Resting State EEG Characteristics During Sedation With Midazolam or Propofol in Older Subjects

Abstract

Background. Despite widespread application, little is known about the neurophysiological effects of light sedation with midazolam or propofol, particularly in older subjects. The aim of this study was to assess the effects of light sedation with midazolam or propofol on a variety of EEG measures in older subjects. Methods. In patients (≥60 years without neuropsychiatric disease such as delirium), 2 EEG recordings were performed, before and after administration of either midazolam (n = 22) or propofol (n = 26) to facilitate an endoscopic procedure. Power spectrum, functional connectivity, and network topology based on the minimum spanning tree (MST) were compared within subjects. Results. Midazolam and propofol administration resulted in Richmond Agitation and Sedation Scale levels between 0 and −4 and between −2 and −4, respectively. Both agents altered the power spectra with increased delta (0.5-4 Hz) and decreased alpha (8-13 Hz) power. Only propofol was found to significantly reduce functional connectivity. In the beta frequency band, the MST was more integrated during midazolam sedation. Propofol sedation resulted in a less integrated network in the alpha frequency band. Conclusion. Despite the different levels of light sedation with midazolam and propofol, similar changes in power were found. Functional connectivity and network topology showed differences between midazolam and propofol sedation. Future research should establish if these differences are caused by the different levels of sedation or the mechanism of action of these agents.

Modulation of simultaneously collected hemodynamic and electrophysiological functional connectivity by ketamine and midazolam

“…generally, these were increases after ketamine (Figure 8m-q), apart from in the alpha band as found previously (Blain-Moraes, Lee, Ku, Noh, & Mashour, 2014;Vlisides et al, 2018), and decreases after midazolam (Figure 8m-q), also previously found (Ferrarelli et al, 2010), although a recent article found no change in overall functional connectivity using PLI (Numan et al, 2019). While the electrophysiological connectivity metric derived from the power envelope more closely resembled fMRI, this method results in a loss of some of the rich temporal information that electrophysiological methods can provide such as true zero-phase synchrony.…”

Beneficial Effect of Sodium Nitrite on EEG Ischaemic Markers in Patients with Subarachnoid Haemorrhage

“…Previous research has found decreases in alpha power with fentanyl, propofol and midazolam administration [36,38]. In our study, alpha power changes from baseline were decreased when patients were sedated.…”

“…On the study day, the EEG was recorded for 20 min before and 60 min during infusion of sodium nitrite or saline. Drugs used for sedation were recorded as sedation is known to influence the EEG [34][35][36][37][38]. The EEG (for a detailed description, see supplemental methods, EEG) was acquired from electrodes Fp(1,2), F(3,4,z), T(3,4), Cz, P (3,4,z) and Oz/O1.…”

A Processed EEG based Brain Anesthetic Resistance Index Predicts Postoperative Delirium in Older Adults: A Dual Center Study

“…A DARS value <27.0 also remained a significant independent predictor of delirium risk in the derivation cohort (OR 5.4, 95% CI: (1.6, 21.1); p<0.014) while accounting for dosage of other anesthetic drugs that can affect EEG parameters (i.e. opioids, 26 non-depolarizing neuromuscular blockers, 27 ketamine, 28 midazolam and propofol 29 ) and the use of epidural anesthesia 30 and/or nitrous oxide 31 (Table 4). None of these other variables were significantly associated with postoperative delirium risk.…”