Reliability of transcutaneous bilirubin devices in preterm infants: a systematic review

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.

Preventive effect of prenatal maternal oral probiotic supplementation on neonatal jaundice (POPS Study): A protocol for the randomised double-blind placebo-controlled clinical trial

INTRODUCTION

Neonatal jaundice is a common and life-threatening health problem in neonates due to overaccumulation of circulating unconjugated bilirubin. Gut flora has a potential influence on bilirubin metabolism. The infant gut microbiome is commonly copied from the maternal gut. During pregnancy, due to changes in dietary habits, hormones and body weight, maternal gut dysbiosis is common, which can be stabilised by probiotics supplementation. However, whether probiotic supplements can reach the baby through the mother and reduce the incidence of neonatal jaundice has not been studied yet. Therefore, we aim to evaluate the effect of prenatal maternal probiotic supplementation on the incidence of neonatal jaundice.

METHODS AND ANALYSIS

This is a randomised double-blind placebo-controlled clinical trial among 94 pregnant women (47 in each group) in a tertiary hospital in Hong Kong. Voluntary eligible participants will be recruited between 28 and 35 weeks of gestation. Computer-generated randomisation and allocation to either the intervention or control group will be carried out. Participants will take either one sachet of Vivomixx (450 billion colony-forming units per sachet) or a placebo per day until 1 week post partum. Neither the study participants nor researchers will know the randomisation and allocation. The intervention will be initiated at 36 weeks of gestation. Neonatal bilirubin level will be measured to determine the primary outcome (hyperbilirubinaemia) while the metagenomic microbiome profile of breast milk and maternal and infant stool samples as well as pregnancy outcomes will be secondary outcomes. Binary logistic and linear regressions will be carried out to assess the association of the microbiome data with different clinical outcomes.

ETHICS AND DISSEMINATION

Ethics approval is obtained from the Joint CUHK-NTEC Clinical Research Ethics Committee, Hong Kong (CREC Ref: 2023.100-T). Findings will be published in peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT06087874.

Comparative analysis of the quantitative point-of-care CareSTART™ total bilirubin with central laboratory total bilirubin assays in neonatal blood samples

This study aimed to assess and compare the accuracy of point-of-care CareSTART™ S1 Total Bilirubin test with a central laboratory total bilirubin assay using neonatal samples. This study was conducted using 152 paired measurements obtained from 122 neonates admitted to the neonatal intensive care unit. Total serum bilirubin (TSB) levels assayed with the central laboratory assay, laboratory bilirubinomter, trancutaneous bliribubin (TcB) instrument and CareSTART were compared using Bland-Altman analysis. The mean difference between the CareSTART and TSB values was -1.43 mg/dL and the 95% limit of agreement (LoA) was -4.25 to 1.39 mg/dL. CareSTART tended to underestimate total bilirubin concentrations compared with TcB, however, the LoA was narrower due to the smaller SD of mean difference for CareSTART. The CareSTART Total Bilirubin test provides an accurate alternative to TcB for total serum bilirubin measurement. Given its low-cost, ease-of-use, and portability, the use of CareSTART is expected to provide point-of-care measurements, especially in low-resource settings.

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.

A review of existing neonatal hyperbilirubinemia guidelines in Indonesia

BACKGROUND

Neonatal hyperbilirubinemia is one of the most common conditions for neonate inpatients. Indonesia faces a major challenge in which different guidelines regarding the management of this condition were present. This study aimed to compare the existing guidelines regarding prevention, diagnosis, treatment and monitoring in order to create the best recommendation for a new hyperbilirubinemia guideline in Indonesia.

METHODS

Through an earlier survey regarding adherence to the neonatal hyperbilirubinemia guideline, we identified that three main guidelines are being used in Indonesia. These were developed by the Indonesian Pediatric Society (IPS), the Ministry of Health (MoH), and World Health Organization (WHO). In this study, we compared factors such as prevention, monitoring, methods for identifying, risk factors in the development of neonatal jaundice, risk factors that increase brain damage, and intervention treatment threshold in the existing guidelines to determine the best recommendations for a new guideline.

RESULTS

The MoH and WHO guidelines allow screening and treatment of hyperbilirubinemia based on visual examination (VE) only. Compared with the MoH and WHO guidelines, risk assessment is comprehensively discussed in the IPS guideline. The MoH guideline recommends further examination of an icteric baby to ensure that the mother has enough milk without measuring the bilirubin level. The MoH guideline recommends referring the baby when it looks yellow on the soles and palms. The WHO and IPS guidelines recommend combining VE with an objective measurement of transcutaneous or serum bilirubin. The threshold to begin phototherapy in the WHO guideline is lower than the IPS guideline while the exchange transfusion threshold in both guidelines are comparably equal.

CONCLUSIONS

The MoH guideline is outdated. MoH and IPS guidelines are causing differences in approaches to the management hyperbilirubinemia. A new, uniform guideline is required.

A review of existing neonatal hyperbilirubinemia guidelines in Indonesia

Background

Neonatal hyperbilirubinemia is one of the most common conditions for neonate inpatients. Indonesia faces a major challenge in which different guidelines regarding the management of this condition were present. This study aimed to compare the existing guidelines regarding prevention, diagnosis, treatment and monitoring in order to create the best recommendation for a new hyperbilirubinemia guideline in Indonesia.

Methods

Through an earlier survey regarding adherence to the neonatal hyperbilirubinemia guideline, we identified that three main guidelines are being used in Indonesia. These were developed by the Indonesian Pediatric Society (IPS), the Ministry of Health (MoH), and World Health Organization (WHO). In this study, we compared factors such as prevention, monitoring, methods for identifying, risk factors in the development of neonatal jaundice, risk factors that increase brain damage, and intervention treatment threshold in the existing guidelines to determine the best recommendations for a new guideline.

Results

The MoH and WHO guidelines allow screening and treatment of hyperbilirubinemia based on visual examination (VE) only. Compared with the MoH and WHO guidelines, risk assessment is comprehensively discussed in the IPS guideline. The MoH guideline recommends further examination of an icteric baby to ensure that the mother has enough milk without measuring the bilirubin level. The MoH guideline recommends referring the baby when it looks yellow on the soles and palms. The WHO and IPS guidelines recommend combining VE with an objective measurement of transcutaneous or serum bilirubin. The threshold to begin phototherapy in the WHO guideline is lower than the IPS guideline while the exchange transfusion threshold in both guidelines are comparably equal.

Conclusions

The MoH guideline is outdated. MoH and IPS guidelines are causing differences in approaches to the management hyperbilirubinemia. A new, uniform guideline is required.

