A systematic review of cooling for neuroprotection in neonates with hypoxic ischemic encephalopathy - are we there yet?

Temporal evolution of electrographic seizures in newborn infants with hypoxic-ischaemic encephalopathy requiring therapeutic hypothermia: a secondary analysis of the ANSeR studies

BACKGROUND

Despite extensive research on neonatal hypoxic-ischaemic encephalopathy, detailed information about electrographic seizures during active cooling and rewarming of therapeutic hypothermia is sparse. We aimed to describe temporal evolution of seizures and determine whether there is a correlation of seizure evolution with 2-year outcome.

METHODS

This secondary analysis included newborn infants recruited from eight European tertiary neonatal intensive care units for two multicentre studies (a randomised controlled trial [NCT02431780] and an observational study [NCT02160171]). Infants were born at 36+0 weeks of gestation with moderate or severe hypoxic-ischaemic encephalopathy and underwent therapeutic hypothermia with prolonged conventional video-electroencephalography (EEG) monitoring for 10 h or longer from the start of rewarming. Seizure burden characteristics were calculated based on electrographic seizures annotations: hourly seizure burden (minutes of seizures within an hour) and total seizure burden (minutes of seizures within the entire recording). We categorised infants into those with electrographic seizures during active cooling only, those with electrographic seizures during cooling and rewarming, and those without seizures. Neurodevelopmental outcomes were determined using the Bayley's Scales of Infant and Toddler Development, Third Edition (BSID-III), the Griffiths Mental Development Scales (GMDS), or neurological assessment. An abnormal outcome was defined as death or neurodisability at 2 years. Neurodisability was defined as a composite score of 85 or less on any subscales for BSID-III, a total score of 87 or less for GMDS, or a diagnosis of cerebral palsy (dyskinetic cerebral palsy, spastic quadriplegia, or mixed motor impairment) or epilepsy.

FINDINGS

Of 263 infants recruited between Jan 1, 2011, and Feb 7, 2017, we included 129 infants: 65 had electrographic seizures (43 during active cooling only and 22 during and after active cooling) and 64 had no seizures. Compared with infants with seizures during active cooling only, those with seizures during and after active cooling had a longer seizure period (median 12 h [IQR 3-28] vs 68 h [35-86], p<0·0001), more seizures (median 12 [IQR 5-36] vs 94 [24-134], p<0·0001), and higher total seizure burden (median 69 min [IQR 22-104] vs 167 min [54-275], p=0·0033). Hourly seizure burden peaked at about 20-24 h in both groups, and infants with seizures during and after active cooling had a secondary peak at 85 h of age. When combined, worse EEG background (major abnormalities and inactive background) at 12 h and 24 h were associated with the seizure group: compared with infants with a better EEG background (normal, mild, or moderate abnormalities), infants with a worse EEG background were more likely to have seizures after cooling at 12 h (13 [54%] of 24 vs four [14%] of 28; odds ratio 7·09 [95% CI 1·88-26·77], p=0·0039) and 24 h (14 [56%] of 25 vs seven [18%] of 38; 5·64 [1·81-17·60], p=0·0029). There was a significant relationship between EEG grade at 12 h (four categories) and seizure group (p=0·020). High total seizure burden was associated with increased odds of an abnormal outcome at 2 years of age (odds ratio 1·007 [95% CI 1·000-1·014], p=0·046), with a medium negative correlation between total seizure burden and BSID-III cognitive score (rS=-0·477, p=0·014, n=26).

INTERPRETATION

Overall, half of infants with hypoxic-ischaemic encephalopathy had electrographic seizures and a third of those infants had seizures beyond active cooling, with worse outcomes. These results raise the importance of prolonged EEG monitoring of newborn infants with hypoxic-ischaemic encephalopathy not only during active cooling but throughout the rewarming phase and even longer when seizures are detected.

FUNDING

Wellcome Trust, Science Foundation Ireland, and the Irish Health Research Board.

Protocol for a Magnetic Resonance Imaging (MRI) Study of Participants in the Fever Randomized Controlled Trial: Does fever control prevent brain injury in malaria?

Background

Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy.

Methods

This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury.

Discussion

Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

Aggressive antipyretics in central nervous system malaria: Study protocol of a randomized-controlled trial assessing antipyretic efficacy and parasite clearance effects (Malaria FEVER study)

BACKGROUND

Malaria remains a major public health challenge in Africa where annually, ~250,000 children with malaria experience a neurologic injury with subsequent neuro-disability. Evidence indicates that a higher temperature during the acute illness is a risk factor for post-infectious neurologic sequelae. As such, aggressive antipyretic therapy may be warranted among children with complicated malaria at substantial risk of brain injury. Previous clinical trials conducted primarily in children with uncomplicated malaria and using only a single antipyretic medication have shown limited benefits in terms of fever reduction; however, no studies to date have examined malaria fever management using dual therapies. In this clinical trial of aggressive antipyretic therapy, children hospitalized with central nervous system (CNS) malaria will be randomized to usual care (acetaminophen every 6 hours for a temperature ≥ 38.5°C) vs. prophylactic acetaminophen and ibuprofen every 6 hours for 72 hours.

METHODS

In this double-blinded, placebo controlled, two-armed clinical trial, we will enroll 284 participants from three settings at Queen Elizabeth Central Hospital in Blantyre, Malawi; at the University Teaching Hospitals Children's Hospital in Lusaka, Zambia and at Chipata Central Hospital, Chipata, Zambia. Parents or guardians must provide written informed consent. Eligible participants are 2-11 years with evidence of P. falciparum malaria infection by peripheral blood smear or rapid diagnostic test with CNS symptoms associated with malaria. Eligible children will receive treatment allocation randomization either to standard of care for fever management or to prophylactic, scheduled treatment every 6 hours for 72 hours with dual antipyretic therapies using acetaminophen and ibuprofen. Assignment to treatment groups will be with 1:1 allocation using blocked randomization. The primary outcome will be maximum temperature in the 72 hours after enrolment. Secondary outcomes include parasite clearance as determined by quantitative Histidine Rich Protein II and seizures through 72 hours after enrolment.

DISCUSSION

This clinical trial seeks to challenge the practice paradigm of limited fever treatment based upon hyperpyrexia by evaluating the fever-reduction efficacy of more aggressive antipyretic using two antipyretics and prophylactic administration and will elucidate the impact of antipyretics on parasite clearance and acute symptomatic seizures. If aggressive antipyretic therapy is shown to safely reduce the maximum temperature, a clinical trial evaluating the neuroprotective effects of temperature reduction in CNS malaria is warranted.

Trust and consent: a prospective study on parents' perspective during a neonatal trial

OBJECTIVE

This study aimed to describe how parents and physicians experienced the informed consent interview and to investigate the aspects of the relationship that influenced parents' decision during the consent process for a randomised clinical trial in a tertiary neonatal intensive care unit (NICU). The secondary objective was to describe the perspectives of parents and physicians in the specific situation of prenatal informed consent.

SETTING

Single centre study in NICU of the Centre Hospitalier Intercommunal de Créteil, France, using a convenience period from February to May 2016.

DESIGN

Ancillary study to a randomised clinical trial: Prettineo. Records of interviews for consent.

POPULATION

parents and physicians. Mixed study including qualitative and quantitative interview data about participants' recall and feelings about the consent process. Interviews were reviewed using thematic discourse analysis.

