Hearing and neurological impairment in children with history of exchange transfusion for neonatal hyperbilirubinemia

Identifying and quantifying initial post-discharge needs for clinical review of sick, newborns in Kenya based on a large multi-site, retrospective cohort study

Background

Progress in neonatal care has resulted in a 51% decrease in global neonatal mortality rates from 1990 to 2017. Enhanced survival will put pressure on health care systems to provide appropriate post-discharge, follow-up care but the scale of need for such care is poorly defined.

Methods

We conducted a retrospective cohort study of newborns discharged from 23 public hospital neonatal units (NBUs) in Kenya between January 2018 and June 2023 to identify initial follow-up needs. We first determined pragmatic follow-up categories based on survivors' clinical conditions and morbidities. We then used individual phenotypes of individual babies to assign them to needing one or more forms of specialized clinical follow-up. We use descriptive statistics to estimate proportions of those with specific needs and patterns of need.

Findings

Among 136,249/159,792 (85.3%) neonates discharged, around one-third (33%) were low birth weight (<2,500 g), and a similar 33.4% were preterm (<37 weeks). We estimated 131,351 initial episodes of follow-up would be needed across nine distinct follow-up categories: general pediatrics, nutrition, growth & development (40.4%), auditory screening (38.8%), ophthalmology for retinopathy of prematurity (9.6%), neurology (8.0%), occupational therapy (1.3%), specialized nutrition (0.9%), surgery (0.8%), cardiology (0.2%), and pulmonary (<0.1%). Most neonates met the criteria for two (52.3%, 28,733), followed by three (39.6%, 21,738) and one follow-up episodes (5.6%, 3,098). In addition to prematurity and very low birth weight (≤1,500 g), severe infections with extended gentamicin treatment, severe jaundice managed with phototherapy, and hypoxic-ischemic encephalopathy (HIE) contributed substantially to the pattern of need for post-discharge follow-up.

Conclusions

Almost half of surviving NBU infants have multiple specialty post-discharge follow-up needs. More urgent attention needs to be focused on healthcare planning now to guide strategies to address the varied medical and developmental needs that we outline in resource-constrained contexts like Kenya.

Developmental outcome of neonates underwent exchange transfusion due to hyperbilirubinemia: A single-center experience

BACKGROUND

Exchange transfusion due to hyperbilirubinemia is performed in neonates with signs of encephalopathy or if the level of bilirubin is more than the exchange threshold and not responding to intensive phototherapy. Bilirubin passage through the blood-brain barrier can cause injury to different sites of the brain and may have long-life effects. In this study, we aimed to evaluate the neonates who underwent exchange transfusion and investigated their developmental problems. By recognizing their developmental delay, we can recommend screening time and early occupational therapy if needed.

METHODS AND MATERIAL

This is a retrospective study on neonates who underwent exchange transfusion due to hyperbilirubinemia in Namazi and Hafez hospitals, in Shiraz, Iran, between 2016 and 2021. The exclusion criteria were the unwillingness of the parents to participate in the study or incomplete data. Children who died were also excluded from the study. Demographic and clinical data were obtained from hospital records. Children were invited to the clinic for examination, and development was assessed by Ages and Stages Questionnaires (ASQ). All neonates had done auditory brainstem response. The result was obtained. Quantitative data are reported as mean standard deviation (SD) and qualitative data with frequency and percentage. Spearman's correlation coefficient and Chi-square test were used, and the P value was significant below 0.05.

RESULTS

Eighty-seven neonates were enrolled. Forty-nine (56.3%) were female, and 38 (43.7%) were male. Glucose-6-phosphate dehydrogenase(G6PD) deficiency was the most prevalent hematologic cause of hyperbilirubinemia (23%). Auditory disorder, speech disorder, motor disorder, and encephalopathy were seen in four (4.6%), two (2.3%), three (3.4%), and four infants (4.6%), respectively.

CONCLUSION

Bilirubin neurotoxicity can cause developmental impairment including auditory, speech, and motor disorders besides encephalopathy. Early recognition and proper early intervention can lead to better outcomes for the child, family, and society.

