Transcutaneous bilirubinometry is not influenced by term or skin color in neonates

Machine Learning to Improve Accuracy of Transcutaneous Bilirubinometry

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Skin color influences transcutaneous bilirubin measurements: a systematic in vitro evaluation

OBJECTIVE

Concerns have been raised about the effect of skin color on the accuracy of transcutaneous bilirubin (TcB) measurements, a widely used method for hyperbilirubinemia diagnosis in newborns. Literature is inconclusive, with both reported under- and overestimations of the TcB with increasing skin pigmentation. Therefore, the influence of skin color on TcB measurements was systematically evaluated in a controlled, in vitro setting.

METHODS

A bilirubin meter (JM-105) was evaluated on layered phantoms that mimic neonatal skin with varying dermal bilirubin concentrations (0-250 µmol/L) and varying epidermal melanosome volume fractions (0-40%; light-dark skin color).

RESULTS

TcB measurements were influenced by skin pigmentation. Larger mimicked melanosome volume fractions and higher bilirubin levels led to larger underestimations of the measured TcB, compared to an unpigmented epidermis. In the in vitro setting of this study, these underestimations amounted to 26-132 µmol/L at a TcB level of 250 µmol/L.

CONCLUSION

This in vitro study provides insight into the effect of skin color on TcB measurements: the TcB is underestimated as skin pigmentation increases and this effect becomes more pronounced at higher bilirubin levels. Our results highlight the need for improved TcB meter design and cautious interpretation of TcB readings on newborns with dark skin.

IMPACT

Key message: Skin color influences transcutaneous bilirubin measurements: the darker the skin, the larger the underestimation. What this study adds to existing literature: Existing literature is inconclusive regarding the influence of skin color on transcutaneous bilirubin measurements. This study systematically evaluates and clarifies the influence of skin color on transcutaneous bilirubin measurements in a controlled, in vitro setting.

IMPACT

This study aids to better interpret the measured TcB level in patients with varying skin colors, and is particularly important when using TcB meters on patients with dark skin colors.

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.

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.

Quantification of cephalocaudal progression of jaundice in preterm infants

BACKGROUND

The cephalocaudal progression (CCP) of neonatal jaundice is a well-known phenomenon, but quantitative information on CCP in preterm infants is absent. In this study, CCP was quantified in preterm infants as a function of postnatal age and body location.

METHODS

5.693 transcutaneous bilirubin (TcB) measurements were performed in 101 preterm infants from birth until postnatal day seven at five body locations (forehead, sternum, hipbone, tibia, ankle). Multi-level linear regression analysis was performed to evaluate the CCP as a function of body location and postnatal age. TcB measurements at all body locations and postnatal days were compared to total serum bilirubin (TSB) levels (N = 1.113).

RESULTS

The overall average change in ratio of TcB compared to forehead was for sternum +0.04 [95% CI -0.02;0.09]; hipbone +0.05 [0.00;0.01]; tibia -0.33 [-0.38;-0.27] and ankle -0.62 [-0.68;-0.57]. No effect modification of CCP by sex, gestational age, birthweight, phototherapy, and TSB was found. The TcB maximally underestimated the TSB at the ankle -79.5 µmol [-0.1;159.2].

CONCLUSIONS

CCP is present in preterm infants and is relatively stable over time. Since TcB measurements on the tibia and ankle underestimate TSB significantly, we advise to use only measurement locations cephalic from the tibia; i.e., hipbone, sternum, and forehead.

IMPACT

Cephalocaudal progression (CCP) of jaundice in preterm infants, assessed by transcutaneous bilirubin (TcB) measurements, is substantial and rather stable over postnatal day 0 to 7. To the best of our knowledge, this study is the first to investigate CCP of jaundice in preterm infants as a function of postnatal age in preterm infants. Our results demonstrate that TcB measurements at the tibia and ankle differ from the TSB beyond the clinically used TcB safety margins. We advise to perform TcB measurements only at locations cephalic from the tibia; i.e., hipbone, forehead, and sternum.

A Prospective Comparison of Serum and Transcutaneous Bilirubin in Indian Neonates

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Bilirubin estimates from smartphone images of newborn infants' skin correlated highly to serum bilirubin levels

AIM

Neonatal jaundice is an important cause of morbidity and mortality, and identifying the condition remains a challenge. This study evaluated a novel method of estimating bilirubin levels from colour-calibrated smartphone images.

METHODS

A cross-sectional prospective study was undertaken at two hospitals in Norway from February 2017 to March 2019, with standardised illumination at one hospital and non-standardised illumination at the other hospital. Healthy term-born infants with a normal birthweight were recruited up to 15 days of age. The main outcome measures were bilirubin estimates from digital images, plus total bilirubin in serum (TSB) and transcutaneous bilirubin (TcB).

