Cooling for newborns with hypoxic ischaemic encephalopathy

Hypothermia protects human neurons

BACKGROUND AND AIMS

Hypothermia provides neuroprotection after cardiac arrest, hypoxic-ischemic encephalopathy, and in animal models of ischemic stroke. However, as drug development for stroke has been beset by translational failure, we sought additional evidence that hypothermia protects human neurons against ischemic injury.

METHODS

Human embryonic stem cells were cultured and differentiated to provide a source of neurons expressing β III tubulin, microtubule-associated protein 2, and the Neuronal Nuclei antigen. Oxygen deprivation, oxygen-glucose deprivation, and H2 O2 -induced oxidative stress were used to induce relevant injury.

RESULTS

Hypothermia to 33°C protected these human neurons against H2 O2 -induced oxidative stress reducing lactate dehydrogenase release and Terminal deoxynucleotidyl transferase dUTP nick end labeling-staining by 53% (P ≤ 0·0001; 95% confidence interval 34·8-71·04) and 42% (P ≤ 0·0001; 95% confidence interval 27·5-56·6), respectively, after 24 h in culture. Hypothermia provided similar protection against oxygen-glucose deprivation (42%, P ≤ 0·001, 95% confidence interval 18·3-71·3 and 26%, P ≤ 0·001; 95% confidence interval 12·4-52·2, respectively) but provided no protection against oxygen deprivation alone. Protection (21%) persisted against H2 O2 -induced oxidative stress even when hypothermia was initiated six-hours after onset of injury (P ≤ 0·05; 95% confidence interval 0·57-43·1).

CONCLUSION

We conclude that hypothermia protects stem cell-derived human neurons against insults relevant to stroke over a clinically relevant time frame. Protection against H2 O2 -induced injury and combined oxygen and glucose deprivation but not against oxygen deprivation alone suggests an interaction in which protection benefits from reduction in available glucose under some but not all circumstances.

Better Glasgow outcome score, cerebral perfusion pressure and focal brain oxygenation in severely traumatized brain following direct regional brain hypothermia therapy: A prospective randomized study

BACKGROUND

Induced hypothermia for treatment of traumatic brain injury is controversial. Since many pathways involved in the pathophysiology of secondary brain injury are temperature dependent, regional brain hypothermia is thought capable to mitigate those processes. The objectives of this study are to assess the therapeutic effects and complications of regional brain cooling in severe head injury with Glasgow coma scale (GCS) 6-7.

MATERIALS AND METHODS

A prospective randomized controlled pilot study involving patients with severe traumatic brain injury with GCS 6 and 7 who required decompressive craniectomy. Patients were randomized into two groups: Cooling and no cooling. For the cooling group, analysis was made by dividing the group into mild and deep cooling. Brain was cooled by irrigating the brain continuously with cold Hartmann solution for 24-48 h. Main outcome assessments were a dichotomized Glasgow outcome score (GOS) at 6 months posttrauma.

RESULTS

A total of 32 patients were recruited. The cooling-treated patients did better than no cooling. There were 63.2% of patients in cooling group attained good GOS at 6 months compared to only 15.4% in noncooling group (P = 0.007). Interestingly, the analysis at 6 months post-trauma disclosed mild-cooling-treated patients did better than no cooling (70% vs. 15.4% attained good GOS, P = 0.013) and apparently, the deep-cooling-treated patients failed to be better than either no cooling (P = 0.074) or mild cooling group (P = 0.650).

CONCLUSION

Data from this pilot study imply direct regional brain hypothermia appears safe, feasible and maybe beneficial in treating severely head-injured patients.

Transient receptor potential melastatin 8 channel inhibition potentiates the hypothermic response to transient receptor potential vanilloid 1 activation in the conscious mouse

OBJECTIVES

Mild decrease in core temperature (therapeutic hypothermia) provides lasting neuroprotection following cardiac arrest or cerebral ischemia. However, current methods for producing therapeutic hypothermia trigger a cold-defense response that must be countered by sedatives, muscle paralytics, and mechanical ventilation. We aimed to determine methods for producing hypothermia in the conscious mouse by targeting two transient receptor potential channels involved in thermoregulation, two transient receptor potential (TRP) channels involved in thermoregulation, TRP vanilloid 1 (TRPV1) and TRP melastatin 8 (TRPM8).

DESIGN

Controlled prospective animal study.

SETTING

Research laboratory at academic medical center.

SUBJECTS

Conscious unrestrained young and aged male mice.

INTERVENTIONS

Mice were treated with the TRPV1 agonist dihydrocapsaicin, a TRPM8 inhibitor ("compound 5"), or their combination and the effects on core temperature (Tcore) were measured by implanted thermocouples and wireless transponders.

MEASUREMENTS AND MAIN RESULTS

TRPV1 agonist dihydrocapsaicin produced a dose-dependent (2-4 mg/kg s.c.) drop in Tcore. A loading dose followed by continuous infusion of dihydrocapsaicin produced a rapid and prolonged (> 6 hr) drop of Tcore within the therapeutic range (32-34°C). The hypothermic effect of dihydrocapsaicin was augmented in aged mice and was not desensitized with repeated administration. TRPM8 inhibitor "compound 5" (20 mg/kg s.c.) augmented the drop in core temperature during cold exposure (8°C). When "compound 5" (30 mg/kg) was combined with dihydrocapsaicin (1.25-2.5 mg/kg), the drop in Tcore was amplified and prolonged.

CONCLUSIONS

Activating warm receptors (TRPV1) produced rapid and lasting hypothermia in young and old mice. Furthermore, hypothermia induced by TRPV1 agonists was potentiated and prolonged by simultaneous inhibition of TRPM8.

Outcomes in preterm infants

Preterm birth is defined as birth before 37 completed weeks gestation, and it is estimated that each day, across the world over 41,000 infants are born before this gestational age. The risk of adverse consequences declines with increasing gestational age. While this paper focuses on the consequences of preterm birth, the adverse consequences for infants born at 38 and 39 weeks gestation are also of a higher risk than those for infants born at 40 weeks gestation, with the neonatal mortality risk increasing again in infants born beyond the 42nd week of gestation.

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.

Adherence to hypothermia guidelines: a French multicenter study of fullterm neonates

AIM

The objective of this study was to describe the French practice of hypothermia treatment (HT) in full-term newborns with hypoxic-ischemic encephalopathy (HIE) and to analyze the deviations from the guidelines of the French Society of Neonatology.

MATERIALS AND METHODS

From May 2010 to March 2012 we recorded all cases of HIE treated by HT in a French national database. The population was divided into three groups, "optimal HT" (OHT), "late HT" (LHT) and "non-indicated" HT (NIHT), according to the guidelines.

