Effect of therapeutic hypothermia on DNA damage and neurodevelopmental outcome among term neonates with perinatal asphyxia: a randomized controlled trial

Post-Asphyxial Aftercare and Management of Neonates in Low- and Middle-Income Countries: A Systematic Evidence Synthesis

INTRODUCTION

Effective post-resuscitation care is crucial for improving outcomes in neonates post-asphyxia. This review aimed to provide a comprehensive overview of post-asphyxial aftercare strategies and forms part of a supplement describing an extensive synthesis of effective newborn interventions in low- and middle-income countries (LMICs).

METHODS

Evidence was generated by performing de novo reviews, updates to reviews via systematic searches, and reanalyses of studies conducted in LMICs from existing reviews.

RESULTS

Sixty-one trials recruiting 5,046 term infants post-asphyxia were included across all intervention domains. Limited studies were available from LMICs related to fluid restriction, antiseizure medications, and early interventions to improve developmental outcomes. Our reanalysis of whole-body cooling trials in LMICs found effects on neonatal mortality and mortality or neurological disability in infancy differed significantly based on the care center and type of cooling device used. Pharmacological therapies for neuroprotection evaluated in 27 trials in middle-income countries had varied effects in neonates with encephalopathy. Majority of the trials (60%) focused on magnesium sulfate therapy and showed significant improvements in short-term mortality and morbidities.

CONCLUSION

The sample sizes of included trials were relatively small, and the certainty of evidence ranged from very low to moderate. Evidence on long-term survival and neurodevelopmental outcomes was limited. Further research on promising neuroprotective therapies and factors affecting their implementation in low-resource contexts is required. To reduce the high burden related to asphyxia in LMICs, this review underscores the need for a paradigm shift toward prevention, and strategies that emphasize improving antenatal and obstetric care.

2024 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

This is the eighth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recent published resuscitation evidence reviewed by the International Liaison Committee on Resuscitation task force science experts. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research.

Neonatal encephalopathy: a systematic review of reported treatment outcomes

BACKGROUND

Neonatal encephalopathy (NE) is a multi-organ condition potentially leading to death or long-term neurodisability. Therapeutic hypothermia is the standard treatment for NE; however, long-term impairments remain common. Studies of new treatments for NE often measure and report different outcomes. Core outcome sets (COSs), a minimum set of outcomes to be measured and reported in all studies for a condition, address this problem. This paper aimed to identify outcomes reported (primary, secondary, adverse events and other reported outcomes) in (1) randomised trials and (2) systematic reviews of randomised trials of interventions for the treatment of NE in the process of developing a COS for interventions for the treatment of NE.

METHODS

We completed a systematic search for outcomes used to evaluate treatments for NE using MEDLINE, Embase, Cochrane CENTRAL, the Cochrane Database of Systematic Reviews and the WHO International Clinical Trials Registry Platform. Two reviewers screened all included articles independently. Outcomes were extracted verbatim, similar outcomes were grouped and outcome domains were developed.

RESULTS

386 outcomes were reported in 116 papers, from 85 studies. Outcomes were categorised into 18 domains. No outcome was reported by all studies, a single study reported 11 outcomes and it was not explicitly stated that outcomes had input from parents.

DISCUSSION

Heterogeneity in reported outcomes means that synthesis of studies evaluating new treatments for NE remains difficult. A COS, that includes parental/family input, is needed to ensure consistency in measuring and reporting outcomes, and to enable comparison of randomised trials.

Therapeutic hypothermia for neonates with hypoxic-ischaemic encephalopathy in low- and lower-middle-income countries: a systematic review and meta-analysis

Hypoxic-ischaemic encephalopathy (HIE) is a major cause of mortality and neurodevelopmental disability, especially in low-income countries. While therapeutic hypothermia has been shown to reduce morbidity and mortality in infants with HIE, some clinical trials in low-income countries have reported an increase in the risk of mortality. We conducted a systematic review and meta-analysis of all randomized and quasi-randomized controlled trials conducted in low-income and lower-middle-income countries that compared cooling therapy with standard care for HIE. Our primary outcome was composite of neonatal mortality and neurodevelopmental disability at 6 months or beyond. The review was registered with PROSPERO (CRD42022352728). Our review included 11 randomized controlled trials with 1324 infants with HIE. The composite of death or disability at 6 months or beyond was lower in therapeutic hypothermia group (RR 0.78, 95% CI 0.66-0.92, I2 = 85%). Neonatal mortality rate did not differ significantly between cooling therapy and standard care (RR 0.92, 95% CI 0.76-1.13, I2 = 61%). Additionally, the cooled group exhibited significantly lower rates of neurodevelopmental disability at or beyond 6 months (RR 0.34, 95%CI 0.22-0.52, I2 = 0%). Our analysis found that neonatal mortality rate did not differ between cooled and noncooled infants in low- and lower-middle-income countries. Cooling may have a beneficial effect on neurodevelopmental disability and the composite of death or disability at 6 months or beyond.

