum bilirubin) levels. However, TCB measurements obtained during phototherapy can yield inaccurate results. We evaluated the effectiveness of TCB measurements obtained from protected skin areas in patients who underwent phototherapy.

METHODS

This prospective study included neonates delivered at a gestational age of ≥340/7 weeks. TCB measurements were performed at the forehead and the lower end of the sternum using a JM-105 device. Simultaneously, blood samples were collected to determine TSB levels. During phototherapy, the forehead was covered with a photo-opaque patch. TSB and TCB were measured before, during, at the end of, and after phototherapy.

RESULTS

In total, 200 neonates, including 110 (55 %) term and 90 (45 %) late preterm infants, were enrolled. Of these neonates, 162 (81 %) were Turkish while 38 (19 %) were refugees from Syria and Iraq. Notably, no statistically significant differences were observed in the TSB and TCB values between the Turkish and refugee groups (p > 0.05). Bland-Altman analysis was conducted between the TCB values obtained from the covered forehead area and TSB values; the analysis revealed moderate, high, and excellent agreements for the first bilirubin measurement and at the end of phototherapy, before phototherapy, and for the second and rebound bilirubin measurements, respectively. Regarding intraclass correlation coefficients, values >0.95, 0.94-0.85, 0.84-0.70, and < 0.7 indicated perfect, high, moderate, and unacceptable compatibilities, respectively. Although a significant association was observed between pre-phototherapy TCB obtained from the sternum and TSB levels, no significant associations were observed during phototherapy.

CONCLUSIONS

Our findings indicate that the consistency observed between TCB measurements obtained from the protected skin areas and TSB values can be used to monitor phototherapy effectiveness, particularly in late preterm/term infants and those with darker skin tones. Furthermore, this approach can aid in guiding decisions related to treatment termination, evaluating rebound bilirubin levels, minimizing costs, and providing a less invasive testing option.

Noninvasive transcutaneous bilirubin measurement in adults using skin diffuse reflectance

Accurate measurement of bilirubin concentration in adults is crucial for the diagnosis and management of liver and biliary tract diseases. Traditional methods relying on central laboratory testing pose challenges such as invasiveness, patient discomfort, and time consumption. Non-invasive alternatives have been explored, but their applicability to adult populations remains uncertain. This study aimed to develop and validate a portable non-invasive optical system based on spatially resolved diffuse reflectance spectroscopy (DRS) specifically tailored for adult transcutaneous bilirubin measurement. Forty-two adult patients with various underlying conditions were included in the study. Comparisons between transcutaneous bilirubin values measured by the DRS system and total serum bilirubin concentrations obtained through blood tests revealed strong correlations, particularly at the neck (r = 0.872) and the medial side of the right upper arm (r = 0.940). Bland-Altman analyses demonstrated substantial agreement between the transcutaneous bilirubin values and total serum bilirubin concentrations. The results highlight the potential of the non-invasive DRS system as a convenient and reliable tool for monitoring bilirubin values in adults.

The Accuracy of Transcutaneous Bilirubin as a Screening Test in Preterm Infants

OBJECTIVE

To determine the accuracy of transcutaneous bilirubin (TcB) to predict total serum bilirubin (TSB) in preterm infants across gestational age (GA) ranges and to calculate the cost-effectiveness of TcB as the primary screening test of choice for neonatal jaundice in neonatal intensive care unit (NICU) settings.

METHODS

Single-center retrospective study of infants aged ≤ seven days admitted to the NICU over a six-month period with a paired TSB and TcB, with or without phototherapy as part of their routine clinical care. Infants were divided into GA-specific groups as term, late preterm, moderate preterm, and very preterm. Measurement bias (bias=TSB-TcB) was calculated on the paired TSB and TcB values, and a Bland-Altman analysis was carried out. The impacts of additional infant-specific variables on the bias were assessed with univariate and multivariate linear regression techniques. The potential direct cost savings associated with the use of TcB as the primary screening test were calculated.

RESULTS

A total of 263 paired TSB and TcB samples from 95 patients were included (130 paired samples from term (n=60), 75 from late preterm (n=21), 27 from moderate preterm (n=7), and 31 from very preterm (n=7)). The mean paired measurement bias across all the GA groups was -0.9 ± 2.9 mg/dL. The sensitivity and specificity of TcB in GA < 35 weeks were 92% and 62%, respectively. A conservative estimate of a one-third reduction in TSB measurement by using TcB as the primary screening test will have a direct cost saving of $3,148 over a six-month period.

