Dominant EEG waveforms associated with common anesthetic agents

This is a survey of the dominant electroencephalography (EEG) waveforms seen when using common anesthetic agents.

Content adapted from TrueLearn, Wikipedia, and UWorld. Images are from Wikimedia Commons.

ADDITIONAL TAGS:
DON'T TAKE ANY STRESS, BE GLAD
Delta band: less than 4 Hz; adult slow-wave sleep, babies
Theta band: 5-8 Hz; drowsiness in adults, idling
Alpha band: 9-12 Hz; relax/reflect, closed eyes
Spindle: (Mu or sensorimotor rhythm, 11-15 Hz): synchronous firing of motor neurons in rest / sleep
Beta band: 13-25 Hz; active thinking, focus, high alert, anxious
Gamma band: 26-80 Hz; multi-neuron population for cognitive or motor function
Anesthetic
agent
Primary mechanism of action
EEG during light to moderate sedation
(1.0 MAC equiv)
EEG during deep sedation to general anesthesia
(≥ 1.0 MAC equiv)
Propofol
GABAA receptor potentiation
Alpha (9-12 Hz) and beta (13-25 Hz)
Alpha (9-12 Hz) and slow-delta (0.1-4 Hz)
Sevoflurane
GABAA receptor potentiation (and others)
Alpha (9-12 Hz) and slow-delta (0.1-4 Hz)
Alpha (9-12 Hz),
theta (5-8 Hz), and
slow-delta (0.1-4 Hz)
Dexmedetomidine
Alpha2-adrenergic receptor stimulation
Spindle (9-15 Hz) and slow-delta (0.1-4 Hz)
Slow-delta oscillations (0.1-4 Hz)
Ketamine
NMDA receptor inhibition
Fast beta (13-25) and gamma (26-80 Hz)
Slow-delta oscillations (0.1-4 Hz)