RESULTS

Bilirubin estimates were performed for 302 newborn infants, and 76 had severe jaundice. The correlation between the smartphone estimates and TSB was measured by Pearson's r and was .84 for the whole sample. The correlation between the image estimates and TcB was 0.81. There were no significant differences between the hospitals. Sensitivity was 100%, and specificity was 69% for identifying severe jaundice of more than 250 µmol/L.

CONCLUSION

A smartphone-based tool that estimated bilirubin levels from digital images identified severe jaundice with high sensitivity and could provide a screening tool for neonatal jaundice.

The accuracy of transcutaneous bilirubin to identify hyperbilirubinemia in jaundiced neonates

OBJECTIVE

To compare transcutaneous bilirubin (TcB) to total serum bilirubin (TSB) in jaundiced neonates by using a JM-103 bilirubinometer.

METHODS

We conducted a retrospective study in jaundiced infants ≥35 weeks' gestation. Infants' and maternal information, TcB measurements, and TSB levels were collected. The correlation and consistency between TcB and TSB were analyzed by Pearson's correlation analysis and the Bland-Altman plot. Multivariate regression analysis was used to identify characteristics associated with the difference between TcB and TSB, underestimation by TcB and overestimation by TcB.

RESULTS

A total of 787 paired samples were collected. There was a strong correlation between TcB and TSB with a Pearson correlation coefficient of 0.708 (p < .001). In preterm infants, outpatients and infants with high TSB levels, the TcB measurements were less precise. The TcB-TSB difference was significantly associated with gender, maternal hypertension disease, ABO hemolytic disease, and outpatient setting (p < .05). Only the outpatient setting had statistical significance in the underestimation of TSB ≥2 mg/dL.

CONCLUSIONS

Generally, TcB by a JM-103 bilirubinometer had a good correlation and consistency with the TSB values. However, small for gestational age, postnatal age of hour, ABO hemolytic disease, and outpatient setting may lead to inconsistencies between the TcB and TSB.

Validation of a neonatal skin color scale

Ethnic classification does not correlate well with skin tone. As there are no neonatal skin color scales, we aimed to create and validate one of our own. After creating the scale and briefly training our staff, we conducted a prospective, observational study to assess reproducibility and correlation of each scale color with the melanin and erythema indexes and transcutaneous bilirubin. The reliability of our color scale was measured using Kappa agreement (and its 95% confidence interval) and the concordance index by comparing inter-observer classification of neonatal skin color. We also calculated inter-rater agreement with the intraclass correlation coefficient (ICC). The Kendall tau-b correlation coefficient was used to test the correlation between our color scale and the Mexameter® MX 18. We obtained data from 258 newborns. Inter-observer agreement on color assignment was 83.2%. Median melanin index was significantly different among the 4 color groups, whereas erythema index and transcutaneous bilirubin were not.Conclusions: Our proposed neonatal skin color scale correlates well with the melanin index at 24 h of life, increasing from colors 1 to 4, and the only chromophore different among our four color groups is melanin. Scale color assignment is reproducible. Therefore, it can be used to classify neonatal skin color. Further research is warranted to assess the clinical relevance of these findings. What is known: • Classifying neonates by skin color is difficult because to date there are no skin color scales available based on real skin tone regardless of ethnicity or country of origin. • Skin color differs among individuals from a given ethnic group and depends, among others, on melanin and hemoglobin. What is new: • We created a neonatal skin color scale based on real skin color. • We conducted a study to validate it, and confirmed a good inter-observer agreement in color assignment as well as a good correlation between each color in the scale and the median melanin level.

Smartphone screening for neonatal jaundice via ambient-subtracted sclera chromaticity

Jaundice is a major cause of mortality and morbidity in the newborn. Globally, early identification and home monitoring are significant challenges in reducing the incidence of jaundice-related neurological damage. Smartphone cameras are promising as colour-based screening tools as they are low-cost, objective and ubiquitous. We propose a novel smartphone method to screen for neonatal jaundice by imaging the sclera. It does not rely on colour calibration cards or accessories, which may facilitate its adoption at scale and in less economically developed regions. Our approach is to explicitly address three confounding factors in relating colour to jaundice: (1) skin pigmentation, (2) ambient light, and (3) camera spectral response. (1) The variation in skin pigmentation is avoided by imaging the sclera. (2) With the smartphone screen acting as an illuminating flash, a flash/ no-flash image pair is captured using the front-facing camera. The contribution of ambient light is subtracted. (3) In principle, this permits a device- and ambient-independent measure of sclera chromaticity following a one-time calibration. We introduce the concept of Scleral-Conjunctival Bilirubin (SCB), in analogy with Transcutaneous Bilirubin (TcB). The scleral chromaticity is mapped to an SCB value. A pilot study was conducted in the UCL Hospital Neonatal Care Unit (n = 37). Neonates were imaged using a specially developed app concurrently with having a blood test for total serum bilirubin (TSB). The better of two models for SCB based on ambient-subtracted sclera chromaticity achieved r = 0.75 (p<0.01) correlation with TSB. Ambient subtraction improved chromaticity estimates in proof-of-principle laboratory tests and screening performance within our study sample. Using an SCB decision threshold of 190μmol/L, the sensitivity was 100% (specificity 61%) in identifying newborns with TSB>250μmol/L (area under receiver operating characteristic curve, AUROC, 0.86), and 92% (specificity 67%) in identifying newborns with TSB>205μmol/L (AUROC 0.85). These results are comparable to modern transcutaneous bilirubinometers.

