Robert H. Pfister

Hypothermia and other treatment options for neonatal encephalopathy: an executive summary of the Eunice Kennedy Shriver NICHD workshop.

HIE is not a single disease from a single cause, and is characterized by great diversity in the timing and magnitude of brain injury. It is therefore unreasonable to expect any single intervention to provide uniformly favorable outcome. The known heterogeneity in neuropathological changes after perinatal HIE combined with potential regional heterogeneity of treatment effects will lead to marked differential effects on outcomes among survivors of HIE (e.g. physical disability versus cognitive deficits). This underscores the need for longer term follow up of all infants with HIE undergoing any treatment. In spite of rapidly accumulating clinical and laboratory data related to hypothermia as a neuroprotective strategy for HIE, the speakers and discussants at the workshop underscored numerous gaps in knowledge in this field summarized in the Table, which compares the gaps identified at the 2005 NICHD workshop8 with current gaps. The participants noted that with only six completed studies1-6 providing information on follow-up for up to 18 months of age, the longer-term neurodevelopmental impact of hypothermia for HIE are pending.23,24 This, they concluded, should lead to an overall measure of caution in applying the new therapy of hypothermia indiscriminately for all cases of HIE. Table 1 Comparison of Categories of Gaps in Knowledge and Change from 2005 to 2010 Based on the available data and large knowledge gaps, the expert panel suggested that although hypothermia is unequivocally a promising therapy for HIE, a substantial proportion of infants still suffer from death or disability despite treatment. Further analysis of existing trial data, development of adjuvant therapies to hypothermia, development of biomarkers and further refinements of hypothermia therapy for use in infants suffering from HIE and clinical trials of therapeutic hypothermia in mid resource settings with different risk factors but adequate facilities and infrastructure are all urgently needed and were identified as areas of high priority for study.

Hypothermia and other treatment options for neonatal encephalopathy

HIE is not a single disease from a single cause, and is characterized by great diversity in the timing and magnitude of brain injury. It is therefore unreasonable to expect any single intervention to provide uniformly favorable outcome. The known heterogeneity in neuropathological changes after perinatal HIE combined with potential regional heterogeneity of treatment effects will lead to marked differential effects on outcomes among survivors of HIE (e.g. physical disability versus cognitive deficits). This underscores the need for longer term follow up of all infants with HIE undergoing any treatment. In spite of rapidly accumulating clinical and laboratory data related to hypothermia as a neuroprotective strategy for HIE, the speakers and discussants at the workshop underscored numerous gaps in knowledge in this field summarized in the Table, which compares the gaps identified at the 2005 NICHD workshop8 with current gaps. The participants noted that with only six completed studies1-6 providing information on follow-up for up to 18 months of age, the longer-term neurodevelopmental impact of hypothermia for HIE are pending.23,24 This, they concluded, should lead to an overall measure of caution in applying the new therapy of hypothermia indiscriminately for all cases of HIE. Table 1 Comparison of Categories of Gaps in Knowledge and Change from 2005 to 2010 Based on the available data and large knowledge gaps, the expert panel suggested that although hypothermia is unequivocally a promising therapy for HIE, a substantial proportion of infants still suffer from death or disability despite treatment. Further analysis of existing trial data, development of adjuvant therapies to hypothermia, development of biomarkers and further refinements of hypothermia therapy for use in infants suffering from HIE and clinical trials of therapeutic hypothermia in mid resource settings with different risk factors but adequate facilities and infrastructure are all urgently needed and were identified as areas of high priority for study.

New synthetic surfactants: the next generation?

