Whole-body hypothermia for neonates with hypoxic-ischemic encephalopathy

Dexmedetomidine Improves Long-term Neurological Outcomes by Promoting Oligodendrocyte Genesis and Myelination in Neonatal Rats Following Hypoxic-ischemic Brain Injury

Neonatal hypoxic-ischemic brain injury (HIBI) can lead to white matter damage, which significantly contributes to cognitive dysfunction, emotional disorders, and sensorimotor impairments. Although dexmedetomidine enhances neurobehavioral outcomes, its impact on oligodendrocyte genesis and myelination following hypoxic-ischemic events, as well as the underlying mechanisms, remain poorly understood. Dexmedetomidine was administered 15 min post-HIBI. We assessed neurobehavioral deficits using various tests: surface righting, negative geotaxis, forelimb grip strength, cliff avoidance, sensory reflexes, novel object recognition, T-maze, and three-chamber social interaction. We also investigated the relationship between myelination and neurobehavioral outcomes. Measurements included oligodendrocyte precursor cell (OPC) proliferation and survival 24 h post-injury, early myelination, and oligodendrocyte differentiation by postnatal day 14. Furthermore, we evaluated microglial activation towards the M2 phenotype and the extent of neuroinflammation during the acute phase. Dexmedetomidine significantly ameliorated long-term neurological deficits caused by HIBI. Pearson linear regression analysis revealed a strong correlation between long-term neurological outcomes and myelin maturity. The treatment notably mitigated the long-term deterioration of myelin formation and maturation following HIBI. This protective effect was primarily due to enhanced OPC proliferation and survival post-HIBI during the acute phase and, to a lesser extent, to the modulation of microglial activity towards the M2 phenotype and a reduction in neuroinflammation. Dexmedetomidine offers substantial protection against long-term neurobehavioral disabilities induced by HIBI, primarily by revitalizing the impaired survival and maturation of oligodendrocyte progenitor cells and promoting myelination.

Whole-Body Hypothermia for Neonatal Encephalopathy in Preterm Infants 33 to 35 Weeks' Gestation: A Randomized Clinical Trial

Importance

Hypothermia begun less than 6 hours after birth reduces death or disability in infants with encephalopathy due to hypoxia-ischemia at 36 or more weeks' gestation. Trials of hypothermia for infants younger than 36 weeks' gestation are lacking.

Objective

To assess the probability that hypothermia at less than 6 hours after birth decreases death or disability in infants 33 to 35 weeks' gestation with moderate or severe hypoxic-ischemic encephalopathy.

Design, Setting, and Participants

This randomized clinical trial was conducted between July 2015 and December 2022 for infants 33 to 35 weeks' gestation with moderate or severe hypoxic-ischemic encephalopathy at less than 6 hours after birth. Bayesian and intention-to-treat analyses were prespecified. The setting included 19 US Neonatal Research Network centers. Data were analyzed from March 2023 to November 2024.

Interventions

Infants received unblinded targeted esophageal temperature management. Infants with hypothermia were maintained at 33.5 °C (acceptable 33-34 °C) for 72 hours and then rewarmed. Infants with normothermia were to be maintained at 37 °C (acceptable 36.5-37.3 °C).

Main Outcomes and Measures

Composite of death or disability (moderate or severe) at 18 to 22 months' corrected age adjusted for level of encephalopathy and center.

Results

A total of 168 infants with hypothermia and normothermia were preterm (mean [SD] age, 34.0 [0.8] weeks' gestation and 34.1 [0.8] weeks' gestation, respectively), while 46 of 88 (52%) and 45 of 80 (56%) were male, respectively. Randomization occurred at mean (SD) 4.5 (1.2) hours and 4.5 (1.3) hours for the groups with hypothermia and normothermia, respectively. The primary outcome occurred in 29 of 83 infants (35%) with hypothermia and 20 of 69 infants (29%) with normothermia (adjusted relative risk [hypothermic/normothermic], 1.11; 95% credibility interval, 0.74-2.00), and death occurred in 18 of 88 infants (20%) with hypothermia and 9 of 78 infants (12%) with normothermia (adjusted relative risk, 1.38; 95% credibility interval, 0.79-2.85). Bayesian analysis with neutral prior indicated 74% probability of increased death or disability and 87% probability of increased death with hypothermia.

Conclusions and Relevance

Among infants 33 to 35 weeks' gestation with hypoxic-ischemic encephalopathy, hypothermia at less than 6 hours' age did not reduce death or disability at 18 to 22 months' corrected age.

Trial Registration

ClinicalTrials.gov Identifier: NCT01793129.

Opening of the Mitochondrial Permeability Transition Pore Mediated Myocardial Damage After Perinatal Asphyxia in Neonatal Rats

OBJECTIVES

This study investigated the mechanisms underlying myocardial damage after perinatal hypoxia.

METHODS

An intrauterine hypoxia-ischemia model (I/U HI) and a hypoxia/reoxygenation (H/R) model were established. Myocardial damage, mitochondrial function, and mitochondria permeability transition pore (MPTP) opening were determined. The results, presented as means ± SD, were analyzed using SPSS.

RESULTS

Intrauterine hypoxia induced cardiac damage, mitochondrial dysfunction, and MPTP opening in neonatal rats. H/R led to apoptosis and MPTP opening. cTnI and apoptosis-inducing factor (AIF) levels were positively correlated with the degree of MPTP opening. The larger degree of MPTP opening combined with the significant increases in the Ca2+, ROS, and decreases in mitochondrial membrane potential and ATP levels. The larger degree of MPTP opening combined with the stronger release of cytochrome c and AIF.

CONCLUSIONS

Increased MPTP opening may play a crucial role in perinatal asphyxia-induced myocardial damage in neonatal rats.

Prediction of 18 to 22 Month Neurodevelopmental Outcomes Using the Numerical Sarnat Score Compared with Modified Sarnat Staging in Infants with Moderate to Severe Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To examine the association of a numerical Sarnat score (NSS) and modified Sarnat staging among newborn infants with moderate/severe hypoxic-ischemic encephalopathy and their neurodevelopmental outcomes at 18 to 22 months.

STUDY DESIGN

This secondary analysis included participants with gestational age ≥36 weeks and moderate/severe HIE from the Induced Hypothermia (IH) and Optimizing Cooling (OC) trials. Early (<6 hours age) neurologic examinations were performed by trained examiners to categorize HIE severity by modified Sarnat staging. The NSS was calculated by summing abnormal scores (2 for moderate, 3 for severe) in the six examination categories. The primary outcome was death or moderate/severe disability. Statistical analysis included logistic regression, adjusting for center, trial, and cooling group, and linear regression for continuous scales.

RESULTS

The cohort (n=528) included infants with 71% moderate and 29% severe HIE (37% IH and 63% OC participants). Median (IQR) NSS of infants with moderate and severe HIE were 11 (9-13) and 16 (16-17), respectively. There were significant associations between NSS, NSS tertiles, and modified Sarnat staging and death or disability, but there were no differences found in their area-under-the-curve estimates. Similar to modified Sarnat staging, NSS showed significant associations with Bayley-III cognitive, language, and motor scores and Bayley-II mental and psychomotor developmental indices.

CONCLUSION

Among infants with moderate or severe HIE, the NSS did not improve the predictive accuracy for death or disability at 18 to 22 months of age, compared with modified Sarnat staging performed in the initial 6 hours after birth by trained examiners.

Sedation and Pain Management in Neonates Undergoing Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a common cause of significant neonatal morbidity and mortality. The stronghold of the treatment for moderate-to-severe HIE is therapeutic hypothermia (TH) which provides a neuroprotective effect. However, it also is associated with pain and stress. Moreover, neonates with HIE are subjected to a significant number of painful procedures. Untreated pain during the early neonatal period may entail future challenges such as impaired brain growth and development as well as impaired pain sensitivity later in life. Hereby, the provision of adequate sedation and alleviation of pain and discomfort is essential. There are currently no universally accepted guidelines for sedation and pain management for this patient population. In this review, we highlight non-pharmacologic and pharmacologic methods currently in use to provide comfort and sedation to patients with HIE undergoing TH.

NICHD Magnetic Resonance Brain Imaging Score in Term Infants With Hypoxic-Ischemic Encephalopathy: A Secondary Analysis of a Randomized Clinical Trial

Importance

The neonatal brain injury score on magnetic resonance imaging following moderate or severe hypoxic-ischemic encephalopathy developed by the National Institute of Child Health and Human Development Neonatal Research Network has been revised to separate watershed and basal ganglia or thalamic injury and their associated outcomes.

Objective

To evaluate the association of the injury score with outcomes of death or moderate or severe disability among all infants, and with neurodevelopment among survivors in a trial of deeper and longer cooling.

Design, Setting, and Participants

In this secondary analysis of a multicenter randomized clinical trial, brain imaging was obtained from infants between October 2010 and November 2013. Infants were followed up to 18 months of age, with follow-up completed in January 2016. Data analysis was performed from August 2021 to September 2024.

Interventions

Infants were assigned to 4 hypothermia groups based on depth and duration of cooling, stratified by center and level of encephalopathy in a 2 × 2 factorial design to cooling at 33.5 °C or 32.0 °C and to 72 or 120 hours. A 10-level brain injury score was examined.

Main Outcomes and Measures

The primary outcome was death or moderate or severe disability measured by the Bayley Scales of Infant and Toddler Development III, the Gross Motor Function Classification System level, vision, and hearing.

Results

This study included 298 infants who had magnetic resonance imaging (MRI) and primary outcome data among 364 infants of the initial cohort (mean [SD] age at MRI, 9.18 [4.49] days). Death or moderate or severe disability occurred in 72 of 298 infants (24%), and disability occurred in 52 of 278 surviving infants (19%). Death or disability occurred in 12 of 28 infants (43%) with any or predominant watershed injury and in 17 of 46 (37%) of those with any or predominant basal ganglia or thalamic injury. Among the 32 infants with hemispheric devastation, 30 (94%) had death or disability, and 17 (89%) survived with moderate or severe disability. Injury scores of increasing severity were associated with death or disability among all infants (odds ratio, 13.66 [95% CI, 7.47-24.95]; area under the curve, 0.84 [95% CI, 0.78-0.90]) and with disability among surviving infants (odds ratio, 10.52 [95% CI, 5.46-20.28]; area under the curve, 0.80 [95% CI, 0.73-0.88]). There were no differences in the injury score between infants undergoing usual care cooling and those cooled to a greater depth or longer duration.

