[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.

Evolving understanding of hypoxic-ischemic encephalopathy in the term infant

Our aim was to document changes in the evaluation and prognosis of term-born infants with neonatal encephalopathy of hypoxic-ischemic origin, with particular reference to our own experiences and influences, and to summarize the debate on causation and the relative importance of antenatal and perinatal factors. High quality neonatal cranial ultrasound and magnetic resonance imaging and spectroscopy have enabled the accurate early visualization of different patterns of hypoxic-ischemic brain injury and prediction of their associated outcomes. Long-term follow-up shows that cognitive and memory difficulties may follow even in children without motor deficits. The very early use of electrophysiologic methods has allowed broad prognostic categorization of infants when this is not possible from clinical assessment or imaging, providing a rationale for entry into intervention trials, such as therapeutic hypothermia. This work has also shown that most of these infants have evidence of acute hypoxic-ischemic brain injury that explains their symptoms and outcomes.