Dreaming and electroencephalographic changes during anesthesia maintained with propofol or desflurane

Area of Science:

• Anesthesiology
• Neuroscience
• Sleep Medicine

Background:

• Dream recall rates may differ between propofol and volatile anesthesia.
• Previous studies suggest potential confounding factors like emergence time and amnesia.
• Electroencephalographic (EEG) correlates of dreaming under anesthesia are not well understood.

Purpose of the Study:

• To compare dream recall after propofol versus desflurane anesthesia.
• To analyze EEG patterns in patients who dreamed versus those who did not.
• To investigate EEG similarities between dreaming during anesthesia and rapid eye movement (REM) sleep.

Main Methods:

• 300 noncardiac surgery patients were randomized to propofol or desflurane anesthesia.
• Continuous EEG was recorded from induction to postoperative orientation.
• EEG spectral and ordinal analyses quantified sleep spindle and high-frequency activity.

Main Results:

• Dream recall incidence was similar: 27% for propofol, 28% for desflurane.
• EEG showed more and faster spindle activity with propofol compared to desflurane.
• Dreamers exhibited fewer spindles and more high-frequency EEG power before awakening.

Conclusions:

• Anesthetic-related dreaming appears to occur shortly before emergence.
• Dreaming during anesthesia is associated with an EEG pattern resembling REM sleep.