Trends in the incidence and management of hypoxic-ischaemic encephalopathy in the therapeutic hypothermia era: a national population study

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Interventions

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Trial Registration

ClinicalTrials.gov Identifier: NCT01793129.

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.

Improving UK data on avoidable perinatal brain injury: review of data dictionaries and consultation

BACKGROUND

High quality data is important to understanding epidemiology and supporting improvement efforts in perinatal brain injury. It is not clear which data items relevant to brain injury are captured across UK sources of routinely collected data, nor what needs to be done to ensure that those sources are fit for purpose in improving care.

METHODS

We reviewed data dictionaries of four main UK perinatal data sources and consulted a multi-professional group (N = 27) with expertise in neonatal/maternity care, statistics, and clinical negligence.

RESULTS

None of the data sources we reviewed currently captures, on its own, the range of items relevant to brain injury. Data items lack common definitions and ongoing linkage across the different sources. Our consultation identified the need for standardising the definition of avoidable perinatal brain injury, resolving inconsistencies in capturing data, improving linkage of data across existing data sources, and co-designing a strategy for meaningful use of data.

CONCLUSIONS

Limited standardisation and linkage across UK data sources are key problems in using data to guide improvement efforts aimed at reducing risk of avoidable perinatal brain injury. A programme involving co-design with healthcare professionals and families to improve capture and use of data is now needed.

IMPACT

Limited standardisation and linkage across UK data sources currently challenge the use of data as the basis of efforts to reduce risk of avoidable perinatal brain injury. A harmonisation programme involving consultation and co-design with healthcare professionals, families, and other specialists is needed to enable better capture and use of data in this key area. There is need to standardise the definition of avoidable perinatal brain injury, resolve inconsistencies in capturing data, improve linkage of data collected across existing data sources, and co-design a strategy for meaningful use of data.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

IMPACT

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

Pharmacokinetics of 7,8-dihydroxyflavone in neonatal mice with hypoxia-ischemia related brain injury

Introduction

7,8-Dihydroxyflavone (7,8-DHF) is a promising translational therapy in several brain injury models, including the neonatal hypoxia-ischemia (HI) model in mice. However, the neuroprotective effect of 7,8-DHF was only observed in female, but not male, neonatal mice with HI brain injury. It is unknown whether HI-induced physiological changes affect brain distribution of 7,8-DHF differently for male versus female mice. We aimed to evaluate the impact of sex on the pharmacokinetics of 7,8-DHF in plasma and brain neonatal mice following experimentally induced HI brain injury.

Methods

Left-sided HI brain injury was induced in postnatal day 9 (P9) mice, followed by a 5 mg/kg intraperitoneal injection of 7,8-DHF. A liquid chromatography-tandem mass spectrometry method was developed to quantitate the drug concentration in plasma samples, as well as in samples from the left and right brain hemispheres. A nonlinear mixed-effects model was used to analyze the plasma and brain concentration-time data. A semi-quantitative approach was used to evaluate the concentrations of two active O-methylated metabolites of 7,8-DHF (8H7M-flavone and 7H8M-flavone) in both plasma and brain samples.

Results

Our PK analyses show that plasma 7,8-DHF concentrations followed a two-compartment PK model, with more than 95% eliminated by 3 h after the IP injection. Sex was not significantly associated with the PK of 7,8-DHF; however, HI brain injury was associated with a 21% reduction in clearance (p < 0.01). The distribution of 7,8-DHF to the brain was rapid; however, the extent of brain distribution was low with the right and left brain-to-plasma partition coefficients being 8.6% and 9.9%, respectively. Additionally, both O-methylated metabolites of 7,8-DHF were detected in the plasma and brain.

Conclusion

The plasma and brain PK of 7,8-DHF in neonatal mice were similar between males and females. The low extent of 7,8-DHF brain distribution and the potential effects of the active metabolites should be considered in future studies evaluating the therapeutic effects of 7,8-DHF.

Prognostic Indicators of Reorientation of Care in Perinatal Hypoxic-Ischemic Encephalopathy Spectrum

OBJECTIVE

To investigate the clinical, electrographic, and neuroimaging characteristics in neonates with perinatal hypoxic-ischemic encephalopathy who underwent reorientation of care using standardized scoring systems.

STUDY DESIGN

A nested observational substudy within a prospective hypoxic-ischemic encephalopathy cohort was conducted. Group 1 comprised infants whose parents received the medical recommendation for reorientation of care, while group 2 continued to receive standard care. Encephalopathy scores were monitored daily. Amplitude-integrated and continuous-video-integrated electroencephalogram during therapeutic hypothermia were analyzed. Standardized scoring systems for cranial ultrasonography and postrewarming brain magnetic resonance imaging were deployed.

RESULTS

The study included 165 infants, with 35 in group 1 and 130 in Group 2. By day 3, all infants in group 1 were encephalopathic with higher Thompson scores (median 13 [IQR 10-19] vs 0 [IQR 0-3], P < .001). Electrographic background normalization within 48 hours occurred in 3% of group 1 compared with 46% of group 2 (P < .001). Sleep-wake cycling was not observed in group 1 and emerged in 63% of group 2 within the first 72 hours (P < .001). The number of antiseizure medications received was higher in group 1 (median 3 [IQR, 2-4] vs 0 [IQR, 0-1], respectively; P < .001). Group 1 had higher cranial ultrasound injury scores (median 4 [IQR 2-7] vs 1 [IQR 0-1], P < .001) within 48 hours and postrewarming brain magnetic resonance imaging injury scores (median 33 [range 20-51] vs 4 [range 0-28], P < .001).

CONCLUSIONS

Neonates with perinatal hypoxic-ischemic encephalopathy who underwent reorientation of care presented with and maintained significantly more pronounced clinical manifestations, electrographic findings, and near-total brain injury as scored objectively on all modalities.

TRIAL REGISTRATION

Registration of the study cohort: NCT04913324.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of refrigerated gel packs for therapeutic hypothermia in neonatal retrieval: a retrospective cohort study

OBJECTIVE

To determine the efficacy of refrigerated gel packs in achieving and maintaining target temperature in neonates receiving therapeutic hypothermia (TH) for hypoxic ischaemic encephalopathy during neonatal retrieval.

DESIGN

Retrospective cohort study.

SETTING

Paediatric Infant Perinatal Emergency Retrieval, Victoria, Australia.

PATIENTS

200 neonates treated with TH during retrieval between 1 January 2015 and 31 December 2020.

INTERVENTIONS

Active cooling with refrigerated gel packs or passive cooling.

MAIN OUTCOME MEASURES

The primary outcomes were the proportion of neonates who achieved therapeutic cooling rectal temperature (33-34°C) within 6 hours of birth and maintained target temperature range once TH was achieved. Secondary outcomes included need for respiratory support, inotropes, anticonvulsant therapy, sedation and survival at 7 days of life.

RESULTS

200 neonates received TH. Median gestational age was 39 weeks and median birth weight 3300 g. 120 (60%) were actively cooled with refrigerated gel packs and the remainder passively cooled. 121 neonates (61%) reached target temperature within 6 hours and 14 (7%) after 6 hours of birth. Of those who achieved target temperature, 38% were maintained in therapeutic cooling range for the remainder of the retrieval.

