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

Feasibility of Minimal Enteral Nutrition During Therapeutic Hypothermia for Perinatal Asphyxia: A Five-Year Multicenter Experience from South India

Limited evidence shows minimal enteral nutrition (MEN) during therapeutic hypothermia (TH) in neonates to be feasible and have benefits of shorter time to full-feeds. This study aimed to assess the feasibility of MEN during TH. MEN was initiated after 12 h if there were no altered aspirates, abdominal distension, and inotrope requirement. The authors retrospectively analyzed the records from May 2017 to April 2022. The number of episodes of feed intolerance and the length of hospital stay were the key outcomes. A total of 99 neonates were fed during cooling. MEN could be initiated at a median duration (IQR) of 24 (24-30) h. There were 9 (9%) neonates with feed intolerance during TH. None had necrotizing enterocolitis. Ninety-two (93%) neonates were discharged, with a median hospital stay (IQR) of 9 d (6-15). Hence, MEN during TH is feasible and provides a rationale for future controlled trials.

Adequacy of sedation analgesia to support the comfort of neonates undergoing therapeutic hypothermia and its impact on short-term neonatal outcomes

Objectives

We aimed to evaluate (1) whether sedation analgesia (SA) used during therapeutic hypothermia (TH) was efficient to support the wellbeing of neonates with hypoxic-ischemic encephalopathy, (2) the SA level and its adjustment to clinical pain scores, and (3) the impact of inadequate SA on short-term neonatal outcomes evaluated at discharge.

Methods

This was an observational retrospective study performed between 2011 and 2018 in two level III centers in Alsace, France. We analyzed the wellbeing of infants by using the COMFORT-Behavior (COMFORT-B) clinical score and SA level during TH, according to which we classified infants into four groups: those with excess SA, adequate SA, lack of SA, and variability of SA. We analyzed the variations in doses of SA and their justification. We also determined the impact of inadequate SA on neonatal outcomes at discharge by multivariate analyses with multinomial regression, with adequate SA as the reference.

Results

A total of 110 patients were included, 89 from Strasbourg university hospital and 21 from Mulhouse hospital. The COMFORT-B score was assessed 95.5% of the time. Lack of SA was mainly found on the first day of TH (15/110, 14%). In all, 62 of 110 (57%) infants were in excess of SA over the entire duration of TH. Most dose variations were related to clinical pain scores. Inadequate SA was associated with negative short-term consequences. Infants with excess of SA had a longer duration of mechanical ventilation [mean ratio 1.46, 95% confidence interval (CI), 1.13-1.89, p = 0.005] and higher incidence of abnormal neurological examination at discharge (odds ratio 2.61, 95% CI, 1.10-6.18, p = 0.029) than infants with adequate SA.

Discussion

Adequate SA was not easy to achieve during TH. Close and regular monitoring of SA level may help achieve adequate SA. Excess of SA can be harmful for newborns with hypoxic-ischemic encephalopathy who are undergoing TH.

Therapeutic hypothermia is associated with changes in prognostic value of general movements

BACKGROUND AND AIMS

General movements (GMs) have been recognized as the most accurate clinical tools for predicting cerebral palsy (CP). This study aimed to compare the type and prognostic value of abnormal GMs in infants with hypoxic ischemic encephalopathy treated or not with therapeutic hypothermia (TH).

MATERIALS AND METHODS

This was a single-center retrospective study. We compared GMs of 55 cooled term infants versus 30 non-cooled term infants with hypoxic ischemic encephalopathy (HIE) and their motor outcome at 24 months of age. We also included data regarding early brain MRI scans.

RESULTS

Rates of cerebral palsy was 5.4% and 46.7% in cooled and non-cooled infants respectively (p < 0.001). None of cooled infants showed cramped-synchronized GMs, whereas among non-cooled infants the cramped-synchronized pattern was present in 17.2% and 20% of infants at 1 and 3 months of age respectively. Hypokinesis was never seen in cooled infants and it was present in 23.3% of non-cooled ones. Absent fidgety correlated with CP in 14% and 73% of cooled and non-cooled infants respectively. At brain MRI cooled infants had fewer and less severe cerebral lesions compared to non-cooled infants (p = 0.003).

CONCLUSIONS

Abnormal GMs are reduced in infants treated with TH. Hypokinesis and cramped-synchronized GMs are not observed in cooled infants and the associations between absent fidgety movements and CP it is largely abolished. TH is associated with changes in prognostic value of GMs.

Time series analysis of non-invasive hemodynamic monitoring data in neonates with hypoxic-ischemic encephalopathy

Background and aims

Hemodynamic instability is common in neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). Rewarming is a critical period and non-invasive circulatory monitoring may help guide cardiovascular supportive therapy. The aim of the study was to provide a comprehensive analysis of cardiac function parameters during TH and its relation to neurodevelopmental outcome.

Methods

In a prospective, observational study, 26 neonates with moderate-severe HIE were enrolled, born between 2016 and 2019. A hemodynamic monitor based on electrical velocimetry (ICON, Osypka Medical GmbH, Berlin, Germany) was used. Heart rate (HR), stroke volume (SV), cardiac output (CO) data were recorded continuously throughout TH and rewarming. Neurological outcome was assessed at 2 years of age using the Bayley Scales of Infant Development II. edition. Favorable outcome was defined as >70 points on both the psychomotor and mental scales. Time-series analysis was used and features of cardiac function were described to perform logistic regression modeling for outcome prediction.

Results

Fourteen (54%) patients had favorable and 12 (46%) had adverse outcome. Data collection started from median [IQR] of 11.8 [7.0; 24.3] hours (h) of life and lasted until 84.0. [81.8; 87.0] h. During TH, the mean HR of the favorable outcome group was significantly lower than that of the adverse outcome group (86 ± 13/min vs. 104 ± 18/min, p = 0.01). During rewarming HR increased similarly in both groups. SV was unaffected by rewarming, and showed a slowly increasing trend. SV of the favorable outcome group was significantly higher compared to the adverse outcome group (1.55 ± 0.23 ml/kg vs. 1.29 ± 0.30 ml/kg, p = 0.035). In line with this, CO was similar in both groups (136 ± 27 ml/kg/min vs. 134 ± 36 ml/kg/min), and a significant 25% increase in CO was observed during rewarming. Based on multiple regression modeling, HR during TH was independently associated with neurological outcome (p = 0.023).

Conclusion

Based on continuous hemodynamic monitoring, patients with adverse outcome have lower SV and higher HR to achieve similar CO to patients with favorable outcome during TH. HR during hypothermia is independently associated with the neurodevelopmental outcome.

Neonatal Cerebral Sinovenous Thrombosis Post–Therapeutic Hypothermia in Perinatal Asphyxia: A Case Report

Cerebral sinovenous thrombosis (CSVT) is an uncommon condition in neonates and often leads to adverse neurodevelopmental outcomes. A high index of suspicion for CSVT is mandated for asphyxiated infants, especially following therapeutic hypothermia (TH). Magnetic resonance venography can assist in the early detection of CSVT in suspected cases. Timely initiation of anticoagulation therapy prevents thrombus propagation and allows recanalization at around 6 to 12 weeks. Long-term follow-up is essential as cognitive impairment, motor dysfunctions, and epilepsy are common complications. Herein, we describe the clinical course of a term infant who developed CSVT in the first week of life following TH for perinatal asphyxia, its management strategies, and short-term follow-up till infancy.

Outcome at early school age and adolescence after hypothermia-treated hypoxic-ischaemic encephalopathy: an observational, population-based study

OBJECTIVE

We aimed to describe long-term outcomes following hypoxic-ischaemic encephalopathy (HIE) treated with therapeutic hypothermia (TH).

DESIGN

Prospective, population-based observational study.

SETTING

Tertiary level neonatal intensive care units and neonatal outpatient clinic, Karolinska University Hospital, Stockholm, Sweden.

PATIENTS

Sixty-six infants treated with TH due to HIE between 2007 and 2009.

INTERVENTIONS

At 6-8 years and 10-12 years of age, children were assessed using a standardised neurological examination, the Movement Assessment Battery for Children, Second Edition (MABC-2) and the Wechsler Intelligence Scales for Children IV/V. Parents completed the Five-to-Fifteen (FTF) questionnaire.

MAIN OUTCOME MEASURES

Adverse outcome among survivors was defined as cerebral palsy (CP), epilepsy, hearing or visual impairment, full-scale IQ (FSIQ) below 85, attention deficit disorder with/without hyperactivity, autism spectrum disorder or developmental coordination disorder.

RESULTS

Mortality was 12%. Seventeen per cent of survivors developed CP. Mean FSIQ was normal in children without major neuromotor impairment. Assessment in early adolescence revealed emerging deficits in 26% of children with a previously favourable outcome. The proportion of children exhibiting executive difficulties increased from 7% to 19%. This was reflected also by a significantly increased proportion of children with an FTF score >90th percentile compared with norms in early adolescence. The proportion of children with an MABC-2 score ≤5th percentile was also significantly increased compared with norms.

CONCLUSIONS

Survivors without major neuromotor impairment have normal intelligence. The incidence of executive difficulties appears to be increased in this patient population. More subtle difficulties may go undetected at early school-age.

Fentanyl analgesia in asphyxiated newborns treated with therapeutic hypothermia

INTRODUCTION

Therapeutic hypothermia is the standard care for asphyxiated newborns. Discomfort and pain during treatment are common and may affect therapeutic efficacy of hypothermia. Opioid analgosedation is commonly used in the clinical setting, but its effects in the cooled newborns is poorly investigated.

