The TOBY Study. Whole body hypothermia for the treatment of perinatal asphyxial encephalopathy: a randomised controlled trial

Perinatal asphyxia with no or mild hypoxic-ischaemic encephalopathy: Two-year neurodevelopmental outcome

OBJECTIVE

To characterize 2-year neurodevelopment of infants with perinatal asphyxia without hypoxic-ischemic encephalopathy (HIE) or with mild HIE (HIE1) and analyse possible correlations with sex, brain MRI findings or early neurological examination.

METHODS

Term infants with perinatal asphyxia and a control group were prospectively recruited from the neonatal units of Helsinki University Hospital in 2016-2020. The study cohort included infants with no or minor neurological symptoms during first 6 h after birth. Neurodevelopment was assessed using Hammersmith Infant Neurological Examination (HINE) at three months and at two years, Griffiths Scales of Child Development, 3rd edition (GMDS-III) and Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID-III) at two years.

RESULTS

Study included 89 infants: 32 study cohort infants and 57 healthy controls. In the study cohort 1/32 and in the control group 0/57 of the infants showed significantly below normative mean cognitive score in BSID-III. Respective frequency of significantly below normative mean receptive language score were 2/32 and 0/57 and expressive language score 4/32 and 8/57. Females with perinatal asphyxia performed better in the language scores of GMDS-III and BSID-III. Children with asphyxia-related findings in brain MRI had statistically significantly lower total score, language and communication and foundations of learning subscore of GMDS-III.

CONCLUSIONS

Most infants with perinatal asphyxia without HIE or with HIE1 performed typically at two years. However, infants with asphyxia-related MRI findings showed lower cognitive and language scores. Our results suggest that female sex may be associated with a lower risk of any subtle effects.

Intraventricular hemorrhage among very low birth weight infants in a South African cohort: a retrospective study of trends & short-term outcomes

BACKGROUND

Intraventricular hemorrhage (IVH) is one of the critical complications of prematurity with severe forms, associated with irreversible brain damage. We hypothesized that infants born in South Africa may have different modifiable risk factors and outcomes for severe IVH compared to that reported in studies in neonatal populations in higher resource settings. Our study aimed to define the prevalence of IVH with further characterization of risk factors based on IVH severity, with the goal of providing guidance on modification of protocols for the management and prevention of severe IVH.

METHODS

This was a retrospective cohort study of very low birth weight infants admitted to the NICU of Charlotte Maxeke Academic Hospital in Johannesburg (CMJAH) from January 1, 2016, to December 31, 2020. Our study included all infants, weighing less than 1500 g, admitted to the hospital regardless of place of birth who had had at least one cranial ultrasound in the first week of life. Infants with other intracranial malformations than IVH, birth weights greater than 1500 g, and significant amount of missing data were excluded from the study. Maternal and neonatal information were extracted from an existing neonatal database and analyzed using R statistical software. Multivariable logistic regressions were used to investigate risk factors associated with increased odds of having IVH and its impact on mortality.

RESULTS

A total of 2,217 very low birthweight (VLBW) infants admitted to the NICU at CMJAH during the study period met eligibility criteria. Median gestational age (GA) and birth weight (BW) were 28 weeks and 900 g, respectively. IVH prevalence was 22.6% with high grade IVH (grade 3 or 4) accounting for 6.8% of the cases. Infants with high grade IVH had 4-fold increase odds of dying (OR = 4.843, 95% CI = 2.984; 7.86, p < 0.001). Acidosis was associated with increased odds of high grade IVH (OR = 2.27; 95%CI: 1.42; 3.64). Similarly, infants with early onset sepsis had higher odds of high grade IVH (OR = 2.22; 95%CI: 1.04; 4.75).

CONCLUSIONS

Acidosis and sepsis had a significant association with the occurrence of severe IVH. Antenatal steroids showed an association with occurrence and severity suggesting it may play an important role, but did not reach significance so must be further evaluated. Having severe IVH substantially increased the odds of death. Based on these findings, future directions could include collaborative QI projects with obstetricians to improve uptake of antenatal steroids and promotion of neonatology led QI projects to reduce risk factors associated with severe IVH.

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.

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.

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.

The predictive value of MRI scores for neurodevelopmental outcome in infants with neonatal encephalopathy

BACKGROUND

MRI scoring systems are utilized to quantify brain injury and predict outcome in infants with neonatal encephalopathy (NE). Our aim was to evaluate the predictive accuracy of total scores, white matter (WM) and grey matter (GM) subscores of Barkovich and Weeke scoring systems for neurodevelopmental outcome at 2 years of age in infants receiving therapeutic hypothermia for NE.

METHODS

Data of 162 infants were analyzed in this retrospective cohort study. DeLong tests were used to compare areas under the curve of corresponding items of the two scoring systems. LASSO logistic regression was carried out to evaluate the association between MRI scores and adverse composite (death or severe disabilities), motor and cognitive outcomes (Bayley developmental index <70).

RESULTS

Weeke scores predicted each outcome measure with greater accuracy than the corresponding items of Barkovich system (DeLong tests p < 0.03). Total scores, GM and cerebellum involvement were associated with increased odds for adverse outcomes, in contrast to WM injury, after adjustment to 5' Apgar score, first postnatal lactate and aEEG normalization within 48 h.

CONCLUSION

A more detailed scoring system had better predictive value for adverse outcome. GM injury graded on both scoring systems was an independent predictor of each outcome measure.

IMPACT STATEMENTS

A more detailed MRI scoring system had a better predictive value for motor, cognitive and composite outcomes. While hypoxic-ischemic brain injuries in the deep grey matter and cerebellum were predictive of adverse outcome, white matter injury including cortical involvement was not associated with any of the outcome measures at 2 years of age. Structured MRI evaluation based on validated scores may aid future clinical research, as well as inform parents and caregivers to optimize care beyond the neonatal period.

Early hypoglycemia is not an independent risk factor for 2-year cognitive impairment in small for gestational age preterm infants of less than 32 weeks

The objective of this study is to evaluate whether early hypoglycemia is an independent risk factor for 2-year cognitive (COG) impairment in small for gestational age (SGA) preterm infants with gestational age (GA) < 32 weeks. We retrospectively reviewed data of 1364 preterm infants with a GA 24+0/7-31+6/7 weeks. Infants were classified based on blood glucose concentrations within the first 6 h of life (HOL) as < or ≥ 40 mg/dL (Glyc < 40[Birth-6HOL] and Glyc ≥ 40[Birth-6HOL], respectively) and subsequently by birth weight z-score as SGA or appropriate for gestational age (AGA). Propensity score matching analyses were conducted for each comparison. Multiple logistic regression was used to evaluate the association of Glyc < 40[Birth-6HOL] with 2-year COG impairment, defined as a Bayley-III score < 85, in SGA infants. Out of the 747 preterm infants who met the inclusion criteria, 173 (23.2%) were classified as Glyc < 40[Birth-6HOL], and 574 (76.8%) as Glyc ≥ 40[Birth-6HOL]. The proportion of SGA infants was significantly higher in Glyc < 40[Birth-6HOL] than in Glyc ≥ 40[Birth-6HOL] (25.4 vs 18.3%, p = 0.039). The incidence of 2-year COG impairment was significantly higher in SGA infants compared to matched AGA counterparts both in Glyc < 40[Birth-6HOL] (+ 20%, p = 0.040) and Glyc ≥ 40[Birth-6HOL] (+ 17%, p = 0.029). Neither in the entire cohort nor in the SGA infants, Glyc < 40[Birth-6HOL] was significantly associated with 2-year COG impairment (aOR: 1.077, p = 0.768; 0.993, p = 0.935; respectively) after the adjustment for GA, sex, Apgar score at 5 min < 7, SGA status, complications of prematurity, duration of mechanical ventilator support > 7 days, cumulative energy intakes from birth to 36 weeks, and maternal university level.

CONCLUSION

 Among SGA preterm infants with GA between 24+0/7 and 31+6/7 weeks/days, hypoglycemia within the first 6 HOL was not an independent risk factor for 2-year COG impairment.

WHAT IS KNOWN

• Hypoglycemia is associated with poor neurodevelopmental outcomes in preterm infants. • Small for gestational age (SGA) preterm infants are more prone to cognitive (COG) impairment compared to AGA counterparts.

WHAT IS NEW

• In a large cohort of preterm infants < 32 weeks, the incidence of hypoglycemia within the first 6 hours of life (HOL) was higher in SGA compared to AGA. • Hypoglycemia within the first 6 HOL was not an independent risk factor for 2-year COG impairment in SGA preterm infants.

