Prophylactic barbiturate use for the prevention of morbidity and mortality following perinatal asphyxia

Additive interaction between birth asphyxia and febrile seizures on autism spectrum disorder: a population-based study

BACKGROUND

Autism Spectrum Disorder (ASD) is a pervasive neurodevelopmental disorder that can significantly impact an individual's ability to socially integrate and adapt. It's crucial to identify key factors associated with ASD. Recent studies link both birth asphyxia (BA) and febrile seizures (FS) separately to higher ASD prevalence. However, investigations into the interplay of BA and FS and its relationship with ASD are yet to be conducted. The present study mainly focuses on exploring the interactive effect between BA and FS in the context of ASD.

METHODS

Utilizing a multi-stage stratified cluster sampling, we initially recruited 84,934 Shanghai children aged 3-12 years old from June 2014 to June 2015, ultimately including 74,251 post-exclusion criteria. A logistic regression model was conducted to estimate the interaction effect after controlling for pertinent covariates. The attributable proportion (AP), the relative excess risk due to interaction (RERI), the synergy index (SI), and multiplicative-scale interaction were computed to determine the interaction effect.

RESULTS

Among a total of 74,251 children, 192 (0.26%) were diagnosed with ASD. The adjusted odds ratio for ASD in children with BA alone was 3.82 (95% confidence interval [CI] 2.42-6.02), for FS alone 3.06 (95%CI 1.48-6.31), and for comorbid BA and FS 21.18 (95%CI 9.10-49.30), versus children without BA or FS. The additive interaction between BA and FS showed statistical significance (P < 0.001), whereas the multiplicative interaction was statistically insignificant (P > 0.05).

LIMITATIONS

This study can only demonstrate the relationship between the interaction of BA and FS with ASD but cannot prove causation. Animal brain experimentation is necessary to unravel its neural mechanisms. A larger sample size, ongoing monitoring, and detailed FS classification are needed for confirming BA-FS interaction in ASD.

CONCLUSION

In this extensive cross-sectional study, both BA and FS were significantly linked to ASD. The coexistence of these factors was associated with an additive increase in ASD prevalence, surpassing the cumulative risk of each individual factor.

Grading the level of evidence of neonatal pharmacotherapy: midazolam and phenobarbital as examples

BACKGROUND

Many drugs are used off-label or unlicensed in neonates. This does not mean they are used without evidence or knowledge. We aimed to apply and evaluate the Grading and Assessment of Pharmacokinetic-Pharmacodynamic Studies (GAPPS) scoring system for the level of evidence of two commonly used anti-epileptic drugs.

METHODS

Midazolam and phenobarbital as anti-epileptics were evaluated with a systematic literature search on neonatal pharmacokinetic (PK) and/or pharmacodynamic [PD, (amplitude-integrated) electroencephalography effect] studies. With the GAPPS system, two evaluators graded the current level of evidence. Inter-rater agreement was assessed for dosing evidence score (DES), quality of evidence (QoE), and strength of recommendation (REC).

RESULTS

Seventy-two studies were included. DES scores 4 and 9 were most frequently used for PK, and scores 0 and 1 for PD. Inter-rater agreements on DES, QoE, and REC ranged from moderate to very good. A final REC was provided for all PK studies, but only for 25% (midazolam) and 33% (phenobarbital) of PD studies.

CONCLUSIONS

There is a reasonable level of evidence concerning midazolam and phenobarbital PK in neonates, although using a predefined target without integrated PK/PD evaluation. Further research is needed on midazolam use in term neonates with therapeutic hypothermia, and phenobarbital treatment in preterms.

IMPACT

There is a reasonable level of evidence concerning pharmacotherapy of midazolam and phenobarbital in neonates. Most evidence is however based on PK studies, using a predefined target level or concentration range without integrated, combined PK/PD evaluation. Using the GAPPS system, final strength of recommendation could be provided for all PK studies, but only for 25% (midazolam) to 33% (phenobarbital) of PD studies. Due to the limited PK observations of midazolam in term neonates with therapeutic hypothermia, and of phenobarbital in preterm neonates these subgroups can be identified for further research.