Conclusions

Among infants with hypoxic-ischemic encephalopathy, outcomes were similar between infants with watershed and basal ganglia injury. Higher imaging scores were associated with risk of death or disability among all infants and with neurodevelopmental disability among surviving infants.

Trial Registration

ClinicalTrials.gov Identifier: NCT01192776.

Population Pharmacokinetics of Caffeine in Infants with Hypoxic-Ischemic Encephalopathy: A Phase I, Dose-Escalating Trial

The mainstay of treatment for infants with hypoxic-ischemic encephalopathy (HIE) is cooling. Caffeine may be an important adjunct to cooling and provide neuroprotection via its anti-inflammatory and anti-oxidative properties. This study aimed to characterize caffeine pharmacokinetics in term infants with HIE receiving cooling. In this phase 1, dose-escalating study, enrolled infants received IV caffeine 20 mg/kg followed by up to two daily doses of 5 or 10 mg/kg. A population pharmacokinetic analysis was performed using NONMEM (v7.5). The effects of clinical covariates, including cooling, on pharmacokinetic parameters were evaluated. Dosing simulations were performed to evaluate the percentage of plasma exposures in the reference range (15-25 mg/L). Seventeen infants were included in model development. A one-compartment model best fit the data. Population clearance was 0.445 L/h/70 kg and volume of distribution was 87.1 L/70 kg. Current dosing regimens (20 mg/kg followed by 5 mg/kg) resulted in 89.5% of infants having at least one simulated exposure below the reference range across the dosing interval. Dosing regimens of 30 mg/kg followed by 5 or 10 mg/kg were predicted to result in more than half of infants achieving simulated exposures in the reference range, with ≤20% of infants having simulated exposures in the toxic range (>46 mg/L). Term infants with HIE had similar weight-normalized clearance but higher weight-normalized volume of distribution compared to prior studies in preterm infants without HIE or cooling. While exposure targets for neuroprotection in HIE are unknown, this phase 1 study suggests alternate dosing strategies should be considered in future studies.

Motor activities and executive functions in early adolescence after hypothermia-treated neonatal hypoxic-ischemic encephalopathy

AIM

To explore the relationship between motor activities and executive functions (EF) in children (aged 10-12 years) with a history of neonatal hypothermia-treated hypoxic-ischemic encephalopathy (HIE).

MATERIAL AND METHODS

Forty-five children (mean age 11 years) with a history of neonatal hypothermia-treated HIE in Stockholm (2007-2009) were included in this cross-sectional study. The children were assessed with Movement Assessment Battery for Children-2 (MABC-2) and Wechsler Intelligence Scale for Children-V (WISC-V). Their parents completed Behavior Rating Inventory of Executive Function-2 (BRIEF-2), Five to Fifteen-R, and MABC-2 Checklist.

RESULTS

Associations between motor capacity and EF, specifically Processing Speed, Working Memory, Flexibility, and Inhibition, were detected. Children scoring below the 15th percentile on MABC-2 had weaker EF, evident in Cognitive Proficiency Index from WISC-V (t43 = 2.515, p = 0.016) and a higher mean Global Executive Composition Score from BRIEF-2 (t43 = -2.890, p = 0.006). Children with stronger EF exhibited better motor capacity. Parental questionnaires indicated everyday difficulties in 52% of the children.

CONCLUSIONS

Weaker EF were associated with difficulties in motor activities in early adolescence following hypothermia-treated HIE. These results highlight the importance of evaluating both motor activities and EF to understand children's everyday challenges.

Enteral Feeding in Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

 This study aimed to describe feeding outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) and compare characteristics and outcomes in groups discharged home on oral, total/partial nasogastric, and gastrostomy tube feedings.

STUDY DESIGN

 This was a retrospective, single-center cohort study of infants diagnosed with moderate or severe HIE using standard criteria who underwent cooling from January 2017 to June 2022. Data were abstracted from hospital course as well as until 6 months follow-up. Statistical analysis included chi-square test and ANOVA with post hoc Bonferroni correction for between-group comparisons.

RESULTS

 Among 123 included infants, 95 (77%) fed orally, 11 (9%) required total/partial nasogastric feeds and 17 (14%) had gastrostomy tubes at discharge. A significantly greater proportion of infants with gastrostomy-tube feeds at discharge had intrapartum complications, Apgar scores <5 at 5 and 10 minutes, severe rather than moderate HIE, and seizures. They also had a longer hospital stay, prolonged respiratory support and intubated days, and delayed initiation of feeding. Infants discharged on nasogastric feeds all attained oral feeds at a median (IQR) duration of 54 (6-178) days follow-up. Among the 106 (86%) infants with follow-up data, the gastrostomy group had significantly lower median weight and head circumference centiles compared to the others. Criteria for gavage eligibility were met before discharge in 98 (80%) of the cohort; 42% stayed beyond this benchmark.

CONCLUSION

 Earlier identification of eventual gastrostomy tube insertion as well as discharge home on nasogastric feedings may reduce duration of hospitalization in infants with HIE. Our data may provide insights to guide practice improvement for enteral feedings in this population.

KEY POINTS

· In neonatal encephalopathy, impaired oral feedings is common.. · Antepartum complications and HIE severity are associated with gastrostomy insertion.. · Discharge home on gavage feeds could shorten hospital stay..

Neonatal deep medullary venous thrombosis radiographic severity is associated with neurodevelopmental impairment

Deep medullary vein thrombosis (DMVT) is an increasingly recognized etiology of neonatal brain injury, but remains poorly understood. Our study aimed to assess the association between MRI severity and neurodevelopmental impairment (NDI) in neonates with DMVT, and develop a novel MRI grading system that might inform clinical outcomes. We retrospectively reviewed relevant charts from infants admitted to our tertiary care hospital between January 1990 to March 2023, and evaluated clinical characteristics, MRI features, and neurodevelopmental assessments of this cohort. We developed and validated a simple MRI grading system based on injury severity, categorizing lesions into mild, moderate, or severe groups. Of the 63 neonates with a diagnosis of DMVT, 41 had moderate or severe MRI lesions; those patients were 24-fold more likely to experience NDI compared to those with mild injury (adjusted OR 24.3, 95% CI 4.7-180.2, p<0.001). Of the 52 infants with follow-up data, 40.4% developed NDI; MRI severity was the strongest predictor of impaired outcomes, independent of clinical factors including gestational age, Apgar score and seizures at presentation. Our findings suggest that this pragmatic MRI grading scheme may offer clinicians and researchers a valuable classification and prognostication tool.

Therapeutic hypothermia for neonatal hypoxic ischaemic encephalopathy in Sub-Saharan Africa: A scoping review

INTRODUCTION

There are divergent views and limited data regarding therapeutic hypothermia (TH) for neonatal hypoxic ischaemic encephalopathy (HIE) in sub-Saharan Africa (SSA). Our aim was to map and synthesize the published literature describing the use of TH for HIE in SSA, and the associated outcomes.

METHOD

We searched Pubmed, Scopus, Google Scholar, and Web of Science from 1 January 1996 to 31 December 2023 for research studies, protocols, feasibility studies and surveys on term and near-term babies with HIE (population) treated with TH (concept) in SSA (context).

RESULTS

Thirty records were included: Three surveys, one feasibility study and 26 publications describing 23 studies of 21 cohorts, cooling 1420 babies in South Africa, Uganda, and Ghana. There were five studies recruiting at follow-up, five pilot studies, one randomised controlled trial, one case series, and 10 birth cohorts. The methods and design of the studies were highly variable and often inadequate. Only three studies with adequately described and validated cooling methods, non-selective sequential recruitment, and neurological outcomes were identified. Two studies of babies from birth, both with intensive care facilities, reported survival with normal/mildly abnormal outcome in 71% at discharge in one study, and 71% at 12 months in another, with 16% cerebral palsy (CP) in survivors, and only 16% loss to follow-up. The third study, which only included clinic attenders after TH without intensive care, reported 7% CP in survivors, but 36% loss to follow-up.

CONCLUSIONS

Data from the adequately described TH studies in SSA indicate outcomes at discharge and twelve months which are similar to global norms. However, these data are limited to South Africa. Interpretation of other studies was limited by loss to follow-up, variable methodology and exclusion of babies with severe HIE in some studies. There is a need for standardised definitions to facilitate interpretation in TH studies.

Survival Status and Predictors of Mortality Among Asphyxiated Neonates Admitted to Jimma University Medical Center, Southwest Ethiopia: A Retrospective Cohort Study

Background and Aims

Perinatal asphyxia is the second leading cause of neonatal mortality in sub-Saharan African countries, including Ethiopia. This study aimed to assess survival status and predictors of mortality among neonates admitted to Jimma University Medical Center with perinatal asphyxia.

Methods

A retrospective cohort study was conducted on 373 asphyxiated neonates admitted to Jimma University Medical Center from April 12, 2019, to May 5, 2022. Data were collected from May 18 to June 3, 2022, entered into Epidata version 3.1, and analyzed using R software version 4.2.1. On univariate Cox regression, variables with a p < 0.25 were selected for the final model. Multivariate Cox regression was used to identify significant predictors of mortality among asphyxiated neonates at a 0.05 level of significance and a corresponding 95% confidence interval of the adjusted hazard ratio.

Results

The median survival time of the participants was 20 (95% CI: 18-23) days. During 2888 days of total person-time at risk, a 29.09 (95% CI: 23.20-36.01) per 1000 person-days incidence rate of neonatal mortality was identified. The significant predictors of mortality were stage III Hypoxic ischemic encephalopathy (AHR: 3.46, 95% CI: 1.55-7.70), acute kidney injury (AHR: 2.82, 95% CI: 1.28-6.23), and stress ulcers (AHR: 2.24, 95% CI: 1.26-3.97).

Conclusion

The incidence of mortality was relatively high among the study participants. Stage III Hypoxic ischemic encephalopathy, acute kidney injury, and stress ulcers were significant predictors.

Renal Regional Oxygen Saturation and Acute Kidney Injury in Neonates with Perinatal Asphyxia

OBJECTIVE

 Neonates with moderate-to-severe perinatal asphyxia often develop acute kidney injury (AKI). Additionally, therapeutic hypothermia (TH) can affect renal blood flow. This study aimed to evaluate the association between renal regional oxygen saturation (rSrO2) during TH and AKI in neonates with moderate and severe perinatal asphyxia.

STUDY DESIGN

 This retrospective longitudinal study included neonates with moderate-to-severe asphyxia who required TH. The primary outcome was the occurrence of AKI, classified as a rate of decrease in creatinine levels of <33% at 72 hours of TH. rSrO2 was continuously monitored by near-infrared spectroscopy during the hypothermia and rewarming phases. Data analysis involved dividing the average rSrO2 levels into 12-hour periods. We analyzed the association between AKI and rSrO2 levels using univariate and multivariate logistic regression models. Furthermore, we assessed the predictive capacity of rSrO2 for AKI by analyzing the area under the receiver operating characteristic curve.

RESULTS

 Ninety-one patients were included in the study. On average, patients with AKI exhibit lower rSrO2 levels during TH. Specifically, rSrO2 levels within the first 12 hours and between 25 and 72 hours of TH demonstrated the highest predictive capability for AKI. Multivariate logistic regression analysis revealed that rSrO2 levels within the initial 12 hours (adjusted odds ratio [aOR] = 1.11, 95% confidence interval [CI]: 1.01-1.21) and between 61 and 72 hours (aOR = 0.85, 95% CI: 0.78-0.92) were significantly associated with AKI.

CONCLUSION

 An increase in rSrO2 during the first 12 hours of TH and lower rSrO2 levels between 61 and 72 hours of treatment were associated with the development of AKI in asphyxiated neonates undergoing TH.

KEY POINTS

· Neonates with asphyxia often develop AKI.. · Renal saturations are affected by hypothermia and asphyxia. · Patients with AKI initially show higher rSrO2, then lower rSrO2.. · Monitoring rSrO2 identifies early AKI..

Quercetin alleviates neonatal hypoxic-ischaemic brain injury by rebalancing microglial M1/M2 polarization through silent information regulator 1/ high mobility group box-1 signalling

Neonatal hypoxic-ischaemic encephalopathy (HIE) remains one of the major causes of neonatal death and long-term neurological disability. Due to its complex pathogenesis, there are still many challenges in its treatment. In our previous studies, we found that quercetin can alleviate neurological dysfunction after hypoxic-ischaemic brain injury (HIBI) in neonatal mice. As demonstrated through in vitro experiments, quercetin can inhibit the activation of the TLR4/MyD88/NF-κB signalling pathway and the inflammatory response in the microglial cell line BV2 after oxygen-glucose deprivation. However, the in-depth mechanism still needs to be further elucidated. In the present study, 7 day-old neonatal ICR mice or BV2 cells were treated with quercetin with or without the SIRT1 inhibitor EX527 via neurobehavioural, histopathological and molecular methods. In vivo experiments have shown that quercetin can significantly improve the performance of HI mice in behavioural tests, such as the Morris water maze, rotarod test and pole climbing test, and reduce HI insult-induced structural brain damage, cell apoptosis and hippocampal neuron loss. Quercetin also inhibited the immunofluorescence intensity of the microglial M1 marker CD16 + 32 and significantly downregulated the expression of the M1-related proteins iNOS, IL-1β and TNF-α. Moreover, quercetin increased the immunofluorescence intensity of the microglial M2 marker CD206 and significantly increased the expression of the M2-related proteins Arg-1 and IL-10. In addition, quercetin limits the nucleocytoplasmic translocation and release of microglial HMGB1 and further suppresses the activation of the downstream TLR4/MyD88/NF-κB signalling pathway. The above effects of quercetin are partially weakened by pretreatment with EX527. Similar results were found in in vitro experiments, and the mechanism further revealed that the rebalancing effect of quercetin on microglial polarization is achieved through the SIRT1-mediated reduction in HMGB1 acetylation levels. This study provides new and complementary insights into the neuroprotective effects of quercetin and a new direction for the treatment of neonatal HIE.

Individualized Neuroprognostication in Neonates With Hypoxic-Ischemic Encephalopathy Treated With Hypothermia

Background and Objectives

To determine whether post-rewarming brain MRI enables individualized domain-specific prediction of neurodevelopmental outcomes at 2 years of age in infants treated with hypothermia for hypoxic-ischemic brain injury.

Methods

We conducted a retrospective multicenter study of infants with moderate-to-severe hypoxic-ischemic encephalopathy (HIE) treated with hypothermia. Brain MRI abnormalities and the prediction of domain-specific 2-year neurodevelopmental outcomes were scored independently by 2 investigators after which consensus was reached for both imaging findings and outcome prediction. Neuroimaging patterns were categorized as normal, white matter (WM)/watershed-predominant, deep gray matter (DGM)-predominant, and near-total injury. Outcomes were predicted separately for mortality, cerebral palsy (CP) type and severity, cognitive delay, epilepsy, cerebral visual impairment (CVI), and feeding difficulties; these outcomes were predicted as highly unlikely, possible, probable, or highly likely.

Results

Of the 152 study infants, 27 (18%) died. The neurodevelopmental outcome at 2 years was available in all 125 survivors. CP was seen in 21 of 125 surviving infants (17%). No infants in the highly unlikely category developed CP while 90% in the highly likely category did. When CP was predicted as possible, 40% developed CP; all were mild and ambulatory. When CP was predicted as probable, 67% developed CP of whom 40% were severe and nonambulatory. Cognitive scores were available in 104 of 125 infants (83%). Cognitive delay was seen in 23 of 104 infants (22%) (15% mild and 7% severe). When cognitive delay was predicted as highly unlikely, 92% did not develop cognitive delay and the delay was mild in those who did. When cognitive delay was considered highly likely, this developed in 100%. When epilepsy, CVI, and feeding problems were predicted as highly unlikely, 98% did not develop epilepsy; for CVI and feeding problems, this was 100% and 97%, respectively. In 27 of 152 infants (18%), the investigators reached consensus that the overall injury was severe enough to consider redirection of care; 21 of 27 infants (78%) died. Of the survivors, 5 infants developed severe CP and 1 had a mild dyskinetic CP with swallowing problems and CVI.

Discussion

Individualized domain-specific categorical neuroprognostication mainly based on brain MRI is feasible, reliable, and highly accurate in infants with HIE.

Association between cerebrospinal fluid levels of neuro-specific enolase after hypothermia alone and in combination with neurodevelopmental outcomes at age six years

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is still associated with death and sequelae including cerebral palsy and intellectual disability despite induced hypothermia. Biomarkers, as early predictive indicators of adverse outcomes, are lacking.

AIMS

To investigate whether post-rewarming cerebrospinal fluid (CSF)-neuro-specific enolase (NSE) levels after hypothermia are associated with neurodevelopmental outcomes at age six years, alone or when combined with amplitude-integrated electroencephalography (aEEG) and brain magnetic resonance imaging (MRI), as neuroimaging and neurophysiological indicators, respectively.

PARTICIPANTS

We retrospectively enrolled 157 patients with HIE from 2011 to 2018 with available post-rewarming CSF-NSE levels and developmental tests at age six years. Of these, 148 met the inclusion criteria, and 87 were evaluated in the final analysis.

OUTCOME MEASURES

Multivariate receiver operating characteristic analysis determined the predictive ability of post-rewarming CSF-NSE levels for adverse outcomes including death and cerebral palsy, intellectual disability, and borderline disability at age 6 years either singly or in combination with aEEG and MRI findings, using logistic regression analysis.

RESULTS

The cut-off value for CSF-NSE at a median 5 days after birth was 233 ng/dL (area under the curve 0.97, 95 % confidence intervals of 0.93-1.00, sensitivity 1, specificity 0.94) for death. Regarding cerebral palsy and intellectual disability, the combination of abnormal aEEG at 72 h, moderate-severe MRI injury findings, and with or without CSF-NSE (cut-off value: 55 ng/mL), odds ratio (95 % confidence intervals) improving from 8.6 (2.7-27.8) to 12.4 (3.5-43.9) (p < 0.01).

CONCLUSIONS

In patients with HIE, post-rewarming CSF-NSE levels were associated not only with death independently but with cerebral palsy and intellectual disability in combination with EEG and MRI findings.

Predictors for Development of Asphyxiated Neonates Treated With Therapeutic Hypothermia

AIM

To describe the long-term neurodevelopmental outcomes of asphyxiated neonates treated with hypothermia in association with neonatal magnetic resonance imaging (MRI) findings.

METHODS

We evaluated, retrospectively, clinical and radiological single-centre data at 0, 2, and 5 years of age of 53 asphyxiated neonates born between 2005 and 2015. Neonatal cranial MRI was re-evaluated using the Weeke score ranging from 0 (normal finding) to 55 (cerebral devastation) by a single neuroradiologist blinded to patient outcomes. Neurodevelopmental outcomes were evaluated using the Bayley Scales of Infant Development (BSID) at 2 years, and tests assessing intellectual performance at 5 years of age.

RESULTS

Of the 191 asphyxiated neonates treated with hypothermia, 53 returned for their 5-year follow-up. There were 10 children with MRI scores ≥ 10, all of whom had epilepsy, 9 had severe cognitive impairment, and 9 had cerebral palsy. In contrast, MRI scores < 10 were poorly predictive of later development. BSID at 2 years of age showed good correlation with IQ scores at 5 years of age (Rs = 0.58, p < 0.001).