Prevalence of hearing impairment in neonatal encephalopathy due to hypoxia-ischemia: a systematic review and meta-analysis

BACKGROUND

This systematic review was undertaken to estimate the overall prevalence of hearing impairment in survivors of neonatal HIE.

METHODS

PubMed, EMBASE, CINAHL, EMCARE and Cochrane databases, mednar (gray literature) were searched till January 2023. Randomized controlled trials and observational studies were included. The main outcome was estimation of overall prevalence of hearing impairment in survivors of HIE.

RESULTS

A total of 71studies (5821 infants assessed for hearing impairment) were included of which 56 were from high income countries (HIC) and 15 from low- or middle-income countries (LMIC). Overall prevalence rate of hearing impairment in cooled infants was 5% (95% CI: 3-6%, n = 4868) and 3% (95% CI: 1-6%, n = 953) in non-cooled HIE infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%).

CONCLUSIONS

These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE. There is a need for more data from LMICs and standardization of reporting hearing impairment.

IMPACT

The overall prevalence rate of hearing impairment in cooled infants with HIE was 5% (95% CI: 3-6%) and 3% (95% CI: 1-6%) in the non-cooled infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%). These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Whole-Body Hypothermia, Cerebral Magnetic Resonance Biomarkers, and Outcomes in Neonates With Moderate or Severe Hypoxic-Ischemic Encephalopathy Born at Tertiary Care Centers vs Other Facilities: A Nested Study Within a Randomized Clinical Trial

Importance

The association between place of birth and hypothermic neuroprotection after hypoxic-ischemic encephalopathy (HIE) in low- and middle-income countries (LMICs) is unknown.

Objective

To ascertain the association between place of birth and the efficacy of whole-body hypothermia for protection against brain injury measured by magnetic resonance (MR) biomarkers among neonates born at a tertiary care center (inborn) or other facilities (outborn).

Design, Setting, and Participants

This nested cohort study within a randomized clinical trial involved neonates at 7 tertiary neonatal intensive care units in India, Sri Lanka, and Bangladesh between August 15, 2015, and February 15, 2019. A total of 408 neonates born at or after 36 weeks' gestation with moderate or severe HIE were randomized to receive whole-body hypothermia (reduction of rectal temperatures to between 33.0 °C and 34.0 °C; hypothermia group) for 72 hours or no whole-body hypothermia (rectal temperatures maintained between 36.0 °C and 37.0 °C; control group) within 6 hours of birth, with follow-up until September 27, 2020.

Exposure

3T MR imaging, MR spectroscopy, and diffusion tensor imaging.

Main Outcomes and Measures

Thalamic N-acetyl aspartate (NAA) mmol/kg wet weight, thalamic lactate to NAA peak area ratios, brain injury scores, and white matter fractional anisotropy at 1 to 2 weeks and death or moderate or severe disability at 18 to 22 months.