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.

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 bilirubinometry versus total serum bilirubin measurement for newborns

BACKGROUND

Jaundice is a very common condition in newborns, affecting up to 60% of term newborns and 80% of preterm newborns in the first week of life. Jaundice is caused by increased bilirubin in the blood from the breakdown of red blood cells. The gold standard for measuring bilirubin levels is obtaining a blood sample and processing it in a laboratory. However, noninvasive transcutaneous bilirubin (TcB) measurement devices are widely available and used in many settings to estimate total serum bilirubin (TSB) levels.

OBJECTIVES

To determine the diagnostic accuracy of transcutaneous bilirubin measurement for detecting hyperbilirubinaemia in newborns.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL and trial registries up to 18 August 2022. We also checked the reference lists of all included studies and relevant systematic reviews for other potentially eligible studies.

SELECTION CRITERIA

We included cross-sectional and prospective cohort studies that evaluated the accuracy of any TcB device compared to TSB measurement in term or preterm newborn infants (0 to 28 days postnatal age). All included studies provided sufficient data and information to create a 2 × 2 table for the calculation of measures of diagnostic accuracy, including sensitivities and specificities. We excluded studies that only reported correlation coefficients.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the eligibility criteria to all citations from the search and extracted data from the included studies using a standard data extraction form. We summarised the available results narratively and, where possible, we combined study data in a meta-analysis.

MAIN RESULTS

We included 23 studies, involving 5058 participants. All studies had low risk of bias as measured by the QUADAS 2 tool. The studies were conducted in different countries and settings, included newborns of different gestational and postnatal ages, compared various TcB devices (including the JM 101, JM 102, JM 103, BiliChek, Bilitest and JH20-1C) and used different cutoff values for a positive result. In most studies, the TcB measurement was taken from the forehead, sternum, or both. The sensitivity of various TcB cutoff values to detect significant hyperbilirubinaemia ranged from 74% to 100%, and specificity ranged from 18% to 89%.

AUTHORS' CONCLUSIONS

The high sensitivity of TcB to detect hyperbilirubinaemia suggests that TcB devices are reliable screening tests for ruling out hyperbilirubinaemia in newborn infants. Positive test results would require confirmation through serum bilirubin measurement.

Validation of a smartphone-based screening tool (Biliscan) for neonatal jaundice in a multi-ethnic neonatal population

AIM

Neonatal jaundice is an important and prevalent condition that can cause kernicterus and mortality. This study validated a smartphone-based screening application (Biliscan) in detecting neonatal jaundice.

METHODS

A cross-sectional prospective study was conducted at the neonatal unit in a tertiary teaching hospital between August 2020 and October 2021. All babies born at the gestation of 35 weeks and above with clinical jaundice or are recommended for screening of jaundice within 21 days of post-natal age were recruited. Using Biliscan, images of the babies' skin over the sternum were taken against a standard colour card. The application uses feature extraction and machine learning regression to estimate the bilirubin level. Independent Biliscan bilirubin estimates (BsB) were made and compared with total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) levels. Bland Altman plots were used to establish the agreement between BsB and TSB, as well as TcB, using the clinically acceptable limits of agreement of ±35 μmol/L, which were defined a priori. Pearson correlation coefficient was assessed to establish the strength of the relationship between BsB versus TSB and TcB. Diagnostic accuracy was assessed through receiver operating characteristic curve analysis.

RESULTS

Sixty-one paired TSB-BsB and 85 paired TcB-BsB measurements were obtained. Bland Altman plot for the entire group showed that 54% (33/61) of the pairs of TSB and BsB readings and 66% (56/85) of the pairs of TcB and BsB readings were within the maximum clinically acceptable difference of 35 μmol/L. Pearson r for BsB versus TSB and TcB was 0.54 (P < 0.001) and 0.66 (P < 0.001) respectively. Compared with TSB, the recommended gold standard measure for jaundice, Biliscan has a sensitivity of 76.92% and specificity of 70.83% for jaundice requiring phototherapy. The positive and negative predictive values in term infants were 93.3% and 36.9%, respectively.

CONCLUSION

Our results suggest that there is moderate correlation and mediocre agreement between BsB and TSB, as well as TcB. Improvement to the application algorithm and further studies that include a larger population, and a wider range of bilirubin values are necessary before the tool may be considered for use in screening of jaundice in newborns.

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.

Current status of neonatal jaundice management in Japan

BACKGROUND

This nationwide survey aimed to determine the status of jaundice management in Japan.

METHODS

A questionnaire about bilirubin level measurements and neonatal jaundice treatment was sent to 330 institutions providing neonatal care. The responses were analyzed according to institution level.

RESULTS

Of 330 institutions, 172 responded (52.1% response rate). Total bilirubin levels were measured in the central laboratory using spectrophotometry at 134 institutions and a blood gas analyzer at 81 institutions. Unbound bilirubin (UB) levels were measured by 79 institutions, while transcutaneous bilirubin measurements were taken at 63 institutions. There was no association between institution level and UB or transcutaneous bilirubin measurement. For phototherapy criteria, the Murata-Imura criteria were adopted by 67 institutions, Nakamura criteria by 36, and Morioka criteria by 39. Light-emitting diodes (LED) were used by 160 institutions versus fluorescent lights by 31. When a blue LED was used, 119 institutions used the high mode. There is no standard for increasing light intensity. No association was found between institution level and phototherapy criteria. UB was measured in 14 of 63 institutions using the Murata-Imura criteria.

CONCLUSIONS

There is a large variation in the management and treatment of neonatal jaundice among institutes in Japan.

Better assessment of neonatal jaundice at home (BEAT Jaundice @home): protocol for a prospective, multicentre diagnostic study

INTRODUCTION

Severe neonatal hyperbilirubinaemia can place a neonate at risk for acute bilirubin encephalopathy and kernicterus spectrum disorder. Early diagnosis is essential to prevent these deleterious sequelae. Currently, screening by visual inspection followed by laboratory-based bilirubin (LBB) quantification is used to identify hyperbilirubinaemia in neonates cared for at home in the Netherlands. However, the reliability of visual inspection is limited. We aim to evaluate the effectiveness of universal transcutaneous bilirubin (TcB) screening as compared with visual inspection to: (1) increase the detection of hyperbilirubinaemia necessitating treatment, and (2) reduce the need for heel pricks to quantify bilirubin levels. In parallel, we will evaluate a smartphone app (Picterus), and a point-of-care device for quantifying total bilirubin (Bilistick) as compared with LBB.

