Prediction of 3- to 5-Month Outcomes from Signs of Acute Bilirubin Toxicity in Newborn Infants

Unbound Bilirubin and Acute Bilirubin Encephalopathy in Infants Born Late Preterm and Term with Significant Hyperbilirubinemia

OBJECTIVE

To compare the association of unbound bilirubin (UB), total serum bilirubin (TSB), and bilirubin:albumin molar ratio (BAMR) with acute bilirubin encephalopathy (ABE), as assessed by bilirubin-induced neurologic dysfunction (BIND) score, in infants with significant hyperbilirubinemia (TSB ≥20 mg/dL or underwent exchange transfusion).

STUDY DESIGN

In this prospective cohort study, infants ≥34 weeks of gestational age with significant hyperbilirubinemia during the first 2 postnatal weeks were eligible, unless they had craniofacial malformations, chromosomal disorders, TORCH (toxoplasmosis, other infections, rubella, cytomegalovirus and herpes simplex) infections, surgery, or a family history of congenital deafness. TSB, serum albumin, and UB were measured at hospital admission using the colorimetric, bromocresol green, and modified peroxidase method, respectively. Infants were evaluated on admission for ABE using a standardized neurologic examination and assigned a BIND score by trained physicians. Infants with a total BIND score of 0 were deemed to not have ABE, whereas those with a score ≥1 were deemed to have ABE.

RESULTS

A total of 151 infants were studied, among whom 37 (24.5%) had ABE. Of these, 19 had mild ABE (BIND score 1-3) and 18 had moderate-to-severe ABE (BIND score 4-9). On logistic regression, UB, but not TSB or BAMR, was associated with ABE (aOR 1.64; 95% CI 1.17-2.3). On ordered logistic regression, UB, but not TSB or BAMR, was associated with severity of ABE (aOR 1.76; 95% CI 1.28-2.4).

CONCLUSIONS

Our findings of the association between UB and ABE indicate that BIND scoring may be useful for evaluation of ABE in infants ≥34 weeks of gestational age.

Predictive and diagnostic measures for kernicterus spectrum disorder: a prospective cohort study

BACKGROUND

Kernicterus spectrum disorder (KSD) resulting from neonatal hyperbilirubinemia remains a common cause of cerebral palsy worldwide. This 12-month prospective cohort study followed neonates with hyperbilirubinemia to determine which clinical measures best predict KSD.

METHODS

The study enrolled neonates ≥35 weeks gestation with total serum bilirubin (TSB) ≥ 20 mg/dl admitted to Aminu Kano Hospital, Nigeria. Clinical measures included brain MRI, TSB, modified bilirubin-induced neurologic dysfunction (BIND-M), Barry-Albright Dystonia scale (BAD), auditory brainstem response (ABR), and the modified KSD toolkit. MRI signal alteration of the globus pallidus was scored using the Hyperbilirubinemia Imaging Rating Tool (HIRT).

RESULTS

Of 25 neonates enrolled, 13/25 completed 12-month follow-up and six developed KSD. Neonatal BIND-M ≥ 3 was 100% sensitive and 83% specific for KSD. Neonatal ABR was 83% specific and sensitive for KSD. Neonatal HIRT score of 2 was 67% sensitive and 75% specific for KSD; this increased to 100% specificity and sensitivity at 12 months. BAD ≥ 2 was 100% specific for KSD at 3-12 months, with 50-100% sensitivity.

CONCLUSIONS

Neonatal MRIs do not reliably predict KSD. BIND-M is an excellent screening tool for KSD, while the BAD or HIRT score at 3 or 12 months can confirm KSD, allowing for early diagnosis and intervention.

IMPACT

The first prospective study of children with acute bilirubin encephalopathy evaluating brain MRI findings over the first year of life. Neonatal MRI is not a reliable predictor of kernicterus spectrum disorders (KSD). Brain MRI at 3 or 12 months can confirm KSD. The modified BIND scale obtained at admission for neonatal hyperbilirubinemia is a valuable screening tool to assess risk for developing KSD. The Barry Albright Dystonia scale and brain MRI can be used to establish a diagnosis of KSD in at-risk infants as early as 3 months.

Acute bilirubin encephalopathy: Some lessons learned

Acute bilirubin encephalopathy (ABE) is still an insufficiently addressed cause of mortality and long-term morbidity in low- and middle-income countries (LMICs). This article highlights that delayed or incorrect medical advice, inaccurate bilirubin measurements as well as ineffective phototherapy are some of the relevant causes predisposing jaundiced newborns to develop extreme hyperbilirubinemia [EHB, total serum/plasma bilirubin (TB) ≥ 25 mg/dL (428 µmol/L)] and subsequent ABE. Obstacles preventing state of the art management of such infants are also discussed. Prevention of ABE cannot occur without a system-based approach tailored to suit the needs and available resources of each community. Clear set protocols, rigorous training, monitoring, and accurate documentation together with simple innovative affordable technologies that can be locally produced, are essential to observe the change desired.