Uneven Distribution of Purkinje Cell Injury in the Cerebellar Vermis of Term Neonates with Hypoxic-Ischemic Encephalopathy

In term neonates with hypoxic-ischemic encephalopathy (HIE), cerebellar injury is becoming more and more acknowledged. Animal studies demonstrated that Purkinje cells (PCs) are especially vulnerable for hypoxic-ischemic injury. In neonates, however, the extent and pattern of PC injury has not been investigated. The aim of this study was to characterize the morphology and distribution of PCs in the cerebellar vermis of term born neonates with HIE. Twenty-two term born neonates with severe HIE, several of which received therapeutic hypothermia, who underwent post-mortem autopsy of the brain including cerebellar vermis within three to five days after birth were included. Haematoxylin & Eosin (H&E) stained sections of the vermis were used to determine total PC count and morphology (normal, abnormal or non-classified) at the bases and crowns of the folia and of the lobules in both the anterior and posterior lobes. Differences in PC count and PC morphology between the anterior and posterior lobe and between the bases and crowns were compared. The total number of PCs was significantly higher at the crowns compared to the bases (p < 0.001) irrespective of the precise location. Besides, PCs at the bases more often had an abnormal morphology. Also, a significant difference between the injury in the anterior and posterior lobe was observed, notably at specific microscopic locations with more abnormal PCs in the posterior lobe. The number of PCs scored as abnormal was increased in the bases compared to the crowns, which might resemble supratentorial ulegyria.

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.

Hearing loss in newborn infants with hypoxic ischaemic encephalopathy: protocol for a case-control study

INTRODUCTION

Hypoxic ischaemic encephalopathy (HIE), a condition where the brain does not receive enough oxygen and/or blood flow around the time of birth, is associated with significant morbidity and mortality. Systemic circulation may be affected due to poor myocardial function. The cochlear hair cells are vulnerable to changes in microcirculation, which may occur in HIE predisposing to hearing loss. Therefore, all infants with HIE undergo neurodevelopmental surveillance after discharge to monitor for adverse neurodevelopment including speech and hearing problems. This study will examine the incidence of confirmed hearing loss in newborn infants with any stage of HIE (cases) and compare them with controls.

METHODS AND ANALYSIS

All infants diagnosed with any stage of HIE (cases) over a 12-year period (January 2010 to December 2021) will be examined. Controls were newborn infants without HIE who were admitted to the neonatal unit and received intensive care including antibiotics (control group 1) and stable infants in the postnatal ward who received antibiotics (eg, gentamicin) (control group 2). Controls matched for gestation, gender and birth weight will be selected from a similar time period. Infant details and hearing screening data will be gathered from prospectively entered BadgerNet and S4H system databases, respectively. Categorical data will be analysed using the χ2 test. Predictors for hearing loss will be performed using binary logistic regression analysis.

ETHICS AND DISSEMINATION

The study is approved by the Health and Care Research Wales (HCRW) Research Ethics Committee and the Health Research Authority (HRA) (reference 21/HRA/4506). The study findings will be presented at national/international conferences and published in peer-reviewed scientific journals.

Practice Variations for Therapeutic Hypothermia in Neonates with Hypoxic-ischemic Encephalopathy: An International Survey

OBJECTIVE

To evaluate variations in management of therapeutic hypothermia (TH) for neonatal hypoxic-ischemic encephalopathy (HIE) among international clinical sites and to identify areas for harmonization.

STUDY DESIGN

An electronic survey was sent to Children's Hospitals Neonatal Consortium site sponsors, Canadian Neonatal Network site investigators, members of the Newborn Brain Society, and American Academy of Pediatrics Neonatology chiefs.

RESULTS

One hundred five sites responded, with most from high-income regions (n = 95). Groupings were adapted from the United Nations regional groups: US (n = 52 sites); Canada (n = 20); Western Europe and other states excluding Canada and US Group (WEOG, n = 18); and non-WEOG (central and eastern Europe, Asia, Africa, Latin America, and Caribbean, n = 15). Regional variations were seen in the eligibility criteria for TH, such as the minimum gestational age, grading of HIE severity, use of electroencephalography, and the frequency of providing TH for mild HIE. Active TH during transport varied among regions and was less likely in smaller volume sites. Amplitude-integrated electroencephalogram and/or continuous electroencephalogram to determine eligibility for TH was used by most sites in WEOG and non-WEOG but infrequently by the US and Canada Groups. For sedation during TH, morphine was most frequently used as first choice but there was relatively high (33%) use of dexmedetomidine in the US Group. Timing of brain magnetic resonance imaging and neurodevelopmental follow-up were variable. Neurodevelopmental follow occurred earlier and more frequently, although for a shorter duration, in the non-WEOG.

CONCLUSIONS

We found significant variations in practices for TH for HIE across regions internationally. Future guidelines should incorporate resource availability in a global perspective.

Neonatal encephalopathy due to suspected hypoxic ischemic encephalopathy: pathophysiology, current, and emerging treatments

BACKGROUND

Neonatal encephalopathy (NE) due to suspected hypoxic-ischemic encephalopathy (HIE), referred to as NESHIE, is a clinical diagnosis in late preterm and term newborns. It occurs as a result of impaired cerebral blood flow and oxygen delivery during the peripartum period and is used until other causes of NE have been discounted and HIE is confirmed. Therapeutic hypothermia (TH) is the only evidence-based and clinically approved treatment modality for HIE. However, the limited efficacy and uncertain benefits of TH in some low- to middle-income countries (LMICs) and the associated need for intensive monitoring have prompted investigations into more accessible and effective stand-alone or additive treatment options.

DATA SOURCES

This review describes the rationale and current evidence for alternative treatments in the context of the pathophysiology of HIE based on literatures from Pubmed and other online sources of published data.

RESULTS

The underlining mechanisms of neurotoxic effect, current clinically approved treatment, various categories of emerging treatments and clinical trials for NE are summarized in this review. Melatonin, caffeine citrate, autologous cord blood stem cells, Epoetin alfa and Allopurinal are being tested as potential neuroprotective agents currently.

CONCLUSION

This review describes the rationale and current evidence for alternative treatments in the context of the pathophysiology of HIE. Neuroprotective agents are currently only being investigated in high- and middle-income settings. Results from these trials will need to be interpreted and validated in LMIC settings. The focus of future research should therefore be on the development of inexpensive, accessible monotherapies and should include LMICs, where the highest burden of NESHIE exists.

Cardiac function at follow-up in infants treated with therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy

BACKGROUND

Compromised myocardial function and persistent elevated pulmonary vascular resistance are common among neonates treated with therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE). There is a lack of data regarding persistence of cardiac alterations after discharge from the neonatal intensive care unit (NICU).

METHODS

We assessed cardiovascular profiles after NICU discharge. Echocardiogram data, including speckle-tracking echocardiography (STE), were extracted from the latest outpatient scan. Data were compared by initial amplitude-integrated encephalography (aEEG) profiles on admission [normal vs. abnormal].

RESULTS

In total, 70 (19%) neonates had a follow-up echocardiogram (22 with initial normal aEEG, 48 with abnormal aEEG). Age at follow-up was similar between the two groups (6.2 vs. 7.7 months, [p = 0.08]). Neonates with an initially abnormal aEEG showed more negative Right Ventricle (RV)-peak global longitudinal strain (-28.2 vs. -26.0%, [p = 0.02]), RV-peak free wall longitudinal strain rate (-1.24 vs. -1.10 [1/second], [p = 0.01]), and RV-peak free wall longitudinal strain rate (-1.50 vs. -1.27 [1/second], [p = 0.001]). These associations remained after multilinear regression analysis, indicating persistent enhanced RV contraction in the abnormal aEEG group.

CONCLUSION

Neonates with initial abnormal aEEG profiles exhibited increased RV contraction after NICU discharge. Future studies should explore long-term cardiovascular follow-up of neonates with HIE, beyond the perinatal period.

IMPACT

What is the key message of your article? Cardiac performance in hypoxic ischemic encephalopathy is linked to adverse outcomes. Survivors with an abnormal aEEG at admission showed increased right ventricular contractility at follow-up, possibly related to an adverse adaptation to the initial insult. What does it add to the existing literature? This study offers insights into long-term cardiovascular outcomes in neonates with HIE, focusing on the link between initial aEEG abnormalities and later RV function. What is the impact? The findings underscore the importance of early cardiovascular assessments and monitoring in neonates undergoing TH for HIE, potentially guiding future follow-up protocols.

Fifteen Years of Neonatal Therapeutic Hypothermia: Clinical Trends Show Unchanged Post-Rewarming Outcomes despite Reduction in Hypoxic-Ischemic Encephalopathy Severity

INTRODUCTION

Hypoxic-ischemic encephalopathy (HIE) affects 1-2 per 1,000 births and is associated with mortality and long-term neurodevelopmental challenges. At present, therapeutic hypothermia (TH) is the only neuroprotective intervention for these infants. This study examines whether HIE severity, clinical management during TH, and post-rewarming outcomes have changed since its introduction 15 years ago.

METHODS

Neonatal characteristics, HIE severity, management during TH, and post-rewarming MRI of all infants with HIE undergoing TH between 2008 and 2023 were compared across three five-year epochs. Linear regression was used to estimate annual changes over time.

