Outcomes of neonatal hypoxic-ischaemic encephalopathy in centres with and without active therapeutic hypothermia: a nationwide propensity score-matched analysis

[Investigation of a French cohort of neonatal anoxo-ischemic encephalopathy in the era of therapeutic hypothermia: Questions and answers]

OBJECTIVE

To improve knowledge of neonatal hypoxic-ischemic encephalopathy, a prospective, nationwide, population-based cohort of affected children is being set up between September 2015 and March 2017.

METHODS

During this period, 794 cases are collected, with information on pregnancy, delivery, neonatal stay and outcome at the end of hospitalization. Clinical and parental questionnaire follow-up is planned until the child is 4 years old.

RESULTS

This article presents the clinical presentation of the newborns included, the analysis of factors associated with short-term outcome at hospital discharge and the organizational factors associated with treatment with therapeutic hypothermia.

CONCLUSION

These data illustrate the value of a prospective cohort to analyze the management of anoxo-ischemic encephalopathy in France.

The future of artificial hibernation medicine: protection of nerves and organs after spinal cord injury

Spinal cord injury is a serious disease of the central nervous system involving irreversible nerve injury and various organ system injuries. At present, no effective clinical treatment exists. As one of the artificial hibernation techniques, mild hypothermia has preliminarily confirmed its clinical effect on spinal cord injury. However, its technical defects and barriers, along with serious clinical side effects, restrict its clinical application for spinal cord injury. Artificial hibernation is a future-oriented disruptive technology for human life support. It involves endogenous hibernation inducers and hibernation-related central neuromodulation that activate particular neurons, reduce the central constant temperature setting point, disrupt the normal constant body temperature, make the body "adapt" to the external cold environment, and reduce the physiological resistance to cold stimulation. Thus, studying the artificial hibernation mechanism may help develop new treatment strategies more suitable for clinical use than the cooling method of mild hypothermia technology. This review introduces artificial hibernation technologies, including mild hypothermia technology, hibernation inducers, and hibernation-related central neuromodulation technology. It summarizes the relevant research on hypothermia and hibernation for organ and nerve protection. These studies show that artificial hibernation technologies have therapeutic significance on nerve injury after spinal cord injury through inflammatory inhibition, immunosuppression, oxidative defense, and possible central protection. It also promotes the repair and protection of respiratory and digestive, cardiovascular, locomotor, urinary, and endocrine systems. This review provides new insights for the clinical treatment of nerve and multiple organ protection after spinal cord injury thanks to artificial hibernation. At present, artificial hibernation technology is not mature, and research faces various challenges. Nevertheless, the effort is worthwhile for the future development of medicine.

The critical role of technologies in neonatal care

Neonatal care has made significant advances in the last few decades. As a result, mortality and morbidity in high-risk infants, such as extremely preterm infants or those infants with birth-related brain injury, has reduced significantly. Many of these advances have been facilitated or delivered through development of medical technologies allowing clinical teams to be better supported with the care they deliver or provide new therapies and diagnostics to improve management. The delivery of neonatal intensive care requires the provision of medical technologies that are easy to use, reliable, accurate and ideally developed for the unique needs of the newborn population. Many technologies have been developed and commercialised following adult trials without ever being studied in neonatal patients despite the unique characteristics of this population. Increasingly, funders and industry are recognising this major challenge which has resulted in initiatives to develop new ideas from concept through to clinical care. This review explores some of the key medical technologies used in neonatal care and the evidence to support their adoption to improve outcomes. A number of devices have yet to realise their full potential and will require further development to optimise and find their ideal target population and clinical benefit. Examples of emerging technologies, which may soon become more widely used, are also discussed. As neonatal care relies more on medical technologies, we need to be aware of the impact on care pathways, especially from a human factors approach, the associated costs and subsequent benefits to patients alongside the supporting evidence.

Early-Life Epilepsies

Epilepsies are a diverse group of neurological disorders characterized by recurrent seizures. One-third of epilepsies are refractory to standard antiseizure medications. Epilepsy incidence is age-dependent with high incidence in neonates and infants. Epilepsy syndromes are classified based on clinical, electrographic, neuroimaging, age-dependent features of onset and the possibility of remission. Advances in genetic testing technology and improved access to clinical genetic testing, including whole exome sequencing, have facilitated a fundamental shift in gene discovery of monogenetic and polygenetic epilepsy, leading to precision medicine therapy and improved outcomes. Here, we review the self-limited epilepsy syndromes and developmental and epileptic encephalopathies that begin in the neonatal-infantile period with an emphasis on genetic etiology and the shifting landscape of treatment options based on genetic findings. [Pediatr Ann. 2023;52(10):e381-e387.].