CONCLUSION

The Weeke score can be used to identify severely impaired children in the neonatal period. In contrast, the neurocognitive test results at 2 years of age were indicative of mild or moderate impairment at 5 years of age.

Effects of Resuscitation and Simulation Team Training on the Outcome of Neonates with Hypoxic-Ischemic Encephalopathy in South Tyrol

Background/Objectives: Neonatal hypoxic-ischemic encephalopathy (HIE) due to perinatal complications remains an important pathology with a significant burden for neonates, families, and the healthcare system. Resuscitation and simulation team training are key elements in increasing patient safety. In this retrospective cohort study, we evaluated whether regular constant training of all personnel working in delivery rooms in South Tyrol improved the outcome of neonates with HIE. Methods: We retrospectively analyzed three groups of neonates with moderate to severe HIE who required therapeutic hypothermia. The first group included infants born before the systematic introduction of training and was compared to the second group, which included infants born after three years of regular training. A third group, which included infants born after the SARS-CoV-2 pandemic, was compared with the previous two to evaluate retention of skills and the long-term effect of our training program. Results: Over the three study periods, mortality decreased from 41.2% to 0% and 14.3%, respectively. There was also a significant reduction of patients with subclincal seizures detected only through EEG, from 47.1% in the first period to 43.7% and 14.3% in the second and third study periods, respectively. Clinical manifestations of seizures decreased significantly from 47.1% to 37.5% and 10.7%, respectively, as well as severe brain lesions in ultrasound (US) and MRI. Conclusions: In this study, constant and regular simulation training for all birth attendants significantly decreases mortality and improves the outcome in neonates with moderate to severe HIE. This positive effect seems to last even after a one-year period during which training sessions could not be performed due to the COVID-19 pandemic.

Changes in the treatment and outcomes of different severities of neonatal hypoxic ischemic encephalopathy in California: a retrospective cohort study

OBJECTIVE

Evaluate the changes in management and outcomes of Californian infants with hypoxic ischemic encephalopathy (HIE).

STUDY DESIGN

Infants with HIE were identified from a California administrative birth cohort using ICD codes and divided into two epochs, Epoch 1 (2010-2015) and Epoch 2 (2016-2019). Risk ratios (RR) for induced hypothermia (IH) in each epoch and their outcomes were calculated using log-linear regression.

RESULTS

In this cohort, 4779 infants with HIE were identified. Incidence of HIE in California increased yearly from 0.5/1000 California births to a peak of 1.5/1000 births in 2018. The use of IH in infants with mild HIE increased in Epoch 2 compared to Epoch 1. There was no significant difference in outcomes between epochs for infants with mild HIE that received IH including no difference in neonatal seizures.

CONCLUSION

Significantly more infants with mild HIE received IH since 2015 in California, but no significant difference in outcomes.

Cardiovascular Performance in Neonates with Hypoxic-Ischemic Encephalopathy Under Therapeutic Hypothermia: Evaluation by Conventional and Advanced Echocardiographic Techniques

This study aimed to evaluate the hemodynamic and ventricular performance of neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia using conventional and advanced echocardiographic techniques. This observational, prospective study included 22 neonates with HIE matched with 22 healthy neonates. Echocardiographic studies were performed 24 h after achieving target temperature during hypothermia and 24 h after rewarming. Evaluated echocardiographic parameters included ejection fraction (EF), shortening fraction (SF), right ventricular fractional area change, biventricular Tei index, right ventricular s' wave velocity, tricuspid annular plane systolic excursion, biventricular stroke volume and cardiac output, left ventricular (LV) and right ventricular (RV) global longitudinal strain (GLS), LV circumferential and radial strain, LV twist, and LV torsion. LV EF and SF did not change significantly between the hypothermia and rewarming periods (EF:73 ± 7% vs. 74 ± 5%, p = 0.21; SF:39 ± 6% vs. 41 ± 5%, p = 0.26); however, both were higher after rewarming compared to the control group (EF:70 ± 5%, p = 0.003; SF:36 ± 4%, p = 0.002). There were no significant differences in LV GLS, circumferential and radial strain, twist, and torsion between the HIE and control groups. Pulmonary artery systolic pressure (PASP) and RV GLS were worse in the study group compared to the control group (PASP: hypothermia 45 ± 24 mmHg, p = 0.01; rewarming 53 ± 34 mmHg, p = 0.01; control group 29 ± 11 mmHg; RV GLS: hypothermia 18 ± 5%, p = 0.02; rewarming: 18 ± 4%, p = 0.01; control group 21 ± 2%). Therapeutic hypothermia appears to have no detrimental impact on LV systolic function. RV GLS was the only parameter that demonstrated impaired RV systolic function during therapeutic hypothermia, likely due to elevated PASP.

Role of the very low frequencies of the renal oxygen saturation signal in acute kidney injury in newborns with perinatal asphyxia

Objective

Renal autoregulation, hemodynamic response, and endothelial dysfunction play significant roles in acute kidney injury (AKI) during perinatal asphyxia. A third mechanism of autoregulation, involving very low-frequency oscillations, has been described. This study aimed to evaluate the relationship between the power of the very low-frequency component of the Fast Fourier Transform (FFT) and AKI during therapeutic hypothermia (TH) treatment in neonates with perinatal asphyxia.

Study design

A retrospective longitudinal study was conducted on neonates with moderate and severe perinatal asphyxia. AKI was defined as a decrease of less than 33% in the serum creatinine level by day 3. The power of the very low-frequency component in the FFT was assessed by analyzing renal oxygen saturation using near-infrared spectroscopy (NIRS), focusing on a frequency band of approximately 0.01 Hz. Bivariate analyses were performed to explore the association between the power of the very-low-frequency component and AKI. The predictive ability of this component for AKI was evaluated using a receiver operating characteristic (ROC) curve. Additionally, a generalized estimating equation (GEE) was developed to investigate whether changes in the power of the very-low-frequency component during treatment differed according to the presence of AKI.

Results

A total of 91 patients were included in the study, of whom 15 (16.5%) developed AKI. Neonates with AKI exhibited a significantly lower power of the very low-frequency component on the second day of treatment (p = 0.001). This component demonstrated good predictive ability for AKI (ROC curve 0.77, 95% CI 0.63-0.90).

Conclusion

Among neonates with perinatal asphyxia who developed AKI, a lower power of the very-low-frequency component in FFT (approximately 0.01 Hz) was observed on the second day of therapeutic hypothermia. This finding suggests that alterations in very-low-frequency oscillations may reflect endothelial dysfunction and contribute to the development of AKI, warranting further investigation in larger cohorts.

Physiological and behavioral stability of newborns on therapeutic hypothermia for hypoxic-ischemic encephalopathy during parental holding

BACKGROUND

Physical separation contributes to parental trauma and poor bonding in the context of therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE). Parental holding (PH) may improve parents' experience. We aim to determine the physiological and behavioral stability of the newborn held by the parents during TH.

METHODS

Observational, prospective, single-center study which included 30 newborns with mean gestational age of 39 (1.8) weeks and mean birth weight 3165 (508) g, with HIE treated by TH, whom parents wanted to hold. All infants were mechanically ventilated and received sedation-analgesia. Main outcome was change in body temperature (> 34°C or < 33 °C) during PH. Secondary outcomes were change in vital signs and behavior (comfort/pain scores) during PH. Parental and nurses' opinions were assessed by a self-reporting questionnaire with a 10-point Likert scale.

RESULTS

We found no significant changes in temperature, other vital signs or in infants' COMFORT-B score during parental holding. Responses to self-reporting questionnaires completed by parents and nurses showed a high level of overall effectiveness and satisfaction with PH.

CONCLUSION

Parents holding newborns undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy was safe for the newborn without causing discomfort. It was also beneficial for the parents and supported by the healthcare team.

IMPACT

Parents holding newborns undergoing therapeutic hypothermia for Hypoxic Ischemic Encephalopathy was feasible without causing discomfort. It was also beneficial for the parents and supported by the healthcare team. Infants' temperature or other vital signs did not change during parental holding, which was found very satisfactory by parents and healthcare givers, showing that parental holding is feasible. This study promotes further dissemination of parental holding, which may limit the detrimental effect of physical separation for parents of newborns undergoing therapeutic hypothermia.

Hydrogen gas inhalation ameliorates glomerular enlargement after hypoxic-ischemic insult in asphyxiated piglet model

Acute kidney injury (AKI) has been reported to occur in 30-70% of asphyxiated neonates. Hydrogen (H2) gas became a major research focus in neonatal medicine after the identification of its robust antioxidative properties. However, the ability of H2 gas to ameliorate AKI is unknown. We examined histopathological injuries in the piglet renal cortex on day 5 after a hypoxic-ischemic (HI) insult and if H2 gas can alleviate kidney injuries. Twenty piglets were divided into three groups: no insult (Control, n = 6), HI insult alone (HI, n = 8), and HI insult with H2 gas ventilation (HI-H2, 2.1-2.7% for 24 h, n = 6). The total glomerular cell count was significantly higher in the HI group than in the other groups, with no difference between the HI-H2 and control groups. Proximal tubular lumen narrowing was significantly increased in the HI group versus control, but not in the HI-H2 group. In this piglet model, glomerular enlargement with an increase in glomerular cell number due to tubular lumen narrowing was observed on day 5 after HI insult. H2 gas effectively suppressed this glomerular cell increase and tubular lumen narrowing.