RESULTS

Of the 311 newborns registered in the database and having HT, 65% were classified in the OHT group, 22% and 13% in the LHT and NIHT groups respectively. The severity of asphyxia and HIE were comparable between newborns with OHT and LHT, apart from EEG. HT was initiated at a mean time of 12 hours of life in the LHT group. An acute obstetrical event was more likely to be identified among newborns with LHT (46%), compared to OHT (34%) and NIHT (22%). There was a gradation in the rate of complications from the NIHT group (29%) to the LHT (38%) group and the OHT group (52%). Despite an insignificant difference in the rates of death or abnormal neurological examination at discharge, nearly 60% of newborns in the OHT group had an MRI showing abnormalities, compared to 44% and 49% in the LHT and NIHT groups respectively.

CONCLUSION

The conduct of the HT for HIE newborns is not consistent with French guidelines for 35% of newborns, 22% being explained by an excessive delay in the start of HT, 13% by the lack of adherence to the clinical indications. This first report illustrates the difficulties in implementing guidelines for HT and should argue for an optimization of perinatal care for HIE.

The membrane-active tri-block copolymer pluronic F-68 profoundly rescues rat hippocampal neurons from oxygen-glucose deprivation-induced death through early inhibition of apoptosis

Pluronic F-68, an 80% hydrophilic member of the Pluronic family of polyethylene-polypropylene-polyethylene tri-block copolymers, protects non-neuronal cells from traumatic injuries and rescues hippocampal neurons from excitotoxic and oxidative insults. F-68 interacts directly with lipid membranes and restores membrane function after direct membrane damage. Here, we demonstrate the efficacy of Pluronic F-68 in rescuing rat hippocampal neurons from apoptosis after oxygen-glucose deprivation (OGD). OGD progressively decreased neuronal survival over 48 h in a severity-dependent manner, the majority of cell death occurring after 12 h after OGD. Administration of F-68 for 48 h after OGD rescued neurons from death in a dose-dependent manner. At its optimal concentration (30 μm), F-68 rescued all neurons that would have died after the first hour after OGD. This level of rescue persisted when F-68 administration was delayed 12 h after OGD. F-68 did not alter electrophysiological parameters controlling excitability, NMDA receptor-activated currents, or NMDA-induced increases in cytosolic calcium concentrations. However, F-68 treatment prevented phosphatidylserine externalization, caspase activation, loss of mitochondrial membrane potential, and BAX translocation to mitochondria, indicating that F-68 alters apoptotic mechanisms early in the intrinsic pathway of apoptosis. The profound neuronal rescue provided by F-68 after OGD and the high level of efficacy with delayed administration indicate that Pluronic copolymers may provide a novel, membrane-targeted approach to rescuing neurons after brain ischemia. The ability of membrane-active agents to block apoptosis suggests that membranes or their lipid components play prominent roles in injury-induced apoptosis.

Evolution of pattern of injury and quantitative MRI on days 1 and 3 in term newborns with hypoxic-ischemic encephalopathy

BACKGROUND

Brain injury in term neonatal hypoxic-ischemic encephalopathy (HIE) emerges on magnetic resonance imaging (MRI) by day 3. This study aimed to address the relationship of MRI, diffusion tensor imaging (DTI), and MR spectroscopic imaging (MRSI) findings on days 1 and 3 in a prospective cohort of term newborns with HIE.

METHODS

A total of 24 term newborns with HIE were prospectively studied with MRI on days 1 and 3; 19 were imaged with DTI and MRSI on days 1 and 3. MRI was assessed using validated scores. The relationship between MRI, DTI, and MRSI values on days 1 and 3 was determined using linear regression for repeated measures.

RESULTS

Conventional MRI showed a complex variation of findings from day 1 to 3. In gray matter, mean diffusivity (Dav) and metabolite ratios measured on day 1 were predictive of values on day 3 (all P ≤ 0.04). In white matter, Dav, fractional anisotropy (FA), and N-acetylaspartate (NAA)/choline on days 1 and 3 were strongly related (all P ≤ 0.003). Hypothermia appeared to attenuate the severity and progression of brain injury in the six treated newborns.

CONCLUSION

In term newborns with HIE, quantitative MR values on days 1 and 3 are strongly associated, providing an objective measure of injury before qualitative images.

Quantitative in vivo detection of brain cell death after hypoxia ischemia using the lipid peak at 1.3 ppm of proton magnetic resonance spectroscopy in neonatal rats

This study was performed to determine the accuracy of proton magnetic spectroscopy ((1)H-MRS) lipid peak as a noninvasive tool for quantitative in vivo detection of brain cell death. Seven day-old Sprague Dawley rats were subjected to 8% oxygen following a unilateral carotid artery ligation. For treatment, cycloheximide was given immediately after hypoxic ischemia (HI). Lipid peak was measured using (1)H-MRS at 24 hr after HI, and then brains were harvested for fluorocytometric analyses with annexin V/propidium iodide (PI) and fluorescent probe JC-1, and for adenosine-5'-triphosphate (ATP) and lactate. Increased lipid peak at 1.3 ppm measured with (1)H-MRS, apoptotic and necrotic cells, and loss of mitochondrial membrane potential (ΔΨ) at 24 hr after HI were significantly improved with cycloheximide treatment. Significantly reduced brain ATP and increased lactate levels observed at 24 hr after HI showed a tendency to improve without statistical significance with cycloheximide treatment. Lipid peak at 1.3 ppm showed significant positive correlation with both apoptotic and necrotic cells and loss of ΔΨ, and negative correlation with normal live cells. Lipid peak at 1.3 ppm measured by (1)H-MRS might be a sensitive and reliable diagnostic tool for quantitative in vivo detection of brain cell death after HI.

Brain resuscitation in the drowning victim

Drowning is a leading cause of accidental death. Survivors may sustain severe neurologic morbidity. There is negligible research specific to brain injury in drowning making current clinical management non-specific to this disorder. This review represents an evidence-based consensus effort to provide recommendations for management and investigation of the drowning victim. Epidemiology, brain-oriented prehospital and intensive care, therapeutic hypothermia, neuroimaging/monitoring, biomarkers, and neuroresuscitative pharmacology are addressed. When cardiac arrest is present, chest compressions with rescue breathing are recommended due to the asphyxial insult. In the comatose patient with restoration of spontaneous circulation, hypoxemia and hyperoxemia should be avoided, hyperthermia treated, and induced hypothermia (32-34 °C) considered. Arterial hypotension/hypertension should be recognized and treated. Prevent hypoglycemia and treat hyperglycemia. Treat clinical seizures and consider treating non-convulsive status epilepticus. Serial neurologic examinations should be provided. Brain imaging and serial biomarker measurement may aid prognostication. Continuous electroencephalography and N20 somatosensory evoked potential monitoring may be considered. Serial biomarker measurement (e.g., neuron specific enolase) may aid prognostication. There is insufficient evidence to recommend use of any specific brain-oriented neuroresuscitative pharmacologic therapy other than that required to restore and maintain normal physiology. Following initial stabilization, victims should be transferred to centers with expertise in age-specific post-resuscitation neurocritical care. Care should be documented, reviewed, and quality improvement assessment performed. Preclinical research should focus on models of asphyxial cardiac arrest. Clinical research should focus on improved cardiopulmonary resuscitation, re-oxygenation/reperfusion strategies, therapeutic hypothermia, neuroprotection, neurorehabilitation, and consideration of drowning in advances made in treatment of other central nervous system disorders.

