The effect of sevoflurane on implicit memory: a double-blind, randomised study.
Forty-eight gynaecological patients were randomly allocated to three groups (target end-tidal sevoflurane concentration 1.2, 1.5 or 2%), and into subgroups for positive or neutral suggestion. Anaesthesia was induced by inhalation of sevoflurane in oxygen. When the target concentration was achieved, the bispectral index, computed from a bi-frontal electroencephalogram, was noted. One of two eight-word lists was then played to prime implicit memory, followed by a positive or neutral suggestion. After surgery, each patient tried to identify 24 words obscured by background noise. Priming increased the likelihood of identifying words in the 1.2% group only, i.e. there was evidence of implicit memory in this group. There was no evidence of a therapeutic effect of positive suggestion (p = 0.3), but the power of this part of the study was low. The bispectral index did not achieve statistical significance as an indicator of susceptibility to priming.
Department of Anaesthesia, Ealing Hospital NHS Trust, Southall, UK.
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M
Renna
E M
EM
Lang
G G
GG
Lockwood
D000328:Adult; D000769:Anesthesia, Inhalation / Q000523:psychology; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D013509:Gynecologic Surgical Procedures; D006801:Humans; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects; D008738:Methyl Ethers / Q000494:pharmacology*; D008875:Middle Aged; D011184:Postoperative Period; D000077149:Sevoflurane; D013404:Suggestion
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane