Prediction of severe hyperbilirubinaemia using the Bilicheck transcutaneous bilirubinometer

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.

An investigation of motor development and sensory processing skills in infants with a history of hyperbilirubinemia

BACKGROUND

Hyperbilirubinemia is a clinical picture frequently occurring in the neonatal period and may negatively affect the development of infants.

AIMS

To evaluate term infants with hyperbilirubinemia in terms of both motor development and sensory processing skills and to compare them with their healthy peers without hyperbilirubinemia.

STUDY DESIGN

A cross-sectional study.

SUBJECTS

Children born at term, aged 10-18 months, with and without a history of hyperbilirubinemia were included in the study.

OUTCOME MEASURES

After demographic information was recorded, motor development was evaluated with the Peabody Motor Development Scale-2 and sensory processing skills were evaluated with the Test of Sensory Function in Infant.

RESULTS

A total of 42 children (mean ± SD age of the children 13.07 ± 1.47 months, 22 with hyperbilirubinemia and 20 without hyperbilirubinemia) were included in the study. A statistically significant difference was found in the gross motor (p = 0.02), fine motor (p = 0.03), and total motor (p = 0.017) development scores of the Peabody Motor Development Scale-2 and in the adaptive motor functions (p = 0.004), visual tactile integration (p < 0.001), and total scores (p = 0.004) of The Test of Sensory Function in Infant in favor of the control group.

CONCLUSIONS

The motor and sensory processing skills of children born at term with hyperbilirubinemia may be negatively affected. Infants with hyperbilirubinemia should be evaluated from the early period not only in terms of motor but also sensory processing skills and should be supported with appropriate intervention programs.

Bilirubin Measurement Through a Smartphone Application in Preterm Infants

BACKROUND

Aim of the present study is to evaluate the feasibility and reliability of an smartphone application for monitore of bilirubin levels in preterm infants.

METHODS

Preterm infants hospitalized in the neonatal intensive care unit with gestational age of<35 weeks were included. Exclusion criteria were parental reluctance and requirement of phototherapy in the last 12 hours. Measurements were obtained through a smartphone application (BiliScan) along with simultaneous transcutaneous device (Dräger JM 105) and venous blood biochemistry.

RESULTS

Mean gestational age was 30.8±2.4 weeks and birth weight was 1622±566 g. Measurements were obtained at a median of 4 (1-21) days of life. Twenty-five infants (19.4%) had ABO and/or Rh incompatibility and 39 infants (30.2%) required phototherapy. None of the cases required exchange transfusion. Mean total serum bilirubin (TSB) level was 8.16±2.60 mg/dL, mean transcutaneous bilirubin (TcB) level was 8.60±2.70 mg/dL, and the mean bilirubin level measured by BiliScan was 7.26±2.68 mg/dL. For TSB and TcB measurements, the intraclass correlation coefficient (ICC) was found to be 0.915 (95% confidence interval 0.835-0.951; p<0.001) and a strong positive correlation was found between these two measurements. When TSB and BiliScan measurements were compared, ICC was found to be significant as 0.512 (95% confidence interval 0.353-0.638; p<0.001), with a moderate correlation.

CONCLUSIONS

In this study, we evaluated the feasibility and reliability of a smartphone application for monitoring bilirubin levels in preterm infants. Although BiliScan measurements reported to display high correlation in term infants, a moderate correlation was found in the preterm infants. It is an emerging low-cost, non-invasive alternative for neonatal jaundice monitoring, however, results should be interpreted with caution in preterm infants.

Glucose-6-phosphate dehydrogenase deficiency among neonates with jaundice in Africa; systematic review and meta-analysis

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic disorder caused by a structural abnormality in the enzyme. G6PD deficiency is most prevalent among African, Asian, and Mediterranean people. This study aimed to investigate how prevalent G6PD deficiency is in African neonates with jaundice.

Methods

The public sources, such as PubMed, Science Direct, Google Scholar, and Africa Journal Online were searched for articles that reported the prevalence of G6PD deficiency published before March 21st, 2022. The Joanna Briggs Institute's (JBI) critical assessment checklist was used to evaluate the quality of individual studies. STATA-17 was used to do the statistical analysis. The pooled prevalence of G6PD deficiency in neonates with jaundice in Africa was calculated using a forest plot and a random effects model. I2 statistics and Galbraith plots were used to assess heterogeneity. Publication bias was assessed using a funnel plot and Egger's statistical test.

Results

Ten studies involving 1555 neonates with jaundice were involved in the study. G6PD deficiency was prevalent in 24.60% of African neonates with jaundice (95% CI:12.47-36.74) with considerable heterogeneity (I2 = 100%). Nigerian neonates with jaundice had the highest G6PD deficiency (49.67%), whereas South Africans had the lowest (3.14%).

Conclusion

G6PD deficiency has been implicated in a significant portion of African neonates with jaundice, notwithstanding the need for greater research on predisposing variables from other countries. Therefore, it should be thought of performing screening and diagnostic laboratory tests for G6PD deficiency.

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.

Neonatal Jaundice Diagnosis Using a Smartphone Camera Based on Eye, Skin, and Fused Features with Transfer Learning

Neonatal jaundice is a common condition worldwide. Failure of timely diagnosis and treatment can lead to death or brain injury. Current diagnostic approaches include a painful and time-consuming invasive blood test and non-invasive tests using costly transcutaneous bilirubinometers. Since periodic monitoring is crucial, multiple efforts have been made to develop non-invasive diagnostic tools using a smartphone camera. However, existing works rely either on skin or eye images using statistical or traditional machine learning methods. In this paper, we adopt a deep transfer learning approach based on eye, skin, and fused images. We also trained well-known traditional machine learning models, including multi-layer perceptron (MLP), support vector machine (SVM), decision tree (DT), and random forest (RF), and compared their performance with that of the transfer learning model. We collected our dataset using a smartphone camera. Moreover, unlike most of the existing contributions, we report accuracy, precision, recall, f-score, and area under the curve (AUC) for all the experiments and analyzed their significance statistically. Our results indicate that the transfer learning model performed the best with skin images, while traditional models achieved the best performance with eyes and fused features. Further, we found that the transfer learning model with skin features performed comparably to the MLP model with eye features.

Effect of head covering on phototherapy induced hypocalcemia in term neonates with hyperbilirubinemia: A randomised controlled study

BACKGROUND

Phototherapy is the primary treatment for hyperbilirubinemia in neonates. Hypocalcemia is a lesser known but potential detrimental effect of phototherapy. It has been hypothesized that phototherapy inhibits pineal secretion of melatonin, which blocks the effect of cortisol on bone calcium. Therefore, unchecked cortisol increases bone uptake of calcium and induces hypocalcemia. Covering head during phototherapy in order to prevent light reaching to the pineal gland which eventually leads to the prevention of hypocalcemia is hypothesized to prevent hypocalcemia but it lacks sufficient evidence worldwide.

METHOD

It is a prospective, randomized controlled study. 112 neonates were randomized into two groups of 56 neonates. Group A underwent phototherapy without head cover and group B with head covered by a cap.

RESULT

The mean decline in serum ionic calcium after 48 hours of phototherapy in group A and group B was 0.57±0.37 mg/dl and 0.34±0.24 mg/dl respectively. This decline in serum ionic calcium was significantly higher in group A. (p < 0.001). 26.8% newborns from group A developed hypocalcemia while in group B only 14.3% developed hypocalcemia however it was not found to be statistically significant. Incidence of symptomatic hypocalcemia between the two groups was also not significant.

CONCLUSION

There was significant reduction in serum calcium in neonates undergoing phototherapy without head cover as compared to neonates with head cover but risk of hypocalcemia was not significant. Further studies with larger sample size including preterm are recommended.

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.