RESULTS

Parents' recall and understanding of the study's main goal and design was good. Parents and physicians had a positive experience, and trust was one of the main reasons for parents to consent. Misunderstanding (bad comprehension) was the main reason for refusal.Before birth, three situations can compromise parents' consent: the mother already consented to participate in other studies, the absence of the father during the interview and the feeling that the baby's birth is not an imminent possibility.

CONCLUSIONS

Confronting parents and physicians' perspectives in research can help us reach answers to sensitive issues such as content and timing of information. Each different types of study raises different ethical dilemmas for consent that might be discussed in a more individual way.

Exogenous surfactant replacement immediately at birth as preventive therapy for lung prematurity in neonatal lambs

Surfactant treatment is a manner to reduce alveolar superficial tension and increase pulmonary compliance in premature neonates. Thus, we aimed to analyze the effect of exogenous surfactant treatment in combination with manual ventilation for preterm lambs. We used 15 ewes and their lambs (n = 16), prematurely born at 135 days. At birth, lambs were submitted to orotracheal intubation attached to a handheld resuscitation device and randomly allocated to: Control Group (n = 5; only manual ventilation), Single Surfactant Group (n = 5; manual ventilation coupled by intratracheal administration of 100 mg/kg surfactant) and Double Surfactant Group (n = 6; surfactant volume was divided into two doses (50 mg/kg + 50 mg/kg) administrated at birth and 30 min thereafter). A complete physical exam, arterial gas analysis, blood glucose, urea and creatinine concentration and chest radiographic assessment were performed at fixed times. All lambs had decreased body temperature until 20 min after birth. However, control and double surfactant groups reached a thermic plateau after 30 min. Regardless of the time-point, control lambs had higher heart rate in comparison to treated neonates, including bradycardia in Single Surfactant Group. Single instillation led to lower oxygenation degree, compared to the Double Surfactant Group, suggesting that surfactant treatment was not able to adequately spread within the alveoli. Lambs treated with surfactant had severe impairment of aerobic activity, leading to anaerobic metabolism. All groups had hypercapnia, which can be explained by inadequate respiratory pattern and pulmonary opacity (89% of the lambs had severe or moderate lung content). In conclusion, exogenous surfactant therapy in association with manual ventilation is ineffective in reverting pulmonary immaturity of the preterm lamb, leading to less vitality, hypoxemia, delayed pulmonary clearance and high mortality rate.

Hypothermic treatment for neonatal asphyxia in low-resource settings using phase-changing material-An easy to use and low-cost method

AIM

To evaluate whether phase-changing material can be used for therapeutic hypothermia of asphyxiated newborns in low-resource settings.

METHODS

Prospective interventional study of asphyxiated term infants fulfilling criteria for hypothermia treatment at Vietnam National Children's Hospital from September 2014 to September 2016. Hypothermia was induced within 6 hours after birth and maintained for 72 hours by a phase-changing material mattress with melting point of 32°C. Rectal temperature was continuously measured, and deviations from target temperature range 33.5-34.5°C were recorded.

RESULTS

In total 52 infants (mean gestational age 39.3 ± 1.1 weeks) included and cooled, the median temperature at initiation of cooling was 35.3 (IQR 34.5-35.9)°C. The median time to reach target temperature was 2.5 (IQR 2-3) hours. The mean temperature during the cooling phase was 33.95 ± 0.2°C. Throughout the cooling phase, the target temperature range (33.5-34.5°C) was maintained more than 80% of the time. Rate of rewarming was 0.5 ± 0.14°C/hour.

CONCLUSION

Phase-changing material can be used as an effective cooling method. Though not a servo-controlled system, it is easy to induce hypothermia, maintain target temperature and rewarm infants in a slow and controlled manner without need for frequent changes and minimum risk of skin injury.

Moderate Hypothermia Effectively Alleviates Acetaminophen-Induced Liver Injury With Prolonged Action Beyond Cooling

Acetaminophen (APAP) overdose accounts for the highest incidence of acute liver failure, despite the availability of an antidote i.e. N-acetylcysteine. This calls for alternative strategies to manage APAP-induced liver injury (AILI). Therapeutic hypothermia has been explored in past studies for hepatoprotection, but these phenomenal reports lack clarification of its optimal window for application, and mechanistic effects in specific AILI. Hence, we conducted an in vitro study with transforming growth factor-α transgenic mouse hepatocytes cell line, TAMH, and human liver hepatocytes cell line, L-02, where cells were conditioned with deep (25°C) or moderate (32°C) hypothermia before, during or after APAP toxicity. Cell viability was evaluated as a hallmark of cytoprotection, along with cell death. Simultaneously, cold shock proteins (CSPs) and heat shock proteins expressions were monitored; key liver functions including drug-metabolizing ability and hepatic clearance were also investigated. Herein, we demonstrated significant hepatoprotection with 24-hour moderate hypothermic conditioning during AILI and this effect sustained for at least 24 hours of rewarming. Such liver preservation was associated with a CSP—RNA-binding motif protein 3 (RBM3) as its knockdown promptly abolished the cytoprotective effects of hypothermia. With mild and reversible liver perturbations, hypothermic therapy appears promising and its RBM3 involvement deserves future exploration.

Prenatal selective serotonin reuptake inhibitors and therapeutic hypothermia for suspected hypoxic ischemic encephalopathy

OBJECTIVE

To evaluate the association between prenatal selective serotonin reuptake inhibitor (SSRI) exposure and postnatal therapeutic hypothermia for suspected hypoxic ischemic encephalopathy.

STUDY DESIGN

Matched case-control study of singleton deliveries at a tertiary hospital from 2010 to 2016. Cases were infants treated with therapeutic hypothermia for suspected hypoxic ischemic encephalopathy. Controls were noncase infants, matched on gestational age, maternal age, obstetric provider group, and hospital shift.

RESULT

Prenatal SSRI exposure occurred in 18.4% of cases compared with 4.1% of controls (aOR: 5.9, 95% CI: 1.8-19.7). Among all cases, 36.8% had evidence of hypoxic ischemic encephalopathy on postnatal MRI. In addition, 28.6% of SSRI-exposed cases and 38.7% of SSRI-unexposed cases had MRI confirmation of hypoxic ischemic encephalopathy, respectively.

CONCLUSION

Future research to disentangle signs of SSRI exposure from true hypoxic ischemic encephalopathy may facilitate targeting therapeutic hypothermia stewardship toward infants more likely to benefit.

Pharmacotherapy for Seizures in Neonates with Hypoxic Ischemic Encephalopathy

Seizures are common in neonates with moderate and severe hypoxic ischemic encephalopathy (HIE) and are associated with worse outcomes, independent of HIE severity. In contrast to adults and older children, no new drugs have been licensed for treatment of neonatal seizures over the last 50 years, because of a lack of controlled clinical trials. Hence, many antiseizure medications licensed in older children and adults are used off-label for neonatal seizure, which is associated with potential risks of adverse effects during a period when the brain is particularly vulnerable. Phenobarbital is worldwide the first-line drug and is considered standard of care, although there is a limited evidence base for its efficacy. Second-line agents include phenytoin, benzodiazepines, levetiracetam, and lidocaine. These drugs are discussed in more detail along with two emerging drugs (bumetanide and topiramate). More safety, pharmacokinetic, and efficacy data are needed from well-designed clinical trials to develop safe and effective antiseizure regimes for the treatment of neonatal seizures in HIE.

