The hypoxic ischaemic encephalopathy score in predicting neurodevelopmental outcomes among infants with birth asphyxia at the Muhimbili National Hospital, Dar-es-Salaam, Tanzania

Prevalence of hearing impairment in neonatal encephalopathy due to hypoxia-ischemia: a systematic review and meta-analysis

BACKGROUND

This systematic review was undertaken to estimate the overall prevalence of hearing impairment in survivors of neonatal HIE.

METHODS

PubMed, EMBASE, CINAHL, EMCARE and Cochrane databases, mednar (gray literature) were searched till January 2023. Randomized controlled trials and observational studies were included. The main outcome was estimation of overall prevalence of hearing impairment in survivors of HIE.

RESULTS

A total of 71studies (5821 infants assessed for hearing impairment) were included of which 56 were from high income countries (HIC) and 15 from low- or middle-income countries (LMIC). Overall prevalence rate of hearing impairment in cooled infants was 5% (95% CI: 3-6%, n = 4868) and 3% (95% CI: 1-6%, n = 953) in non-cooled HIE infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%).

CONCLUSIONS

These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE. There is a need for more data from LMICs and standardization of reporting hearing impairment.

IMPACT

The overall prevalence rate of hearing impairment in cooled infants with HIE was 5% (95% CI: 3-6%) and 3% (95% CI: 1-6%) in the non-cooled infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%). These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE.

Predictive Models of Neurodevelopmental Outcomes After Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVES

To develop predictive models for death or neurodevelopmental impairment (NDI) after neonatal hypoxic-ischemic encephalopathy (HIE) from data readily available at the time of NICU admission ("early") or discharge ("cumulative").

METHODS

In this retrospective cohort analysis, we used data from the Children's Hospitals Neonatal Consortium Database (2010-2016). Infants born at ≥35 weeks' gestation and treated with therapeutic hypothermia for HIE at 11 participating sites were included; infants without Bayley Scales of Infant Development scores documented after 11 months of age were excluded. The primary outcome was death or NDI. Multivariable models were generated with 80% of the cohort; validation was performed in the remaining 20%.

RESULTS

The primary outcome occurred in 242 of 486 infants; 180 died and 62 infants surviving to follow-up had NDI. HIE severity, epinephrine administration in the delivery room, and respiratory support and fraction of inspired oxygen of 0.21 at admission were significant in the early model. Severity of EEG findings was combined with HIE severity for the cumulative model, and additional significant variables included the use of steroids for blood pressure management and significant brain injury on MRI. Discovery models revealed areas under the curve of 0.852 for the early model and of 0.861 for the cumulative model, and both models performed well in the validation cohort (goodness-of-fit χ²: P = .24 and .06, respectively).

CONCLUSIONS

Establishing reliable predictive models will enable clinicians to more accurately evaluate HIE severity and may allow for more targeted early therapies for those at highest risk of death or NDI.

Correlation Between Heart Rate Characteristic Index Score and Severity of Brain Injury in Neonates With Hypoxic-Ischemic Encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) remains devastating for neonates despite widespread treatment with therapeutic hypothermia (TH). The heart rate characteristic (HRC) index score, a measure of heart rate variability, could prove useful in the management of neonates with HIE as new therapies emerge or when withdrawal-of-support decisions are being considered.

PURPOSE

The main purpose was to describe correlation between HRC index scores and brain magnetic resonance imaging (MRI) severity of injury for neonates with HIE.

METHODS/ANALYSIS

Low/high HRC index scores retrieved at initiation of TH (baseline), 24, 48, 72, and 96 hours, brain MRI severity of injury, and National Institute of Child Health and Human Development Death/Disability and Death scores were collected and analyzed retrospectively. Independent t tests and linear regression were used to examine relationships for each outcome measure.

RESULTS

Twenty-seven neonates were stratified into 2 groups: noninjury (n = 11) and injury (n = 16). Statistically significant relationships were observed. Strikingly, mean low HRC index score for the noninjury group ranged between 0.37 and 0.65 and was between 0.61 and 0.86 for the injury group. Mean high HRC index score for the noninjury group ranged between 0.66 and 1.02 and was between 1.04 and 1.41 for the injury group.

IMPLICATIONS FOR PRACTICE

HRC index score may be a useful guide in the future management of neonates with HIE.

IMPLICATIONS FOR RESEARCH

This study established correlations between HRC index and MRI injury scores in neonates treated with TH. Further research is warranted to establish important relationships between brain injury and HRC index scores before this tool can be used clinically for this purpose.

The Thompson Encephalopathy Score and Short-Term Outcomes in Asphyxiated Newborns Treated With Therapeutic Hypothermia

BACKGROUND

The Thompson encephalopathy score is a clinical score to assess newborns suffering from perinatal asphyxia. Previous studies revealed a high sensitivity and specificity of the Thompson encephalopathy score for adverse outcomes (death or severe disability). Because the Thompson encephalopathy score was developed before the use of therapeutic hypothermia, its value was reassessed.

OBJECTIVE

The purpose of this study was to assess the association of the Thompson encephalopathy score with adverse short-term outcomes, defined as death before discharge, development of severe epilepsy, or the presence of multiple organ failure in asphyxiated newborns undergoing therapeutic hypothermia.