OBJECTIVE

The aim of this study was to assess the safety of fentanyl analgosedation during therapeutic hypothermia, by evaluating severe adverse effects and possible correlation with the neurodevelopmental outcome.

METHODS

We analyzed asphyxiated newborns treated with hypothermia receiving fentanyl intravenous infusion (years 2013-2018). Severe neurodevelopmental outcome was defined as cerebral palsy or Griffith's developmental quotient <70 or major sensorineural deficit. Severe brain lesions were defined as cortical or/and basal ganglia extensive involvement.

RESULTS

Fentanyl cumulative dose was variable (61.7 ± 18.5 µg/kg; range 34.3-120.3 µg/kg) among 45 enrolled patients. Respiratory depression was recorded in 13.3% cases of 30 spontaneously breathing patients. Severe brain lesions and severe neurodevelopmental disability were found in 24.4 and 11.1% of all included cases, respectively. Higher cumulative fentanyl dose was not associated with poor outcome.

CONCLUSIONS

Fentanyl treatment during therapeutic hypothermia does not negatively affect the neurodevelopmental outcome, thus on the contrary, it may contribute to ameliorate neuroprotection in the asphyxiated cooled newborns.

Electroencephalogram Background Predicts Time to Full Oral Feedings in Hypoxic-Ischemic Encephalopathy

OBJECTIVE

Infants with a history of neonatal hypoxic-ischemic encephalopathy (HIE) are at risk for oral motor dysfunction. Previous studies have associated the need for gastrostomy tube at neonatal intensive care unit discharge with brainstem injury on magnetic resonance imaging (MRI). However, the factors associated with time to full oral feeds in this population have not been previously described. This study aimed to study factors associated with time to full oral feeds in this population.

STUDY DESIGN

This is a single-center, retrospective study that examined these factors using Cox regression.

RESULTS

A total of 150 infants who received therapeutic hypothermia from 2011 to 2017 were included in this study. The single clinical factor significantly associated with time to full oral feeds was the severity of background abnormality on electroencephalogram in the first 24 hours of age (severe vs. mild 95% confidence interval [CI]: 0.34-0.74; moderate vs. mild 95% CI: 0.19-0.45). Brainstem injury on MRI was the factor most highly associated with need for gastrostomy tube placement (p = 0.028), though the overall incidence of need for gastrostomy tube feeds in this population was low (5%).

CONCLUSION

These findings may help clinicians counsel families on what to expect in neonates with HIE and make decisions on the need for and timing to pursue gastrostomy tube in this population.

KEY POINTS

· The overall incidence of the need for assisted feeding at NICU discharge is low in this population.. · MRI brainstem injury was most highly associated with need for gastrostomy tube placement.. · Worsening severity of background abnormality on EEG was associated with longer time to oral feeds..

A novel scoring system (YASHMA) predicting brain injury in asphyxiated newborns

BACKGROUND

Hypoxic-ischemic encephalopathy is a complication of adverse intrapartum events and birth asphyxia resulting in brain injury and mortality in late preterm and term newborns.

OBJECTIVES

In this study, we aimed to predict brain damage on magnetic resonance imaging (MRI) with a new scoring system.

METHODS

Yieldly And Scorable Holistic Measuring of Asphyxia (YASHMA) is generated for detection of brain injury in asphyxiated newborns. Total scores were calculated according to scores of birth weight, gestation weeks, APGAR scores at first and fifth minutes, aEEG patterns and epileptic status of patients. The major outcome of the scoring system was to determine correlation between poor scores and neonatal brain injury detected on MRI.

RESULTS

In hypothermia group with brain injury, low gestational weeks and lowest APGAR scores, abnormal aEEG findings were statistically different from others. YASHMA scores were statistically significant with high sensitivity, specificity, AUC and 95% confidence interval values.

CONCLUSIONS

YASHMA scoring system is feasible and can be suggestive for detecting brain injury in low-income countries.

Cerebral injuries in neonatal encephalopathy treated with hypothermia: French LyTONEPAL cohort

BACKGROUND

Hypothermia is widely used for infants with hypoxic-ischemic neonatal encephalopathy but its impact remains poorly described at a population level. We aimed to describe brain imaging in infants born at ≥36 weeks' gestation, with moderate/severe encephalopathy treated with hypothermia.

METHODS

Descriptive analysis of brain MRI and discharge neurological examination for infants included in the French national multicentric prospective observational cohort LyTONEPAL.

RESULTS

Among 575 eligible infants, 479 (83.3%) with MRI before 12 days of life were included. MRI was normal for 48.2% (95% CI 43.7-52.8). Among infants with brain injuries, 62.5% (95% CI 56.2-68.5) had damage to more than one structure, 19.8% (95% CI 15.0-25.3) showed a pattern-associating injuries of basal ganglia/thalami (BGT), white matter (WM) and cortex. Overall, 68.4% (95% CI 62.0-74.3) of infants with normal MRI survived with a normal neurological examination. The rate of death was 15.4% (95% CI 12.3-19.0), predominantly for infants with the combined BGT, cortex, and/or WM injuries.

CONCLUSIONS

Among infants with neonatal encephalopathy treated with hypothermia, two-thirds of those with normal MRI survived with a normal neurological examination at discharge. When present, brain injuries often involved more than one structure.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov (NCT02676063).

IMPACT

In this multicentric cohort of infants with neonatal encephalopathy (LYTONEPAL) two-thirds survived with normal MRI and neurological examination at discharge. In total, 10% of newborns showed a pattern associating injuries of the basal ganglia-thalami, white matter, and cortex, which was correlated with a high risk of death at discharge. The evolution of MRI techniques and sequences in the era of hypothermia calls for a revisiting of imaging protocol in neonatal encephalopathy, especially for the timing. The neurological examination did not give evidence of brain injuries, thus questioning the reproducibility of the clinical exam or the neonatal brain functionality.

Association Between Early EEG Background and Outcomes in Infants With Mild HIE Undergoing Therapeutic Hypothermia

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) occurs in 1-4:1000 live births. Although neonates with moderate-severe HIE have been studied over several decades, newborns with mild HIE remain understudied, including seizure occurrence, electroencephalography (EEG) characteristics, and outcome.

METHODS

We conducted a retrospective cohort study of neonates ≥35 weeks of gestation with mild HIE who underwent therapeutic hypothermia to correlate the early EEG background pattern with clinical course and outcomes.

RESULTS

Of the included 29 neonates, 10 infants had a moderately to severely abnormal EEG background and 19 had either a normal or a mildly abnormal background. Those with moderately to severely abnormal background also had more multiorgan dysfunction (90% vs 42%, P = 0.02) and a higher incidence of subdural and intraventricular hemorrhages (80% vs 26%, P = 0.02). The overall seizure incidence was 20.7% and was significantly higher in newborns with more severely abnormal background compared to neonates with less abnormal background (50% vs 5%; P = 0.01; relative risk, 9.5; 95% confidence interval, 1.28-70.6). Seizure onset was between 11 and 63 hours of life. Regardless of the EEG background pattern, seizures were brief with an overall low seizure burden. None of the newborns with normal or mildly abnormal background had a new onset of seizures after 24 hours of recording or developed epilepsy during infancy.

CONCLUSIONS

In neonates with mild HIE, early moderately to severely abnormal EEG background is common and strongly associated with an increased risk for seizures.

Polygraphic EEG Can Identify Asphyxiated Infants for Therapeutic Hypothermia and Predict Neurodevelopmental Outcomes

Background: Neonatal encephalopathy due to perinatal asphyxia is one of the leading causes of neonatal death and morbidity worldwide. The neurodevelopmental outcomes of asphyxiated neonates have considerably improved after therapeutic hypothermia (TH). The current challenge is to identify all newborns with encephalopathy at risk of cerebral lesions and subsequent disability within 6 h of life and who may be within the window period for treatment with TH. This study evaluated the neurodevelopmental outcomes in surviving asphyxiated neonates who did and did not receive TH, based on clinical and polygraphic electroencephalographic (p-EEG) criteria. Methods: The study included 139 asphyxiated newborns divided into two groups: 82 who received TH and 57 who were not cooled. TH was administered to asphyxiated newborns (gestational age ≥ 35 weeks, birth weight ≥ 1800 g) with encephalopathy of any grade and moderate-to-severe p-EEG abnormalities or seizures. Neurodevelopmental outcomes between the groups at 24 months of life and the risk factors for severe outcomes were assessed. Results: Severe neurodevelopmental impairment occurred in 10 (7.2%) out of the 139 enrolled neonates. Nine out of the 82 cooled neonates (11.0%) had severe neurodevelopmental impairment. All but one neonate (98.2%) who did not receive TH had normal outcomes. The multivariate logistic regression analysis showed that abnormal p-EEG patterns (OR: 27.6; IC: 2.8-267.6) and general movements (OR: 3.2; IC: 1.0-10.0) were significantly associated with severe neurodevelopmental impairment (area under ROC curve: 92.7%). Conclusion: The combination of clinical and p-EEG evaluations in hypoxic-ischemic encephalopathy contributed to a more accurate selection of patients treated with therapeutic hypothermia. When administered to infants with moderate to severe p-EEG abnormalities, TH prevents approximately 90% of severe neurodevelopmental impairment after any grade of hypoxic-ischemic encephalopathy.

Early Troponin I Levels in Newborns Undergoing Therapeutic Hypothermia for Hypoxic Ischemic Encephalopathy and Residual Encephalopathy at Discharge

OBJECTIVE

Elevation of serum troponin I has been reported in newborns with hypoxic ischemic encephalopathy (HIE), but it is diagnostic and prognostic utility for newborn under 6 hours is not clear. Study the predictive value of early serum troponin I levels in newborns with HIE undergoing therapeutic hypothermia (TH) for persistent residual encephalopathy (RE) at discharge.

