Detection of hyperbilirubinaemia in jaundiced full-term neonates by eye or by bilirubinometer?

Ocular manifestations of liver disease: an important diagnostic aid

PURPOSE

This review examined existing literature to determine various ocular manifestations of liver pathologies, with a focus on metabolic deficiencies as well as viral and immune liver conditions.

METHODS

Recent data were compiled from PubMed from 2000 to 2020 using keywords that were relevant to the assessed pathologies. Ocular presentations of several liver pathologies were researched and then summarized in a comprehensive form.

RESULTS

Several ocular manifestations of liver disease were related to vitamin A deficiency, as liver disease is associated with impaired vitamin A homeostasis. Alcoholic liver cirrhosis can result in vitamin A deficiency, presenting with Bitot spots, xerosis, and corneal necrosis. Congenital liver diseases such as mucopolysaccharidoses and peroxisomal disorders are also linked with ocular signs. Viral causes of liver disease have associations with conditions like retinal vasculitis, keratoconjunctivitis sicca, retinopathies, Mooren's ulcer, and Sjogren's syndrome. Autoimmune hepatitis has been linked to peripheral ulcerative keratitis and uveitis.

CONCLUSIONS

Building strong associations between ocular and liver pathology will allow for early detection of such conditions, leading to the early implementation of management strategies. While this review outlines several of the existing connections between hepatic and ophthalmic disease, further research is needed in the area in order to strengthen these associations.

Validity of BiliDx as a point-of-care bilirubin measurement device to diagnose and monitor neonatal jaundice at Muhimbili National Hospital, an observational study

BACKGROUND

Neonatal jaundice is a condition caused by elevated levels of bilirubin in the bloodstream. Laboratory determination of serum bilirubin concentration by total serum bilirubin (TSB) test is still considered as gold standard for clinical guidance and practice. In developed countries, diagnosis of neonatal jaundice is shifting towards point-of-care medical devices. BiliDx is a device developed to allow a fast, blood-based determination of bilirubin levels at the point of care. This study aimed to determine the accuracy of the BiliDx device relative to a standard laboratory total serum bilirubin to diagnose and monitor jaundice among neonates admitted at Muhimbili National Hospital (MNH).

MATERIAL AND METHODOLOGY

This was a prospective hospital-based observational study conducted at the Neonatal Ward - MNH, Dar-es-Salaam, Tanzania from November 2022 to January 2023. A total of 180 neonates admitted at the neonatal ward with jaundice and whose parents consented were enrolled in the study. Blood samples were collected; 2 ml of venous blood into the vacutainer bottle for standard laboratory measurement of total serum bilirubin (TSB) and 25µL blood collected into a transfer pipette tube and applied to BiliDx. STATA version 15.1 was used for data analysis.

RESULTS

Out of 180 neonates, 39.4% (71/180) had birth weight between 1500 - 2499.9 g, approximately 2/3rd (120/180) were preterm, 92/180 (51.1%) were males and 100/180 (55.6%) were undergoing phototherapy treatment the moment sample taken. The mean bilirubin concentration was 92 mmol/l for BiliDx and 118 mmol/l for standard laboratory TSB. The minimum and maximum values obtained with BiliDx were, 3.4 and 427.5 mmol/l respectively, compared with 10.7 and 382.1 mmol/l using standard laboratory TSB. A linear relationship and correlation coefficient of 0.8408 (p = 0.000) between BiliDx and standard laboratory TSB was found. The regression analysis showed the presence of constant error [coefficient of BiliDx/slope = 0.91, 95% CI (0.82-0.99), p = 0.000] and random error exclusively [coefficient of constant/y-intercept = 48.52, 95%CI (37.70-59.34), p = 0.000]. The Bland-Altman plot showed an acceptable mean difference of 39.1mmol/l, limits of agreement of -48.3mmol/l to 126.4mmol/l, and 179 points (179/180 = 99.4%) lying inside the limits of agreement.

CONCLUSION

The results support the use of BiliDx for rapid and accurate testing of elevated levels of bilirubin in the bloodstream among neonates since 99.4% of the differences between BiliDx and standard laboratory TSB lie between the lines of agreement.

Modified Kramer's versus Kramer's Method for Clinical Assessment of Jaundice in Term and Near-Term Neonates

OBJECTIVES

To compare the performance of Modified Kramer's and Kramer's methods in terms of agreement with total serum bilirubin (TSB).

