Clinical Analysis of Abnormal Brainstem Auditory Evoked Potential in Neonates with Hyperbilirubinemia.

BACKGROUND: Severe neonatal hyperbilirubinemia can cause hearing impairment. Bilirubin can be deposited in nerve cells, and the brainstem and the 8th nerve are especially sensitive to bilirubin toxicity. Abnormal changes in brainstem auditory evoked potential (BAEP) can be observed, and the BAEP test measures a nerve potential induced by short, high-frequency sound stimulation; thus, it is able to detect damage to the auditory conduction pathway in children. We aimed to identify relationships between clinical features and BAEP abnormalities in children with hyperbilirubinemia and to assess the predictive power of these risk factors for bilirubin-induced neurological damage. METHODS: Children with hyperbilirubinemia were evaluated with BAEP and retrospectively enrolled in the study between January 2012 and December 2018. Multivariate logistic regression was performed to identify independent predictors of BAEP abnormalities. RESULTS: Of the 561 children with hyperbilirubinemia enrolled, the BAEP anomaly group accounted for 198 (35.3%) cases. Except for body weight, there were no significant differences in the general data between the two groups with hyperbilirubinemia (p > 0.05). Univariate analysis showed that prematurity, abnormal umbilical cord, and gestational diabetes during pregnancy were significantly correlated with abnormal BAEP. Multivariate logistic regression analysis identified prematurity (p = 0.001), gestational diabetes (p = 0.03), Premature rupture of membranes (p = 0.013), total serum bilirubin (TSB), bilirubin/albumin (B/A) as independent risk factors for BAEP abnormalities. The prediction accuracy of TSB (Area Under Curve (AUC) = 0.557) and B/A (AUC = 0.566) was low, indicating that abnormal BAEP should be detected by multiple factors. CONCLUSIONS: Multivariate detection is beneficial for predicting the occurrence of auditory nerve injury in patients with hyperbilirubinemia.

Hematological abnormality and associated factors in newborns with hyperbilirubinemia before and after phototherapy at University of Gondar Comprehensive Specialized Hospital.

This study aimed to assess the magnitude of hematological toxicity and associated factors in newborns with hyperbilirubinemia. A cross-sectional study was conducted from April to December 2023. A total of 247 newborns were included. The data were collected using questionnaires and a data extraction sheet. Four 4 ml of blood was collected. A Sysmex KX-21 analyzer was used for blood analysis, and a Mindray BS-240 analyzer was used for bilirubin measurement. The data were entered into Epi-data and analyzed by SPSS. The logistic regression was used. The P value was set at 0.05. Before phototherapy, the hematological toxicities, such as anemia, leucopenia, and thrombocytopenia, were 45.7%, 22.2%, and 6.1%, respectively, whereas after phototherapy, anemia and thrombocytopenia, significantly increased, but the leucopenia, significantly decreased. The risk of developing anemia increased, 3.5, 2.7, and 2.1-fold among newborns with bilirubin > 18 mg/dl, with Rh blood group incompatibility, and treated with intensive phototherapy, respectively. Both low birth weight and intensive phototherapy increased the incidence of thrombocytopenia by 2 and 3.4-fold, respectively. Hematological toxicity was found to be a severe public health issue in newborns. Thus, strict follow-up and early detection of toxicity by considering aggravation factors are necessary.

Considerations for applying emerging technologies in paediatric laboratory medicine.

Emerging technology in laboratory medicine can be defined as an analytical method (including biomarkers) or device (software, applications, and algorithms) that by its stage of development, translation into broad routine clinical practice, or geographical adoption and implementation has the potential to add value to clinical diagnostics. Paediatric laboratory medicine itself may be considered an emerging area of specialisation that is established relatively recently following increased appreciation and understanding of the unique physiology and healthcare needs of the children. Through four clinical (neonatal hypoglycaemia, neonatal hyperbilirubinaemia, sickle cell disorder, congenital adrenal hyperplasia) and six technological (microassays, noninvasive testing, alternative matrices, next generation sequencing, exosome analysis, machine learning) illustrations, key takeaways of application of emerging technology for each area are summarised. Additionally, nine key considerations when applying emerging technology in paediatric laboratory medicine setting are discussed.