CONCLUSIONS

Achieving and maintaining TH during neonatal retrieval with gel packs is challenging. Target temperature was not maintained in most neonates in this study. These findings support existing evidence favouring the use of servo-controlled cooling devices to optimise TH in the retrieval setting.

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.

Mental health of parents with infants in NICU receiving cooling therapy for hypoxic-ischaemic encephalopathy

BACKGROUND

Parents cuddling their babies during intensive care to promote parent-infant bonding is usual practice in the neonatal intensive care unit (NICU). However, babies undergoing cooling therapy and intensive care are not routinely offered parent-infant cuddles due to concerns of impacting the cooling process or intensive care. We developed the CoolCuddle intervention to enable parents to cuddle babies safely during cooling therapy. We investigated whether CoolCuddle impacted parent-infant bonding and parent's mental health.

METHODS

We conducted parental interviews and compared mental health and bonding measures in two cohorts of parents; one with access to CoolCuddle and the other where CoolCuddle was not available.

RESULTS

Ten tertiary NICUs in England and Wales from 2019 to 2023 were involved and 107 families. There were high levels of post-delivery depression amongst all parents. However, at discharge mothers in the CoolCuddle group had significantly less depression, lower EPDS scores, and higher MIBS scores (consistent with better mother-infant bonding) than those where CoolCuddle was not available. All measures appeared similar when re-measured at 8 weeks. Parents reported they were not ready to access psychological support or information whilst on NICU and stressed the need of mental health support following discharge, which was not offered or available.

CONCLUSION

The CoolCuddle intervention was associated with a lower prevalence of depression and enhanced bonding scores for mothers at discharge compared to those who did not cuddle their babies. Parents highlighted increased levels of postnatal depression following the sudden and traumatic admission of their infant to NICU after birth asphyxia.

Association between glycemia and outcomes of neonates with hypoxic-ischemic encephalopathy: a systematic review and meta-analysis

OBJECTIVES

The research aimed to provide the most recent and comprehensive analysis and evidence update comparing outcomes in neonatal encephalopathy (NE) based on different glycemia levels.

PATIENTS AND METHODS

A comprehensive search of Cochrane, PubMed, Embase, Web of Science, CNKI, and Wanfang databases was conducted until September 2023. The purpose was to identify research that examined the effects of hyperglycemia, hypoglycemia, and normoglycemia on NE outcomes. The hyperglycemic, normoglycemic and hypoglycemic group were compared. Outcomes measured were mortality, abnormal MRI, hearing or visual unfavorable outcomes, neurodevelopmental delay, cerebral palsy, and all unfavorable outcomes.

RESULTS

Thirteen literatures comprising 2,427 participants (1,233 with normoglycemia, 835 with hyperglycemia, and 359 with hypoglycemia) were considered. Pooled analysis showed more overall adverse outcomes, higher mortality and worse hearing or visual outcomes in the hyperglycemic and hypoglycemic group compared to the normoglycemic group. There was no notable distinction found in abnormal MRI and cerebral palsy among all groups. The hypoglycemic group exhibited greater neurodevelopmental delay than normoglycemia.

CONCLUSIONS

Maintaining normal blood glucose levels in neonates with NE can help reduce the risk of adverse consequences such as hearing and visual impairment.

Embedding the 'CoolCuddle' intervention for infants undergoing therapeutic hypothermia for hypoxic-ischaemic encephalopathy in NICU: an evaluation using normalisation process theory

OBJECTIVES

Newborn infants exposed to lack of oxygen and blood flow to the brain around birth may develop brain dysfunction (hypoxic-ischaemic encephalopathy-HIE). These infants undergo 72 hours of cooling therapy and most are not held by their parents in the UK. We examined the implementation of 'CoolCuddle', identifying factors that impact embedding of this complex intervention in neonatal intensive care units (NICUs) across England.

DESIGN

Process evaluation and qualitative study using a standard questionnaire and interviews. Normalisation Process Theory (NPT) core constructs were used to assess relevant issues to staff embedding 'CoolCuddle', to discern change over time and different settings. Qualitative interviews provided valuable contextual exploration of implementation.

SETTING AND PARTICIPANTS

Six tertiary NICUs in England. Thirty-seven families with a newborn baby undergoing cooling therapy for HIE were recruited from September 2022 to August 2023; 17 NICU staff Normalisation MeAsure Development (NoMADs) at six NICUs over 6 months were included; 14 neonatal/research nurses from three participating NICUs were interviewed.

INTERVENTION

The family-centred intervention 'CoolCuddle' was developed to enable parents to hold their infant during cooling, without affecting the cooling therapy or intensive care.

OUTCOME MEASURES

NoMAD questionnaires at three timepoints over 6 months and NPT informed qualitative interviews.

RESULTS

NoMAD questionnaires at baseline showed more variation between units, for intervention acceptability, than those at 3 and 6 months. Qualitative data highlighted that staff understood the benefits of CoolCuddle but were apprehensive due to perceived risks involved in moving cooling babies. A rigorous standard operating procedure was flexible enough to incorporate the use of local processes and equipment and provided the relevant procedural knowledge to deliver CoolCuddle safely.

CONCLUSIONS

The CoolCuddle intervention can be implemented safely under the supervision of standard neonatal teams as part of usual practice in diverse NICU settings in England. The importance of having a rigorous standard operating procedure, which can be adapted to support local settings, is highlighted.

TRIAL REGISTRATION NUMBER

ISRCTN10018542; Results: registered on 30 August 2022.

Trends in HIE and Use of Hypothermia in California: Opportunities for Improvement

BACKGROUND AND OBJECTIVES

Hypoxic-ischemic encephalopathy (HIE) is a leading cause of neonatal morbidity and mortality. Therapeutic hypothermia (TH), a proven treatment of moderate-severe HIE, was first used clinically after 2006. We describe trends in HIE diagnosis and use of TH over a 10-year period in California.

METHODS

We identified 62 888 infants, ≥36 weeks gestation, who were cared for in California Perinatal Quality Care Collaborative-participating NICUs between 2010 and 2019, and linked them to birth certificate data. We evaluated trends in HIE diagnosis and use of TH.

RESULTS

Over time, rates of HIE diagnosis increased from 0.6 to 1.7 per 1000 live births, and use of TH increased from 26.5 to 83.0 per 1000 infants. Rates of moderate HIE increased more than mild or severe, although use of TH for mild HIE increased more than for moderate. Of those with moderate-severe HIE, 25% remain untreated. Treatment varied by NICU level of care.

CONCLUSIONS

The rates of HIE and TH increased steadily. Some infants with moderate-severe HIE remain untreated, suggesting a need for ongoing education. Further evaluation of systems of care is needed to assure all qualifying infants are treated.