Can bilirubin/albumin ratio predict neurodevelopmental outcome in severe neonatal hyperbilirubinemia? A 3-month follow up study

Background

The risk of kernicterus and BIND may be in part determined by total serum bilirubin (TSB) and by the level of non-albumin bound free bilirubin, which can easily pass the blood–brain barrier. Free bilirubin (Bf) seems a more reliable predictor for bilirubin neurotoxicity. Bilirubin/albumin ratio (B/A) is considered a surrogate parameter for Bf and has been more useful than TSB. The aim of the study is to determine whether B/A ratio correlates with BIND in newborns with severe hyperbilirubinemia and if it can predict poor neurologic outcome at 3 months follow up.

Results

This prospective study included one hundred seventeen outborn neonates ≥ 35 weeks admitted in a tertiary care neonatal intensive care unit, between May and December 2012, with TSB ≥ 20 mg/dl or necessitating exchange transfusion. Total serum bilirubin and serum albumin were done on admission and bilirubin/albumin ratio was calculated. BIND score was calculated. At the age of 3 months, 112 neonates were followed up with a detailed neurological assessment. Babies who depicted any abnormal motor examination were subjected to brain stem auditory evoked response and MRI examination. Seven infants (6.2%) presented with kernicterus on follow up. BIND scores on admission, mean TSB, and bilirubin/albumin ratio was significantly higher in kernicteric infants compared with those having normal neurological outcome at 3 months of age (P 0.001). The lowest TSB level at which kernicterus occurred in our study was 31 mg/dl. Receiver operation characteristics analysis identified B/A ratio cut off value for predicting kernicterus of 9.6 with sensitivity of 100% and specificity of 91.4%, whereas TSB cut off value of 30 mg/dl showed sensitivity of 100% and specificity of 83%.

Conclusion

B/A ratio is a strong indicator for the risk of kernicterus. B/A is more specific than TSB and should be used in the early management of neonatal hyperbilirubinemia.

Analysis on the MRI and BAEP Results of Neonatal Brain With Different Levels of Bilirubin

BACKGROUND

To explore whether there is abnormality of neonatal brains' MRI and BAEP with different bilirubin levels, and to provide an objective basis for early diagnosis on the bilirubin induced subclinical damage on brains.

METHODS

To retrospectively analyze the clinical data of 103 neonatal patients, to conduct routine brain MRI examination and BAEP testing, and to analyze BAEP and MRI image results of the neonatal patients, who were divided into three groups based on the levels of total serum bilirubin concentration (TSB): 16 cases in mild group (TSB: 0.0-229.0 ěmol/L), 49 cases in moderate group (TSB: 229.0-342.0 ěmol/L), and 38 cases in severe group (TSB ≥ 342.0 ěmol/L).

RESULTS

We found the following: A. Comparison of the bilirubin value of the different group: The bilirubin value of the mild group is 171.99 ± 33.50 ěmol/L, the moderate group is 293.98 ± 32.09 ěmol/L, and the severe group is 375.59 ± 34.25 ěmol/L. The comparison of bilirubin values of the three groups of neonates (p < 0.01) indicates the difference is statistically significant (p < 0.01). B. The weight value of the <2,500 g group is 2.04 ± 0.21 and the ≥2,500 g group is 3.39 ± 0.46; the weight comparison of the two groups indicates that the difference is statistically significant (p < 0.01). C. Comparison of the abnormal MRI of the different groups: The brain MRI result's abnormal ratio of the mild group is 31.25%, the moderate group is 16.33%, and the severe group is 21.05%, but the comparison of brain MRI results of the three neonates groups indicates that the difference is not statistically significant (p > 0.05). D. Comparison of abnormal MRI signal values of globus pallidus on T1WI in different groups: 1. The comparison of normal group signal values with that of mild group (p < 0.05), with that of moderate group, and with that of severe group (p < 0.01) indicates that the difference is statistically significant.

CONCLUSION

At low level of bilirubin, central nervous system damage may also occur and can be detected as abnormality by MRI and BAEP. Meanwhile, MRI and BAEP can also provide early abnormal information for the judgment of central nervous system damage of the children with NHB who have no acute bilirubin encephalopathy (ABE) clinical features, and provide clues for early treatment and early intervention.

Early prediction of adverse outcomes in infants with acute bilirubin encephalopathy

OBJECTIVE

Acute bilirubin encephalopathy (ABE) remains one of the important causes of neonatal mortality and child disability, early identification, and intervention which could improve outcomes. The purpose of this study was to evaluate early predictors of adverse outcomes in infants with ABE.