Vision Assessments and Interventions for Infants 0-2 Years at High Risk for Cerebral Palsy: A Systematic Review

We performed a systematic review and evaluated the level of evidence of vision interventions and assessments for infants at high risk for or with a diagnosis of cerebral palsy from zero to two years of age. Articles were evaluated based on the level of methodologic quality, evidence, and clinical utilization. Thirty publications with vision assessments and five with vision interventions met criteria for inclusion. Assessments included standard care neuroimaging, electrophysiology, and neuro-ophthalmologic examination techniques that are utilized clinically with any preverbal or nonverbal pediatric patient. The overall level of evidence of interventions was strong for neuroprotective interventions such as caffeine and hypothermia but weak for surgery, visual training, or developmental programs. There are few evidence-based interventions and assessments that address cerebral/cortical visual impairment-related needs of infants and toddlers at high risk for or with cerebral palsy. Recommendation guidelines include the use of three types of standard care methodologies and two types of protective interventions.

A review of delivery room resuscitation in very low birth weight infants in a middle income country

BACKGROUND

Advanced levels of delivery room resuscitation in very low birth weight infants are reported to be associated with death and complications of prematurity. In resource limited settings, the need for delivery room resuscitation is often used as a reason to limit care in these infants.

METHODS

This was a review of delivery room resuscitation in very low birth weight infants born in a tertiary hospital in South Africa between 01 January 2013 and 30 June 2016. Outcomes included death and serious complications of prematurity. Advanced delivery room resuscitation was defined as the need for intubation, chest compressions or the administration of adrenaline.

RESULTS

A total of 1511 very low birth weight infants were included in the study. The majority (1332/1511 (88.2%) required oxygen in the delivery room. Face mask ventilation was needed in 45.2% (683/1511). Advanced delivery room resuscitation was only required in 10.6% (160/1511). More than half the infants who required advanced delivery room resuscitation died (89/160; 55.6%). Advanced delivery room resuscitation was required in significantly more infants <1000 grams at birth than those infants >1000 grams (83/539 (15.4%) vs 77/972 (7.9%) p < 0.001). Advanced delivery room resuscitation was significantly associated with a 5 minute Apgar score < 6 (OR 13.8 (95%CI 8.6-22.0), supplemental oxygen at day 28 (OR 2.2 (95% CI 1.4-3.9), metabolic acidosis (OR 2.3 (95% CI 1.1-4.8) and death (OR 1.9 95% CI 1.1-3.3). Other serious complications of prematurity were not associated with advanced delivery room resuscitation. Mortality was increased in infants with a low admission temperature (35.1 °C (SD 0.92) vs 36.1 °C (SD 1.4) (p < 0.001).

CONCLUSION

There was a high mortality rate associated with advanced delivery room resuscitation; however complications of prematurity were not increased in survivors..The need for advanced delivery room resuscitation alone should not be used as a predictor of poor outcome in very low birth weight infants. Survivors of advanced delivery room resuscitation should be afforded ventilatory support if required. Special care must be taken to avoid hypothermia in very low birth weight infants requiring resuscitation at birth.

RNA-binding protein RBM3 prevents NO-induced apoptosis in human neuroblastoma cells by modulating p38 signaling and miR-143

Nitric oxide (NO)-induced apoptosis in neurons is an important cause of neurodegenerative disease in humans. The cold-inducible protein RBM3 mediates the protective effects of cooling on apoptosis induced by various insults. However, whether RBM3 protects neural cells from NO-induced apoptosis is unclear. This study aimed to investigate the neuroprotective effect of RBM3 on NO-induced apoptosis in human SH-SY5Y neuroblastoma cells. Firstly, we demonstrated that mild hypothermia (32 °C) induces RBM3 expression and confers a potent neuroprotective effect on NO-induced apoptosis, which was substantially diminished when RBM3 was silenced by siRNA. Moreover, overexpression of RBM3 exhibited a strong protective effect against NO-induced apoptosis. Signaling pathway screening demonstrated that only p38 inhibition by RBM3 provided neuroprotective effect, although RBM3 overexpression could affect the activation of p38, JNK, ERK, and AKT signaling in response to NO stimuli. Notably, RBM3 overexpression also blocked the activation of p38 signaling induced by transforming growth factor-β1. Furthermore, both RBM3 overexpression and mild hypothermia abolished the induction of miR-143 by NO, which was shown to mediate the cytotoxicity of NO in a p38-dependent way. These findings suggest that RBM3 protects neuroblastoma cells from NO-induced apoptosis by suppressing p38 signaling, which mediates apoptosis through miR-143 induction.

[Stridor in neonates with hypoxic-ischaemic encephalopathy subject to selective cerebral or whole body hypothermia]

INTRODUCTION

Hypothermia treatment has improved the prognosis of asphyxiated neonates. Widely used, it has demonstrated to be safe without severe side effects. The aim of this article is to review the incidence of stridor amongst asphyxiated newborns treated with hypothermia in our unit.

METHODS

Retrospective chart review of our patients.

RESULTS

Stridor was presented in 7/75 (9.3%) of patients during hypothermia. Three received whole body hypothermia, 3 selective cerebral, and in one case both techniques were used. All cases required increased respiratory support.

CONCLUSIONS

Different mechanisms may be responsible for the appearance of stridor in patients with hypoxic-ischaemic encephalopathy (HIE). In our series the incidence of stridor was similar for the two hypothermia devices. To better understand these possible side effects of hypothermia, further prospective studies (which should include laryngoscopy) are needed.

Management of neonatal morbidities during hypothermia treatment

Although the primary goal of therapeutic hypothermia is to improve the neurodevelopmental outcome in asphyxiated infants, optimal management of the full range of multi-organ system complications typically presented by such infants during cooling treatment is necessary for improvement of the overall outcome. For this reason, adequate knowledge of how cooling affects all organ systems of asphyxiated infants with multi-organ hypoxic-ischemic injury is essential. Adequate diagnostic resources, readily available subspecialty consultant services and trained multidisciplinary staff to monitor and manage multi-organ system complications in asphyxiated infants during therapeutic cooling must be ensured during implementation of a cooling program. As therapeutic hypothermia is being used more widely, centers should consider participation in national or international benchmarking of outcomes and short-term adverse events during cooling to facilitate continuous quality improvement efforts.

Outcomes of hypoxic ischaemic encephalopathy treated with therapeutic hypothermia using cool gel packs - experience from Western Australia

Therapeutic hypothermia is the standard clinical practice for neonates with moderate to severe hypoxic ischaemic encephalopathy (HIE).

AIM

To describe the two year neurodevelopmental outcomes of neonates who were routinely cooled using cool gel packs for HIE in Western Australia.

METHODS

Retrospective study. Cases were identified from the neonatal databases. Information was collected from chart review.

RESULTS

65 infants received therapeutic hypothermia, of which 13 had mild, 35 moderate and 17 had severe HIE. There were no serious adverse effects attributable to cooling. All 13 infants with mild HIE survived, of whom developmental outcomes were available on nine; none had severe disability. Among 52 infants with moderate to severe HIE, there were nine deaths (17%) and developmental outcomes were available on 39; the incidence of severe disability was 23%. The risk of death or severe disability was 40% in infants with moderate to severe HIE. Physical growth was adequate at two years of age.

