Study objective: To compare the intraoperative effects and recovery characteristics when either midazolam or propofol was used for sedation during local or regional anesthesia.
Design: Open-label, randomized study with blinded observer assessing recovery data.
Setting: Outpatients undergoing elective surgical procedures under local or regional anesthesia at Stanford University Hospital, Stanford, California.
Patients: Sixty-eight consenting, unpremedicated ASA physical status I, II, or III patients.
Interventions: After achieving adequate analgesia with local anesthetic solutions, patients were administered a loading dose of either midazolam (4.2 +/- 1.4 mg) or propofol (69 +/- 23 mg) followed by a variable-rate maintenance infusion equal to 8.6 +/- 5.4 mg/h or 265 +/- 185 mg/h, respectively, to maintain a stable level of sedation during the operation.
Measurements and main results: Intraoperative assessments included level of sedation, as well as cardiovascular and respiratory status, at 1- to 5-minute intervals during the operation. Postoperatively, recovery of cognitive and psychomotor function was assessed using analog scales and the digit-symbol substitution test. The overall quality of intraoperative sedation was similar in the two sedative treatment groups. Although midazolam produced less pain on injection and more effective intraoperative amnesia, use of propofol was associated with less postoperative sedation, drowsiness, confusion, clumsiness, and amnesia, as well as more rapid recovery of cognitive function. However, discharge times were similar in the two sedative treatment groups.
Conclusions: Propofol infusion is a clinically useful alternative to midazolam for sedation during ambulatory surgery under local or regional anesthesia.