METHODS AND ANALYSIS

We will undertake a multicentre prospective cohort study in nine midwifery practices across the Netherlands. Neonates born at a gestational age of 35 weeks or more are eligible if they: (1) are at home at any time between days 2 and 8 of life; (2) have their first midwife visit prior to postnatal day 6 and (3) did not previously receive phototherapy. TcB and the Picterus app will be used after visual inspection. When LBB is deemed necessary based on visual inspection and/or TcB reading, Bilistick will be used in parallel. The coprimary endpoints of the study are: (1) hyperbilirubinaemia necessitating treatment; (2) the number of heel pricks performed to quantify LBB. We aim to include 2310 neonates in a 2-year period. Using a decision tree model, a cost-effectiveness analysis will be performed.

ETHICS AND DISSEMINATION

This study has been approved by the Medical Research Ethical Committee of the Erasmus MC Rotterdam, Netherlands (MEC-2020-0618). Parents will provide written informed consent. The results of this study will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Dutch Trial Register (NL9545).

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.

The Impact of Phototherapy on the Accuracy of Transcutaneous Bilirubin Measurements in Neonates: Optimal Measurement Site and Timing

Transcutaneous bilirubinometer devices are widely applied to assess neonatal hyperbilirubinemia. However, the optimal skin site and timing of transcutaneous bilirubin (TCB) measurements for the strongest correlation with total serum bilirubin (TSB) levels after phototherapy are still unclear. We conducted a retrospective observational study evaluating the correlation of TCB and TSB levels in neonates postphototherapy. The TCB measurements on the forehead and mid-sternum at 0 and 30 min postphototherapy were assessed by using a JM-103 bilirubinometer. Paired TCB and TSB measurements were assessed by Pearson correlation and Bland–Altman plots. We analyzed 40 neonates with 96 TSB and 384 TCB measurements. The TSB level correlated moderately with the forehead TCB level at 30 min postphototherapy (r = 0.65) and less strongly with the midsternum TCB level at 0 min postphototherapy (r = 0.52). The forehead at 30 min after cessation of phototherapy was the best time point and location of TCB measurement for the assessment of neonatal jaundice status. The reliability of TCB measurements varied across skin sites and durations after phototherapy. The effectiveness of TCB measurement to assess neonatal hyperbilirubinemia is much better on covered skin areas (foreheads) 30 min postphototherapy. The appropriate application of transcutaneous bilirubinometers could aid in clinical practice and avoid unnecessary management.

Cephalocaudal progression of neonatal jaundice assessed by transcutaneous bilirubin measurements

OBJECTIVE

The cephalocaudal progression in neonatal jaundice is a well-known phenomenon. Since transcutaneous bilirubin measurements (TcB) are increasingly applied, for which different body site can be used, we aimed to quantify the cephalocaudal progression of neonatal jaundice through TcB and to assess the influence of gestational age, postnatal age and the degree of hyperbilirubinemia on this cephalocaudal progression.

STUDY DESIGN

In jaundiced neonates ≥32 weeks of gestational age, TcB was measured on 5 sites: forehead, sternum, hipbone, proximal tibia and foot, during the first two weeks of life.

RESULTS

58 neonates were included. Mean ratios of TcB on the 5 sites compared to the forehead were: sternum 1,03 (SD 0,14), hipbone 0,80 (SD 0,16), proximal tibia 0,63 (SD 0,14) and foot 0,44 (SD 0,15). Gestational age, postnatal age nor the degree of hyperbilirubinemia were associated with the cephalocaudal progression (ANOVA p > 0,05).

CONCLUSION

The cephalocaudal progression of neonatal jaundice is evident, with caudal levels of TcB being less than half of cephalic measurements. This implicates that TcB measurements caudal from the sternum are less reliable, and should be avoided. The degree of cephalocaudal progression is not associated with gestational or postnatal age, nor with height of bilirubin levels.

Measurement and clinical usefulness of bilirubin in liver disease

Elevated plasma bilirubin levels are a frequent clinical finding. It can be secondary to alterations in any stage of its metabolism: (a) excess bilirubin production (i.e., pathologic hemolysis); (b) impaired liver uptake, with elevation of indirect bilirubin; (c) impaired conjugation, prompted by a defect in the UDP-glucuronosyltransferase; and (d) bile clearance defect, with elevation of direct bilirubin secondary to defects in clearance proteins, or inability of the bile to reach the small bowel through bile ducts. A liver lesion of any cause reduces hepatocyte cell number and may impair the uptake of indirect bilirubin from plasma and diminish direct bilirubin transport and clearance through the bile ducts. Various analytical methods are currently available for measuring bilirubin and its metabolites in serum, urine and feces. Serum bilirubin is determined by (1) diazo transfer reaction, currently, the gold-standard; (2) high-performance liquid chromatography (HPLC); (3) oxidative, enzymatic, and chemical methods; (4) direct spectrophotometry; and (5) transcutaneous methods. Although bilirubin is a well-established marker of liver function, it does not always identify a lesion in this organ. Therefore, for accurate diagnosis, alterations in bilirubin concentrations should be assessed in relation to patient anamnesis, the degree of the alteration, and the pattern of concurrent biochemical alterations.

Bilirrubina: Medición y utilidad clínica en la enfermedad hepática

Un aumento en los niveles plasmáticos de bilirrubina es una alteración frecuente. Puede deberse a cualquier causa que altere alguna de las fases de su metabolismo: a) producción excesiva de bilirrubina (ej. hemólisis patológica); b) defecto en la captación hepática, con aumento de bilirrubina indirecta); c) defecto de conjugación, por alteración del enzima encargada (UDP-glucuronosiltransferasa); y d) defecto de excreción biliar, con aumento de bilirrubina directa, por defectos en las proteínas encargadas de la excreción, o bien por la imposibilidad del paso de la bilis a través de los conductos biliares hasta el intestino. Una lesión hepática de cualquier causa, al disminuir el número de hepatocitos, puede producir una disminución de la captación de bilirrubina indirecta desde el plasma y una disminución del transporte y excreción de la bilirrubina directa hacia los conductillos biliares. Se pueden usar diferentes técnicas analíticas para medir la bilirrubina y sus metabolitos en el suero, la orina y las heces. La bilirrubina sérica se mide mediante (1) la "reacción diazo", actualmente el método de referencia; (2) cromatografía líquida de alta resolución (HPLC); (3) métodos oxidativos, enzimáticos y químicos; (4) espectrofotometría directa; y (5) métodos transcutáneos. Aunque la bilirrubina es un marcador clásico de disfunción hepática, no siempre indica una lesión de este órgano. Por tanto, para obtener un diagnóstico preciso, el significado de las alteraciones de este parámetro biológico ha de valorarse en conjunción con la anamnesis del paciente, la magnitud de la alteración, y el patrón de las alteraciones bioquímicas. acompañantes.