Short-term outcomes of infants with hyperbilirubinemia-associated auditory neuropathy spectrum disorder in neonatal intensive care unit

OBJECTIVES

Hyperbilirubinemia is a high-risk factor for auditory neuropathy spectrum disorder (ANSD) as well as hearing loss in general. This study described the outcomes of hyperbilirubinemia-associated ANSD infants diagnosed in hearing screening in the neonatal intensive care unit (NICU).

METHODS

A total of 578 children with hyperbilirubinemia admitted to the NICU between October 2020 and October 2021 were included in this study. The distortion product otoacoustic emission (DPOAE) and automatic auditory brainstem response (AABR) were combined for hearing screening, and those who failed the DPOAE or/and AABR underwent an auditory brainstem response (ABR) test. Infants with ANSD were followed up for 12 months.

RESULTS

Forty infants (40/578, 6.9%) failed the DPOAE or/and AABR tests, of which, 13 (13/578, 2.2%) were diagnosed as ANSD, and 27 (27/578, 4.7%) were diagnosed as having sensorineural hearing loss (SNHL). Of the 13 ANSD infants followed up for 12 months, 7 recovered, 3 improved, 3 did not recover, and 1 was lost, equating to improved or recovered hearing in 75% (9/12) of ANSD infants at 12 months of age. Moreover, the maximum bilirubin in recovered or improved ANSD infants was 408.6 ± 129.0 μmol/L, while the maximum bilirubin in unrecovered ANSD infants was 749.3 ± 323.0 μmol/L. Furthermore, poorly differentiated and absent ABR waveforms were observed in 6 and 14 ears at 1 month, 2 ears were lost, 6 (6/6, 100.0%) and 6 (6/12, 50.0%) ears were recovered or improved at 12 months of age.

CONCLUSION

s: The incidence of hyperbilirubinemia associated-ANSD was 2.2% of infants screened in the NICU. ANSD caused by hyperbilirubinemia may be transient, with most infants improving or recovering hearing by 12 months of age. Infants with poorly differentiated ABR waveforms and low bilirubin concentration are more likely to recover and hearing aids are not recommended in hyperbilirubinemia-associated ANSD below 12 months of age.

Analysis of the Risk Factors Associated with Hearing Loss of Infants Admitted to a Neonatal Intensive Care Unit: A 13-Year Experience in a University Hospital in Korea

Early detection of hearing loss in neonates is important for normal language development, especially for infants admitted to the neonatal intensive care unit (NICU) because the infants in NICU have a higher incidence of hearing loss than healthy infants. However, the risk factors of hearing loss in infants admitted to the NICU have not been fully acknowledged, especially in Korea, although they may vary according to the circumstances of each country and hospital. In this study, the risk factors of hearing loss in NICU infants were analyzed by using the newborn hearing screening (NHS) and the diagnostic auditory brainstem response (ABR) test results from a 13-year period. A retrospective chart review was performed using a list of NICU infants who had performed NHS from 2004 to 2017 (n = 2404) in a university hospital in Korea. For the hearing loss group, the hearing threshold was defined as 35 dB nHL or more in the ABR test performed in infants with a 'refer' result in the NHS. A four multiple number of infants who had passed the NHS test and matched the age and gender of the hearing loss group were taken as the control group. Various patient factors and treatment factors were taken as hearing loss related variables and were analyzed and compared. From the 2404 infants involved, the prevalence of hearing loss was 1.8% (n = 43). A comparison between the hearing loss group (n = 43) and the control group (n = 172) revealed that history of sepsis, peak total bilirubin, duration of vancomycin use, days of phototherapy, and exposure to loop-inhibiting diuretics were significantly different, and can be verified as significant risk factors for hearing loss in NICU infants.

