Cooling neonates who do not fulfil the standard cooling criteria - short- and long-term outcomes

Protocol for a magnetic resonance imaging study of participants in the fever RCT: Does fever control prevent brain injury in malaria?

BACKGROUND

Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy.

METHODS

This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury.

DISCUSSION

Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Protocol for a Magnetic Resonance Imaging (MRI) Study of Participants in the Fever Randomized Controlled Trial: Does fever control prevent brain injury in malaria?

Background

Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy.

Methods

This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury.

Discussion

Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

Sudden Unexpected Postnatal Collapse and Therapeutic Hypothermia: What's Going On?

Sudden unexpected postnatal collapse (SUPC) is a rare event, potentially associated with catastrophic consequences. Since the beginning of the 2000s, therapeutic hypothermia (TH) has been proposed as a treatment for asphyxiated neonates after SUPC. However, only a few studies have reported the outcome of SUPC after TH. The current study presents the long-term neurodevelopmental outcome of four cases of SUPC treated with TH in a single Italian center. Furthermore, we reviewed the previous literature concerning 49 cases of SUPC treated with TH. Among 53 total cases (of whom four occurred in our center), 15 (28.3%) died before discharge from the NICU. A neurodevelopmental follow-up was available only for 21 (55.3%) out of the 38 surviving cases, and seven infants developed neurodevelopmental sequelae. TH should be considered in neonates with asphyxia after SUPC. However, SUPC is a rare event, and there is a lack of comparative clinical data to establish the risk/benefit of TH after SUPC with different degrees of asphyxia. Analysis of large cohorts of newborns with SUPC, whether treated with TH or untreated, are needed in order to better identify infants who should undergo TH.

Challenges in the application of non-servocontrolled therapeutic hypothermia during neonatal transport in Catalonia

INTRODUCTION

Therapeutic hypothermia (TH) improves survival and neurological prognosis in hypoxic-ischemic encephalopathic (HIE) babies, being better the sooner TH is implemented. HIE babies are born more frequently in a non-cooling centre and need to be referred.

METHODS

Prospective-observational study (April 18 2018 - November 19 2019). Newborns (≥34 weeks of gestational age (GA) and >1800 g) with moderate/severe HIE on non-servocontrolled therapeutic hypothermia by the two neonatal transport teams in Catalonia.

RESULTS

51 newborns. The median stabilisation and transport time were 68 min (p25-75, 45-85 min) and 30 min (p25-75, 15-45 min), respectively. The mean age at arrival at the receiving unit was 4 h and 18 min (SD 96.6). The incubator was set off in 43 (84%), iced-packs 11 (21.5%) and both (11, 21.5%). Target temperature was reached in 19 (37.3%) babies. There were no differences in the overcooling in relation to the measures applied. The transport duration was not related with temperature stabilisation or target temperature reachiness.

CONCLUSIONS

Rectal temperature monitorisation is compulsory for the stabilisation and the application of non-servocontrolled hypothermia during transport. There is still time for improving in the administration of this treatment during transport. Servo-controlled hypothermia would be a better alternative to improve the management of HIE babies.

[Challenges in the application of non-servocontrolled therapeutic hypothermia during neonatal transport in Catalonia]

INTRODUCTION

Therapeutic hypothermia (TH) improves survival and neurological prognosis in hypoxic-ischemic encephalopathic (HIE) babies, being better the sooner TH is implemented. HIE babies are born more frequently in a non-cooling centre and need to be referred.

METHODS

Prospective-observational study (April 18-November 19). Newborns (≥34 weeks of gestational age (GA) and >1800g) with moderate/severe HIE on non-servocontrolled therapeutic hypothermia by the two neonatal transport teams in Catalonia.

RESULTS

51 newborns. The median stabilisation and transport time were 68min (p25-75, 45-85min) and 30min (p25-75, 15-45min), respectively. The mean age at arrival at the receiving unit was 4h and 18min (SD 96.6). The incubator was set off in 43 (84%), iced-packs 11 (21.5%) and both (11, 21.5%). Target temperature was reached in 19 (37.3%) babies. There was no differences in the overcooling in relation to the measures applied. The transport duration was not related with temperature stabilisation or target temperature reachiness.