Hypothermia for Hypoxic-ischemic Encephalopathy: Second-generation Trials to Address Gaps in Knowledge

Multiple randomized controlled trials of hypothermia for moderate or severe neonatal hypoxic-ischemic encephalopathy (HIE) have uniformly demonstrated a reduction in death or disability at early childhood evaluation. These initial trials along with other smaller studies established hypothermia as a standard of care in the neonatal community for moderate or severe HIE. The results of the initial trials have identified gaps in knowledge. This article describes 3 randomized controlled trials of hypothermia (second-generation trials) to address refinement of hypothermia therapy (longer and/or deeper cooling), late initiation of hypothermia (after 6 hours following birth), and use of hypothermia in preterm newborns.

Single-Center Experience with Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy in Infants with <36 Weeks' Gestation

OBJECTIVE

 Hypoxic-ischemic encephalopathy (HIE) is a leading cause of morbidity and mortality in neonates. Therapeutic hypothermia (TH) has improved outcomes and mortality in infants with >36 weeks' gestational age (GA) with moderate-to-severe HIE. There are limited data on the safety and efficacy of TH in preterm infants with HIE. This study describes our experience and examines the safety of TH in neonates with <36 weeks' GA.

STUDY DESIGN

A single-center, retrospective study of preterm neonates born at <36 weeks' GA with moderate-to-severe HIE and treated with TH, compared to a cohort of term neonates with HIE (≥37 weeks' GA), was conducted. The term cohort was matched for degree of background abnormality on electroencephalogram, sex, inborn versus outborn status, and birth year. Medical records were reviewed for pregnancy and delivery complications, need for transfusion, sedation and antiseizure medications, electroencephalography and imaging findings, and in-hospital mortality.

RESULTS

 Forty-two neonates born at <36 weeks' GA with HIE received TH between 2005 and 2022. Data from 42 term neonates were analyzed for comparison. The average GA of the preterm cohort was 34.6 weeks and 39.3 weeks for the term cohort. Apgar scores, degree of acidosis, and need for blood product transfusions were similar between groups. Preterm infants were more likely to require inotropic support (55 vs. 29%, p = 0.026) and hydrocortisone (36 vs. 12%, p = 0.019) for hypotension. The proportion of infants without evidence of injury on magnetic resonance imaging was similar in both groups: 43 versus 50% in preterm and term infants, respectively. No significant difference was found in mortality between groups.

CONCLUSION

 In this single-center cohort, TH in preterm infants appears to be as safe as in term infants, with no significant increase in intracranial bleeds or mortality. Preterm infants more frequently required inotropes and steroids for hypotension. Further research is needed to determine efficacy of TH in preterm infants.

KEY POINTS

· TH is used off-protocol in preterm infants.. · Preterm and term infants have similar mortality.. · Preterm cohort required more inotropic support..

Long-Term Outcomes Following Hypoxic Ischemic Encephalopathy

Hypoxic ischemic encephalopathy (HIE) is the most common cause of neonatal encephalopathy and results in significant morbidity and mortality. Long-term outcomes of the condition encompass impairments across all developmental domains. While therapeutic hypothermia (TH) has improved outcomes for term and late preterm infants with moderate to severe HIE, trials are ongoing to investigate the use of TH for infants with mild or preterm HIE. There is no evidence that adjuvant therapies in combination with TH improve long-term outcomes. Numerous trials of various adjuvant therapies are underway in the quest to further improve outcomes for infants with HIE.

Effect of gestational age on cerebral lesions in neonatal encephalopathy

OBJECTIVE

To determine the risk on brain lesions according to gestational age (GA) in neonates with neonatal encephalopathy.

DESIGN

Secondary analysis of the prospective national French population-based cohort, Long-Term Outcome of NeonataL EncePhALopathy.

SETTING

French neonatal intensive care units.

PATIENTS

Neonates with moderate or severe neonatal encephalopathy (NE) born at ≥34 weeks' GA (wGA) between September 2015 and March 2017.

MAIN OUTCOME MEASURES

The results of MRI performed within the first 12 days were classified in seven injured brain regions: basal ganglia and thalami, white matter (WM), cortex, posterior limb internal capsule, corpus callosum, brainstem and cerebellum. A given infant could have several brain structures affected. Risk of brain lesion according to GA was estimated by crude and adjusted ORs (aOR).

RESULTS

MRI was available for 626 (78.8%) of the 794 included infants with NE. WM lesions predominated in preterm compared with term infants. Compared with 39-40 wGA neonates, those born at 34-35 wGA and 37-38 wGA had greater risk of WM lesions after adjusting for perinatal factors (aOR 4.0, 95% CI (1.5 to 10.7) and ORa 2.0, 95% CI (1.1 to 3.5), respectively).

CONCLUSION

WM is the main brain structure affected in late-preterm and early-term infants with NE, with fewer WM lesions as GA increases. This finding could help clinicians to estimate prognosis and improve the understanding of the pathophysiology of NE.

TRIAL REGISTRATION NUMBER

NCT02676063, ClinicalTrials.gov.

Risk factors for infection and outcomes in infants with neonatal encephalopathy: a cohort study

BACKGROUND

To determine the association between early infection risk factors and short-term outcomes in infants with neonatal encephalopathy following perinatal asphyxia (NE).

METHODS

A retrospective population-based cohort study utilizing the National Neonatal Research Database that included infants with NE admitted to neonatal units in England and Wales, Jan 2008-Feb 2018.

EXPOSURE

one or more of rupture of membranes >18 h, maternal group B streptococcus colonization, chorioamnionitis, maternal pyrexia or antepartum antibiotics.

PRIMARY OUTCOME

death or nasogastric feeds/nil by mouth (NG/NBM) at discharge.

SECONDARY OUTCOMES

organ dysfunction; length of stay; intraventricular hemorrhage; antiseizure medications use.

RESULTS

998 (13.7%) out of 7265 NE infants had exposure to early infection risk factors. Primary outcome (20.3% vs. 23.1%, OR 0.87 (95% CI 0.71-1.08), p = 0.22), death (12.8% vs. 14.0%, p = 0.32) and NG/NBM (17.4% vs. 19.9%. p = 0.07) did not differ between the exposed and unexposed group. Time to full sucking feeds (OR 0.81 (0.69-0.95)), duration (OR 0.82 (0.71-0.95)) and the number of antiseizure medications (OR 0.84 (0.72-0.98)) were lower in exposed than unexposed infants after adjusting for confounders. Therapeutic hypothermia did not alter the results.

CONCLUSIONS

Infants with NE exposed to risk factors for early-onset infection did not have worse short-term adverse outcomes.

IMPACT

Risk factors for early-onset neonatal infection, including rupture of membranes >18 h, maternal group B streptococcus colonization, chorioamnionitis, maternal pyrexia or antepartum antibiotics, were not associated with death or short-term morbidity after cooling for NE. Despite exposure to risk factors for early-onset neonatal infection, infants with NE reached oral feeds earlier and needed fewer anti-seizure medications for a shorter duration than infants with NE but without such risk factors. This study supports current provision of therapeutic hypothermia for infants with NE and any risk factors for early-onset neonatal infection.