Near-infrared spectroscopy versus magnetic resonance imaging to study brain perfusion in newborns with hypoxic-ischemic encephalopathy treated with hypothermia

BACKGROUND

The measurement of brain perfusion may provide valuable information for assessment and treatment of newborns with hypoxic-ischemic encephalopathy (HIE). While arterial spin labeled perfusion (ASL) magnetic resonance imaging (MRI) provides noninvasive and direct measurements of regional cerebral blood flow (CBF) values, it is logistically challenging to obtain. Near-infrared spectroscopy (NIRS) might be an alternative, as it permits noninvasive and continuous monitoring of cerebral hemodynamics and oxygenation at the bedside.

OBJECTIVE

The purpose of this study is to determine the correlation between measurements of brain perfusion by NIRS and by MRI in term newborns with HIE treated with hypothermia.

DESIGN/METHODS

In this prospective cohort study, ASL-MRI and NIRS performed during hypothermia were used to assess brain perfusion in these newborns. Regional cerebral blood flow (CBF) values, measured from 1-2 MRI scans for each patient, were compared to mixed venous saturation values (SctO2) recorded by NIRS just before and after each MRI. Analysis included groupings into moderate versus severe HIE based on their initial background pattern of amplitude-integrated electroencephalogram.

RESULTS

Twelve concomitant recordings were obtained of seven neonates. Strong correlation was found between SctO2 and CBF in asphyxiated newborns with severe HIE (r=0.88; p value=0.0085). Moreover, newborns with severe HIE had lower CBF (likely lower oxygen supply) and extracted less oxygen (likely lower oxygen demand or utilization) when comparing SctO2 and CBF to those with moderate HIE.

CONCLUSIONS

NIRS is an effective bedside tool to monitor and understand brain perfusion changes in term asphyxiated newborns, which in conjunction with precise measurements of CBF obtained by MRI at particular times, may help tailor neuroprotective strategies in term newborns with HIE.

Heart Rate and Arterial Pressure Changes during Whole-Body Deep Hypothermia

Whole-body deep hypothermia (DH) could be a new therapeutic strategy for asphyxiated newborn. This retrospective study describes how DH modified the heart rate and arterial blood pressure if compared to mild hypothermia (MH). Fourteen in DH and 17 in MH were cooled within the first six hours of life and for the following 72 hours. Hypothermia criteria were gestational age ≥36 weeks; birth weight ≥1800 g; clinical signs of moderate/severe hypoxic-ischemic encephalopathy. Rewarming was obtained in the following 6-12 hours (0.5°C/h) after cooling. Heart rates were the same between the two groups; there was statistically significant difference at the beginning of hypothermia and during rewarming. Three babies in the DH group and 2 in the MH group showed HR < 80 bpm and QTc > 520 ms. Infant submitted to deep hypothermia had not bradycardia or Qtc elongation before cooling and after rewarming. Blood pressure was significantly lower in DH compared to MH during the cooling, and peculiar was the hypotension during rewarming in DH group. Conclusion. The deeper hypothermia is a safe and feasible, only if it is performed by a well-trained team. DH should only be associated with a clinical trial and prospective randomized trials to validate its use.

Predictors of neurological outcome in cooled neonates

BACKGROUND

We define clinical predictors of neurological outcome in neonates with hypoxic-ischemic encephalopathy undergoing hypothermia therapy.

METHODS

Twenty-one neonates who underwent selective head cooling between 2004 and 2010 and were followed neurologically for ≥ 24 months were investigated retrospectively. Patients were divided according to the neurological outcome at 2 years of age into group A (n = 11), patients with normal neurological function, and group B (n = 10), patients with neurological disabilities (n = 9) or those who died (n = 1). Predictors were determined by χ(2) and Mann-Whitney U-tests, anova, Spearman rank correlations and receiver-operator curves.

RESULTS

Group B showed higher average blood lactate levels during the first day, particularly at 24 h of life; lower day-3 cerebral blood flow resistance index; higher maximum dobutamine dose used; higher rate of thiamylal sodium used; more severe background electroencephalogram suppression during the first week (group A: 11/11 cases ≤ grade 3; group B: 7/9 cases at grade 4-5) and higher rate of cerebral lesions on magnetic resonance imaging in the second week (group A: 1/11 case; group B: 9/10 cases) than group A. The most useful predictor of poor prognosis was cerebral parenchymal lesions on magnetic resonance imaging with 90%, 90% and 90% of sensitivity, specificity and accuracy, followed by week-1 background electroencephalogram ≥ grade 4 with 70%, 100% and 85% and day-3 cerebral blood flow resistance index < 0.46 with 71%, 88% and 80%, respectively.

CONCLUSIONS

Prediction of post-cooling neurological outcome could be improved substantially by evaluating multiple factors.

Evaluation of hypercoagulability using soluble fibrin monomer complex in sick newborns

BACKGROUND

Soluble fibrin monomer complex (SFMC) and fibrin monomer (FM) are well known as markers for hypercoagulability, but such measurements have not been investigated in detail for the neonate. To identify the presence of a hypercoagulable state in sick newborns, the behavior of SFMC with special reference to those of other coagulation tests, and the relationships with other parameters of blood coagulation as well as lactate, which is considered to be the gold standard for assessing tissue hypoxia, were studied.

METHODS

Records of 216 sick newborns, who had undergone blood coagulation tests, were retrospectively studied based on their medical records.

RESULTS

SFMC had a significant correlation with d-dimer in infants with birthweight <1500 g, but no correlation was observed with prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, anti-thrombin or platelet count. In contrast, in infants with birthweight ≥ 1500 g, SFMC was correlated with PT, APTT, fibrinogen, and d-dimer, but no correlation was observed with anti-thrombin or platelet count. In addition, SFMC was significantly higher in the high lactate group (lactate ≥ 4 mmol/L), compared with the low lactate group (<4 mmol/L).