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.

Screening methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments

Severe neonatal hyperbilirubinemia (SNH) is a serious condition that occurs worldwide. Timely recognition with bilirubin determination is key in the management of SNH. Visual assessment of jaundice is unreliable. Fortunately, transcutaneous bilirubin measurement for screening newborn infants is routinely available in many hospitals and outpatient settings. Despite a few limitations, the use of transcutaneous devices facilitates early recognition and appropriate management of neonatal jaundice. Unfortunately, however, advanced and often costly screening modalities are not accessible to everyone, while there is an urgent need for inexpensive yet accurate instruments to assess total serum bilirubin (TSB). In the near future, novel icterometers, and in particular optical bilirubin estimates obtained with a smartphone camera and processed with a smartphone application (app), seem promising methods for screening for SNH. If proven reliable, these methods may empower outpatient health workers as well as parents at home to detect jaundice using a simple portable device. Successful implementation of ubiquitous bilirubin screening may contribute substantially to the reduction of the worldwide burden of SNH. The benefits of non-invasive bilirubin screening notwithstanding, any bilirubin determination obtained through non-invasive screening must be confirmed by a diagnostic method before treatment. IMPACT: Key message: Screening methods for neonatal hyperbilirubinemia facilitate early recognition and timely treatment of severe neonatal hyperbilirubinemia (SNH). Any bilirubin screening result obtained must be confirmed by a diagnostic method. What does this article add to the existing literature? Data on optical bilirubin estimation are summarized. Niche research strategies for prevention of SNH are presented. Impact: Transcutaneous screening for neonatal hyperbilirubinemia contributes to the prevention of SNH. A smartphone application with optical bilirubin estimation seems a promising low-cost screening method, especially in low-resource settings or at home.

Comparing JM-105 and MBJ-20 Transcutaneous Bilirubinometers According to the Area Tested in Ethnically Diverse Late-Preterm and Term Neonates

This study aims to evaluate the correlation between the results of transcutaneous bilirubin (TcB) levels measured by the 2 transcutaneous bilirubinometers according to the area tested and to compare the TcB measurements and the serum bilirubin (SBR) levels. We screened 78 neonates born at more than 35 weeks of gestation and aged less than 168 hours for jaundice. We used JM-105 and MBJ-20 to measure the TcB at the forehead and the chest. For newborns who had high TcB measurements, we obtained blood samples during the subsequent 30 minutes. There was a strong correlation between the TcB measurements by JM-105 and MBJ-20 and this correlation was stronger when they were used on the sternum. The mean differences between the TcB measurements on the forehead and the sternum and the SBR levels were similar for the JM-105 and the MBJ-20. There was a strong correlation between SBR and the measurements using the 2 devices on the sternum (JM-105: r = 0.805; MBJ-20: r = 0.801), unlike measurements taken on the forehead by each device (r = 0.777 and r = 0.751, respectively). Both devices had high sensitivity and negative predictive values at SBR level of less than 230 μmol/L (<13.4 mg/dL) and high specificity and positive predictive values at SBR level of 230 μmol/L and greater (>13.4mg/dL). Both devices equally overestimated the actual SBR and had more reliable results if used on the sternum.

Transcutaneous Bilirubin Monitoring in Preterm Infants of 23 to 34 Weeks' Gestation

OBJECTIVE

 The study aimed to evaluate the validity of transcutaneous bilirubin (TcB) measurements at three sites in premature infants born at 23^0/7 to 34^6/7 weeks' gestational age (GA) compared with total serum bilirubin (TSB) measurements.

STUDY DESIGN

 A prospective study was conducted at Banner - University Medical Center Phoenix, where informed consent was obtained from the infant's parent or legally authorized representative. Cohort A was comprised of infants 23^0/7 to 28^6/7 weeks' GA and Cohort B contained subjects 29^0/7 to 34^6/7 weeks' GA. Baseline TSB measurements were collected at approximately 24 hours of life, as the standard of care and the TcB measurements were obtained from the sternum, interscapular, and buttock areas at approximately ± 30 minutes from collection of the TSB. Statistical analysis of measurements including sensitivity, specificity, positive, and negative predictive values, and the area under the receiver operator characteristic curve (AUROC) were performed.

RESULTS

 A total of 166 infants were included in the study population. Cohort A consisted of 41 subjects and Cohort B contained 125 subjects. The results showed that baseline TcB measurements from the interscapular area were the most sensitive and specific with TSB levels >5.0 mg/dL in Cohort A. Baseline TcB measurements from the sternum demonstrated greatest sensitivity and specificity when the TSB level was >8.0 mg/dL in Cohort B. In general, each of the three sites in both cohorts demonstrated excellent AUROCs and negative predictive values.

CONCLUSION

 The use of a TcB meter in preterm infants can be a reliable noninvasive screening tool for hyperbilirubinemia, and it may be beneficial in decreasing painful stimuli and iatrogenic blood loss when used as an adjunct to TSB monitoring.

KEY POINTS

· Interscapular TcB is sensitive/specific in 23 to 29 weeks' GA.. · Sternal TcB is sensitive/specific in 29 to 35 weeks' GA.. · TcB readings are reliable in preterm infants.. · TcB is reliable when serum bilirubin is >5.0 mg/dL..

Inter-device reproducibility of transcutaneous bilirubin meters

BACKGROUND

Transcutaneous bilirubinometry is a widely used screening method for neonatal hyperbilirubinemia. Deviation of the transcutaneous bilirubin concentration (TcB) from the total serum bilirubin concentration (TSB) is often ascribed to biological variation between patients, but variations between TcB meters may also have a role. This study aims to provide a systematic evaluation of the inter-device reproducibility of TcB meters.

MATERIALS AND METHODS

Thirteen commercially available TcB meters (JM-105 and JM-103) were evaluated in vitro on phantoms that optically mimic neonatal skin. The mimicked TcB was varied within the clinical range (0.5-181.3 μmol/L).

RESULTS

Absolute differences between TcB meter outcomes increased with the measured TcB, from a difference of 5.0 μmol/L (TcB = 0.5 μmol/L phantom) up to 65.0 μmol/L (TcB = 181.3 μmol/L phantom).

CONCLUSION

The inter-device reproducibility of the examined TcB meters is substantial and exceeds the specified accuracy of the device (±25.5 μmol/L), as well as the clinically used TcB safety margins (>50 µmol/L below phototherapy threshold). Healthcare providers should be well aware of this additional uncertainty in the TcB determination, especially when multiple TcB meters are employed in the same clinic. We strongly advise using a single TcB meter per patient to evaluate the TcB over time.