Redirection of Care for Neonates with Hypoxic-Ischemic Encephalopathy Receiving Therapeutic Hypothermia

Background/Objectives: Hypoxic-ischemic encephalopathy (HIE) in late preterm and term neonates accounts for neonatal mortality and unfavorable neurodevelopmental outcomes in survivors despite therapeutic hypothermia (TH) for neuroprotection. The circumstances of death in neonates with HIE, including involvement of neonatal palliative care (NPC) specialists and neurodevelopmental follow-up at 18-24 months in survivors, warrant further evaluation. Methods: A retrospective multicenter cohort study including neonates ≥ 35 weeks gestational age with moderate to severe HIE receiving TH, registered in the Swiss National Asphyxia and Cooling Register between 2011 and 2021. Neurodevelopmental follow-up at 18-24 months in survivors was assessed. The groups of survivors and deaths were compared regarding perinatal demographic and HIE data. Prognostic factors leading to redirection of care (ROC) were depicted. Results: A total of 137 neonates were included, with 23 (16.8%) deaths and 114 (83.2%) survivors. All but one death (95.7%) occurred after ROC, with death on a median of 3.5 (2-6) days of life. Severe encephalopathy was indicated by a Sarnat score of 3 on admission, seizures were more frequent, and blood lactate values were higher on postnatal days 1 to 4 in neonates who died. Lactate in worst blood gas analysis (unit-adjusted odds ratio 1.25, 95% CI 1.02-1.54, p = 0.0352) was the only variable independently associated with ROC. NPC specialists were involved in one case. Of 114 survivors, 88 (77.2%) had neurodevelopmental assessments, and 21 (23.9%) of those had unfavorable outcomes (moderate to severe disability). Conclusions: Death in neonates with moderate to severe HIE receiving TH almost exclusively occurred after ROC. Parents thus had to make critical decisions and accompany their neonate at end-of-life within the first week of life. Involvement of NPC specialists is encouraged in ROC so that there is continuity of care for the families whether the neonate survives or not.

The impact of clinical seizures and adverse brain MRI patterns in neonates with hypoxic-ischemic encephalopathy and abnormal neurodevelopment

INTRODUCTION

This study aimed to investigate the associations among seizures, clinical characteristics, and brain injury on Magnetic Resonance Imaging (MRI) in infants with Hypoxic Ischemic Encephalopathy (HIE), and to determine whether these findings can predict unfavorable neurodevelopmental outcomes.

METHOD

Clinical and electrographic seizures were assessed by amplitude-integrated electroencephalogram, and the extent of brain injury was evaluated by using MRI. At 12‒24 months of age, developmental impairment or death was assessed. Between 2012 and 2020, 143 newborns were admitted for HIE, and 8 infants were excluded from the study.

RESULTS

Eighty-five infants were diagnosed with greater than moderate HIE and 65 infants underwent therapeutic hypothermia. In addition, 38 infants experienced clinical seizures (clinical seizure group, CSG), 49 infants had electrographic seizures (Electrographic Seizure Group, ESG), and 48 infants had no seizures (no seizure group, NSG). The proportion of infants with neurodevelopmental impairment or death was significantly higher in the CSG than in the NSG (57.7 % and 26.1 %, p = 0.026). A risk factor analysis indicated that cord blood pH (adjusted Odds Ratio [aOR = 0.01]; 95 % Confidence Interval [95 % CI 0.001‒0.38]; p = 0.015) and MRI findings (aOR = 4.37; 95 % CI 1.25‒15.30; p = 0.012) were independently associated with abnormal neurodevelopment, after adjustment.

DISCUSSION

Clinical seizures in infants with HIE were independently associated with abnormal neurodevelopment. However, cord blood pH and abnormal brain MRI findings were consistently linked to long-term neurodevelopmental outcomes.

Therapeutic hypothermia in preterm infants under 36 weeks: Case series on outcomes and brain MRI findings

PURPOSE

Perinatal hypoxic-ischemic encephalopathy (HIE) is a significant cause of neonatal brain injury. Therapeutic hypothermia (TH) is the standard treatment for term neonates, but its safety and efficacy in neonates < 36 weeks gestational age (GA) remains unclear. This case series aimed to evaluate the outcomes of preterm infants with HIE treated with TH.

METHODS

Retrospective analysis of preterm infants (< 36w GA) treated with TH (01/2019-06/2024). Data on demographics, clinical complications, coagulation profiles, brain magnetic resonance imaging (MRI), and neurodevelopment outcomes were analyzed.

RESULTS

Seventeen patients were included (range 32.5-35.5w, median 34.4; birthweight range 1556-2493 g, median 2300 g), 58.8% were male. Placental abruption was identified in 7 cases (41.2%), and 8 (47.1%) required advanced resuscitation. Thirteen patients (76.5%) presented anemia, 12 (70.6%) coagulopathy, 9 (52.9%) thrombocytopenia, and 9 (52.9%) acute liver failure. Hypofibrinogenemia (< 1 g/L) was significantly associated with severe intracranial hemorrhage (ICH), defined as extracerebral, intraventricular or parenchymal hemorrhage causing mass effect. MRI findings were classified based on the predominant lesion: I- hypoxic-ischemic injury, II- severe ICH, or III- normal/mild findings. Severe ICH was the predominant lesion in 4 cases (23.5%). White matter injury was seen in 12 (76%). Death occurred in 8 cases (47.1%). Of the 9 surviving patients, at 2 years, 6 (66.7%) had normal neurodevelopment, while 1 (11.1%) had severe disability.

CONCLUSION

Coagulation abnormalities, particularly hypofibrinogenemia, significantly increase the risk of severe ICH in < 36w infants treated with TH. The safety and efficacy of TH in this population require further investigation.

Consensus definition and diagnostic criteria for neonatal encephalopathy-study protocol for a real-time modified delphi study

BACKGROUND

'Neonatal encephalopathy' (NE) describes a group of conditions in term infants presenting in the earliest days after birth with disturbed neurological function of cerebral origin. NE is aetiologically heterogenous; one cause is peripartum hypoxic ischaemia. Lack of uniformity in the terminology used to describe NE and its diagnostic criteria creates difficulty in the design and interpretation of research and complicates communication with families. The DEFINE study aims to use a modified Delphi approach to form a consensus definition for NE, and diagnostic criteria.

METHODS

Directed by an international steering group, we will conduct a systematic review of the literature to assess the terminology used in trials of NE, and with their guidance perform an online Real-time Delphi survey to develop a consensus diagnosis and criteria for NE. A consensus meeting will be held to agree on the final terminology and criteria, and the outcome disseminated widely.

DISCUSSION

A clear and consistent consensus-based definition of NE and criteria for its diagnosis, achieved by use of a modified Delphi technique, will enable more comparability of research results and improved communication among professionals and with families.

IMPACT

The terms Neonatal Encephalopathy and Hypoxic Ischaemic Encephalopathy tend to be used interchangeably in the literature to describe a term newborn with signs of encephalopathy at birth. This creates difficulty in communication with families and carers, and between medical professionals and researchers, as well as creating difficulty with performance of research. The DEFINE project will use a Real-time Delphi approach to create a consensus definition for the term 'Neonatal Encephalopathy'. A definition formed by this consensus approach will be accepted and utilised by the neonatal community to improve research, outcomes, and parental experience.

A Comparison of Automatically Extracted Quantitative EEG Features for Seizure Risk Stratification in Neonatal Encephalopathy

PURPOSE

Seizures occur in up to 40% of neonates with neonatal encephalopathy. Earlier identification of seizures leads to more successful seizure treatment, but is often delayed because of limited availability of continuous EEG monitoring. Clinical variables poorly stratify seizure risk, and EEG use to stratify seizure risk has previously been limited by need for manual review and artifact exclusion. The goal of this study is to compare the utility of automatically extracted quantitative EEG (qEEG) features for seizure risk stratification.

METHODS

We conducted a retrospective analysis of neonates with moderate-to-severe neonatal encephalopathy who underwent therapeutic hypothermia at a single center. The first 24 hours of EEG underwent automated artifact removal and qEEG analysis, comparing qEEG features for seizure risk stratification.

RESULTS

The study included 150 neonates and compared the 36 (23%) with seizures with those without. Absolute spectral power best stratified seizure risk with area under the curve ranging from 63% to 71%, followed by range EEG lower and upper margin, median and SD of the range EEG lower margin. No features were significantly more predictive in the hour before seizure onset. Clinical examination was not associated with seizure risk.

CONCLUSIONS

Automatically extracted qEEG features were more predictive than clinical examination in stratifying neonatal seizure risk during therapeutic hypothermia. qEEG represents a potential practical bedside tool to individualize intensity and duration of EEG monitoring and decrease time to seizure recognition. Future work is needed to refine and combine qEEG features to improve risk stratification.

Intrapartum electronic fetal heart rate monitoring to predict acidemia at birth with the use of deep learning

BACKGROUND

Electronic fetal monitoring is used in most US hospital births but has significant limitations in achieving its intended goal of preventing intrapartum hypoxic-ischemic injury. Novel deep learning techniques can improve complex data processing and pattern recognition in medicine.

OBJECTIVE

This study aimed to apply deep learning approaches to develop and validate a model to predict fetal acidemia from electronic fetal monitoring data.

STUDY DESIGN

The database was created using intrapartum electronic fetal monitoring data from 2006 to 2020 from a large, multisite academic health system. Data were divided into training and testing sets with equal distribution of acidemic cases. Several different deep learning architectures were explored. The primary outcome was umbilical artery acidemia, which was investigated at 4 clinically meaningful thresholds: 7.20, 7.15, 7.10, and 7.05, along with base excess. The receiver operating characteristic curves were generated with the area under the receiver operating characteristic assessed to determine the performance of the models. External validation was performed using a publicly available Czech database of electronic fetal monitoring data.

RESULTS

A total of 124,777 electronic fetal monitoring files were available, of which 77,132 had <30% missingness in the last 60 minutes of the electronic fetal monitoring tracing. Of these, 21,041 were matched to a corresponding umbilical cord gas result, of which 10,182 were time-stamped within 30 minutes of the last electronic fetal monitoring reading and composed the final dataset. The prevalence rates of the outcomes in the data were 20.9% with a pH of <7.2, 9.1% with a pH of <7.15, 3.3% with a pH of <7.10, and 1.3% with a pH of <7.05. The best performing model achieved an area under the receiver operating characteristic of 0.85 at a pH threshold of <7.05. When predicting the joint outcome of both pH of <7.05 and base excess of less than -10 meq/L, an area under the receiver operating characteristic of 0.89 was achieved. When predicting both pH of <7.20 and base excess of less than -10 meq/L, an area under the receiver operating characteristic of 0.87 was achieved. At a pH of <7.15 and a positive predictive value of 30%, the model achieved a sensitivity of 90% and a specificity of 48%.

