EEG and memory effects of low-dose infusions of propofol. Academic Article uri icon

Overview

abstract

  • The purpose of this study was to identify EEG changes associated with low-dose propofol infusion producing only sedative effects, and to describe the memory effects of low-dose propofol infusion. Ten healthy volunteers underwent EEG monitoring (at Fz, Cz, Pz and Oz electrode sites) before, during and after propofol 0.5 mg kg-1 i.v. bolus and 75 micrograms kg-1 min-1 as an infusion. Mean serum concentration of propofol during infusion was 0.86 (SD 0.14) micrograms ml-1. The EEG changed significantly during infusion, with increased power in the beta 1 (15-20 Hz), beta 2 (20.5-30 Hz) and delta (1-3.5 Hz) frequencies. Beta 1 and beta 2 power changes were most marked at the Fz and Cz electrodes. Subjects were sedated, but able to complete cognitive tasks. Visual analogue scales of attention and sleepiness were obtained throughout the study and demonstrated a sedative effect during propofol infusion, but were not a significant factor in memory performance or EEG changes. A verbal learning task (Rey Auditory-Verbal Learning Task) administered before, during and after infusion showed a marked reduction in short-term memory capacity and dramatically impaired free recall and recognition during infusion. Nine of 10 subjects had partial amnesia for complex visual scenes presented during infusion, recalling less than 50% of the material. Stronger cueing was required to retrieve information presented during propofol infusion, with an increase in mean retrieval time from 95.4 (41.2) s to 426.8 (83.1) s. EEG and memory effects resolved quickly after the end of infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

publication date

  • September 1, 1992

Research

keywords

  • Anesthesia, Intravenous
  • Electroencephalography
  • Memory
  • Propofol

Identity

Scopus Document Identifier

  • 0026673420

Digital Object Identifier (DOI)

  • 10.1093/bja/69.3.246

PubMed ID

  • 1389841

Additional Document Info

volume

  • 69

issue

  • 3