Mental aberrations such as awareness, dreams, and hallucinations occur in approximately 11% of adults undergoing general anesthesia, independent of patient demographics or surgical factors.
This incidence of mental aberrations (awareness, dreams, and hallucinations) in 490 adult patients undergoing a variety of surgical procedures was investigated. The total incidence of mental aberrations reported was 11 percent (awareness 1 percent, halluncinations 2 percent, dreams 8 percent). No statistically significant correlation was found between the incidence of unusual mental reactions and the anesthetic agents employed, the age or sex of the patients, or the duration or type of surgical prcedure.
Wilson et al. (1975) studied this question.
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