Results

Among 408 neonates, the mean (SD) gestational age was 38.7 (1.3) weeks; 267 (65.4%) were male. A total of 123 neonates were inborn and 285 were outborn. Inborn neonates were smaller (mean [SD], 2.8 [0.5] kg vs 2.9 [0.4] kg; P = .02), more likely to have instrumental or cesarean deliveries (43.1% vs 24.7%; P = .01), and more likely to be intubated at birth (78.9% vs 29.1%; P = .001) than outborn neonates, although the rate of severe HIE was not different (23.6% vs 17.9%; P = .22). Magnetic resonance data from 267 neonates (80 inborn and 187 outborn) were analyzed. In the hypothermia vs control groups, the mean (SD) thalamic NAA levels were 8.04 (1.98) vs 8.31 (1.13) among inborn neonates (odds ratio [OR], -0.28; 95% CI, -1.62 to 1.07; P = .68) and 8.03 (1.89) vs 7.99 (1.72) among outborn neonates (OR, 0.05; 95% CI, -0.62 to 0.71; P = .89); the median (IQR) thalamic lactate to NAA peak area ratios were 0.13 (0.10-0.20) vs 0.12 (0.09-0.18) among inborn neonates (OR, 1.02; 95% CI, 0.96-1.08; P = .59) and 0.14 (0.11-0.20) vs 0.14 (0.10-0.17) among outborn neonates (OR, 1.03; 95% CI, 0.98-1.09; P = .18). There was no difference in brain injury scores or white matter fractional anisotropy between the hypothermia and control groups among inborn or outborn neonates. Whole-body hypothermia was not associated with reductions in death or disability, either among 123 inborn neonates (hypothermia vs control group: 34 neonates [58.6%] vs 34 [56.7%]; risk ratio, 1.03; 95% CI, 0.76-1.41), or 285 outborn neonates (hypothermia vs control group: 64 neonates [46.7%] vs 60 [43.2%]; risk ratio, 1.08; 95% CI, 0.83-1.41).

Conclusions and Relevance

In this nested cohort study, whole-body hypothermia was not associated with reductions in brain injury after HIE among neonates in South Asia, irrespective of place of birth. These findings do not support the use of whole-body hypothermia for HIE among neonates in LMICs.

Trial Registration

ClinicalTrials.gov Identifier: NCT02387385.

Glimpses from My Academic Journey : Based on the 15th Dr. K. C. Chaudhuri Lifetime Achievement Award Oration Delivered on 9th October 2022

This article is based on the contents of 'Dr. K. C. Chaudhuri Lifetime Achievement Award Oration' delivered on the Indian Journal of Pediatrics Annual Day 2022. The author shares glimpses of his academic journey from a remote village to a central Institute. This includes his career as a medical teacher and developing the Department of Neonatology at JIPMER, Pondicherry. This article is primarily focused on some of the significant research conducted during his tenure, like perinatal asphyxia, therapeutic hypothermia, neonatal sepsis, intrauterine growth restriction, and human milk banking.

Therapeutic Hypothermia for Perinatal Asphyxia in India-Experience and Evidence

Therapeutic hypothermia is an established therapy with proven benefit for term neonates with moderate and severe hypoxic-ischemic encephalopathy (HIE). Many centers in India have started therapeutic cooling of asphyxiated infants. There is enough evidence for the beneficial effect of cooling from the randomized trials conducted in India. However, the recently published hypothermia for encephalopathy in low- and middle-income countries (HELIX) trial has contrasting findings. In this context, this review is written summarizing the available experience and evidence for therapeutic hypothermia for perinatal asphyxia in India.

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.

Therapeutic Hypothermia for Neonatal Encephalopathy in Low- and Middle-Income Countries: A Literature Review

AIMS

This structured review aimed to discuss the existing literature on therapeutic hypothermia for moderate to severe neonatal encephalopathy exclusively in low- and middle-income countries (LMICs).

METHODS

Medline, Embase, CINHAL and Cochrane Registry were searched for original papers with therapeutic hypothermia (TH) for treating neonatal encephalopathy in LMIC with no language restrictions. The search identified 1413 papers from 1990 to 31 August 2021.

RESULTS

Twenty-one original papers were included after duplicates removal and full-text screening in the final review. Fourteen randomized control studies and seven non-randomized studies were discussed with various modes of cooling (servo-controlled, phase changing material, traditional methods), complications during cooling, mortality and long-term neurodevelopmental assessment. Although there is sufficient evidence in LMIC favouring cooling for the reduction in mortality and improving the neurodevelopmental outcomes, nonetheless these studies were widely heterogeneous in terms of method of cooling, tools for assessing developmental outcomes, age at assessment and variations in neuroimaging tools and reporting.

CONCLUSION

Therapeutic hypothermia is beneficial in LMICs with low certainty of evidence in reducing mortality and improving neurodevelopmental outcomes.

Therapeutic Hypothermia for Neonatal Encephalopathy in Low- and Middle-Income Countries: A Meta-Analysis

BACKGROUND

Perinatal asphyxia and hypoxic-ischemic encephalopathy (HIE) represent substantial sources of neonatal morbidity and mortality in low- and middle-income countries (LMICs), leading to high rates of adverse long-term neurological outcomes.