CONCLUSIONS

Rectal temperature monitorisation is compulsory for the stabilisation and the application of non-servocontrolled hypothermia during transport. There is still time for improving in the administration of this treatment during transport. Servo-controlled hypothermia would be a better alternative to improve the management of HIE babies.

Morphine and fentanyl exposure during therapeutic hypothermia does not impair neurodevelopment

BACKGROUND

Hypothermia-treated and intubated infants with moderate or severe hypoxic-ischemic encephalopathy (HIE) usually receive morphine for sedation and analgesia (SA) during therapeutic hypothermia (TH) and endotracheal ventilation. Altered drug pharmacokinetics in this population increases the risk of drug accumulation. Opioids are neurotoxic in preterm infants. In term infants undergoing TH, the long-term effects of morphine exposure are unknown. We examined the effect of opioid administration during TH on neurodevelopmental outcome and time to extubation after sedation ended.

METHODS

In this prospectively collected population-based cohort of 282 infants with HIE treated with TH (2007-2017), the cumulative opioid dose of morphine and equipotent fentanyl (10-60 µg/kg/h) administered during the first week of life was calculated. Clinical outcomes and concomitant medications were also collected. Of 258 survivors, 229 underwent Bayley-3 neurodevelopmental assessments of cognition, language and motor function at 18-24 months. Multivariate stepwise linear regression analysis was used to examine the relation between cumulative opioid dose and Bayley-3 scores. Three severity-groups (mild-moderate-severe) were stratified by early (<6 h) amplitude-integrated electroencephalography (aEEG) patterns.

FINDINGS

The cumulative dose of opioid administered as SA during TH was median (IQR) 2121 µg/kg (1343, 2741). Time to extubation was independent of SA dose (p > 0.2). There was no significant association between cumulative SA dose and any of the Bayley-3 domains when analysing the entire cohort or any of the aEEG severity groups.

INTERPRETATION

Higher cumulative opioid doses in TH-treated infants with HIE was not associated with worse Bayley-3 scores at 18-24 months of age.

FUNDING

The Bristol cooling program was funded by the Children's Medical Research Charity SPARKS managing donations for our research from the UK and US, the UK Moulton Foundation, the Lærdal Foundation for Acute Medicine in Norway and the Norwegian Research Council (JKG).

MRI combined with early clinical variables are excellent outcome predictors for newborn infants undergoing therapeutic hypothermia after perinatal asphyxia

BACKGROUND

Binary prediction-models for outcome [death, cognition, presence and severity of cerebral palsy (CP)], using MRI and early clinical data applicable for individual outcome prediction have not been developed.

METHODS

From Dec 1st 2006 until Dec 31st 2013, we recruited 178 infants into a population-based cohort with moderate or severe hypoxic-ischaemic encephalopathy (HIE) including postnatal collapse (PNC, n = 12) and additional diagnoses (n = 12) using CoolCap/TOBY-trial entry-criteria including depressed amplitude-integrated EEG (aEEG). Early clinical/biochemical variables and MRI scans (median day 8) were obtained in 168 infants. Injury severity was scored for cortex, basal ganglia/thalami (BGT), white matter (WM) and posterior limb of the internal capsule, summating to a total injury score (TIS, range 0-11). Outcome was categorized as adverse or favourable at 18-24 months from Bayley-III domains (cut-off 85) and neurological examination including CP classification.

FINDINGS

HIE and entry-aEEG severity were stable throughout the study. Outcome was favourable in 133/178 infants and adverse in 45/178: 17 died, 28 had low Cognition/Language scores, (including 9 with severe CP and 6 mild); seven had mild CP with favourable cognitive outcome. WMxBGT product scores and TIS were strong outcome predictors, and prediction improved when clinical/biochemical variables were added in binary logistic regression. The Positive Predictive Value for adverse outcome was 88%, increasing to 95% after excluding infants with PNC and additional diagnoses. Using WMxBGT in the regression predicted 8 of the 9 children with severe CP.

INTERPRETATION

Binary logistic regression with WMxBGT or TIS and clinical variables gave excellent outcome prediction being 12% better than single variable cross-tabulation. Our MRI scoring and regression models are readily accessible and deserve investigation in other cohorts for group and individual prediction.