METHODS

This cross-sectional study was done in Level-III neonatal unit in New Delhi. Visibly jaundiced neonates born at ≥35 wk of gestation were enrolled and examined by (i) conventional Kramer's, (ii) Modified Kramer's in artificial (MK-A) and (iii) natural daylight (MK-N), and finally sampled for estimation of TSB by point-of-care spectrophotometry. The primary outcomes were agreement of Kramer's and Modified Kramer's with TSB and accuracy in terms of proportion of bilirubin estimates lying within ±2 mg/dL of TSB; secondary outcome was agreement of MK-A and MK-N with TSB.

RESULTS

A total of 144 neonates with median gestation of 37 wk and mean birth weight of 2788 g were enrolled. Bland Altman analysis between Kramer's and TSB yielded mean difference of 1.7 mg/dL, 95% limits of agreement (LOA) -3.1 to 6.6 mg/dL. For Modified Kramer's and TSB, mean difference was -0.02 mg/dL, 95% LOA -4.7 to 4.7 mg/dL under artificial light; 0.02 mg/dL, 95% LOA -4.2 to 4.2 mg/dL under natural daylight. MK-N had highest proportion of bilirubin estimates lying within ±2 mg/dL of TSB (68.7%) as compared to MK-A (59.7%) [OR, 1.77; 95% CI, 1.09 to 2.86] and Kramer's (45.8%) [OR, 1.65; 95% CI, 1.27 to 2.15].

CONCLUSIONS

Though all the three methods had poor agreement with TSB, Modified Kramer's method when performed in natural light had reasonable accuracy, however limited clinical utility, in evaluation of clinical jaundice.

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.

Phantoms for evaluating the impact of skin pigmentation on photoacoustic imaging and oximetry performance

Recent reports have raised concerns of potential racial disparities in performance of optical oximetry technologies. To investigate how variable epidermal melanin content affects performance of photoacoustic imaging (PAI) devices, we developed plastisol phantoms combining swappable skin-mimicking layers with a breast phantom containing either India ink or blood adjusted to 50-100% SO2 using sodium dithionite. Increasing skin pigmentation decreased maximum imaging depth by up to 25%, enhanced image clutter, and increased root-mean-square error in SO2 from 8.0 to 17.6% due to signal attenuation and spectral coloring effects. This phantom tool can aid in evaluating PAI device robustness to ensure high performance in all patients.

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.

Severe neonatal hyperbilirubinaemia: lessons learnt from a national perinatal audit

OBJECTIVES

To describe characteristics of neonates with severe neonatal hyperbilirubinaemia (SNH) and to gain more insight in improvable factors that may have contributed to the development of SNH.

DESIGN AND SETTING

Descriptive study, based on national Dutch perinatal audit data on SNH from 2017 to 2019.

PATIENTS

Neonates, born ≥35 weeks of gestation and without antenatally known severe blood group incompatibility, who developed hyperbilirubinaemia above the exchange transfusion threshold.

MAIN OUTCOME MEASURES

Characteristics of neonates having SNH and corresponding improvable factors.

RESULTS

During the 3-year period, 109 neonates met the eligibility criteria. ABO antagonism was the most frequent cause (43%). All neonates received intensive phototherapy and 30 neonates (28%) received an exchange transfusion. Improvable factors were mainly related to lack of knowledge, poor adherence to the national hyperbilirubinaemia guideline, and to incomplete documentation and insufficient communication of the a priori hyperbilirubinaemia risk assessment among healthcare providers. A priori risk assessment, a key recommendation in the national hyperbilirubinaemia guideline, was documented in only six neonates (6%).

CONCLUSIONS

SNH remains a serious threat to neonatal health in the Netherlands. ABO antagonism frequently underlies SNH. Lack of compliance to the national guideline including insufficient a priori hyperbilirubinaemia risk assessment, and communication among healthcare providers are important improvable factors. Implementation of universal bilirubin screening and better documentation of the risk of hyperbilirubinaemia may enhance early recognition of potentially dangerous neonatal jaundice.

Sixth-Hour Trancutaneous Bilirubin and Need for Phototherapy in DAT Positive Newborns

OBJECTIVES

To characterize the outcomes of ABO incompatible direct antiglobulin test (DAT) positive newborns and determine the predictive ability of a sixth-hour transcutaneous bilirubin (TcB for needing phototherapy ≤24 hours of age.