METHODS

A systematic review with meta-analysis of randomized controlled trials in LMICs was conducted. PubMed, Scopus, Web of Science, CENTRAL, ClinicalTrials.gov, and Google Scholar were searched from inception to August 20, 2021. The population of the study consisted of neonates with gestational age ≥34 weeks and HIE. The main endpoints were overall mortality and the composite outcome of death or severe disability. The certainty of evidence was evaluated with the GRADE approach.

RESULTS

Ten studies were included comprising 1,293 neonates. Some concerns of bias were raised due to the nonblinded nature of the intervention. The risk of death was similar between the two groups (risk ratio [RR]: 0.78, 95% confidence interval [CI]: 0.52-1.18). No significant differences were observed in the composite outcome of death or severe disability between the two groups (RR: 0.78, 95% CI: 0.56-1.10, very low quality of evidence). Furthermore, no significant differences were observed in the endpoints of sepsis, shock, acute kidney injury, major arrhythmia, and length of hospital stay. Therapeutic hypothermia was associated with significantly higher risk of thrombocytopenia (RR: 2.13, 95% CI: 1.34-3.38) and clinically significant hemorrhage (RR: 1.57, 95% CI: 1.25-1.97).

CONCLUSION

Therapeutic hypothermia probably results in little to no difference in clinical outcomes among neonates with HIE in LMICs. Further large-scale research targeting proper patient selection is needed to elucidate the utility of therapeutic hypothermia in resource-limited settings.

PROTOCOL REGISTRATION

The protocol of the study has been prospectively registered by Prospero, CRD42021272284.

Need for more evidence in the prevention and management of perinatal asphyxia and neonatal encephalopathy in low and middle-income countries: A call for action

Although low- and middle-income countries (LMICs) shoulder 90 % of the neonatal encephalopathy (NE) burden, there is very little evidence base for prevention or management of this condition in these settings. A variety of antenatal factors including socio-economic deprivation, undernutrition and sub optimal antenatal and intrapartum care increase the risk of NE, although little is known about the underlying mechanisms. Implementing interventions based on the evidence from high-income countries to LMICs, may cause more harm than benefit as shown by the increased mortality and lack of neuroprotection with cooling therapy in the hypothermia for moderate or severe NE in low and middle-income countries (HELIX) trial. Pooled data from pilot trials suggest that erythropoietin monotherapy reduces death and disability in LMICs, but this needs further evaluation in clinical trials. Careful attention to supportive care, including avoiding hyperoxia, hypocarbia, hypoglycemia, and hyperthermia, are likely to improve outcomes until specific neuroprotective or neurorestorative therapies available.

Rise and Fall of Therapeutic Hypothermia in Low-Resource Settings: Lessons from the HELIX Trial

In the past decade, therapeutic hypothermia using a variety of low-cost devices has been widely implemented in India and other low-and middle-income countries (LMIC) without adequate evidence of either safety or efficacy. The recently reported data from the world's largest cooling trial (HELIX - hypothermia for encephalopathy in low- and middle-income countries) in LMIC provides definitive evidence of harm of cooling therapy with increase in mortality (number to harm 9) and lack of neuroprotection. Although the HELIX participating centers were highly selected tertiary neonatal intensive care units in South Asia with facilities for invasive ventilation, cardiovascular support, and 3 Tesla magnetic resonance imaging (MRI), and the trial used state-of-the-art automated servo-controlled cooling devices, a therapy that is harmful under such optimal conditions cannot be safe in low-resource settings that cannot even afford servo-controlled cooling devices.The HELIX trial has set a new benchmark for conducting high quality randomized controlled trials in terms of research governance, consent, ethics, follow-up rates, and involvement of parents. The standard care for neonatal encephalopathy in LMIC should remain normothermia, with close attention to prevention of hyperthermia. There is no role for therapeutic hypothermia in LMIC as the efficacy of hypothermia is dependent on the population, and not merely on the level of neonatal intensive care facilities. Future research should explore timings and origins of brain injury and prevention of brain injury in LMIC, with a strong emphasis on academic research capacity building and patient and public engagement.

Effects of therapeutic hypothermia on death among asphyxiated neonates with hypoxic-ischemic encephalopathy: A systematic review and meta-analysis of randomized control trials

Background

Hypoxic perinatal brain injury is caused by lack of oxygen to baby’s brain and can lead to death or permanent brain damage. However, the effectiveness of therapeutic hypothermia in birth asphyxiated infants with encephalopathy is uncertain. This systematic review and meta-analysis was aimed to estimate the pooled relative risk of mortality among birth asphyxiated neonates with hypoxic-ischemic encephalopathy in a global context.

