Consensus on the use of neurophysiological tests in the intensive care unit (ICU): electroencephalogram (EEG), evoked potentials (EP), and electroneuromyography (ENMG)

Abstract

Study aim: To provide a consensus of European leading authorities about the optimal use of clinical neurophysiological (CN) tests (electroencephalogram [EEG]; evoked potentials [EP]; electroneuromyography [ENMG]) in the intensive care unit (ICU) and, particularly, about the way to make these tests clinically useful for the management of individual patients.

Methods: This study gathered together several European clinical neurophysiologists and neurointensivists whose leading contributions in the adult or paediatric ICU and in continuous neuromonitoring had been peer-acknowledged. It was based on both a literature review and each participant's own experience. Given the methodological impossibility to gather studies fulfilling criteria of evidence-based medicine, this article essentially relies on expert opinions that were gained after several rounds, in which each expert was invited to communicate his own contribution to all other experts. A complete consensus has been reached when submitting the manuscript.

Results: What the group considered as the best classification systems for EEG and EP abnormalities in the ICU is first presented. CN tests are useful for diagnosis (epilepsy, brain death, and neuromuscular disorders), prognosis (anoxic ischemic encephalopathy, head trauma, and neurologic disturbances of metabolic and toxic origin), and follow-up, in the adult, paediatric, and neonatal ICU. Regarding prognosis, a clear distinction is made between these tests whose abnormalities are indicative of an ominous prognosis and those whose relative normalcy is indicative of a good prognosis. The prognostic significance of any test may vary as a function of coma etiology.

Conclusion: CN provides quantitative functional assessment of the nervous system. It can be used in sedated or curarized patients. Therefore, it should play a major role in the individual assessment of ICU patients.