Pharmacological interventions for pain and sedation management in newborn infants undergoing therapeutic hypothermia

BACKGROUND

Newborn infants affected by hypoxic-ischemic encephalopathy (HIE) undergo therapeutic hypothermia. As this treatment seems to be associated with pain, and intensive and invasive care is needed, pharmacological interventions are often used. Moreover, painful procedures in the newborn period can affect pain responses later in life, impair brain development, and possibly have a long-term negative impact on neurodevelopment and quality of life.

OBJECTIVES

To determine the effects of pharmacological interventions for pain and sedation management in newborn infants undergoing therapeutic hypothermia. Primary outcomes were analgesia and sedation, and all-cause mortality to discharge.

SEARCH METHODS

We searched CENTRAL, PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and the trial register ISRCTN in August 2021. We also checked the reference lists of relevant articles to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCT), quasi-RCTs and cluster-randomized trials comparing drugs used for the management of pain or sedation, or both, during therapeutic hypothermia: any opioids (e.g. morphine, fentanyl), alpha-2 agonists (e.g. clonidine, dexmedetomidine), N-Methyl-D-aspartate (NMDA) receptor antagonist (e.g. ketamine), other analgesics (e.g. paracetamol), and sedatives (e.g. benzodiazepines such as midazolam) versus another drug, placebo, no intervention, or non-pharmacological interventions.  Primary outcomes were analgesia and sedation, and all-cause mortality to discharge.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified by the search strategy for inclusion. We planned to use the GRADE approach to assess the certainty of evidence. We planned to assess the methodological quality of included trials using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria (assessing randomization, blinding, loss to follow-up, and handling of outcome data). We planned to evaluate treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean, standard deviation (SD), and mean difference (MD) for continuous data.  MAIN RESULTS: We did not find any completed studies for inclusion. Amongst the four excluded studies, topiramate and atropine were used in two and one trial, respectively; one study used dexmedetomidine and was initially reported in 2019 to be a randomized trial. However, it was an observational study (correction in 2021). We identified one ongoing study comparing dexmedetomidine to morphine.

AUTHORS' CONCLUSIONS

We found no studies that met our inclusion criteria and hence there is no evidence to recommend or refute the use of pharmacological interventions for pain and sedation management in newborn infants undergoing therapeutic hypothermia.

Tocolysis in the management of preterm prelabor rupture of membranes at 22-33 weeks of gestation: study protocol for a multicenter, double-blind, randomized controlled trial comparing nifedipine with placebo (TOCOPROM)

Background

Preterm prelabor rupture of membranes (PPROM) before 34 weeks of gestation complicates 1% of pregnancies and accounts for one-third of preterm births. International guidelines recommend expectant management, along with antenatal steroids before 34 weeks and antibiotics. Up-to-date evidence about the risks and benefits of administering tocolysis after PPROM, however, is lacking. In theory, reducing uterine contractility could delay delivery and reduce the risks of prematurity and its adverse short- and long-term consequences, but it might also prolong fetal exposure to inflammation, infection, and acute obstetric complications, potentially associated with neonatal death or long-term sequelae. The primary objective of this study is to assess whether short-term (48 h) tocolysis reduces perinatal mortality/morbidity in PPROM at 22 to 33 completed weeks of gestation.

Methods

A randomized, double-blind, placebo-controlled, superiority trial will be performed in 29 French maternity units. Women with PPROM between 22^0/7 and 33^6/7 weeks of gestation, a singleton pregnancy, and no condition contraindicating expectant management will be randomized to receive a 48-hour oral treatment by either nifedipine or placebo (1:1 ratio). The primary outcome will be the occurrence of perinatal mortality/morbidity, a composite outcome including fetal death, neonatal death, or severe neonatal morbidity before discharge. If we assume an alpha-risk of 0.05 and beta-risk of 0.20 (i.e., a statistical power of 80%), 702 women (351 per arm) are required to show a reduction of the primary endpoint from 35% (placebo group) to 25% (nifedipine group). We plan to increase the required number of subjects by 20%, to replace any patients who leave the study early. The total number of subjects required is thus 850. Data will be analyzed by the intention-to-treat principle.

Discussion

This trial will inform practices and policies worldwide. Optimized prenatal management to improve the prognosis of infants born preterm could benefit about 50,000 women in the European Union and 40,000 in the United States each year.

Trial registration

ClinicalTrials.gov identifier: NCT03976063 (registration date June 5, 2019).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04047-2.