STUDY DESIGN

Retrospective chart review of newborns admitted with diagnosis of HIE to neonatal intensive care unit (NICU) for TH over a period of 3 years. Troponin levels were drawn with the initial set of admission laboratories while initiating TH. Newborns were followed up during hospital course and stratified into three groups based on predischarge examination and their electrical encephalography and cranial MRI findings: Group 1: no RE, Group 2: mild-to-moderate RE, and Group 3: severe RE or needing assisted medical technology or death. Demographic and clinical characteristics including troponin I levels were compared in each group.

RESULTS

Out of 104 newborns who underwent TH, 65 infants were in Group 1, 26 infants in Group 2, and 13 newborns in Group 3. All groups were comparable in demographic characteristics. There was a significant elevation of serum troponin in group 2 (mild-to-moderate RE) and group 3 (severe RE) as compared with group 1 (no RE). Receiver operator curve analysis for any RE (groups 2 and 3) compared with group 1 (no RE as control) had 0.88 (0.81-0.95) area under curve, p < 0.001. A cut-off level of troponin I ≥0.12 µg/L had a sensitivity of 77% and specificity of 78% for diagnosis of any RE, positive predictive value of 68%, and a negative predictive value of 84%.

CONCLUSION

In newborns undergoing TH for HIE, the elevation of troponin within 6 hours of age predicts high risk of having RE at discharge.

KEY POINTS

· Troponin I elevation is a biomarker of myocardial ischemia in adults and children.. · Myocardial ischemia may be part of multi-organ injury in neonatal HIE.. · Early elevation of troponin I level may correlate with the severity of neonatal HIE and predict residual encephalopathy in newborn at discharge from initial hospitalization..

Core outcomes in neonatal encephalopathy: a qualitative study with parents

OBJECTIVE

To identify the outcomes considered important to parents or caregivers of infants diagnosed with neonatal encephalopathy, hypoxic ischaemic encephalopathy or birth asphyxia in high-income and low- to middle-income countries (LMiCs), as part of the outcome-identification process in developing a core outcome set (COS) for the treatment of neonatal encephalopathy.

DESIGN

A qualitative study involving 25 semistructured interviews with parents or other family members (caregivers) of infants who were diagnosed with, and treated for, neonatal encephalopathy, hypoxic ischaemic encephalopathy or birth asphyxia.

SETTING

Interviews were conducted in high-income countries (HiCs) (n=11) by Zoom video conferencing software and in LMiCs (n=14) by phone or face to face.

FINDINGS

Parents identified 54 outcomes overall, which mapped to 16 outcome domains. The domains identified were neurological outcomes, respiratory outcomes, gastrointestinal outcomes, cardiovascular outcomes, motor development, cognitive development, development (psychosocial), development (special senses), cognitive development, development (speech and social), other organ outcomes, survival/living outcomes, long-term disability, hospitalisation, parent-reported outcomes and adverse events.

CONCLUSIONS

This study provides insight into the outcomes that parents of infants diagnosed with neonatal encephalopathy have identified as the most important, to be considered in the process of developing a COS for the treatment of neonatal encephalopathy. We also provide description of the processes employed to ensure the inclusion of participants from LMiCs as well as HiCs.

Feasibility of EEG Phase-Amplitude Coupling to Stratify Encephalopathy Severity in Neonatal HIE Using Short Time Window

Goal: It is challenging to clinically discern the severity of neonatal hypoxic ischemic encephalopathy (HIE) within hours after birth in time for therapeutic decision-making for hypothermia. The goal of this study was to determine the shortest duration of the EEG based PAC index to provide real-time guidance for clinical decision-making for neonates with HIE. Methods: Neonates were recruited from a single-center Level III NICU between 2017 and 2019. A time-dependent, PAC-frequency-averaged index, tPACm, was calculated to characterize intrinsic coupling between the amplitudes of 12−30 Hz and the phases of 1−2 Hz oscillation from 6-h EEG data at electrode P3 during the first day of life, using different sizes of moving windows including 10 s, 20 s, 1 min, 2 min, 5 min, 10 min, 20 min, 30 min, 60 min, and 120 min. Time-dependent receiver operating characteristic (ROC) curves were generated to examine the performance of the accurate window tPACm as a neurophysiologic biomarker. Results: A total of 33 neonates (mild-HIE, n = 15 and moderate/severe HIE, n = 18) were enrolled. Mixed effects models demonstrated that tPACm between the two groups was significantly different with window time segments of 3−120 min. By observing the estimates of group differences in tPACm across different window sizes, we found 20 min was the shortest window size to optimally distinguish the two groups (p < 0.001). Time-varying ROC showed significant average area-under-the-curve of 0.82. Conclusions: We demonstrated the feasibility of using tPACm with a 20 min EEG time window to differentiate the severity of HIE and facilitate earlier diagnosis and treatment initiation.

Comparative analysis of background EEG activity based on MRI findings in neonatal hypoxic-ischemic encephalopathy: a standardized, low-resolution, brain electromagnetic tomography (sLORETA) study

Background

It is important to assess the degree of brain injury and predict long-term outcomes in neonates diagnosed with hypoxic-ischemic encephalopathy (HIE). However, routine studies, including magnetic resonance imaging (MRI) and conventional encephalography (EEG) or amplitude-integrated EEG (aEEG), have their own limitations in terms of availability and accuracy of evaluation. Recently, quantitative EEG (qEEG) has been shown to improve the predictive reliability of neonatal HIE and has been further refined with brain mapping techniques.

Methods

We investigated background EEG activities in 29 neonates with HIE who experienced therapeutic hypothermia, via qEEG using a distributed source model. MRI images were evaluated and classified into two groups (normal-to-mild injury vs moderate-to-severe injury), based on a scoring system. Non-parametric statistical analysis using standardized low-resolution brain electromagnetic tomography was performed to compare the current density distribution of four frequency bands (delta, theta, alpha, and beta) between the two groups.

Results

Electrical neuronal activities were significantly lower in the moderate-to-severe injury group compared with the normal-to-mild injury group. Background EEG activities in moderate-to-severe HIE were most significantly reduced in the temporal and parietal lobes. Quantitative EEG also revealed a decrease in background activity at all frequency bands, with a maximum in decrease in the delta component. The maximum difference in current density was found in the inferior parietal lobule of the right parietal lobe for the delta frequency band.

Conclusions

Our study demonstrated quantitative and topographical changes in EEG in moderate-to-severe neonatal HIE. They also suggest possible implementation and evaluation of conventional EEG and aEEG in neonatal HIE. The findings have implications as biomarkers in the assessment of neonatal HIE.

An Updated Overview of MRI Injuries in Neonatal Encephalopathy: LyTONEPAL Cohort

BACKGROUND

Brain magnetic resonance imaging (MRI) is a key tool for the prognostication of encephalic newborns in the context of hypoxic-ischemic events. The purpose of this study was to finely characterize brain injuries in this context.

METHODS

We provided a complete, descriptive analysis of the brain MRIs of infants included in the French national, multicentric cohort LyTONEPAL.

RESULTS

Among 794 eligible infants, 520 (65.5%) with MRI before 12 days of life, grade II or III encephalopathy and gestational age ≥36 weeks were included. Half of the population had a brain injury (52.4%); MRIs were acquired before 6 days of life among 247 (47.5%) newborns. The basal ganglia (BGT), white matter (WM) and cortex were the three predominant sites of injuries, affecting 33.8% (n = 171), 33.5% (n = 166) and 25.6% (n = 128) of participants, respectively. The thalamus and the periventricular WM were the predominant sublocations. The BGT, posterior limb internal capsule, brainstem and cortical injuries appeared more frequently in the early MRI group than in the late MRI group.

CONCLUSION

This study described an overview of brain injuries in hypoxic-ischemic neonatal encephalopathy. The basal ganglia with the thalamus and the WM with periventricular sublocation injuries were predominant. Comprehensive identification of brain injuries in the context of HIE may provide insight into the mechanism and time of occurrence.

Therapeutic hypothermia in neonatal hypoxic encephalopathy: A systematic review and meta-analysis

Background

Therapeutic hypothermia (TH) is regarded as the most efficacious therapy for neonatal hypoxic encephalopathy. However, limitations in previous systematic reviews and the publication of new data necessitate updating the evidence. We conducted this up-to-date systematic review to evaluate the effects of TH in neonatal encephalopathy on clinical outcomes.

Methods

In this systematic review and meta-analysis, we searched Medline, Cochrane Library, Embase, LIVIVO, Web of Science, Scopus, CINAHL, major trial registries, and grey literature (from inception to October 31, 2021), for randomized controlled trials (RCT) comparing TH vs normothermia in neonatal encephalopathy. We included RCTs enrolling neonates (gestation ≥35 weeks) with perinatal asphyxia and encephalopathy, who received either TH (temperature ≤34°C) initiated within 6 hours of birth for ≥48 hours, vs no cooling. We excluded non-RCTs, those with delayed cooling, or cooling to >34°C. Two authors independently appraised risk-of-bias and extracted data on mortality and neurologic disability at four time points: neonatal (from randomization to discharge/death), infancy (18-24 months), childhood (5-10 years), and long-term (>10 years). Other outcomes included seizures, EEG abnormalities, and MRI findings. Summary data from published RCTs were pooled through fixed-effect meta-analysis.

