Dreaming and electroencephalographic changes during anesthesia maintained with propofol or desflurane.
BACKGROUND
Dream recall is reportedly more common after propofol than after volatile anesthesia, but this may be due to delayed emergence or more amnesia after longer-acting volatiles. The electroencephalographic signs of dreaming during anesthesia and the differences between propofol and desflurane also are unknown. The authors therefore compared dream recall after propofol- or desflurane-maintained anesthesia and analyzed electroencephalographic patterns in dreamers and nondreamers and in propofol and desflurane patients for similarities to rapid eye movement and non-rapid eye movement sleep.


METHODS
Three hundred patients presenting for noncardiac surgery were randomized to receive propofol- or desflurane-maintained anesthesia. The raw electroencephalogram was recorded from induction until patients were interviewed about dreaming when they became first oriented postoperatively. Using spectral and ordinal methods, the authors quantified the amount of sleep spindle-like activity and high-frequency power in the electroencephalogram.


RESULTS
The incidence of dream recall was similar for propofol (27%) and desflurane (28%) patients. Times to interview were similar (median 20 [range 4-114] vs. 17 [7-86] min; P = 0.1029), but bispectral index values at interview were lower (85 [69-98] vs. 92 [40-98]; P < 0.0001) in propofol than in desflurane patients. During surgery, the raw electroencephalogram of propofol patients showed more and faster spindle activity than in desflurane patients (P < 0.001). The raw electroencephalogram of dreamers showed fewer spindles and more high-frequency power than in nondreamers in the 5 min before interview (P < 0.05).


CONCLUSIONS
Anesthetic-related dreaming seems to occur just before awakening and is associated with a rapid eye movement-like electroencephalographic pattern.
Leslie
Kate
K
Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Parkville, Victoria, Australia. kate.leslie@mh.org.au
Sleigh
Jamie
J
Paech
Michael J
MJ
Voss
Logan
L
Lim
Chiew Woon
CW
Sleigh
Callum
C
D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000077335:Desflurane; D004311:Double-Blind Method; D004325:Dreams / Q000187:drug effects*; D004569:Electroencephalography / Q000187:drug effects*; D023381:Endpoint Determination; D005260:Female; D005283:Fentanyl / Q000627:therapeutic use; D006801:Humans; D007530:Isoflurane / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy / Q000453:epidemiology; D015742:Propofol; D011446:Prospective Studies; D055815:Young Adult
D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000077335:Desflurane; D007530:Isoflurane; D005283:Fentanyl; D015742:Propofol