Bilirubin measurements in neonates: uniform neonatal treatment can only be achieved by improved standardization.

Measurement of total bilirubin (TBil) concentration in serum is the gold standard approach for diagnosing neonatal unconjugated hyperbilirubinemia. It is of utmost importance that the measured TBil concentration is sufficiently accurate to prevent under treatment, unnecessary escalation of care, or overtreatment. However, it is widely recognized that TBil measurements urgently require improvement in neonatal clinical chemistry. External quality assessment (EQA) programs for TBil assess for differences between laboratories and provide supporting evidence of significant differences between various methods, manufacturers and measurement platforms. At the same time, many countries have adopted or only slightly adapted the neonatal hyperbilirubinemia management guidelines from the USA or UK, often without addressing differences in the methodology of TBil measurements. In this report, we provide an overview of the components of bilirubin that are measured by laboratory platforms, the availability of current reference measurement procedures and reference materials, and the role of EQA surveys in this context. Furthermore, the current status of agreement in neonatal bilirubin against clinical decision thresholds is reviewed. We advocate for enhancements in accuracy and comparability of neonatal TBil measurements, propose a path forward to accomplish this, and reflect on the position of the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) Working Group Neonatal Bilirubin (WG-NB) in this matter.

Severe Hemolytic Disease of a Newborn with Bilirubin of 37.3 mg/dL and High anti-A Titer: Corrected with Reconstituted Whole Blood Exchange.

High neonatal bilirubin is a common phenomenon responding to phototherapy. We report a case of a newborn with a highly elevated bilirubin of 37.3 mg/dL due to ABO incompatibility between the mother (Group O) and the newborn (Group A) requiring whole blood exchange, a procedure performed rarely to treat newborn hyperbilirubinemia. The newborn (38.8 weeks of gestation) initially showed a total bilirubin of 8.4 mg/dL and was discharged after being stabilized by phototherapy. However, the baby returned to the hospital with highly elevated bilirubin and was admitted to the Neonatal Intensive Care Unit (NICU). Emergent reconstituted whole blood exchanger therapy was initiated due to refractoriness to phototherapy and IVIG. Markedly elevated anti-A titer was found in the mother's blood (1:512) and cord blood (1:128). The baby was stabilized and eventually discharged with a serum bilirubin of 13.8 mg/dL. This case demonstrates the possible predictive value of mother/cord blood anti-A titers in severe newborn hyperbilirubinemia, which may prevent premature discharge and trigger early initiation of lifesaving therapy.

Effect of hyperbilirubinemia and phototherapy on apoptotic microparticle levels in neonates.

OBJECTIVE: We aimed to evaluate the effect of hyperbilirubinemia and phototherapy on total apoptotic, platelet-derived, endothelial-derived, and tissue factor (TF)-positive apoptotic microparticle (MP) levels in neonates with nonhemolytic pathologic hyperbilirubinemia. METHODS: Thirty-three term neonates with nonhemolytic pathologic hyperbilirubinemia and 25 healthy term neonates were included. MP levels were analyzed by flow cytometry using peripheral blood samples only once for the neonates in the control group and twice for the neonates in the study group (before and after phototherapy). Annexin V-positive MPs were defined as apoptotic MPs. Platelet-derived MPs were defined as those containing CD31. MPs containing CD144 were defined as endothelial-derived MPs, and MPs expressing TF were identified as those containing CD142. RESULTS: The rates of total apoptotic and endothelial-derived apoptotic MPs were significantly higher in the study group than the control group before phototherapy (P = 0.012 and P = 0.003, respectively) and after phototherapy (P = 0.046 and P = 0.001, respectively). Total apoptotic, platelet-derived, endothelial-derived, and TF-positive apoptotic MPs did not show any significant differences before and after phototherapy in the study group (P = 0.908, P = 0.823, P = 0.748, and P = 0.437, respectively). CONCLUSIONS: Our study demonstrated that total apoptotic and endothelial-derived apoptotic MPs are increased in cases of nonhemolytic pathologic hyperbilirubinemia. We showed that phototherapy does not have a significant effect on apoptotic MP levels. Further studies are needed to evaluate the risk of elevated apoptotic MPs on the development of thromboembolism in neonates with nonhemolytic pathologic hyperbilirubinemia.