Results

We identified 36 863 citations and included 39 publications representing 29 RCTs with 2926 participants. Thirteen studies each had low, moderate, and high risk-of-bias. The pooled risk ratios (95% confidence interval, CI) were as follows: neonatal mortality: 0.87 (95% CI = 0.75, 1.00), n = 2434, I² = 38%; mortality at 18-24 months: 0.88 (95% CI = 0.78, 1.01), n = 2042, I² = 51%; mortality at 5-10 years: 0.81 (95% CI = 0.62, 1.04), n = 515, I² = 59%; disability at 18-24 months: 0.62 (95% CI = 0.52, 0.75), n = 1440, I² = 26%; disability at 5-10 years: 0.68 (95% CI = 0.52, 0.90), n = 442, I² = 3%; mortality or disability at 18-24 months: 0.78 (95% CI = 0.72, 0.86), n = 1914, I² = 54%; cerebral palsy at 18-24 months: 0.63 (95% CI = 0.50, 0.78), n = 1136, I² = 39%; and childhood cerebral palsy: 0.63 (95% CI = 0.46, 0.85), n = 449, I² = 0%. Some outcomes showed significant differences by study-setting; the risk ratio (95% CI) for mortality at 18-24 months was 0.79 (95% CI = 0.66,0.93), n = 1212, I² = 7% in high-income countries, 0.67 (95% CI = 0.41, 1.09), n = 276, I² = 0% in upper-middle-income countries, and 1.18 (95% CI = 0.94, 1.47), n = 554, I² = 75% in lower-middle-income countries. The corresponding pooled risk ratios for ‘mortality or disability at 18-24 months’ were 0.77 (95% CI = 0.69, 0.86), n = 1089, I² = 0%; 0.56 (95% CI = 0.41, 0.78), n = 276, I² = 30%; and 0.92 (95% CI = 0.77, 1.09), n = 549, I² = 86% respectively. Trials with low risk of bias showed risk ratio of 0.97 (95% CI = 0.80, 1.16, n = 1475, I² = 62%) for neonatal mortality, whereas trials with higher risk of bias showed 0.71 (95% CI = 0.55, 0.91), n = 959, I² = 0%. Likewise, risk ratio for mortality at 18-24 months was 0.96 (95% CI = 0.83, 1.13), n = 1336, I² = 58% among low risk-of-bias trials, but 0.72 (95% CI = 0.56, 0.92), n = 706, I² = 0%, among higher risk of bias trials.

Conclusions

Therapeutic hypothermia for neonatal encephalopathy reduces neurologic disability and cerebral palsy, but its effect on neonatal, infantile and childhood mortality is uncertain. The setting where it is implemented affects the outcomes. Low(er) quality trials overestimated the potential benefit of TH.

Prognostic Value of Various Diagnostic Methods for Long-Term Outcome of Newborns After Hypoxic-Ischemic Encephalopathy Treated With Hypothermia

INTRODUCTION

Prediction of outcome in newborns with hypoxic-ischemic encephalopathy (HIE) has been modulated by hypothermia treatment (HT). We assessed the predictive value of diagnostic methods commonly used in neonates with HIE for short-term neurodevelopmental outcome and long-term neurological outcome.

MATERIALS AND METHODS

This longitudinal cohort study followed up 50 term newborns who underwent HT after HIE between July 2006 and August 2015, until preschool age. We estimated sensitivity and specificity for short-term neurodevelopmental outcome at 18 months and long-term neurological outcome at five years based on Amiel-Tison Neurological Assessment (ATNA), electroencephalography (EEG), and magnetic resonance imaging (MRI) performed in the neonatal period.

RESULTS

The accuracy of all neonatal methods tested was higher for long-term neurological outcome compared to the predictive accuracy for short-term neurodevelopmental outcome at 18-24 months. Sensitivity and specificity in predicting unfavorable long-term neurological outcome were: MRI (sensitivity 1.0 [95%CI 0.96-1.0]; specificity 0.91 [95%CI 0.86-1.0]), EEG (sensitivity 0.94 [95%CI 0.71-1.0]; specificity 1.0 [95% CI 0.89-1.0]), and ATNA (sensitivity 0.94 [95%CI 0.71-1.0]; specificity 0.91 [95%CI 0.76-0.98]).

CONCLUSION

MRI is a powerful predictor of long-term neurological outcome when performed in the first week after HIE in HT treated infants, as are EEG and ATNA performed in the second or third week postnatally.

Advances in the Prevention and Treatment of Neonatal Hypothermia in Early Birth

Neonates are vulnerable to hypothermia in the early postnatal period due to a low temperature environment, physiological function, and many other factors. In this article, the definition, occurrence status, related factors, hazards, and prevention strategies of neonatal hypothermia are reviewed. The interventions for hypothermia are mainly achieved through three processes, that is, intervention in the delivery room before and after birth, intervention on the way from the delivery room to the neonatal intensive care unit (NICU), and intervention after arrival at the NICU. Rewarming is the main intervention measure after the occurrence of hypothermia and slow rewarming is advocated, based on related studies of early neonatal cold injury syndrome and mild hypothermia treatment of hypoxic-ischemic encephalopathy. Rapid rewarming has been proposed in recent years but remains controversial. There are no detailed guidelines yet for rewarming for early neonatal hypothermia, and there is no precise definition of "rapid rewarming" and "slow rewarming" in terms of the rewarming rate.

Therapeutic Hypothermia in Transport Permits Earlier Treatment Regardless of Transfer Distance

OBJECTIVE

Therapeutic hypothermia (TH) is currently the only effective therapy available to improve outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) and has maximal effect when initiated within 6 hours of birth. Neonates affected by HIE are commonly born outside of cooling centers and transport is a barrier to timely initiation. In this study, we sought to determine if the initiation of servo-controlled TH in transport allowed neonates to reach target temperature earlier, without a significant delay in the transfer process, for both local and long-distance transport.

STUDY DESIGN

In this single-center cohort study of neonates referred to a level IV neonatal intensive care unit for TH, we determined the chronologic age at which target temperature was reached for those cooled in transport. Short-term outcome measures were assessed, including survival, incidence of electrographic seizures, discharge feeding method, and length of hospitalization.

RESULTS

In a study population of 85 neonates, those receiving TH during transport (n = 23), achieved target temperature (33-34°C) 77 minutes sooner (230 ± 71 vs. 307 ± 79 minutes of life (MOL); p < 0.001). Locally transported neonates (<15 miles) achieved target temperature 69 minutes earlier (215 ± 48 vs. 284 ± 74 MOL; p < 0.01). TH during long-distance transports allowed neonates to reach target temperature 81 minutes sooner (213 ± 85 vs. 294 ± 79 MOL; p < 0.01). Infants who were cooled in transport discharged 4 days earlier (13.7 ± 8 vs. 17.8 ± 13 days; p = 0.18) and showed a significantly higher rate of oral feeding at discharge (95 vs. 71%; p = 0.03).

CONCLUSION

For those starting TH in transport, time to target temperature was decreased. In our cohort, cooling in transport was associated with improved short-term outcomes, although additional studies are needed to correlate these findings with long-term outcomes.

KEY POINTS

· Therapeutic hypothermia started during transport allows shorter time to target temperature.. · Transfer was minimally delayed by starting cooling in transport.. · Cooling in transport was associated with increased rate of oral feeding at hospital discharge..

New Horizons in Mild Hypoxic-ischemic Encephalopathy: A Standardized Algorithm to Move past Conundrum of Care

Hypoxic-ischemic encephalopathy (HIE) presents clinically with a neonatal encephalopathy (NE) whereby the mild spectrum is difficult to classify immediately after birth. For decades trials have focused exclusively on infants with moderate-severe HIE s, as these infants were easier to identify after birth and had the highest risk of adverse outcomes. Twenty years after those trials, the PRIME study finally solved the first part of the conundrum by providing a definition of mild HIE in the first 6 hours. There is strong biological plausibility and preclinical evidence supporting the efficacy of therapeutic hypothermia (TH) but there is a lack of comparative clinical data to establish the risk-benefit in mild HIE. The fundamental question of how best to manage mild HIE remains unanswered. This review will summarize (1) the evidence that neonates with mild HIE are at significant risk for adverse outcomes, (2) the gaps/controversies in management, and (3) an algorithm of care is proposed to ensure standardized management of mild HIE and the direction of future trials.

The association between early-onset sepsis and neonatal encephalopathy

OBJECTIVE

We evaluated the association between early-onset sepsis and neonatal encephalopathy in a low-middle-income setting.

METHODS

We undertook a retrospective study in newborns with gestational age ≥35 weeks and/or birth weight ≥2500 grams, diagnosed with neonatal encephalopathy. Early-onset sepsis was defined as culture-confirmed sepsis or probable sepsis.

RESULTS

Of 10,182 hospitalised newborns, 1027 (10.1%) were diagnosed with neonatal encephalopathy, of whom 52 (5.1%) had culture-confirmed and 129 (12.5%) probable sepsis. The case fatality rate for culture-confirmed sepsis associated neonatal encephalopathy was threefold higher compared to neonatal encephalopathy without sepsis (30.8% vs. 10.5%, p < 0.001). Predictors of mortality for culture-confirmed sepsis associated neonatal encephalopathy included severe neonatal encephalopathy (aOR 6.51, 95%CI: 1.03-41.44) and seizures (aOR 10.64, 95%CI: 1.05-107.39).

CONCLUSION

In this setting, 5% of neonatal encephalopathy cases was associated with culture-confirmed sepsis and a high case fatality rate.