Methods

We used the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines to search randomized control trials from electronic databases (PubMed, Cochrane library, Google Scholar, MEDLINE, Embase, Scopus, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and meta register of Current Controlled Trials (mCRT)). The authors extracted the author’s name, year of publication, country, method of cooling, the severity of encephalopathy, the sample size in the hypothermic, and non-hypothermic groups, and the number of deaths in the intervention and control groups. A weighted inverse variance fixed-effects model was used to estimate the pooled relative risk of mortality. The subgroup analysis was done by economic classification of countries, methods of cooling, and cooling devices. Publication bias was assessed with a funnel plot and Eggers test. A sensitivity analysis was also done.

Results

A total of 28 randomized control trials with a total sample of 35, 92 (1832 hypothermic 1760 non-hypothermic) patients with hypoxic-ischemic encephalopathy were used for the analysis. The pooled relative risk of mortality after implementation of therapeutic hypothermia was found to be 0.74 (95%CI; 0.67, 0.80; I² = 0.0%; p<0.996). The subgroup analysis revealed that the pooled relative risk of mortality in low, low middle, upper-middle and high income countries was 0.32 (95%CI; -0.95, 1.60; I² = 0.0%; p<0.813), 0.5 (95%CI; 0.14, 0.86; I² = 0.0%; p<0.998), 0.62 (95%CI; 0.41–0.83; I² = 0.0%; p<0.634) and 0.76 (95%CI; 0.69–0.83; I² = 0.0%; p<0.975) respectively. The relative risk of mortality was the same in selective head cooling and whole-body cooling method which was 0.74. Regarding the cooling device, the pooled relative risk of mortality is the same between the cooling cap and cooling blanket (0.74). However, it is slightly lower (0.73) in a cold gel pack.

Conclusions

Therapeutic hypothermia reduces the risk of death in neonates with moderate to severe hypoxic-ischemic encephalopathy. Both selective head cooling and whole-body cooling method are effective in reducing the mortality of infants with this condition. Moreover, low income countries benefit the most from the therapy. Therefore, health professionals should consider offering therapeutic hypothermia as part of routine clinical care to newborns with hypoxic-ischemic encephalopathy especially in low-income countries.

Therapeutic hypothermia for neonatal hypoxic-ischaemic encephalopathy in India (THIN study): a randomised controlled trial

OBJECTIVE

To evaluate the neuroprotective effect of therapeutic hypothermia (TH) induced by phase changing material (PCM) on MRI biomarkers in infants with hypoxic-ischaemic encephalopathy (HIE) in a low-resource setting.

DESIGN

Open-label randomised controlled trial.

SETTING

One neonatal intensive care unit in a tertiary care centre in India.

PATIENTS

50 term/near-term infants admitted within 5 hours after birth with predefined physiological criteria and signs of moderate/severe HIE.

INTERVENTIONS

Standard care (n=25) or standard care plus 72 hours of hypothermia (33.5°C±0.5°C, n=25) induced by PCM.

MAIN OUTCOME MEASURES

Primary outcome was fractional anisotropy (FA) in the posterior limb of the internal capsule (PLIC) on neonatal diffusion tensor imaging analysed according to intention to treat.

RESULTS

Primary outcome was available for 22 infants (44%, 11 in each group). Diffusion tensor imaging showed significantly higher FA in the cooled than the non-cooled infants in left PLIC and several white matter tracts. After adjusting for sex, birth weight and gestational age, the mean difference in PLIC FA between groups was 0.026 (95% CI 0.004 to 0.048, p=0.023). Conventional MRI was available for 46 infants and demonstrated significantly less moderate/severe abnormalities in the cooled (n=2, 9%) than in the non-cooled (n=10, 43%) infants. There was no difference in adverse events between groups.

CONCLUSIONS

This study confirmed that TH induced by PCM reduced brain injury detected on MRI in infants with moderate HIE in a neonatal intensive care unit in India. Future research should focus on optimal supportive treatment during hypothermia rather than looking at efficacy of TH in low-resource settings.

TRIAL REGISTRATION NUMBER

CTRI/2013/05/003693.