FUNDING

We thank the National Health Service (NHS) and our Universities and funders in UK and Norway: SPARKS, The Moulton Foundation, The Norwegian Research Council, The Lærdal Foundation for Acute Medicine and charitable donations for their support for cooling therapy.

Emerging therapies and management for neonatal encephalopathy-controversies and current approaches

Neonatal encephalopathy (NE) continues to have a major impact on newborn survival and neurodevelopmental outcomes worldwide. In high-income settings, therapeutic hypothermia is the only established standard treatment for neonates with moderate-to-severe NE, with compelling evidence that cooling reduces mortality and major neurodevelopmental impairment in survivors. Despite therapeutic hypothermia, a significant proportion of cooled infants continue to suffer long-term disability from brain injury. Innovative therapies offer the possibility of further improving neurodevelopmental outcomes by working synergistically with therapeutic hypothermia to decrease hypoxia-ischemia-induced excitotoxicity, prevent progression to secondary energy failure, and in some cases, promote neuroregeneration in the developing neonatal brain. This review discusses emerging NE therapies currently under investigation, offers insight into controversies surrounding various approaches to clinical care during therapeutic hypothermia, and identifies ongoing knowledge deficits that hinder attainment of optimal outcomes for neonates with NE.

Therapeutic hypothermia and outcome in hyponatraemic encephalopathy secondary to maternal water intoxication

Misguided encouragement to consume large volumes of water during labour for pain relief results in dilutional hyponatraemia in mothers and their babies presenting with neurological dysfunction. We report three babies who were encephalopathic with seizures in the background of hyponatraemia secondary to maternal ingestion of large volumes of water and mild perinatal asphyxia. All babies underwent therapeutic hypothermia in addition to sodium supplementation with fluid restriction. Their neurodevelopment was appropriate for age. This case series highlights the dilemma that could arise with hyponatraemic encephalopathy and mild perinatal asphyxia in the first 6 hours of life, which is the window of opportunity for therapeutic hypothermia for hypoxic-ischaemic encephalopathy. It is important to educate pregnant mothers in labour on the adverse effects of excessive fluid ingestion.

[Sudden unexpected postnatal collapse in a neonate]

A healthy full-term female neonate, aged 3 days and born by vaginal delivery (with a 1-minute Apgar score of 10 and a 5-minute Apgar score of 10), had unexpected cardiac and respiratory arrests in the early morning on day 3 after birth and recovered to spontaneous breathing and heartbeat after a 10-minute resuscitation. The child had poor response and convulsion after resuscitation. Blood gas analysis showed metabolic acidosis, and amplitude-integrated EEG showed a burst-suppression pattern. She was diagnosed with sudden unexpected postnatal collapse but improved after hypothermia and symptomatic/supportive treatment. This article reports the first case of sudden unexpected postnatal collapse in China and summarizes related risk factors, pathophysiological mechanisms, and preventive and treatment measures of this disorder.

Acute symptomatic neonatal seizures, brain injury, and long-term outcome: The role of neuroprotective strategies

INTRODUCTION

Neonatal seizures are frequent but underdiagnosed manifestations of acute brain dysfunction and an important contributor to unfavorable outcomes. Etiology and severity of brain injury are the single strongest outcome determinants.

AREAS COVERED

The authors will discuss the prognostic role of acute symptomatic seizures versus brain injury and the main neuroprotective and neurorestorative strategies for full-term and preterm infants.

EXPERT OPINION

Prolonged acute symptomatic seizures likely contribute to long-term outcomes by independently adding further brain injury to initial insults. Correct timing and dosing of therapeutic interventions, depending on etiology and gestational ages, need careful evaluation. Although promising strategies are under study, the only standard of care is whole-body therapeutic hypothermia in full-term newborns with hypoxic-ischemic encephalopathy.

Ten years since the introduction of therapeutic hypothermia in neonates with perinatal hypoxic-ischaemic encephalopathy in Spain

INTRODUCTION

More than a decade has passed since therapeutic hypothermia (TH) was introduced in Spain; this is the only neuroprotective intervention that has become standard practice in the treatment of perinatal hypoxic-ischaemic encephalopathy (HIE). This article aims to provide a current picture of the technique and to address the controversies surrounding its use.