METHODS

Retrospective, cross-sectional study from May 2013 to March 2017. Of 10 942 consecutive newborns ≥35 weeks estimated gestational age, 829 were ABO incompatible and DAT positive. After excluding for antibodies other than ABO (51), missing data (4), miscategorization of blood type O (1), and duplicate record (1), 772 newborns remained. Of 772, a subsample of 346 newborns with both TcB and total serum bilirubin (TSB) tests within 1 hour of the sixth hour was analyzed to determine the predictive ability.

RESULTS

Phototherapy was required in 281 of 772 (36.4%); 156 (20.2%) in the first 24 hours. There were 10 (1.3%) admissions for hyperbilirubinemia to the NICU for intravenous immunoglobin. Birth weight, infant blood type B, TSB, reticulocyte count, and TcB were all significantly associated with phototherapy ≤24 hours. On multivariate analysis, significant predictors of phototherapy ≤24 hours were TSB and reticulocyte count if no TcB was done and TcB alone if no blood tests were done. TcB was highly predictive (odds ratio 3.1, 95% confidence interval: 2.4-4.0) and nearly as accurate as the TSB and reticulocyte count (area under the curve, 0.90 and 0.96, respectively). Low (<3.0 mg/dL) and high (≥5.3 mg/dL) risk TcB cutoffs demonstrated a negative predictive value of 98% and positive predictive value of 85%, respectively.

CONCLUSIONS

Among high-risk ABO incompatible DAT positive newborns, the sixth-hour TcB is highly predictive of the need for phototherapy ≤24 hours.

Current and emerging technologies for the timely screening and diagnosis of neonatal jaundice

Neonatal jaundice is one of the most common clinical conditions affecting newborns. For most newborns, jaundice is harmless, however, a proportion of newborns develops severe neonatal jaundice requiring therapeutic interventions, accentuating the need to have reliable and accurate screening tools for timely recognition across different health settings. The gold standard method in diagnosing jaundice involves a blood test and requires specialized hospital-based laboratory instruments. Despite technological advancements in point-of-care laboratory medicine, there is limited accessibility of the specialized devices and sample stability in geographically remote areas. Lack of suitable testing options leads to delays in timely diagnosis and treatment of clinically significant jaundice in developed and developing countries alike. There has been an ever-increasing need for a low-cost, simple to use screening technology to improve timely diagnosis and management of neonatal jaundice. Consequently, several point-of-care (POC) devices have been developed to address this concern. This paper aims to review the literature, focusing on emerging technologies in the screening and diagnosing of neonatal jaundice. We report on the challenges associated with the existing screening tools, followed by an overview of emerging sensors currently in pre-clinical development and the emerging POC devices in clinical trials to advance the screening of neonatal jaundice. The benefits offered by emerging POC devices include their ease of use, low cost, and the accessibility of rapid response test results. However, further clinical trials are required to overcome the current limitations of the emerging POC's before their implementation in clinical settings. Hence, the need for a simple to use, low-cost POC jaundice detection technology for newborns remains an unsolved challenge globally.

Impact of skin tone on photoacoustic oximetry and tools to minimize bias

The major optical absorbers in tissue are melanin and oxy/deoxy-hemoglobin, but the impact of skin tone and pigmentation on biomedical optics is still not completely understood or adequately addressed. Melanin largely governs skin tone with higher melanin concentration in subjects with darker skin tones. Recently, there has been extensive debate on the bias of pulse oximeters when used with darker subjects. Photoacoustic (PA) imaging can measure oxygen saturation similarly as pulse oximeters and could have value in studying this bias. More importantly, it can deconvolute the signal from the skin and underlying tissue. Here, we studied the impact of skin tone on PA signal generation, depth penetration, and oximetry. Our results show that subjects with darker skin tones exhibit significantly higher PA signal at the skin surface, reduced penetration depth, and lower oxygen saturation compared to subjects with lighter skin tones. We then suggest a simple way to compensate for these signal differences.

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.

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.

Validity of maternal visual assessment of neonatal jaundice: a hospital-based study in Thailand

BACKGROUND

Hyperbilirubinaemia is a common cause of hospital admission of newborn infants; however, maternal visual assessment of jaundice may reduce unnecessary hospital visits.

AIMS

To investigate the validity of maternal visual assessment of neonatal jaundice to identify infants with hyperbilirubinaemia requiring phototherapy or who have significant hyperbilirubinaemia ≥239.4 µmol/L (14 mg/dL).