CONCLUSION

Our data suggest that TcB is a safe and potentially cost-effective screening test for jaundice across GA groups.

Transcutaneous bilirubin levels in extremely preterm infants less than 30 weeks gestation

OBJECTIVE

The primary objective of this study was to determine the relationship between transcutaneous bilirubin (TcB) levels and total serum bilirubin (TSB) levels in extremely preterm infants.

STUDY DESIGN

We conducted a prospective multicenter study of extremely preterm infants less than 30 weeks gestation in California. Difference between paired TcB and TSB values were compared based on gestational age, birth weight, maternal race/ethnicity, chronological age as well as during and after phototherapy.

RESULTS

TSB values ranged from 0 to 12.6 mg/dl and the TcB values ranged from 0 to 14.2 mg/dl. TSB was predicted with a high degree of accuracy at TSB = 2.37 + 0.54 (TcB) with r = 0.786. There was good correlation across gestational age, birth weight, race/ethnic, chronological age subgroups as well as during and after phototherapy.

CONCLUSION

Our study supports the use of TcB as a screening tool for monitoring jaundice in extremely preterm infants.

A Comparison Between Transcutaneous Bilirubin and Total Serum Bilirubin Levels for the Management of Jaundice in Preterm Neonates by Bland-Altman Plot

Objective

To compare the bilirubin levels measured by transcutaneous bilirubinometer and serum samples for the management of jaundice in preterm neonates.

Methods

The study was a prospective comparative observational study conducted in a tertiary care neonatal unit of Odisha from January 2019 to June 2020. All inborn and outborn neonates with a gestational age of 28^0/7 weeks to 36^6/7 weeks with the clinical diagnosis of neonatal jaundice were included in the study. Transcutaneous bilirubin (TcB) was estimated by Dragger jaundice meter JM-105 and simultaneously venous blood and total serum bilirubin levels (TSB) were measured by diazonium method. The comparison between TcB and TSB values was analyzed by direct linear correlation in scatter plot and Bland-Altman plot.

Results

A total of 167 preterm neonates (66, 28-33^6/7 and 111, 34-36^6/7), with a mean gestational age 33.55 ±2.36 weeks and a mean birth weight of 1960 ± 613 grams, were analyzed. The mean TSB and TcB levels were 12.99 ± 3.47 mg/dl (min-max 4.9-18.3 mg/dl) and 14.156 ± 4.71 mg/dl (min-max 4-20.1 mg/dL), respectively. The TcB is excellently correlated with TSB with a correlation coefficient of r =0.948, p ≤0.001. The bias difference between TcB and TSB is -1.16 (95% CI: 2.35, -4.6) mg/dl. The correlation coefficients between 28-33^6/7 weeks gestational age groups (r = 0.944) and 34-36^6/7gestational age (r = 0.950) were similar.

Conclusion

TcB is well correlated with TSB level in preterm neonates. Hence, TcB can be used for the guidance of management in these neonates.

Efficacy of transcutaneous bilirubinometry as compared to serum bilirubin in preterm newborn during phototherapy

Transcutaneous measurement of bilirubin is being used for neonatal jaundice. Its utility during phototherapy in preterm babies is not established. The objective of our study was to assess the efficacy of transcutaneous bilirubin (TcB) measurement in comparison to total serum bilirubin in preterm newborns at admission and during phototherapy at the covered skin area (glabella). It was a prospective observational study and conducted at the neonatal intensive care unit of a tertiary care hospital from January 2017 to January 2019. One hundred eligible preterm neonates were enrolled. Babies who were very sick, with poor peripheral circulation, edematous, having conjugated hyperbilirubinemia, with major congenital malformations, already received phototherapy or exchange transfusion were excluded. Paired total serum bilirubin and transcutaneous bilirubin were measured at admission and 6 h and 24 h during phototherapy. TcB was measured from the area (glabella) covered by an eye protector during phototherapy. The sample for TsB was taken within 10 min of TcB measurement. The mean differences between TsB and TcB values at admission and 6 h and 24 h of phototherapy were - 0.005 (0.353) mg/dl, - 0.350 (0.611) mg/dl, and - 0.592 (0.353) mg/dl, respectively. At admission or before starting of phototherapy, the difference (TsB-TcB) was statistically not significant (p = .125), while the difference in these values was statistically significant at 6 h and 24 h of phototherapy.Conclusion: TcB measurements from the covered skin area in jaundiced preterm infants during phototherapy were not correlated with TsB and cannot be used as an alternate of serum bilirubin testing. What is known • HPLC bilirubin measurement is a gold standard test for bilirubin measurement but impractical for day to day use. Serum total bilirubin is used for clinical testing.. • There is evidence for use of transcutaneous bilirubinometry for assessment of bilirubin in term newborn. What is new • TcB measurements from a covered skin area in jaundiced preterm newborns under phototherapy were not correlated significantly at 6 h and 24 h of phototherapy, but correlated before phototherapy. • TcB cannot be used as an alternate of serum bilirubin testing in preterm infants during phototherapy.