Alterations in motor functional connectivity in Neonatal Hypoxic Ischemic Encephalopathy

BACKGROUND

Neonatal hypoxic-ischemic encephalopathy (HIE) is the result of global hypoxic-ischemic brain injury in neonates due to asphyxia during birth and is one of the most common causes of severe, long-term neurologic deficits in children. Methods: Resting state fMRI (rs-fMRI) was used to assess potential functional disruptions in the primary and association motor areas in HIE neonates (n = 16) compared to healthy controls (n = 11).

RESULTS

Results demonstrate reduced intra-hemispheric resting state functional connectivity (rs-FC) between primary motor regions (upper extremity and facial motor regions) as well as reduced inter-hemispheric rs-FC in the HIE group. In addition, HIE neonates demonstrated increased rs-FC between motor regions and frontal, temporal and parietal cortices but decreased rs-FC with the cerebellum.

DISCUSSION

These preliminary results provide initial evidence for the disruption of functional communication with the motor network in neonates with HIE. Further studies are necessary to both validate these findings in a larger dataset as well as to determine if rs-fMRI measurements collected at birth may have the potential to serve as a prognostic marker in addition to the traditional combination of clinical measurements and conventional MRI.

Protocol for the Birth Asphyxia in African Newborns (Baby BRAiN) Study: a Neonatal Encephalopathy Feasibility Cohort Study

BACKGROUND: Neonatal encephalopathy (NE) is a leading cause of child mortality worldwide and contributes substantially to stillbirths and long-term disability. Ninety-nine percent of deaths from NE occur in low-and-middle-income countries (LMICs). Whilst therapeutic hypothermia significantly improves outcomes in high-income countries, its safety and effectiveness in diverse LMIC contexts remains debated. Important differences in the aetiology, nature and timing of neonatal brain injury likely influence the effectiveness of postnatal interventions, including therapeutic hypothermia. METHODS: This is a prospective pilot feasibility cohort study of neonates with NE conducted at Kawempe National Referral Hospital, Kampala, Uganda. Neurological investigations include continuous video electroencephalography (EEG) (days 1-4), serial cranial ultrasound imaging, and neonatal brain Magnetic Resonance Imaging and Spectroscopy (MRI/ MRS) (day 10-14). Neurodevelopmental follow-up will be continued to 18-24 months of age including Prechtl's Assessment of General Movements, Bayley Scales of Infant Development, and a formal scored neurological examination. The primary outcome will be death and moderate-severe neurodevelopmental impairment at 18-24 months. Findings will be used to inform explorative science and larger trials, aiming to develop urgently needed neuroprotective and neurorestorative interventions for NE applicable for use in diverse settings. DISCUSSION: The primary aims of the study are to assess the feasibility of establishing a facility-based cohort of children with NE in Uganda, to enhance our understanding of NE in a low-resource sub-Saharan African setting and provide infrastructure to conduct high-quality research on neuroprotective/ neurorestorative strategies to reduce death and disability from NE. Specific objectives are to establish a NE cohort, in order to 1) investigate the clinical course, aetiology, nature and timing of perinatal brain injury; 2) describe electrographic activity and quantify seizure burden and the relationship with adverse outcomes, and; 3) develop capacity for neonatal brain MRI/S and examine associations with early neurodevelopmental outcomes.

Challenges in developing therapeutic strategies for mild neonatal encephalopathy

There is increasing evidence that infants with mild neonatal encephalopathy (NE) have significant risks of mortality, brain injury and adverse neurodevelopmental outcomes. In the era of therapeutic hypothermia, infants need to be diagnosed within 6 hours of birth, corresponding with the window of opportunity for treatment of moderate to severe NE, compared to the retrospective grading over 2 to 3 days, typically with imaging and formal electroencephalographic assessment in the pre-hypothermia era. This shift in diagnosis may have increased the apparent prevalence of brain damage and poor neurological outcomes seen in infants with mild NE in the era of hypothermia. Abnormal short term outcomes observed in infants with mild NE include seizures, abnormal neurologic examination at discharge, abnormal brain magnetic resonance imaging and difficulty feeding. At 2 to 3 years of age, mild NE has been associated with an increased risk of autism, language and cognitive deficits. There are no approved treatment strategies for these infants as they were not included in the initial randomized controlled trials for therapeutic hypothermia. However, there is already therapeutic creep, with many centers treating infants with mild NE despite the limited evidence for its safety and efficacy. The optimal duration of treatment and therapeutic window of opportunity for effective treatment need to be specifically established for mild NE as the evolution of injury is likely to be slower, based on preclinical data. Randomized controlled trials of therapeutic hypothermia for infants with mild NE are urgently required to establish the safety and efficacy of treatment. This review will examine the evidence for adverse outcomes after mild NE and dissect some of the challenges in developing therapeutic strategies for mild NE, before analyzing the evidence for therapeutic hypothermia and other strategies for treatment of these infants.

Predictive performance and metabolite dynamics of proton MR spectroscopy in neonatal hypoxic-ischemic encephalopathy

BACKGROUND

Prognostic value of proton MR spectroscopy (H-MRS) in hypoxic-ischemic encephalopathy (HIE) is acknowledged; however, effects of gestational age (GA) and postnatal age (PA) on prediction and metabolite levels are unknown.

METHODS

One hundred and sixty-nine newborns with moderate-to-severe HIE were studied, having ≥1 H-MRS scan during postnatal days 0-14 and known neurodevelopmental outcome (Bayley-II score/cerebral palsy/death). Initial scans were categorized by PA (day 1-3/4-6/≥7), and metabolite ratios were compared by predictive value. Metabolite dynamics were assessed in a total of 214 scans performed in the study population, using regression modeling, with predictors GA, PA, and outcome.

RESULTS

N-acetyl-aspartate (NAA)/creatine (Cr) and myo-inositol (mI)/NAA height ratios were consistently associated with outcome throughout the first 14 days, with the highest predictive value in the late (≥7 days) period (AUC = 0.963 and 0.816, respectively). Neither GA nor PA had an overall effect on these metabolite ratios, which showed strongest association with outcome (p < 0.001). Assessed separately in patients with good outcome, GA became a significant covariate for metabolite ratios (p = 0.0058 and 0.0002, respectively). However, this association disappeared in the poor outcome group.

CONCLUSIONS

In HIE, NAA/Cr and mI/NAA give most accurate outcome prediction throughout postnatal days 0-14. GA only affected metabolite levels in the good outcome group.

IMPACT

Proton MR spectroscopy metabolite ratios N-acetyl-aspartate/creatine and myo-inositol/N-acetyl-aspartate have persistently high predictive value throughout postnatal days 0-14 in newborns with hypoxic-ischemic encephalopathy, with the highest predictive power between postnatal days 7 and 14. Overall, neither metabolite ratio was affected by gestational age nor by postnatal age, while they showed the strongest association with neurological outcome. However, in newborns facing good outcome, metabolite ratios were associated with gestational age, whereas in cases facing poor outcome, this association disappeared. Proton MR spectroscopy provides valuable prognostic information in neonatal hypoxic-ischemic encephalopathy throughout the first 2 weeks of life, irrespective of the timing of MR scan.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association Between Increased Seizures During Rewarming After Hypothermia for Neonatal Hypoxic Ischemic Encephalopathy and Abnormal Neurodevelopmental Outcomes at 2-Year Follow-up: A Nested Multisite Cohort Study

Importance

Compared with normothermia, hypothermia has been shown to reduce death or disability in neonatal hypoxic ischemic encephalopathy but data on seizures during rewarming and associated outcomes are scarce.

Objective

To determine whether electrographic seizures are more likely to occur during rewarming compared with the preceding period and whether they are associated with abnormal outcomes in asphyxiated neonates receiving hypothermia therapy.

Design, Setting, and Participants

This prespecified nested cohort study of infants enrolled in the Optimizing Cooling (OC) multicenter Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network trial from December 2011 to December 2013 with 2 years' follow-up randomized infants to either 72 hours of cooling (group A) or 120 hours (group B). The main trial included 364 infants. Of these, 194 were screened, 10 declined consent, and 120 met all predefined inclusion criteria. A total of 112 (90%) had complete data for death or disability. Data were analyzed from January 2018 to January 2020.

Interventions

Serial amplitude electroencephalography recordings were compared in the 12 hours prior and 12 hours during rewarming for evidence of electrographic seizure activity by 2 central amplitude-integrated electroencephalography readers blinded to treatment arm and rewarming epoch. Odds ratios and 95% CIs were evaluated following adjustment for center, prior seizures, depth of cooling, and encephalopathy severity.

Main Outcomes and Measures

The primary outcome was the occurrence of electrographic seizures during rewarming initiated at 72 or 120 hours compared with the preceding 12-hour epoch. Secondary outcomes included death or moderate or severe disability at age 18 to 22 months. The hypothesis was that seizures during rewarming were associated with higher odds of abnormal neurodevelopmental outcomes.

Results

A total of 120 newborns (70 male [58%]) were enrolled (66 in group A and 54 in group B). The mean (SD) gestational age was 39 (1) weeks. There was excellent interrater agreement (κ, 0.99) in detection of seizures. More infants had electrographic seizures during the rewarming epoch compared with the preceding epoch (group A, 27% vs 14%; P = .001; group B, 21% vs 10%; P = .03). Adjusted odd ratios (95% CIs) for seizure frequency during rewarming were 2.7 (1.0-7.5) for group A and 3.2 (0.9-11.6) for group B. The composite death or moderate to severe disability outcome at 2 years was significantly higher in infants with electrographic seizures during rewarming (relative risk [95% CI], 1.7 [1.25-2.37]) after adjusting for baseline clinical encephalopathy and seizures as well as center.

Conclusions and Relevance

Findings that higher odds of electrographic seizures during rewarming are associated with death or disability at 2 years highlight the necessity of electroencephalography monitoring during rewarming in infants at risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT01192776.