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

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

Perspectives from the Society for Pediatric Research. Neonatal encephalopathy clinical trials: developing the future

The next phase of clinical trials in neonatal encephalopathy (NE) focuses on hypothermia adjuvant therapies targeting alternative recovery mechanisms during the process of hypoxic brain injury. Identifying infants eligible for neuroprotective therapies begins with the clinical detection of brain injury and classification of severity. Combining a variety of biomarkers (serum, clinical exam, EEG, movement patterns) with innovative clinical trial design and analyses will help target infants with the most appropriate and timely treatments. The timing of magnetic resonance imaging (MRI) and MR spectroscopy after NE both assists in identifying the acute perinatal nature of the injury (days 3-7) and evaluates the full extent and evolution of the injury (days 10-21). Early, intermediate outcome of neuroprotective interventions may be best defined by the 21-day neuroimaging, with recognition that the full neurodevelopmental trajectory is not yet defined. An initial evaluation of each new therapy at this time point may allow higher-throughput selection of promising therapies for more extensive investigation. Functional recovery can be assessed using a trajectory of neurodevelopmental evaluations targeted to a prespecified and mechanistically derived hypothesis of drug action. As precision medicine revolutionizes healthcare, it should also include the redesign of NE clinical trials to allow safe, efficient, and targeted therapeutics. IMPACT: As precision medicine revolutionizes healthcare, it should also include the redesign of NE clinical trials to allow faster development of safe, effective, and targeted therapeutics. This article provides a multidisciplinary perspective on the future of clinical trials in NE; novel trial design; study management and oversight; biostatistical methods; and a combination of serum, imaging, and neurodevelopmental biomarkers can advance the field and improve outcomes for infants affected by NE. Innovative clinical trial designs, new intermediate trial end points, and a trajectory of neurodevelopmental evaluations targeted to a prespecified and mechanistically derived hypothesis of drug action can help address common challenges in NE clinical trials and allow for faster selection and validation of promising therapies for more extensive investigation.

A pilot protocol and review of triple neuroprotection with targeted hypothermia, controlled induced hypertension, and barbiturate infusion during emergency carotid endarterectomy for acute stroke after failed tPA or beyond 24-hour window of opportunity

An alternative to tissue plasminogen activator (tPA) failure has been a daunting challenge in ischemic stroke management. As tPA is time-dependent, delays can occur in definitive treatment while passively waiting to observe a clinical response to intravenous thrombolysis. Until today, uncertainty exists in the management strategy of wake-up stroke patients or those presenting beyond the therapeutic tPA window. Clinical dilemmas in these situations can prolong the transitional period of inertia, resulting in an adverse neurological outcome. We propose and review an innovative approach called triple neuro-protection (TNP), which encompasses three technical domains-targeted hypothermia, systemic induced hypertension, and barbiturates infusion, to protect the brain during carotid endarterectomy after failed tPA and/or beyond the 24-hour therapeutic mechanical thrombectomy window. This proposal assimilates discussion on the clinical evidence of the individual domains of TNP with our own clinical experience with TNP. Our first TNP was successfully employed in a 55-year-old man in 2015 while performing emergency carotid endarterectomy after he was referred to us 72 hours post tPA failure. The patient had a successful clinical outcome despite being in therapeutic inertia with 90–99% ipsilateral carotid stenosis and contralateral occlusion on presentation. In the last five years, we have safely used TNP in 25 selected cases with favourable clinical outcomes.

Practice variation in anti-epileptic drug use for neonatal hypoxic-ischemic encephalopathy among regional NICUs

Background

While intercenter variation (ICV) in anti-epileptic drug (AED) use in neonates with seizures has been previously reported, variation in AED practices across regional NICUs has not been specifically and systematically evaluated. This is important as these centers typically have multidisciplinary neonatal neurocritical care teams and protocolized approaches to treating conditions such as hypoxic ischemic encephalopathy (HIE), a population at high risk for neonatal seizures. To identify opportunities for quality improvement (QI), we evaluated ICV in AED utilization for neonates with HIE treated with therapeutic hypothermia (TH) across regional NICUs in the US.

Methods

Children’s Hospital Neonatal Database and Pediatric Health Information Systems data were linked for 1658 neonates ≥36 weeks’ gestation, > 1800 g birthweight, with HIE treated with TH, from 20 NICUs, between 2010 and 2016. ICV in AED use was evaluated using a mixed-effect regression model. Rates of AED exposure, duration, prescription at discharge and standardized AED costs per patient were calculated as different measures of utilization.