Surfactant preparations have been proven to improve clinical outcome of infants at risk for or having respiratory distress syndrome (RDS). In clinical trials, ani mal-derived surfactant preparations reduce the risk of pneumothorax and mortality when compared to non-protein-containing synthetic surfactant preparations. In part, this is thought to be due to the presence of surfactant proteins in animal-derived surfactant preparations. Four native surfactant proteins have been identified. The hydrophobic surfactant proteins B (SP-B) and C (SP-C) are tightly bound to phospholipids. These proteins have important roles in maintaining the surface tension-lowering properties of pulmonary surfactant. Surfactant protein A (SP-A) and D (SP-D) are extremely hydrophilic and are not retained in the preparation of any commercial animal-derived surfactant products. These proteins are thought to have a role in recycling surfactant and improving host defense. There is concern that animal-derived products may have some batch-to-batch variation regarding the levels of native pulmonary surfactant proteins. In addition, there is concern regarding the hypothetical risk of transmission of viral or unconventional infectious agents from an animal source. New surfactant preparations, composed of synthetic phospholipids and essential hydrophobic surfactant protein analogs, have been developed. These surfactant protein analogs have been produced by peptide synthesis and recombinant technology to provide a new class of synthetic surfactants that may be a suitable alternative to animal-derived surfactants. Preliminary clinical studies have shown that treatment with these novel surfactant preparations can ameliorate RDS and improve clinical outcome. Clinicians will need to further understand any differences in clinical effects between available products.

Antecedents of Neonatal Encephalopathy in the Vermont Oxford Network Encephalopathy Registry

BACKGROUND: Neonatal encephalopathy (NE) is a major predictor of death and long-term neurologic disability, but there are few studies of antecedents of NE. OBJECTIVES: To identify antecedents in a large registry of infants who had NE. METHODS: This was a maternal and infant record review of 4165 singleton neonates, gestational age of ≥36 weeks, meeting criteria for inclusion in the Vermont Oxford Network Neonatal Encephalopathy Registry. RESULTS: Clinically recognized seizures were the most prevalent condition (60%); 49% had a 5-minute Apgar score of ≤3 and 18% had a reduced level of consciousness. An abnormal maternal or fetal condition predated labor in 46%; maternal hypertension (16%) or small for gestational age (16%) were the most frequent risk factors. In 8%, birth defects were identified. The most prevalent birth complication was elevated maternal temperature in labor of ≥37.5°C in 27% of mothers with documented temperatures compared with 2% to 3.2% in controls in population-based studies. Clinical chorioamnionitis, prolonged membrane rupture, and maternal hypothyroidism exceeded rates in published controls. Acute asphyxial indicators were reported in 15% (in 35% if fetal bradycardia included) and inflammatory indicators in 24%. Almost one-half had neither asphyxial nor inflammatory indicators. Although most infants with NE were observably ill since the first minutes of life, only 54% of placentas were submitted for examination. CONCLUSIONS: Clinically recognized asphyxial birth events, indicators of intrauterine exposure to inflammation, fetal growth restriction, and birth defects were each observed in term infants with NE, but much of NE in this large registry remained unexplained.

Initial Respiratory Support of Preterm Infants: The Role of CPAP, the INSURE Method, and Noninvasive Ventilation

This article explores the potential benefits and risks for the various approaches to the initial respiratory management of preterm infants. The authors focus on the evidence for the increasingly used strategies of initial respiratory support of preterm infants with continuous positive airway pressure (CPAP) beginning in the delivery room or very early in the hospital course and blended strategies involving the early administration of surfactant replacement followed by immediate extubation and stabilization on CPAP. Where possible, the evidence referenced in this review comes from individual randomized controlled trials or meta-analyses of those trials.

The Vermont oxford neonatal encephalopathy registry: Rationale, methods, and initial results

BackgroundIn 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.MethodsEligible 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.ResultsFrom 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.ConclusionsThe 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.