CONCLUSIONS

Neonates undergoing therapeutic hypothermia with cool gel packs had both good survival rates and long term neurodevelopmental outcomes and met international benchmarks.

Hypothermia for hypoxic-ischemic encephalopathy

Moderate to severe hypoxic-ischemic injury in newborn infants, manifested as encephalopathy immediately or within hours after birth, is associated with a high risk of either death or a lifetime with disability. In recent multicenter clinical trials, hypothermia initiated within the first 6 postnatal hours has emerged as a therapy that reduces the risk of death or impairment among infants with hypoxic-ischemic encephalopathy. Prior to hypothermia, no therapies directly targeting neonatal encephalopathy secondary to hypoxic-ischemic injury had convincing evidence of efficacy. Hypothermia therapy is now becoming increasingly available at tertiary centers. Despite the deserved enthusiasm for hypothermia, obstetric and neonatology caregivers, as well as society at large, must be reminded that in the clinical trials more than 40% of cooled infants died or survived with impairment. Although hypothermia is an evidence-based therapy, additional discoveries are needed to further improve outcome after HIE. In this article, we briefly present the epidemiology of neonatal encephalopathy due to hypoxic-ischemic injury, describe the rationale for the use of hypothermia therapy for hypoxic-ischemic encephalopathy, and present results of the clinical trials that have demonstrated the efficacy of hypothermia. We also present findings noted during and after these trials that will guide care and direct research for this devastating problem.

Hypothermia for perinatal brain hypoxia-ischemia in different resource settings: a systematic review

OBJECTIVE

To assess the effect of hypothermia on mortality of neonates with hypoxic-ischemic encephalopathy in different economic resources settings.

METHODS

We searched for randomized controlled trials on MEDLINE, Embase and other databases. Duplicate reviewers selected the studies and extracted data. We calculated meta-analyses of the relative risks (RR) and 95% confidence intervals (95% CI), and used meta-regression to evaluate the gross domestic product per capita influence on hypothermia efficacy.

RESULTS

Sixteen studies were included (n = 1889); eight were conducted in lower income countries (n = 662). Hypothermia significantly reduced mortality (RR = 0.77; 95% CI: 0.65-0.92). Meta-regression revealed that hypothermia efficacy does not increase as the gross domestic product per capita rises.

CONCLUSIONS

There is enough evidence to support hypothermia as the standard care for hypoxic-ischemic encephalopathy. Evidence from low-resource settings is limited, but hypothermia efficacy was not shown to be associated with better resources countries.

Optimizing therapeutic hypothermia for neonatal encephalopathy

OBJECTIVE

Therapeutic hypothermia (TH) for neonatal encephalopathy is becoming widely available in clinical practice. The goal of this collaborative was to create and implement an evidence-based standard-of-care approach to neonatal encephalopathy, deliver consistent care, and optimize outcomes.

METHODS

The quality improvement process identified and used the Model for Improvement as a framework for improvement efforts. This was a Vermont Oxford Network Collaborative focused on optimizing TH in the treatment of neonatal encephalopathy. By using an evidence-based approach, Potentially Better Practices were developed by the topic expert, modified by the collaborative, and implemented at each hospital. These included the following: timely identification of at-risk infants, coordination with referring hospitals to ensure TH was available within 6 hours after birth, staff education for both local and referring hospitals, nonsedated MRI, incorporating amplitude-integrated EEG into a TH protocol, and ensuring standard neurodevelopmental follow-up of infants. Each center used these practices to develop a matrix for implementation.

RESULTS

Local self-assessments directed the implementation and adaptation of the Potentially Better Practices at each center. Resources, based on common identified barriers, were developed and shared among the group.

CONCLUSIONS

The implementation of a TH program to improve the consistency of care for patients in NICUs is feasible using standard-quality improvement methodology. The successful introduction of new interventions such as TH to the NICU culture requires a collaborative multidisciplinary team, use of a systematic quality improvement process, and perseverance.

Cooling for newborns with hypoxic ischaemic encephalopathy

BACKGROUND

Newborn animal studies and pilot studies in humans suggest that mild hypothermia following peripartum hypoxia-ischaemia in newborn infants may reduce neurological sequelae without adverse effects.

OBJECTIVES

To determine the effect of therapeutic hypothermia in encephalopathic asphyxiated newborn infants on mortality, long-term neurodevelopmental disability and clinically important side effects.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group as outlined in The Cochrane Library (Issue 2, 2007). Randomised controlled trials evaluating therapeutic hypothermia in term and late preterm newborns with hypoxic ischaemic encephalopathy were identified by searching the Oxford Database of Perinatal Trials, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2007, Issue 2), MEDLINE (1966 to June 2007), previous reviews including cross-references, abstracts, conferences, symposia proceedings, expert informants and journal handsearching. We updated this search in May 2012.

SELECTION CRITERIA

We included randomised controlled trials comparing the use of therapeutic hypothermia with standard care in encephalopathic term or late preterm infants with evidence of peripartum asphyxia and without recognisable major congenital anomalies. The primary outcome measure was death or long-term major neurodevelopmental disability. Other outcomes included adverse effects of cooling and 'early' indicators of neurodevelopmental outcome.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected, assessed the quality of and extracted data from the included studies. Study authors were contacted for further information. Meta-analyses were performed using risk ratios (RR) and risk differences (RD) for dichotomous data, and weighted mean difference for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

We included 11 randomised controlled trials in this updated review, comprising 1505 term and late preterm infants with moderate/severe encephalopathy and evidence of intrapartum asphyxia. Therapeutic hypothermia resulted in a statistically significant and clinically important reduction in the combined outcome of mortality or major neurodevelopmental disability to 18 months of age (typical RR 0.75 (95% CI 0.68 to 0.83); typical RD -0.15, 95% CI -0.20 to -0.10); number needed to treat for an additional beneficial outcome (NNTB) 7 (95% CI 5 to 10) (8 studies, 1344 infants). Cooling also resulted in statistically significant reductions in mortality (typical RR 0.75 (95% CI 0.64 to 0.88), typical RD -0.09 (95% CI -0.13 to -0.04); NNTB 11 (95% CI 8 to 25) (11 studies, 1468 infants) and in neurodevelopmental disability in survivors (typical RR 0.77 (95% CI 0.63 to 0.94), typical RD -0.13 (95% CI -0.19 to -0.07); NNTB 8 (95% CI 5 to 14) (8 studies, 917 infants). Some adverse effects of hypothermia included an increase sinus bradycardia and a significant increase in thrombocytopenia.

AUTHORS' CONCLUSIONS

There is evidence from the 11 randomised controlled trials included in this systematic review (N = 1505 infants) that therapeutic hypothermia is beneficial in term and late preterm newborns with hypoxic ischaemic encephalopathy. Cooling reduces mortality without increasing major disability in survivors. The benefits of cooling on survival and neurodevelopment outweigh the short-term adverse effects. Hypothermia should be instituted in term and late preterm infants with moderate-to-severe hypoxic ischaemic encephalopathy if identified before six hours of age. Further trials to determine the appropriate techniques of cooling, including refinement of patient selection, duration of cooling and method of providing therapeutic hypothermia, will refine our understanding of this intervention.