DEVELOPMENT

In the last 10 years, TH has been successfully implemented in the vast majority of tertiary hospitals in Spain, and more than 85% of newborns with moderate or severe HIE currently receive the treatment. The factors that can improve the efficacy of TH include early treatment onset (first 6hours of life) and the control of comorbid factors associated with perinatal asphyxia. In patients with moderate HIE, treatment onset after 6hours seems to have some neuroprotective efficacy. TH duration longer than 72hours or deeper hypothermia do not offer greater neuroprotective efficacy, but instead increase the risk of adverse effects. Unclarified aspects are the sedation of patients during TH, the application of the treatment in infants with mild HIE, and its application in other scenarios. Prognostic information and time frame are one of the most challenging aspects.

CONCLUSIONS

TH is universal in countries with sufficient economic resources, although certain unresolved controversies remain. While the treatment is widespread in Spain, there is a need for cooling devices for the transfer of these patients and their centralisation.

Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key

With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.

Clinical application of target temperature management in children with acute encephalopathy-A practical review

Acute encephalopathy is a life-threatening disease involving acute brain dysfunction, and it is one of the most important causes of mortality and severe neurological sequelae in infants and children. Approximately 30% of cases of acute encephalopathy result in some degree of neurological sequelae. Although many strategies have been proposed, effective therapies to ameliorate the outcomes of acute encephalopathy have not yet been established. Target temperature management (TTM), previously termed therapeutic hypothermia, has been shown to be effective for various brain injuries due to multiple neuroprotective mechanisms, and it may be considered to be the cornerstone of neuroprotective strategies. Consequently, TTM is currently used in the neurocritical care of adult patients with cardiac arrest with shockable rhythm and perinatal asphyxia. In addition, increasing evidence also indicates that TTM could be useful in other acute encephalopathies, including status epilepticus, acute encephalitis/encephalopathy and traumatic brain injury. In this review, we discuss the recent practical aspects of TTM as a potential intervention for various acute encephalopathies in children.

Two-Year Neurodevelopmental Outcomes After Mild Hypoxic Ischemic Encephalopathy in the Era of Therapeutic Hypothermia

IMPORTANCE

Therapeutic hypothermia reduces risk of death and disability in infants with moderate to severe hypoxic ischemic encephalopathy (HIE). Randomized clinical trials of therapeutic hypothermia to date have not included infants with mild HIE because of a perceived good prognosis.

OBJECTIVE

To test the hypothesis that children with mild HIE have worse neurodevelopmental outcomes than their healthy peers.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of pooled data from 4 prospective cohort studies in Cork, Ireland, and Stockholm, Sweden, between January 2007 and August 2015. The dates of data analysis were September 2017 to June 2019. Follow-up was performed at age 18 to 42 months. In this multicenter cohort study, all children were born or treated at the tertiary centers of Cork University Maternity Hospital, Cork, Ireland, or Karolinska University Hospital, Stockholm, Sweden. In all, 690 children were eligible for this study.

EXPOSURES

At discharge, all children were categorized into the following 5 groups using a modified Sarnat score: healthy controls, perinatal asphyxia (PA) without HIE, mild HIE, moderate HIE, and severe HIE.

MAIN OUTCOMES AND MEASURES

Cognitive, language, and motor development were assessed with the Bayley Scales of Infant and Toddler Development, Third Edition (BSITD-III). The BSITD-III scores are standardized to a mean (SD) of 100 (15), with lower scores indicating risk of developmental delay.

RESULTS

Of the 690 children eligible for this study, 2-year follow-up data were available in 471 (mean [SD] age at follow-up, 25.6 [5.7] months; 54.8% male), including 152 controls, 185 children with PA without HIE, and 134 children with HIE, of whom 14 had died. Infants with mild HIE (n = 55) had lower cognitive composite scores compared with controls, with a mean (SD) of 97.6 (11.9) vs 103.6 (14.6); the crude mean difference was -6.0 (95% CI, -9.9 to -2.1), and the adjusted mean difference was -5.2 (95% CI, -9.1 to -1.3). There was no significant difference in the mean cognitive composite scores between untreated children (n = 47) with mild HIE and surviving children with moderate HIE (n = 53) treated with therapeutic hypothermia, with a crude mean difference for mild vs moderate of -2.2 (95% CI, -8.1 to 3.7).

