An evidence-based view on hyperbilirubinaemia

Correlation between hyperbilirubinemia risk and immune cell mitochondria parameters in neonates with jaundice

Purpose

To explore the correlation between mitochondria parameters of immune cells and hyperbilirubinemia risk in hospitalized neonates with jaundice.

Methods

This retrospective study included jaundiced neonates born between September 2020 and March 2022 at Shaoxing Keqiao Women & Children's Hospital. The neonates were divided into low, intermediate-low, intermediate-high, and high-risk groups according to the hyperbilirubinemia risk. The purpose parameters including percentage, absolute count, mitochondrial mass (MM), and single-cell MM (SCMM) of peripheral blood T lymphocytes detected by flow cytometry were collected.

Results

Finally, 162 neonates with jaundice (47, 41, 39, and 35 with low, intermediate-low, intermediate-high, and high-risk) were included. CD3⁺ SCMM was significantly higher in the high-risk group compared with the low and intermediate-low-risk groups (both P < 0.0083), CD4⁺ SCMM was significantly higher in the high-risk group compared with the three other groups (all P < 0.0083), and CD8⁺ SCMM was significantly higher in the intermediate-low and high-risk groups compared with the low-risk group (both P < 0.0083). CD3⁺ (r = 0.34, P < 0.001) and CD4⁺ (r = 0.20, P = 0.010) SCMM positively correlated with bilirubin levels.

Conclusions

The mitochondrial SCMM parameters differed significantly among jaundiced neonates with different hyperbilirubinemia risks. CD3⁺ and CD4⁺ T cell SCMM values were positively correlated with the serum bilirubin levels, and might correlated with hyperbilirubinemia risk.

Parental detection of neonatal jaundice using a low-cost colour card: a multicentre prospective study

BACKGROUND

Since most infants are usually discharged before age 48-72 hours, peak bilirubin levels will almost always occur after discharge. Parents may be the first to observe the onset of jaundice after discharge, but visual assessment is unreliable. The jaundice colour card (JCard) is a low-cost icterometer designed for the assessment of neonatal jaundice. The objective of this study was to evaluate parental use of JCard to detect jaundice in neonates.

METHODS

We conducted a multicentre, prospective, observational cohort study in nine sites across China. A total of 1161 newborns ≥35 weeks of gestation were enrolled in the study. Measurements of total serum bilirubin (TSB) levels were based on clinical indications. The JCard measurements by parents and paediatricians were compared with the TSB.

RESULTS

JCard values of parents and paediatricians were correlated with TSB (r=0.754 and 0.788, respectively). The parents' and paediatricians' JCard values 9 had sensitivities of 95.2% vs 97.6% and specificities of 84.5% vs 71.7% for identifying neonates with TSB ≥153.9 µmol/L. The parents' and paediatricians' JCard values 15 had sensitivities of 79.9% vs 89.0% and specificities of 66.7% vs 64.9% for identifying neonates with TSB ≥256.5 µmol/L. Areas under the receiver operating characteristic curves of parents for identifying TSB ≥119.7, ≥153.9, ≥205.2, and ≥256.5 µmol/L were 0.967, 0.960, 0.915, and 0.813, respectively, and those of paediatricians were 0.966, 0.961, 0.926 and 0.840, respectively. The intraclass correlation coefficient was 0.933 between parents and paediatricians.

CONCLUSION

The JCard can be used to classify different levels of bilirubin, but it is less accurate with high bilirubin levels. The JCard diagnostic performance of parents was slightly lower than that of paediatricians.

Transcutaneous bilirubin level to predict hyperbilirubinemia in preterm neonates

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

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

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

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

[Guidelines for prevention, detection and management of hyperbilirubinaemia in newborns of 35 or more weeks of gestation]

Hyperbilirubinaemia is one of the most frequent causes of hospital readmission during the first week of life. Its detection is still a big challenge, mainly due to the early discharge from the hospital that can be associated with a delay of the diagnosis. The identification of those newborns at risk of developing significant hyperbilirubinaemia is one of the main priorities in the public health care system. An approach to the management of newborn jaundice is presented in this article, following the recommendations based on the medical evidence and on the opinion of the Standards Committee of the Spanish Society of Neonatology.

Parental infant jaundice colour card design successfully validated by comparing it with total serum bilirubin

AIM

We designed a jaundice colour card that could be used by the parents of neonates and validated it by comparing it with total serum bilirubin levels.

METHODS

There were 106 term Chinese neonates in the study. The majority weighed between 2500 g and 3499 g (63%) and had a gestational age of 37-40 weeks (77%). The jaundice colour card and photometric determination were used to screen for neonatal jaundice and compared with serum bilirubin.