Echinatin alleviates inflammation and pyroptosis in hypoxic-ischemic brain damage by inhibiting TLR4/ NF-κB pathway

Hypoxic ischemic encephalopathy (HIE) is a primary cause of neonatal death and disabilities. The pathogenetic process of HIE is closely associated with neuroinflammation. Therefore, targeting and suppressing inflammatory pathways presents a promising therapeutic strategy for the treatment of HIE. Echinatin is an active component of glycyrrhiza, with anti-inflammatory and anti-oxidative properties. It is commonly combined with other traditional Chinese herbs to exert heat-clearing and detoxifying effects. This study aimed to investigate the anti-inflammatory and neuroprotective effects of Echinatin in neonatal rats with hypoxic-ischemic brain damage, as well as in PC12 cells exposed to oxygen-glucose deprivation (OGD). In vivo, Echinatin effectively reduced cerebral edema and infarct volume, protected brain tissue morphology, improved long-term behavioral functions, and inhibited microglia activation. These effects were accompanied by the downregulation of inflammatory factors and pyroptosis markers. The RNA sequencing analysis revealed an enrichment of inflammatory genes in rats with hypoxic-ischemic brain damage, and Protein-protein interaction (PPI) network analysis identified TLR4, MyD88, and NF-κB as the key regulators. In vitro, Echinatin reduced the levels of TLR4 relevant proteins, inhibited nuclear translocation of NF-κB, reduced the expression of downstreams inflammatory cytokines and pyroptosis proteins, and prevented cell membrane destructions. These findings demonstrated that Echinatin could inhibit the TLR4/NF-κB pathway, thereby alleviating neuroinflammation and pyroptosis. This suggests that Echinatin could be a potential candidate for the treatment of HIE.

Effectiveness and Safety of Dexmedetomidine in Neonates With Hypoxic Ischemic Encephalopathy Undergoing Therapeutic Hypothermia

OBJECTIVE

The objective of this study was to evaluate and compare the effectiveness and safety of dexmedetomidine as monotherapy between neonates with mild hypoxic ischemic encephalopathy (HIE) and moderate to severe HIE treated with therapeutic hypothermia (TH).

METHODS

This retrospective study included neonates of gestational age ≥36 weeks with a diagnosis of HIE and undergoing TH between January 2014 and December 2021. Patients were included if they received at least 6 hours of continuous sedation with dexmedetomidine. Baseline characteristics, dose and duration of medication, adverse events, liver and kidney function tests, and hospital course were reviewed.

RESULTS

Of the 97 neonates included, 46 had mild, 42 had moderate, and 9 had severe HIE. Dexmedetomidine was initiated at a median 5 hours of life, and the median infusion duration was 77 (46-87) hours. Fifty-two (53.6%) required at least 1 breakthrough opioid or sedative during the first 24 hours of dexmedetomidine infusion. Overall, 40 patients (41.2%) had at least 1 bradycardia episode with heart rate <80 beats/min and 14 patients (14.4%) had heart rate <70 beats/min. Hypotension was experienced by 7 patients (7.2%). Fifty-two patients (53.6%) were intubated in the delivery room and 33/52 (63.5%) were extubated on day of life 1 during dexmedetomidine infusion.

CONCLUSIONS

Dexmedetomidine as monotherapy was effective and safe sedation for infants with HIE undergoing hypothermia. The most common side effect of dexmedetomidine was bradycardia. -Dexmedetomidine may be considered as first and single agent for neonates with HIE undergoing TH.

The Temporal Relationship between Blood-Brain Barrier Integrity and Microglial Response following Neonatal Hypoxia Ischemia

Blood-brain barrier (BBB) dysfunction and neuroinflammation are key mechanisms of brain injury. We performed a time-course study following neonatal hypoxia-ischemia (HI) to characterize these events. HI brain injury was induced in postnatal day 10 rats by single carotid artery ligation followed by hypoxia (8% oxygen, 90 min). At 6, 12, 24, and 72 h (h) post-HI, brains were collected to assess neuropathology and BBB dysfunction. A significant breakdown of the BBB was observed in the HI injury group compared to the sham group from 6 h in the cortex and hippocampus (p < 0.001), including a significant increase in albumin extravasation (p < 0.0033) and decrease in basal lamina integrity and tight-junction proteins. There was a decrease in resting microglia (p < 0.0001) transitioning to an intermediate state from as early as 6 h post-HI, with the intermediate microglia peaking at 12 h (p < 0.0001), which significantly correlated to the peak of microbleeds. Neonatal HI insult leads to significant brain injury over the first 72 h that is mediated by BBB disruption within 6 h and a transitioning state of the resident microglia. Key BBB events coincide with the appearance of the intermediate microglial state and this relationship warrants further research and may be a key target for therapeutic intervention.

Early Hyperoxemia and 2-year Outcomes in Infants with Hypoxic-ischemic Encephalopathy: A Secondary Analysis of the Infant Cooling Evaluation Trial

OBJECTIVE

To determine the causal relationship between exposure to early hyperoxemia and death or major disability in infants with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We analyzed data from the Infant Cooling Evaluation (ICE) trial that enrolled newborns ≥35 weeks' gestation with moderate-severe HIE, randomly allocated to hypothermia or normothermia. The primary outcome was death or major sensorineural disability at 2 years. We included infants with arterial pO2 measured within 2 hours of birth. Using a directed acyclic graph, we established that markers of severity of perinatal hypoxia-ischemia and pCO2 were a minimally sufficient set of variables for adjustment in a regression model to estimate the causal relationship between arterial pO2 and death/disability.

RESULTS

Among 221 infants, 116 (56%) had arterial pO2 and primary outcome data. The unadjusted analysis revealed a U-shaped relationship between arterial pO2 and death or major disability. Among hyperoxemic infants (pO2 100-500 mmHg) the proportion with death or major disability was 40/58 (0.69), while the proportion in normoxemic infants (pO2 40-99 mmHg) was 20/48 (0.42). In the adjusted model, hyperoxemia increased the risk of death or major disability (adjusted risk ratio 1.61, 95% CI 1.07-2.00, P = .03) in relation to normoxemia.

CONCLUSION

Early hyperoxemia increased the risk of death or major disability among infants who had an early arterial pO2 in the ICE trial. Limitations include the possibility of residual confounding and other causal biases. Further work is warranted to confirm this relationship in the era of routine therapeutic hypothermia.

Neonatal Hypoxic-Ischemic Encephalopathy Spectrum: Severity-Stratified Analysis of Neuroimaging Modalities and Association with Neurodevelopmental Outcomes

OBJECTIVE

To compare hypoxic-ischemic injury on early cranial ultrasonography (cUS) and post-rewarming brain magnetic resonance imaging (MRI) in newborn infants with hypoxic-ischemic encephalopathy (HIE) and to correlate that neuroimaging with neurodevelopmental outcomes.

STUDY DESIGN

This was a retrospective cohort study of infants with mild, moderate, and severe HIE treated with therapeutic hypothermia and evaluated with early cUS and postrewarming MRI. Validated scoring systems were used to compare the severity of brain injury on cUS and MRI. Neurodevelopmental outcomes were assessed at 18 months of age.