CONCLUSION

Measurement of blood SFMC is useful to monitor hypercoagulable state in sick newborns with hypoxia.

Subcutaneous fat necrosis after selective head cooling in an infant

Hypoxic-ischemic encephalopathy in neonates causes irreversible damage to tissue and organs and results in multiple organ failure and poor outcome. Therapeutic hypothermia is the most effective therapy in neonates with hypoxic-ischemic encephalopathy. We report here a case of subcutaneous fat necrosis (SCFN) after therapeutic hypothermia by selective head cooling. Selective head cooling was provided for 72 h after birth. SCFN developed on the patient's cheeks and back at the age of 21 days. Thus, SCFN may be caused by selective head cooling, similarly to whole-body cooling.

Hypothermia for neuroprotection in children after cardiopulmonary arrest

BACKGROUND

Cardiopulmonary arrest in paediatric patients often results in death or survival with severe brain injury. Therapeutic hypothermia, lowering of the core body temperature to 32°C to 34°C, may reduce injury to the brain in the period after the circulation has been restored. This therapy has been effective in neonates with hypoxic ischaemic encephalopathy and adults after witnessed ventricular fibrillation cardiopulmonary arrest. The effect of therapeutic hypothermia after cardiopulmonary arrest in paediatric patients is unknown.

OBJECTIVES

To assess the clinical effectiveness of therapeutic hypothermia after paediatric cardiopulmonary arrest.

SEARCH METHODS

We searched the Cochrane Anaesthesia Review Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 11); Ovid MEDLINE (1966 to December 2011); Ovid EMBASE (1980 to December 2011); Ovid CINAHL (1982 to December 2011); Ovid BIOSIS (1923 to December 2011); and Web of Science (1945 to December 2011). We searched the trials registry databases for ongoing trials. We also contacted international experts in therapeutic hypothermia and paediatric critical care to locate further published and unpublished studies.

SELECTION CRITERIA

We planned to include randomized and quasi-randomized controlled trials comparing therapeutic hypothermia with normothermia or standard care in children, aged 24 hours to 18 years, after paediatric cardiopulmonary arrest.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed articles for inclusion.

MAIN RESULTS

We found no studies that satisfied the inclusion criteria. We found four on-going randomized controlled trials which may be available for analysis in the future. We excluded 18 non-randomized studies. Of these 18 non-randomized studies, three compared therapeutic hypothermia with standard therapy and demonstrated no difference in mortality or the proportion of children with a good neurological outcome; a narrative report was presented.

AUTHORS' CONCLUSIONS

Based on this review, we are unable to make any recommendations for clinical practice. Randomized controlled trials are needed and the results of on-going trials will be assessed when available.

Transplantation of Human Adipose Tissue-Derived Mesenchymal Stem Cells Restores the Neurobehavioral Disorders of Rats With Neonatal Hypoxic-Ischemic Encephalopathy

Improving the effects of human adipose tissue-derived mesenchymal stem cells (ASCs) on the demyelination and neurobehavioral function was investigated in an experimental model of neonatal hypoxic-ischemic encephalopathy (HIE). Seven-day-old male rats were subjected to hypoxia-ischemia-lipopolysaccharide and intracerebroventricularly transplanted with human ASCs (4 × 10(5) cells/rat) once at postnatal day 10 (PND10) or repeatedly at PND10, 17, 27, and 37. Neurobehavioral abnormalities (at PND20, 30, and 40) and cognitive functions (at PND41-44) were evaluated using multiple test systems. Human ASCs recovered the using ratio of forelimb contralateral to the injured brain, improved locomotor activity, and restored rota-rod performance of HIE animals, in addition to showing a marked improvement of cognitive functions. It was confirmed that transplanted human ASCs migrated to injured areas and differentiated into oligodendrocytes expressing myelin basic protein (MBP). Moreover, transplanted ASCs restored production of growth and neurotrophic factors and expression of decreased inflammatory cytokines, leading to attenuation of host MBP loss. The results indicate that transplanted ASCs restored neurobehavioral functions by producing MBP as well as by preserving host myelins, which might be mediated by ASCs' anti-inflammatory activity and release of growth and neurotrophic factors.

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.

Acupuncture for hypoxic ischemic encephalopathy in neonates

BACKGROUND

Hypoxic ischemic encephalopathy (HIE) in the neonate is associated with high mortality and morbidity. Effective treatment options are limited and therefore alternative therapies such as acupuncture are increasingly used.

OBJECTIVES

We sought to determine the efficacy and safety of acupuncture on mortality and morbidity in neonates with HIE.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), Cochrane Neonatal Specialized Register, MEDLINE, AMED, EMBASE, PubMed, CINAHL, PsycINFO, WHO International Clinical Trials Registry Platform, and various Chinese medical databases in November 2012.

SELECTION CRITERIA

We planned to include randomized or quasi-randomized controlled trials comparing needle acupuncture to a control group that used no treatment, placebo or sham treatment in neonates (less than 28 days old) with HIE. Co-interventions were allowed as long as both the intervention and the control group received the same co-interventions. We excluded trials that evaluated therapy that did not involve penetration of the skin with a needle or trials that compared different forms of acupuncture only.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed trials for inclusion. If trials were identified, the review authors planned to assess trial quality and extract data independently. We planned to use the risk ratio (RR), risk difference (RD), and number needed to benefit (NNTB) or harm (NNTH) with 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) with 95% CI for continuous outcomes.

MAIN RESULTS

No trial satisfied our predefined inclusion criteria. Existing trials only evaluated acupuncture in older infants who survived HIE. There are currently no randomized controlled trials evaluating the efficacy of acupuncture for treatment of HIE in neonates. The safety of acupuncture for HIE in neonates is unknown.

AUTHORS' CONCLUSIONS

The rationale for acupuncture in neonates with HIE is unclear and the evidence from randomized controlled trial is lacking. Therefore, we do not recommend acupuncture for the treatment of HIE in neonates. High quality randomized controlled trials on acupuncture for HIE in neonates are needed.

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.

Cerebral inflammation and mobilization of the peripheral immune system following global hypoxia-ischemia in preterm sheep

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is one of the most important causes of brain injury in preterm infants. Preterm HIE is predominantly caused by global hypoxia-ischemia (HI). In contrast, focal ischemia is most common in the adult brain and known to result in cerebral inflammation and activation of the peripheral immune system. These inflammatory responses are considered to play an important role in the adverse outcomes following brain ischemia. In this study, we hypothesize that cerebral and peripheral immune activation is also involved in preterm brain injury after global HI.