METHODS

A prospective study of the diagnostic accuracy of maternal visual assessment of jaundice was conducted at a university hospital in Bangkok. Mothers were trained to assess for neonatal jaundice using their infant's palms as a skin colour reference. Trained mothers who were blinded to transcutaneous bilirubin or serum bilirubin values assessed their infants and reported 'jaundice' or 'no jaundice', and determined jaundice severity using dermal icterus zones. Sensitivity and negative predictive values were used to assess the validity of visual assessment for neonatal jaundice.

RESULTS

In 180 mothers, the median (min/max) transcutaneous or serum bilirubin value in their infants was 177.8 µmol/L (119.7-309.5). The sensitivity and negative predictive values (95% CI) of maternal assessment for detecting hyperbilirubinaemia requiring phototherapy were 91.7% (73.0-99.0) and 96.6% (87.9-99.1), respectively, and for identifying significant hyperbilirubinaemia were 92.9% (76.5-99.1) and 96.6% (87.9-99.1), respectively. The accuracy of maternal report of dermal zones for serum bilirubin levels was only 44.5%. In 56 infants who received a second jaundice assessment, the sensitivity of maternal assessment for detecting increased transcutaneous or serum bilirubin was 93.9% (83.1-98.7).

CONCLUSION

Teaching mothers to visually assess their infants for neonatal jaundice was demonstrated to be feasible.

ABBREVIATIONS

CI, confidence interval; MB, microbilirubin; min/max, minimum/maximum; NPV, negative predictive value; OPD, outpatient department; PPV, positive predictive value; SD, standard deviation; TcB, transcutaneous bilirubin.

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

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

"On Vivo" and Wearable Clinical Laboratory Testing Devices for Emergency and Critical Care Laboratory Testing

BACKGROUND

Point-of-care testing (POCT) devices are designed for clinical laboratory testing at the bedside or near the patient and can significantly reduce the turnaround time for laboratory test results. The next generation for clinical laboratory testing may be devices that are worn or attached to the patient.

CONTENT

POCT devices that are designed where samples are tested directly on the patient include bilirubinometers, pulse oximeters, breathalyzers (for alcohol and, more recently, cannabinoid detection), transcutaneous blood gas analyses, and novel testing applications such as glucose and tumor signatures following surgical excision. The utility of these devices with special reference for use within the intensive care unit and the emergency department is reviewed.

SUMMARY

It is likely that wearable POCT devices will be developed in the future that can meet current and emerging clinical needs. Advancements in biomedical engineering and information technology will be needed in the creation of next-generation devices.

A Novel Whole Spectrum-Based Non-Invasive Screening Device for Neonatal Hyperbilirubinemia

OBJECTIVE

Careful screening of bilirubin level in newborns is mandatory as per American Academy of Pediatrics (2004), to reduce incidents of kernicterus and acute bilirubin encephalopathy. Although, invasive capillary collection of blood and subsequent biochemical test is considered a gold standard for jaundice detection in neonates, transcutaneous bilirubin measurement using various non-invasive instruments is also used sporadically across the globe. The major aim of this study was to develop a non-invasive spectrometry-based technique for measurement of neonatal bilirubin level as an alternative of total serum bilirubin (TSB) test without limitations of other available bilirubinometers.

METHODS

The instrument comprises of a light source and a spectroscopic detector. A light beam from source incident on the neonatal nail plate through optical fibers. The retro reflected light is acquired using the detector. An indigenously developed software is used to acquire and analyze the optical signal and to calculate the bilirubin value. The instrument was calibrated and validated in reference to TSB on 1033 subjects.

MAJOR RESULTS

The result (r = 0.95 and P < 0.001) indicates a strong correlation between the bilirubin value obtained from our method and TSB. Time variant analysis of the subjects undergoing phototherapy provided a good correlation (r = 0.98). The repeatability test result shows the mean coefficient of variation is less than 5.0%.

CONCLUSIONS

The indigenously developed non-invasive technique successfully detects the bilirubin level in newborns under various physiological conditions with high accuracy and precision.

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.

Agreement test of transcutaneous bilirubin and bilistick with serum bilirubin in preterm infants receiving phototherapy

Background

This study compares the minimally invasive Bilistick and a noninvasive method with standard Total Serum Bilirubin (TSB) measurement in preterm newborns receiving phototherapy. We assess the agreement of Transcutaneous Bilirubinometer (TcB) and Bilistick bilirubin measurements with standard TSB measurement in preterm infants receiving phototherapy.