Neurosteroid pathway derangement in asphyctic infants treated with hypothermia: an untargeted metabolomic approach

BACKGROUND

The pathobiological mechanisms associated with perinatal asphyxia and hypoxic-ischemic encephalopathy are complex and poorly understood. The metabolic effects of therapeutic hypothermia have been partially explored.

METHODS

We conducted a single-center longitudinal study to investigate the metabolic effects of perinatal asphyxia and hypoxic-ischemic encephalopathy on the urinary metabolome of a group of 12 asphyctic infants over time compared to 22 matched healthy newborns, using untargeted metabolomics based on mass spectrometry.

FINDINGS

Over-representation pathway analysis identified the steroidogenesis pathway as being significantly disrupted, with reduced steroid levels in the first three days of life despite treatment with hypothermia. Comparison with matched healthy newborns showed that the urinary steroid content was lower in asphyctic infants before hypothermia. The lysine degradation and carnitine synthesis pathways were also significantly affected.

INTERPRETATION

Steroidogenesis is significantly disrupted in asphyctic infants compared to healthy newborns. Given how neurosteroids are involved in neuromodulation and neuroprotection, translational research is warranted on the potential role of neurosteroid-based intervention in asphyctic infants.

FUNDING

None.

Depth of anesthesia, temperature, and postoperative delirium in children and adolescents undergoing cardiac surgery

BACKGROUND

After pediatric cardiosurgical interventions, postoperative delirium can occur, which can be associated with undesirable consequences during and after the hospital stay. It is therefore important to avoid any factors causing delirium as far as possible. Electroencephalogram (EEG) monitoring can be used during anesthesia to individually adjust dosages of hypnotically acting drugs. It is necessary to gain knowledge about the relationship between intraoperative EEG and postoperative delirium in children.

METHODS

In a dataset comprising 89 children (53 male, 36 female; median age: 0.99 (interquartile range: 0.51, 4.89) years) undergoing cardiac surgery involving use of a heart-lung machine, relationships between depth of anesthesia as measured by EEG (EEG index: Narcotrend Index (NI)), sevoflurane dosage, and body temperature were analyzed. A Cornell Assessment of Pediatric Delirium (CAP-D) score ≥ 9 indicated delirium.

RESULTS

The EEG could be used in patients of all age groups for patient monitoring during anesthesia. In the context of induced hypothermia, EEG monitoring supported individually adjusted sevoflurane dosing. The NI was significantly correlated with the body temperature; decreasing temperature was accompanied by a decreasing NI. A CAP-D score ≥ 9 was documented in 61 patients (68.5%); 28 patients (31.5%) had a CAP-D < 9. Delirious patients with an intubation time ≤ 24 h showed a moderate negative correlation between minimum NI (NImin) and CAP-D (rho = -0.41, 95% CI: -0.70 - -0.01, p = 0.046), i.e., CAP-D decreased with increasing NImin. In the analysis of all patients' data, NImin and CAP-D showed a weak negative correlation (rho = -0.21, 95% CI: -0.40 - 0.01, p = 0.064). On average, the youngest patients had the highest CAP-D scores (p = 0.002). Patients with burst suppression / suppression EEG had a longer median intubation time in the intensive care unit than patients without such EEG (p = 0.023). There was no relationship between minimum temperature and CAP-D score.

CONCLUSIONS

The EEG can be used to individually adjust sevoflurane dosing during hypothermia. Of the patients extubated within 24 h and classified as delirious, patients with deeper levels of anesthesia had more severe delirium symptoms than patients with lighter levels of anesthesia.