RESULTS

Among the 149 included infants, abnormal white matter (WM) and deep gray matter (DGM) hyperechogenicity on cUS in the first 48 hours after birth were more common in the severe HIE group than the mild HIE group (81% vs 39% and 50% vs 0%, respectively; P < .001). In infants with a normal cUS, 95% had normal or mildly abnormal brain MRIs. In infants with severely abnormal cUS, none had normal and 83% had severely abnormal brain MRIs. Total abnormality scores on cUS were higher in neonates with near-total brain injury on MRI than in neonates with normal MRI or WM-predominant injury pattern (adjusted P < .001 for both). In the multivariable model, a severely abnormal MRI was the only independent risk factor for adverse outcomes (OR: 19.9, 95% CI: 4.0-98.1; P < .001).

CONCLUSION

The present study shows the complementary utility of cUS in the first 48 hours after birth as a predictive tool for the presence of hypoxic-ischemic injury on brain MRI.

COHESION: a core outcome set for the treatment of neonatal encephalopathy

BACKGROUND

Heterogeneity in outcomes reported in trials of interventions for the treatment of neonatal encephalopathy (NE) makes evaluating the effectiveness of treatments difficult. Developing a core outcome set for NE treatment would enable researchers to measure and report the same outcomes in future trials. This would minimise waste, ensure relevant outcomes are measured and enable evidence synthesis. Therefore, we aimed to develop a core outcome set for treating NE.

METHODS

Outcomes identified from a systematic review of the literature and interviews with parents were prioritised by stakeholders (n = 99 parents/caregivers, n = 101 healthcare providers, and n = 22 researchers/ academics) in online Delphi surveys. Agreement on the outcomes was achieved at online consensus meetings attended by n = 10 parents, n = 18 healthcare providers, and n = 13 researchers/ academics.

RESULTS

Seven outcomes were included in the final core outcome set: survival; brain injury on imaging; neurological status at discharge; cerebral palsy; general cognitive ability; quality of life of the child, and adverse events related to treatment.

CONCLUSION

We developed a core outcome set for the treatment of NE. This will allow future trials to measure and report the same outcomes and ensure results can be compared. Future work should identify how best to measure the COS.

IMPACT

We have identified seven outcomes that should be measured and reported in all studies for the treatment of neonatal encephalopathy. Previously, a core outcome set for neonatal encephalopathy treatments did not exist. This will help to reduce heterogeneity in outcomes reported in clinical trials and other studies, and help researchers identify the best treatments for neonatal encephalopathy.

Identifying Newborns with Hypoxic-Ischemic Encephalopathy in Hospital Discharge Data: A Validation Study

Hospital discharge databases (HDDs) are increasingly used for research on health of newborns. Linkage between a French population-based cohort of newborns with hypoxic-ischemic encephalopathy (HIE) and national HDD showed that the HIE ICD-10 code was not accurately reported. Our results suggest that HDD should not be used for research on neonatal HIE without prior validation of HIE ICD-10 codes.

Neonatal Hypoxic-Ischemic Encephalopathy and Hypothermia Treatment

Neonatal hypoxic-ischemic encephalopathy (HIE) is an important clinical entity because it is associated with death and long-term disability, including cognitive impairment, cerebral palsy, seizures, and neurosensory deficits. Over the past 40 years, there has been an intensive search to identify therapies to improve the prognosis of neonates with HIE. Hypothermia treatment represents the culmination of laboratory investigations including small and large animal studies, followed by pilot human studies, and, finally, randomized controlled trials to establish efficacy and safety. Clinical trials have demonstrated that hypothermia treatment reduces mortality and improves early childhood outcome among survivors. Hypoxic-ischemic encephalopathy is a multi-system disease process that requires intensive medical support for brain monitoring and monitoring of non-central nervous system organ dysfunction. Treatment must be conducted in a level III or IV neonatal intensive care unit with infrastructure for an integrated approach to care for critically ill neonates. Hypothermia treatment is the first and currently the only therapy to improve outcomes for neonates with HIE and indicates that HIE is modifiable. However, outcomes likely can be improved further. Hypothermia treatment has accelerated investigation of other therapies to combine with hypothermia. It has also stimulated a more intensive approach to brain monitoring, which allows earlier intervention for complications. Finally, HIE and hypothermia treatment negatively influences the psychological state of affected families, and there is growing recognition of the importance of trauma-informed principles to guide medical professionals.

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.

Increase in Standardized Management of Neonates with Hypoxic-Ischemic Encephalopathy Since Implementation of a Patient Register

The Swiss National Asphyxia and Cooling Register was implemented in 2011. This study assessed quality indicators of the cooling process and (short-term) outcomes of neonates with hypoxic-ischemic encephalopathy (HIE) receiving therapeutic hypothermia (TH) longitudinally over time in Switzerland. This is a multicenter national retrospective cohort study of prospectively collected register data. Quality indicators were defined for longitudinal comparison (2011-2014 vs. 2015-2018) of processes of TH and (short-term) outcomes of neonates with moderate-to-severe HIE. Five hundred seventy neonates receiving TH in 10 Swiss cooling centers were included (2011-2018). Four hundred forty-nine (449/570; 78.8%) neonates with moderate-to-severe HIE received TH according to the Swiss National Asphyxia and Cooling Register Protocol. Quality indicators of processes of TH improved in 2015-2018 (compared with 2011-2014): less passive cooling (p = 0.013), shorter time to reach target temperature (p = 0.002), and less over- or undercooling (p < 0.001). In 2015-2018, adherence to performing a cranial magnetic resonance imaging after rewarming improved (p < 0.001), whereas less cranial ultrasounds were performed on admission (p = 0.012). With regard to quality indicators of short-term outcomes, persistent pulmonary hypertension of the neonate was reduced (p = 0.003), and there was a trend toward less coagulopathy (p = 0.063) in 2015-2018. There was no statistically significant change in the remaining processes and outcomes. The Swiss National Asphyxia and Cooling Register is well implemented with good overall adherence to the treatment protocol. Management of TH improved longitudinally. Continuous reevaluation of register data is desirable for quality assessment, benchmarking, and maintaining international evidence-based quality standards.

Evolution of swallowing and feeding abilities of neonates with hypoxic-ischaemic encephalopathy during hospitalisation: A case series

PURPOSE

To describe the evolution of swallowing and feeding abilities of neonates with hypoxic-ischaemic encephalopathy (HIE) during hospitalisation.

METHOD

A longitudinal cohort study was used. Twenty-nine participants (median age 39.0 weeks [IQR = 2.0 weeks]) with mild (n = 7), moderate (n = 19) and severe (n = 3) HIE were included. Clinical swallowing and feeding assessments were conducted at introduction of oral feeds and at discharge using the Neonatal Feeding Assessment Scale (NFAS). Videofluoroscopic swallow studies (VFSS) supplemented the NFAS before discharge.