RESULTS

In total, 252 infants underwent TH. Median gestational age (39.5 weeks), birth weight (3,376 g), and time to start TH (4.25 h) remained stable over time. Apgar score at 5 min (p = 0.031) and lowest pH <1 h postpartum (p = 0.020) increased over time. Thompson score at 1-3 h decreased across epochs (p = 0.046). There was an increase in percentage with normal-mild aEEG background patterns on admission (p = 0.041) and a decrease in aEEG-confirmed seizures (p < 0.001) and antiseizure medication (p < 0.001). Inotropic support decreased (p = 0.007), and use of invasive mechanical ventilation decreased over the last 5 years. Mortality (28.6%) and post-rewarming composite adverse outcome (i.e., neonatal mortality and/or adverse MRI score) (37.9%) remained unchanged. Number of infants seen at 2-year follow-up increased (p < 0.001).

CONCLUSION

Over the last 15 years, we treated more infants with milder HIE, as indicated by lower Thompson and milder aEEG scores, and the need for invasive cardiorespiratory support declined. However, there were no improvements in composite adverse outcome (mortality and/or adverse MRI score).

Exploring the potential cost-effectiveness of a new computerised decision support tool for identifying fetal compromise during monitored term labours: an early health economic model

BACKGROUND

Around 60% of term labours in the UK are continuously monitored using cardiotocography (CTG) to guide clinical labour management. Interpreting the CTG trace is challenging, leading to some babies suffering adverse outcomes and others unnecessary expedited deliveries. A new data driven computerised tool combining multiple clinical risk factors with CTG data (attentive CTG) was developed to help identify term babies at risk of severe compromise during labour. This paper presents an early health economic model exploring its potential cost-effectiveness.

METHODS

The model compared attentive CTG and usual care with usual care alone and simulated clinical events, healthcare costs, and infant quality-adjusted life years over 18 years. It was populated using data from a cohort of term pregnancies, the literature, and administrative datasets. Attentive CTG effectiveness was projected through improved monitoring sensitivity/specificity and potential reductions in numbers of severely compromised infants. Scenario analyses explored the impact of including litigation costs.

RESULTS

Nationally, attentive CTG could potentially avoid 10,000 unnecessary alerts in labour and 2400 emergency C-section deliveries through improved specificity. A reduction of 21 intrapartum stillbirths amongst severely compromised infants was also predicted with improved sensitivity. Attentive CTG could potentially lead to cost savings and health gains with a probability of being cost-effective at £25,000 per QALY ranging from 70 to 95%. Potential exists for further cost savings if litigation costs are included.

CONCLUSIONS

Attentive CTG could offer a cost-effective use of healthcare resources. Prospective patient-level studies are needed to formally evaluate its effectiveness and economic impact in routine clinical practice.

Servo-controlled therapeutic hypothermia during neonatal transport: a before-and-after quality improvement project

The purpose of this paper is to compare the achievement of target temperature and the short-term neurological outcome according to the use of servo-controlled hypothermia in transport. This is a monocentric retrospective observational before-and-after uncontrolled study of newborns transported for neonatal encephalopathy. The first group was transported from 01/01/2019 to 12/31/2019 in passive hypothermia and the second group from 01/01/2021 to 12/31/2021 in controlled hypothermia. We included patients who had a total of 72 h of servo-controlled therapeutic hypothermia (CTH). We excluded those who had no or less than 72 h of CTH. There were 33 children transported in passive hypothermia in 2019 and 23 children transported in CTH in 2021. There were 9/28 (32%) patients in 2019 who reached the target temperature on arrival at the NICU compared with 20/20 (100%) in 2021 (p value < 0.01). There was a trend towards earlier age of therapeutic hypothermia if started in transport: 3.1 h ± 1.0 vs 4.0 h ± 2.4 for passive hypothermia (p value 0.07). There was no difference in age of arrival in NICU (4.0 h ± 1.2 with CTH vs 3.8 h ± 2.2 without CTH). We found no difference in short-term outcome (survival, abnormal MRI, seizures on EEG) between the two groups.

CONCLUSION

The use of servo-controlled therapeutic hypothermia makes it possible to reach the temperature target, without increasing the age of arrival in the NICU.

WHAT IS KNOWN

• CTH is rarely used during transport in France even if passive hypothermia rarely reaches temperature target, inducing overcooling and hyperthermia.

WHAT IS NEW

• This study shows better temperature control on arrival in the NICU with CTH compared to passive hypothermia, with no increase in arrival time.

Early automated classification of neonatal hypoxic-ischemic encephalopathy - An aid to the decision to use therapeutic hypothermia

OBJECTIVE

The study aimed to address the challenge of early assessment of neonatal hypoxic-ischemic encephalopathy (HIE) severity to identify candidates for therapeutic hypothermia (TH). The objective was to develop an automated classification model for neonatal EEGs, enabling accurate HIE severity assessment 24/7.

METHODS

EEGs recorded within 6 h of life after perinatal anoxia were visually graded into 3 severity groups (HIE French Classification) and quantified using 6 qEEG markers measuring amplitude, continuity and frequency content. Machine learning models were developed on a dataset of 90 EEGs and validated on an independent dataset of 60 EEGs.

RESULTS

The selected model achieved an overall accuracy of 80.6% in the development phase and 80% in the validation phase. Notably, the model accurately identified 28 out of 30 children for whom TH was indicated after visual EEG analysis, with only 2 cases (moderate EEG abnormalities) not recommended for cooling.

CONCLUSIONS

The combination of clinically relevant qEEG markers led to the development of an effective automated EEG classification model, particularly suited for the post-anoxic latency phase. This model successfully discriminated neonates requiring TH.

SIGNIFICANCE

The proposed model has potential as a bedside clinical decision support tool for TH.

Blood product transfusion practices in neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

Blood product transfusion is a common practice in infants with hypoxic-ischemic encephalopathy (HIE) undoing therapeutic hypothermia (TH). The advantages and disadvantages of conservative or liberal transfusion practices in this fragile population are unknown. Study aims to characterize the transfusion practices in infants with HIE and investigate the association with outcome.

STUDY DESIGN

We conducted a retrospective cohort study at a single level IV NICU, evaluating transfusion thresholds, as well as the association between hematological abnormalities or blood product transfusions and outcomes in infants admitted with HIE.

RESULT

By univariate analysis, FFP transfusion was associated with increased in-hospital death. However, multivariate analysis adjusting for HIE severity demonstrated no association between hematological abnormality or blood product transfusion and death, nor with neurodevelopmental impairment.

CONCLUSION

No association was found between hematological blood product transfusion and death or neurodevelopmental impairment in a retrospective single NICU study of infants with HIE.

Pipeline to Neonatal Clinical Transformation: The Importance of Preclinical Data

Historically, neonatal neuroscience boasted a robust and successful preclinical pipeline for therapeutic interventions, in particular for the treatment of hypoxic-ischemic encephalopathy (HIE). However, since the successful translation of therapeutic hypothermia (TH), several high-profile failures of promising adjunctive therapies, in addition to the lack of benefit of TH in lower resource settings, have brought to light critical issues in that same pipeline. Using recent data from clinical trials of erythropoietin as an example, the authors highlight several key challenges facing preclinical neonatal neuroscience for HIE therapeutic development and propose key areas where model development and collaboration across the field in general can ensure ongoing success in treatment development for HIE worldwide.

Short-term outcomes of asphyxiated neonates depending on requirement for transfer in the first 24 h of life

IMPORTANCE

In neonates with birth asphyxia (BA) and hypoxic-ischemic encephalopathy, therapeutic hypothermia (TH), initiated within six hours, is the only safe and established neuroprotective measure to prevent secondary brain injury. Infants born outside of TH centers have delayed access to cooling.

OBJECTIVE

To compare in-hospital mortality, occurrence of seizures, and functional status at discharge in newborns with BA depending on postnatal transfer for treatment to another hospital within 24 h of admission (transferred (TN) versus non-transferred neonates (NTN)).

DESIGN

Nationwide retrospective cohort study from a comprehensive hospital dataset using codes of the International Classification of Diseases, 10th modification (ICD-10). Clinical and outcome information was retrieved from diagnostic and procedural codes. Hierarchical multilevel logistic regression modeling was performed to quantify the effect of being postnatally transferred on target outcomes.

SETTING

All discharges from German hospitals from 2016 to 2021.

PARTICIPANTS

Full term neonates with birth asphyxia (ICD-10 code: P21) admitted to a pediatric department on their first day of life.

EXPOSURES

Postnatal transfer to a pediatric department within 24 h of admission to an external hospital.

MAIN OUTCOMES

In-hospital death; secondary outcomes: seizures and pediatric complex chronic conditions category (PCCC) ≥ 2.

RESULTS

Of 11,703,800 pediatric cases, 25,914 fulfilled the inclusion criteria. TNs had higher proportions of organ dysfunction, TH, organ replacement therapies, and neurological sequelae in spite of slightly lower proportions of maternal risk factors. In TNs, the adjusted odds ratios (OR) for death, seizures, and PCCC ≥ 2 were 4.08 ((95% confidence interval 3.41-4.89), 2.99 (2.65-3.38), and 1.76 (1.52-2.05), respectively. A subgroup analysis among infants receiving TH (n = 3,283) found less pronounced adjusted ORs for death (1.67 (1.29-2.17)) and seizures (1.26 (1.07-1.48)) and inverse effects for PCCC ≥ 2 (0.81 (0.64-1.02)) in TNs.