METHODS

Preterm instrumented fetal sheep were exposed to 25 minutes of umbilical cord occlusion (UCO) (n = 8) at 0.7 gestation. Sham-treated animals (n = 8) were used as a control group. Brain sections were stained for ionized calcium binding adaptor molecule 1 (IBA-1) to investigate microglial proliferation and activation. The peripheral immune system was studied by assessment of circulating white blood cell counts, cellular changes of the spleen and influx of peripheral immune cells (MPO-positive neutrophils) into the brain. Pre-oligodendrocytes (preOLs) and myelin basic protein (MBP) were detected to determine white matter injury. Electro-encephalography (EEG) was recorded to assess functional impairment by interburst interval (IBI) length analysis.

RESULTS

Global HI resulted in profound activation and proliferation of microglia in the hippocampus, periventricular and subcortical white matter. In addition, non-preferential mobilization of white blood cells into the circulation was observed within 1 day after global HI and a significant influx of neutrophils into the brain was detected 7 days after the global HI insult. Furthermore, global HI resulted in marked involution of the spleen, which could not be explained by increased splenic apoptosis. In concordance with cerebral inflammation, global HI induced severe brain atrophy, region-specific preOL vulnerability, hypomyelination and persistent suppressed brain function.

CONCLUSIONS

Our data provided evidence that global HI in preterm ovine fetuses resulted in profound cerebral inflammation and mobilization of the peripheral innate immune system. These inflammatory responses were paralleled by marked injury and functional loss of the preterm brain. Further understanding of the interplay between preterm brain inflammation and activation of the peripheral immune system following global HI will contribute to the development of future therapeutic interventions in preterm HIE.

Cost-effective therapeutic hypothermia treatment device for hypoxic ischemic encephalopathy

Despite recent advances in neonatal care and monitoring, asphyxia globally accounts for 23% of the 4 million annual deaths of newborns, and leads to hypoxic-ischemic encephalopathy (HIE). Occurring in five of 1000 live-born infants globally and even more in developing countries, HIE is a serious problem that causes death in 25%–50% of affected neonates and neurological disability to at least 25% of survivors. In order to prevent the damage caused by HIE, our invention provides an effective whole-body cooling of the neonates by utilizing evaporation and an endothermic reaction. Our device is composed of basic electronics, clay pots, sand, and urea-based instant cold pack powder. A larger clay pot, lined with nearly 5 cm of sand, contains a smaller pot, where the neonate will be placed for therapeutic treatment. When the sand is mixed with instant cold pack urea powder and wetted with water, the device can extract heat from inside to outside and maintain the inner pot at 17°C for more than 24 hours with monitoring by LED lights and thermistors. Using a piglet model, we confirmed that our device fits the specific parameters of therapeutic hypothermia, lowering the body temperature to 33.5°C with a 1°C margin of error. After the therapeutic hypothermia treatment, warming is regulated by adjusting the amount of water added and the location of baby inside the device. Our invention uniquely limits the amount of electricity required to power and operate the device compared with current expensive and high-tech devices available in the United States. Our device costs a maximum of 40 dollars and is simple enough to be used in neonatal intensive care units in developing countries.

Hypothermia for newborns with hypoxic ischemic encephalopathy

Hypoxic ischemic encephalopathy (HIE) remains a significant cause of mortality and long-term disability in late preterm and term infants. Mild therapeutic hypothermia to a rectal temperature of 34±0.5°C initiated as soon as possible within the first 6 h of life decreases mortality and severe long-term neurodevelopmental disabilities in infants with moderate HIE who are ≥36 weeks' gestational age. There are minimal side effects, and the incidence of disability in survivors is not increased. Infants with severe encephalopathy are less likely to benefit from treatment. Cooling may be achieved by either total body or selective head cooling. As cooling is now considered a standard of care, infants ≥36 weeks' gestational age who are depressed at birth should be assessed to determine whether they meet the criteria for cooling. There is currently no evidence that therapeutic hypothermia offers any benefit to infants <36 weeks' gestational age.

Time is brain: starting therapeutic hypothermia within three hours after birth improves motor outcome in asphyxiated newborns

OBJECTIVE

Therapeutic hypothermia (HT) is the standard treatment for newborns after perinatal asphyxia. Preclinical studies report that HT is more effective when started early.

METHODS

Eighty cooled newborns were analyzed and grouped according to when cooling was started after birth: early (≤180 min) or late (>181 min). For survivors we analyzed whether starting cooling early was associated with a better psychomotor or mental developmental index (PDI or MDI, Bayley Scales of Infant Development II) than late cooling.

RESULTS

Forty-three newborns started cooling early and 37 started late. There was no significant difference in the severity markers of perinatal asphyxia between the groups; however, nonsurvivors (n = 15) suffered more severe asphyxia and had significantly lower centiles for weight (BWC; p = 0.009). Of the 65 infants that survived, 35 were cooled early and 30 were cooled late. There was no difference in time to start cooling between those who survived and those who did not. For survivors, median PDI (IQR) was significantly higher when cooled early [90 (77-99)] compared to being cooled later [78 (70-90); p = 0.033]. There was no increase in cardiovascular adverse effects in those cooled early. There was no significant difference in MDI between early and late cooling [93 (77-103) vs. 89 (76-106), p = 0.594].

CONCLUSION

Starting cooling before 3 h of age in surviving asphyxiated newborns is safe and significantly improves motor outcome. Cooling should be initiated as soon as possible after birth in eligible infants.

Pathophysiology of cerebral palsy

Cerebral palsy (CP), defined as a group of nonprogressive disorders of movement and posture, is the most common cause of severe neurodisability in children. Understanding its physiopathology is crucial to developing some protective strategies. Interruption of oxygen supply to the fetus or brain asphyxia was classically considered to be the main causal factor explaining later CP. However several ante-, peri-, and postnatal factors could be involved in the origins of CP syndromes. Congenital malformations are rarely identified. CP is most often the result of environmental factors, which might interact with genetic vulnerabilities, and could be severe enough to cause the destructive injuries visible with standard imaging (i.e., ultrasonographic study or MRI), predominantly in the white matter in preterm infants and in the gray matter and the brainstem nuclei in full-term newborns. Moreover they act on an immature brain and could alter the remarkable series of developmental events. Biochemical key factors originating in cell death or cell process loss, observed in hypoxic-ischemic as well as inflammatory conditions, are excessive production of proinflammatory cytokines, oxidative stress, maternal growth factor deprivation, extracellular matrix modifications, and excessive release of glutamate, triggering the excitotoxic cascade. Only two strategies have succeeded in decreasing CP in 2-year-old children: hypothermia in full-term newborns with moderate neonatal encephalopathy and administration of magnesium sulfate to mothers in preterm labor.