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

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

[Multicenter evaluation of the diagnostic efficacy of jaundice color card for neonatal hyperbilirubinemia].

Objective: To evaluate the diagnostic efficacy and practicality of the Jaundice color card (JCard) as a screening tool for neonatal jaundice. Methods: Following the standards for reporting of diagnostic accuracy studies (STARD) statement, a multicenter prospective study was conducted in 9 hospitals in China from October 2019 to September 2021. A total of 845 newborns who were admitted to the hospital or outpatient department for liver function testing due to their own diseases. The inclusion criteria were a gestational age of ≥35 weeks, a birth weight of ≥2 000 g, and an age of ≤28 days. The neonate's parents used the JCard to measure jaundice at the neonate's cheek. Within 2 hours of the JCard measurement, transcutaneous bilirubin (TcB) was measured with a JH20-1B device and total serum bilirubin (TSB) was detected. The Pearson's correlation analysis, Bland-Altman plots and the receiver operating characteristic (ROC) curve were used for statistic analysis. Results: Out of the 854 newborns, 445 were male and 409 were female; 46 were born at 35-36 weeks of gestational age and 808 were born at ≥37 weeks of gestational age. Additionally, 432 cases were aged 0-3 days, 236 cases were aged 4-7 days, and 186 cases were aged 8-28 days. The TSB level was (227.4±89.6) µmol/L, with a range of 23.7-717.0 µmol/L. The JCard level was (221.4±77.0) µmol/L and the TcB level was (252.5±76.0) µmol/L. Both the JCard and TcB values showed good correlation (r=0.77 and 0.80, respectively) and agreements (96.0% (820/854) and 95.2% (813/854) of samples fell within the 95% limits of agreement, respectively) with TSB. The JCard value of 12 had a sensitivity of 0.93 and specificity of 0.75 for identifying a TSB ≥205.2 µmol/L, and a sensitivity of 1.00 and specificity of 0.35 for identifying a TSB ≥342.0 µmol/L. The TcB value of 205.2 µmol/L had a sensitivity of 0.97 and specificity of 0.60 for identifying TSB levels of 205.2 µmol/L, and a sensitivity of 1.00 and specificity of 0.26 for identifying TSB levels of 342.0 µmol/L. The areas under the ROC curve (AUC) of JCard for identifying TSB levels of 153.9, 205.2, 256.5, and 342.0 µmol/L were 0.96, 0.92, 0.83, and 0.83, respectively. The AUC of TcB were 0.94, 0.91, 0.86, and 0.87, respectively. There were both no significant differences between the AUC of JCard and TcB in identifying TSB levels of 153.9 and 205.2 µmol/L (both P>0.05). However, the AUC of JCard were both lower than those of TcB in identifying TSB levels of 256.5 and 342.0 µmol/L (both P<0.05). Conclusions: JCard can be used to classify different levels of bilirubin, but its diagnostic efficacy decreases with increasing bilirubin levels. When TSB level are ≤205.2 µmol/L, its diagnostic efficacy is equivalent to that of the JH20-1B. To prevent the misdiagnosis of severe jaundice, it is recommended that parents use a low JCard score, such as 12, to identify severe hyperbilirubinemia (TSB ≥342.0 µmol/L).

Evaluating the relationship between aEEG findings and two-year prognosis in neonates with severe hyperbilirubinemia.