IMPACT

Key message: The inter-device reproducibility of TcB meters is substantial and exceeds the clinically used TcB safety margins. What this study adds to existing literature: The inter-device reproducibility of transcutaneous bilirubin (TcB) meters has not been reported in the existing literature. This in vitro study systematically evaluates this inter-device reproducibility.

IMPACT

This study aids in a better interpretation of the measured TcB value from a patient and is of particular importance during patient monitoring when using multiple TcB meters within the same clinical department. We strongly advise using a single TcB meter per patient to evaluate the TcB over time.

Reliability of transcutaneous bilirubin determination based on skin color determined by a neonatal skin color scale of our own

Measurement of transcutaneous bilirubin (TcB) is widely used to estimate serum bilirubin (SB). However, its reliability depending on skin tone is still controversial. Ethnic classification does not correlate well with skin tone. We aimed to determine the reliability of transcutaneous bilirubin in a multiethnic population based on skin color according to our neonatal skin color scale. We conducted a prospective, observational study comparing SB and TcB among different skin colors. With the blood sample routinely obtained at 48-72 h for the screening of inborn errors of metabolism, we determined SB and TcB with a jaundice meter. We obtained data from 1359 newborns (color 1 337, color 2 750, color 3 249, color 4 23) and analyzed 1549 dyads SB/TcB. Correlation between TcB and serum bilirubin was very good (R² = 0.908-0.956), globally and by color group, with slight differences between darker and lighter skin colors. Bland-Altman plots showed different mean bias depending on skin color. Conclusions: Our study not only supports the reliability of TcB to assess SB regardless of skin color, but also supports the fact that TcB tends to overestimate SB in a higher degree in dark-skinned neonates. This may help reduce the number of blood samples for newborns. What is Known: • Jaundice meters are extensively used to diagnose neonatal hyperbilirubinemia, although controversies exist on their reliability depending on skin color. • 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 a multiethnic population depending on skin color after classifying our neonates into color groups with our own validated neonatal skin color scale.

Noninvasive methods for bilirubin measurements in newborns: A report

New technologies have become available for noninvasive assessments of neonatal hyperbilirubinemia. Our objective is to review the noninvasive methods for measuring bilirubin in the newborn. We searched relevant literature from 1966 to January 1, 2020, which included cross-sectional studies to define the accuracy of any noninvasive methods for measuring or estimating total serum/plasma bilirubin (TB) levels in newborns. We identified and included 83 relevant studies of direct visual assessment, icterometry, mobile phone applications, and transcutaneous bilirubinometry (TcB). Compared with laboratory TB measurements, visual assessment was the least accurate and least reliable (r: 0.37 to 074), while TcB was the most accurate, but not always near-equivalent (r: 0.45 to 0.99). The sensitivity and specificity of TcB cut-off values to detect significant hyperbilirubinemia (TB>95th percentile for age in hours) ranged from 74% to 100% and 18% to 89%, respectively.

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.

Diagnostic Properties of a Portable Point-of-Care Method to Measure Bilirubin and a Transcutaneous Bilirubinometer

BACKGROUND

Recently, the Bilistick®, a point-of-care instrument to measure bilirubin levels, has been developed. It is fast and cheaper than transcutaneous bilirubin (TCB)-measuring devices, but data on diagnostic properties are scarce.

OBJECTIVE

This study aimed to compare the performance of the Bilistick® (BM-BS 1.0 - FW version 2.0.1) and the JM-105 bilirubinometer for measuring bilirubin.

METHOD

This is a prospective study in infants born after ≥32 weeks' gestation, and/or a birth weight of ≥1,500 g, and a postnatal age ≤14 days in Surabaya, Indonesia. Bilirubin was measured with the Bilistick® System (BM-BS 1.0 - FW version 2.0.1), transcutaneously (TCB) with the JM-105 bilirubinometer, and in serum (TSB) with a routine laboratory technique. Mean differences and 95% limits of agreement (LOA) and correlations were calculated.

RESULT

We enrolled 149 neonates and 126 had paired measurements of Bilistick® bilirubin, TCB, and TSB. Bilistick® failed in 16 (10.7%) infants. Mean Bilistick® bilirubin-TSB difference was -11 µmol/L (95% LOA: -101 to 79 µmol/L) and r = 0.738 (p < 0.001). Mean TCB-TSB difference was 26 μmol/L (95% LOA: -33 to 88) and r = 0.785 (p < 0.001). The sensitivity, specificity, PPV, and NPV for Bilistick® bilirubin for a TSB above treatment thresholds were 0.74, 0.84, 0.67, and 0.88, respectively, and for TCB 0.92, 0.64, 0.54, and 0.95, respectively.

CONCLUSION

The Bilistick® System (BM-BS 1.0 - FW version 2.0.1) underestimates TSB, whereas TCB overestimates TSB in jaundiced Indonesian infants. Further improvement of Bilistick®'s diagnostic accuracy with less false-negative readings is essential to increase its use.

The forehead is a better site than the sternum to check transcutaneous bilirubin during phototherapy in sick infants

Background

To confirm the accuracy of transcutaneous bilirubin (TcB) in the neonatal intensive care unit both with and without phototherapy, and compare forehead and sternum as the TcB assessment site.

Methods

We simultaneously assessed the total serum bilirubin (TSB) and TcB at the forehead and sternum, using a JM-103 bilirubinometer. We analyzed the correlation between the TSB and TcB assessed at the forehead and sternum, with measurements classified as ‘without phototherapy’ (before phototherapy and > 24 hours after phototherapy discontinuation) and ‘with phototherapy’ (after 24 hours of phototherapy).

Results

There were 1,084 paired forehead and sternum TcB measurements, with the corresponding TSB measurement, from 384 infants. Their mean gestational age of 35.4 ± 3.2 weeks (62% were preterm) and a mean birth weight of 2434 ± 768 grams, and TSB was 6.61 ± 3.56 mg/dL. Without phototherapy, TcB values at the forehead and sternum were correlated well to the TSB value (r = 0.925 and 0.915, respectively). With phototherapy, TcB values at the forehead and sternum were significantly correlated with the TSB value, but TcB at the forehead (r = 0.751) was a better match to the TSB than was TcB at the sternum (r = 0.668). Additionally, Bland-Altman plots showed a greater degree of underestimation of the TSB by TcB at the sternum with phototherapy.

Conclusions

TcB was more accurate in infants not receiving phototherapy. During phototherapy, it is better to assess TcB at the forehead rather than at the sternum.