CONCLUSIONS AND RELEVANCE

This study's findings suggest that, at age 2 years, the cognitive composite scores of children with a history of mild HIE may be lower than those of a contemporaneous control group and may not be significantly different from those of survivors of moderate HIE treated with therapeutic hypothermia.

Prevention of excessive hypothermia in infants with hypoxic ischemic encephalopathy prior to admission to a quaternary care center: a neonatal outreach educational project

OBJECTIVE

Excessive hypothermia is common in infants that receive passive cooling for hypoxic ischemic encephalopathy (HIE). Our goal was to reduce the number of infants with admission temperature <33 °C from 33% to less than 10% by December 2017.

METHODS

Outcome measures included the number of infants with admission temperature <33 °C and number of infants with temperature within therapeutic range. Interventions included implementation of passive cooling guidelines and outreach education to birth hospitals and transport team. We used statistical process control chart to compare outcomes over a 3 year period.

RESULTS

The number of infants with admission temperature <33 °C decreased from 33.3% to 5.5% (p = 0.013). The number of infants with admission temperature within target range for hypothermia therapy increased from 61.1% to 77.7% (p = 0.014). Balancing measures and complications remained unchanged.

CONCLUSION

Implementation of passive cooling guidelines and outreach education led to significant decrease in excessive hypothermia in infants with HIE.

Motor performance and cognitive correlates in children cooled for neonatal encephalopathy without cerebral palsy at school age

AIM

To investigate whether motor performance in school-age children without cerebral palsy (CP), cooled for neonatal encephalopathy, is associated with perinatal factors and 18-month developmental scores and to explore relationships between school-age motor and cognitive performance.

METHODS

Motor and cognitive performance was assessed in 29 previously cooled children at six to eight years using the Movement Assessment Battery for Children-2 (MABC-2) and the Wechsler Intelligence Scale for Children (WISC-IV). Associations between MABC-2 scores less than/equal (≤) 15th centile and perinatal factors, social/family background, 18-month Bayley-III scores and WISC-IV scores were explored.

RESULTS

Eleven of the 29 (38%) children had MABC-2 scores ≤15th centile including 7 (24%) ≤5th centile. No significant perinatal or socio-economic risk factors were identified. Motor scores <85 at 18 months failed to identify children with MABC-2 scores ≤15th centile. MABC-2 scores ≤15th centile were associated with lower Full Scale IQ (p = 0.045), Working Memory (p = 0.03) and Perceptual Reasoning (p = 0.005) scores at six to eight years and receiving greater support in school (p = 0.01).

CONCLUSION

A third of cooled children without CP had MABC-2 scores indicating motor impairment at school age that was not identified at 18 months by Bayley-III. Most children with low MABC scores needed support at school. Sub-optimal MABC-2 scores indicate need for detailed school-age cognitive evaluation.

Sudden unexpected postnatal collapse

This review of Sudden Unexpected Postnatal Collapse (SUPC) highlights the challenges in definition and nomenclature that currently exist. In comparing SUPC with Sudden Unexpected Death in Infancy (SUDI), the potentially avoidable nature of many SUPC is emphasised and the role of positioning and public awareness explored. The article focusses on the implementation of preventative strategies in the immediate postnatal period and the role of therapeutic hypothermia in ameliorating long term neurological injury.

Hypothermia for newborns with hypoxic-ischemic encephalopathy

Therapeutic hypothermia is a standard of care for infants ≥36 weeks gestational age (GA) with moderate-to-severe hypoxic-ischemic encephalopathy. Because some studies included infants born at 35 weeks GA, hypothermia should be considered if they meet other criteria. Cooling for infants <35 weeks GA is not recommended. Passive cooling should be started promptly in community centres, in consultation with a tertiary care centre neonatologist, while closely monitoring the infant's temperature. Best evidence suggests that maintaining core body temperature between 33°C and 34°C for 72 hours, followed by a period of rewarming of 6 to 12 hours, is optimal. Antiepileptic medications should be used when clinical or electrographic seizures are present. Maintaining serum electrolytes and glucose within normal ranges, and avoiding hypo- or hypercarbia and hyperoxia, are important adjunct treatments. A brain magnetic resonance image (MRI) is advised shortly after rewarming and, in cases where earlier findings do not match the clinical picture, a repeat MRI after 10 days of life is suggested. Multidisciplinary neurodevelopmental follow-up is recommended.