Lipid Profiles from Dried Blood Spots Reveal Lipidomic Signatures of Newborns Undergoing Mild Therapeutic Hypothermia after Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is associated with perinatal brain injury, which may lead to disability or death. As the brain is a lipid-rich organ, various lipid species can be significantly impacted by HIE and these correlate with specific changes to the lipidomic profile in the circulation. Objective: To investigate the peripheral blood lipidomic signature in dried blood spots (DBS) from newborns with HIE. Using univariate analysis, multivariate analysis and sPLS-DA modelling, we show that newborns with moderate-severe HIE (n = 46) who underwent therapeutic hypothermia (TH) displayed a robust peripheral blood lipidomic signature comprising 29 lipid species in four lipid classes; namely phosphatidylcholine (PC), lysophosphatidylcholine (LPC), triglyceride (TG) and sphingomyelin (SM) when compared with newborns with mild HIE (n = 18). In sPLS-DA modelling, the three most discriminant lipid species were TG 50:3, TG 54:5, and PC 36:5. We report a reduction in plasma TG and SM and an increase in plasma PC and LPC species during the course of TH in newborns with moderate-severe HIE, compared to a single specimen from newborns with mild HIE. These findings may guide the research in nutrition-based intervention strategies after HIE in synergy with TH to enhance neuroprotection.

Outcome of Infants with Hypoxic-Ischemic Encephalopathy Treated by Whole Body Cooling and Magnesium Sulfate

Therapeutic hypothermia (TH) either by selective head cooling or whole-body cooling decreases brain damage and provide neuroprotection and reduced mortality rate in cases of moderate-to-severe hypoxia-ischemia encephalopathy (HIE) of newborns, especially if started at first 6 hours after birth. Also, management with adjuvant therapies like magnesium sulfate (MS) provides more neuroprotection. The interventional randomized controlled research aimed to assess short-term actions of TH as sole therapy and in combination with MS as a neuroprotective agent for the treatment of HIE newborn infants. A total of 36 full-terms and near-term infants delivered at Assiut University Children's Hospital and fulfilled HIE criteria were enrolled. They were divided equally into three groups; Group 1 (n = 12) received whole body cooling during first 6 hours of life as a sole therapy; Group 2 (n = 12) received whole body cooling in addition to MS as adjuvant therapy; Group 3 (n = 12) received supportive intensive care measures as a control. TH plus MS group (group 2) had a significantly good short-term outcomes as short period of respiratory support and mechanical ventilation (p-value =0.001), less in incidence of convulsion (p-value = 0.001) and early in feeding initiation (p-value = 0.009), compared with other groups managed by TH (group 1) or by supportive treatment (group 3). In conclusion, whole body cooling in addition to MS as adjunctive therapy for the treatment of HIE neonates is safe therapy that improves short-term outcome both clinically and radiologically.

Treatment device for neonatal birth asphyxia related Hypoxic Ischemic Encephalopathy

Background

Birth asphyxia is a leading cause of neonatal brain injury, morbidity, and mortality globally. It leads to a multi-organ dysfunction in the neonate and to a neurological dysfunction called Hypoxic Ischemic Encephalopathy (HIE). Cooling therapy is commonly used to slow or stop the damaging effects of birth asphyxia. However, most of the cooling devices used in the healthcare facility do not have a rewarming functionality after cooling therapy. A separate rewarming device, usually a radiant warmer or incubator is used to rewarm the infant after therapy, causing additional burden to the healthcare system and infant families. The objective of this project was, therefore, to design and develop a cost-effective and efficient total body cooling and rewarming device.

Methods

Our design includes two water reservoirs that operate by pumping cold and warm sterile water to a mattress. After decreasing the infant’s core body temperature to 33.5 °C, the system is designed to maintain it for 72 h. Feedback for temperature regulation is provided by the rectal and mattress temperature sensors. Once the cooling therapy is completed, the system again rewarms the water inside the mattress and gradually increases the neonate temperature to 36.5–37 °C. The water temperature sensors’ effectiveness was evaluated by adding 1000 ml of water to the reservoir and cooling and warming to the required level of temperature using Peltier. Then a digital thermometer was used as a gold standard to compare with the sensor’s readings. This was performed for five iterations.

Results

The prototype was built and gone through different tests and iterations. The proposed device was tested for accuracy, cost-effectiveness and easy to use. Ninety-three point two percent accuracy has been achieved for temperature sensor measurement, and the prototype was built only with a component cost of less than 200 USD. This is excluding design, manufacturing, and other costs.

Conclusion

A device that can monitor and regulate the neonate core body temperature at the neuroprotective range is designed and developed. This is achieved by continuous monitoring and regulation of the water reservoirs, mattress, and rectal temperatures. The device also allows continuous monitoring of the infant’s body temperature, mattress temperature, reservoir temperature, and pulse rate. The proposed device has the potential to play a significant role in reducing neonatal brain injury and death due to HIE, especially in low resource settings, where the expertise and the means are scarce.

Neuronal let-7b-5p acts through the Hippo-YAP pathway in neonatal encephalopathy

Despite increasing knowledge on microRNAs, their role in the pathogenesis of neonatal encephalopathy remains to be elucidated. Herein, we identify let-7b-5p as a significant microRNA in neonates with moderate to severe encephalopathy from dried blood spots using next generation sequencing. Validation studies using Reverse Transcription and quantitative Polymerase Chain Reaction on 45 neonates showed that let-7b-5p expression was increased on day 1 in neonates with moderate to severe encephalopathy with unfavourable outcome when compared to those with mild encephalopathy. Mechanistic studies performed on glucose deprived cell cultures and the cerebral cortex of two animal models of perinatal brain injury, namely hypoxic-ischaemic and intrauterine inflammation models confirm that let-7b-5p is associated with the apoptotic Hippo pathway. Significant reduction in neuronal let-7b-5p expression corresponded with activated Hippo pathway, with increased neuronal/nuclear ratio of Yes Associated Protein (YAP) and increased neuronal cleaved caspase-3 expression in both animal models. Similar results were noted for let-7b-5p and YAP expression in glucose-deprived cell cultures. Reduced nuclear YAP with decreased intracellular let-7b-5p correlated with neuronal apoptosis in conditions of metabolic stress. This finding of the Hippo-YAP association with let-7b needs validation in larger cohorts to further our knowledge on let-7b-5p as a biomarker for neonatal encephalopathy.

Using next generation sequencing of dried blood spots and subsequent validation, Ponnusamy et al identify let-7b-5p as an elevated microRNA in neonates with moderate to severe encephalopathy. Using cell culture and murine models of perinatal brain injury they demonstrate that the effects of let-7b-5p are elicited via the Hippo-YAP pathway, which should be validated in large neonate cohorts to expand our understanding of let-7b-5p as a biomarker for neonatal encephalopathy.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of outborn versus inborn birth status on the in-hospital outcomes of neonates treated with therapeutic hypothermia: A propensity score-weighted cohort study

OBJECTIVE

To compare the risk of in-hospital mortality and morbidity between outborn and inborn neonates treated with whole body hypothermia.

METHODS

The association of outborn birth status with in-hospital mortality and morbidity, prior to NICU discharge or transfer, was assessed in a large historical cohort of neonates who had therapeutic hypothermia initiated on the day of birth. The cohort was restricted to neonates born at ≥35 weeks gestational age from 2007 to 2018. Since the sample was non-random, inverse probability weighting (IPW) derived from propensity scores was used to reduce imbalance in baseline maternal and neonatal characteristics between outborn and inborn neonates. Cox proportional hazards regression was used to assess the association between outborn status and in-hospital mortality.

RESULTS

There were 4447 neonates included in the study (2463 outborn). Outborn status was not significantly associated with an increased risk of in-hospital mortality in the unadjusted cohort (HR = 1.17, 95% CI 0.97-1.42, p = 0.10) or IPW cohort (HR = 1.09, 95% CI 0.95-1.26, p = 0.22). However, in the IPW cohort, outborn neonates were significantly more likely to have seizures (28% vs 24%, p = 0.006), anticonvulsant exposure (46% vs 41%, p = 0.002), and gastrostomy tube placement (5.8% vs 3.8%, p = 0.009) during their newborn hospitalization.

CONCLUSION

Outborn status was not significantly associated with increased in-hospital mortality among neonates treated with whole body hypothermia. However, outborn neonates were more likely to have seizures, receive anticonvulsant treatment, and undergo gastrostomy tube placement. Further study is needed to better understand the etiologies of these outcome disparities and potential implications for long-term neurodevelopmental outcomes.

Long-Term Outcome after Asphyxia and Therapeutic Hypothermia in Late Preterm Infants: A Pilot Study

Therapeutic hypothermia (THT) is the recommended treatment for neuroprotection in (near) term newborns that experience perinatal asphyxia with hypoxic-ischemic encephalopathy. The benefit of THT in preterm newborns is unknown. This pilot study aims to investigate long-term outcomes of late preterm asphyctic infants with and without THT compared to term infants. The single-center, retrospective analysis examined medical charts of infants with perinatal asphyxia born between 2008 and 2015. Long-term outcome was assessed using the Bayley Scales of Infant Development 2 at the age of (corrected) 24 months. Term (n = 31) and preterm (n = 8) infants with THT showed no differences regarding their long-term outcomes of psychomotor development (Psychomotor Developmental Index 101 ± 16 vs. 105 ± 11, p = 0.570), whereas preterm infants had a better mental outcome (Mental Developmental Index 105 ± 13 vs. 93 ± 18, p = 0.048). Preterm infants with and without (n = 69) THT showed a similar mental and psychomotor development (Mental Developmental Index 105 ± 13 vs. 96 ± 20, p = 0.527; Psychomotor Developmental Index 105 ± 11 vs. 105 ± 15, p = 0.927). The study highlights the importance of studying THT in asphyctic preterm infants. However, this study shows limitations and should not be used as a basis for decision-making in the clinical context. Results of a multicenter trial of THT for preterm infants (ID No.: CN-01540535) have to be awaited.

