Characterization of end-of-life electroencephalographic surges in critically ill patients

Neuromonitoring devices to assess level of sedation are now used commonly in many hospital settings. The authors previously reported that electroencephalicgraphic (EEG) spikes frequently occurred after the time of death in patients being neuromonitored at the time of cessation of circulation. In addition to the initial report, end-of-life electrical surges (ELES) have been subsequently documented in animal and human studies by other investigators. The frequency, character, intensity, and significance of ELES are unknown. Some have proposed that patients should not be declared dead for purposes of organ donation prior to the occurrence of an ELES. If clinical practice were altered to await the presence of an ELES, there could be detrimental consequences to donated organs and their recipients. To better characterize ELES, the authors retrospectively assessed the frequency and nature of ELES in serial patients. To better document ELES, they collected neuromonitoring, demographic, and clinical data on consecutive patients who expired while being actively monitored as part of their standard palliative care. These data were retrospectively collected when available as a convenience sample. The authors assessed 35 patients of which 7 were clinically confirmed as brain dead. None of the brain-dead patients displayed an ELES. Thirteen of the 28 remaining patients (46.4%) exhibited an ELES. The ELES observed were demonstrated to have high frequency EEG signal. The mean peak amplitude of ELES as measured by Patient State Index^TM (PSI) was 58.5 ± 25.7. In this preliminary assessment, the authors found that ELES are common in critically ill patients who succumb. The exact cause and significance of ELES remain unknown; further study is warranted.