Septicemia in a Neonate following Therapeutic Hypothermia: The Literature Review of Evidence

We report a term neonate with hypoxic ischemic encephalopathy who underwent a 72-hour therapeutic hypothermia. He developed unstable body temperature associated with coagulase negative staphylococcus septicemia 2 weeks later which was promptly treated with intravenous antibiotics and made a good recovery. PubMed (a service of the U.S. National Library of Medicine) was searched for the terms “therapeutic hypothermia” and “septicemia,” with limits activated (humans, English, age 0–18 years). There were only 6 randomized controlled trials, 1 non-randomized controlled trial, 1 retrospective cohort, and 1 case-control trial, which showed no definite evidence of increased risk of septicemia or neutrophil dysfunction in infants following hypothermia therapy.

Comparison of three hypothermic target temperatures for the treatment of hypoxic ischemia: mRNA level responses of eight genes in the piglet brain

Hypothermia can reduce neurodevelopmental disabilities in asphyxiated newborn infants. However, the optimal cooling temperature for neuroprotection is not well defined. We studied the effects of transient piglet brain hypoxic ischemia (HI) on transcriptional activity of eight genes and if mRNA level alterations could be counteracted by whole body cooling to 35, 33.5 or 30 °C. BDNF mRNA was globally upregulated by the insult, and none of the cooling temperatures counteracted this change. In contrast, MANF mRNA was downregulated, and these changes were modestly counteracted in different brain regions by hypothermic treatment at 33.5 °C, while 30 °C aggravated the MANF mRNA loss. MAP2 mRNA was markedly downregulated in all brain regions except striatum, and cooling to 33.5 °C modestly counteract this downregulation in the cortex cerebri. There was a tendency for GFAP mRNA levels in core, but not mantle regions to be downregulated and for these changes to be modestly counteracted by cooling to 33.5 or 35 °C. Cooling to 30 °C caused global GFAP mRNA decrease. HSP70 mRNA tended to become upregulated by HI and to be more pronounced in cortex and CA1 of hippocampus during cooling to 33.5 °C. We conclude that HI causes alterations of mRNA levels of many genes in superficial and deep piglet brain areas. Some of these changes may be beneficial, others detrimental, and lowering body temperature partly counteracts some, but not all changes. There may be general differences between core and mantle regions, as well as between the different cooling temperatures for protection. Comparing the three studied temperatures, cooling to 33.5 °C, appears to provide the best cooling temperature compromise.

Ethical issues in neonatal and pediatric clinical trials

Children have been identified as uniquely vulnerable clinical research subjects since the early 1970s. This article reviews the historical underpinnings of this designation, the current regulatory framework for pediatric and neonatal research, and common problems in pediatric research oversight. It also presents 3 areas of pediatric and neonatal research (genomic screening, healthy children donating stem cells, and therapeutic hypothermia for neonates with hypoxic-ischemic encephalopathy) that highlight contemporary challenges in pediatric research ethics, including balancing risk and benefit, informed consent and assent, and clinical equipoise.

Rescuing the neonatal brain from hypoxic injury with autologous cord blood

Brain injury resulting from perinatal hypoxic-ischemic encephalopathy (HIE) is a major cause of acute mortality in infants and chronic neurologic disability in surviving children. Recent multicenter clinical trials demonstrated the effectiveness of hypothermia initiated within the first 6 postnatal hours to reduce the risk of death or major neurological disabilities among neonates with HIE. However, in these trials, approximately 40% of cooled infants died or survived with significant impairments. Therefore, adjunct therapies are required to improve the outcome in neonates with HIE. Cord blood (CB) is a rich source of stem cells. Administration of human CB cells in animal models of HIE has generally resulted in improved outcomes and multiple mechanisms have been suggested including anti-inflammation, release of neurotrophic factors and stimulation of endogenous neurogenesis. Investigators at Duke are conducting studies of autologous CB infusion in neonates with HIE and in children with cerebral palsy. These pilot studies indicate no added risk from the regimens used, but results of ongoing placebo-controlled trials are needed to assess efficacy. Meanwhile, further investigations are warranted to determine the best strategies, that is, timing, dosing, route of delivery, choice of stem cells and ex vivo modulations, to attain long-term benefits of CB stem cell therapy.

Lessons learned during implementation of therapeutic hypothermia for neonatal hypoxic ischemic encephalopathy in a regional transport program in Ontario

BACKGROUND

Therapeutic hypothermia (TH) is the first intervention to consistently show improved neurological outcomes in neonates with hypoxic ischemic encephalopathy (HIE). Since the recent introduction of TH for HIE in many centres, reviews of practices during the implementation of TH in Canada have not been published.

OBJECTIVE

To determine if eligible neonates are being offered TH and to identify any barriers to the effective implementation of TH.

METHODS

A retrospective review of neonates referred to a regional tertiary centre at a gestational age of 35 weeks or more with HIE was conducted.

RESULTS

Among 41 neonates referred, 29 (71%) were eligible for TH; among eligible patients, five were moribund and excluded, and TH was initiated in 16 (67%) of the remaining 24. Reasons for not cooling in eight eligible patients included a delay in referral (n=5, median age at referral was 14 h) and a failure to recognize the severity of HIE (n=3). Among cooled patients, median times were the following: 116 min for age at referral; 80 min for time from referral to transport team arrival; and 358 min for age at initiation of cooling. Seven (44%) patients had cooling initiated after 6 h of age.

CONCLUSION

A significant proportion of eligible patients were not offered TH, and in many cooled patients, initiation of cooling was delayed beyond the recommended 6 h. For eligible patients to benefit from TH, it is imperative that all birthing centres be made aware that TH is now widely available as an important treatment option, but also that TH is a time-sensitive therapy requiring rapid identification and referral. In the region studied, for eligible patients, referring hospitals should initiate passive cooling before arrival of the transport team. Referring hospitals should be prepared to provide early, yet safe initiation of passive cooling by having the appropriate equipment, and having staff trained in the use and monitoring of rectal temperatures.

Prediction of neurodevelopmental outcome after hypoxic-ischemic encephalopathy treated with hypothermia by diffusion tensor imaging analyzed using tract-based spatial statistics

INTRODUCTION

Objective biomarkers are needed to assess neuroprotective therapies after perinatal hypoxic-ischemic encephalopathy (HIE). We tested the hypothesis that, in infants who underwent therapeutic hypothermia after perinatal HIE, neurodevelopmental performance was predicted by fractional anisotropy (FA) values in the white matter (WM) on early diffusion tensor imaging (DTI) as assessed by means of tract-based spatial statistics (TBSS).

METHODS

We studied 43 term infants with HIE. Developmental assessments were carried out at a median (range) age of 24 (12-28) mo.

RESULTS

As compared with infants with favorable outcomes, those with unfavorable outcomes had significantly lower FA values (P < 0.05) in the centrum semiovale, corpus callosum (CC), anterior and posterior limbs of the internal capsule, external capsules, fornix, cingulum, cerebral peduncles, optic radiations, and inferior longitudinal fasciculus. In a second analysis in 32 assessable infants, the Griffiths Mental Development Scales (Revised) (GMDS-R) showed a significant linear correlation (P < 0.05) between FA values and developmental quotient (DQ) and all its component subscale scores.

DISCUSSION

DTI analyzed by TBSS provides a qualified biomarker that can be used to assess the efficacy of additional neuroprotective therapies after HIE.