Ratio of cord blood bilirubin and albumin as predictors of neonatal hyperbilirubinaemia

AIM OF THE STUDY

To compare cord blood albumin (CBA) and cord blood bilirubin (CBB) at birth as predictors for development of neonatal hyperbilirubinaemia.

MATERIAL AND METHODS

CBA and CBB of 388 healthy term neonates born by lower segment caesarean section (LSCS) were determined at birth and transcutaneous bilirubin (TCB) was measured every 12 hours from birth until 7 days of life or development of hyperbilirubinaemia requiring phototherapy.

RESULTS

The cut-off value of CBB and CBA as obtained by the receiver operating characteristic (ROC) curve was 1.90 mg/dl and 3.17 g/dl respectively. The sensitivity, specificity and positive predictive value (PPV) for CBB were 97.4%, 40.6% and 71.09% while for CBA they were 40.8%, 34.8% and 48.41%. The cut-off value for CBB/CBA ratio was 0.719 as obtained by the ROC curve and was determined to have 97.4% sensitivity, 62.6% specificity and a PPV of 79.61%.

CONCLUSIONS

CBB/CBA is a better indicator compared to CBA and CBB alone for prediction of neonatal hyperbilirubinaemia.

Accuracy of Transcutaneous Bilirubin Versus Serum Bilirubin Measurement in Preterm Infants Receiving Phototherapy: A Systematic Review

BACKGROUND

Jaundice is a common condition among preterm infants in the neonatal intensive care unit (NICU). Total serum bilirubin (TSB) offers a gold standard tool for measurement, but blood sampling can be costly, time-consuming, and not without risks of infection and pain. Transcutaneous bilimeter (TcB) allows for noninvasive assessment of bilirubin. However, due to questions of accuracy the use of the TcB in preterm infants receiving phototherapy has not been widely adapted in the NICU.

PURPOSE

To systematically review studies that measure TcB versus TSB bilirubin in preterm infants who are receiving phototherapy.

METHODS

A systematic electronic search of databases (CINAHL, EMBASE, Cochrane, Medline, PubMed) was completed for English language publications. No date limitation was placed on the search. Inclusion criteria were based on preterm infants that were in the NICU receiving or had recently received phototherapy.

RESULTS

Nine studies of different quantitative study designs were reviewed. A good to strong correlation between TcB and TSB in preterm infants receiving phototherapy was demonstrated. There was a stronger correlation found in studies that examined TcB in unexposed skin areas during phototherapy.

IMPLICATIONS FOR PRACTICE

TcB may allow for a reduction in blood sampling, which would reduce painful procedures, reduce the risk of infection and anemia resulting from repeated blood sampling. It also acts as a more time and cost-efficient measurement tool.

IMPLICATIONS FOR RESEARCH

Larger scaled quantitative studies on the accuracy of TcB in preterm infants receiving phototherapy are needed to provide more evidence-based data and guide clinical practice on this topic.

Neonatal Indirect Hyperbilirubinemia

Neonatal indirect hyperbilirubinemia (IHB) is caused by an imbalance in bilirubin production and elimination. Approximately 60% of term and 80% of preterm infants develop jaundice in the first week of age. This review seeks to provide the reader with a thorough understanding of the physiology of bilirubin, etiology of IHB, and management of severe IHB. Phototherapy and exchange transfusion remain the mainstays of treatment for severe IHB. Noninvasive screening tools, innovative treatments, and a better understanding of how prematurity and genetics contribute to severe IHB have improved our understanding of IHB and may help eliminate the hazards associated with severe IHB, including kernicterus spectrum disorder.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Predictability of transcutaneous bilirubinometry in late preterm and term infants at risk for pathological hyperbilirubinemia

BACKGROUND

The aim was to assess the predictability of transcutaneous bilirubinometry in late preterm and term neonates at risk for pathological hyperbilirubinemia, and to identify the neonatal population in which transcutaneous bilirubin most accurately predicts serum bilirubin level (SB, mg/dl).

METHODS

The correlations between transcutaneous bilirubin (TCB, mg/dl) and SB in different neonatal population subsets; and between ΔTSB (TCB-SB) and relevant neonatal variables and clinical groups were analyzed.

RESULTS

TCB correlated with SB (r = 0.82, p < 0.05) in the cohort (n = 350) and in population subsets (r = 0.81-0.9, p < 0.001). Black infants with gestational age (GA) >35 weeks and chronological age (CA) >3 days recorded strongest correlation (r = 0.9, p < 0.001) followed by Blacks, and non-Black infants with CA >3 days and GA >35 weeks. ΔTSB was positive in Blacks, and in infants with CA <3 days, or with no phototherapy. ΔTSB was negative in non-Blacks, in infants with positive direct Coombs test (DC+) or those receiving phototherapy. Black race [beta (SE) = 1.3(0.33), p < 0.001] had positive, while CA [beta (SE) =-1.74 (0.36), p < 0.001], DC + status [beta (SE) =-0.72 (0.25), p = 0.004] and receipt of phototherapy [beta (SE) =-0.84 (0.21), p < 0.001] each had negative correlation with ΔTSB. ΔTSB for Blacks was >Whites, Hispanics and Asians.

CONCLUSION

SB is best predicted by TCB in Black infants with CA over 3 days and GA over 35 weeks. Variability in SB estimation by TCB is race, CA and immune mediated hemolysis specific.

Transcutaneous bilirubin level to predict hyperbilirubinemia in preterm neonates

Background: Hyperbilirubinemia is common in neonates, with higher prevalence among preterm neonates, which can lead to severe hyperbilirubinemia. Assessment of total serum bilirubin (TSB) and the use of a transcutaneous bilirubinometry (TcB) are existing methods that identify and predict hyperbilirubinemia. This study aimed to determine TcB cut-off values during the first day for preterm neonates to predict hyperbilirubinemia at 48 and 72 hours.

Methods: This cohort study was conducted at Dr. Soetomo General Hospital from September 2018 to January 2019 a total of 90 neonates born ≤35 weeks. They were divided into two groups (Group I: 1000-1500 grams; Group II: 1501-2000 grams). The bilirubin levels were measured on the sternum using TcB at the ages of 12, 24, and 72 hours. TSB measurements were taken on the third day or if the TcB level reached phototherapy threshold ± 1.24 mg/dL and if TcB showed abnormal results (Group I: 5.76-8.24 mg/dL; Group II: 8.76-11.24 mg/dL). Hyperbilirubinemia was defined as TSB ≥7 mg/dL for Group I and >10 mg/dL for Group II.