Free radicals and neonatal encephalopathy: mechanisms of injury, biomarkers, and antioxidant treatment perspectives

Neonatal encephalopathy (NE), most commonly a result of the disruption of cerebral oxygen delivery, is the leading cause of neurologic disability in term neonates. Given the key role of free radicals in brain injury development following hypoxia-ischemia-reperfusion, several oxidative biomarkers have been explored in preclinical and clinical models of NE. Among these, antioxidant enzyme activity, uric acid excretion, nitric oxide, malondialdehyde, and non-protein-bound iron have shown promising results as possible predictors of NE severity and outcome. Owing to high costs and technical complexity, however, their routine use in clinical practice is still limited. Several strategies aimed at reducing free radical production or upregulating physiological scavengers have been proposed for NE. Room-air resuscitation has proved to reduce oxidative stress following perinatal asphyxia and is now universally adopted. A number of medications endowed with antioxidant properties, such as melatonin, erythropoietin, allopurinol, or N-acetylcysteine, have also shown potential neuroprotective effects in perinatal asphyxia; nevertheless, further evidence is needed before these antioxidant approaches could be implemented as standard care.

Interventions targeted at oxidatively generated modifications of nucleic acids focused on urine and plasma markers

Oxidative stress is associated with the development and progression of numerous diseases. However, targeting oxidative stress has not been established in the clinical management of any disease. Several methods and markers are available to measure oxidative stress, including direct measurement of free radicals, antioxidants, redox balance, and oxidative modifications of cellular macromolecules. Oxidatively generated nucleic acid modifications have attracted much interest due to the pre-mutagenic oxidative modification of DNA into 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), associated with cancer development. During the last decade, the perception of RNA has changed from that of a 'silent messenger' to an 'active contributor', and, parallelly oxidatively generated RNA modifications measured as 8-oxo-7,8-dihydro-guanosine (8-oxoGuo), has been demonstrated as a prognostic factor for all-caused and cardiovascular related mortality in patients with type 2 diabetes. Several attempts have been made to modify the amount of oxidative nucleic acid modifications. Thus, this review aims to introduce researchers to the measurement of oxidatively generated nucleic acid modifications as well as critically review previous attempts and provide future directions for targeting oxidatively generated nucleic acid modifications.

Comparative Efficacy and Safety of Neuroprotective Therapies for Neonates With Hypoxic Ischemic Encephalopathy: A Network Meta-Analysis

Context: Several interventions are available for the management of hypoxic ischemic encephalopathy (HIE), but no studies have compared their relative efficacy in a single analysis. This study aims to compare and determine the effectiveness of available interventions for HIE using direct and indirect data.

Methods: Large randomized trials were identified from PubMed, EMBASE, CINAHL Plus, AMED, and Cochrane Library of Clinical Trials database from inception until June 30, 2018. Two independent reviewers extracted study data and performed quality assessment. Direct and network meta-analysis of randomized controlled trials was performed to obtained pooled results comparing the effectiveness of different therapies used in HIE on mortality, neurodevelopmental delay at 18 months, as well as adverse events. Their probability of having the highest efficacy and safety was estimated and ranked. The certainty of evidence for the primary outcomes of mortality and mortality or neurodevelopmental delay at 18 months was evaluated using GRADE criteria.

Results: Fifteen studies comparing five interventions were included in the network meta-analysis. Whole body cooling [Odds ratio: 0.62 (95% credible interval: 0.46–0.83); 8 trials, high certainty of evidence] was the most effective treatment in reducing the risk of mortality, followed by selective head cooling (0.73; 0.48–1.11; 2 trials, moderate certainty of evidence) and use of magnesium sulfate (0.79; 0.20–3.06; 2 trials, low certainty of evidence). Whole body hypothermia (0.48; 0.33–0.71; 5 trials), selective head hypothermia (0.54; 0.32–0.89; 2 trials), and erythropoietin (0.36; 0.19–0.66; 2 trials) were more effective for reducing the risk of mortality and neurodevelopmental delay at 18 months (moderate to high certainty). Among neonates treated for HIE, the use of erythropoietin (0.36; 0.18–0.74, 2 trials) and whole body hypothermia (0.61; 0.45–0.83; 7 trials) were associated with lower rates of cerebral palsy. Similarly, there were lower rates of seizures among neonates treated with erythropoietin (0.35; 0.13–0.94; 1 trial) and whole body hypothermia (0.64; 0.46–0.87, 7 trials).

Conclusion: The findings support current guidelines using therapeutic hypothermia in neonates with HIE. However, more trials are needed to determine the role of adjuvant therapy to hypothermia in reducing the risk of mortality and/or neurodevelopmental delay.