Patterns of neurobehavioral functioning in school-aged survivors of neonatal jaundice and hypoxic-ischemic encephalopathy in Kilifi, Kenya: A cross-sectional study

Background: Studies in high-income countries have reported that school-aged children who survive neonatal jaundice (NNJ) and hypoxic-ischemic encephalopathy (HIE) develop long-term neurocognitive problems. However, less is known about the patterns of functioning in school-aged survivors of NNJ and HIE in sub-Saharan Africa. This study examined patterns of functioning in school-aged children who survived NNJ and HIE in Kilifi, Kenya. Methods: This is a cross-sectional study that included 107 survivors of NNJ/HIE (64 with NNJ, 43 with HIE), aged 6-12 years, admitted to Kilifi County Hospital on the Kenyan Coast. The Gross Motor Function Classification System (GMFCS), Adapted Communication Profile, Raven’s Coloured Progressive Matrices (RCPM) and an epilepsy screening tool were used to assess gross motor function, communication function, intellectual functioning, and epilepsy, respectively. Results: Most of the survivors of NNJ (95.2%) and HIE (95.3%) had no impairments in gross motor functioning. A small percentage of the children in the NNJ and HIE groups had profound problems in their communication (4.7% and 4.7%); expressive communication function (4.7% and 4.7%); social functions (3.1% and 2.3%); receptive communication (4.7% and 2.3%); and communicative effectiveness (4.7% and 2.3%). Cognitive impairment was reported in 10.9% and 11.9% for NNJ and HIE survivors, respectively. Active epilepsy was detected in 1.6% of survivors of NNJ and 2.3% of survivors of HIE. All children had normal hearing and visual functioning except one participant who presented with mild visual acuity problems. Conclusions: Most school-aged children who survive with NNJ and HIE have normal motor and communication function; however, one in ten are likely to present with lowered intellectual functioning compared to the normative sample.

Cytomegalovirus-induced pathology in human temporal bones with congenital and acquired infection

OBJECTIVE

Publications on histopathology of human temporal bones with cytomegalovirus (CMV) infection are limited. We aim to determine histopathology of the inner ears and the middle ears in human temporal bones with congenital and acquired CMV infections.

METHODS

Temporal bones from 2 infants with congenital and 2 adults with acquired CMV infection were evaluated by light microscopy.

RESULTS

Two infants with congenital CMV infection showed striking pathological changes in the inner ear. There was a hypervascularization of the stria vascularis in the cochlea of the first infant, but no obvious loss of outer and inner hair cells was seen in the organ of Corti. However, cytomegalic cells and a loss of outer hair cells were found in the cochlea of the second infant. The vestibular organs of both infants showed cytomegalic cells, mostly located on dark cells. There was a loss of type I and type II hair cells in the macula of the saccule and utricle. Loss of hair cells and degeneration of nerve fibers was also seen in the semicircular canals. Both infants with congenital infection showed abundant inflammatory cells and fibrous structures in the middle ear cavity. No evidence of cytomegalic cells and hair cell loss was found in the cochlea or vestibular labyrinth in acquired CMV infection.

CONCLUSIONS

In two infants with congenital CMV infection, the cochlea, vestibule, and middle ear were highly affected. Temporal bones of adult donors with acquired viral infection showed histological findings similar to donors of the same age without ear disease.

Patterns of neurobehavioral functioning in school-aged survivors of neonatal jaundice and hypoxic-ischemic encephalopathy in Kilifi, Kenya: A cross-sectional study