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.

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

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

Cost savings with transcutaneous screening versus total serum bilirubin measurement for newborn jaundice in hospital and community settings: a cost-minimization analysis

BACKGROUND

Leading authorities in North America recommend universal screening via total serum bilirubin (TSB) measurement or transcutaneous bilirubinometry (TcB) for kernicterus prevention. We assessed costs associated with these 2 screening methods in hospital and in urban and rural community settings.

METHODS

Our tertiary care centre in Saskatoon, with about 5600 births per year, serves the local population of 300 000; in addition, 30% of patients are referred from outside the local community and surrounding area. We obtained health administrative data for two 6-month periods: before (June 1 to Nov. 30, 2015 [TSB program]) and after (June 1 to Nov. 30, 2016 [TcB-TSB program]) implementation of universal screening with TcB. Data on nurses' time and mileage were collected to assess the mean time for screening and sample transportation. We performed a cost-minimization analysis.

RESULTS

The observed requirement for TSB blood draws decreased by 71.4% after implementation of TcB (1383.2/1000 live births to 397.8/1000 live births), whereas the overall number of screens increased from 1383.2 to 2758.6/1000 live births. The mean time per screen decreased from 12.52 (95% confidence interval [CI] 10.44-14.59) minutes with TSB to 2.94 (95% CI 2.55-3.33) minutes with TcB (p < 0.001). The estimated cost per TcB screen in hospital and community (urban and rural) settings was $3.54 and $3.76, respectively, and the estimated cost per TSB screen in hospital and in urban and rural community settings was $15.82, $50.21 and $65.03, respectively. The estimated overall 6-month savings with the TcB-TSB hospital and community programs were $19 760 and $6417, respectively.

INTERPRETATION

The TcB-TSB program reduced nurses' time to screen and provided immediate results at the point of care. Transcutaneous bilirubinometry reduced the requirement for painful heel pokes while improving access to screening and decreasing the overall program cost.

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.

Comparison of Transcutaneous and Serum Bilirubin Measurements in Neonates 30 to 34 Weeks' Gestation Before, During, and After Phototherapy

BACKGROUND

The use of noninvasive, transcutaneous bilirubin monitoring (TcB) as a jaundice screen in full-term infants is well established; however, there is a paucity of research evaluating the use of TcB in premature infants.

PURPOSE

To compare agreement and consistency of transcutaneous and serum bilirubin measurements in a multiracial premature infant population ranging from 30 to 34(Equation is included in full-text article.)weeks' gestation before, during, and after phototherapy.

METHODS

Forty-five neonates, 30 to 34(Equation is included in full-text article.)weeks' gestation, were enrolled in this prospective, correlational study over a 12-month period. One set of paired transcutaneous and serum bilirubin measurements, per neonate, was obtained before phototherapy, during therapy, and after phototherapy. Exclusion criteria included neonates with positive direct coombs test or evidence of hemolytic disease, major congenital anomalies, hydrops fetalis, and those not expected to survive.

RESULTS

There was a strong, positive correlation between TcB and total serum monitoring (TSB) measurements obtained pretherapy (r = 0.797, P < .001). A moderate correlation was noted between TcB and TSB measurements obtained during therapy (r = 0.588, P < .001). A strong correlation was noted between TcB and TSB measurements obtained posttherapy (r = 0.869, P < .001). There were no significant differences between paired samples across time (F = 0.891, P = .41, partial η = 0.01). The TSB measurements were consistently lower than TcB pretherapy, during, and posttherapy.

IMPLICATIONS FOR PRACTICE

The TcB measurements provide a reliable estimation, generally within 2 to 3 mg/dL of TSB levels, in premature infants 30 to 34(Equation is included in full-text article.)weeks' gestation.

IMPLICATIONS FOR RESEARCH

Investigation of consumption of time and nursing personnel required to perform TcB testing, compared with TSB testing, is indicated. Cost analyses comparing TcB-driven screening protocols and interval TSB measurements, among premature infants, are indicated. As newer generations of TcB devices are approved for use, additional studies using mixed-race populations of premature infants will be necessary to continue to evaluate the reliability and validity of this screening tool within the everyday neonatal intensive care unit.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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