METHODS

Newborns of gestational age ≥ 35 weeks and diagnosed with ABE were included in the study. Bilirubin-induced neurological dysfunction (BIND) score, total serum bilirubin (TSB) peak value, and serum albumin levels were determined. Adverse outcomes were defined as death or survival with auditory dysfunction and/or cerebral palsy.

RESULTS

Eighty-two infants were eligible for recruitment in the study. The outcome data from 76 ABE infants (92%) were used for analysis, of which 25 infants got adverse outcomes and 51 live a normal life. Univariate analysis for BIND score, TSB peak value, bilirubin-albumin ratio (B/A), albumin level, abnormal AABR, and neonatal sepsis was performed to elucidate the association with adverse outcomes. Bivariate logistic regression analysis showed B/A (OR 10.48, 95%CI: 1.55-70.81, P = 0.02) and BIND score (OR 3.68, 95%CI: 1.39-9.72, P = 0.01) were correlated with adverse outcomes. ROC curve analysis showed that B/A (≥8.9 mg/g), BIND score (≥6) could predict adverse outcomes of ABE separately; B/A in conjunction with BIND score could increase prediction sensitivity to 100%.

INTERPRETATION

Both B/A and BIND score can be used to predict adverse outcomes of ABE, and the combination of the two parameters can increase prediction sensitivity significantly.

Maternal Instruction About Jaundice and the Incidence of Acute Bilirubin Encephalopathy in Nigeria

OBJECTIVE

To evaluate whether teaching mothers about neonatal jaundice will decrease the incidence of acute bilirubin encephalopathy among infants admitted for jaundice.

STUDY DESIGN

This was a multicenter, before-after and cross-sectional study. Baseline incidences of encephalopathy were obtained at 4 collaborating medical centers between January 2014 and May 2015 (Phase 1). Structured jaundice instruction was then offered (May to November 2015; Phase 2) in antenatal clinics and postpartum. Descriptive statistics and logistic regression models compared 3 groups: 843 Phase 1 controls, 338 Phase 2 infants whose mothers received both antenatal and postnatal instruction (group A), and 215 Phase 2 infants whose mothers received no instruction (group B) either because the program was not offered to them or by choice.

RESULTS

Acute bilirubin encephalopathy occurred in 147 of 843 (17%) Phase 1 and 85 of 659 (13%) Phase 2 admissions, which included 63 of 215 (29%) group B and 5 of 338 (1.5%) group A infants. OR for having acute bilirubin encephalopathy, comparing group A and group B infants adjusted for confounding risk factors, was 0.12 (95% CI 0.03-0.60). Delayed care-seeking (defined as an admission total bilirubin ≥18 mg/dL at age ≥48 hours) was the strongest single predictor of acute bilirubin encephalopathy (OR 11.4; 6.6-19.5). Instruction decreased delay from 49% to 17%. Other major risk factors were home births (OR 2.67; 1.69-4.22) and hemolytic disease (hematocrit ≤35% plus bilirubin ≥20 mg/dL) (OR 3.03; 1.77-5.18). The greater rate of acute bilirubin encephalopathy with home vs hospital birth disappeared if mothers received jaundice instruction.

CONCLUSIONS

Providing information about jaundice to mothers was associated with a reduction in the incidence of bilirubin encephalopathy per hospital admission.

Extreme neonatal hyperbilirubinemia and kernicterus spectrum disorder in Denmark during the years 2000-2015

OBJECTIVE

To determine the incidence and etiology of extreme neonatal hyperbilirubinemia, defined as total serum bilirubin (TSB) ≥450 µmol/L, and kernicterus spectrum disorder (KSD) in Denmark between 2000 and 2015.

STUDY DESIGN

We identified all infants born between 01.01.2000 and 31.12.2015 with TSB ≥450 µmol/L, ratio of conjugated to TSB <0.30, gestational age ≥35 weeks, and postnatal age ≤4 weeks, using Danish hospitals' laboratory databases.

RESULT

We included 408 infants. The incidence of extreme neonatal hyperbilirubinemia among infants with gestational age ≥35 weeks was 42/100,000 during the study period with a seemingly decreasing incidence between 2005 and 2015. Twelve of the 408 infants developed KSD, (incidence 1.2/100,000) Blood type ABO isohemolytic disease was the most common explanatory etiology.

CONCLUSIONS

Our study stresses the importance of a systematic approach to neonatal jaundice and ongoing surveillance of extreme neonatal hyperbilirubinemia and KSD.

The spectrum of bilirubin neurotoxicity in term and near-term babies with hyperbilirubinemia: Does outcome improve with time?

BACKGROUND

While neonatal jaundice is generally a common benign condition; severe hyperbilirubinemia has a devastating potential for brain injury.

AIM

To detect the impact of severe neonatal hyperbilirubinemia on motor and mental development and its progress over time in the first year of life using the Bayley scales of infant development (BSID) II.