Methods

Bilirubin was measured by using TcB and Bilistick in 94 preterm infants in RSCM Jakarta Neonatal Ward from October 2016 to March 2017, with gestational ages of < 35 weeks, before phototherapy and after 24 and 48 h of phototherapy.

Results

There was significant correlation before, at 24 and 48 h of phototherapy between TSB and either TcB (r = 0.874; r = 0.889; r = 0.878 respectively; p < 0.0001), or Bilistick (r = 0.868; r = 0.877; r = 0.918 respectively; p < 0.0001). The mean difference and limits of agreement before, at 24 and 48 h of phototherapy between TcB and TSB were 0.81 ± 1.51 mg/dL (− 2.14 to 3.77 mg/dL); 0.43 ± 1.57 mg/dL (− 2.66 to 3.51 mg/dL); 0.41 ± 1.58 mg/dL (− 2.69 to 3.50 mg/dL), respectively. For Bilistick they were − 1.50 ± 1.47 mg/dL (− 4.38 to 1.38 mg/dL); − 1.43 ± 1.47 mg/dL (− 4.32 to 1.46 mg/dL); − 1,15 ± 1.31 mg/dL (− 3,72 to 1,42 mg/dL), respectively.

Conclusions

Both methods are reliable for measuring TSB before, during, and after phototherapy in preterm infants. TcB tends to overestimate while Bilistick underestimates TSB.

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.

Indirect neonatal hyperbilirubinemia in hospitalized neonates on the Thai-Myanmar border: a review of neonatal medical records from 2009 to 2014

BACKGROUND

Indirect neonatal hyperbilirubinemia (INH) is a common neonatal disorder worldwide which can remain benign if prompt management is available. However there is a higher morbidity and mortality risk in settings with limited access to diagnosis and care. The manuscript describes the characteristics of neonates with INH, the burden of severe INH and identifies factors associated with severity in a resource-constrained setting.

METHODS

We conducted a retrospective evaluation of anonymized records of neonates hospitalized on the Thai-Myanmar border. INH was defined according to the National Institute for Health and Care Excellence guidelines as 'moderate' if at least one serum bilirubin (SBR) value exceeded the phototherapy threshold and as 'severe' if above the exchange transfusion threshold.

RESULTS

Out of 2980 records reviewed, 1580 (53%) had INH within the first 14 days of life. INH was moderate in 87% (1368/1580) and severe in 13% (212/1580). From 2009 to 2011, the proportion of severe INH decreased from 37 to 15% and the mortality dropped from 10% (8/82) to 2% (7/449) coinciding with the implementation of standardized guidelines and light-emitting diode (LED) phototherapy. Severe INH was associated with: prematurity (< 32 weeks, Adjusted Odds Ratio (AOR) 3.3; 95% CI 1.6-6.6 and 32 to 37 weeks, AOR 2.2; 95% CI 1.6-3.1), Glucose-6-phosphate dehydrogenase deficiency (G6PD) (AOR 2.3; 95% CI 1.6-3.3), potential ABO incompatibility (AOR 1.5; 95% CI 1.0-2.2) and late presentation (AOR 1.8; 95% CI 1.3-2.6). The risk of developing severe INH and INH-related mortality significantly increased with each additional risk factor.

CONCLUSION

INH is an important cause of neonatal hospitalization on the Thai-Myanmar border. Risk factors for severity were similar to previous reports from Asia. Implementing standardized guidelines and appropriate treatment was successful in reducing mortality and severity. Accessing to basic neonatal care including SBR testing, LED phototherapy and G6PD screening can contribute to improve neonatal outcomes.

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 billirubinometry to estimate total serum bilirubin in neonatal jaundice

