Gender Effect on Recovery Time Following Isoflurane Administration While Using a Bispectral Index Monitor

摘要

Gender has been implicated as affecting outcomes of anesthesia (Gan et al., 1999; Myles, McLeod, Hunt, & Fletcher, 2001). The literature is replete with studies indicating significant gender differences in analgesic requirements. In contrast, literature comparing gender differences in recovery times following general anesthesia is sparse. Review of the literature found little published research considering recovery variations among genders using volatile inhaled agents; in addition, most of the studies referring to this potential were retrospective in nature. Recovery time differences have been reported between genders during propofol, alfentanil, and nitrous oxide anesthesia (Gan et al., 1999), with women recovering faster than men. Additionally, a prospective cohort study found that women emerged faster than men from general anesthesia but had a slower rate of return to preoperative health status (Myles et al., 2001). The purpose of this study was to further investigate gender differences in recovery times from general anesthesia using isoflurane and the Bispectral Index monitor (BIS). A convenience sample of 30 men and 22 women (ASA classification: I or II) was enrolled. Subjects received a standardized anesthetic of isoflurane and fentanyl. Depth of anesthesia was assessed using clinical parameters and the bispectral index monitor (BIS) monitor. Wake-up time was measured by the number of minutes it took for subjects to meet both of two endpoints (opening of eyes and hand grasp-and-release to command). An average time of 5.6 minutes for women versus 6.87 minutes for men was found. An analysis of covariance (ANCOVA) was performed to determine if there was any effect of gender on wake-up time.