CONCLUSION AND RELEVANCE

This comprehensive nationwide study found increased odds for adverse outcomes in neonates with BA who were transferred to another facility within 24 h of hospital admission. Closely linking obstetrical units to a pediatric department and balancing geographical coverage of different levels of care facilities might help to minimize risks for postnatal emergency transfer and optimize perinatal care.

Reverse Therapy: Impact of Hyperthermia and Rewarming on Newborn Outcomes

Therapeutic hypothermia is now well established to improve neurodevelopmental outcomes after hypoxic-ischemic encephalopathy (HIE). Although the overall principles of treatment are now well established, many smaller questions are unclear. The potential impact of reversal of hypothermia therapy and the effect of high temperatures on recovery of the neurovascular unit after therapeutic hypothermia for HIE has received relatively little attention. This article will address the effects of hypoxia-ischemia and rewarming and increased temperatures on the neurovascular unit in preclinical and clinical models.

SMYD5 is a regulator of the mild hypothermia response

The mild hypothermia response (MHR) maintains organismal homeostasis during cold exposure and is thought to be critical for the neuroprotection documented with therapeutic hypothermia. To date, little is known about the transcriptional regulation of the MHR. We utilize a forward CRISPR-Cas9 mutagenesis screen to identify the histone lysine methyltransferase SMYD5 as a regulator of the MHR. SMYD5 represses the key MHR gene SP1 at euthermia. This repression correlates with temperature-dependent levels of histone H3 lysine 26 trimethylation (H3K36me3) at the SP1 locus and globally, indicating that the mammalian MHR is regulated at the level of histone modifications. We have identified 37 additional SMYD5-regulated temperature-dependent genes, suggesting a broader MHR-related role for SMYD5. Our study provides an example of how histone modifications integrate environmental cues into the genetic circuitry of mammalian cells and provides insights that may yield therapeutic avenues for neuroprotection after catastrophic events.

Cooling during transportation of newborns with hypoxic ischemic encephalopathy using phase change material mattresses in low-resource settings: a randomized controlled trial in Hanoi, Vietnam

OBJECTIVE

To determine the effectiveness of phase-change-material mattress (PCM) during transportation of newborns with hypoxic ischemic encephalopathy (HIE).

STUDY DESIGN

Randomized controlled trial of newborns with HIE from June 2016 to December 2019. Patients were randomized to transport with PCM or without PCM (control) when transferred to a cooling center in northern Vietnam. Primary outcome measure was mortality rate, secondary outcomes including temperature control and adverse effects.

RESULT

Fifty-Two patients in PCM-group and 61 in control group. Median rectal temperature upon arrival was 34.5 °C (IQR 33.5-34.8) in PCM-group and 35.1 °C (IQR 34.5-35.9) in control group (p = 0.023). Median time from birth to reach target temperature was 5.0 ± 1.4 h and 5.5 ± 1.2 h in the respective groups (p = 0.065). 81% of those transported with PCM versus 62% of infants transported without (p = 0.049) had reached target temperature within the 6-h timeframe. There was no record of overcooling (< 32 °C) in any of the groups. The was no difference in mortality rate between the two groups (33% and 34% respectively (p > 0.05)).

CONCLUSION

Phase-change-material can be used as a safe and effective cooling method during transportation of newborns with HIE in low-resource settings.

TRIAL REGISTRATION

The study was retro-prospectively registered in Clinical Trials (04/05/2022, NCT05361473).

Drug Disposition in Neonatal Göttingen Minipigs: Exploring Effects of Perinatal Asphyxia and Therapeutic Hypothermia

Asphyxiated neonates often undergo therapeutic hypothermia (TH) to reduce morbidity and mortality. Since both perinatal asphyxia (PA) and TH influence physiology, altered pharmacokinetics (PK) and pharmacodynamics (PD) are expected. Given that TH is the standard of care for PA with moderate to severe hypoxic-ischemic encephalopathy, disentangling the effect of PA versus TH on PK/PD is not possible in clinical settings. However, animal models can provide insights into this matter. The (neonatal) Göttingen Minipig, the recommended strain for nonclinical drug development, was selected as translational model. Four drugs-midazolam (MDZ), fentanyl (FNT), phenobarbital (PHB), and topiramate (TPM)-were intravenously administered under four conditions: control (C), therapeutic hypothermia (TH), hypoxia (H), and hypoxia plus TH (H+TH). Each group included six healthy male neonatal Göttingen Minipigs anesthetized for 24 hours. Blood samples were drawn at 0 (predose) and 0.5, 2, 2.5, 3, 4, 4.5, 6, 8, 12, and 24 hours post drug administration. Drug plasma concentrations were determined using validated bioanalytical assays. The PK parameters were estimated through compartmental and noncompartmental PK analysis. The study showed a statistically significant decrease in FNT clearance (CL; 66% decrease), with an approximately threefold longer half-life (t1/2) in the TH group. The H+TH group showed a 17% reduction in FNT CL, with a 62% longer t1/2 compared with the C group; however, it was not statistically significant. Although not statistically significant, trends toward lower CL and longer t1/2 were observed in the TH and H+TH groups for MDZ and PHB. Additionally, TPM demonstrated a 28% decrease in CL in the H group compared with controls. SIGNIFICANCE STATEMENT: The overarching goal of this study using the neonatal Göttingen Minipig model was to disentangle the effects of systemic hypoxia and TH on PK using four model drugs. Such insights can subsequently be used to inform and develop a physiologically based pharmacokinetic model, which is useful for drug exposure prediction in human neonates.

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 therapeutic hypothermia (TH) 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 0.5/1,000 California births to a peak of 1.5/1,000 births in 2018. The use of TH 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 TH.

Conclusion

Significantly more infants with mild HIE received TH since 2015 in California, but no difference in outcomes was found for these patients.

Clinical outcome prediction with an automated EEG trend, Brain State of the Newborn, after perinatal asphyxia

OBJECTIVE

To evaluate the utility of a fully automated deep learning -based quantitative measure of EEG background, Brain State of the Newborn (BSN), for early prediction of clinical outcome at four years of age.

METHODS

The EEG monitoring data from eighty consecutive newborns was analyzed using the automatically computed BSN trend. BSN levels during the first days of life (a of total 5427 hours) were compared to four clinical outcome categories: favorable, cerebral palsy (CP), CP with epilepsy, and death. The time dependent changes in BSN-based prediction for different outcomes were assessed by positive/negative predictive value (PPV/NPV) and by estimating the area under the receiver operating characteristic curve (AUC).

RESULTS

The BSN values were closely aligned with four visually determined EEG categories (p < 0·001), as well as with respect to clinical milestones of EEG recovery in perinatal Hypoxic Ischemic Encephalopathy (HIE; p < 0·003). Favorable outcome was related to a rapid recovery of the BSN trend, while worse outcomes related to a slow BSN recovery. Outcome predictions with BSN were accurate from 6 to 48 hours of age: For the favorable outcome, the AUC ranged from 95 to 99% (peak at 12 hours), and for the poor outcome the AUC ranged from 96 to 99% (peak at 12 hours). The optimal BSN levels for each PPV/NPV estimate changed substantially during the first 48 hours, ranging from 20 to 80.

CONCLUSIONS

We show that the BSN provides an automated, objective, and continuous measure of brain activity in newborns.

SIGNIFICANCE

The BSN trend discloses the dynamic nature that exists in both cerebral recovery and outcome prediction, supports individualized patient care, rapid stratification and early prognosis.

The effects of CO2 levels and body temperature on brain interstitial pH alterations during the induction of hypoxic-ischemic encephalopathy in newborn pigs

Brain interstitial pH (pHbrain) alterations play a crucial role in the development of hypoxic-ischemic (HI) encephalopathy (HIE) caused by asphyxia in neonates. The newborn pig is one of the most suitable large animal models for studying HIE, however, compared to rats, experimental data on pHbrain alterations during HIE induction are limited. The major objective of the present study was thus to compare pHbrain changes during HIE development induced by experimental normocapnic hypoxia (H) or asphyxia (A), elicited with ventilation of a gas mixture containing 6%O2 or 6%O2/20%CO2, respectively for 20 min, under either normothermia (NT) or hypothermia (HT) (38.5 ± 0.5 °C or 33.5 ± 0.5 °C core temperature, respectively) in anesthetized piglets yielding four groups: H-NT, A-NT, H-HT, and A-HT. pHbrain changes during HI stress and the 60 min reoxygenation period were measured using a pH-selective microelectrode inserted into the parietal cortex through an open cranial window. In all groups, the pHbrain response to HI stress was acidosis, at the nadir pHbrain values dropped from the baseline of 7.27 ± 0.02 to H-NT:5.93 ± 0.30, A-NT:5.90 ± 0.52, H-HT:6.81 ± 0.27, and A-HT:6.27 ± 0.24 indicating that (1) H and A elicited similar, severe brain acidosis under NT greatly exceeding pH changes in arterial blood (pHa dropped to 7.24 ± 0.07 and 6.78 ± 0.03 from 7.52 ± 0.06 and 7.50 ± 0.05, respectively), and (2) HT ameliorated more the brain acidosis induced by H than by A. In all four groups, pHbrain was restored to baseline values without an alkalotic overshoot during the observed reoxygenation, Our findings suggest that under NT either H or A - both commonly employed HI stresses to elicit HIE in piglet models - would result in a similar acidotic pHbrain response without an alkalotic component either during the HI stress or the early reoxygenation period.