CONCLUSION

The application of deep learning methods to intrapartum electronic fetal monitoring analysis achieves promising performance in predicting fetal acidemia. This technology could help improve the accuracy and consistency of electronic fetal monitoring interpretation.

The value of hypothermia as a neuroprotective and antiepileptic strategy in patients with status epilepticus: an update of the literature

INTRODUCTION

Status epilepticus represents a significant neurological emergency, with high morbidity and mortality rates. In addition to standard care, the identification of adjuvant strategies is essential to improve the outcome.

AREAS COVERED

The authors conducted a narrative review to provide an update on the value of hypothermia as an antiseizure and neuroprotective treatment in status epilepticus.

EXPERT OPINION

The use of targeted temperature management in the treatment of hypothermia in patients with status epilepticus represents a potentially promising adjuvant strategy, supported by a substantial body of experimental evidence. However, further clinical data demonstrating its efficacy are necessary before it can be recommended for routine use in targeted patient populations, such as those with refractory or super-refractory status epilepticus.

Effect Size of Targeted Temperature Management in Pediatric Patients with Post-Cardiac Arrest Syndrome According to the Severity

AIM

Few studies have investigated the differential effects of targeted temperature management (TTM) according to the severity of the condition in pediatric patients with post-cardiac arrest syndrome (PCAS). This study was aimed at evaluating the differential effects of TTM in pediatric patients with PCAS according to a risk classification tool developed by us, the rCAST.

METHODS

We used data from a nationwide prospective registry for out-of-hospital cardiac arrest (OHCA) patients in Japan. We classified eligible pediatric PCAS patients (aged ≤ 18 years) into quintiles based on their rCAST scores and evaluated the effect of TTM on the neurological outcomes in each severity group. Then, focusing on the severity group that appeared to benefit from TTM, we also evaluated the effect of TTM by propensity score analysis. Good neurological outcome was defined as a score on the Cerebral Performance Category or Pediatric Cerebral Performance Category scale of ≤2 at 30 days.

RESULTS

Among 1526 OHCA pediatric patients enrolled in the registry, the data of 307 PCAS patients were analyzed. None of the patients in the fifth quintile (rCAST ≥ 18.5) showed a good neurological outcome, regardless of whether they received TTM or not (0% [0/20] vs. 0% [0/73]). The propensity score analysis showed that TTM was significantly associated with a good neurological outcome in patients with rCAST scores in the first to fourth quintile (odds ratio: 1.21 [1.04-1.40], p = 0.014).

CONCLUSIONS

TTM was significantly associated with good neurological outcomes in pediatric PCAS patients with rCAST scores of ≤18.0.

Effects of Therapeutic Hypothermia and Minimal Enteral Nutrition on Short-Term Outcomes in Neonates with Hypoxic-Ischemic Encephalopathy: A 10-Year Experience from Oman

BACKGROUND

Therapeutic hypothermia (TH) is the standard treatment for moderate to severe hypoxic-ischemic encephalopathy (HIE) in developed countries, but data on its safety and efficacy in low-middle-income countries are limited and often conflicting. The impact of enteral feeding during TH remains inadequately explored. We aimed to examine TH's effects on mortality and brain injury and evaluate the safety and effectiveness of minimal enteral feeding during TH. Here, we report our single-center experience with TH over a 10-year period".

METHODS

A total of 187 neonates with moderate to severe HIE who underwent cooling were included in this retrospective study. Post-rewarming MRI scans were scored using a validated MRI scoring system. The primary outcomes were mortality and composite outcomes of mortality and brain injury.

RESULTS

The mortality rate was 3% in moderate and 25% in severe cases (p < 0.001). Overall, 85% (160/187) of neonates received minimal enteral nutrition. Multivariate regression analysis revealed that the severity of HIE at admission (OR 3.4 (1.03-11.6); p < 0.04) and gestational age (OR: 0.624 (0.442-0.882); p < 0.008) were independent predictors of composite outcomes of death and brain injuries. MRI score was a strong predictor of mortality (AUC: 0.89; p < 0.001) and of ability to orally feed at discharge (AUC: 0.73; p < 0.001).

CONCLUSIONS

Mortality rates associated with TH in infants with moderate-severe HIE align with those in high-income countries, and minimal enteral feeding during TH is safe. The severity of HIE, MRI scores, and feeding status are important predictors of outcomes.

Lack of additional benefit from slow rewarming after therapeutic hypothermia for ischaemic brain injury in near-term fetal sheep

The optimal rate of rewarming after therapeutic hypothermia is unclear. Slow rewarming may reduce cardiovascular instability and rebound seizures, but there is little controlled evidence to support this. The present study aimed to determine whether slow rewarming can improve neuroprotection after 72 h of hypothermia. Fetal sheep (0.85 gestation) received sham occlusion (n = 8) or 30 min of global cerebral ischaemia followed by normothermia (n = 7), or hypothermia from 3 to 72 h with either fast, spontaneous rewarming within 1 h (n = 8) or slow rewarming at 0.5°C h-1 over 10 h (n = 8). Hypothermia improved EEG and spectral edge recovery, with no significant difference between fast and slow rewarming. Hypothermia reduced the number of seizures, with no significant difference in seizure activity between fast and slow rewarming. Hypothermia improved neuronal survival in the cortex, CA1, CA3, CA4 and dentate gyrus regions of the hippocampus, with no significant difference between fast and slow rewarming. Hypothermia attenuated microglia counts in the cortex, with no significant difference between fast and slow rewarming. The rate of rewarming after a clinically relevant duration of hypothermia did not affect neurophysiological recovery, neuronal survival or attenuation of microglia after global cerebral ischaemia in term-equivalent fetal sheep. KEY POINTS: The rate of rewarming after 72 h of hypothermia did not affect recovery of EEG or spectral edge. There was no difference in the occurrence of seizures as a result of the rate of rewarming after hypothermia. The rate of rewarming after 72 h of hypothermia did not affect neuronal survival in the cortex or hippocampus.

Costs of Care for Neonates with Hypoxic-Ischemic Encephalopathy Treated with Therapeutic Hypothermia and Validation of the Canadian Neonatal Network Costing Algorithm

Objective

Therapeutic hypothermia (TH) is the standard treatment for neonates with hypoxic-ischemic encephalopathy (HIE). Validated cost estimates are required to better evaluate the cost-effectiveness of additional interventions during TH. The goal of this study is to identify clinical factors associated with costs of care and validate the Canadian Neonatal Network (CNN) costing algorithm for neonates with HIE receiving TH.

Study design

Single-center retrospective cohort study among neonates with HIE treated with TH in a tertiary neonatal intensive care unit from 2016 to 2018. Actual costs per patient were obtained from the hospital cost accounting system, Coût par Parcours de Soinset de Services, and linked to patient data. Estimated costs per patient were calculated using the CNN case-costing algorithm. Neonates were grouped into cost tertiles to identify characteristics of high resource users. Comparisons of actual costs and estimated costs were performed across 8 cost domains.

Results

Among 98 neonates treated with TH, 77 (79%) had mild-moderate HIE and 21 (21%) had severe HIE on admission. Factors associated with higher costs were severity of HIE and other markers of disease severity (seizures, mechanical ventilation, length of stay, and presence of brain injury on magnetic resonance imaging). Total median cost per neonate was $24,692 [IQR: $17,466; $39,234], which highly correlated with the CNN algorithm (median: $28 558 [IQR: $23 644; $40 704]) (R = 0.93, P < .01). The mean difference in total costs between estimates was $5339 (95% CI: $2697, $7981). There was a moderate-to-strong correlation between actual and estimated costs in 5/8 cost domains (R range: 0.68-0.98).

Conclusions

Severity of HIE and other markers of disease severity were associated with higher hospital costs. The CNN costing algorithm cost estimates for neonates with HIE treated with TH highly correlate with actual costs but overestimates the costs by approximately 15%.

Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy: Reducing Variability in Practice through a Collaborative Telemedicine Initiative

OBJECTIVE

 This study aimed to assess the viability of implementing a tele-educational training program in neurocritical care for newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia (TH), with the goal of reducing practice variation.

STUDY DESIGN

 Prospective study including newborns with HIE treated with TH from 12 neonatal intensive care units in Brazil conducted from February 2021 to February 2022. An educational intervention consisting of 12 biweekly, 1-hour, live videoconferences was implemented during a 6-month period in all centers. Half of the centers had the assistance of a remote neuromonitoring team. The primary outcome was the rate of deviations from TH protocol, and it was evaluated during a 3-month period before and after the intervention. Logistic regression via generalized estimating equations was performed to compare the primary and secondary outcomes. Protocol deviations were defined as practices not in compliance with the TH protocol provided. A subanalysis evaluated the differences in protocol deviations and clinical variables between centers with and without neuromonitoring.

RESULTS

 Sixty-six (39.5%) newborns with HIE were treated with TH during the preintervention period, 69 (41.3%) during the intervention period and 32 (19.1%) after intervention. There was not a significant reduction in protocol deviations between the pre- and postintervention periods (37.8 vs. 25%, p = 0.23); however, a decrease in the rates of missing Sarnat examinations within 6 hours after birth was seen between the preintervention (n = 5, 7.6%) and postintervention (n = 2, 6.3%) periods (adjusted odds ratio [aOR]: 0.36 [0.25-0.52], p < 0.001). Centers with remote neuromonitoring support had significantly lower rates of seizures (27.6 vs. 57.5%; aOR: 0.26 [0.12-0.55], p < 0.001) and significant less seizure medication (27.6 vs. 68.7%; aOR: 0.17 [0.07-0.4], p < 0.001).