STUDY DESIGN AND PATIENTS

177 term/near-term infants admitted for neonatal hyperbilirubinemia to the NICU of Cairo University Children's Hospital were enrolled. Clinical examination, BIND score and laboratory tests were performed at admission. Neurodevelopmental assessment using BSIDΙΙ was performed at 3 months for 147/177 neonates, and at 6 months and 12 months for 139/177 neonates. Auditory brainstem evoked potential was recorded at 3 months of age and repeated if abnormal.

OUTCOME MEASURES

Psychomotor (PDI) and mental developmental indices (MDI) using BSIDII. Auditory impairment using Auditory Brainstem Response (ABR).

RESULTS

TSB levels ranged from 10 to 63 mg/dL (179.6-1077 μmol/L) with a mean of 25.52 ± 6.5 mg/dL (436 ± 112.9 μmol/L) and BIND scores ranged from 0 to 7. By one year of age, 19/139 patients were affected; 8 had classic kernicterus, 3 had isolated auditory impairment, 1 had severe motor and mild mental delay and 7 had mild motor delay. TSB level and BIND score had positive correlation with auditory impairment and lower scores for PDI (which improved with time) and MDI (which remained stationary). Duration of exposure to hyperbilirubinemia negatively affected neurodevelopmental scores.

CONCLUSION

The impact of severe hyperbilirubinemia is mainly on motor and auditory impairment. Mild mental delay was detected by BSIDII in few patients. Neurodevelopmental outcome improves over time.

Clinicopathological Spectrum of Bilirubin Encephalopathy/Kernicterus

Bilirubin encephalopathy/kernicterus is relatively rare, but continues to occur despite universal newborn screening. What is more interesting is the spectrum of clinical and even neuropathological findings that have been reported in the literature to be associated with bilirubin encephalopathy and kernicterus. In this review, the authors discuss the array of clinicopathological findings reported in the context of bilirubin encephalopathy and kernicterus, as well as the types of diagnostic testing used in patients suspected of having bilirubin encephalopathy or kernicterus. The authors aim to raise the awareness of these features among both pediatric neurologists and neuropathologists.

Emergency release uncross-matched packed red blood cells for immediate double volume exchange transfusion in neonates with intermediate to advanced acute bilirubin encephalopathy: timely but insufficient?

Given the urgency of double volume exchange transfusion (ExT) in an infant with intermediate to advanced stages of acute bilirubin encephalopathy (ABE), it has been suggested that emergency release uncross-matched packed red blood cells (ER-PRBC) be used. The efficacy of an ExT in removing bilirubin from the brain, however, is a direct function of the mass of albumin exchanged. The very low albumin content of ER-PRBC may fail to be neuroprotective. Predicted changes in total serum bilirubin (TSB), serum albumin, the bilirubin/albumin (B/A) ratio, plasma volume (PV), and bilirubin equilibration from the extravascular space during ER-PRBC ExT are described. ExT using ER-PRBC is efficacious in lowering the TSB. However, this result is falsely reassuring as significant concurrent serum albumin loss, resultant hypoalbuminemia, contraction of PV, limited bilirubin clearance from the extravascular space, and sustained B/A ratio elevations above recommended ExT treatment thresholds suggest that bilirubin neurotoxicity will continue.

Patterns of acute bilirubin encephalopathy in Nigeria: a multicenter pre-intervention study

BACKGROUND

Acute bilirubin encephalopathy (ABE) is an important cause of neonatal morbidity in Nigeria, accounting for 5-14% of neonatal deaths. Most newborns with severe ABE have irreversible damage before receiving treatment emphasizing the need for timely pre-admission monitoring and referral. There is limited evidence that educational interventions targeting mothers and health care providers will reduce delayed care.

OBJECTIVE

To provide baseline data on the incidence of ABE and associated pre-admission risk factors in five centers of Nigeria in order to evaluate the effect of subsequent educational interventions on outcome.

STUDY DESIGN

The incidence of ABE among newborns treated for hyperbilirubinemia was documented prospectively. Bivariate analysis and multivariate logistic regression were used to evaluate risk factors for acute bilirubin encephalopathy and reasons for regional differences in its occurrence.

RESULTS

Of 1040 infants, 159 treated for hyperbilirubinemia (15.3%) had mild to severe bilirubin encephalopathy (including 35 deaths), but the incidence ranged from 7 to 22% between centers. Logistic regression identified four common predictors: total serum bilirubin (odds ratio 1.007 per mg/dl rise), out-of-hospital births (OR 2.6), non-alloimmune hemolytic anemia (OR 2.8), and delayed care seeking (OR 4.3).

CONCLUSION

The high occurrence of bilirubin encephalopathy in Nigeria is due in large part to a delay in seeking care. A planned intervention strategy will target conditions leading to severe hyperbilirubinemia and delay.