Neonatal Ogg1/Mutyh knockout mice have altered inflammatory gene response compared to wildtype mice in the brain and lung after hypoxia-reoxygenation

Background 8-Oxoguanine DNA-glycosylase 1 (OGG1) and mutY DNA glycosylase (MUTYH) are crucial in the repair of the oxidative DNA lesion 7,8-dihydro-8-oxoguanine caused by hypoxia-reoxygenation injury. Our objective was to compare the gene expression changes after hypoxia-reoxygenation in neonatal Ogg1-Mutyh double knockout mice (OM) and wildtype mice (WT), and study the gene response in OM after hyperoxic reoxygenation compared to normoxic. Methods Postnatal day 7 mice were subjected to 2 h of hypoxia (8% O2) followed by reoxygenation in either 60% O2 or air, and sacrificed right after completed reoxygenation (T0h) or after 72 h (T72h). The gene expression of 44 a priori selected genes was examined in the hippocampus/striatum and lung. Results We found that OM had an altered gene response compared to WT in 21 genes in the brain and 24 genes in the lung. OM had a lower expression than WT of inflammatory genes in the brain at T0h, and higher expression at T72h in both the brain and lung. In the lung of OM, five genes were differentially expressed after hyperoxic reoxygenation compared to normoxic. Conclusion For the first time, we report that Ogg1 and Mutyh in combination protect against late inflammatory gene activation in the hippocampus/striatum and lung after neonatal hypoxia-reoxygenation.

Hypothermia for encephalopathy in low-income and middle-income countries: feasibility of whole-body cooling using a low-cost servo-controlled device

Although therapeutic hypothermia (TH) is the standard of care for hypoxic ischaemic encephalopathy in high-income countries, the safety and efficacy of this therapy in low-income and middle-income countries (LMICs) is unknown. We aimed to describe the feasibility of TH using a low-cost servo-controlled cooling device and the short-term outcomes of the cooled babies in LMIC.

DESIGN

We recruited babies with moderate or severe hypoxic ischaemic encephalopathy (aged <6 hours) admitted to public sector tertiary neonatal units in India over a 28-month period. We administered whole-body cooling (set core temperature 33.5°C) using a servo-controlled device for 72 hours, followed by passive rewarming. We collected the data on short-term neonatal outcomes prior to hospital discharge.

RESULTS

Eighty-two babies were included-61 (74%) had moderate and 21 (26%) had severe encephalopathy. Mean (SD) hypothermia cooling induction time was 1.7 hour (1.5) and the effective cooling time 95% (0.08). The mean (SD) hypothermia induction time was 1.7 hour (1.5 hour), core temperature during cooling was 33.4°C (0.2), rewarming rate was 0.34°C (0.16°C) per hour and the effective cooling time was 95% (8%). Twenty-five (51%) babies had gastric bleeds, 6 (12%) had pulmonary bleeds and 21 (27%) had meconium on delivery. Fifteen (18%) babies died before discharge from hospital. Heart rate more than 120 bpm during cooling (P=0.01) and gastric bleeds (P<0.001) were associated with neonatal mortality.

CONCLUSIONS

The low-cost servo-controlled cooling device maintained the core temperature well within the target range. Adequately powered clinical trials are required to establish the safety and efficacy of TH in LMICs.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01760629.

Safety of Moderate Hypothermia for Perinatal Hypoxic-Ischemic Encephalopathy: A Meta-analysis

BACKGROUND

We investigated the safety of therapeutic hypothermia during intervention in infants with hypoxic-ischemic encephalopathy (HIE).

METHODS

The MEDLINE, EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials from onset to November 30, 2016 were searched for studies on perinatal HIE. Randomized controlled trials comparing the use of therapeutic hypothermia with normothermia for perinatal HIE were included in the study. Safety and efficacy data for therapeutic hypothermia in 1806 infants with HIE were included in this meta-analysis. The primary outcomes were safety variables, and the secondary outcomes were efficacy variables. A fixed-effect model was used to perform the meta-analysis. Risk ratios (RR), risk differences (RD), and 95% confidence intervals (CI) were calculated.