Neuroimaging in the Evaluation of Neonatal Encephalopathy

BACKGROUND AND OBJECTIVE: Computed tomography (CT) is still used for neuroimaging of infants with known or suspected neurologic disorders. Alternative neuroimaging options that do not expose the immature brain to radiation include MRI and cranial ultrasound. We aim to characterize and compare the use and findings of neuroimaging modalities, especially CT, in infants with neonatal encephalopathy. METHODS: The Vermont Oxford Network Neonatal Encephalopathy Registry enrolled 4171 infants (≥36 weeks’ gestation or treated with therapeutic hypothermia) between 2006 and 2010 who were diagnosed with encephalopathy in the first 3 days of life. Demographic, perinatal, and medical conditions were recorded, along with treatments, comorbidities, and outcomes. The modality, timing, and results of neuroimaging were also collected. RESULTS: CT scans were performed on 933 of 4107 (22.7%) infants, and 100 of 921 (10.9%) of those received multiple CT scans. Compared with MRI, CT provided less detailed evaluation of cerebral injury in areas of prognostic significance, but was more sensitive than cranial ultrasound for hemorrhage and deep brain structural abnormalities. CONCLUSIONS: CT is commonly used for neuroimaging in newborn infants with neonatal encephalopathy despite concerns over potential harm from radiation exposure. The diagnostic performance of CT is inferior to MRI in identifying neonatal brain injury. Our data suggest that using cranial ultrasound for screening, followed by MRI would be more appropriate than CT at any stage to evaluate infants with neonatal encephalopathy.

Evidence-Based Delivery Room Care of the Very Low Birth Weight Infant

The first hour of a newborn’s life is fraught with difficulty. Recommendations regarding the fundamental issues of resuscitation of these infants are developed and disseminated by the International Liaison Committee on Resuscitation and other organizations. However, these recommendations frequently do not address the needs of the very low birth weight infant and do not address some of the nuances that might lead to improved outcome. Improved organization and teamwork as well as improved monitoring and respiratory support can potentially improve the outcome of these infants.

Quality Improvement in Respiratory Care: Decreasing Bronchopulmonary Dysplasia

Chronic lung disease (CLD) is one of the most common long-term complications in very preterm infants. Bronchopulmonary dysplasia (BPD) is the most common cause of CLD in infancy. Modern neonatal respiratory care has witnessed the emergence of a new BPD that exhibits decreased fibrosis and emphysema, but also decreased alveolar septation, and microvascular development. CLD encompasses the classic and the new BPD, and recognizes that lung injury can occur in term infants who need aggressive ventilatory support and who develop lung injury as a result, and that CLD is a multisystem disease. Controversy exists on whether quality improvement (QI) methods that implement multiple interventions will be effective in limiting pathology with multiple causes. Caution in generalization of QI findings is encouraged. QI methods toward improvement in CLD or any other outcome should be considered as a tool for implementing evidence and studying the effects of change in complex adaptive systems.

Contents Vol. 99, 2011

S. Andersson, Helsinki E. Bancalari, Miami, Fla. J. Bhatia, Augusta, Ga. G. Buonocore, Siena W. Carlo, Birmingham, Ala. I. Choonara, Derby T. Curstedt, Stockholm C. Dani, Florence B. Darlow, Christchurch M. Fujimura, Osaka M. Hallman, Oulu W.W. Hay, Jr., Aurora, Colo. S.E. Juul, Seattle, Wash. M. Kaplan, Jerusalem B. Kramer, Maastricht R.J. Martin, Cleveland, Ohio C.J. Morley, Cambridge J. Neu, Gainesville, Fla. P.C. Ng, Hong Kong M.W. Obladen, Berlin A.G.S. Philip, Sebastopol, Calif. M. Post, Toronto E. Saliba, Tours O.D. Saugstad, Oslo M.S. Schimmel, Jerusalem B. Schmidt, Philadelphia, Pa. M.P. Sherman, Columbia, Mo. E.S. Shinwell, Rehovot K. Simmer, Perth, W.A. J. Smith, Tygerberg B. Sun, Shanghai N. Vain, Buenos Aires F. van Bel, Utrecht J.N. van den Anker, Washington, D.C. M. Vento Torres, Valencia M. Weindling, Liverpool J.A. Widness, Iowa City, Iowa Fetal and Neonatal Research