Socioemotional and Psychological Outcomes of Hypoxic-Ischemic Encephalopathy: A Systematic Review

BACKGROUND AND OBJECTIVES

Therapeutic hypothermia has reduced the risk of death or major disability following perinatal hypoxic-ischemic encephalopathy (HIE); however, many children who experience perinatal HIE still go on to develop personal and behavioral challenges, which can be difficult for caregivers and a public health burden for society. Our objective with this review is to systematically identify and synthesize studies that evaluate associations between perinatal HIE and socioemotional or psychological outcomes.

METHODS

We screened all search-returned journal articles from Cochrane Library, Embase, Medline, PsycINFO, Scopus, and Web of Science from data inception through February 1, 2023. Keywords related to HIE (eg, neonatal encephalopathy, neonatal brain injury) and outcomes (eg, social*, emotion*, behav* problem, psycholog*, psychiatr*) were searched with a predefined search string. We included all observational human studies reporting socioemotional or psychological sequelae of term HIE. Study data were recorded on standardized sheets, and the Newcastle-Ottawa Scale was adapted to assess study quality.

RESULTS

We included 43 studies documenting 3244 HIE participants and 2132 comparison participants. We found statistically significant associations between HIE and social and emotional, behavioral, and psychological and psychiatric deficits throughout infancy, childhood, and adolescence (19 studies). The authors of the included studies also report nonsignificant findings (11 studies) and outcomes without statistical comparison (25 studies).

CONCLUSIONS

Perinatal HIE may be a risk factor for a range of socioemotional and psychological challenges in the short- and long-term. Routine screening, early intervention, and follow-up support may be particularly beneficial to this population.

Higher parental education was associated with good cognitive outcomes in infants with hypoxic-ischaemic encephalopathy

AIM

Predicting neurodevelopmental outcomes in hypoxic-ischaemic encephalopathy (HIE) remains imprecise, despite advanced imaging and neurophysiological tests. We explored the predictive value of socio-economic status (SES).

METHODS

The cohort comprised 93 infants (59% male) with HIE, who had received therapeutic hypothermia. Patients underwent magnetic resonance imaging, and brain injuries were quantified using the Barkovich scoring system. Family SES was self-reported using a questionnaire. Adverse outcomes were defined as mild to severely delayed development with a score of ≤85 in any domain at 2 years of age, based on the Bayley Scales of Infant Development, Second Edition. Data are presented as odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

Multiple regression modelling revealed that higher parental education was strongly associated with good cognitive development, when adjusted for gestational age, serum lactate and brain injuries (OR 2.20, 95% CI 1.16-4.36). The effect size of parental education (β = 0.786) was higher than one score for any brain injury using the Barkovich scoring system (β = -0.356). The literacy environment had a significant effect on cognitive development in the 21 infants who had brain injuries (OR 40, 95% CI 3.70-1352).

CONCLUSION

Parental education and the literacy environment influenced cognitive outcomes in patients with HIE.

Hearing impairment after asphyxia and neonatal encephalopathy: a Norwegian population-based study

The purpose of this study is to evaluate the association between perinatal asphyxia, neonatal encephalopathy, and childhood hearing impairment. This is a population-based study including all Norwegian infants born ≥ 36 weeks gestation between 1999 and 2014 and alive at 2 years (n = 866,232). Data was linked from five national health registries with follow-up through 2019. Perinatal asphyxia was defined as need for neonatal intensive care unit (NICU) admission and an Apgar 5-min score of 4-6 (moderate) or 0-3 (severe). We coined infants with seizures and an Apgar 5-min score < 7 as neonatal encephalopathy with seizures. Infants who received therapeutic hypothermia were considered to have moderate-severe hypoxic-ischemic encephalopathy (HIE). The reference group for comparisons were non-admitted infants with Apgar 5-min score ≥ 7. We used logistic regression models and present data as adjusted odds ratios (aORs) with 95% confidence intervals (CI). The aOR for hearing impairment was increased in all infants admitted to NICU: moderate asphyxia aOR 2.2 (95% CI 1.7-2.9), severe asphyxia aOR 5.2 (95% CI 3.6-7.5), neonatal encephalopathy with seizures aOR 7.0 (95% CI 2.6-19.0), and moderate-severe HIE aOR 10.7 (95% CI 5.3-22.0). However, non-admitted infants with Apgar 5-min scores < 7 did not have increased OR of hearing impairment. The aOR for hearing impairment for individual Apgar 5-min scores in NICU infants increased with decreasing Apgar scores and was 13.6 (95% CI 5.9-31.3) when the score was 0.          Conclusions: An Apgar 5-min score < 7 in combination with NICU admission is an independent risk factor for hearing impairment. Children with moderate-severe HIE had the highest risk for hearing impairment. What is Known: • Perinatal asphyxia and neonatal encephalopathy are associated with an increased risk of hearing impairment. • The strength of the association, and how other co-morbidities affect the risk of hearing impairment, is poorly defined. What is New: • Among neonates admitted to a neonatal intensive care unit (NICU), decreased Apgar 5-min scores, and increased severity of neonatal encephalopathy, were associated with a gradual rise in risk of hearing impairment. • Neonates with an Apgar 5-min score 7, but without NICU admission, did not have an increased risk of hearing impairment.

Therapeutic hypothermia after perinatal asphyxia in Vietnam: medium-term outcomes at 18 months - a prospective cohort study

AIM

To determine neurodevelopmental outcome at 18 months after therapeutic hypothermia for hypoxic-ischaemic encephalopathy (HIE) infants in Vietnam, a low-middle-income country.

METHOD

Prospective cohort study investigating outcomes at 18 months in severely asphyxiated outborn infants who underwent therapeutic hypothermia for HIE in Hanoi, Vietnam, during the time period 2016-2019. Survivors were examined at discharge and at 6 and 18 months by a neonatologist, a neurologist and a rehabilitation physician, who were blinded to the infants' clinical severity during hospitalisation using two assessment tools: the Ages and Stages Questionnaire (ASQ) and the Hammersmith Infant Neurological Examination (HINE), to detect impairments and promote early interventions for those who require it.

RESULTS

In total, 130 neonates, 85 (65%) with moderate and 45 (35%) with severe HIE, underwent therapeutic hypothermia treatment using phase change material. Forty-three infants (33%) died during hospitalisation and in infancy. Among the 87 survivors, 69 (79%) completed follow-up until 18 months. Nineteen children developed cerebral palsy (8 diplegia, 3 hemiplegia, 8 dyskinetic), and 11 had delayed neurodevelopment. At each time point, infants with a normal or delayed neurodevelopment had significantly higher ASQ and HINE scores (p<0.05) than those with cerebral palsy.

CONCLUSION

The rates of mortality and adverse neurodevelopment rate were high and comparable to recently published data from other low-middle-income settings. The ASQ and HINE were useful tools for screening and evaluation of neurodevelopment and neurological function.

Antenatal Magnesium Sulfate Benefits Female Preterm Infants but Results in Poor Male Outcomes

Magnesium sulfate (MagSul) is used clinically to prevent eclamptic seizures during pregnancy and as a tocolytic for preterm labor. More recently, it has been implicated as offering neural protection in utero for at-risk infants. However, evidence is mixed. Some studies found that MagSul reduced the incidence of cerebral palsy (CP) but did not improve other measures of neurologic function. Others did not find any improvement in outcomes. Inconsistencies in the literature may reflect the fact that sex effects are largely ignored, despite evidence that MagSul shows sex effects in animal models of neonatal brain injury. The current study used retrospective infant data to assess differences in developmental outcomes as a function of sex and MagSul treatment. We found that on 18-month neurodevelopmental cognitive and language measures, preterm males treated with MagSul (n = 209) had significantly worse scores than their untreated counterparts (n = 135; p < 0.05). Female preterm infants treated with MagSul (n = 220), on the other hand, showed a cognitive benefit relative to untreated females (n = 123; p < 0.05). No significant effects of MagSul were seen among females on language (p > 0.05). These results have tremendous implications for risk-benefit considerations in the ongoing use of MagSul and may explain why benefits have been hard to identify in clinical trials when sex is not considered.