Extensive subcutaneous fat necrosis of the newborn associated with therapeutic hypothermia

Subcutaneous fat necrosis of the newborn is a form of panniculitis that most often occurs in full-term infants with predisposing risk factors. Three neonates with hypoxic ischemic encephalopathy were treated with therapeutic hypothermia and developed extensive subcutaneous fat necrosis. All three infants developed extensive subcutaneous fat necrosis, involving the back, scalp, and arms. Mild, asymptomatic hypercalcemia was noted in one infant in the weeks following the subcutaneous fat necrosis. Hypothermia as a risk factor for subcutaneous fat necrosis is reviewed. Clinicians should be aware of subcutaneous fat necrosis as a possible risk factor and complication associated with asphyxiated newborns who may undergo therapeutic hypothermia. Future studies for therapeutic hypothermia should evaluate neonates for the development of subcutaneous fat necrosis.

Laboratory markers of perinatal acidosis are poor predictors of neurodevelopmental impairment in very low birth weight infants

BACKGROUND

In asphyxiated term and near-term infants, therapeutic hypothermia increases survival without neurologic morbidity, and extending this new treatment to preterm infants is being debated.

AIMS

To investigate the association of low pH and base excess (BE) at birth or admission, as used as entry criteria in cooling trials, and evolving brain damage in preterm infants.

STUDY DESIGN AND MEASUREMENTS

Rates of death and neurodevelopmental impairment at 12 and 20 months corrected age were assessed in a cohort of 1137 preterm infants with a gestational age <35 weeks and birth weight <1500 g in relation to severe perinatal acidosis (umbilical artery pH≤7.0, pH at admission ≤7.0, BE at admission ≤-16 mmol/l, lowest BE during first 12 h of life ≤-16 mmol/l).

RESULTS

Umbilical artery pH was not linked to death or neurodevelopmental impairment. There was only weak predictive power of pH or BE at admission for death (positive predictive values [PPV] 0.36/0.30, receiver operator characteristics [ROC] areas 0.591/0.701), and lowest 12-h BE for death or neurodevelopmental impairment at 12 or 20 months (PPV 0.29/0.30/0.27, ROC 0.720/0.656/0.658).

CONCLUSION

In very preterm infants, there is little association between laboratory markers of severe perinatal acidosis and neurodevelopmental outcome at 12 or 20 months.

[Neuroprotection with hypothermia in the newborn with hypoxic-ischaemic encephalopathy. Standard guidelines for its clinical application]

Standardisation of hypothermia as a treatment for perinatal hypoxic-ischaemic encephalopathy is supported by current scientific evidence. The following document was prepared by the authors on request of the Spanish Society of Neonatology and is intended to be a guide for the proper implementation of this therapy. We discuss the difficulties that may arise when moving from the strict framework of clinical trials to clinical daily care: early recognition of clinical encephalopathy, inclusion and exclusion criteria, hypothermia during transport, type of hypothermia (selective head or systemic cooling) and side effects of therapy. The availability of hypothermia therapy has changed the prognosis of children with hypoxic-ischaemic encephalopathy and our choices of therapeutic support. In this sense, it is especially important to be aware of the changes in the predictive value of the neurological examination and the electroencephalographic recording in cooled infants. In order to improve neuroprotection with hypothermia we need earlier recognition of to recognise earlier the infants that may benefit from cooling. Biomarkers of brain injury could help us in the selection of these patients. Every single infant treated with hypothermia must be included in a follow up program in order to assess neurodevelopmental outcome.

Enhanced survival of skeletal muscle myoblasts in response to overexpression of cold shock protein RBM3

Cold-inducible RNA-binding protein (RBM3) is suggested to be involved in the regulation of skeletal muscle mass. Cell death pathways are implicated in the loss of muscle mass and therefore the role of RBM3 in muscle apoptosis in C(2)C(12) myoblasts was investigated in this study. RBM3 overexpression was induced by either cold shock (32°C exposure for 6 h) or transient transfection with a myc-tagged RBM3 expression vector. Cell death was induced by H(2)O(2) (1,000 μM) or staurosporine (StSp, 5 μM), and it was shown that cold shock and RBM3 transfection were associated with attenuation of morphological changes and an increase in cell viability compared with normal temperature or empty vector, respectively. No changes in proliferation were observed with either cold shock or RBM3 transfection. DNA fragmentation was not increased in response to H(2)O(2), and a cell permeability assay indicated that cell death in response to H(2)O(2) is more similar to necrosis than apoptosis. RBM3 overexpression reduced apoptosis and the collapse of the membrane potential in response to StSp. Moreover, the increase in caspase-3, -8, and -9 activities in response to StSp was returned to control levels with RBM3 overexpression. These results indicate that increased RBM3 expression decreases muscle cell necrosis as well as apoptosis and therefore RBM3 could potentially serve as an intervention for the loss of muscle cell viability during muscle atrophy and muscle diseases.

Current management of the infant who presents with neonatal encephalopathy

Neonatal encephalopathy after perinatal hypoxic-ischemic insult is a major contributor to global child mortality and morbidity. Brain injury in term infants in response to hypoxic-ischemic insult is a complex process evolving over hours to days, which provides a unique window of opportunity for neuroprotective treatment interventions. Advances in neuroimaging, brain monitoring techniques, and tissue biomarkers have improved the ability to diagnose, monitor, and care for newborn infants with neonatal encephalopathy as well as predict their outcome. However, challenges remain in early identification of infants at risk for neonatal encephalopathy, determination of timing and extent of hypoxic-ischemic brain injury, as well as optimal management and treatment duration. Therapeutic hypothermia is the most promising neuroprotective intervention to date for infants with moderate to severe neonatal encephalopathy after perinatal asphyxia and has currently been incorporated in many neonatal intensive care units in developed countries. However, only 1 in 6 babies with encephalopathy will benefit from hypothermia therapy; many infants still develop significant adverse outcomes. To enhance the outcome, specific diagnostic predictors are needed to identify patients likely to benefit from hypothermia treatment. Studies are needed to determine the efficacy of combined therapeutic strategies with hypothermia therapy to achieve maximal neuroprotective effect. This review focuses on important concepts in the pathophysiology, diagnosis, and management of infants with neonatal encephalopathy due to perinatal asphyxia, including an overview of recently introduced novel therapies.

The RNA-binding protein RBM3 is involved in hypothermia induced neuroprotection

Induced hypothermia is the only therapy with proven efficacy to reduce brain damage after perinatal asphyxia. While hypothermia down-regulates global protein synthesis and cell metabolism, low temperature induces a small subset of proteins that includes the RNA-binding protein RBM3 (RNA-binding motif protein 3), which has recently been implicated in cell survival. Here, immunohistochemistry of the developing postnatal murine brain revealed a spatio-temporal neuronal RBM3 expression pattern very similar to that of doublecortin, a marker of neuronal precursor cells. Mild hypothermia (32°C) profoundly promoted RBM3 expression and rescued neuronal cells from forced apoptosis as studied in primary neurons, PC12 cells, and cortical organotypic slice cultures. Blocking RBM3 expression in neuronal cells by specific siRNAs significantly diminished the neuroprotective effect of hypothermia while vector-driven RBM3 over-expression reduced cleavage of PARP, prevented internucleosomal DNA fragmentation, and LDH release also in the absence of hypothermia. Together, neuronal RBM3 up-regulation in response to hypothermia apparently accounts for a substantial proportion of hypothermia-induced neuroprotection.