Effects of combination therapy using hypothermia and erythropoietin in a rat model of neonatal hypoxia-ischemia

BACKGROUND

Hypoxic-ischemic (HI) injury to the developing brain remains a major cause of morbidity. Hypothermia is effective but does not provide complete neuroprotection, prompting a search for adjunctive therapies. Erythropoietin (Epo) has been shown to be beneficial in several models of neonatal HI. This study examines combination hypothermia and treatment with erythropoietin in neonatal rat HI.

METHODS

Rats at postnatal day 7 were subjected to HI (Vannucci model) and randomized into four groups: no treatment, hypothermia alone, Epo alone, or hypothermia and Epo. Epo (1,000 U/kg) was administered in three doses: immediately following HI, and 24 h and 1 wk later. Hypothermia consisted of whole-body cooling for 8 h. At 2 and 6 wk following HI, sensorimotor function was assessed via cylinder-rearing test and brain damage by injury scoring. Sham-treated animals not subjected to HI were also studied.

RESULTS

Differences between experimental groups, except for Epo treatment on histopathological outcome in males, were not statistically significant, and combined therapy had no adverse effects.

CONCLUSION

No significant benefit was observed from treatment with either hypothermia or combination therapy. Future studies may require older animals, a wider range of functional assays, and postinsult assessment of injury severity to identify only moderately damaged animals for targeted therapy.

Introduction of hypothermia for neonates with perinatal asphyxia in the Netherlands and Flanders

BACKGROUND

Therapeutic hypothermia was introduced in the Netherlands and Flanders, Belgium, in 2008. Since then, an increasing number of patients has been treated - up to 166 in 2010. Complications and outcome were registered in an online database.

OBJECTIVES

The aim of this study was to analyse complications and outcome after implementation.

METHODS

Data were retrieved from an online database to which all centres had contributed.

RESULTS

In 3 years, 332 patients were treated. Excluding 24 patients with congenital abnormalities or metabolic disorders, mortality was 31.8%. Of the 210 survivors without congenital malformations, 21 had cerebral palsy, another 19 a developmental delay of more than 3 months at the age of at least 24 months, and 2 had severe hearing loss. The total adverse outcome, combining death and adverse neurodevelopment, in 308 patients without congenital malformations is 45.5%, which is similar to that of the large trials.

CONCLUSIONS

The introduction of therapeutic hypothermia for neonates with perinatal asphyxia in the Netherlands and Flanders has been rapid and successful, with results similar to findings in the randomised controlled trials.

Neurotrophin-induced migration and neuronal differentiation of multipotent astrocytic stem cells in vitro

Hypoxic ischemic encephalopathy (HIE) affects 2-3 per 1000 full-term neonates. Up to 75% of newborns with severe HIE die or have severe neurological handicaps. Stem cell therapy offers the potential to replace HIE-damaged cells and enhances the autoregeneration process. Our laboratory implanted Multipotent Astrocytic Stem Cells (MASCs) into a neonatal rat model of hypoxia-ischemia (HI) and demonstrated that MASCs move to areas of injury in the cortex and hippocampus. However, only a small proportion of the implanted MASCs differentiated into neurons. MASCs injected into control pups did not move into the cortex or differentiate into neurons. We do not know the mechanism by which the MASCs moved from the site of injection to the injured cortex. We found neurotrophins present after the hypoxic-ischemic milieu and hypothesized that neurotrophins could enhance the migration and differentiation of MASCs. Using a Boyden chamber device, we demonstrated that neurotrophins potentiate the in vitro migration of stem cells. NGF, GDNF, BDNF and NT-3 increased stem cell migration when compared to a chemokinesis control. Also, MASCs had increased differentiation toward neuronal phenotypes when these neurotrophins were added to MASC culture tissue. Due to this finding, we believed neurotrophins could guide migration and differentiation of stem cell transplants after brain injury.

Congenital diaphragmatic hernia repair during whole body hypothermia for neonatal hypoxic ischemic encephalopathy

Major malformations, surgery and persistent pulmonary hypertension (PHT) have been considered contraindications to therapeutic hypothermia (TH) in newborns with hypoxic-ischemic encephalopathy (HIE). We report two patients with undiagnosed congenital diaphragmatic hernia (CDH) who developed HIE after birth. Diagnosis of moderate HIE was formulated based on clinical, laboratory and electroencephalographic criteria. The patients were treated with whole body hypothermia (33.5 °C) for 72 h. During hypothermia the patients underwent surgical repair with regular perioperative course. Ventilatory support with high-frequency oscillatory ventilation, oxygen requirements and inotropic support remained stable during hypothermia. Serial echocardiographic evaluations did not demonstrate any change in pulmonary pressure values. In our experience TH did not increase the risk of hemodynamic instability, PHT or bleeding. Hypothermia may be considered in patients with HIE and CDH or other surgical conditions with favorable prognosis.

[Targeted temperature management in critical care : current 2011 recommendations]

Since October 2011 new guidelines exist for temperature management in critical care. According to the guidelines the term targeted temperature management (TTM) should replace the term therapeutic hypothermia. There is now a strong recommendation for TTM using 32-34°C as the preferred treatment for out-of-hospital adult cardiac arrest with a first registered electrocardiography rhythm of ventricular fibrillation or pulseless ventricular tachycardia and still unconscious after restoration of spontaneous circulation. A TTM of 32.5-35.5°C is also recommended for the treatment of term newborns who sustain asphyxia and exhibit acidosis and/or encephalopathy.

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.

Effect of inborn vs. outborn delivery on neurodevelopmental outcomes in infants with hypoxic-ischemic encephalopathy: secondary analyses of the NICHD whole-body cooling trial

BACKGROUND

The effect of birth location on hypothermia-related outcomes has not been rigorously examined in the literature. In this study, we determined whether birth location had an impact on the benefits of whole-body cooling to 33.5 °C for 72 h in term infants (n = 208) with hypoxic-ischemic encephalopathy (HIE) who participated in the Neonatal Research Network (NRN) randomized controlled trial.

METHODS

Heterogeneity by birth location was examined with respect to cooling treatment for the 18-mo primary outcomes (death, moderate disability, severe disability) and secondary outcomes (death, components of disability), and in-hospital organ dysfunction. Logistic regression models were used to generate adjusted odds ratios.