Growth and developmental outcomes of infants with hypoxic ischemic encephalopathy

Despite advances in obstetric care, hypoxic ischemic encephalopathy (HIE) remains a significant disease burden. We determined the national trends of HIE prevalence, therapeutic hypothermia (TH) use, mortality, and outcomes from 2012 to 2019. This study included term infants diagnosed with HIE between 2012 and 2019 from the National Health Insurance Service database. The prevalence of HIE was 2.4 per 1000 births without significant change during the period. TH was performed in approximately 6.7% of infants with HIE, and the annual variation ranged from 2.4 to 12.5%. The mortality among all term infants with HIE was 4.6%. The mortality rate among infants with HIE and TH significantly declined from 40 to 16.9% during the eight years. Infants with TH had higher mortality, increased use of inhaled nitric oxide, and more invasive ventilator use, indicating greater disease severity in the TH group. Infants with TH also showed significantly poorer outcomes, including delayed development, cerebral palsy, sensorineural hearing loss, and seizure, compared to infants without TH (p < 0.0001). With the increasing application of TH, mortality and developmental outcomes among infants with HIE have been improving in the past eight years in Korea. Further efforts to improve outcomes should be needed.

Perinatal Hypoxic-Ischemic Encephalopathy: Incidence Over Time Within a Modern US Birth Cohort

BACKGROUND

Recent studies suggest that the incidence of perinatal hypoxic-ischemic encephalopathy (HIE) may be increasing in developed countries. However, this observed increase may be due to increased ascertainment and increased treatment with therapeutic hypothermia rather than an increase in disease burden. In a US population-based cross-sectional study, we determined the incidence of perinatal HIE over time.

METHODS

The study population included all 289,793 live-born infants ≥35 weeks gestational age born at 15 Kaiser Permanente Northern California hospitals between 2012 and 2019. Perinatal HIE was defined as the presence of both neonatal acidosis (i.e., cord blood pH < 7 or base deficit ≥10, or base deficit ≥10 on first infant gas) and neonatal encephalopathy confirmed by medical record review. Hospital discharge diagnoses of HIE were determined by extracting International Classification of Disease diagnostic codes for HIE assigned upon hospital discharge.

RESULTS

The population incidence of perinatal HIE was 1.7 per 1000. Although the incidence of perinatal HIE did not change significantly, both hospital discharge diagnoses of HIE and treatment with therapeutic hypothermia increased significantly during the study period. The sensitivity and positive predictive value of a hospital discharge diagnosis of HIE for identifying perinatal HIE confirmed by chart review were 72% and 79%, respectively.

CONCLUSIONS

During the study years, the incidence of perinatal HIE remained stable despite increases in hospital discharge diagnoses of HIE and in the use of therapeutic hypothermia. Our findings underscore the importance of applying stringent diagnostic criteria when diagnosing this complex condition.

Sex differences in neonatal brain injury and inflammation

Neonatal brain injury and associated inflammation is more common in males. There is a well-recognised difference in incidence and outcome of neonatal encephalopathy according to sex with a pronounced male disadvantage. Neurodevelopmental differences manifest from an early age in infancy with females having a lower incidence of developmental delay and learning difficulties in comparison with males and male sex has consistently been identified as a risk factor for cerebral palsy in epidemiological studies. Important neurobiological differences exist between the sexes with respect to neuronal injury which are especially pronounced in preterm neonates. There are many potential reasons for these sex differences including genetic, immunological and hormonal differences but there are limited studies of neonatal immune response. Animal models with induced neonatal hypoxia have shown various sex differences including an upregulated immune response and increased microglial activation in males. Male sex is recognized to be a risk factor for neonatal hypoxic ischemic encephalopathy (HIE) during the perinatal period and this review discusses in detail the sex differences in brain injury in preterm and term neonates and some of the potential new therapies with possible sex affects.

Newborns with Favourable Outcomes after Perinatal Asphyxia Have Upregulated Glucose Metabolism-Related Proteins in Plasma

Hypoxic-ischaemic encephalopathy (HIE) is an important cause of morbidity and mortality globally. Although mild therapeutic hypothermia (TH) may improve outcomes in selected babies, the mechanism of action is not fully understood. A proteomics discovery study was carried out to analyse proteins in the plasma of newborns with HIE. Proteomic analysis of plasma from 22 newborns with moderate-severe HIE that had initially undergone TH, and relative controls including 10 newborns with mild HIE who did not warrant TH and also cord blood from 10 normal births (non-HIE) were carried out using the isobaric Tandem Mass Tag (TMT®) 10plexTM labelling with tandem mass spectrometry. A total of 7818 unique peptides were identified in all TMT10plexTM samples, translating to 3457 peptides representing 405 proteins, after applying stringent filter criteria. Apart from the unique protein signature from normal cord blood, unsupervised analysis revealed several significantly regulated proteins in the TH-treated moderate-severe HIE group. GO annotation and functional clustering revealed various proteins associated with glucose metabolism: the enzymes fructose-bisphosphate aldolase A, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate mutase 1, phosphoglycerate kinase 1, and pyruvate kinase PKM were upregulated in newborns with favourable (sHIE+) outcomes compared to newborns with unfavourable (sHIE-) outcomes. Those with favourable outcomes had normal MR imaging or mild abnormalities not predictive of adverse outcomes. However, in comparison to mild HIE and the sHIE- groups, the sHIE+ group had the additional glucose metabolism-related enzymes upregulated, including triosephosphate isomerase, α-enolase, 6-phosphogluconate dehydrogenase, transaldolase, and mitochondrial glutathione reductase. In conclusion, our plasma proteomic study demonstrates that TH-treated newborns with favourable outcomes have an upregulation in glucose metabolism. These findings may open new avenues for more effective neuroprotective therapy.

Differential Effects of Hypothermia and SZR72 on Cerebral Kynurenine and Kynurenic Acid in a Piglet Model of Hypoxic-Ischemic Encephalopathy

Kynurenic acid (KYNA), an endogenous neuroprotectant with antiexcitotoxic, antioxidant, and anti-inflammatory effects, is synthesized through the tryptophan-kynurenine (KYN) pathway. We investigated whether brain KYN or KYNA levels were affected by asphyxia in a translational piglet model of hypoxic-ischemic encephalopathy (HIE). We also studied brain levels of the putative blood-brain barrier (BBB) permeable neuroprotective KYNA analogue SZR72, and whether SZR72 or therapeutic hypothermia (TH) modified KYN or KYNA levels. KYN, KYNA, and SZR72 levels were determined using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry in five brain regions 24 h after 20 min of asphyxia in vehicle-, SZR72- and TH-treated newborn piglets (n = 6-6-6) and naive controls (n = 4). Endogenous brain KYN levels (median range 311.2-965.6 pmol/g) exceeded KYNA concentrations (4.5-6.0 pmol/g) ~100-fold. Asphyxia significantly increased cerebral KYN and KYNA levels in all regions (1512.0-3273.9 and 16.9-21.2 pmol/g, respectively), increasing the KYN/Tryptophan-, but retaining the KYNA/KYN ratio. SZR72 treatment resulted in very high cerebral SZR72 levels (13.2-33.2 nmol/g); however, KYN and KYNA levels remained similar to those of the vehicle-treated animals. However, TH virtually ameliorated asphyxia-induced elevations in brain KYN and KYNA levels. The present study reports for the first time that the KYN pathway is altered during HIE development in the piglet. SZR72 readily crosses the BBB in piglets but fails to affect cerebral KYNA levels. Beneficial effects of TH may include restoration of the tryptophan metabolism to pre-asphyxia levels.

The Utility and Safety of a Continuous Glucose Monitoring System (CGMS) in Asphyxiated Neonates during Therapeutic Hypothermia

BACKGROUND

The present study was designed to assess the feasibility and reliability of a Continuous Glucose Monitoring System (CGMS) in a population of asphyxiated neonates during therapeutic hypothermia.

METHODS

This non-randomized feasibility study was conducted in the Neonatal Intensive Care Unit (NICU) facilities of Fondazione Policlinico A. Gemelli IRCSS. Infants matching the criteria for hypothermic treatment were included in this study and were connected to the CGMS (Medtronic, Northridge, CA, USA) within the first 12 h of life. Hypoglycemia was defined as a glucose value ≤ 47 mg/dL, and hyperglycemia was defined as a glucose value ≥ 180 mg/dL. Data obtained via the CGMS were compared with those obtained via a point-of-care blood glucometer (GTX).

RESULTS

The two measuring techniques were compared using the Modified Clarke Error Grid (MCEG). Sixteen infants were enrolled. The sensor had an average (standard deviation) duration of 93 (38) h. We collected 119 pairs of glycemia values (CGMVs) from the CGMS vs. GTX measurements. The CGMS detected twenty-five episodes of hypoglycemia and three episodes of hyperglycemia. All the CGMVs indicating hyperglycemia matched with the blood sample taken via the point-of-care glucometer.

CONCLUSIONS

The use of a CGMS would be useful as it could detect more episodes of disglycemia than standard care. Our data show poor results in terms of the accuracy of the CGMS in this particular setting.