OBJECTIVE: Identifying factors that can better predict the prognosis of neonates with hyperbilirubinemia is important. In this study, we aimed to evaluate the relationship between electroencephalography (EEG) findings and two-year prognosis in neonates with severe hyperbilirubinemia. METHODS & MATERIALS: In a cohort prospective study, we studied neonates with a total serum bilirubin level of higher than 18 mg/dL, who were admitted to the neonatal intensive care unit (NICU) of Ghaem hospital, Mashhad, Iran. EEG was recorded upon admission, for all neonates. Patients' data, including demographic characteristics, admission information, and pregnancy and birth data were gathered by obtaining history from parents and studying case files. Also, the relationship between initial EEG findings and final developmental status was assessed. RESULTS: Mean and standard deviation age of patients were 5.46 ± 3.13 days and average serum total bilirubin level was 23.97 ± 4.34 mg/dL at admission. Our findings revealed a significant correlation between the presence of trace alternant on EEG and developmental delay (P = .001). Presence of trace alternant waves on initial EEG at admission was significantly associated with developmental delay in the two year (P = .005). CONCLUSION: These results indicate a relationship between developmental prognosis and the severity of hyper bilirubinemia in neonates. Also, our findings show that the presence of trace alternate waves on the initial EEG is significantly associated with developmental delay of the neonate in the future.

Comparison of prognosis between hyperbilirubinemic infants with and without hypernatremia.

OBJECTIVES: Hypernatremia may facilitate the diffusion of bilirubin through the blood-brain barrier and increase the risk of bilirubin encephalopathy. This study was conducted to compare the prognosis of jaundice infants with those with jaundice and hypernatremia. METHODS: A total of 615 term infants with idiopathic jaundice with or without hypernatremia were enrolled in this cohort study with 24-months follow-up at Ghaem Hospital, Mashhad, Iran, between 2010 and 2022. An in-house questionnaire including the laboratory evaluation and neonatal characteristics was used as the data collection tool. The follow-up of neonatal development status was performed using the Denver test II at 6, 12, 18, and 24 months after discharging from hospital. RESULTS: Normal outcomes were seen in 555 (90.2%) out of 615 studied infants, while 60 cases (9.8%) showed abnormal outcomes. Serum levels of sodium (P = 0.017), bilirubin (P = 0.001), urea (P = 0.024), and creatinine (P = 0.011) as well as hyperthermia (P = 0.046) and unconsciousness (P = 0.005) showed significant differences between the two groups. Approximately 16% of the newborns with both jaundice and hypernatremia, and 9% of those with only jaundice had unfavorable prognoses. Also, bilirubin level had the most predictive power (91.3%). CONCLUSIONS: Our results suggest that hypernatremia or jaundice alone, may affect the prognosis of infants aged 2 years; but jaundice and hypernatremia together, will intensify the developmental problems in jaundice infants. However, the role of hyperbilirubinemia in the incidence of complications is more than hypernatremia.

End-tidal carbon monoxide concentrations measured within 48 hours of birth predict hemolytic hyperbilirubinemia.

OBJECTIVES: To determine, among neonates at-risk for hyperbilirubinemia, whether measuring end-tidal carbon monoxide concentration (ETCOc) twice before 48 hours could identify those who would develop hyperbilirubinemia and differentiate hemolytic vs. non-hemolytic causes. METHODS: Prospective study on neonates meeting criteria "at-risk for hyperbilirubinemia." Routine bilirubin measurements and 10-day follow-up were used to categorize neonates as; (1) normal (no hyperbilirubinemia, all bilirubins <95th percentile of Bhutani nomogram), (2) having hemolytic hyperbilirubinemia (bilirubin ≥95th percentile, DAT+, elevated retic, or G6PD+), or (3) having non-hemolytic hyperbilirubinemia. RESULTS: 386 neonates were enrolled. 321 (83%) did not develop hyperbilirubinemia and 65 (17%) did, of which 29 were judged hemolytic and 36 non-hemolytic. High ETCOc differentiated the hemolytic group (p < 0.001). First-day ETCOc correlated with bilirubin and with reticulocyte count (r = 0.896 and 0.878) and sensitivity and specificity for predicting hyperbilirubinemia were excellent (83% and 95%). CONCLUSIONS: ETCO measurement in the first 48 hours after birth predicts hemolytic hyperbilirubinemia.