RESULTS

Infants born at a location other than an NRN center (outborn) (n = 93) experienced significant delays in initiation of therapy (mean (SD): 5.5 (1.1) vs. 4.4 (1.2) h), lower baseline temperatures (36.6 (1.2) vs. 37.1 (0.9) °C), and more severe HIE (43 vs. 29%) than infants born in an NRN center (inborn) (n = 115). Maternal education <12 y (50 vs. 14%) and African-American ethnicity (43 vs. 25%) were more common in the inborn group. When adjusted for NRN center and HIE severity, there were no significant differences in 18-mo outcomes or in-hospital organ dysfunction between inborn and outborn infants.

CONCLUSION

Although limited by sample size and some differences in baseline characteristics, the study showed that birth location does not appear to modify the treatment effect of hypothermia after HIE.

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.

Obstetric parameters and Doppler findings in cerebral circulation as predictors of 1 year neurodevelopmental outcome in asphyxiated infants

OBJECTIVE

To establish the association of cardiotocography (CTG) and other obstetric parameters with pulsed Doppler findings in cerebral arteries during the first day of life, and to compare the cerebral artery Doppler with other determinants of asphyxia in predicting 1-year neurological outcome in asphyxiated full-term infants.

STUDY DESIGN

Cerebral blood flow velocity (CBFV) were measured from the anterior cerebral (ACA) and basilar (BA) arteries in 30 asphyxiated and 30 healthy-term infants using pulsed Doppler ultrasonography at approximately 24 h of age. CTG, cord artery pH, Apgar scores, biochemical asphyxia markers and symptoms of hypoxic-ischemic encephalopathy (HIE) were compared with the Doppler findings in respect of the ability to predict the outcome, defined by death or impaired neurological performance at 1 year of age.

RESULT

In all, 20% of the asphyxiated infants but none in the control group had increased peak systolic CBFVs (mean+3 s.d.) in the ACA or BA. The sensitivity of increased systolic CBFV to predict abnormal outcome in the asphyxia group was 83%, specificity 95% and the sensitivity of the combination of HIE grade from 2 to 3 and increased systolic CBFV in the ACA or BA was 100% and specificity was 95%, respectively. Pathological CTG and low cord artery pH or low Apgar scores showed low predictive power.

CONCLUSION

Grade from 2 to 3 HIE and the systolic CBFV (mean+3 s.d.) in the ACA or BA by Doppler ultrasound seemed to predict the outcome in asphyxiated infants at 1 year of age better than CTG, acid basement status, Apgar scores or asphyxia markers. If an increase of more than +3 s.d. in the systolic CBFV does not occur within the first 24 h of life, a good 1-year neurological outcome may be anticipated.

Allopurinol for preventing mortality and morbidity in newborn infants with hypoxic-ischaemic encephalopathy

BACKGROUND

Delayed neuronal death following a perinatal hypoxic insult is due partly to xanthine oxidase-mediated production of cytotoxic free radicals. Evidence exists that allopurinol, a xanthine-oxidase inhibitor, reduces delayed cell death in experimental models of perinatal asphyxia and in people with organ reperfusion injury.

OBJECTIVES

To determine the effect of allopurinol on mortality and morbidity in newborn infants with hypoxic-ischaemic encephalopathy.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Group. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2012, Issue 1), MEDLINE (1966 to March 2012), EMBASE (1980 to March 2012), CINAHL (1982 to March 2012), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared allopurinol administration versus placebo or no drug in newborn infants with hypoxic-ischaemic encephalopathy.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

We included three trials in which a total of 114 infants participated. In one trial, participants were exclusively infants with severe encephalopathy. The other trials also included infants with mild and moderately severe encephalopathy. These studies were generally of good methodological quality, but were too small to exclude clinically important effects of allopurinol on mortality and morbidity. Meta-analysis did not reveal a statistically significant difference in the risk of death (typical risk ratio 0.88; 95% confidence interval (95% CI) 0.56 to 1.38; risk difference -0.04; 95% CI -0.18 to 0.10) or a composite of death or severe neurodevelopmental disability (typical risk ratio 0.78; 95% CI 0.56 to 1.08; risk difference -0.14; 95% CI -0.31 to 0.04).

AUTHORS' CONCLUSIONS

The available data are not sufficient to determine whether allopurinol has clinically important benefits for newborn infants with hypoxic-ischaemic encephalopathy. Much larger trials are needed. Such trials could assess allopurinol as an adjunct to therapeutic hypothermia in infants with moderate and severe encephalopathy and should be designed to exclude important effects on mortality and adverse long-term neurodevelopmental outcomes.

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.

The Vermont Oxford Neonatal Encephalopathy Registry: rationale, methods, and initial results

Background

In 2006, the Vermont Oxford Network (VON) established the Neonatal Encephalopathy Registry (NER) to characterize infants born with neonatal encephalopathy, describe evaluations and medical treatments, monitor hypothermic therapy (HT) dissemination, define clinical research questions, and identify opportunities for improved care.

Methods

Eligible infants were ≥ 36 weeks with seizures, altered consciousness (stupor, coma) during the first 72 hours of life, a 5 minute Apgar score of ≤ 3, or receiving HT. Infants with central nervous system birth defects were excluded.

Results

From 2006–2010, 95 centers registered 4232 infants. Of those, 59% suffered a seizure, 50% had a 5 minute Apgar score of ≤ 3, 38% received HT, and 18% had stupor/coma documented on neurologic exam. Some infants experienced more than one eligibility criterion. Only 53% had a cord gas obtained and only 63% had a blood gas obtained within 24 hours of birth, important components for determining HT eligibility. Sixty-four percent received ventilator support, 65% received anticonvulsants, 66% had a head MRI, 23% had a cranial CT, 67% had a full channel encephalogram (EEG) and 33% amplitude integrated EEG. Of all infants, 87% survived.

Conclusions

The VON NER describes the heterogeneous population of infants with NE, the subset that received HT, their patterns of care, and outcomes. The optimal routine care of infants with neonatal encephalopathy is unknown. The registry method is well suited to identify opportunities for improvement in the care of infants affected by NE and study interventions such as HT as they are implemented in clinical practice.

Implementation and conduct of therapeutic hypothermia for perinatal asphyxial encephalopathy in the UK--analysis of national data

BACKGROUND

Delay in implementing new treatments into clinical practice results in considerable health and economic opportunity costs. Data from the UK TOBY Cooling Register provides the opportunity to examine how one new effective therapy for newborn infants suspected of suffering asphyxial encephalopathy--therapeutic hypothermia- was implemented in the UK.