A hypothermia mimetic molecule (zr17-2) reduces ganglion cell death, gliosis, and electroretinogram distortion in male rats subjected to perinatal asphyxia

Introduction: Perinatal asphyxia (PA) represents a major problem in perinatology and may cause visual losses, including blindness. We, and others, have shown that hypothermia prevents retinal symptoms associated to PA. In the present work, we evaluate whether a hypothermia mimetic small molecule, zr17-2, has similar effects in the context of PA. Methods: Four experimental groups were studied in male rats: Naturally born rats as controls (CTL), naturally born rats injected s.c. with 50 µL of 330 nmols/L zr17-2 (ZR), animals that were exposed to PA for 20 min at 37°C (PA), and rats that were exposed to PA and injected with zr17-2 (PA-ZR). Forty-five days after treatment, animals were subjected to electroretinography. In addition, morphological techniques (TUNEL, H&E, multiple immunofluorescence) were applied to the retinas. Results: A reduction in the amplitude of the a- and b-wave and oscillatory potentials (OP) of the electroretinogram (ERG) was detected in PA animals. Treatment with zr17-2 resulted in a significant amelioration of these parameters (p < 0.01). In PA animals, a large number of apoptotic cells was found in the GCL. This number was significantly reduced by treatment with the small molecule (p < 0.0001). In a similar way, the thickness of the inner retina and the intensity of GFAP immunoreactivity (gliosis) increased in PA retinas (p < 0.0001). These parameters were corrected by the administration of zr17-2 (p < 0.0001). Furthermore, injection of the small molecule in the absence of PA did not modify the ERG nor the morphological parameters studied, suggesting a lack of toxicity. Discussion: In conclusion, our results indicate that a single s.c. injection of zr17-2 in asphyctic neonates may provide a novel and efficacious method to prevent the visual sequelae of PA.

Comparing Three Methods of Therapeutic Hypothermia Among Transported Neonates with Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) and associated multiorgan injury are significant causes of morbidity and mortality in term and near-term neonates. Therapeutic hypothermia (TH) is the current standard of care for neuroprotection in neonates with HIE. In our experience, the majority of babies born with HIE were found in nontertiary care facilities in our region, where effective methods of cooling during transport to tertiary care centers are desirable. Most centers initiate passive TH at referral hospitals, while active cooling is typically initiated during transport. The objective of this study was to evaluate the effectiveness of three methods of cooling during transport of neonates with HIE in southern Alberta. In this prospective cohort study, 186 neonates with HIE were transported between January 2013 and December 2021. Among the 186 neonates, 47 were passively cooled, 36 actively cooled with gel packs, and 103 cooled with a servo-controlled cooling device. The clinical characteristics were comparable for the three groups, with no difference in adverse events. Fifteen neonates (8%) died and 54 neonates (29%) suffered radiologically determined brain injury. Servo-controlled cooling was found to be superior to other methods in maintaining a target temperature without significant fluctuation during transport and with temperature in the target range on arrival at tertiary care facilities. The rate of overcooling was also lower in the servo-controlled group compared with other groups. There were no statistically significant differences between the groups in relation to mortality and brain MRI changes associated with HIE. Adjusting for GA, 10-minute Apgar score, base excess, HIE stage, and need for intubation during transport, passive cooling increased the odds of temperature fluctuation outside the range by 12-fold and gel pack cooling by 13-fold compared with servo-controlled cooling. The use of servo-controlled TH devices should be the preferred practice wherever feasible. (REB17-1334_REN3).

A narrative review on treatment strategies for neonatal hypoxic ischemic encephalopathy

Background and Objective

Hypoxic-ischemic encephalopathy (HIE) is a leading cause of death and disability worldwide. Therapeutic hypothermia (TH) represents a significant achievement in the translation of scientific research to clinical application, but it is currently the only neuroprotective treatment for HIE. This review aims to revisit the use of TH for HIE and its longitudinal impact on patient outcomes to readers new to the field of HIE. We discuss how emerging therapies address the broader pathophysiology of injury progression in the neonatal brain days to years after HIE.

Methods

We included full articles and book chapters published in English on PubMed with references to "hypoxic ischemic encephalopathy", "birth asphyxia", "therapeutic hypothermia", or "neonatal encephalopathy". We limited our review to outcomes on term infants and to new therapeutics that are in the second phase of clinical trials.

Key Content and Findings

Despite the use of TH for HIE, mortality remains high. Analysis of longitudinal studies reveals a high incidence of ongoing disability even with the implementation of TH. New therapeutics addressing the secondary phase and the less understood tertiary phase of brain injury are in clinical trials as adjunctive treatments to TH to support additional neurological repair and regeneration.

Conclusions

TH successfully improves outcomes after HIE, and it continues to be optimized. Larger studies are needed to understand its use in mild cases of HIE and if certain factors, such as sex, affect long term outcomes. TH primarily acts in the initial phases of injury, while new pharmaceutical therapies target additional injury pathways into the tertiary phases of injury. This may allow for more effective approaches to treatment and improvement of long-term functional outcomes after HIE.

Continuous Fentanyl Infusion in Newborns with Hypoxic-Ischemic Encephalopathy Treated with Therapeutic Hypothermia: Background, Aims, and Study Protocol for Time-Concentration Profiles

Therapeutic hypothermia (TH) is the standard of care for newborns with moderate to severe hypoxic-ischemic encephalopathy (HIE). Discomfort and pain during treatment are common and may affect the therapeutic efficacy of TH. Opioid sedation and analgesia (SA) are generally used in clinical practice, and fentanyl is one of the most frequently administered drugs. However, although fentanyl's pharmacokinetics (PKs) may be altered by hypothermic treatment, the PK behavior of this opioid drug in cooled newborns with HIE has been poorly investigated. The aim of this phase 1 study protocol (Trial ID: FentanylTH; EUDRACT number: 2020-000836-23) is to evaluate the fentanyl time-concentration profiles of full-term newborns with HIE who have been treated with TH. Newborns undergoing TH receive a standard fentanyl regimen (2 mcg/Kg of fentanyl as a loading dose, followed by a continuous infusion-1 mcg/kg/h-during the 72 h of TH and subsequent rewarming). Fentanyl plasma concentrations before bolus administration, at the end of the loading dose, and 24-48-72-96 h after infusion are measured. The median, maximum, and minimum plasma concentrations, together with drug clearance, are determined. This study will explore the fentanyl time-concentration profiles of cooled, full-term newborns with HIE, thereby helping to optimize the fentanyl SA dosing regimen during TH.

Safety of High Dose Erythropoietin Used with Therapeutic Hypothermia as Treatment for Newborn Hypoxic-Ischemic Encephalopathy: Secondary Analysis of the HEAL Randomized Controlled Trial

OBJECTIVE

To assess whether high dose erythropoietin (Epo) treatment of cooled infants with neonatal hypoxic ischemic encephalopathy results in a higher risk of prespecified serious adverse events (SAEs).

STUDY DESIGN

Five hundred infants born at ≥36 weeks of gestation with moderate or severe hypoxic ischemic encephalopathy undergoing therapeutic hypothermia were randomized to Epo or placebo on days 1, 2, 3, 4, and 7. Pretreatment and posttreatment SAEs were compared with adjusted generalized linear models, with posttreatment models adjusted for the presence of a pretreatment SAE. Clinical risk factors and potential mechanisms for SAEs were also examined.

RESULTS

The rate of experiencing at least one posttreatment SAE did not significantly differ between groups (adjusted relative risk [aRR], 95% CI: 1.17, 0.92-1.49); however, posttreatment thrombosis was identified more often in the Epo group (n = 6, 2.3%) than the placebo group (n = 1, 0.4%; aRR, 95% CI: 5.09, 1.32-19.64). The rate of posttreatment intracranial hemorrhage identified at the treatment sites by either ultrasound or magnetic resonance imaging was slightly elevated in the Epo group (n = 61, 24%) but not significantly different from the placebo group (n = 46, 19%; aRR, 95% CI: 1.21, 0.85, 1.72).

CONCLUSIONS

A small increased risk of major thrombotic events was identified in the Epo treatment group.

TRIAL REGISTRATION

NCT02811263.

Use of EEG in neonatal hypoxic-ischemic encephalopathy: A French survey of current practice and perspective for improving health care

OBJECTIVES

Controlled therapeutic hypothermia (CTH) is a standard of care in the management of neonatal hypoxic-ischemic encephalopathy HIE in newborns after 36 weeks of gestational age (WGA) in France. The electroencephalogram (EEG) plays a major role in HIE diagnosis and follow-up. We conducted a French national survey on the current use of EEG in newborn undergoing CTH.

METHODS

Between July and October 2021, an email survey was sent to the heads of the Neonatal intensive care units (NICUs) in metropolitan and overseas French departments and territories.

RESULTS

Out of 67, 56 (83%) of NICUs responded. All of them performed CTH in children born after 36 WGA with clinical and biological criteria of moderate to severe HIE. 82% of the NICUs used conventional EEG (cEEG) before 6 h of life (H6), prior to CTH being performed, to inform decisions about its use. However, half of the 56 NICUs had limited access after regular working hours. 51 of the 56 centers (91%) used cEEG, either short-lasting or continuous monitoring during cooling, while 5 centers conducted only amplitude EEG (aEEG). Only 4 of 56 centers (7%) used cEEG systematically both prior to CTH and for continuous monitoring under CTH.