Results: In total, 38 Group I neonates and 48 Group II neonates were observed. Almost half of the neonates in Group I (45%) suffered from hyperbilirubinemia at the age of 48 hours, along with 46% of Group II at 72 hours. The best 24-hour-old TcB cut-off values to predict hyperbilirubinemia at 48 hours were calculated to be 4.5 mg/dL for Group I and 5.8 mg/dL for Group II. The determined 24-hour-old TcB value to predict hyperbilirubinemia at 72 hours was 5.15 mg/dL for Group II.

Conclusion: TcB values in the early days of life can be used as hyperbilirubinemia predictors on the following days for preterm neonates. Close monitoring should be managed for those with TcB values higher than the calculated cut-off values.

Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC.Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable.Methods: A single-centre prospective study (February to May 2017) in Cap Haïtien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods.Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 µmol/L, 95% CI -10.2-32.5 µmol/L). However, at higher bilirubin levels (>250 µmol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased.Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 µmol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.Abbreviations: LIC: low income countries; LMIC: low and middle income countries; TcB: transcutaneous bilirubinometry; TSB: transcutaneous serum biliubin.

Evaluation of the Kejian KJ-8000 bilirubinometer in an Australian setting

AIM

To evaluate the accuracy of the Kejian 8000 (KJ-8000) transcutaneous bilirubinometer in infants of differing ethnicity and gestational age.

METHODS

This was a prospective study of infants in the Newborn Care Unit at Gold Coast University Hospital. Transcutaneous bilirubin (TcB) and serum bilirubin (SBR) results were compared using linear regression and a Bland-Altman plot. Predicted indices were calculated to assess the KJ-8000 as a screening tool using local jaundice management guidelines.

RESULTS

A total of 416 paired samples were collected from 201 infants. There was a strong correlation between TcB and SBR with a Pearson correlation coefficient of 0.8 (<0.00001). The bias was -5.9 μmol/L (95% confidence interval: -101, 89). The bias was not evenly spread, with the KJ-8000 tending to underestimate at higher SBR levels. Infants <32 weeks' gestation had a poor correlation of 0.48. Non-Caucasian infants were more likely to have TcB overestimation, and measurements were less precise. As a screening tool using local guidelines, the KJ-8000 had a sensitivity, specificity, positive predictive value and negative predictive value of 83, 53, 20 and 96%, respectively, and is predicted to avoid blood tests in 48% of infants screened.

CONCLUSIONS

In this study, the correlation and agreement of TcB measurements using the KJ-8000 were not as good as has been reported with other more studied devices but may still have value as a screening tool. The poor correlation in preterm infants suggests that use should be restricted to term infants. The overall results of this study are affected by an underrepresentation of term infants, and so, further clinical assessment of this device should be undertaken before it can be recommended for widespread use.

The accuracy of transcutaneous bilirubinometry in preterm infants

OBJECTIVE

To evaluate the correlation between total serum and transcutaneous bilirubin and to determine the reliability of transcutaneous bilirubinometry for screening and monitoring of neonatal jaundice among preterms.

STUDY DESIGN

Ninety nine infants with gestational ages ≤34 weeks were prospectively enrolled. Babies were classified into three groups as; 24-28, 29-31, and 32-34 weeks. Total serum bilirubin and simultaneous transcutaneous bilirubin were measured before the onset of phototheraphy, during and at 24 h after discontinuing phototherapy.

RESULTS

Total serum bilirubin significantly correlated with transcutaneous bilirubin in the whole cohort (r = 0.867, p < 0.001) and in each group before, during and after phototheraphy. Hypotension was the only variable which effects the difference between two methods at postnatal first day of life (p = 0.039).

CONCLUSION

Transcutaneous bilirubin levels were highly correlated with total serum bilirubin levels even in 24-28 GW babies. Transcutaneous bilirubin may be useful for screening and monitoring of jaundice in very preterm newborns.

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.

Transcutaneous bilirubinometry during and after phototherapy in preterm infants: a prospective observational study

OBJECTIVE

To examine the accuracy of transcutaneous bilirubinometry (TCB) measurements during and after phototherapy (PT) in preterm infants.

DESIGN

Prospective observational cohort study.

SETTING

Level III neonatal centre.

PATIENTS

Preterm infants (from 23+0 to 36+6 weeks of gestation) born between June 2017 and May 2018 requiring PT.

INTERVENTIONS

TCB was measured from an exposed area of the skin (the sternum; TCBU) and the covered area of the skin under the nappy (the bony part of the upper outer quadrant of the buttock; TCBC) within an hour of obtaining total serum bilirubin (TSB).

MAIN OUTCOME MEASURES

Correlation and agreement between TCB (TCBU and TCBC) and TSB during and after PT.

RESULTS

We have enrolled 196 preterm infants. There was a significant correlation between TSB and TCB during PT (r=0.72, 95% CI 0.66 to 0.77 in covered area; r=0.75, 95% CI 0.70 to 0.80 in uncovered area) and after PT (r=0.87, 95% CI 0.83 to 0.91). TCB underestimated TSB level during PT, with a mean TCBC-TSB difference of -25±43 (95% agreement limits of 62 to -112) and a mean TCBU-TSB difference of -48±46 (95% agreement limits of 45 to -140). The agreement between TCB and TSB after cessation of PT improved, with TCB underestimating TSB by a mean TCB-TSB difference of -10±31 (95% agreement limits of 52 to -72).

CONCLUSION

TCB measurements correlated strongly with TSB levels during and after PT. However, there was a wide and clinically relevant disagreement between TCB and TSB measurements during the PT phase, improving significantly after PT.

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.

Screening and treatment to reduce severe hyperbilirubinaemia in infants in primary care (STARSHIP): a factorial stepped-wedge cluster randomised controlled trial protocol

INTRODUCTION

Jaundice caused by hyperbilirubinaemia is a physiological phenomenon in the neonatal period. However, severe hyperbilirubinaemia, when left untreated, may cause kernicterus, a severe condition resulting in lifelong neurological disabilities. Although commonly applied, visual inspection is ineffective in identifying severe hyperbilirubinaemia. We aim to investigate whether among babies cared for in primary care: (1) transcutaneous bilirubin (TcB) screening can help reduce severe hyperbilirubinaemia and (2) primary care-based (versus hospital-based) phototherapy can help reduce hospital admissions.

