Electrophysiologic effects of propofol sedation.
The scalp electroencephalogram (EEG), the long latency cognitive P300 auditory evoked response (AER), and reaction times were recorded in 10 volunteers sedated with a computer-controlled infusion of propofol to target plasma concentrations of 0.3, 0.6, 0.9, and 1.2 micrograms/mL. The observed mean +/- SE venous plasma concentrations were 0.152 +/- 0.042, 0.372 +/- 0.078, 0.679 +/- 0.104, and 1.065 +/- 0.112 micrograms/mL, respectively. Scalp EEG topographic mapping revealed that beta 1 activation was primarily frontal and central with relative sparing of the temporal lobes. The P300 response was dramatically reduced by propofol in a concentration-dependent manner, even though the subjects were conscious but clearly sedated. Mean +/- SE reaction times were increased by propofol sedation from 347 +/- 35 ms (control) to 391 +/- 48, 460 +/- 70, 549 +/- 64, and 622 +/- 120 ms at increasing mean venous plasma propofol concentrations. The mean percentage +/- SE of correct responses decreased from 98.1 +/- 2.0 (control) to 99.1 +/- 1.7, 87.4 +/- 9.2, 82.8 +/- 12.9, and 69.8 +/- 20.9 at increasing propofol concentrations. Dramatic alterations in the EEG, P300 response, and reaction times were observed, especially with the higher plasma concentrations which produced conscious sedation.
Sneyd
J R
JR
Department of Anesthesiology, University of Michigan, Ann Arbor 48109-0630.
Samra
S K
SK
Davidson
B
B
Kishimoto
T
T
Kadoya
C
C
Domino
E F
EF
D000328:Adult; D001611:Beta Rhythm / Q000187:drug effects*; D016292:Procedural Sedation; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D015742:Propofol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D015742:Propofol