METHODOLOGY/PRINCIPAL FINDINGS

We analysed returned data forms from inception of the Register in December 2006 to the end of July 2011. Data forms were received for 1384 (67%) of the 2069 infants registered. The monthly rate of notifications increased from median {IQR} 18 {15-31} to 33 {30-39} after the announcement of the results of the recent TOBY trial, and to 50 {36-55} after their publication. This rate further increased to 70 {64-83} following official endorsement of the therapy, and is now close to the expected numbers of eligible infants. Cooling was started at 3.3 {1.5-5.5} hours after birth and the time taken to achieve the target 33-34 °C rectal temperature was 1 {0-3} hours. The rectal temperature was in the target range in 83% of measurements. From 2006 to 2011 there was evidence of extension of treatment to slightly less severely affected infants. 278 of 1362 (20%) infants died at 2.9 {1.4-4.1} days of age. The rates of death fell slightly over the period of the Register and, at two years of age cerebral palsy was diagnosed in 22% of infants; half of these were spastic bilateral. Factors independently associated with adverse outcome were clinical seizures prior to cooling (p<0.001) and severely abnormal amplitude integrated EEG (p<0.001).

CONCLUSIONS/SIGNIFICANCE

Therapeutic hypothermia was implemented appropriately within the UK, with significant benefit to patients and the health economy. This may be due in part to participation by neonatal units in clinical trials, the establishment of the national Register, and its endorsement by advisory bodies.

Pharmacokinetics and pharmacodynamics of medication in asphyxiated newborns during controlled hypothermia. The PharmaCool multicenter study

Background

In the Netherlands, perinatal asphyxia (severe perinatal oxygen shortage) necessitating newborn resuscitation occurs in at least 200 of the 180–185.000 newly born infants per year. International randomized controlled trials have demonstrated an improved neurological outcome with therapeutic hypothermia. During hypothermia neonates receive sedative, analgesic, anti-epileptic and antibiotic drugs. So far little information is available how the pharmacokinetics (PK) and pharmacodynamics (PD) of these drugs are influenced by post resuscitation multi organ failure and the metabolic effects of the cooling treatment itself. As a result, evidence based dosing guidelines are lacking. This multicenter observational cohort study was designed to answer the question how hypothermia influences the distribution, metabolism and elimination of commonly used drugs in neonatal intensive care.

Methods/Design

Multicenter cohort study. All term neonates treated with hypothermia for Hypoxic Ischemic Encephalopathy (HIE) resulting from perinatal asphyxia in all ten Dutch Neonatal Intensive Care Units (NICUs) will be eligible for this study. During hypothermia and rewarming blood samples will be taken from indwelling catheters to investigate blood concentrations of several antibiotics, analgesics, sedatives and anti-epileptic drugs. For each individual drug the population PK will be characterized using Nonlinear Mixed Effects Modelling (NONMEM). It will be investigated how clearance and volume of distribution are influenced by hypothermia also taking maturation of neonate into account. Similarly, integrated PK-PD models will be developed relating the time course of drug concentration to pharmacodynamic parameters such as successful seizure treatment; pain assessment and infection clearance.

Discussion

On basis of the derived population PK-PD models dosing guidelines will be developed for the application of drugs during neonatal hypothermia treatment. The results of this study will lead to an evidence based drug treatment of hypothermic neonatal patients. Results will be published in a national web based evidence based paediatric formulary, peer reviewed journals and international paediatric drug references.

Trial registration

NTR2529.

Systemic effects of whole-body cooling to 35 °C, 33.5 °C, and 30 °C in a piglet model of perinatal asphyxia: implications for therapeutic hypothermia

INTRODUCTION

The precise temperature for optimal neuroprotection in infants with neonatal encephalopathy is unclear. Our aim was to assess systemic effects of whole-body cooling to 35 °C, 33.5 °C, and 30 °C in a piglet model of perinatal asphyxia.

METHODS

Twenty-eight anesthetized male piglets aged <24 h underwent hypoxia-ischemia (HI) and were randomized to normothermia or cooling to rectal temperature (Trec) 35 °C, 33.5 °C, or 30 °C during 2-26 h after insult (n = 7 in each group). HR, MABP, and Trec were recorded continuously.

RESULTS

Five animals cooled to 30 °C had fatal cardiac arrests. During 30 °C cooling, heart rate (HR) was lower vs. normothermia (P < 0.001). Although mean arterial blood pressure (MABP) did not vary between groups, more fluid boluses were needed at 30 °C than at normothermia (P < 0.02); dopamine use was higher at 30 °C than at normothermia or 35 °C (P = 0.005 and P = 0.02, respectively). Base deficit was increased at 30 °C at 12, 24, and 36 h vs. all other groups (P < 0.05), pH was acidotic at 36 h vs. normothermia (P = 0.04), and blood glucose was higher for the 30 °C group at 12 h vs. the normothermia and 35 °C groups (P < 0.05). Potassium was lower at 12 h in the 30 °C group vs. the 33.5 °C and 35 °C groups. There was no difference in cortisol level between groups.

DISCUSSION

Cooling to 30 °C led to metabolic derangement and more cardiac arrests and deaths than cooling to 33.5 °C or 35 °C. Inadvertent overcooling should be avoided.

Thermal protection of the newborn in resource-limited environments

Appropriate thermal protection of the newborn prevents hypothermia and its associated burden of morbidity and mortality. Yet, current global birth practices tend to not adequately address this challenge. Here, we discuss the pathophysiology of hypothermia in the newborn, its prevention and therapeutic options with particular attention to resource-limited environments. Newborns are equipped with sophisticated mechanisms of body temperature regulation. Neonatal thermoregulation is a critical function for newborn survival, regulated in the hypothalamus and mediated by endocrine pathways. Hypothermia activates cellular metabolism through shivering and non-shivering thermogenesis. In newborns, optimal temperature ranges are narrow and thermoregulatory mechanisms easily overwhelmed, particularly in premature and low-birth weight infants. Hyperthermia most commonly is associated with dehydration and potentially sepsis. The lack of thermal protection promptly leads to hypothermia, which is associated with detrimental metabolic and other pathophysiological processes. Simple thermal protection strategies are feasible at community and institutional levels in resource-limited environments. Appropriate interventions include skin-to-skin care, breastfeeding and protective clothing or devices. Due to poor provider training and limited awareness of the problem, appropriate thermal care of the newborn is often neglected in many settings. Education and appropriate devices might foster improved hypothermia management through mothers, birth attendants and health care workers. Integration of relatively simple thermal protection interventions into existing mother and child health programs can effectively prevent newborn hypothermia even in resource-limited environments.

Subcutaneous fat necrosis as a complication of therapeutic hypothermia in a term neonate

Subcutaneous fat necrosis of the newborn (SCFN) is a benign self-limited disorder commonly associated with hypothermia and perinatal asphyxia. SCFN secondary to therapeutic whole body hypothermia has rarely been reported. With increasing use of cooling for moderate to severe hypoxic ischemic encephalopathy (HIE), clinicians should recognize this potential complication.