Background The gold standard for diagnosis of neonatal jaundice is total serum bilirubin (TSB) measurement. This method, however, is invasive, painful, and costly in terms of workload, time, and money. Moreover, repeated blood sampling may lead to significant blood loss, which is of particular concern in preterm infants. To overcome these drawbacks, non-invasive methods of bilirubin measurement have been proposed. Transcutaneous bilirubinometry (TcB) determines the yellowness of the subcutaneous tissue of a newborn infant by measuring the difference between optical densities for light in the blue and green wavelength regions.Objective To evaluate the accuracy of transcutaneous bilirubinometry for estimating TSB levels in neonatal jaundice.Methods Subjects were infants aged < 28 days with jaundice who had never been treated with phototherapy or exchange transfusion. The study was done from February to July 2016 in Mohammad Hoesin Hospital. Subjects underwent transcutaneous bilirubin (TcB) and TSB assays, with a maximum interval of 15 minutes between tests.Results One hundred fifty patients were included in this study. The TcB values > 5 mg/dL were correlated to TSB > 5 mg/dL, with 100% sensitivity and 83.3% specificity. This cut-off point was obtained from a receiver-operator characteristic (ROC) curve with AUC 99.3% (95%CI 97.9 to 100%; P< 0.001).The correlation coefficients (r) for TSB and TcB measurements on the forehead were 0.897 (P<0.001).Conclusion Transcutaneous bilirubinometry can be used to accurately estimate TSB levels in neonatal jaundice, and may be useful in clinical practice as a non-invasive method to reduce blood sampling.

Effect of Phototherapy on the Reliability of Transcutaneous Bilirubin Devices in Term and Near-Term Infants: A Systematic Review and Meta-Analysis

BACKGROUND

Transcutaneous bilirubin (TcB) devices are commonly used for screening of hyperbilirubinemia in term and near-term infants not exposed to phototherapy. However, the accuracy of TcB devices in infants exposed to phototherapy is unclear.

OBJECTIVES

To conduct a systematic review of studies comparing TcB devices with total serum bilirubin (TSB) in infants receiving phototherapy or in the postphototherapy phase.

METHODS

MEDLINE, EMBASE, Cochrane Library, CINAHL and Scopus databases (from inception to May 8, 2014) were searched. Additional citations were identified from the bibliography of selected articles and from the abstracts of conference proceedings. The studies were included if they compared TcB results with TSB in term and near-term infants during phototherapy or after discontinuation of phototherapy. Two reviewers independently assessed studies for inclusion, and discrepancies were resolved with consensus. Risk of bias was assessed using the QUADAS-2 tool.

RESULTS

Fourteen studies were identified. The pooled estimates of correlation coefficients (r) during phototherapy were: covered sites 0.71 (95% CI 0.64-0.77, 11 studies), uncovered sites 0.65 (95% CI 0.55-0.74), 8 studies), forehead 0.70 (95% CI 0.64-0.75, 12 studies) and sternum 0.64 (95% CI 0.43-0.77, 5 studies). Two studies also provided results as Bland-Altman difference plots (mean TcB-TSB differences -29.2 and 30 µmol/l, respectively). The correlation coefficient improved marginally in the postphototherapy phase (r = 0.72, 95% CI 0.64-0.78, 4 studies).

CONCLUSION

We found a moderate correlation between TcB and TSB during phototherapy with a marginal improvement in the postphototherapy phase. Further research is needed before the use of TcB devices can be recommended for these settings.

Screening neonatal jaundice based on the sclera color of the eye using digital photography

A new screening technique for neonatal jaundice is proposed exploiting the yellow discoloration in the sclera. It involves taking digital photographs of newborn infants' eyes (n = 110) and processing the pixel colour values of the sclera to predict the total serum bilirubin (TSB) levels. This technique has linear and rank correlation coefficients of 0.75 and 0.72 (both p<0.01) with the measured TSB. The mean difference ( ± SD) is 0.00 ± 41.60 µmol/l. The receiver operating characteristic curve shows that this technique can identify subjects with TSB above 205 µmol/l with sensitivity of 1.00 and specificity of 0.50, showing its potential as a screening device.

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.

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

BACKGROUND

The utility of transcutaneous bilirubin measurements (TcB) in screening for hyperbilirubinemia in preterm infants (<34 weeks) and in non-white infants remains a matter of debate.

AIM

To evaluate accuracy of TcB in preterm and term infants of different ethnic backgrounds, using a second generation bilirubinometer.

STUDY DESIGN

The Draeger JM-103® device was used to measure TcB. Eighty five measurements of TcB and total serum bilirubin (TSB) were retrospectively compared. Neonates were stratified into groups according to gestational age: <34 weeks (group 1, n=44) and >34 weeks (group 2, n=41), and according to ethnic origin: Caucasians (group A, n=49) and non-Caucasians (group B, n=36). Statistical analysis, using Pearson's correlation coefficient (r) and Bland-Altman analysis were performed to evaluate correlation and agreement between TSB and TcB values. Multiple linear regression was used to control for confounders for TSB values.

