Midazolam premedication reduces propofol requirements for sedation during regional anesthesia

Purpose: Propofol is often used for sedation during spinal anesthesia. We i nvestigated the effects of midazolam premedication on the propofol requirem ents and incidence of complications during sedation. Methods: In a prospective randomized, controlled, and single-blinded study, 50 patients undergoing elective gynecological surgery were randomly divide d into control and midazolam groups. Patients in the midazolam group receiv ed 2 mg midazolam im 30 min before arrival at the operation room. After spi nal anesthesia was instituted with intrathecal injection of hyperbaric tetr acaine, we provided sedation using continuous infusion of propofol, The lev el of sedation was controlled at a level between "eyes closed but reusable to command" and "eyes closed but reusable to mild physical stimulation" by adjusting the infusion rate. During sedation, the propofol requirements and complications were recorded and patients were asked, two hours after the e nd of operation, whether they remembered intraoperative events. Results: In the midazolam group, the loading dose, steady state infusion ra te, and overall infusion rate of propofol were 0.74 mg.kg(-1), 2.86 mg.kg(- 1).hr(-1), and 3.32 mg.kg(-1).hr(-1), respectively, which were about 17% lo wer than those in the control group (P < 0.05). Moreover, midazolam premedi cation reduced the incidence of intraoperative memory (P < 0.05), but had n o effects on other complications. Conclusion: Midazolam premedication reduced propofol requirements and the i ncidence of intraoperative memory during sedation, These effects on sedatio n using propofol during spinal anesthesia are considered beneficial for pat ients.