Results

Ninety-five percent (range: 83–100%) of patients with electrographic seizures, and 26% (0–81%) without electrographic seizures, received AEDs. Phenobarbital was most frequently used (97.6%), followed by levetiracetam (16.9%), phenytoin/fosphenytoin (15.6%) and others (2.4%; oxcarbazepine, topiramate and valproate). There was significant ICV in all measures of AED utilization. Median cost of AEDs per patient was $89.90 (IQR $24.52,$258.58).

Conclusions

Amongst Children’s Hospitals, there is marked ICV in AED utilization for neonatal HIE. Variation was particularly notable for HIE patients without electrographic seizures, indicating that this population may be an appropriate target for QI processes to harmonize neuromonitoring and AED practices across centers.

Neonatal interventions for preventing cerebral palsy: an overview of Cochrane Systematic Reviews

BACKGROUND

Cerebral palsy is an umbrella term that encompasses disorders of movement and posture attributed to non-progressive disturbances occurring in the developing foetal or infant brain. As there are diverse risk factors and aetiologies, no one strategy will prevent cerebral palsy. Therefore, there is a need to systematically consider all potentially relevant interventions for prevention.

OBJECTIVES

PrimaryTo summarise the evidence from Cochrane Systematic Reviews regarding effects of neonatal interventions for preventing cerebral palsy (reducing cerebral palsy risk).SecondaryTo summarise the evidence from Cochrane Systematic Reviews regarding effects of neonatal interventions that may increase cerebral palsy risk.

METHODS

We searched the Cochrane Database of Systematic Reviews (27 November 2016) for reviews of neonatal interventions reporting on cerebral palsy. Two review authors assessed reviews for inclusion, extracted data, and assessed review quality (using AMSTAR and ROBIS) and quality of the evidence (using the GRADE approach). Reviews were organised by topic; findings were summarised in text and were tabulated. Interventions were categorised as effective (high-quality evidence of effectiveness); possibly effective (moderate-quality evidence of effectiveness); ineffective (high-quality evidence of harm); probably ineffective (moderate-quality evidence of harm or lack of effectiveness); and no conclusions possible (low- to very low-quality evidence).

MAIN RESULTS

Forty-three Cochrane Reviews were included. A further 102 reviews pre-specified the outcome cerebral palsy, but none of the included randomised controlled trials (RCTs) reported this outcome. Included reviews were generally of high quality and had low risk of bias, as determined by AMSTAR and ROBIS. These reviews involved 454 RCTs; data for cerebral palsy were available from 96 (21%) RCTs involving 15,885 children. Review authors considered interventions for neonates with perinatal asphyxia or with evidence of neonatal encephalopathy (3); interventions for neonates born preterm and/or at low or very low birthweight (33); and interventions for other specific groups of 'at risk' neonates (7). Quality of evidence (GRADE) ranged from very low to high.Interventions for neonates with perinatal asphyxia or with evidence of neonatal encephalopathyEffective interventions: high-quality evidence of effectivenessResearchers found a reduction in cerebral palsy following therapeutic hypothermia versus standard care for newborns with hypoxic ischaemic encephalopathy (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.54 to 0.82; seven trials; 881 children).No conclusions possible: very low-quality evidenceOne review observed no clear differences in cerebral palsy following therapeutic hypothermia versus standard care.Interventions for neonates born preterm and/or at low or very low birthweightPossibly effective interventions: moderate-quality evidence of effectivenessResearchers found a reduction in cerebral palsy with prophylactic methylxanthines (caffeine) versus placebo for endotracheal extubation in preterm infants (RR 0.54, 95% CI 0.32 to 0.92; one trial; 644 children).Probably ineffective interventions: moderate-quality evidence of harmResearchers reported an increase in cerebral palsy (RR 1.45, 95% CI 1.06 to 1.98; 12 trials; 1452 children) and cerebral palsy in assessed survivors (RR 1.50, 95% CI 1.13 to 2.00; 12 trials; 959 children) following early (at less than eight days of age) postnatal corticosteroids versus placebo or no treatment for preventing chronic lung disease in preterm infants.Probably ineffective interventions: moderate-quality evidence of lack of effectivenessTrial results showed no clear differences in cerebral palsy following ethamsylate versus placebo for prevention of morbidity and mortality in preterm or very low birthweight infants (RR 1.13, 95% CI 0.64 to 2.00; three trials, 532 children); volume expansion versus no treatment (RR 0.76, 95% CI 0.48 to 1.20; one trial; 604 children); gelatin versus fresh frozen plasma (RR 0.94, 95% CI 0.52 to 1.69; one trial, 399 children) for prevention of morbidity and mortality in very preterm infants; prophylactic indomethacin versus placebo for preventing mortality and morbidity in preterm infants (RR 1.04, 95% CI 0.77 to 1.40; four trials; 1372 children); synthetic surfactant versus placebo for respiratory distress syndrome in preterm infants (RR 0.76, 95% CI 0.55 to 1.05; five trials; 1557 children); or prophylactic phototherapy versus standard care (starting phototherapy when serum bilirubin reached a pre-specified level) for preventing jaundice in preterm or low birthweight infants (RR 0.96, 95% CI 0.50 to 1.85; two trials; 756 children).No conclusions possible: low- to very low-quality evidenceNo clear differences in cerebral palsy were observed with interventions assessed in 21 reviews.Interventions for other specific groups of 'at risk' neonatesNo conclusions possible: low- to very low-quality evidenceReview authors observed no clear differences in cerebral palsy with interventions assessed in five reviews.