Healthcare organizational factors associated with delayed therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy: the LyTONEPAL cohort

Initiation of therapeutic hypothermia (TH) within 6 h of life is a major concern for treating neonatal hypoxic ischemic encephalopathy (HIE). We aimed to determine clinical and healthcare organizational factors associated with delayed TH in a French population-based cohort of neonates with moderate/severe HIE. Time to reach a rectal temperature of 34 °C defines optimal and delayed (within and over 6 h, respectively) TH. Clinical and healthcare organizational factors associated with delayed TH were analysed among neonates born in cooling centres (CCs) and non-cooling centres (non-CCs). Among 629 neonates eligible for TH, 574 received treatment (91.3%). TH was delayed in 29.8% neonates and in 20.3% and 36.2% of those born in CCs and non-CCs, respectively. Neonates with moderate HIE were more exposed to delayed TH in both CCs and non-CCs. After adjustment for HIE severity, maternal and neonatal characteristics and circumstances of birth were not associated with increased risk of delayed TH. However, this risk was 2 to 5 times higher in maternities with < 1999 annual births, when the delay between birth and call for transfer (adjusted odds ratio [aOR] 2.47, 95% confidence interval [CI] [1.03 to 5.96]) or between call for transfer and admission (aOR 6.06, 95%CI [2.60 to 14.12]) was > 3 h and when an undesirable event occurred during transfer (aOR 2.66, 95%CI [1.11 to 6.37].  Conclusion: Increasing early identification of neonates who could benefit from TH and access to TH in non-CCs before transfer are modifiable factors that could improve care of neonates with HIE.  Trial registration: The trial was registered at ClinicalTrials.gov (NCT02676063). What is Known: • International recommendations are to initiate therapeutic hypothermia before 6 h of life in neonates with moderate or severe hypoxic ischemic encephalopathy. What is New: •In this French population-based cohort of infants with hypoxic ischemic encephalopathy, nearly one-third of neonates eligible for treatment did not have access to hypothermia in the therapeutic window of 6 h of life. . • Among infants born in non-cooling centres, healthcare organizational factors involved in delayed care were the small size of maternities (1999 annual births), a time interval of more than 3 h between birth and call for transfer and between call for transfer and admission in neonatology, and the occurrence of an undesirable event during transfer.

Clinical practice guidelines for neonatal hypoxic-ischemic encephalopathy: A systematic review using the appraisal of guidelines for research and evaluation (AGREE) II instrument

Background and Objective

To systematically review, critically appraise the quality of recent clinical practice guidelines (CPGs) for neonatal hypoxic ischemic encephalopathy (HIE), and map their recommendations.

Data Sources

CPG databases (GIN, ECRI, NICE, SIGN, DynaMed), Bibliographic databases (PubMed, Embase, CINAHL), and related specialized professional societies (e.g., AAP, CPS, BAPM, RCPCH, and SNS).

Study Selection

Original de-novo developed evidence-based CPGs for HIE, group authorship, Arabic or English languages, and international or national scope. The systematic review was drafted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement and Johnston et al methodological guide.

Data Extraction

Quality assessment of the included HIE CPGs by the Appraisal of Guidelines for REsearch & Evaluation II (AGREE II) Instrument and report their characteristics, AGREE II ratings, and recommendations.

Data Synthesis

Our search retrieved 2,489 citations, of which two recent HIE CPGs were eligible and appraised: Canadian Paediatric Society (CPS) and Queensland Maternity and Neonatal Services (QMN). The overall assessment of the QMN CPG was superior (83%). Domain 1 (Scope & Purpose) scored (47%, 63%), Domain 2 (Stakeholder Involvement) (72%, 39%), Domain 3 (Rigour of Development) (48%, 43%), Domain 4 (Clarity & Presentation) (100%, 96%), Domain 5 (Applicability) (59%, 9%), and Domain 6 (Editorial Independence) (67%, 17%) for the QMN and CPS CPGs respectively. All appraisers recommended the QMN CPG for use in practice.

Conclusion

The methodological quality of the QMN CPG was superior with the relevant recommendations for its use in neonatal practice.

Limitations

limited to Arabic and English languages.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=258291, identifier: CRD42021258291.

Availability of active therapeutic hypothermia at birth for neonatal hypoxic ischaemic encephalopathy: a UK population study from 2011 to 2018

OBJECTIVE

Therapeutic hypothermia (TH) commenced soon after birth for neonatal hypoxic ischaemic encephalopathy (HIE) improves survival and reduces neurodisability. Availability of active TH at the place of birth (Immediate-TH) in the UK is unknown.

DESIGN

Population-based observational study.

SETTING

UK maternity centres.

PATIENTS

5 975 056 births from 2011 to 2018.

INTERVENTION METHODS

For each maternity centre, the year active Immediate-TH was available and the annual birth rates were established. Admission temperatures of infants with HIE transferred from non-tertiary centres with and without Immediate-TH were compared.