Background: Studies in high-income countries have reported that school-aged children who survive neonatal jaundice (NNJ) and hypoxic-ischemic encephalopathy (HIE) develop long-term neurocognitive problems. However, less is known about the patterns of functioning in school-aged survivors of NNJ and HIE in sub-Saharan Africa. This study examined patterns of functioning in school-aged children who survived NNJ and HIE in Kilifi, Kenya. Methods: This is a cross-sectional study that included 107 survivors of NNJ/HIE (64 with NNJ, 43 with HIE), aged 6-12 years, admitted to Kilifi County Hospital on the Kenyan Coast. The Gross Motor Function Classification System (GMFCS), Adapted Communication Profile, Raven’s Coloured Progressive Matrices (RCPM) and an epilepsy screening tool were used to assess gross motor function, communication function, intellectual functioning, and epilepsy, respectively. Results: Most of the survivors of NNJ (95.2%) and HIE (95.3%) had no impairments in gross motor functioning. A small percentage of the children in the NNJ and HIE groups had profound problems in their communication (4.7% and 4.7%); expressive communication function (4.7% and 4.7%); social functions (3.1% and 2.3%); receptive communication (4.7% and 2.3%); and communicative effectiveness (4.7% and 2.3%). Cognitive impairment was reported in 10.9% and 11.9% for NNJ and HIE survivors, respectively. Active epilepsy was detected in 1.6% of survivors of NNJ and 2.3% of survivors of HIE. All children had normal hearing and visual functioning except one participant who presented with mild visual acuity problems. Conclusions: Most school-aged children who survive with NNJ and HIE have normal motor and communication function; however, one in ten are likely to present with lowered intellectual functioning compared to the normative sample.

Risk Factors for Sensorineural Hearing Loss in Neonatal Hyperbilirubinemia

INTRODUCTION

Hyperbilirubinemia is a common neonatal problem with toxic effects on the nervous system that can cause hearing impairment. This study was conducted to assess the risk factors for sensorineural hearing loss and other coexisting problems in icteric infants.

MATERIALS AND METHODS

In a case-control study, 200 term infants with bilirubin levels higher than 20 mg/dl admitted to the neonatal intensive care unit of Ghaem Hospital, Mashhad during 2007-2015 were investigated. Profiles of infants with hearing impairment (n=60) were compared with those of icteric newborns with normal hearing (140 newborns) as the control group. After confirming the clinical diagnosis of jaundice by laboratory findings, a validated questionnaire containing mother and infant profiles were used for data collection. The auditory brainstem response test was used for assessment of infant hearing status after discharge.

RESULTS

Sensorineural hearing loss among infants with severe hyperbilirubinemia was found to be 4.8%. Serum total bilirubin (P=0.001), creatinine levels (P=0.002), direct Coombs test results (P=0.001), etiology (P=0.000) and treatment for jaundice (P=0.000), eye movement disorders (P=0.001), opisthotonos (P=0.001), and microcephaly (P=0.001) were found to be significantly different between the two groups (P<0.005). The prognostic predictability of sensorineural hearing loss based on total bilirubin level was found to be 82%.

CONCLUSION

Hearing impairment occurs about 10-50 times more frequently in neonates with severe jaundice. Total bilirubin level has the highest predictability for infant hearing status. Blood group and Rhesus (Rh) incompatibilities between mother and child and G6PD deficiency are important known causes for hearing impairment due to jaundice.

Total serum bilirubin levels and sensorineural hearing loss in the US adolescents: NHANES 2007-2010

OBJECTIVE

We aimed to investigate whether current levels of total serum bilirubin are associated with different subtypes of sensorineural hearing loss (SNHL) in adolescents.

METHODS

A set of cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) (2007-2010) was used. A subset of 1404 adolescents was sampled for measurements of total serum bilirubin, tympanometry, and average pure tone threshold at low-frequencies (LPTA: 500, 1000, 2000 Hz) or high-frequencies (HPTA: 3000, 4000, 6000, and 8000 Hz). SNHL was defined as the hearing loss that had type A tympanograms with a peak admittance of 0.3 ml or greater. Associations between serum bilirubin (square-root transformed) and different subtypes of SNHL were evaluated using binary or multinomial logistic regression models with 4-year sampling weights. The bootstrap method was used for estimation of variance and 10-fold cross-validation for assessment of overfitting issue.