Neonatal therapeutic hypothermia outside of standard guidelines: a survey of U.S. neonatologists

AIM

Therapeutic hypothermia is standard of care in term infants with moderate-to-severe hypoxic-ischaemic encephalopathy (HIE). The goal of this survey was to explore the attitudes of U.S. neonatologists caring for infants with HIE who fall outside of current guidelines.

METHODS

Case-based survey administered to members of the Section on Neonatal-Perinatal Medicine of the American Academy of Pediatrics.

RESULTS

A total of 447 responses were analysed, a response rate of 19%. We found significant variability amongst U.S. neonatologists with regard to the use of therapeutic hypothermia for infants with HIE who fall outside standard inclusion criteria. Scenarios with the most variability included HIE in a late preterm infant and HIE following a postnatal code. Provision of therapeutic hypothermia outside of standard guidelines was not influenced by number of years in practice, neonatal intensive care type (NICU) or NICU size.

CONCLUSION

Significant variability in practice exists when caring for infants with HIE who do not meet standard inclusion criteria, emphasizing the need for continued and rigorous research in this area.

Effect of Therapeutic Hypothermia Initiated After 6 Hours of Age on Death or Disability Among Newborns With Hypoxic-Ischemic Encephalopathy: A Randomized Clinical Trial

Importance

Hypothermia initiated at less than 6 hours after birth reduces death or disability for infants with hypoxic-ischemic encephalopathy at 36 weeks' or later gestation. To our knowledge, hypothermia trials have not been performed in infants presenting after 6 hours.

Objective

To estimate the probability that hypothermia initiated at 6 to 24 hours after birth reduces the risk of death or disability at 18 months among infants with hypoxic-ischemic encephalopathy.

Design, Setting, and Participants

A randomized clinical trial was conducted between April 2008 and June 2016 among infants at 36 weeks' or later gestation with moderate or severe hypoxic-ischemic encephalopathy enrolled at 6 to 24 hours after birth. Twenty-one US Neonatal Research Network centers participated. Bayesian analyses were prespecified given the anticipated limited sample size.

Interventions

Targeted esophageal temperature was used in 168 infants. Eighty-three hypothermic infants were maintained at 33.5°C (acceptable range, 33°C-34°C) for 96 hours and then rewarmed. Eighty-five noncooled infants were maintained at 37.0°C (acceptable range, 36.5°C-37.3°C).

Main Outcomes and Measures

The composite of death or disability (moderate or severe) at 18 to 22 months adjusted for level of encephalopathy and age at randomization.

Results

Hypothermic and noncooled infants were term (mean [SD], 39 [2] and 39 [1] weeks' gestation, respectively), and 47 of 83 (57%) and 55 of 85 (65%) were male, respectively. Both groups were acidemic at birth, predominantly transferred to the treating center with moderate encephalopathy, and were randomized at a mean (SD) of 16 (5) and 15 (5) hours for hypothermic and noncooled groups, respectively. The primary outcome occurred in 19 of 78 hypothermic infants (24.4%) and 22 of 79 noncooled infants (27.9%) (absolute difference, 3.5%; 95% CI, -1% to 17%). Bayesian analysis using a neutral prior indicated a 76% posterior probability of reduced death or disability with hypothermia relative to the noncooled group (adjusted posterior risk ratio, 0.86; 95% credible interval, 0.58-1.29). The probability that death or disability in cooled infants was at least 1%, 2%, or 3% less than noncooled infants was 71%, 64%, and 56%, respectively.