RESULTS

The bilirubin levels were measured by mothers using the jaundice colour card, and 67% of the measurements were taken at 11-20 days (range 3-30). The measurements at the infant's forehead, cheek and sternum showed strong correlations with total serum bilirubin. The mean differences between the total serum bilirubin and the jaundice colour card measurements from the forehead, cheek and sternum were 1.9 mg/dL, 0.3 mg/dL and 1.5 mg/dL, respectively. When total serum bilirubin >13 mg/dL was used as the cut-off point, the areas under the receiver operating characteristics curves were 0.934 for the forehead, 0.985 for the cheek and 0.966 for the sternum.

CONCLUSION

We established the validity of the jaundice colour card as a parental measurement tool for jaundice in Chinese neonates, and the cheek was the best measurement site.

Revisiting the Criteria for Exchange Transfusion for Severe Neonatal Hyperbilirubinemia in Resource-Limited Settings

BACKGROUND

Exchange transfusion (ET) for severe neonatal hyperbilirubinemia (SNH) is frequently undertaken in low- and middle-income countries (LMIC), in sharp contrast to the prevailing practice in high-income countries. However, the criteria for initiating this procedure in settings with limited resources for treating infants with SNH have not been systematically explored.

OBJECTIVE

To identify key considerations for initiating ET in resource-poor countries to curtail its unnecessary use for the prevention of kernicterus.

METHODS

A review of the existing guidelines and literature on the management of neonatal hyperbilirubinemia worldwide was conducted to identify criteria and underlying factors for initiating ET.

RESULTS

There is a dearth of evidence from randomized clinical trials to support clear criteria for indicated ET worldwide. Because risk assessment for kernicterus based solely on the levels of total serum bilirubin (TSB) has often proved inadequate, a combination of plasma/serum bilirubin estimation and clinical evaluation for acute bilirubin encephalopathy (ABE) has been recommended for predicting the risk of kernicterus. However, there is a lack of consistency regarding the TSB levels for which ET should be initiated in relation to the clinical signs/symptoms of ABE and hemolytic disorders.

CONCLUSIONS

A decision-making framework that combines TSB thresholds and evidence of neurotoxicity is needed for evaluating the risk of kernicterus and prioritising infants for ET in LMICs to curtail unnecessary interventions.

Management of late-preterm and term infants with hyperbilirubinaemia in resource-constrained settings

Hyperbilirubinaemia is a ubiquitous transitional morbidity in the vast majority of newborns and a leading cause of hospitalisation in the first week of life worldwide. While timely and effective phototherapy and exchange transfusion are well proven treatments for severe neonatal hyperbilirubinaemia, inappropriate or ineffective treatment of hyperbilirubinaemia, at secondary and tertiary hospitals, still prevails in many poorly-resourced countries accounting for a disproportionately high burden of bilirubin-induced mortality and long-term morbidity. As part of the efforts to curtail the widely reported risks of frequent but avoidable bilirubin-induced neurologic dysfunction (acute bilirubin encephalopathy (ABE) and kernicterus) in low and middle-income countries (LMICs) with significant resource constraints, this article presents a practical framework for the management of late-preterm and term infants (≥35 weeks of gestation) with clinically significant hyperbilirubinaemia in these countries particularly where local practice guidelines are lacking. Standard and validated protocols were followed in adapting available evidence-based national guidelines on the management of hyperbilirubinaemia through a collaboration among clinicians and experts on newborn jaundice from different world regions. Tasks and resources required for the comprehensive management of infants with or at risk of severe hyperbilirubinaemia at all levels of healthcare delivery are proposed, covering primary prevention, early detection, diagnosis, monitoring, treatment, and follow-up. Additionally, actionable treatment or referral levels for phototherapy and exchange transfusion are proposed within the context of several confounding factors such as widespread exclusive breastfeeding, infections, blood group incompatibilities and G6PD deficiency, which place infants at high risk of severe hyperbilirubinaemia and bilirubin-induced neurologic dysfunction in LMICs, as well as the limited facilities for clinical investigations and inconsistent functionality of available phototherapy devices. The need to adjust these levels as appropriate depending on the available facilities in each clinical setting and the risk profile of the infant is emphasised with a view to avoiding over-treatment or under-treatment. These recommendations should serve as a valuable reference material for health workers, guide the development of contextually-relevant national guidelines in each LMIC, as well as facilitate effective advocacy and mobilisation of requisite resources for the optimal care of infants with hyperbilirubinaemia at all levels.

An hour-specific transcutaneous bilirubin nomogram for Mongolian neonates

Transcutaneous bilirubin (TcB) nomograms have been developed for different populations. However, the TcB level, rate of rise and peak varies among countries and ethnicities. The aim of this study was to establish an hour-specific TcB nomogram for healthy term and late preterm Mongolian neonates during the first 144 h after birth. A total of 5084 TcB measurements from 1297 healthy neonates (gestational age ≥35 weeks, birth weight ≥2000 g) were obtained from October 2012 to October 2013. All measurements were performed using the Jaundice Meter, the JM-103 at 6 to 144 postnatal hours. Mongolian infants had the following characteristics: 27.1 % were delivered by cesarean section, 17.8 % had a birth weight >4000 g, and >90 % were being breastfed. TcB percentiles for each designated time point were calculated for the development of an hour-specific nomogram. TcB levels increased most rapidly in the first 24 h and less rapidly from 24 to 78 h, reaching a plateau after 78 h for the 50th percentile. TcB levels of Mongolian neonates for each time point were higher than those of previous studies.