RESULTS

Total serum bilirubin levels were found to be associated with any high-frequency (HPTA>15 dB in at least one ear, adjusted odds-ratio (OR_a)(bootstrap 95% confidence interval) = 3.29(1.31-8.19), p = 0.011), but not with any low-frequency (LPTA>15 dB in at least one ear), SNHL in the US adolescents. Furthermore, high-frequency SNHL with HPTA>15 dB in both ears (bilateral) or HPTA≥25 dB in at least one ear, compared to that with HPTA>15 dB in one ear only (unilateral) or HPTA = 15-25 dB in at least one ear, had a stronger association with total serum bilirubin levels (OR_a = 5.37(1.27-22.65), p = 0.022 for bilateral; OR_a = 2.64(0.84-8.25), p = 0.094 for unilateral; OR_a = 5.00(0.95-26.58), p = 0.058 for HPTA≥25 dB in at least one ear; as well as OR_a = 3.06(1.15-8.25), p = 0.025 for HPTA = 15-25 dB in at least one ear). No severe overfitting problems were found.

CONCLUSION

Our findings suggest that current levels of total serum bilirubin may be informative in predicting and/or targeting high-frequency SNHL in the US adolescents.

Bilirubin-Induced Audiologic Injury in Preterm Infants

Although hyperbilirubinemia is extremely common among neonates and is usually mild and transient, it sometimes leads to bilirubin-induced neurologic damage (BIND). The auditory pathway is highly sensitive to the effects of elevated total serum/plasma bilirubin (TB) levels, with damage manifesting clinically as auditory neuropathy spectrum disorder. Compared to full-term neonates, preterm neonates are more susceptible to BIND and suffer adverse effects at lower TB levels with worse long-term outcomes. Furthermore, although standardized guidelines for management of hyperbilirubinemia exist for term and late preterm neonates, similar guidelines for neonates less than 35 weeks gestational age are limited.

Facility-based constraints to exchange transfusions for neonatal hyperbilirubinemia in resource-limited settings

Several clinical guidelines for the management of infants with severe neonatal hyperbilirubinemia recommend immediate exchange transfusion (ET) when the risk or presence of acute bilirubin encephalopathy is established in order to prevent chronic bilirubin encephalopathy or kernicterus. However, the literature is sparse concerning the interval between the time the decision for ET is made and the actual initiation of ET, especially in low- and middle-income countries (LMICs) with significant resource constraints but high rates of ET. This paper explores the various stages and potential delays during this interval in complying with the requirement for immediate ET for the affected infants, based on the available evidence from LMICs. The vital role of intensive phototherapy, efficient laboratory and logistical support, and clinical expertise for ET are highlighted. The challenges in securing informed parental consent, especially on religious grounds, and meeting the financial burden of this emergency procedure to facilitate timely ET are examined. Secondary delays arising from post-treatment bilirubin rebound with intensive phototherapy or ET are also discussed. These potential delays can compromise the effectiveness of ET and should provide additional impetus to curtail avoidable ET in LMICs.

Audiologic impairment associated with bilirubin-induced neurologic damage

Hyperbilirubinemia occurs commonly in neonates and is usually mild and transient, with no long-lasting sequelae. However, bilirubin-induced neurologic damage may occur in some infants. The auditory pathway is the most sensitive part of the central nervous system to bilirubin-induced toxicity, and permanent sequelae may result from only moderately elevated total serum/plasma bilirubin levels. The damage to the auditory system occurs primarily within the brainstem and cranial nerve VIII, and manifests clinically as auditory neuropathy spectrum disorder.

Societal impact of bilirubin-induced hearing impairment in resource-limited nations

Infants with bilirubin-induced neurologic dysfunction (BIND) are characterized by several developmental disabilities including auditory impairments. This paper explores the societal impact of bilirubin-induced auditory impairments, inclusive of hearing impairments and auditory neuropathy spectrum disorders, on these infants, their families, and on the community in resource-limited countries (per capita income of US$6,000 or less). Auditory impairments have substantial emotional, social, and economic impact on the affected infants, their families and communities. The burden is exacerbated by widespread poverty, unfavorable community attitudes towards disabilities, and lack of requisite health, educational, and social services. Curtailing the incidence of avoidable severe hyperbilirubinemia through proactive and effective management of infants at risk or with severe hyperbilirubinemia is necessary at all levels of healthcare delivery. Early detection and intervention for unavoidable auditory impairments should be widely promoted to provide improved developmental trajectories for the affected infants.