Propofol and thiopental do not interfere with regional cerebral blood flow response at sedative concentrations.

Background: Anesthetics may affect the regional cerebral blood flow (rCBF) response associated with increased brain activity in humans. rCBF was measured as auditory stimulus rate was increased during propofol and thiopental administration.

Methods: After informed consent, 10 right-handed male volunteer participants (aged 33.

Information loss over time defines the memory defect of propofol: a comparative response with thiopental and dexmedetomidine.

Background: Sedative-hypnotic drugs impair memory, but details regarding the nature of this effect are unknown. The influences of propofol, thiopental, and dexmedetomidine on the performance of a task that isolates specific components of episodic memory function were measured.

Methods: Working (1 intervening item, 6 s) and long-term memory (10 intervening items, 33 s) were tested using auditory words in a continuous recognition task before and during drug administration.

Propofol-induced alpha rhythm.

The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers. The higher concentration resulted in unresponsiveness (lack of response to auditory/tactile stimuli) in all subjects. This report describes the strong frontal-central rhythms apparent in this state using a quantitative description of oscillatory systems underlying the rhythm.

A neuroanatomical construct for the amnesic effects of propofol.

Background: This study was designed to identify neuroanatomical locations of propofol's effects on episodic memory by producing minimal and maximal memory impairment during conscious sedation. Drug-related changes in regional cerebral blood flow (rCBF) were located in comparison with rCBF increases during a simple word memory task.

Methods: Regional cerebral blood flow changes were assessed in 11 healthy volunteers using H215O positron emission tomography (PET) and statistical parametric mapping (SPM99) at 600 and 1,000 ng/ml propofol target concentrations.

Midazolam decreases cerebral blood flow in the left prefrontal cortex in a dose-dependent fashion.

Midazolam, a short-lived benzodiazepine producing sedation and reversible anterograde amnesia, was administered intravenously to 14 healthy male volunteers. Regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) with intravenous H2 15O at either a 'high' midazolam EEG effect (EEG signs of stage 2 sleep), or 'low' midazolam EEG effect (increase in EEG beta power only). Memory tests administered following PET scans showed significant drug-induced impairment in learning and retrieval at the same drug concentration at which PET images were acquired.