Hyperbilirubinemia screening and treatment in neonates born prior to 35 weeks of gestation.

BACKGROUND: Guidelines on when to screen for neonatal hyperbilirubinemia apply to infants born at 35 weeks or later of gestation. It is unknown whether infants born earlier would benefit from similar guidelines. Our objective was to examine hyperbilirubinemia screening and phototherapy prescription among early preterm infants during the first 6 days of life. METHODS: We reviewed the charts of 193 infants born prior to 35 weeks of gestation who were admitted to a tertiary care NICU in Southeastern Ontario in 2018-2019. Information on total serum bilirubin (TSB) measurements over each 12-hour interval during the first six days of life and the treatment decision (no treatment, initiate, continue, or stop phototherapy) was extracted. We also examined what proportion of infants were prescribed phototherapy during each 12-hour interval. RESULTS: Of 1006 TSB measurements performed over the first 6 days of life, 605 were done to determine whether phototherapy should be initiated. Treatment was prescribed in 275 instances (45%). A higher proportion of infants born prior to 28 weeks of gestation required phototherapy in the first 12 hours of life (37%) compared to those born at 28-32 weeks (20%) and 33-34 weeks (5.7%). CONCLUSIONS: Our results suggest that TSB measurements are often poorly timed to detect treatment need in infants born prior to 35 weeks of gestation. This unnecessarily increases the risk of complications from phlebotomy and is an ineffective use of health care resources. There is a need to develop guidelines to optimize hyperbilirubinemia screening among early preterm infants.

Pre-phototherapy total serum bilirubin levels in extremely preterm infants.

BACKGROUND: Extremely preterm infants are prone to hyperbilirubinemia and its sequelae. Currently recommended thresholds for initiating phototherapy in these newborns are consensus-based (CB). METHODS: A multi-site retrospective cohort study of 642 infants born at 240/7 to 286/7 weeks' gestation, between January 2013 and June 2017, was conducted at three NICUs in Canada. Pre-phototherapy TSB percentile levels at 24 h of age were generated and contrasted with published CB thresholds. RESULTS: Among infants born 240/7 to 256/7 weeks' gestation, the differences between our TSB percentiles vs. the CB threshold of 85.0 µmol/L were 10.0 µmol/L (95% CI, 6.0-16.0) at the 75th percentile and 35.3 µmol/L (95% CI, 26.1-42.8) at the 95th percentile. Respectively, among infants born at 260/7 to 276/7 weeks, differences were 19.4 µmol/L (95% CI, 16.8-23.4) and 43.3 µmol/L (95% CI, 34.7-46.9). Born at 280/7 to 286/7 weeks' gestation, differences between our 75th and 95th TSB percentiles and the CB threshold of 103 µmol/L were 6.9 µmol/L (95% CI, 3.2-12.0) and 36.0 µmol/L (95% CI, 31.0-44.3), respectively. CONCLUSIONS: We provide statistically derived pre-phototherapy TSB levels that may clarify patterns of pre-phototherapy TSB levels in extremely preterm infants. IMPACT: We present statistically derived pre-phototherapy total serum bilirubin levels in a cohort of extremely preterm infants. Most of these preterm infants received phototherapy-some at below currently published thresholds. There are notable differences between our statistically derived pre-phototherapy TSB levels and currently published lower limit TSB thresholds for phototherapy. Our study results assist in the understanding of pre-phototherapy TSB levels in extremely preterm infants.

High levels of pathological jaundice in the first 24 hours and neonatal hyperbilirubinaemia in an epidemiological cohort study on the Thailand-Myanmar border.