Neurodevelopmental outcome of healthy term newborn with serum bilirubin >15 mg/dl at one year

BACKGROUND

Neonatal hyperbilirubinemia is a common medical emergency in early neonatal period. Unconjugated bilirubin is neurotoxic and can lead to lifelong neurological sequelae in survivors.

OBJECTIVE

To find out the association between serum bilirubin and neurodevelopmental outcome at 1 year of age using Development Assessment Scale for Indian Infants (DASII).

METHODS

A prospective cohort study was conducted in the Department of Pediatrics of a tertiary care institution of Central India between January 2018 and August 2019. Total 108 term healthy neonates, with at least one serum bilirubin value of >15 mg/dl, were included. Subjects were divided into three groups based on the serum bilirubin; group 1: (15-20 mg/dl) -85(78.7%) cases, group 2: (20-25 mg/dl) -17(15.7%), and group 3: (>25 mg/dl) -6(5.5%). Developmental assessment was done using DASII at 3, 6, 9, 12 months of age.

RESULTS

Out of 108 cases, 101(93.5%) received phototherapy, and 7(6.5%) received double volume exchange transfusion. Severe delay was observed in 5(4.6%) and mild delay in 2(1.9%) cases in the motor domain of DASII at one year. Severe delay in the motor domain was associated with mean TSB of 27.940±2.89 mg/dl and mild delay with mean TSB of 22.75±1.76 mg/dl (p = 0.001). On cluster analysis, delay was observed in locomotion 1 score in 11(13%) cases (p = 0.003) and manipulation score in 6(7.1%) cases in group 1.

CONCLUSION

Increased serum bilirubin was a significant risk factor for the delayed neurodevelopment in babies with neonatal jaundice. Even a moderate level of bilirubin significantly affects the developmental outcome.

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

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

Comparison of Diagnostic Accuracy of Different Sites for Transcutaneous Bilirubin Measurement in Early Preterm Infants

OBJECTIVE

To evaluate correlation of transcutaneous bilirubin (TcB) measured at different body sites with serum total bilirubin (TSB) in early preterm infants.

METHODS

This hospital based prospective comparative study was carried out in the Department of Pediatrics, SMS Medical College, Jaipur between April 2015 to March 2016. Early preterm infants with gestational age ≤ 34 weeks in whom clinical jaundice was significant mandating TSB measurement were included in the study. Study subjects who met the inclusion criteria were chosen consecutively. Neonates in whom phototherapy was already initiated and those with poor perfusion (capillary refill time > 3 s) were excluded from the study. All the measurements were carried out within first postnatal week. Transcutaneous bilirubin was measured from three sites: forehead, sternum and interscapular region and within 15 min of TcB measurement, blood samples were taken and serum bilirubin level was calculated.

RESULTS

Correlation coefficients of transcutaneous bilirubin measured from forehead, sternum and interscapular sites were 0.82, 0.84 and 0.86 respectively. TcB measured from all the three sites correlated significantly with serum bilirubin (p < 0.001), but the correlation was best at interscapular site. Sensitivity, specificity and false negative rates were calculated with respect to starting phototherapy. Interscapular site had the highest sensitivity and lowest false negative rate (87.6 and 12.4% respectively) as compared to forehead (79.2 and 20.8% respectively) and sternum (87.1 and 12.9% respectively).

CONCLUSIONS

Transcutaneous bilirubin measurement is an acceptable method for identification of hyperbilirubinemia requiring treatment in early preterm newborns. The authors recommend interscapular region as a reliable site in infants of gestational age ≤34 wk for measuring transcutaneous bilirubin.

The smartphone camera as a potential method for transcutaneous bilirubin measurement

BACKGROUND

Hyperbilirubinemia is a common problem in neonates that can progress into kernicterus. Suspected neonatal hyperbilirubinemia is a common reason for contact with the healthcare system. The severity and management of jaundice are determined based on estimated bilirubin levels. However, no easy and accessible tool for self-assessing neonatal jaundice is currently available. Smartphones could potentially be transformed into a medical device that could be used by both patients and practitioners.