MAIN OUTCOME MEASURES

Quantify the annual number of births with access to Immediate-TH. Secondary outcomes included temporal changes in Immediate-TH and admission temperatures for infants requiring transfer to tertiary centres.

RESULTS

In UK maternity centres, 75 of 194 (38.7%) provided Immediate-TH in 2011 rising to 95 of 192 (49.5%, p=0.003) in 2018 with marked regional variations. In 2011, 394 842 (51.2%) of 771 176 births had no access to Immediate-TH compared with 276 258 (39.3%) of 702 794 births in 2018 (p<0.001). More infants with HIE arrived in the therapeutic temperature range (76.5% vs 67.3%; OR 1.58, 95% CI 1.25 to 2.0, p<0.001) with less overcooling (10.6% vs 14.3%; OR 0.71, 95% CI 0.51 to 0.98, p=0.036) from centres with Immediate-TH compared with those without.

CONCLUSIONS

Availability of active Immediate-TH has slowly increased although many newborns still have no access and rely on transport team arrival to commence active TH. This is associated with delayed optimal hypothermic management. Provision of Immediate-TH across all units, with appropriate training and support, could improve care of infants with HIE.

Review of a frugal cooling mattress to induce therapeutic hypothermia for treatment of hypoxic-ischaemic encephalopathy in the UK NHS

Hypoxic ischaemic encephalopathy (HIE) is a major cause of neonatal mortality and disability in the United Kingdom (UK) and has significant human and financial costs. Therapeutic hypothermia (TH), which consists of cooling down the newborn’s body temperature, is the current standard of treatment for moderate or severe cases of HIE. Timely initiation of treatment is critical to reduce risk of mortality and disability associated with HIE. Very expensive servo-controlled devices are currently used in high-income settings to induce TH, whereas low-income settings rely on the use of low-tech devices such as water bottles, ice packs or fans. Cooling mattresses made with phase change materials (PCMs) were recently developed as a safe, efficient, and affordable alternative to induce TH in low-income settings. This frugal innovation has the potential to become a reverse innovation for the National Health Service (NHS) by providing a simple, efficient, and cost-saving solution to initiate TH in geographically remote areas of the UK where cooling equipment might not be readily available, ensuring timely initiation of treatment while waiting for neonatal transport to the nearest cooling centre. The adoption of PCM cooling mattresses by the NHS may reduce geographical disparity in the availability of treatment for HIE in the UK, and it could benefit from improvements in coordination across all levels of neonatal care given challenges currently experienced by the NHS in terms of constraints on funding and shortage of staff. Trials evaluating the effectiveness and safety of PCM cooling mattresses in the NHS context are needed in support of the adoption of this frugal innovation. These findings may be relevant to other high-income settings that experience challenges with the provision of TH in geographically remote areas. The use of promising frugal innovations such as PCM cooling mattresses in high-income settings may also contribute to challenge the dominant narrative that often favours innovation from North America and Western Europe, and consequently fight bias against research and development from low-income settings, promoting a more equitable global innovation landscape.

Treating Seizures after Hypoxic-Ischemic Encephalopathy-Current Controversies and Future Directions

Seizures are common in newborn infants with hypoxic-ischemic encephalopathy and are highly associated with adverse neurodevelopmental outcomes. The impact of seizure activity on the developing brain and the most effective way to manage these seizures remain surprisingly poorly understood, particularly in the era of therapeutic hypothermia. Critically, the extent to which seizures exacerbate brain injury or merely reflect the underlying evolution of injury is unclear. Current anticonvulsants, such as phenobarbital and phenytoin have poor efficacy and preclinical studies suggest that most anticonvulsants are associated with adverse effects on the developing brain. Levetiracetam seems to have less potential neurotoxic effects than other anticonvulsants but may not be more effective. Given that therapeutic hypothermia itself has significant anticonvulsant effects, randomized controlled trials of anticonvulsants combined with therapeutic hypothermia, are required to properly determine the safety and efficacy of these drugs. Small clinical studies suggest that prophylactic phenobarbital administration may improve neurodevelopmental outcomes compared to delayed administration; however, larger high-quality studies are required to confirm this. In conclusion, there is a distinct lack of high-quality evidence for whether and to what extent neonatal seizures exacerbate brain damage after hypoxia-ischemia and how best to manage them in the era of therapeutic hypothermia.