Population risks for neonatal hyperbilirubinaemia (NH) vary. Knowledge of local risks permits interventions that may reduce the proportion becoming severe. Between January 2015 and May 2016, in a resource-limited setting on the Thailand-Myanmar border, neonates from 28 weeks' gestation were enrolled into a prospective birth cohort. Each neonate had total serum bilirubin measurements: scheduled (24, 48, 72 and 144 hours of life) and clinically indicated; and weekly follow up until 1 month of age. Risk factors for developing NH were evaluated using Cox proportional hazard mixed model. Of 1710 neonates, 22% (376) developed NH (83% preterm, 19% term). All neonates born <35 weeks, four in five born 35-37 weeks, and three in twenty born ≥38 weeks had NH, giving an overall incidence of 249 per 1000 livebirths [95%CI 225, 403]. Mortality from acute bilirubin encephalopathy was 10% (2/20) amongst the 5.3% (20/376) who reached the severe NH threshold. One-quarter (26.3%) of NH occurred within 24 hours. NH onset varied with gestational age: at a median [IQR] 24 hours [24, 30] for neonates born 37 weeks or prematurely vs 59 hours [48, 84] for neonates born ≥38 weeks. Risk factors for NH in the first week of life independent of gestational age were: neonatal G6PD deficiency, birth bruising, Sgaw Karen ethnicity, primigravidae, pre-eclampsia, and prolonged rupture of membranes. The genetic impact of G6PD deficiency on NH was partially interpreted by using the florescent spot test and further genotyping work is in progress. The risk of NH in Sgaw Karen refugees may be overlooked internationally as they are most likely regarded as Burmese in countries of resettlement. Given high levels of pathological jaundice in the first 24 hours and overall high NH burden, guidelines changes were implemented including preventive PT for all neonates <35 weeks and for those 35-37 weeks with risk factors.

High levels of unbound bilirubin are associated with acute bilirubin encephalopathy in post-exchange transfusion neonates.

BACKGROUND: Although it is known that unbound bilirubin can enter the brain, there is little evidence of its association with the development of acute bilirubin encephalopathy. Here, we investigated this potential relationship in neonates who had undergone exchange transfusion. METHODS: Data from 46 newborns who underwent exchange transfusion between 2016 and 1-1 to 2018-12-31 at the First People's Hospital of Changde City in China were analyzed. The unbound bilirubin level was taken as the independent variable and the development of the acute bilirubin encephalopathy as the dependent variable. The covariates were age, birth weight, sex, red blood cell count, blood glucose, hemolytic disease, and whether the infant had received phototherapy. RESULTS: The mean age and gestational age of the neonates were 146.5 ± 86.9 h and 38.6 ± 1.3 weeks [38.7(34.6-41.1) weeks] old, respectively; 52.17% were male. Binary logistic regression analysis after adjustment for covariates showed a positive association between the levels of unbound bilirubin and the development of acute bilirubin encephalopathy (odds ratio = 1.41, 95% confidence intervals 1.05-1.91, P = < 0.05). CONCLUSION: There is a significant association between unbound bilirubin levels and the development of acute bilirubin encephalopathy in neonates. Further investigations are required to explore the mechanisms.

Improvement Initiative: End-Tidal Carbon Monoxide Measurement in Newborns Receiving Phototherapy.

