HP34: Usefulness of EEG for patients in ICU with agitation and delirium

Abstract

For patients admitted in Intensive Care Unit [ICU] the genesis of agitation is multifactorial [Thiago Lopes de Almeida, 2016]. In one study on patients with altered mental status, electroencephalography showed that 5% of patients had non- convulsive seizure, 75% of these were in status [Zeller, 2017]. We retrospectively analyzed 63 patients admitted in ICU with different neurological diseases that have had an episode of agitation or confirmed delirium. They were examined with EEG to rule out non-convulsive status epilepticus. The patients were at least 18 years old, with a Richmond Agitation Sedation Scale more than 2. The American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology and modified Salzburg EEG criteria were applied. Results: 2 [3%] of 63 patients presented non convulsive seizure and in 4 cases [6.3%] non-convulsive status epilepticus was confirmed with the following patterns: 25% - with rhythmic delta activity exceeding 0.5/s and clinical and EEG improvements from antiepileptic drugs; 50%- epileptiform discharges ≤2.5 Hz, with fluctuation in morphology, frequency and location. Periodic discharges [PDs] were recorded in 9.5% of 63 patients; in 24 cases [38%] diffuse delta or theta slowing were recorded, in other 16% - sporadic epileptiform discharges and in 27% - no changes. Conclusion: EEG is useful in agitated and confused patients to exclude an ictal phenomenon. It is very important to consider that the results may be influenced by the heterogeneity of the group, patients with various neurological pathologies, the presence of ICU-related artifacts, sedation that might influence the EEG patterns.