METHODS AND ANALYSIS

A factorial stepped-wedge cluster randomised controlled trial will be conducted in seven Dutch primary care birth centres (PCBC). Neonates born after 35 weeks of gestation and cared for at a participating PCBC for at least 2 days within the first week of life are eligible, provided they have not received phototherapy before. According to the stepped-wedge design, following a phase of 'usual care' (visual assessment and selective total serum bilirubin (TSB) quantification), either daily TcB measurement or, if indicated, phototherapy in the PCBC will be implemented (phase II). In phase III, both interventions will be evaluated in each PCBC. We aim to include 5500 neonates over 3 years.Primary outcomes are assessed at 14 days of life: (1) the proportion of neonates having experienced severe hyperbilirubinaemia (for the TcB screening intervention), defined as a TSB above the mean of the phototherapy and the exchange transfusion threshold and (2) the proportion of neonates having required hospital admission for hyperbilirubinaemia treatment (for the phototherapy intervention in primary care).

ETHICS AND DISSEMINATION

This study has been approved by the Medical Research Ethics Committee of the Erasmus MC Rotterdam, the Netherlands (MEC-2017-473). Written parental informed consent will be obtained. Results from this study will be published in peer-reviewed journals and presented at (inter)national meetings.

TRIAL REGISTRATION NUMBER

NTR7187.

Transcutaneous bilirubin nomogram for evaluating the risk of hyperbilirubinemia in Iranian healthy newborns

BACKGROUND

Hyperbilirubinemia, which is mostly benign, is one of the most common problems in neonates. This study was conducted to draw a skin bilirubin nomogram for evaluating the risk of hyperbilirubinemia requiring treatment.

METHODS

This cross-sectional study recruited 1066 healthy infants. The first transcutaneous bilirubin (TcB) measurement was performed before hospital discharge and within 12-48 h of birth. The neonates were followed up for 6 days after discharge based on their age at the time of discharge. The neonates were divided into four groups based on the TcB values before discharge and age in hours, including the low-risk, medium-low-risk, medium-high-risk and high-risk groups. The percentage of neonates who progressed toward severe hyperbilirubinemia was then calculated in each percentile based on the follow-up TcB measurement. Stata software was used to draw the nomogram. Based on the TcB values at discharge and the neonate's age in hours, the skin bilirubin nomogram was drawn in 40, 75 and 95 percentiles.

RESULTS

A total of 4.9% of the neonates were in the high-risk group, 18.9% in the medium-high-risk group, 34.8% in the medium-low-risk group and 41.2% in the low-risk group. The risk of severe jaundice in the follow-up of the neonates in the highest-risk to the lowest-risk groups was 48.9, 14.5, 9.7 and 3.3%, respectively.

CONCLUSION

The skin bilirubin nomogram can be used to predict severe hyperbilirubinemia in Iranian infants.

Reproducibility of BiliCare™ Transcutaneus Bilirrubin Meter in Mexican Newborns

Background

Newborn hyperbilirubinemia is considered a worldwide health problem that demands medical evaluation. Noninvasive transcutaneous bilirubin (TcB) has been used as a screening method with different devices but there has not been any evaluation of reproducibility of the same brand devices. The BiliCare™ system is evaluated to demonstrate consistency between measurements with four different devices.

Methods

336 TcB measurements were obtained with four BiliCare™ devices in 21 Mexican icteric newborns with a mean postnatal age of 44.1 hours of life and 38 weeks of gestation (33–41). Two measurements were taken in the same ear alternatively at the scaphoid fossa with each device. TcB values were compared between devices. Validity was compared with total serum bilirubin (TB).

Results

intraclass correlation coefficient demonstrates a minimum limit in the study of 0.945 and maximum of 0.988 with the same device. Correlations with serum and between devices gave results above 0.932.

Conclusions

BiliCare™ transcutaneous bilirubin measurement instrument has very good intra- and interdevice reproducibility; also correlation of TcS with serum bilirubin gave statistically the same results.

How skin anatomy influences transcutaneous bilirubin determinations: an in vitro evaluation

BACKGROUND

Transcutaneous bilirubinometry is an effective screening method for neonatal hyperbilirubinemia. Current transcutaneous bilirubin (TcB) meters are designed for the "standard" situation of TcB determinations on the forehead or sternum of term newborns. We hypothesize that skin anatomy can considerably influence TcB determinations in non-standard situations-e.g., on preterm newborns or alternative body locations.

METHODS

A commercially available TcB meter (JM-105) was evaluated in vitro on phantoms that accurately mimic neonatal skin. We varied the mimicked cutaneous hemoglobin content (0-2.5 g/L), bone depth (0.26-5.26 mm), and skin maturity-related light scattering (1.36-2.27 mm^-1) within the clinical range and investigated their influence on the TcB determination. To obtain a reference frame for bone depth at the forehead, magnetic resonance head scans of 46 newborns were evaluated.

RESULTS

The TcB meter adequately corrected for mimicked hemoglobin content. However, TcB determinations were influenced considerably by clinically realistic variations in mimicked bone depth and light scattering (deviations up to 72 µmol/L). This greatly exceeds the specified accuracy of the device (±25.5 µmol/L).

CONCLUSION

As bone depth and light scattering vary with gestational maturity and body location, caretakers should be cautious when interpreting TcB measurements on premature newborns and non-standard body locations.

Laboratory validation and field usability assessment of a point-of-care test for serum bilirubin levels in neonates in a tropical setting

Background: Screening and monitoring serum bilirubin (SBR) in neonates is crucial to prevent neonatal hyperbilirubinemia (NH)-associated morbidity and mortality worldwide. A lack of resources is often a barrier for measuring SBR in developing countries. Reliable, cost-effective, easy to use point-of-care (POC) SBR tests are needed. This study aimed to evaluate the technical accuracy and usability of the Bilistick System (BS), a new bilirubin POC test, in a tropical setting. Methods: This was a mixed-methods study, including laboratory validation of the BS, direct observation of technical procedures as performed by the midwives and midwives' assessment of the device's easiness of use through focus group discussions (FGD) and a self-administered questionnaire. The study was conducted in a field clinic of the Shoklo Malaria Research Unit along the Thailand-Myanmar border between January and December 2017. Results: A total of 173 samples were tested at a median age of 4 days. BS generated an error message-providing no SBR readout-in 48.6% of the tests performed. For the tests that yielded a result, the correlation coefficient (95% CI) between BS and routine laboratory bilirubinometer SBR was 0.87 (0.77-0.93). The accuracy decreased with increasing haematocrit and at higher humidity (≥75%). Direct observation of the operators using the device and analysis of the focus group discussions and questionnaires indicated that the BS was considered easy to use and required limited training. Conclusions: This evaluation showed that the BS, in its current formulation, does not provide reliable results for measuring SBR in a tropical, low-resource setting  but has acceptable usability features.