RESULT

Approximately two thirds of participants showed symptoms of oropharyngeal dysphagia (OPD) during initial NFAS and VFSS. Significantly fewer OPD symptoms occurred at discharge NFAS (p = 0.004). Endurance during non-nutritive sucking (p < 0.001) and nutritive sucking (p < 0.001) significantly improved. Nine participants (31.0%) demonstrated penetration or aspiration. Most aspiration events were silent (60%). Instrumental assessment identified pharyngeal phase dysphagia more effectively than bedside evaluation. High proportions of participants displayed OPD symptoms regardless of HIE severity. The correlation between OPD severity and the length of hospitalisation (p = 0.052) was not significant.

CONCLUSION

All grades of HIE should be considered for early intervention by speech-language pathologists before discharge. Findings may be valuable to neonatal feeding teams.

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.

The Use of Cerebral Near-Infrared Spectroscopy in Neonatal Hypoxic-Ischemic Encephalopathy: A Systematic Review of the Literature

BACKGROUND

Cerebral near-infrared spectroscopy (cNIRS) is a noninvasive technology used to trend cerebral perfusion at the bedside. cNIRS has potential as a valuable tool in the evaluation of infants with suspected hypoxic-ischemic encephalopathy (HIE). Trending cerebral perfusion with cNIRS can provide information regarding cerebral metabolism as HIE is evolving, which may offer insight into the extent of brain injury.

PURPOSE

The purpose of this systematic review is to investigate the use of cNIRS as a neurocritical tool in the management of neonatal HIE by evaluating its ability to detect acute neurological compromise, including acute brain injury and seizure activity, as well as its potential to identify infants at high risk for long-term neurodevelopmental impairment.

METHODS

A literature search was conducted using PubMed, CINAHL, and Web of Science databases to review articles investigating cNIRS technology in the acute management of HIE.

RESULTS

Eight studies were identified and included in this systematic review. Correlations were observed between cNIRS trends and neurological outcomes as later detected by MRI. cNIRS has potential as a bedside neuromonitoring tool in the management of HIE to detect infants at high risk for brain injury.

IMPLICATIONS FOR PRACTICE

Existing research supports the value of trending cNIRS in HIE management. Documented normal cNIRS values for both term and preterm infants in the first few days of life is approximately 60% to 80%. A steadily increasing cNIRS reading above an infant's baseline and a value of more than 90% should prompt further evaluation and concern for significant neurological injury.

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.

Carboxyhaemoglobin levels in infants with hypoxic ischaemic encephalopathy

OBJECTIVES

Hypoxic ischaemic encephalopathy (HIE) is associated with oxidative stress. A potential marker of oxidative damage is carboxyhaemoglobin (COHb) which is the product of the reaction between carbon monoxide and haemoglobin and is routinely assessed on blood gas analysis. Our objective was to test the hypothesis that higher COHb levels would be associated with worse outcomes in infants treated for HIE.

METHODS

A retrospective, observational study was performed of all infants who received whole body hypothermia for HIE at a tertiary neonatal intensive care unit between January 2018 and August 2021. For each participating infant, the highest COHb level per day was recorded for days one, three and five after birth.

RESULTS

During the study period, 67 infants with a median (IQR) gestational age of 40 (38-41) weeks underwent therapeutic hypothermia for HIE. The median (IQR) COHb level on day three was higher in infants without electroencephalographic seizures (1.4 [1.1-1.4] %) compared with infants with seizures (1.1 [0.9-1.3] %, p=0.024). The median (IQR) COHb on day five was higher in infants without MRI brain abnormalities (1.4 [1.2-1.7] %) compared with infants with MRI abnormalities (1.2 [1.0-1.4] %, p=0.032). The COHb level was not significantly different between the nine infants who died compared to the infants who survived.

CONCLUSIONS

COHb levels were higher in infants with HIE without seizures and in those with normal MRI brain examinations. We suggest that carbon monoxide has a potential protective role in HIE.

Early Neuroprotective Effects of Bovine Lactoferrin Associated with Hypothermia after Neonatal Brain Hypoxia-Ischemia in Rats

Neonatal hypoxic-ischemic (HI) encephalopathy (HIE) in term newborns is a leading cause of mortality and chronic disability. Hypothermia (HT) is the only clinically available therapeutic intervention; however, its neuroprotective effects are limited. Lactoferrin (LF) is the major whey protein in milk presenting iron-binding, anti-inflammatory and anti-apoptotic properties and has been shown to protect very immature brains against HI damage. We hypothesized that combining early oral administration of LF with whole body hypothermia could enhance neuroprotection in a HIE rat model. Pregnant Wistar rats were fed an LF-supplemented diet (1 mg/kg) or a control diet from (P6). At P7, the male and female pups had the right common carotid artery occluded followed by hypoxia (8% O2 for 60') (HI). Immediately after hypoxia, hypothermia (target temperature of 32.5-33.5 °C) was performed (5 h duration) using Criticool®. The animals were divided according to diet, injury and thermal condition. At P8 (24 h after HI), the brain neurochemical profile was assessed using magnetic resonance spectroscopy (1H-MRS) and a hyperintense T2W signal was used to measure the brain lesions. The mRNA levels of the genes related to glutamatergic excitotoxicity, energy metabolism and inflammation were assessed in the right hippocampus. The cell markers and apoptosis expression were assessed using immunofluorescence in the right hippocampus. HI decreased the energy metabolites and increased lactate. The neuronal-astrocytic coupling impairments observed in the HI groups were reversed mainly by HT. LF had an important effect on astrocyte function, decreasing the levels of the genes related to glutamatergic excitotoxicity and restoring the mRNA levels of the genes related to metabolic support. When combined, LF and HT presented a synergistic effect and prevented lactate accumulation, decreased inflammation and reduced brain damage, pointing out the benefits of combining these therapies. Overall, we showed that through distinct mechanisms lactoferrin can enhance neuroprotection induced by HT following neonatal brain hypoxia-ischemia.

Early-onset neonatal seizures: lidocaine toxicity as a rare differential diagnosis to hypoxic ischaemic encephalopathy

A term newborn girl presented with apnoea and seizures at approximately 20 min of life following an uneventful vaginal delivery. She required admission to the Neonatal Intensive Care Unit following intubation and was commenced on conventional ventilation. Her mother had received a local lidocaine injection for an episiotomy prior to delivery. Initial investigations confirmed electrographic seizures for which she received an anticonvulsant with successful termination of seizure activity. Investigations for hypoxic injury, intracranial trauma, structural brain abnormalities, metabolic disorders and infection were unremarkable. Her blood lidocaine level was subsequently found to be elevated, confirming lidocaine toxicity as the cause of presentation. She demonstrated clinical improvement with no evidence of complications at time of discharge or on early follow-up.

Predictive value of the Thompson score for short-term adverse outcomes in neonatal encephalopathy

BACKGROUND

To explore the predictive value of the Thompson score during the first 4 days of life for estimating short-term adverse outcomes in neonatal encephalopathy.

METHODS

This observational study evaluated infants with neonatal encephalopathy (≥36 weeks of gestation) registered in a multicenter cohort of cooled infants in Japan. The Thompson score was evaluated at 0-24, 24-48, 48-72, and 72-90 h of age. Adverse outcomes included death, survival with respiratory impairment (requiring tracheostomy), or survival with feeding impairment (requiring gavage feeding) at discharge.