Neurodevelopmental outcome in neonates with hypoxic-ischaemic encephalopathy managed with therapeutic hypothermia in a tertiary-level public hospital outside an intensive care unit setting

BACKGROUND

Management of hypoxic-ischaemic encephalopathy (HIE) by therapeutic hypothermia (TH) is a major challenge in low- and middle-income countries (LMIC) because of the limited resources. Clinicians in LMIC offer this intervention outside neonatal intensive care units (NICU). The effect of this practice on neurodevelopmental outcome is not well known.

AIM

To determine neurodevelopmental outcome in neonates with HIE managed with TH outside NICU settings.

METHODS

: This was a retrospective descriptive study of neonates with HIE managed with TH and followed up for neurodevelopmental assessment at 12 and 18-24 months postnatal age. Patients were reviewed over a 24-month period. Outcome at 12 and 18-24 months was compared.

RESULTS

Of 178 neonates with HIE attending the clinic, there was information on TH for 155 (87.1%), 113 of whom (72.9%) received TH. HIE was moderate in 88% and severe in 10%. Twenty-seven (23.9%) and 16 (14.1%) were assessed at one time-point at 12 or 18-24 months, respectively, 40 (35.3%) at both time-points, and 30 (26.6%) were not assessed. At 18-24 months, 32% had moderate-to-severe disability compared with 6% at 12 months, with the sensitivity and specificity of assessment at 12 months being 50% and 100%, respectively. The disability attrition rate at 18-24 months was 50%.

CONCLUSIONS

The relatively low prevalence of disability (32%) at 18-24 months suggests that use of TH in a Level 2 nursery is feasible and possibly beneficial. More studies are needed to confirm these findings.

ABBREVIATIONS

aEEG: amplitude electroencephalogram; CP: cerebral palsy; GMDS: Griffiths mental developmental scales; GQ: general quotient; HIC: high-income countries; HIE: hypoxic-ischaemic encephalopathy; LMIC: low- and middle-income countries; LTFU: loss to follow-up; NICU: neonatal intensive care unit; TH: therapeutic hypothermia; TOBY: total body hypothermia.

Hypotension in Preterm Infants (HIP) randomised trial

OBJECTIVE

To determine whether restricting the use of inotrope after diagnosis of low blood pressure (BP) in the first 72 hours of life affects survival without significant brain injury at 36 weeks of postmenstrual age (PMA) in infants born before 28 weeks of gestation.

DESIGN

Double-blind, placebo-controlled randomised trial. Caregivers were masked to group assignment.

SETTING

10 sites across Europe and Canada.

PARTICIPANTS

Infants born before 28 weeks of gestation were eligible if they had an invasive mean BP less than their gestational age that persisted for ≥15 min in the first 72 hours of life and a cerebral ultrasound free of significant (≥ grade 3) intraventricular haemorrhage.

INTERVENTION

Participants were randomly assigned to saline bolus followed by either a dopamine infusion (standard management) or placebo (5% dextrose) infusion (restrictive management).

PRIMARY OUTCOME

Survival to 36 weeks of PMA without severe brain injury.

RESULTS

The trial terminated early due to significant enrolment issues (7.7% of planned recruitment). 58 infants were enrolled between February 2015 and September 2017. The two groups were well matched for baseline variables. In the standard group, 18/29 (62%) achieved the primary outcome compared with 20/29 (69%) in the restrictive group (p=0.58). Additional treatments for low BP were used less frequently in the standard arm (11/29 (38%) vs 19/29 (66%), p=0.038).

CONCLUSION

Though this study lacked power, we did not detect major differences in clinical outcomes between standard or restrictive approach to treatment. These results will inform future studies in this area.

TRIAL REGISTRATION NUMBER

NCT01482559, EudraCT 2010-023988-17.

Glomerular Filtration Rate in Asphyxiated Neonates Under Therapeutic Whole-Body Hypothermia, Quantified by Mannitol Clearance

BACKGROUND

Therapeutic hypothermia (TH) is an established intervention to improve the outcome of neonates with moderate-to-severe hypoxic-ischemic encephalopathy resulting from perinatal asphyxia. Despite this beneficial effect, TH may further affect drug elimination pathways such as the glomerular filtration rate.

OBJECTIVES

The objective of this study was to quantify the effect of TH in addition to asphyxia on mannitol clearance as a surrogate for the glomerular filtration rate.

METHODS

The effect of asphyxia and TH (mild vs moderate/severe) on mannitol clearance was assessed using a population approach, based on mannitol observations collected in the ALBINO (ALlopurinol in addition to TH for hypoxic-ischemic Brain Injury on Neurocognitive Outcome) trial, as some were exposed to a second dose of 10 mg/kg intravenous mannitol as placebo to ensure blinding. Pharmacokinetic analysis and model development were conducted using NONMEM version 7.4.

RESULTS

Based on 77 observations from 17 neonates (TH = 13), a one-compartment model with first-order linear elimination best described the observed data. To account for prenatal glomerular filtration rate maturation, both birthweight and gestational age were implemented as clearance covariates using an earlier published three-quarters power function and a sigmoid hyperbolic function. Our final model predicted a mannitol clearance of 0.15 L/h for a typical asphyxia neonate (39.5 weeks, birthweight 3.25 kg, no TH), lower than the reported value of 0.33 L/h for a healthy neonate of similar age and weight. By introducing TH as a binary covariate on clearance, the additional impact of TH on mannitol clearance was quantified (60% decrease).

CONCLUSIONS

Mannitol clearance was decreased by approximately 60% in neonates undergoing TH, although this is likely confounded with asphyxia severity.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03162653.

Prognostic value of neonatal EEG following therapeutic hypothermia in survivors of hypoxic-ischemic encephalopathy

OBJECTIVE

Early prediction of neurological deficits following neonatal hypoxic-ischemic encephalopathy (HIE) may help to target support. Neonatal animal models suggest that recovery following hypoxia-ischemia depends upon cortical bursting. To test whether this holds in human neonates, we correlated the magnitude of cortical bursting during recovery (≥postnatal day 3) with neurodevelopmental outcomes.

METHODS

We identified 41 surviving infants who received therapeutic hypothermia for HIE (classification at hospital discharge: 19 mild, 18 moderate, 4 severe) and had 9-channel electroencephalography (EEG) recordings as part of their routine care. We correlated burst power with Bayley-III cognitive, motor and language scores at median 24 months. To examine whether EEG offered additional prognostic information, we controlled for structural MRI findings.

RESULTS

Higher power of central and occipital cortical bursts predicted worse cognitive and language outcomes, and higher power of central cortical bursts predicted worse motor outcome, all independently of structural MRI findings.

CONCLUSIONS

Clinical EEG after postnatal day 3 may provide additional prognostic information by indexing persistent active mechanisms that either support recovery or exacerbate brain damage, especially in infants with less severe encephalopathy.

SIGNIFICANCE

These findings could allow for the effect of clinical interventions in the neonatal period to be studied instantaneously in the future.

Neonatal hypoxic-ischemic encephalopathy diagnosis and treatment: a National Survey in China

Background

Neonatal hypoxic-ischemic encephalopathy (HIE) affects as many as 100,000 infants each year in China. Therapeutic hypothermia reduces HIE related mortality and long-term neurodevelopmental disabilities. National guidelines for HIE management were published a decade ago. This study aimed to investigate the current status of HIE diagnosis and treatment in China.

Method

This prospective cross-sectional national survey used a questionnaire evaluating practices related to HIE management. Descriptive statistics and Chi-square or Fisher’s exact test were used, and a p-value of < 0.05 was considered significant.

Results

The 273 hospitals that completed the survey were located in 31 of the 34 provincial districts in China. Eighty-eight percent of the hospitals were Level III hospitals, and 74% treated 10 or more HIE cases annually. Awareness rates of the national guidelines for HIE diagnosis, HIE treatment, and therapeutic hypothermia protocol were 85, 63, and 78%, respectively. Neurological manifestations and blood gas were used as HIE diagnostic criteria by 96% (263/273) and 68% (186/273) of the hospitals, respectively. Therapeutic hypothermia was used in 54% (147/273) of hospitals. The percentage of general hospitals that implemented therapeutic hypothermia (43%, 71/165) was significantly lower than that in maternity and infant hospitals (67%, 49/73) (χ² = 11.752, p = 0.001) and children’s hospitals (77%, 27/35) (χ² = 13.446, p < 0.001). Reasons for not providing therapeutic hypothermia included reduction of HIE cases in recent years (39%), high cost of cooling devices and treatment (31%), lack of training (26%), and safety concerns (4%). Among the hospitals that provided therapeutic hypothermia, 27% (39/147) were in full compliance with the recommended protocol. Eighty-one percent (222/273) of the hospitals treated HIE infants with putative neuroprotective agents alone or in combination with cooling. Ninety-one percent of the hospitals had long-term neurodevelopmental follow-up programs for infants with HIE.

Conclusions

There is significant heterogeneity in HIE diagnosis and treatment in China. Therapeutic hypothermia has not become a standard of care for neonatal HIE nationwide. Unproven agents are widely used for HIE treatment. Nationwide standardization of HIE management and dissemination of therapeutic hypothermia represent the opportunities to reduce mortality and improve long-term neurodevelopmental outcomes of children affected by HIE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02737-6.