OBJECTIVES: To determine, as part of our Utah Newborn Nursery Bilirubin Management Program, whether end-tidal carbon monoxide concentration (ETCOc) measurements in all newborns in our nursery receiving phototherapy were associated with outcomes related to the management of hyperbilirubinemia, including time (hours after birth) when phototherapy was initiated, total duration of phototherapy during the nursery stay, repeat phototherapy treatments, and hospital readmission for phototherapy. STUDY DESIGN: We performed a planned interim analysis of a component of our program in which we measured ETCOc noninvasively using CoSense on each newborn in our nursery receiving phototherapy and recorded specific outcomes related to phototherapy management. RESULTS: Of 1856 newborns admitted to our nursery in a 6-month period in 2020, 170 (9.8%) were treated with phototherapy. An ETCOc reading was successfully obtained in 145 of 151 attempts (96%). Higher ETCOc values were associated with earlier institution of phototherapy and longer duration of phototherapy. For every 1-ppm increase in ETCOc, phototherapy was started 9 hours earlier (95% CI, 3.3-14.8; P = .002) and was administered for an additional 9.3 hours (95% CI, 4.1-14.6; P < .001). Three newborns were readmitted to the hospital for intensive phototherapy; while in the nursery, all 3 had an elevated ETCOc (2.2, 2.6, and 2.9 ppm). CONCLUSIONS: Our findings provide answers to questions raised in the 2004 American Academy of Pediatrics bilirubin guidelines. In our neonatal nursery, measuring ETCOc in all phototherapy recipients was feasible and safe, and the results were associated with multiple aspects of phototherapy management. Higher ETCOc values predicted earlier and longer phototherapy courses.

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

Invasive bilirubin measurements remain the gold standard for the diagnosis and treatment of infants with severe neonatal hyperbilirubinemia. The present paper describes different methods currently available to assess hyperbilirubinemia in newborn infants. Novel point-of-care bilirubin measurement methods, such as the BiliSpec and the Bilistick, would benefit many newborn infants, especially in low-income and middle-income countries where the access to costly multi-analyzer in vitro diagnostic instruments is limited. Total serum bilirubin test results should be accurate within permissible limits of measurement uncertainty to be fit for clinical purposes. This implies correct implementation of internationally endorsed reference measurement systems as well as participation in external quality assessment programs. Novel analytic methods may, apart from bilirubin, include the determination of bilirubin photoisomers and bilirubin oxidation products in blood and even in other biological matrices. IMPACT: Key message: Bilirubin measurements in blood remain the gold standard for diagnosis and treatment of severe neonatal hyperbilirubinemia (SNH). External quality assessment (EQA) plays an important role in revealing inaccuracies in diagnostic bilirubin measurements. What does this article add to the existing literature? We provide analytic performance data on total serum bilirubin (TSB) as measured during recent EQA surveys. We review novel diagnostic point-of-care (POC) bilirubin measurement methods and analytic methods for determining bilirubin levels in biological matrices other than blood. Impact: Manufacturers should make TSB test results traceable to the internationally endorsed total bilirubin reference measurement system and should ensure permissible limits of measurement uncertainty.

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

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

Potential of therapeutic bile acids in the treatment of neonatal Hyperbilirubinemia.

Neonatal hyperbilirubinemia or jaundice is associated with kernicterus, resulting in permanent neurological damage or even death. Conventional phototherapy does not prevent hyperbilirubinemia or eliminate the need for exchange transfusion. Here we investigated the potential of therapeutic bile acids ursodeoxycholic acid (UDCA) and obeticholic acid (OCA, 6-α-ethyl-CDCA), a farnesoid-X-receptor (FXR) agonist, as preventive treatment options for neonatal hyperbilirubinemia using the hUGT1*1 humanized mice and Ugt1a-deficient Gunn rats. Treatment of hUGT1*1 mice with UDCA or OCA at postnatal days 10-14 effectively decreased bilirubin in plasma (by 82% and 62%) and brain (by 72% and 69%), respectively. Mechanistically, our findings indicate that these effects are mediated through induction of protein levels of hUGT1A1 in the intestine, but not in liver. We further demonstrate that in Ugt1a-deficient Gunn rats, UDCA but not OCA significantly decreases plasma bilirubin, indicating that at least some of the hypobilirubinemic effects of UDCA are independent of UGT1A1. Finally, using the synthetic, non-bile acid, FXR-agonist GW4064, we show that some of these effects are mediated through direct or indirect activation of FXR. Together, our study shows that therapeutic bile acids UDCA and OCA effectively reduce both plasma and brain bilirubin, highlighting their potential in the treatment of neonatal hyperbilirubinemia.