RESULTS

Of the 632 infants, 21 (3.3%) died, 59 (9.3%) survived with respiratory impairment, and 113 (17.9%) survived with feeding impairment. The Thompson score throughout the first 4 days accurately predicted death, respiratory impairment, or feeding impairment. The 72-90 h score showed the highest accuracy. A cutoff of ≥15 had a sensitivity of 0.85 and specificity of 0.92 for death or respiratory impairment, while a cutoff of ≥14 had a sensitivity of 0.71 and a specificity of 0.92 for death, respiratory or feeding impairment.

CONCLUSION

A high Thompson score during the first 4 days of life, especially at 72-90 h could thus be useful for estimating the need for prolonged life support.

IMPACT

The Thompson score on days 1-4 of age was useful in predicting death and respiratory or feeding impairments. The 72-90 h Thompson score showed the highest predictive capability. Owing to the rarity of withdrawal of life-sustaining treatment in Japan, 43% of infants with persistent severe encephalopathy with a Thompson score of ≥15 at 72-90 h of age could regain spontaneous breathing, be extubated, and survive without tracheostomy. Meanwhile, approximately 50% of infants who survived without tracheostomy required gavage feeding. Our results could provide useful information for clinical decision making regarding infants with persistent severe encephalopathy.

Hypoxic-Ischemic Encephalopathy: Changing Outcomes Across the Spectrum

Neonatal hypoxic-ischemic encephalopathy (HIE) is a leading cause of death and neurodevelopmental impairment in neonates. Therapeutic hypothermia (TH) is the only established effective therapy and randomized trials affirm that TH reduces death and disability in moderate-to-severe HIE. Traditionally, infants with mild HIE were excluded from these trials due to the perceived low risk for impairment. Recently, multiple studies suggest that infants with untreated mild HIE may be at significant risk of abnormal neurodevelopmental outcomes. This review will focus on the changing landscape of TH, the spectrum of HIE presentations and their neurodevelopmental outcomes.

Glycemia and Neonatal Encephalopathy: Outcomes in the LyTONEPAL (Long-Term Outcome of Neonatal Hypoxic EncePhALopathy in the Era of Neuroprotective Treatment With Hypothermia) Cohort

OBJECTIVES

To assess in newborns with neonatal encephalopathy (NE), presumptively related to a peripartum hypoxic-ischemic event, the frequency of dysglycemia and its association with neonatal adverse outcomes.

STUDY DESIGN

We conducted a secondary analysis of LyTONEPAL (Long-Term Outcome of Neonatal hypoxic EncePhALopathy in the era of neuroprotective treatment with hypothermia), a population-based cohort study including 545 patients with moderate-to-severe NE. Newborns were categorized by the glycemia values assessed by routine clinical care during the first 3 days of life: normoglycemic (all glycemia measurements ranged from 2.2 to 8.3 mmol/L), hyperglycemic (at least 1 measurement >8.3 mmol/L), hypoglycemic (at least 1 measurement <2.2 mmol/L), or with glycemic lability (measurements included at least 1 episode of hypoglycemia and 1 episode of hyperglycemia). The primary adverse outcome was a composite outcome defined by death and/or brain lesions on magnetic resonance imaging, regardless of severity or location.

RESULTS

In total, 199 newborns were categorized as normoglycemic (36.5%), 74 hypoglycemic (13.6%), 213 hyperglycemic (39.1%), and 59 (10.8%) with glycemic lability, based on the 2593 glycemia measurements collected. The primary adverse outcome was observed in 77 (45.8%) normoglycemic newborns, 37 (59.7%) with hypoglycemia, 137 (67.5%) with hyperglycemia, and 40 (70.2%) with glycemic lability (P < .01). With the normoglycemic group as the reference, the aORs and 95% 95% CIs for the adverse outcome were significantly greater for the group with hyperglycemia (aOR 1.81; 95% CI 1.06-3.11).

CONCLUSIONS

Dysglycemia affects nearly two-thirds of newborns with NE and is independently associated with a greater risk of mortality and/or brain lesions on magnetic resonance imaging.

TRIAL REGISTRATION

NCT02676063.

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.

Trends of neonatal hypoxic-ischemic encephalopathy prevalence and associated risk factors in the United States, 2010 to 2018

BACKGROUND

Despite recent advances in perinatal care, neonatal hypoxic-ischemic encephalopathy remains one of the most common causes of neonatal morbidity and mortality. The trends for prevalence and mortality of neonatal hypoxic-ischemic encephalopathy have not been examined in the era of therapeutic hypothermia in the United States.

OBJECTIVE

This study aimed to determine (1) the overall and gestational age-specific (35-36, ≥37, and >42 weeks) trends of hypoxic-ischemic encephalopathy prevalence and use of therapeutic hypothermia, (2) the trends of mortality in association with hypoxic-ischemic encephalopathy, (3) the confounding variables associated with hypoxic-ischemic encephalopathy, and (4) the clinical outcomes of neonates with hypoxic-ischemic encephalopathy.

STUDY DESIGN

This study used National Inpatient Sample datasets from 2010 to 2018. Moreover, the study included infants with a gestational age of ≥35 weeks with a documented hypoxic-ischemic encephalopathy diagnosis (mild, moderate, severe, or unspecified). We calculated trends in hypoxic-ischemic encephalopathy prevalence and the use of therapeutic hypothermia using chi-squared testing. Furthermore, this study used logistic regression models to control for confounders.

RESULTS

A total of 32,180,617 infants were included, of which 31,249,100 were term (gestational age of ≥37 weeks) and 931,517 were late preterm (gestational age of 35-36 weeks). Hypoxic-ischemic encephalopathy prevalence slightly increased from 0.093% in 2010-2012 to 0.097% in 2016-2018 (P=.01) in term infants and did not significantly change in late preterm infants (P=.20). There were 6235 term infants (20.8%) and 449 late preterm infants (21.1%) with hypoxic-ischemic encephalopathy who were managed with therapeutic hypothermia. The use of therapeutic hypothermia in both term and late preterm infants has increased over the years (P<.01). The mortality rate with hypoxic-ischemic encephalopathy decreased over time from 11.5% to 12.3% between 2010 to 2012, and from 8.3% to 10.6% betweenn 2016 to 2018 (P<.01). The factors with the strongest association with hypoxic-ischemic encephalopathy were placental infarction or insufficiency (odds ratio, 144; 95% confidence interval, 134-157), placental abruption (odds ratio, 101; 95% confidence interval, 91-112), cord prolapse (odds ratio, 74; 95% confidence interval, 65-84), and maternal anemia (odds ratio, 26; 95% confidence interval, 20-37).

CONCLUSION

Hypoxic-ischemic encephalopathy prevalence in neonates essentially remained the same at 1 per 1000 live births. The use of therapeutic hypothermia increased, and the mortality rate decreased in infants with hypoxic-ischemic encephalopathy. The identification of hypoxic-ischemic encephalopathy-associated factors should promote increased vigilance to optimize newborn outcomes.

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.