OBJECTIVE

To investigate whether a digital image produced by a camera embedded on a smartphone can be a used as a screening tool for neonatal hyperbilirubinemia.

STUDY DESIGN

A total of 64 randomly selected newborns were enrolled. The inclusion criteria were healthy Caucasians, gestational age >35 weeks, age >24 hours and ≤14 days old, and parental informed consent. The exclusion criteria were facial skin lesions and light treatment. Images of the glabella were obtained with an iPhone 6 via i) directly applied pressure, ii) a dermatoscope, or iii) a dermatoscope equipped with a Wratten No. 11 filter. The red, green and blue colour intensities of each image were compared to bilirubin levels.

RESULTS

Only the dermatoscope-acquired intensities of the green and blue channels were significantly correlated (p < 0.001) with bilirubin measurements (Pearson's r: 0.59 and 0.48, respectively). For the green and blue channels, discrimination limits of 212 and 190, respectively, revealed a sensitivity and specificity of 100% and 62.5%, respectively, for green and 90.9% and 60%, respectively, for blue for a plasma bilirubin above 205 μmol/L.

CONCLUSIONS

The results of this study indicate that a smartphone equipped with a consistent light source in the form of a dermatoscope may be a simple screening tool for neonatal hyperbilirubinemia. However, the method requires some improvement before clinical application.

Use of a Smartphone App to Assess Neonatal Jaundice

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transcutaneous bilirubin measurement to estimate serum bilirubin in neonates in a multi-ethnic cohort: a literature review

Neonatal jaundice (NNJ) is common in Singapore and is usually monitored with serum bilirubin (SB). This paper reviews literature on the accuracy of transcutaneous bilirubin (TcB) measurement compared to SB to monitor jaundice in neonates of major ethnic groups of Singapore, i.e. Chinese, Malay, and Indian. 15 studies with Chinese babies, 5 with Malay babies, and 15 with Indian babies were identified (total of 28 articles, some with more than one race). Correlation coefficient is good for all three races. Chest is a better site for TcB measurement than forehead, though both are good. Infants with TcB levels more than 160–200 μmol/L should have SB checked. While post-phototherapy infants may benefit from TcB 24 hours after cessation of phototherapy, more needs to be done to ascertain its usefulness. Premature babies should have SB measurements. TcB measurement is suitable to monitor NNJ in term and healthy Chinese, Malay, and Indian babies.

Utility of Decision Rules for Transcutaneous Bilirubin Measurements

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Discrepancies between transcutaneous and serum bilirubin measurements

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Comparison between Transcutaneous and Total Serum Bilirubin in Healthy-term Greek Neonates with Clinical Jaundice

The accuracy of transcutaneous bilirubin meters has been assessed in newborns from various ethnic backgrounds. However, there are limited data on Greek newborns. Our study examined the accuracy of transcutaneous bilirubin measurements in clinically jaundiced healthy-term Greek newborns, using total serum bilirubin as the reference standard, in order to re-evaluate our local guidelines about neonatal jaundice. Clinically jaundiced newborns requiring total serum bilirubin level estimation were recruited prospectively. 368 pairs of total serum bilirubin/transcutaneous bilirubin measurements were taken in 222 newborns, using a direct spectrophotometric device and the BiliCheck device, respectively. The level of agreement between the obtained transcutaneous bilirubin and total serum bilirubin values was assessed. Our data were analysed using the Stata/SE 12.0 (StataCorp LP, USA) statistical programme. The mean (± SD) TSB was 225.4 ± 25.4 μmol/l and the mean (± SD) TcB was 237.9 ± 21.0 μmol/l. The correlation between the values was poor (Pearson’s correlation coefficient 0.439; Lin’s concordance coefficient 0.377 [95% CI 0.301 to 0.453]; P<0.001). The Bland-Altman analysis demonstrated that transcutaneous bilirubin measurements tended to overestimate the total serum bilirubin value (mean difference 12.5 ± 24.9 μmol/l), with wide 95% limits of agreement (–36.2 μmol/l to 61.3 μmol/l). Transcutaneous bilirubin values did not correlate well with total serum bilirubin values, being often imprecise in predicting the actual total serum bilirubin levels. This permits us to continue estimating total serum bilirubin in clinically jaundiced newborns according to our local guidelines, in order to safely decide the appropriate care plan.