Accuracy of enhanced transcutaneous bilirubinometry according to various measurement sites

Objective

The goal of the study was to provide missing data on the accuracy of enhanced transcutaneous bilirubinometry in a monoracial population of term neonates, considering three different measurement sites.

Material and Methods

Transcutaneous bilirubin was measured using the JM-105 device on the forehead, chest, and abdomen. Blood sampling for total serum bilirubin concentration has been performed within 10 minutes of transcutaneous measurements. Paired transcutaneous bilirubin and total serum bilirubin measurements were statistically analyzed.

Results

The study group consisted of 102 healthy term Slovak infants. The correlation between total serum bilirubin and transcutaneous bilirubin was significant (coefficient of determination R2: 0.9045 forehead, 0.8808 sternum, 0.8467 abdomen). Transcutaneous measurements underestimated serum bilirubin levels significantly when total serum bilirubin values were higher than 15 mg/dL, irrespective of the site of transcutaneous measurements. The lowest mean difference between total serum bilirubin and transcutaneous bilirubin was identified on the sternum (median: -1.1 mg/dL). The area under the curve was >0.97 and >0.93 for detecting total serum bilirubin levels >10 mg/dL and >13 mg/dL, respectively, for all measurement sites. Transcutaneous measurements on the forehead and sternum provided very high sensitivity, with the best performance at the forehead.

Conclusion

Transcutaneous bilirubinometry using an enhanced device is an accurate, sensitive, and convenient screening method in term Caucasian neonates. Transcutaneous bilirubin measurements on the forehead, sternum, and abdomen are reliable, with the best performance on the forehead. It is necessary to confirm higher transcutaneous bilirubin values with a total serum bilirubin measurement.

Transcutaneous versus Total Serum Bilirubin Measurements in Preterm Infants

INTRODUCTION

Transcutaneous bilirubin (TcB) measurement offers a noninvasive approach for bilirubin screening; however, its accuracy in preterm infants is unclear. This study determined the agreement between TcB and total serum bilirubin (TSB) among preterm infants.

METHODS

A multisite prospective cohort study was conducted at 3 NICUs in Ontario, Canada, September 2016 to June 2018. Among 296 preterm infants born at 240/7 to 356/7 weeks, 856 TcB levels were taken at the forehead, sternum, and before and after the initiation of phototherapy with TSB measurements. Bland-Altman plots and 95% limits of agreement (LOA) expressed agreement between TcB and TSB.

RESULTS

The overall mean TcB-TSB difference was -24.5 μmol/L (95% LOA -103.3 to 54.3), 1.6 μmol/L (95% LOA -73.4 to 76.5) before phototherapy, and -31.1 μmol/L (95% LOA -105.5 to 43.4) after the initiation of phototherapy. The overall mean TcB-TSB difference was -15.2 μmol/L (95% LOA -86.8 to 56.3) at the forehead and -24.4 μmol/L (95% LOA -112.9 to 64.0) at the sternum. The mean TcB-TSB difference was -31.4 μmol/L (95% LOA -95.3 to 32.4) among infants born 24-28 weeks, -25.5 μmol/L (95% LOA -102.7 to 51.8) at 29-32 weeks, and -15.9 μmol/L (95% LOA -107.4 to 75.6) at 33-35 weeks. Measures did not differ by maternal ethnicity.

CONCLUSION

Among preterm infants, TcB may offer a noninvasive, immediate approach to screening for hyperbilirubinemia with more careful use in preterm infants born at <33 weeks' gestation, as TcB approaches treatment thresholds. Its underestimation of TSB after the initiation of phototherapy warrants the use of TSB for clinical decision-making after the initiation of phototherapy.