AUTHORS' CONCLUSIONS

This overview summarises evidence from Cochrane Systematic Reviews regarding effects of neonatal interventions on cerebral palsy, and can be used by researchers, funding bodies, policy makers, clinicians, and consumers to aid decision-making and evidence translation. To formally assess other benefits and/or harms of included interventions, including impact on risk factors for cerebral palsy, review of the included Reviews is recommended.Therapeutic hypothermia versus standard care for newborns with hypoxic ischaemic encephalopathy can prevent cerebral palsy, and prophylactic methylxanthines (caffeine) versus placebo for endotracheal extubation in preterm infants may reduce cerebral palsy risk. Early (at less than eight days of age) postnatal corticosteroids versus placebo or no treatment for preventing chronic lung disease in preterm infants may increase cerebral palsy risk.Cerebral palsy is rarely identified at birth, has diverse risk factors and aetiologies, and is diagnosed in approximately one in 500 children. To date, only a small proportion of Cochrane Systematic Reviews assessing neonatal interventions have been able to report on this outcome. There is an urgent need for long-term follow-up of RCTs of such interventions addressing risk factors for cerebral palsy (through strategies such as data linkage with registries) and for consideration of the use of relatively new interim assessments (including the General Movements Assessment). Such RCTs must be rigorous in their design and must aim for consistency in cerebral palsy outcome measurement and reporting to facilitate pooling of data and thus to maximise research efforts focused on prevention.

The use of phenobarbital and other anti-seizure drugs in newborns

Neonatal seizures constitute the most frequent presenting neurologic sign encountered in the neonatal intensive care unit. Despite limited efficacy and safety data, phenobarbital continues to be used near-universally as the first-line anti-seizure drug (ASD) in neonates. The choice of second-line ASDs varies by provider and institution, and is still not supported by sufficient scientific evidence. In this review, we discuss the available evidence supporting the efficacy, mechanism of action, potential adverse effects, key pharmacokinetic characteristics such as interaction with therapeutic hypothermia, logistical issues, and rationale for use of neonatal ASDs. We describe the widely used neonatal ASDs, namely phenobarbital, phenytoin, midazolam, and levetiracetam, in addition to potential ASDs, including lidocaine, topiramate, and bumetanide.

Ganaxolone: A New Treatment for Neonatal Seizures

Neonatal seizures are amongst the most common neurologic conditions managed by a neonatal care service. Seizures can exacerbate existing brain injury, induce “de novo” injury, and are associated with neurodevelopmental disabilities in post-neonatal life. In this mini-review, we present evidence in support of the use of ganaxolone, a GABA^A agonist neurosteroid, as a novel neonatal therapy. We discuss evidence that ganaxolone can provide both seizure control and neuroprotection with a high safety profile when administered early following birth-related hypoxia, and show evidence that it is likely to prevent or reduce the incidence of the enduring disabilities associated with preterm birth, cerebral palsy, and epilepsy. We suggest that ganaxolone is an ideal anti-seizure treatment because it can be safely used prospectively, with minimal or no adverse effects on the neonatal brain.