Systemic complications and hypothermia

Cooling for neonatal hypoxic-ischemic encephalopathy is a novel and promising neuroprotective therapy that requires significant understanding of how cooling affects all organ systems and interventions used to treat systemic complications of cooling in an intensive care setting. As cooling is used more widely and has been newly introduced in neonatal units, continued surveillance of its use in clinical practice is mandatory. Units offering cooling should strongly consider joining a registry (e.g. the Vermont-Oxford Neonatal Encephalopathy Registry in the USA or the TOBY Register in the UK) that facilitates benchmarking of short-term adverse effects and long-term outcomes of cooling and that supports local quality improvement efforts.

Therapeutic hypothermia for newborn infants with hypoxic-ischaemic encephalopathy

Peripartum asphyxia complicated by moderate or severe hypoxic-ischaemic encephalopathy is a devastating global health issue. A therapeutic 'window of opportunity' exists after resuscitation of the asphyxiated newborn and before the delayed phase of neuronal loss. Animal studies demonstrated that neuronal injury following hypoxia-ischaemia can be prevented or reduced by a mild reduction in brain temperature. Human infant pilot studies confirmed feasibility, without major adverse effects. Randomised trials and systematic reviews comprising term infants with moderate or severe encephalopathy and peripartum asphyxia have established the neuroprotective benefit of therapeutic hypothermia. Hypothermia reduces mortality or major disability to 18 months of age, as well as cerebral palsy, and neuromotor and cognitive delay. Importantly, mortality is reduced without any increase in major neurodevelopmental disability in survivors, and with only minor adverse effects. The evidence supports therapeutic hypothermia when used within strict protocols in tertiary centres to improve the outcome for term and near-term newborns with moderate or severe hypoxic-ischaemic encephalopathy. Equally strict protocols in non-tertiary nurseries will enable earlier initiation of hypothermia under guidance of the regional neonatal intensive care unit and transport team.

Epidemiology of the cerebral palsies

Half of the most severe cases of cerebral palsy (CP) survive to adulthood, but because this longevity is relatively recent, there is no empirical experience of their life expectancy past middle age. The last 2 decades have seen significant developments in the management of persons with CP, involving specialist services from an increasing number of disciplines that require coordination to maximize their effectiveness. This article provides an overview of CP. The author discusses definitions of CP, its epidemiology, pathologies, and range of possible clinical descriptions, and briefly touches on management and prevention.

Treatment with docosahexaenoic acid after hypoxia-ischemia improves forepaw placing in a rat model of perinatal hypoxia-ischemia

OBJECTIVE

Docosahexaenoic acid (DHA) is a dietary fatty acid with neuroprotective properties. We hypothesized that DHA treatment after hypoxia-ischemia would improve function and reduce brain volume loss in a perinatal rat model.

STUDY DESIGN

Seven-day-old Wistar rat pups from 7 litters (n = 84) underwent right carotid ligation, followed by 8% O(2) for 90 minutes. Fifteen minutes after hypoxia-ischemia, pups were divided into 3 treatment groups (intraperitoneal injections of DHA 1, 2.5, or 5 mg/kg) and 2 control groups (25% albumin or saline). At 14 days, rats underwent vibrissae-stimulated forepaw placing testing, and bilateral regional volumes were calculated for cortex, striatum, hippocampus, and hemisphere.

RESULTS

Posthypoxia-ischemia treatment with DHA acid significantly improved vibrissae forepaw placing (complete responses: 8.5 ± 2 treatment vs 7.4 ± 2 controls; normal = 10; P = .032, t test). Postinjury DHA treatment did not attenuate brain volume loss in any region.

CONCLUSION

Posthypoxia-ischemia DHA treatment significantly improves functional outcome.

Ethics and hypothermia treatment

Hypothermia is the first effective neuroprotective intervention for newborns who are critically ill following a life-threatening asphyxial insult. It is not surprising that it has raised complex and controversial ethical dilemmas for investigators and clinicians. Given the history of iatrogenic disasters in neonatology, there has been an understandable reluctance to incorporate hypothermia into routine clinical practice until there is persuasive evidence from high quality randomised trials. This article reviews ethical issues that arose during the design of the original clinical trials, the implications of accumulating evidence of safety and efficacy, and the problems of ensuring informed parental participation in treatment decisions.

Hypothermia: a systematic review and meta-analysis of clinical trials

Hypothermia is a potential neuroprotective intervention to treat neonatal post-asphyxial (hypoxic-ischemic) encephalopathy (HIE). In this meta-analysis of 13 clinical trials published to date, therapeutic hypothermia was associated with a highly reproducible reduction in the risk of the combined outcome of mortality or moderate-to-severe neurodevelopmental disability in childhood. This improvement was internally consistent, as shown by significant reductions in the individual risk for death, moderate-to-severe neurodevelopmental disability, severe cerebral palsy, cognitive delay, and psychomotor delay. Patients in the hypothermia group had higher incidences of arrhythmia and thrombocytopenia; however, these were not clinically important. This analysis supports the use of hypothermia in reducing the risk of the mortality or moderate-to-severe neurodevelopmental disability in infants with moderate HIE.

Pentoxifylline in preterm neonates: a systematic review

Sepsis, necrotizing enterocolitis (NEC), and chronic lung disease (CLD) in preterm neonates are associated with significant mortality and morbidity, including long-term neurodevelopmental impairment and socioeconomic burden. Safe and effective drugs for the prevention and treatment of these conditions are urgently needed. Pentoxifylline, a synthetic theobromine derivative, is a non-steroidal immunomodulating agent with unique hemorrheologic effects which has been used in a range of infectious, vascular, and inflammatory conditions in adults and children. The unique properties of pentoxifylline explain its potential benefits in preterm neonates with sepsis, NEC, and CLD, conditions characterized by activation of the inflammatory cytokine cascade, free radical toxicity, and impaired microcirculation. Pentoxifylline has anti-inflammatory properties resulting from inhibition of erythrocyte phosphodiesterase. It lowers blood viscosity and improves microcirculation and tissue perfusion. As a phosphodiesterase inhibitor, pentoxifylline downregulates pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interferon-gamma. Methylxanthines, including caffeine, theophylline, and theobromine are relatively non-toxic drugs; of these, theobromine is the least toxic. Pentoxifylline-related significant adverse events are thus very rare. Unlike other methylxanthines, pentoxifylline does not have significant cardiac and bronchodilating effects at therapeutic doses. Although it is contraindicated in adults with recent cerebral hemorrhage due to its effect on platelets, red blood cells, and plasma fibrinogen levels, no significant adverse effects including thrombocytopenia and bleeding have been reported in critically ill preterm neonates with sepsis or NEC after treatment with pentoxifylline. Based on data from pilot randomized trials and observational studies, our systematic review suggests that pentoxifylline may reduce mortality and/or morbidity in preterm neonates with sepsis, NEC, and CLD. Results of experimental studies also indicate that pentoxifylline may potentially be beneficial in meconium aspiration syndrome and hypoxic ischemic encephalopathy. Given the substantial burden of sepsis, NEC, and CLD in high-risk preterm neonates, and the findings of this systematic review, pentoxifylline needs to be evaluated urgently as a preventative and therapeutic agent for these conditions in randomized controlled trials that can detect minimal clinically significant effect sizes. Further clinical and experimental studies are also necessary to evaluate whether pentoxifylline is safe and effective in meconium aspiration syndrome and hypoxic ischemic encephalopathy.