RESULTS

Correlation between TSB and TcB was high. Pearson's correlation coefficients were over 0.9 in all groups (0.910, 0.908, 0.916 and 0.934, p<0.0001 in groups 1, 2, A, and B respectively). Bland-Altman plots showed acceptable and close limits of agreements (56.8/-57.7, 54.2/-67.2, 57.7/-55.8, and 51.3/-69.9μmol/L in groups 1, 2, A and B respectively) with a trend for TcB to overestimate TSB in groups 2 and B. Birth term and skin color were not identified as confounding factors for predicting TSB in multiple linear regression.

CONCLUSIONS

TcB measurements using the Draeger JM-103® device correlate significantly with TSB, regardless of term and skin color. Transcutaneous bilirubinometry seems to be a safe and cost-effective screening method for severe hyperbilirubinemia in newborns of different terms and ethnic origins.

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

BACKGROUND AND OBJECTIVE

Transcutaneous bilirubin (TcB) devices are widely used for the estimation of serum bilirubin levels in term and near-term infants. Our objective was to review the diagnostic accuracy of TcB devices in preterm infants.

METHODS

Medline, Embase, Cochrane library, Cumulative Index to Nursing and Allied Health Literature, and Scopus were searched (from database inception date until December 2012). Additional citations were identified by using the bibliographies of selected articles and from conference proceedings. The studies were included if they compared TcB with total serum bilirubin in preterm infants before phototherapy and presented data as correlation coefficients or as Bland-Altman difference plots. Data were extracted by 1 reviewer and checked for accuracy by the second reviewer. An assessment tool (quality assessment of diagnostic accuracy studies) was used for risk of bias assessments.

RESULTS

Twenty-two studies met the inclusion criteria; 21 studies reported results as correlation coefficients, with pooled estimates of r = 0.83 for each site of measurement. Pooled estimates in infants <32 weeks' gestation were similar to the overall preterm population (r = 0.89 [95% confidence interval: 0.82-0.93]). For the 2 commonly used TcB devices (ie, JM103 and BiliCheck), the results were comparable at the forehead site, although the JM103 device exhibited better correlation at the sternum. Analysis of the Bland-Altman plots (13 studies) revealed negligible bias in measurement at the forehead or sternum site by using either the JM-103 or BiliCheck device; however, the JM-103 device exhibited better precision than the BiliCheck (SD for TcB - total serum bilirubin differences: 24.3 and 31.98 µmol/L, respectively).

CONCLUSIONS

The TcB devices reliably estimated bilirubin levels in preterm infants and could be used in clinical practice to reduce blood sampling.

Validity of neonatal jaundice evaluation by primary health-care workers and physicians in Karachi, Pakistan

OBJECTIVE

The purpose of this study was to validate primary health-care workers' and physicians' visual assessment of neonatal hyperbilirubinemia in Karachi, Pakistan.

STUDY DESIGN

We compared primary health-care workers' and physicians' clinical identification of jaundice in infants <60 days old.

RESULT

Primary health-care workers identified 1- to 20-day-old neonates with hyperbilirubinemia > or =15 mg per 100 ml (260 micromol l(-1)) with 83.3% sensitivity and 50.5% specificity; neonates aged 1 to 6 days were identified with 76.2% sensitivity and 60.7% specificity. Physicians identified neonates aged 1 to 20 days with hyperbilirubimemia > or =15 mg per 100 ml (260 micromol l(-1)) with 51.4% sensitivity and 90.7% specificity, and neonates aged 1 to 6 days with 50% sensitivity and 88.5 % specificity. The primary health-care workers' and physicians' assessments showed fair interobserver agreement (kappa statistic 0.29).

CONCLUSION

Primary health-care workers identified hyperbilirubinemic neonates with adequate sensitivity. With proper training and supervision, their assessment could improve the referral of hyperbilirubinemic neonates in low-resource settings in the developing world.

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

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

Comparison of a new transcutaneous bilirubinometer (Bilimed) with serum bilirubin measurements in preterm and full-term infants

Background

The gold standard to assess hyperbilirubinemia in neonates remains the serum bilirubin measurement. Unfortunately, this is invasive, painful, and costly. Bilimed^®, a new transcutaneous bilirubinometer, suggests more accuracy compared to the existing non-invasive bilirubinometers because of its new technology. It furthermore takes into account different skin colours. No contact with the skin is needed during measurement, no additional material costs occur. Our aim was to assess the agreement between the Bilimed^® and serum bilirubin in preterm and term infants of different skin colours.