DISCUSSION

The use of cEEG in the management of neonatal HIE was widespread in NICUs, but with significant disparities when considering 24-hour access. The introduction of a centralized neurophysiological on-call system grouping several NICUs would be of major interest for most centers which do not have the facility of EEG outside working hours.

Development of a neonatal Göttingen Minipig model for dose precision in perinatal asphyxia: technical opportunities, challenges, and potential further steps

Animal models provide useful information on mechanisms in human disease conditions, but also on exploring (patho)physiological factors affecting pharmacokinetics, safety, and efficacy of drugs in development. Also, in pediatric patients, nonclinical data can be critical for better understanding the disease conditions and developing new drug therapies in this age category. For perinatal asphyxia (PA), a condition defined by oxygen deprivation in the perinatal period and possibly resulting in hypoxic ischemic encephalopathy (HIE) or even death, therapeutic hypothermia (TH) together with symptomatic drug therapy, is the standard approach to reduce death and permanent brain damage in these patients. The impact of the systemic hypoxia during PA and/or TH on drug disposition is largely unknown and an animal model can provide useful information on these covariates that cannot be assessed separately in patients. The conventional pig is proven to be a good translational model for PA, but pharmaceutical companies do not use it to develop new drug therapies. As the Göttingen Minipig is the commonly used pig strain in nonclinical drug development, the aim of this project was to develop this animal model for dose precision in PA. This experiment consisted of the instrumentation of 24 healthy male Göttingen Minipigs, within 24 h of partus, weighing approximately 600 g, to allow the mechanical ventilation and the multiple vascular catheters inserted for maintenance infusion, drug administration and blood sampling. After premedication and induction of anesthesia, an experimental protocol of hypoxia was performed, by decreasing the inspiratory oxygen fraction (FiO₂) at 15%, using nitrogen gas. Blood gas analysis was used as an essential tool to evaluate oxygenation and to determine the duration of the systemic hypoxic insult to approximately 1 h. The human clinical situation was mimicked for the first 24 h after birth in case of PA, by administering four compounds (midazolam, phenobarbital, topiramate and fentanyl), frequently used in a neonatal intensive care unit (NICU). This project aimed to develop the first neonatal Göttingen Minipig model for dose precision in PA, allowing to separately study the effect of systemic hypoxia versus TH on drug disposition. Furthermore, this study showed that several techniques that were thought to be challenging or even impossible in these very small animals, such as endotracheal intubation and catheterization of several veins, are feasible by trained personnel. This is relevant information for laboratories using the neonatal Göttingen Minipig for other disease conditions or drug safety testing.

Low Apgar score and need for resuscitation increased the probability of receiving therapeutic hypothermia more strongly than acidosis at birth

AIM

The aim of this study was to investigate how individual markers for birth asphyxia, so-called A criteria, were associated with the probability of receiving therapeutic hypothermia.

METHODS

This population-based cohort study included 1336 live-born singleton term infants with any A criterion in the Stockholm-Gotland Region, Sweden during 2008 to 2014. The Swedish Neonatal Quality Register and National Patient Register were used for data collection. Results were presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

There were 89 infants, 44 boys and 45 girls with mean gestational age 40.5 weeks, who received therapeutic hypothermia. Low Apgar score, aOR 12.44 (95% CI 5.99-25.86), and resuscitation, aOR 9.18 (95% CI 3.77-22.34), were strongly associated with therapeutic hypothermia. A pH <7.0 was less associated with the outcome, aOR 2.02 (95% CI 1.02-4.0). No infant who received therapeutic hypothermia fulfilled the criteria of base deficit ≥16 mmol/L only.

CONCLUSION

A low Apgar score of and/or a need for resuscitation is more relevant for identifying infants eligible for therapeutic hypothermia, compared to other A criteria. This knowledge could be used clinically to identify cases for review and avoid unnecessary monitoring of infants.

Cooling strategies during neonatal transport for hypoxic-ischaemic encephalopathy

AIM

We reviewed the literature on cooling methods during transport of newborn infants with hypoxic-ischaemic encephalopathy (HIE) born in a non-tertiary centre and transferred to a neonatal intensive care unit for therapeutic hypothermia.

METHODS

The electronic databases CENTRAL, MEDLINE, Embase, CINAHL, and Scopus were searched from inception up to 8 March 2022 for studies comparing cooling versus no cooling, active versus passive cooling, and servo-controlled versus non-servo-controlled cooling. Odds ratio and confidence of interval were calculated for dichotomous outcomes and mean difference and confidence interval for continuous outcomes.

RESULTS

The final analysis included 14 studies, 1 randomised and 13 non-randomised, involving 1098 newborn infants. Compared with the other cooling methods, servo-controlled active cooling was more likely to maintain body temperature within the target range of 33°C-34°C on arrival at a neonatal intensive care unit: odds ratio 13.58, 95% confidence interval 4.32-42.66, risk difference 0.33, 95% confidence interval 0.19-0.46; 224 participants; three studies; I² 0%. The certainty of evidence was low. Only five studies reported mortality rates.

CONCLUSION

Servo-controlled active cooling may be the preferred method during transport of newborn infants with HIE. A future area of focus should be long-term neurodevelopmental outcomes after servo-controlled active cooling.

Hypothermia for neonatal hypoxic-ischemic encephalopathy: Retrospective descriptive study of features associated with poor outcome

AIM

To investigate the clinical, laboratory, electrophysiological, and imaging features associated with death or neurological impairment at 1 year of age in term neonates with hypoxic-ischemic encephalopathy (HIE) treated by therapeutic hypothermia (TH).

METHODS

This was a single-center retrospective and descriptive study conducted over a period of 2 years. We included consecutive term newborns with moderate or severe HIE who were treated by TH initiated within the sixth hour after birth and continued for 72 h,. For all patients, brain magnetic resonance imaging (MRI) was performed before the eighth day and a score was established; furthermore, at least two electroencephalograms were recorded.

RESULTS

Among the 33 patients included, 20 neonates had a favorable outcome and 13 had an unfavorable outcome. Early clinical seizures (15% vs. 53.8%, p = 0.047), the persistence of a poor prognosis according to the electroencephalogram pattern after TH (0% vs. 69.2%, p = 0.0001), and an elevated score on the early brain MRI (2 vs. 11, p < 0.001) combined with a high lactate/N-acetyl-aspartate ratio (0.52 vs. 1.33, p = 0.008) on spectroscopy were associated with death and a poor outcome.

CONCLUSION

A combination of tools can help the medical team to establish the most reliable prognosis for these full-term neonates, to guide care, and to inform parents most appropriately and sincerely.

Characteristics and outcomes of neonates with intrapartum asphyxia managed with therapeutic hypothermia in a public tertiary hospital in South Africa

BACKGROUND

In randomized clinical trials, therapeutic hypothermia (TH) has been shown to reduce death and/or moderate-to-severe disability in neonates with hypoxic ischemic encephalopathy (HIE) in high-income countries, while this has not consistently been the case in low-and middle-income countries (LMICs). Many studies reporting on outcomes of neonates with HIE managed with TH are those conducted under controlled study conditions, and few reporting in settings where this intervention is offered as part of standard of care, especially from LMICs. In this study we report on short-term outcomes of neonates with moderate-to-severe HIE where TH was offered as part of standard of care.

OBJECTIVE

To determine characteristics and mortality rate at hospital discharge in neonates with moderate-to-severe HIE.

METHODS

Hospital records of neonates with intrapartum asphyxia were reviewed for clinical findings, management with TH (cooled or non-cooled) and mortality at hospital discharge. Inclusion criteria were birthweight ≥ 1800 g, gestational age ≥ 36 weeks and moderate-to-severe HIE. Comparisons were made between survivors and non-survivors in cooled and/or non-cooled neonates.

RESULTS

Intrapartum asphyxia was diagnosed in 856 neonates, with three having no recorded HIE status; 30% (258/853) had mild HIE, and 595/853 (69%) with moderate-to-severe HIE. The overall incidence of intrapartum asphyxia was 8.8/1000 live births. Of the 595 with moderate-to-severe HIE, three had no records on cooling and 67% (399/592) were cooled. Amongst 193 non-cooled neonates, 126 (67%) had documented reasons for not being cooled with common reasons being a moribund neonate (54.0%), equipment unavailability (11.1%), pulmonary hypertension (9.5%), postnatal age > 6 h on admission (8.7%), and improvement in severity of encephalopathy (8.7%). Overall mortality was 29.0%, being 17.0% and 53.4% in cooled and non-cooled infants respectively. On multivariate analysis, the only factor associated with mortality was severe encephalopathy.

CONCLUSION

Overall mortality in neonates with moderate-to-severe HIE was 29.0% and 17.0% in those who were cooled. Cooling was not offered to all neonates mainly because of severe clinical illness, equipment unavailability and delayed presentation, making it difficult to assess overall impact of this intervention. Prospective clinical studies need to be conducted in LMIC to further assess effect of TH in short and long-term outcomes.