Predicting outcome in children with hypoxic ischemic encephalopathy.

OBJECTIVE: Hypoxic ischemic encephalopathy (HIE) is common in children, and providing accurate and timely prognostic information is important in determining the appropriate level of care. While practice parameters are available for prognostication in adults, similar reviews are not available for children. This article reviews the current evidence in domains used to provide prognostic information in children with coma due to HIE. These include historical features of the event; physical exam signs; neurophysiologic studies, such as electroencephalogram and evoked potentials; and neuroimaging. DATA SOURCE: A literature search of MEDLINE was performed using the search terms HIE and prognosis cross-referenced in series with specific domains used to provide prognostic information, including physical examination, electroencephalogram, evoked potentials, neuroimaging, and magnetic resonance imaging. The results of these searches were scanned by the authors to identify articles pertaining to children (nonneonates). Further literature was identified from the reference lists of the literature identified by MEDLINE search. Clinical, preclinical, and review articles were identified that were related to the current understanding of prognosis in pediatric HIE. Only literature in English was reviewed.
RESULTS: When performed at least 24 hrs after the inciting event, abnormal exam signs (pupil reactivity and motor response), absent N20 waves bilaterally on somatosensory evoked potentials, electrocerebral silence or burst suppression patterns on electroencephalogram (not due to metabolic or medication etiology), and abnormal magnetic resonance imaging with diffusion restriction in the cortex and basal ganglia are each highly predictive of poor outcome. Combining these modalities improves the overall predictive value.
CONCLUSIONS: All testing provides the best prognostic information several days after hypoxic-ischemic injury, and often multiple tests are required to improve prognostic ability and rule out potentially confounding conditions. Thus, when decisions can be postponed several days, neurologic consultation and testing can provide the best prognostic information to families.