METHODS

The study period ranged from November 2010 to October 2014. A total of 12 tertiary neonatal intensive care units participated. Demographic and clinical data were collected from the "PharmaCool" multicenter study, an observational cohort study analyzing pharmacokinetics of medication during therapeutic hypothermia. With multiple logistic regression analyses the association of the Thompson encephalopathy scores with outcomes was studied.

RESULTS

Data of 142 newborns were analyzed (male: 86; female: 56). Median Thompson score was 9 (interquartile range: 8 to 12). Median gestational age was 40 weeks (interquartile range 38 to 41), mean birth weight was 3362 grams (standard deviation: 605). All newborns manifested perinatal asphyxia and underwent therapeutic hypothermia. Death before discharge occurred in 23.9% and severe epilepsy in 21.1% of the cases. In total, 59.2% of the patients had multiple organ failure. The Thompson encephalopathy score was not associated with multiple organ failure, but a Thompson encephalopathy score ≥12 was associated with death before discharge (odds ratio: 3.9; confidence interval: 1.3 to 11.2) and with development of severe epilepsy (odds ratio: 8.4; confidence interval: 2.5 to 27.8).

CONCLUSION

The Thompson encephalopathy score is a useful clinical tool, even in cooled asphyxiated newborns. A score ≥12 is associated with adverse outcomes (death before discharge and development of severe epilepsy). The Thompson encephalopathy score is not associated with the development of multiple organ failure.

Long-term neurodevelopmental outcome in high-risk newborns in resource-limited settings: a systematic review of the literature

BACKGROUND

Improving outcomes beyond survival for high-risk newborns in resource-limited settings is an emerging challenge. Global estimates demonstrate the scale of this challenge and significant gaps in morbidity outcome data in high mortality contexts. A systematic review was conducted to document the prevalence of neurodevelopmental impairment in high-risk newborns who were followed up into childhood in low- and middle-income countries.

METHODS

High-risk newborns were defined as low, very or extremely low birthweight, preterm infants or those surviving birth asphyxia or serious infections. Electronic databases were searched and articles screened for eligibility. Included articles were appraised according to STROBE criteria. Narrative review was performed and median prevalence of key neurodevelopmental outcomes was calculated where data quality allowed.

RESULTS

6959 articles were identified with sixty included in final review. At follow-up in early childhood, median estimated prevalence (inter-quartile range) of overall neurodevelopmental impairment, cognitive impairment and cerebral palsy were: for survivors of prematurity/very low birthweight 21.4% (11.6-30.8), 16.3% (6.3-29.6) and 11.2% (5.9-16.1), respectively, and for survivors of birth asphyxia 34.6% (25.4-51.5), 11.3% (7.7-11.8) and 22.8% (15.7-31.4), respectively. Only three studies reporting outcomes following newborn serious bacterial infections were identified. There was limited reporting of important outcomes such as vision and hearing impairment. Major challenges with standardised reporting of key exposure and developmental outcome variables and lack of control data were identified.

CONCLUSION

Understanding the limitations of the available data on neurodevelopmental outcome in newborns in resource-limited settings provides clear direction for research and efforts to improve long-term outcome in high-risk newborns in these settings.

Intrapartum-related neonatal encephalopathy incidence and impairment at regional and global levels for 2010 with trends from 1990

BACKGROUND

Intrapartum hypoxic events ("birth asphyxia") may result in stillbirth, neonatal or postneonatal mortality, and impairment. Systematic morbidity estimates for the burden of impairment outcomes are currently limited. Neonatal encephalopathy (NE) following an intrapartum hypoxic event is a strong predictor of long-term impairment.

METHODS

Linear regression modeling was conducted on data identified through systematic reviews to estimate NE incidence and time trends for 184 countries. Meta-analyses were undertaken to estimate the risk of NE by sex of the newborn, neonatal case fatality rate, and impairment risk. A compartmental model estimated postneonatal survivors of NE, depending on access to care, and then the proportion of survivors with impairment. Separate modeling for the Global Burden of Disease 2010 (GBD2010) study estimated disability adjusted life years (DALYs), years of life with disability (YLDs), and years of life lost (YLLs) attributed to intrapartum-related events.

RESULTS

In 2010, 1.15 million babies (uncertainty range: 0.89-1.60 million; 8.5 cases per 1,000 live births) were estimated to have developed NE associated with intrapartum events, with 96% born in low- and middle-income countries, as compared with 1.60 million in 1990 (11.7 cases per 1,000 live births). An estimated 287,000 (181,000-440,000) neonates with NE died in 2010; 233,000 (163,000-342,000) survived with moderate or severe neurodevelopmental impairment; and 181,000 (82,000-319,000) had mild impairment. In GBD2010, intrapartum-related conditions comprised 50.2 million DALYs (2.4% of total) and 6.1 million YLDs.

CONCLUSION

Intrapartum-related conditions are a large global burden, mostly due to high mortality in low-income countries. Universal coverage of obstetric care and neonatal resuscitation would prevent most of these deaths and disabilities. Rates of impairment are highest in middle-income countries where neonatal intensive care was more recently introduced, but quality may be poor. In settings without neonatal intensive care, the impairment rate is low due to high mortality, which is relevant for the scale-up of basic neonatal resuscitation.