CONCLUSION

The higher values of the TcB nomogram for Mongolian neonates may be due to their Asian ethnicity and exclusive breastfeeding.

WHAT IS KNOWN

• TcB nomograms for neonatal jaundice screening have been established for many countries and ethnicities. The pattern of the TcB nomogram varies by country and ethnicity. What is New: • A TcB nomogram for neonates of Mongolian ethnicity at 6-144 postnatal hours was created and it had higher values than those in previous studies.

Validation of a transcutaneous bilirubin meter in Mongolian neonates: comparison with total serum bilirubin

BACKGROUND

Neonatal hyperbilirubinemia, especially kernicterus, can be prevented by screening for neonatal jaundice. The transcutaneous bilirubin (TcB) meter is a non-invasive medical device for screening neonates. The study aimed to investigate the validity of a TcB meter in a resource-limited setting such as Mongolia.

METHODS

Term and late preterm neonates from the National Center for Maternal and Child Health of Ulaanbaatar in Mongolia who met the inclusion criteria (gestational age ≥35 weeks, birth weight ≥2000 g, postnatal age ≤ 1 month) were enrolled in the study. We used a TcB meter, JM-103 to screen for neonatal jaundice. TcB measurements at the infant's forehead and midsternum were performed within 3 h of obtaining samples for total serum bilirubin (TSB) measurement. We analyzed the correlation between TcB measurements and TSB measurements to validate the meter.

RESULTS

A total of 47 term and six late preterm neonates were included in the study. TcB measured by the meter at both the forehead and the midsternum showed a strong correlation with TSB measured in the laboratory. The correlation equations were TSB = 1.409+0.8655 × TcB (R2=0.78871) at the forehead, and TSB = 0.7555+0.8974 × TcB (R2=0.78488) at the midsternum. Bland-Altman plots and the Bradley-Blackwood test showed no significant differences between the two methods at all measured ranges of bilirubin. The mean areas under the curves of TcB at the forehead and midsternum at three TSB levels (>10 mg/dL, >13 mg/dL, >15 mg/dL) of TcB were greater than 0.9, and all had high sensitivity and specificity.

CONCLUSIONS

This study established the validity of the JM-103 meter as a screening tool for neonatal jaundice in term and late preterm infants in Mongolia. Future studies are needed, including the establishment of a TcB hour-specific nomogram, for more effective clinical practice to prevent severe hyperbilirubinemia.

Auditory risk of hyperbilirubinemia in term newborns: a systematic review

OBJECTIVES

High levels of unconjugated bilirubin have been associated with neuronal damage. The auditory brain nuclei and the inferior colliculi are often the first part of the brainstem to be involved, often leading to hearing abnormalities. A systematic review of clinical studies was conducted to evaluate the effect of hyperbilirubinemia on hearing in term newborns, to show the relationship between hearing function and bilirubin levels as well as the effect of treatment.

METHODS

Eligible studies were identified through searches of electronic databases Ovid MEDLINE, Ovid MEDLINE In-Process, Embase, PubMed and The Cochrane Library. Articles obtained were independently reviewed by 2 authors using inclusion criteria to identify eligible studies. The search was restricted to articles written in English, French and Spanish and published between 1970 and 2010. Data extracted included study type, number of patients, bilirubin levels, hyperbilirubinemia criteria, hearing assessment methods, time of hearing assessment and outcome measures.

RESULTS

The nineteen articles included showed heterogeneity regarding the time of hearing test and hyperbilirubinemia criteria. The incidence of hearing loss at initial testing ranged between 13.2-83.3% and 6.7-14.3% at 3 months follow-up. Five studies showed a rising incidence of hearing loss with increasing levels of serum bilirubin.

CONCLUSIONS

Hyperbilirubinemia resulted in abnormal hearing assessment in up to 83.3% of term newborns. Greater hearing abnormalities were observed with rising serum bilirubin levels. Treatment of hyperbilirubinemia led to a considerable decrease in the incidence of hearing loss.

Neonatal hyperbilirubinaemia: time for Italian recommendations?

The introduction of effective therapies for hyperbilirubinemia might have led to a general overconfidence among neonatal healthcare providers. National guidelines have been issued in many countries though they hardly stand the challenge of evidence-based medicine. A comparative appraisal shows significant discrepancies among different documents. As new, compelling evidence sheds a different light on bilirubin toxicity, this heterogeneity that borders confusion should be solved by implementing both clinical and basic research on the complex issue of neonatal hyperbilirubinemia.