Sex differences in conscious sedation during upper gastrointestinal panendoscopic examination.

Background/purpose: Sex differences in response to noxious stimuli or analgesia have been demonstrated. We investigated sex differences in conscious sedation during upper gastrointestinal panendoscopic examination with regard to drug dose and entropy scores.

Methods: We investigated sex differences in 30 men and 30 women who were undergoing conscious sedation during upper gastrointestinal panendoscopic examination. The drug mixture was prepared as 5 mg midazolam plus 1 mg alfentanil diluted with normal saline to a volume of 10 mL. An initial injection of 4 mL was followed by an additional 1 mL every 1 minute, until the modified Observer Assessment of Alertness and Sedation (OAAS) rating scale was ≤ 3 when the panendoscope was inserted. Further injection was allowed thereafter. Entropy values, including state entropy (SE) and response entropy (RE), were monitored from baseline to full recovery.

Results: The volume of mixture needed to achieve an OAAS score of ≤ 3 was significantly lower in men than in women (4.4 ± 0.7 mL vs. 4.8 ± 0.8 mL, p = 0.034). The initial drug demand was not significantly influenced by age, body weight, or body height. The RE and SE values at the time of panendoscope insertion were not significantly different between men and women. The total volume for men was also significantly lower than that for women (5.7 ± 1.1 mL vs. 6.5 ± 1.4 mL, p < 0.01). The lowest RE and SE values during the procedure were not significantly different between men and women.

Conclusion: Women need more analgesic agents than men during panendoscopic examination. There was no significant difference between men and women with regard to anesthetic depth and response to noxious stimuli, as revealed by similar SE and RE values.