CONCLUSION

 This study shows that implementing a tele-educational program in neonatal neurocritical care is feasible and may decrease variability in the delivery of care to patients with HIE treated with TH.

KEY POINTS

· Neurocritical care strategies vary widely in low- and middle-income countries.. · Heterogeneity of care may lead to suboptimal efficacy of neuroprotective strategies.. · Tele-education and international collaboration can decrease the variability of neurocritical care provided to infants with HIE..

Significant correlation between serum biomarkers and outcome in neonatal hypoxic-ischaemic encephalopathy

AIM

Associations between serum biomarkers S100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE) in neonates with hypoxic-ischaemic encephalopathy (HIE) offer contradicting data in regard to neurocognitive outcome. The aim of our study was to provide another dataset to answer this question if S100B or NSE correlates to outcome in neonatal HIE. In addition, we investigate whether amplitude-integrated EEG (aEEG) or magnetic resonance imaging (MRI) also has predictive value.

METHODS

In neonates with HIE born in Vorarlberg, Austria, (n = 34) from 2012to 2020, NSE and S100B serum levels were measured on day one. aEEG was installed at admission and MRI performed within 7 days. Surviving children (n = 27) were categorised as good or poor outcome by using an age-appropriate neurocognitive test and a standardised neurological follow-up. Positive and negative predictive values and receiver operating characteristic curves were calculated to evaluate the prognostic value.

RESULTS

S100B showed best positive and negative predictive value, 72.7% and 90.5%, respectively, and a significant area under the curve of 0.820. NSE showed a positive and a negative predictive value of 43.8% and 81.3% and an area under the curve of 0.757. Severely abnormal aEEG and abnormal MRI significantly correlated with outcome (p = 0.024 and 0.001 respectively).

CONCLUSION

S100B and NSE on day one, severely abnormal aEEG and abnormal MRI show a significant correlation and good predictive value for neurocognitive outcome.

Adjuvant High-Dose Erythropoietin With Delayed Therapeutic Hypothermia in Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

To evaluate the benefits of high-dose erythropoietin (EPO) combined with therapeutic hypothermia (TH) on brain magnetic resonance imaging (MRI) scores and neurodevelopmental outcomes in neonates with moderate to severe hypoxic-ischemic-ecephalopathy (HIE), especially in neonates who received TH between six to 12 hours of birth.

METHODS

This prospective, single-blind, randomized, placebo-controlled trial enrolled term newborns with moderate to severe HIE admitted to neonatal intensive care unit between April 2018 and April 2022. Hypothermia was started within 12 hours of birth. Infants were randomized to receive EPO 1000 U/kg or an equal volume of normal saline (placebo) on days 1, 2, 3, 5, and 7 of age in combination with hypothermia.

RESULTS

Fifty-seven neonates with moderate to severe HIE were recruited; 10 were excluded. Forty-seven patients were included: 32 received TH within six hours (group I) and in 15 TH was started within six to 12 hours of birth (group II). The clinical characteristics of mothers and infants, maternal complications, and resuscitations performed during the perinatal period showed no statistical differences between EPO group and placebo groups I and II. The MRI scores and brain injury patterns did not differ between the EPO and placebo groups. There is no statistical significance in either group's seizure and severe electroencephalography background (initial and after rewarming) between EPO and placebo in each group. There were no differences in developmental outcomes (abnormal Denver II > 2 area, Gross Motor Function Classification Score >1); Bayley Scales of Infant and Toddler Development, third edition (BSID-III) score (cognitive, language, and motor); or disability (hearing impairment and impaired vision) between the EPO and placebo groups I and II at 12 and 18 months.

CONCLUSIONS

Among term infants with moderate to severe HIE, TH with EPO administration, compared with TH alone, did not reduce brain injury on MRI or the risk of neurological sequelae both in patients who received TH within six hours and in those who received TH later (six to 12 hours). Further studies on the benefit of EPO injection alone or before TH in situations where TH cannot be performed are required.

Magnesium sulfate and risk of hypoxic-ischemic encephalopathy in a high-risk cohort

BACKGROUND

Hypoxic-ischemic encephalopathy contributes to morbidity and mortality among neonates ≥36 weeks of gestation. Evidence of preventative antenatal treatment is limited. Magnesium sulfate has neuroprotective properties among preterm fetuses. Hypertensive disorders of pregnancy are a risk factor for hypoxic-ischemic encephalopathy, and magnesium sulfate is recommended for maternal seizure prophylaxis among patients with preeclampsia with severe features.

OBJECTIVE

(1) Determine trends in the incidence of hypertensive disorders of pregnancy, antenatal magnesium sulfate, and hypoxic-ischemic encephalopathy; (2) evaluate the association between hypertensive disorders of pregnancy and hypoxic-ischemic encephalopathy; and (3) evaluate if, among patients with hypertensive disorders of pregnancy, the odds of hypoxic-ischemic encephalopathy is mitigated by receipt of antenatal magnesium sulfate.

STUDY DESIGN

We analyzed a prospective cohort of live births ≥36 weeks of gestation between 2012 and 2018 within the California Perinatal Quality Care Collaborative registry, linked with the California Department of Health Care Access and Information files. We used Cochran-Armitage tests to assess trends in hypertensive disorders, encephalopathy diagnoses, and magnesium sulfate utilization and compared demographic factors between patients with or without hypertensive disorders of pregnancy or treatment with magnesium sulfate. Hierarchical logistic regression models were built to explore if hypertensive disorders of pregnancy were associated with any severity and moderate/severe hypoxic-ischemic encephalopathy. Separate hierarchical logistic regression models were built among those with hypertensive disorders of pregnancy to evaluate the association of magnesium sulfate with hypoxic-ischemic encephalopathy.

RESULTS

Among 44,314 unique infants, the diagnosis of hypoxic-ischemic encephalopathy, maternal hypertensive disorders of pregnancy, and the use of magnesium sulfate increased over time. Compared with patients with hypertensive disorders of pregnancy alone, patients with hypertensive disorders treated with magnesium sulfate represented a high-risk population. They were more likely to be publicly insured, born between 36 and 38 weeks of gestation, be small for gestational age, have lower Apgar scores, require a higher level of resuscitation at delivery, have prolonged rupture of membranes, experience preterm labor and fetal distress, and undergo operative delivery (all P<.002). Hypertensive disorders of pregnancy were associated with hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.13-1.40]; P<.001) and specifically moderate/severe hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.42]; P<.001). Among patients with hypertensive disorders of pregnancy, treatment with magnesium sulfate was associated with 29% reduction in the odds of neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.71 [95% confidence interval, 0.52-0.97]; P=.03) and a 37% reduction in the odds of moderate/severe neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.63 [95% confidence interval, 0.42-0.94]; P=.03).

CONCLUSION

Hypertensive disorders of pregnancy are associated with hypoxic-ischemic encephalopathy and, specifically, moderate/severe disease. Among people with hypertensive disorders, receipt of antenatal magnesium sulfate is associated with a significant reduction in the odds of hypoxic-ischemic encephalopathy and moderate/severe disease in a neonatal cohort admitted to neonatal intensive care unit at ≥36 weeks of gestation. The findings of this observational study cannot prove causality and are intended to generate hypotheses for future clinical trials on magnesium sulfate in term infants.

Detection of neurologic changes in critically ill infants using deep learning on video data: a retrospective single center cohort study

Background

Infant alertness and neurologic changes can reflect life-threatening pathology but are assessed by physical exam, which can be intermittent and subjective. Reliable, continuous methods are needed. We hypothesized that our computer vision method to track movement, pose artificial intelligence (AI), could predict neurologic changes in the neonatal intensive care unit (NICU).

Methods

We collected video data linked to electroencephalograms (video-EEG) from infants with corrected age less than 1 year at Mount Sinai Hospital in New York City, a level four urban NICU between February 1, 2021 and December 31, 2022. We trained a deep learning pose recognition algorithm on video feeds, labeling 14 anatomic landmarks in 25 frames/infant. We then trained classifiers on anatomic landmarks to predict cerebral dysfunction, diagnosed from EEG readings by an epileptologist, and sedation, defined by the administration of sedative medications.

Findings

We built the largest video-EEG dataset to date (282,301 video minutes, 115 infants) sampled from a diverse patient population. Infant pose was accurately predicted in cross-validation, held-out frames, and held-out infants with respective receiver operating characteristic area under the curves (ROC-AUCs) 0.94, 0.83, 0.89. Median movement increased with age and, after accounting for age, was lower with sedative medications and in infants with cerebral dysfunction (all P < 5 × 10-3, 10,000 permutations). Sedation prediction had high performance on cross-validation, held-out intervals, and held-out infants (ROC-AUCs 0.90, 0.91, 0.87), as did prediction of cerebral dysfunction (ROC-AUCs 0.91, 0.90, 0.76).

Interpretation

We show that pose AI can be applied in an ICU setting and that an EEG diagnosis, cerebral dysfunction, can be predicted from video data alone. Deep learning with pose AI may offer a scalable, minimally invasive method for neuro-telemetry in the NICU.

Funding

Friedman Brain Institute Fascitelli Scholar Junior Faculty Grant and Thrasher Research Fund Early Career Award (F.R.). The Clinical and Translational Science Awards (CTSA) grant UL1TR004419 from the National Center for Advancing Translational Sciences. Office of Research Infrastructure of the National Institutes of Health under award number S10OD026880 and S10OD030463.

Analysis of CTG patterns in cases with metabolic acidosis at birth with and without neonatal neurological alterations

OBJECTIVE

To determine cardiotocographic patterns in newborns with metabolic acidosis, based on clinical signs of neurological alteration (NA) and the need for hypothermic treatment.

METHODS

All term newborns with metabolic acidosis in a single center from 2016 to 2020 were included in the study. Three segments of intrapartum CTG (cardiotocography) were considered (first 30 min of active labor, 90 to 30 min before birth, and last 30 min before delivery) and a longitudinal analysis of CTG pattern was performed according to the 2015 FIGO classification.