Feeding children with neurodisability: challenges and practicalities

Nutritional management for children with neurodisability can be challenging and there are an increasing number of children at risk of malnutrition. Management involves healthcare professionals in community and hospital working together with the family with the aim of optimising nutrition and quality of life. Feeding difficulties can be the result of physical causes like lack of oromotor coordination, discomfort associated with reflux oesophagitis or gastrointestinal dysmotility. Non-physical causes include parental/professional views towards feeding, altered perception of pain and discomfort, extreme sensitivity to certain textures and rigidity of feeding schedule associated with artificial feeding. Estimating nutritional needs can be difficult and is affected by comorbidities including epilepsy and abnormal movements, severity of disability and mobility. Defining malnutrition is difficult as children with neurodisability reflect a wide spectrum with disparate growth patterns and body composition and auxology is less reliable and less reproducible. Management involves selecting the type and method of feeding best suited for the patient. As artificial feeding can place a significant burden of care any decision-making should be, as much as possible, in concurrence with the family. Symptom management sometimes requires pharmacological interventions, but polypharmacy is best avoided. The article aims to discuss the pathways of identifying children at risk of malnutrition and available management options with a strong emphasis on working as a clinical team with the child and family.

Neuroprotection for hypoxic-ischemic encephalopathy: Contributions from the neonatal research network

Therapeutic hypothermia (TH) is now well established as the standard of care treatment for moderate to severe neonatal encephalopathy secondary to perinatal hypoxic ischemic encephalopathy (HIE) in infants ≥36 weeks gestation in high income countries. The Neonatal Research Network (NRN) contributed greatly to the study of TH as a neuroprotectant with three trials now completed in infants ≥36 weeks gestation and the only large randomized-controlled trial of TH in preterm infants now in the follow-up phase. Data from the first NRN TH trial combined with data from other large trials of TH affirm the safety and neuroprotective qualities of TH and highlight the importance of providing TH to all infants who qualify. In this review we will highlight the findings of the three NRN trials of TH in the term infant population and the secondary analyses that continue to inform the care of patients with HIE.

Differences in standardized neonatal encephalopathy exam criteria may impact therapeutic hypothermia eligibility

BACKGROUND

Therapeutic hypothermia (TH) is routinely provided to those with moderate or severe neonatal encephalopathy (NE). Subtle differences exist in the standardized exams used to define NE severity. We aimed to assess if an infant's TH eligibility status differed if they were evaluated using either the NICHD/Neonatal Research Network's (NICHD-NRN) or TOBY/British Association of Perinatal Medicine's (TOBY-BAPM) neurological exam.

METHODS

Encephalopathic infants ≥36 weeks with evidence of perinatal asphyxia and complete documentation of the neurological exam &lt;6 h of age were included. TH eligibility using the NICHD-NRN and TOBY-BAPM criteria was determined based upon the documented exams.

RESULTS

Ninety-one encephalopathic infants were included. Despite good agreement between the two exams (κ = 0.715, p &lt; 0.001), TH eligibility differed between them (p &lt; 0.001). A total of 47 infants were deemed eligible by at least one method-46 using NICHD-NRN and 35 using TOBY-BAPM. Of the 12 infants eligible per NICHD-NRN, but ineligible per TOBY-BAPM, two developed electrographic seizures and seven demonstrated hypoxic-ischemic cerebral injury.

CONCLUSIONS

Both the NICHD-NRN and TOBY-BAPM exams are evidence-based. Despite this, there is a significant difference in the number of infants eligible for TH depending on which exam is used. The NICHD-NRN exam identifies a greater proportion as eligible.

IMPACT

There are subtle differences in the NICHD-NRN and TOBY-BAPM's encephalopathy exams used to determine eligibility for TH. This results in a significant difference in the proportion of infants determined to be eligible for TH depending on which encephalopathy exam is used. The NICHD-NRN encephalopathy exam identifies more infants as being eligible for TH than the TOBY-BAPM encephalopathy exam. This may result in different rates of cooling depending on which evidence-based neurological exam for evaluation of encephalopathy a center uses.

Variations in practices and outcomes of neonates with hypoxic ischemic encephalopathy treated with therapeutic hypothermia across tertiary NICUs in Canada

OBJECTIVE

To characterize variations in practices and outcomes for neonates with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH) across Canadian tertiary Neonatal Intensive Care Units (NICUs).

STUDY DESIGN

Retrospective study of neonates admitted for HIE and treated with TH in 24 tertiary NICUs from the Canadian Neonatal Network, 2010-2020. The two primary outcomes of mortality before discharge and MRI-detected brain injury were compared across NICUs using adjusted standardized ratios (SR) with 95% CI.

RESULTS

Of the 3261 neonates that received TH, 367 (11%) died and 1033 (37%) of the 2822 with MRI results had brain injury. Overall, rates varied significantly across NICUs for mortality (range 5-17%) and brain injury (range 28-51%). Significant variations in use of inotropes, inhaled nitric oxide, blood products, and feeding during TH were identified (p values < 0.01).

CONCLUSION

Significant variations exist in practices and outcomes of HIE neonates treated with hypothermia across Canada.

The effects of caffeine following hypoxic-ischemic encephalopathy: a systematic review of animal studies

BACKGROUND

Caffeine is believed to be neuroprotective in preterm and term infants, despite the conflicting data on its effects on the developing brain in animal models. We aimed to conduct a systematic review with meta-analysis assessing the effects of caffeine on the prevention and treatment of neurological morbidity caused by hypoxic-ischemic encephalopathy (HIE) in preclinical studies.

METHODS

Randomized and non-randomized control studies in animal models of HIE reporting caffeine administration within the first ten days of life were included. Primary outcomes were behavioral tests that served as surrogates for cognition, memory, motor coordination, and gait; secondary outcomes pertained to structural neurologic changes. Screening for inclusion, risk of bias and data extraction were performed independently by two authors.

RESULTS

Seven studies met inclusion: 5 studies were conducted in rats and 2 in mice. All studies were performed in full-term animals, and the majority of studies used animals of both sexes (5/7). In six studies, caffeine was administered intraperitoneally to the pups, while in the remaining study, it was delivered via the drinking water of the lactating dams. The doses of caffeine ranged from 5-20 mg/kg; in one study, caffeine dosage was 0.3 mg/L in the drinking water of lactating dam. The mortality rate was reported only in three studies. Caffeine had a positive effect on overall functional outcome (SDM 0.92(95%CI 0.25 to 1.59)). Animals treated with caffeine performed better on Morris water maze and rotarod tests (SDM -1.39(95%CI -0.36 to -2.41)) and (SDM 1.03(95%CI 0.03 to 2.04)), respectively. Caffeine treated animals performed worse on open field test compared to the controls (SDM -1.11(95%CI -3.01 to 0.80)). The overall quality of the included studies was limited.

CONCLUSIONS

Early caffeine exposure in preclinical rodent models of HIE is associated with improved selective functional and neurological outcomes, although the certainty of the evidence is limited. To validate the therapeutic efficacy of caffeine as a neuroprotective adjuvant, there is a need to explore its effects in larger animal models, which will help guide the design of relevant clinical trials.