Effects of midazolam and propofol on EEG detection of epileptiform activity in patients with altered consciousness.

Objective Midazolam and propofol are the most frequently used sedative agents in intensive care units (ICU). Their effects on EEG in patients with altered consciousness received limited attention; we aim to assess their effects on diagnostic yield for epileptiform abnormalities.Methods This retrospective analysis of a multicenter randomized clinical trial (CERTA) included adult patients with acute consciousness disorders. All patients had EEG recordings and they were randomized 1:1 to either a continuous EEG (cEEG) or two routine EEG (rEEG). Patients were stratified according whether or not they received sedative medications and their dosage (combining midazolam and propofol).Results We analyzed 364 patients, 246 (67.6%) received sedative medication. Median dose of propofol was 0.89 mg/kg/h and 0.08 mg/kg/h for midazolam. Sedation was more frequent in structural brain injuries, and lower consciousness scores. Epileptiform discharges were more frequent in cEEG, women, higher consciousness scores, less severe condition, in patients with antiseizure medication (ASM). Sedation was not independently associated with EEG epileptiform activity.Conclusions Despite its potential of suppressing epileptiform activity, we found no difference in terms of detection of epileptiform activity whether patients received sedation or not.Significance Continuously administrated sedation may have less effect on EEG than when administered in bolus.