Transcutaneous bilirubinometry

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

Influence of skin colour on diagnostic accuracy of the jaundice meter JM 103 in newborns

AIM

To assess the diagnostic accuracy of the JM 103 as a screening tool for neonatal jaundice and explore differential effects based on skin colour.

METHODS

We prospectively compared the transcutaneous bilirubin (TcB) and serum bilirubin (TSB) measurements of newborns over a 3 month-period. Skin colour was assigned via reference colour swatches. Diagnostic measures of the TcB/TSB comparison were made and clinically relevant TcB cut-off values were determined for each skin colour group.

RESULTS

451 infants (51 light, 326 medium and 74 dark skin colour) were recruited. The association between TcB and TSB was high for all skin colours (rs>0.9). The Bland-Altman analysis showed an absolute mean difference between the two measures of 13.3±26.4 µmol/L with broad limits of agreement (-39.4-66.0 µmol/L), with TcB underestimating TSB in light and medium skin colours and overestimating in dark skin colour. Diagnostic measures were also consistently high across skin colours, with no clinically significant differences observed.

CONCLUSIONS

The JM 103 is a useful screening tool to identify infants in need of serum bilirubin, regardless of skin colour. The effect of skin colour on the accuracy of this device at high levels of serum bilirubin could not be assessed fully due to small numbers in the light and dark groups.

Influence of assessment site in measuring transcutaneous bilirubin

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Transcutaneous bilirubin measurement methods in neonates and its utility for emergency department use

Transcutaneous bilirubin measurements correlate with serum bilirubin measurements in neonates. They permit rapid measurements but do not provide fractionation information. Background information of bilirubin measurements is reviewed. The role of transcutaneous bilirubin measurements in the emergency department is reviewed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Transcutaneous bilirubin nomogram for predicting neonatal hyperbilirubinemia in healthy term and late-preterm Chinese infants

Identifying infants that will develop significant hyperbilirubinemia with the risk of kernicterus, and planning appropriate follow-up strategies, is particularly challenging. In this study, 36,921 transcutaneous bilirubin (TcB) measurements were obtained from 6,035 healthy neonates (gestational age ≥ 35 weeks and birth weight ≥ 2,000 g) between January 1 and December 31, 2009. All measurements were performed with the JM-103 bilirubinometer at designated times between 0 and 168 postnatal hours. TcB percentiles were calculated and used to develop an hour-specific nomogram. The rate of increase in TcB was higher during the first 72 h of age, after which levels declined to a plateau by 72-108 h of age. We constructed a TcB nomogram by using the 40th, 75th, and 95th percentile values of TcB for every 12 h of the studied interval. The 75th percentile curve of the nomogram may be an ideal cutoff point for intensive follow-up of the neonate for hyperbilirubinemia as it carries very high sensitivity (78.7%) and negative predictive value (98.5%). The specificity (45.7%) and positive predictive value (15.5%) decreased to reach their lowest levels at the 40th percentile. Of the neonates in the high-risk zone, 167 (48.8%) infants had persistent subsequent hyperbilirubinemia post-discharge, compared with 292 (27.0%) infants in the high-intermediate-risk zone at discharge. One-hundred and seventeen (5.5%) infants in the low-intermediate-risk zone moved into the high-risk zone during follow-up. No newborn infants in the low-risk zone became high-risk during follow-up. We provide an hour-specific TcB nomogram to predict neonatal hyperbilirubinemia in healthy term and late-preterm Chinese infants.

Implementing and validating transcutaneous bilirubinometry for neonates

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

Hyperbilirubinemia and Transcutaneous Bilirubinometry

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

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

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