Methods

The transcutaneous bilirubin measurements were performed on the infant's sternum and serum bilirubin was determined simultaneously. The agreement between both methods was assessed by Pearson's correlation and by Bland-Altman analysis.

Results

A total of 117 measurement cycles were performed in 99 term infants (group1), further 47 measurements in 38 preterm infants born between 34 - 36 6/7 gestational weeks (group 2), and finally 21 measurements in 13 preterm infants born between 28 - 33 6/7 gestational weeks (group 3). The mean deviation and variability (+/- 2SD) of the transcutaneous from serum bilirubin were: -14 (+/- 144) μmol/l; -0.82 (+/- 8.4) mg/dl in group 1, +16 (+/- 91) μmol/l;+0.93(+/- 5.3) mg/dl in group 2 and -8 (+/- 76) μmol/l; -0.47 (+/- 4.4) mg/dl in group 3. These limits of agreement are too wide to be acceptable in a clinical setting. Moreover, there was to be a trend towards less good agreement with increasing bilirubin values.

Conclusion

Despite its new technology the Bilimed^® has no advantages, and more specifically no better agreement not only in term and near-term Caucasian infants, but also in non-Caucasian and more premature infants.

Neonatal jaundice: a critical review of the role and practice of bilirubin analysis

Neonatal jaundice is common, and usually harmless, because of physiological jaundice or breast-feeding. In some neonates unconjugated bilirubin concentration, coupled with other risk factors, is sufficient to allow free bilirubin to cross the blood-brain barrier and cause kernicterus. Another subgroup of infants is jaundiced because of elevated conjugated bilirubin; a marker for a number of pathological conditions. Bilirubin measurement must identify those infants at risk. Transcutaneous bilirubin measurement is increasingly used in healthy infants, especially before early discharge or at home, to assess the need for laboratory bilirubin measurement. Transcutaneous measurements are not covered by laboratory quality assessment schemes. Guidelines on management of neonatal jaundice utilize age in hours and other risk factors to define bilirubin action thresholds, which may be as low as 100 μmol/L for sick premature infants, whereas early discharged babies may only present after bilirubin concentrations are extremely high. Hence, there is a requirement for accurate total bilirubin measurement from <100 to >500 μmol/L, with sufficient precision to assess the rate of bilirubin change with time. Babies presenting with late jaundice always require conjugated bilirubin measurement. It is of concern that many total and direct bilirubin automated kit methods suffer from haemolysis interference, while use of in-house methods or modification of commercial methods has virtually disappeared. External quality assessment has a vital role in providing data on different methods' performance, including accuracy, precision and susceptibility to interference. Laboratories should consider whether their adult bilirubin methods are suitable for neonates.

Is visual assessment of jaundice reliable as a screening tool to detect significant neonatal hyperbilirubinemia?

OBJECTIVE

To assess the reliability of visual assessment of bilirubin levels (BiliEye) in newborns as a screening tool to detect significant neonatal hyperbilirubinemia.

STUDY DESIGN

5 neonatologists and 17 nurses estimated 3,532 BiliEye in 1,129 term and late preterm (> or = 35 weeks) infants before discharge from the nursery, at 62 +/- 24 hours. Total serum bilirubin (TSB) levels were measured concomitantly.

RESULTS

Mean TSB and BiliEye were 6.7 +/- 2.9 mg/dL (range, 0.4-18.2 mg/dL) and 6.6 +/- 3.2 mg/dL (range, 0.0-17.2 mg/dL), respectively, with good correlation (Pearson's r = 0.752, P < .0001), but other measures of agreement were poor. 61.5% of the 109 babies with TSB levels in high-risk zones were clinically misclassified. The area under curve (AUC) of the receiver-operating characteristics plotted for these high-risk zones was 0.825, but became low for early discharge (< or = 36 hours; AUC = 0.638) and late preterm (35-37 weeks; AUC = 0.613). There was significant interobserver variation (low weighted kappa, 0.363).

CONCLUSIONS

Although there was good correlation between BiliEye and actual TSB level, visual assessment was unreliable as a screening tool to detect significant neonatal hyperbilirubinemia before discharge. Babies with TSB levels within high-risk zones may be clinically misdiagnosed as low-risk, resulting in inadequate follow-up.