Conclusions and Relevance

Among term infants with hypoxic-ischemic encephalopathy, hypothermia initiated at 6 to 24 hours after birth compared with noncooling resulted in a 76% probability of any reduction in death or disability, and a 64% probability of at least 2% less death or disability at 18 to 22 months. Hypothermia initiated at 6 to 24 hours after birth may have benefit but there is uncertainty in its effectiveness.

Trial Registration

clinicaltrials.gov Identifier: NCT00614744.

Reduced infancy and childhood epilepsy following hypothermia-treated neonatal encephalopathy

OBJECTIVE

To investigate what proportion of a regional cohort of cooled infants with neonatal encephalopathy develop epilepsy (determined by the International League Against Epilepsy [ILAE] definition and the number of antiepileptic drugs [AEDs]) up to 8 years of age.

METHODS

From 2006-2013, 151 infants with perinatal asphyxia underwent 72 h cooling. Clinical and amplitude-integrated electroencepalography (aEEG) with single-channel EEG-verified neonatal seizures were treated with AEDs. Brain magnetic resonance imaging (MRI) was assessed using a 0-11 severity score. Postneonatal seizures, epilepsy rates, and AED treatments were documented. One hundred thirty-four survivors were assessed at 18-24 months; adverse outcome was defined as death or Bayley III composite Cognition/Language or Motor scores <85 and/or severe cerebral palsy or severely reduced vision/hearing. Epilepsy rates in 103 children age 4-8 years were also documented.

RESULTS

aEEG confirmed seizures occurred precooling in 77 (57%) 151 of neonates; 48% had seizures during and/or after cooling and received AEDs. Only one infant was discharged on AEDs. At 18-24 months, one third of infants had an adverse outcome including 11% mortality. At 2 years, 8 (6%) infants had an epilepsy diagnosis (ILAE definition), of whom 3 (2%) received AEDs. Of the 103 4- to 8-year-olds, 14 (13%) had developed epilepsy, with 7 (7%) receiving AEDs. Infants/children on AEDs had higher MRI scores than those not on AEDs (median [interquartile range] 9 [8-11] vs. 2 [0-4]) and poorer outcomes. Nine (64%) of 14 children with epilepsy had cerebral palsy compared to 13 (11%) of 120 without epilepsy, and 10 (71%) of 14 children with epilepsy had adverse outcomes versus 23 (19%) of 120 survivors without epilepsy. The number of different AEDs given to control neonatal seizures, aEEG severity precooling, and MRI scores predicted childhood epilepsy.

SIGNIFICANCE

We report, in a regional cohort of infants cooled for perinatal asphyxia, 6% with epilepsy at 2 years (2% on AEDs) increasing to 13% (7% on AEDs) at early school age. These AED rates are much lower than those reported in the cooling trials, even with adjusting for our cohort's milder asphyxia. Long-term follow-up is needed to document final epilepsy rates.

Neonatal Encephalopathy: Update on Therapeutic Hypothermia and Other Novel Therapeutics

Neonatal encephalopathy (NE) is a major cause of neonatal mortality and morbidity. Therapeutic hypothermia (TH) is standard treatment for newborns at 36 weeks of gestation or greater with intrapartum hypoxia-related NE. Term and late preterm infants with moderate to severe encephalopathy show improved survival and neurodevelopmental outcomes at 18 months of age after TH. TH can increase survival without increasing major disability, rates of an IQ less than 70, or cerebral palsy. Neonates with severe NE remain at risk of death or severe neurodevelopmental impairment. This review discusses the evidence supporting TH for term or near term neonates with NE.

Birth Asphyxia and Hypoxic-Ischemic Brain Injury in the Preterm Infant

Birth asphyxia, also termed perinatal hypoxia-ischemia, is a modifiable condition as evidenced by improved outcomes of infants ≥36 weeks' gestation provided hypothermia treatment in randomized trials. Preterm animal models of asphyxia in utero demonstrate that hypothermia can provide short-term neuroprotection for the developing brain, supporting the interest in extending therapeutic hypothermia to preterm infants. This review focuses on the challenge of identifying preterm infants with perinatal asphyxia; the neuropathology of hypoxic-ischemic brain injury across extreme, moderate, and late preterm infants; and patterns of brain injury, use of therapeutic hypothermia, and approach to patient selection for neuroprotective treatments among preterm infants.