RESULTS

Thirteen trials, including 1806 infants, contained information on safety and efficacy variables. Moderate hypothermia significantly increased the risk of thrombocytopenia (RR 1.18, 95% CI 1.02 to 1.37, P = 0.03; RD 0.06, 95% CI -0.02 to 0.09) and cardiac arrhythmia (RR 2.52, 95% CI 1.62 to 3.93, P < 0.0001; RD 0.19, 95% CI 0.09 to 0.03) during intervention.

CONCLUSIONS

In infants with HIE, the application of therapeutic hypothermia increases the risk of thrombocytopenia and cardiac arrhythmia during intervention.

Effect of therapeutic hypothermia on myocardial dysfunction in term neonates with perinatal asphyxia - a randomized controlled trial

OBJECTIVE

To evaluate the effect of therapeutic hypothermia on myocardial dysfunction in term neonates with perinatal asphyxia.

MATERIAL AND METHODS

This randomized controlled trial (RCT) conducted in a tertiary care teaching hospital, south India included 120 newborns with perinatal asphyxia that were randomized to two groups (therapeutic hypothermia and normothermia). Cardiac enzyme profile changes between groups were assessed at 0, 24, 72 h CPK-MB and troponin I levels were estimated by immune inhibition and quantitative immunochromatography methods, respectively. Electrocardiography (ECG) and Echocardiography (ECHO) were done at 0 and 72 h to evaluate the cardiac function and pulmonary hypertension. Neurodevelopment was assessed at 6 months of age in both groups using Developmental Assessment Scales for Indian Infants.

RESULTS

The median values of CPK-MB in the normothermia and hypothermia groups at 0, 24, and 72 h were 198, 127, and 92 IU/L and 202, 111 and 64 IU/L, respectively. The median values of troponin I in normothermia and hypothermia groups at 0, 24, and 72 hrs were 2.45, 1.53, and 0.9 ng/mL and 1.97, 0.93, and 0.01 ng/mL, respectively. ECG and ECHO findings also suggest lesser myocardial dysfunction in therapeutic hypothermia group compared with the normothermia group.

CONCLUSIONS

Therapeutic hypothermia significantly decreases the myocardial damage in term asphyxiated neonates.

Does therapeutic hypothermia reduce acute kidney injury among term neonates with perinatal asphyxia?--a randomized controlled trial

OBJECTIVE

The objective of this study is to evaluate whether therapeutic hypothermia reduces the incidence of acute kidney injury (AKI) among term neonates perinatal asphyxia.

METHODS

This randomized controlled trial conducted in a tertiary care teaching hospital, south India included 120 term neonates with perinatal asphyxia who were randomized to receive either therapeutic hypothermia or standard supportive care. Renal parameters of neonates in both the groups were monitored and AKI was ascertained as per Acute Kidney Injury Network criteria.

RESULTS

The incidence of AKI was less in therapeutic hypothermia group compared to standard treatment group (32% versus 60%, p < 0.05). The incidence of Stages 1, 2, and 3 AKI was 22%, 5%, and 5% in therapeutic hypothermia group compared with 52%, 5%, and 3%, respectively, in the standard treatment group. The mortality was less in therapeutic hypothermia group compared with the standard treatment group (26% versus 50%, p < 0.05).

CONCLUSION

Therapeutic hypothermia reduces the incidence and severity of AKI among term neonates with perinatal asphyxia.

Cooling in a low-resource environment: lost in translation

Although cooling therapy has been the standard of care for neonatal encephalopathy (NE) in high-income countries for more than half a decade, it is still not widely used in low- and middle-income countries (LMIC), which bear 99% of the encephalopathy burden; neither is it listed as a priority research area in global health. Here we explore the major roadblocks that prevent the use of cooling in LMIC, including differences in population comorbidities, suboptimal intensive care, and the lack of affordable servo-controlled cooling devices. The emerging data from LMIC suggest that the incidence of coexisting perinatal infections in NE is no different to that in high-income countries, and that cooling can be effectively provided without tertiary intensive care and ventilatory support; however, the data on safety and efficacy of cooling are limited. Without adequately powered clinical trials, the creeping and uncertain introduction of cooling therapy in LMIC will be plagued by residual safety concerns, and any therapeutic benefit will be even more difficult to translate into widespread clinical use.

Therapeutic cooling for perinatal asphyxia-Indian experience

Therapeutic hypothermia (TH) has been established as standard of care for term babies with perinatal asphyxia in developed countries. However, it is yet to gain momentum in India. This review summarizes some of the TH trials conducted in India and the various related issues in adapting the same for the Indian context.