RESULTS

Three hundred and twenty-four neonates with metabolic acidosis diagnosed at birth were divided into three groups: the first group included all neonates with any clinical sign of neurological alteration, requiring hypothermia according to the recommendation of the Italian Society of Neonatology (group TNA-Treated neurological Alteration, n = 17), the second encompassed neonates with any clinical sign of neurological alteration not requiring hypothermia (group NTNA-Not Treated neurological Alteration, n = 83), and the third enclosed all neonates without any sign of clinical neurological involvement (group NoNA-No neurological Alteration, n = 224). The most frequent alterations of CTG in TNA group were late decelerations, reduced variability, bradycardia, and tachysystole. Unexpectedly, from the longitudinal analysis of the CTG, 49% of all cases with metabolic acidosis never showed a pathological CTG with normal trace at the beginning of labor followed by normal or suspicious trace in the final part of labor, the same as in TNA and NTNA groups (10 and 39%, respectively).

CONCLUSIONS

CTG has limited specificity in identifying cases of acidosis at birth, even in babies who will develop NA.

In-Hospital Outcomes of Neonates with Hypoxic-Ischemic Encephalopathy Receiving Sedation-Analgesia during Therapeutic Hypothermia

OBJECTIVE

 This study aimed to compare magnetic resonance imaging (MRI) severity scores and in-hospital outcomes among neonates with perinatal hypoxic-ischemic encephalopathy (HIE) with and without exposure to sedation-analgesia (SA) during therapeutic hypothermia (TH).

STUDY DESIGN

 A single-center, retrospective cohort study of neonates with perinatal HIE undergoing TH between January 2010 and December 2020. Demographics, clinical characteristics, MRI scores, and in-hospital outcomes were compared between patients without SA exposure and those with SA use.

RESULTS

 Of the 131 neonates, 55 (42%) did not have SA exposure, and 76 (58%) had SA during TH. Groups were similar in birth weight, gestational age, and severity of HIE. A higher proportion of neonates in the SA group received inhaled nitric oxide (iNO, 39.4% vs. 2%, p < 0.001) and vasopressors (41% vs. 20%, p = 0.012) compared to no SA group. There was no difference in median MRI severity scores for neither T1 (2 [2, 4.25] vs. 3 [2, 6], p = 0.295), T2 (2 [0, 3] vs. 3 [1.5, 5.5], p = 0.088) nor diffusion-weighted images (0 [0, 2] vs. 0 [0, 4.25], p = 0.090) between SA and no SA groups, respectively. In-hospital outcomes were similar between groups except for lower survival to discharge (87% vs. 98%, p = 0.020) in the SA group compared to those without SA. A regression analysis showed death was associated with the concomitant use of iNO (p < 0.001) and inotropes (p < 0.001).

CONCLUSION

 SA during TH for perinatal HIE did not alter early MRI severity scores. A lower survival to discharge in the SA group may be related to illness severity rather than SA use alone.

KEY POINTS

· Conflicting studies exist regarding the efficacy of SA use during TH.. · SA use during TH did not alter in-hospital MRI severity scores.. · SA use was associated with a lower survival to discharge, correlated to the severity of illness rather than SA use alone..

Neuroprotection for neonatal hypoxic-ischemic encephalopathy: A review of novel therapies evaluated in clinical studies

Therapeutic hypothermia is an effective therapy for moderate-to-severe hypoxic-ischemic encephalopathy (HIE) in infants born at term or near-term in high-resource settings. Yet there remains a substantial proportion of infants who do not benefit or who will have significant disability despite therapeutic hypothermia. Novel investigational therapies that may confer additional neuroprotection by targeting known pathogenic mechanisms of hypoxic-ischemic brain injury are under development. This review focuses on putative neuroprotective agents that have shown promise in animal models of HIE, and that have been translated to clinical studies in neonates with HIE. We include agents that have been studied both with and without concurrent therapeutic hypothermia. Our review therefore addresses not just neonatal HIE in high-resource countries where therapeutic hypothermia is the standard of care, but also neonatal HIE in low- and middle-income countries where therapeutic hypothermia has been shown to be ineffective, and where the greatest burden of HIE-related morbidity and mortality exists.

Therapeutic hypothermia success for hypoxic-ischaemic encephalopathy in Latin America: Eight-year experience in EpicLatino Neonatal Network

AIM

A study reported that therapeutic hypothermia (TH) did not reduce the combined prognosis of mortality and disability at 18 months, in low- and middle-income countries for patients with hypoxic ischaemic encephalopathy (HIE) who received TH, suggesting its no implementation in these regions. We described characteristics, mortality, and neurological response before and after the use of TH in newborns with HIE within the EpicLatino Neonatal Network (ENN) and described the population of infants with HIE treated and not treated with TH.

METHODS

Data were collected from 2015 to 2022 for patients with HIE. Mortality rates and Sarnat scores were compared before and after TH. The Wilcoxon Signed-Rank Test was used for comparisons.

RESULTS

In this observational study 518 neonates of our total population of 26 970, had HIE (1.92%) of whom 150 underwent TH. Ten out of 21 neonatal intensive care units (NICUs) provided TH. The Wilcoxon Signed Rank Test for 138 cases with complete data showed a significant difference.

CONCLUSION

The findings support the benefits of TH in HIE within this cohort. TH should not be withheld solely due to the economic status of the country. A strict patient selection and TH protocol are essential.

Short-term effects of opioids during therapeutic hypothermia for neonatal encephalopathy

Objective

To examine the effects of opioids during therapeutic hypothermia (TH) on short-term outcomes in neonates with neonatal encephalopathy (NE).

Methods

Multicenter retrospective study of neonates with moderate/severe NE from Jan. 2013-Feb 2021. Opioid exposure was classified as positive (>0.1 mg/kg) or negative (no exposure or ≤0.1 mg/kg) based on cumulative morphine milligram equivalents (MME). Negative binomial regression models were used to evaluate clinical outcomes.

Results

One hundred and twenty neonates were included. Adjusted analyses indicated that opioid exposure was associated with an increase in (1) length of hospitalization, (2) hypotension/use of vasopressors, and (3) need for and longer duration of mechanical ventilation. Many findings persisted even after adjusting for site and the presence of confirmed seizures (a marker of disease severity).

Discussion

Opioid use during TH was associated with adverse effects on short-term outcomes. Caution should be exercised when using opioids during TH until longer-term neurodevelopmental outcome studies can be conducted in larger cohorts.

Safety and tolerability of a Muse cell-based product in neonatal hypoxic-ischemic encephalopathy with therapeutic hypothermia (SHIELD trial)

Hypoxic-ischemic encephalopathy (HIE), associated with high mortality and neurological sequelae, lacks established treatment except therapeutic hypothermia. Clinical-grade multilineage-differentiating stress-enduring (Muse) cells (CL2020) demonstrated safety and efficacy in nonclinical HIE rat models, thereby leading to an investigator-initiated clinical trial to evaluate CL2020 safety and tolerability in neonatal HIE as a single-center open-label dose-escalation study with 9 neonates with moderate-to-severe HIE who received therapeutic hypothermia. Each patient received a single intravenous injection of CL2020 cells between 5 and 14 days of age. The low-dose (3 patients) and high-dose (6 patients) groups received 1.5 × 106 and 1.5 × 107 cells/dose, respectively. The occurrence of any adverse event within 12 weeks following CL2020 administration was the primary endpoint of this trial. No significant changes in physiological signs including heart rate, blood pressure, and oxygen saturation were observed during or after administration. The only adverse event that may be related to cell administration was a mild γ-glutamyltransferase level elevation in one neonate, which spontaneously resolved without any treatment. All patients enrolled in the trial survived, and normal developmental quotients (≥ 85) in all 3 domains of the Kyoto Scale of Psychological Development 2001 were observed in 67% of the patients in this trial. CL2020 administration was demonstrated to be safe and tolerable for neonates with HIE. Considering the small number of patients, a randomized controlled confirmatory study is warranted to verify these preliminary findings and evaluate the efficacy of this therapy.

On target dosing: erythropoietin exposure in neonates with hypoxic-ischemic encephalopathy in the HEAL trial

BACKGROUND

The High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial for neonates with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia demonstrated no neurodevelopmental benefit but was associated with a higher rate of serious adverse events (SAEs). Understanding if targeted Epo plasma exposures were achieved in the HEAL trial and if SAEs were associated with higher exposures would help future therapeutic programs of Epo as a candidate neuroprotective treatment.

METHODS

Ancillary study of a subset of HEAL neonates who received Epo (1000 U/kg IV on days 1, 2, 3, 4, and 7) and had plasma drug concentrations measured. Within a Bayesian pharmacokinetic framework, the area under the curve during the first 48 h (AUC48h) and 7 days (AUC7d) of treatment was estimated. The % of neonates who achieved animal model neuroprotective targets of AUC48h >140,000 mU*h/ml and AUC7d >420,000 mU*h/ml was calculated. The relationship between AUC7d and SAEs after study drug was evaluated using logistic regression.

RESULTS

Among n = 89 neonates, variation in Epo exposure was low, and over 95% of neonates achieved the target AUC48h and AUC7d. No meaningful relationship was seen between AUC7d and risk of SAE.

CONCLUSIONS

The Epo dosing strategy in the HEAL trial consistently achieved target plasma exposures. Higher exposures were not associated with SAEs.

IMPACT

In the HEAL randomized, placebo-controlled trial of high-dose erythropoietin (Epo) for neonates with hypoxic-ischemic encephalopathy (HIE) receiving therapeutic hypothermia, the Epo dosing strategy achieved animal model neuroprotective plasma exposure targets in >95% of neonates. This understanding further strengthens the HEAL trial's primary conclusion that Epo provides no additional benefit in neonates with HIE also receiving therapeutic hypothermia. While Epo treatment was associated with a higher rate of serious adverse events (SAEs) compared to placebo in the primary HEAL trial, higher plasma exposures of Epo were not associated with the risk of SAEs.