Creatinine Trends and Patterns in Neonates Undergoing Whole Body Hypothermia: A Systematic Review

Many neonates undergoing whole body hypothermia (WBH) following moderate to severe perinatal asphyxia may also suffer from renal impairment. While recent data suggest WBH-related reno-protection, differences in serum creatinine (Scr) patterns to reference patterns were not yet reported. We therefore aimed to document Scr trends and patterns in asphyxiated neonates undergoing WBH and compared these to centiles from a reference Scr data set of non-asphyxiated (near)term neonates. Using a systematic review strategy, reports on Scr trends (mean ± SD, median or interquartile range) were collected (day 1-7) in WBH cohorts and compared to centiles of an earlier reported reference cohort of non-asphyxia cases. Based on 13 papers on asphyxia + WBH cases, a pattern of postnatal Scr trends in asphyxia + WBH cases was constructed. Compared to the reference 50th centile Scr values, mean or median Scr values at birth and up to 48 h were higher in asphyxia + WBH cases with a subsequent uncertain declining trend towards, at best, high or high-normal creatinine values afterwards. Such patterns are valuable for anticipating average changes in renal drug clearance but do not yet cover the relevant inter-patient variability observed in WBH cases, as this needs pooling of individual Screa profiles, preferably beyond the first week of life.

Morphine and fentanyl exposure during therapeutic hypothermia does not impair neurodevelopment

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

Altered inflammasome activation in neonatal encephalopathy persists in childhood

Neonatal encephalopathy (NE) is characterized by altered neurological function in term infants and inflammation plays an important pathophysiological role. Inflammatory cytokines interleukin (IL)‐1β, IL‐1ra and IL‐18 are activated by the nucleotide‐binding and oligomerization domain (NOD)‐, leucine‐rich repeat domain (LRR)‐ and NOD‐like receptor protein 3 (NLRP3) inflammasome; furthermore, we aimed to examine the role of the inflammasome multiprotein complex involved in proinflammatory responses from the newborn period to childhood in NE. Cytokine concentrations were measured by multiplex enzyme‐linked immunosorbent assay (ELISA) in neonates and children with NE in the absence or presence of lipopolysaccharide (LPS) endotoxin. We then investigated expression of the NLRP3 inflammasome genes, NLRP3, IL‐1β and ASC by polymerase chain reaction (PCR). Serum samples from 40 NE patients at days 1 and 3 of the first week of life and in 37 patients at age 4–7 years were analysed. An increase in serum IL‐1ra and IL‐18 in neonates with NE on days 1 and 3 was observed compared to neonatal controls. IL‐1ra in NE was decreased to normal levels at school age, whereas serum IL‐18 in NE was even higher at school age compared to school age controls and NE in the first week of life. Percentage of LPS response was higher in newborns compared to school‐age NE. NLRP3 and IL‐1β gene expression were up‐regulated in the presence of LPS in NE neonates and NLRP3 gene expression remained up‐regulated at school age in NE patients compared to controls. Increased inflammasome activation in the first day of life in NE persists in childhood, and may increase the window for therapeutic intervention.

The Kynurenic Acid Analog SZR72 Enhances Neuronal Activity after Asphyxia but Is Not Neuroprotective in a Translational Model of Neonatal Hypoxic Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) remains to be a major cause of long-term neurodevelopmental deficits in term neonates. Hypothermia offers partial neuroprotection warranting research for additional therapies. Kynurenic acid (KYNA), an endogenous product of tryptophan metabolism, was previously shown to be beneficial in rat HIE models. We sought to determine if the KYNA analog SZR72 would afford neuroprotection in piglets. After severe asphyxia (pHa = 6.83 ± 0.02, ΔBE = -17.6 ± 1.2 mmol/L, mean ± SEM), anesthetized piglets were assigned to vehicle-treated (VEH), SZR72-treated (SZR72), or hypothermia-treated (HT) groups (n = 6, 6, 6; Tcore = 38.5, 38.5, 33.5 °C, respectively). Compared to VEH, serum KYNA levels were elevated, recovery of EEG was faster, and EEG power spectral density values were higher at 24 h in the SZR72 group. However, instantaneous entropy indicating EEG signal complexity, depression of the visual evoked potential (VEP), and the significant neuronal damage observed in the neocortex, the putamen, and the CA1 hippocampal field were similar in these groups. In the caudate nucleus and the CA3 hippocampal field, neuronal damage was even more severe in the SZR72 group. The HT group showed the best preservation of EEG complexity, VEP, and neuronal integrity in all examined brain regions. In summary, SZR72 appears to enhance neuronal activity after asphyxia but does not ameliorate early neuronal damage in this HIE model.

Hydrogen-induced Neuroprotection in Neonatal Hypoxic-ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) remains to be a major cause of morbidity, mortality and severe neurodevelopmental disability in term neonates. Moderate whole body hypothermia is an established, effective neuroprotective therapy to reduce mortality and long-term disability associated with HIE, however, research for adjunct therapies is still warranted to complement the effect of hypothermia. In the last decade, molecular hydrogen emerged as a simple, available, inexpensive substance with advantageous pharmacokinetics to ameliorate hypoxic-ischemic cellular damage. The present review examines the preclinical studies employing hydrogen to combat the deleterious consequences of hypoxic-ischemic insults in rodent and piglet HIE models. Hydrogen exerted unequivocal neuroprotective actions shown by preserved neurovascular function, neuronal viability, and neurocognitive functions in virtually all model species and hypoxic-ischemic insult types tested. Administration of hydrogen started in most studies after the hypoxic-ischemic insult enhancing the translational value of the findings. Among the explored mechanisms of hydrogen-induced neuroprotection, antioxidant, anti- apoptotic and anti-inflammatory effects appeared to be dominant. Unfortunately, the additive neuroprotective effect of hydrogen and therapeutic hypothermia has not yet been demonstrated, thus such studies are warranted to promote the clinical testing of molecular hydrogen as an adjunct neuroprotective treatment of HIE.

Hypothermic Shock Applied After Perinatal Asphyxia Prevents Retinal Damage in Rats

Perinatal asphyxia (PA) can cause retinopathy and different degrees of visual loss, including total blindness. In a rat model of PA, we have previously shown a protective effect of hypothermia on the retina when applied simultaneously with the hypoxic insult. In the present work, we evaluated the possible protective effect of hypothermia on the retina of PA rats when applied immediately after delivery. Four experimental groups were studied: Rats born naturally as controls (CTL), animals that were exposed to PA for 20 min at 37°C (PA), animals exposed to PA for 20 min at 15°C (HYP), and animals that were exposed to PA for 20 min at 37°C and, immediately after birth, kept for 15 min at 8°C (HYP-PA). To evaluate the integrity of the visual pathway, animals were subjected to electroretinography at 45 days of age. Molecular (real time PCR) and histological (immunohistochemistry, immunofluorescence, TUNEL assay) techniques were applied to the eyes of all experimental groups collected at 6, 12, 24, and 48 h, and 6 days after birth. PA resulted in a significant reduction in the amplitude of the a- and b-wave and oscillatory potentials (OP) of the electroretinogram. All animals treated with hypothermia had a significant correction of the a-wave and OP, but the b-wave was fully corrected in the HYP group but only partially in the HYP-PA group. The number of TUNEL-positive cells increased sharply in the ganglion cell layer of the PA animals and this increase was significantly prevented by both hypothermia treatments. Expression of the cold-shock proteins, cold-inducible RNA binding protein (CIRP) and RNA binding motif protein 3 (RBM3), was undetectable in retinas of the CTL and PA groups, but they were highly expressed in ganglion neurons and cells of the inner nuclear layer of the HYP and HYP-PA groups. In conclusion, our results suggest that a post-partum hypothermic shock could represent a useful and affordable method to prevent asphyxia-related vision disabling sequelae.

Quality improvement for reducing utilization drift in hypoxic-ischemic encephalopathy management

OBJECTIVES

Therapeutic hypothermia is an effective neuroprotective intervention for infants with moderate or severe hypoxic-ischemic encephalopathy (HIE). With the introduction of new medical therapy comes a learning curve with regards to its proper implementation and understanding of eligibility guidelines. We hypothesized that variation in patient selection and lack of adherence to established protocols contributed to the utilization drift away from the original eligibility guidelines.

METHODS

A retrospective cohort study was conducted including infants who received therapeutic hypothermia in the neonatal intensive care unit (NICU) for HIE to determine utilization drift. We then used QI methodology to address gaps in medical documentation that may lead to the conclusion that therapeutic hypothermia was inappropriately applied.

RESULTS

We identified 54% of infants who received therapeutic hypothermia who did not meet the clinical, physiologic, and neurologic examination criteria for this intervention based on provider admission and discharge documentation within the electronic medical record (EMR). Review of the charts identified incomplete documentation in 71% of cases and led to the following interventions: 1) implementation of EMR smartphrases; 2) engagement of key stakeholders and education of faculty, residents, and neonatal nurse practitioners; and 3) performance measurement and sharing of data. We were able to improve both adherence to the therapeutic hypothermia guidelines and achieve 100% documentation of the modified Sarnat score.

CONCLUSIONS

Incomplete documentation can lead to the assumption that therapeutic hypothermia was inappropriately applied when reviewing a patient's EMR. However, in actual clinical practice physicians follow the clinical guidelines but are not documenting their medical decision making completely. QI methodology addresses this gap in documentation, which will help determine the true utilization drift of therapeutic hypothermia in future studies.