Systemic hypothermia after neonatal encephalopathy: outcomes of neo.nEURO.network RCT

OBJECTIVE

Mild hypothermia after perinatal hypoxic-ischemic encephalopathy (HIE) reduces neurologic sequelae without significant adverse effects, but studies are needed to determine the most-efficacious methods.

METHODS

In the neo.nEURO.network trial, term neonates with clinical and electrophysiological evidence of HIE were assigned randomly to either a control group, with a rectal temperature of 37°C (range: 36.5-37.5°C), or a hypothermia group, cooled and maintained at a rectal temperature of 33.5°C (range: 33-34°C) with a cooling blanket for 72 hours, followed by slow rewarming. All infants received morphine (0.1 mg/kg) every 4 hours or an equivalent dose of fentanyl. Neurodevelopmental outcomes were assessed at the age of 18 to 21 months. The primary outcome was death or severe disability.

RESULTS

A total of 129 newborn infants were enrolled, and 111 infants were evaluated at 18 to 21 months (53 in the hypothermia group and 58 in the normothermia group). The rates of death or severe disability were 51% in the hypothermia group and 83% in the normothermia group (P=.001; odds ratio: 0.21 [95% confidence interval [CI]: 0.09-0.54]; number needed to treat: 4 [95% CI: 3-9]). Hypothermia also had a statistically significant protective effect in the group with severe HIE (n=77; P=.005; odds ratio: 0.17 [95% CI: 0.05-0.57]). Rates of adverse events during the intervention were similar in the 2 groups except for fewer clinical seizures in the hypothermia group.

CONCLUSION

Systemic hypothermia in the neo.nEURO.network trial showed a strong neuroprotective effect and was effective in the severe HIE group.

Cost-effectiveness of therapeutic hypothermia to treat neonatal encephalopathy

OBJECTIVE

To estimate the cost-effectiveness (CE) of total body hypothermia plus intensive care versus intensive care alone to treat neonatal encephalopathy.

METHODS

Decision analytic modeling was used to synthesize mortality and morbidity data from three randomized controlled trials, the Total Body Hypothermia for Neonatal Encephalopathy Trial (TOBY), National Institute of Child Health and Human Development (NICHD), and CoolCap trials. Cost data inputs were informed by TOBY, the sole source of prospectively collected resource utilization data for encephalopathic infants. CE was expressed in terms of incremental cost per disability-free life year (DFLY) gained. Probabilistic sensitivity analysis was performed to generate CE acceptability curves (CEACs).

RESULTS

Cooling led to a cost increase of £3787 (95% confidence interval [CI]: -2516, 12,360) (€5115; 95% CI: -3398-16,694; US$5344; 95% CI: -3598, 26,356; using 2006 Organisation for Economic Co-operation and Development (OECD) purchasing power parities) and a DFLY gain of 0.19 (95%CI: 0.07-0.31) over the first 18 months after birth. The incremental cost per DFLY gained was £19,931 (€26,920; US$28,124). The baseline CEAC showed that if decision-makers are willing to pay £30,000 for an additional DFLY, there is a 69% probability that cooling is cost-effective. The probability of CE exceeded 99% at this threshold when the throughput of infants was increased to reflect the national incidence of neonatal encephalopathy or when the time horizon of the economic evaluation was extended to 18 years after birth.

CONCLUSIONS

The probability that cooling is a cost-effective treatment for neonatal encephalopathy is finely balanced over the first 18 months after birth but increases substantially when national incidence data or an extended time horizon are considered.

Therapeutic hypothermia and traumatic brain injury

PURPOSE OF REVIEW

Therapeutic hypothermia after traumatic brain injury (TBI)? For the last 10 years, no topic has been more popular and more controversial among neurointensivists. This article reviews the most current findings (experimental, clinical, adult and pediatric TBI), as well as the clinical management of therapeutic hypothermia.

RECENT FINDINGS

Despite ample experimental evidence, the clinical utility of therapeutic hypothermia has still to be conclusively demonstrated in terms of reduced mortality or improved functional recovery after TBI (even in pediatric TBI). Current findings support that hypothermia should be initiated as soon as possible, for at least 48 h duration, and that outcome is worse when barbiturates are part of ICU management. Currently, available cooling techniques, including prehospital cooling protocols, expand and improve clinical management of therapeutic hypothermia.

SUMMARY

Taking into consideration all results from clinical hypothermia TBI studies discussion has to be focused around the possibility that a better outcome could be achieved if protocols for therapeutic hypothermia are reviewed. It is possible that the negative effects of the cooling and the rewarming procedure currently overshadow the neuroprotective effects.

Evaluating a simple method of neuroprotective hypothermia for newborn infants

This study describes and evaluates a simple method of neuroprotective hypothermia for infants with hypoxic-ischaemic encephalopathy (HIE). Five term infants with HIE were cooled by applying soft, cold gel bags to the head. A radiant warmer, set to 34 degrees C, servo-controlled the temperature measured at a probe between the infant's back and the mattress. The infants' heads were shielded from the warmer. After 72 h, the infants were re-warmed by 0.2 degrees C per hour, by adjusting the radiant warmer. A rectal temperature of 34 degrees C was attained in a median time of 45 min. Mean rectal temperatures during cooling were 33.9 +/- 0.3 degrees C. There was good correlation between insulated back temperatures and deep rectal temperatures (r = 0.76). There were no major or irreversible adverse events during cooling. This method of cooling achieved rectal temperatures within the target range of 33-34 degrees C and re-warming was effective.

Body temperature effects on lung injury in ventilated preterm lambs

AIMS

Mechanical ventilation causes lung injury in premature infants. Hypothermia may protect against and hyperthermia may augment lung injury. We tested the effects of hypo- and hyperthermia on ventilation induced acute lung injury in preterm lambs.

METHODS

Twin sheep fetuses at 128 d GA (term 150 d) were surgically delivered and randomized to unventilated control (UVC), normothermia (38-39 degrees C) without lung injury (NTNI), or to 1 of 3 injurious ventilation groups: hypothermic (33-34 degrees C, LT), normothermic (38-39 degrees C, NT) or hyperthermic (40-41 degrees C, HT). NT, LT and HT groups had 15 min of injurious ventilation (PEEP 0 cmH(2)O, V(T) escalation to 15 mL/kg) following delivery and prior to surfactant. The animals were then gently ventilated (PEEP 5cmH(2)O, V(T) 7.5 mL/kg) for 2h 45 min. NTNI lambs received surfactant at birth prior to gentle ventilation. The lambs were then euthanized, and bronchoalveolar lavage (BAL) fluid and lung tissue were used to evaluate lung injury, inflammatory cell counts, inflammatory markers and cytokine mRNA.

RESULTS

Target temperatures were achieved by 15 min of age and maintained for 3h. All ventilated groups had increased BAL protein, lung inflammation and increased cytokine mRNA. HT animals developed acidosis, premature death, pneumothoraces, impaired lung function and increased inflammatory mRNA expression. LT animals remained clinically stable without pneumothoraces or death, had improved ventilatory efficiency and trended toward lower inflammatory mRNA expression than NT animals.

CONCLUSION

Hyperthermia exacerbated ventilator induced lung injury, while hypothermia may protect against lung injury in the preterm lamb.