Low-dose midazolam infusion for oculoplastic surgery under local anaesthesia

Purpose Oculoplastic surgery with infiltration of local anaesthesia at the operative site performed as a day-case procedure is both efficient and cost -effective. Patients considered unsuitable for this because of fear or appr ehension may, however, benefit from per-operative conscious sedation, We so ught to study the efficacy and safety of this using midazolam, a water-solu ble benzodiazepine. Method We have performed a controlled clinical trial comparing the effect o f a low-dose intravenous infusion of midazolam (0.2 mg/ml of normal saline at a rate of 1 mg/h) with saline placebo on 48 subjects undergoing oculopla stic surgery with local anaesthesia. Patients were given pre- and post-oper ative questionnaires assessing, amongst other factors, anxiety levels, pain , degree of reported amnesia and psychomotor recovery. Results Using the low-dose midazolam infusion no adverse cardiorespiratory reactions occurred. Patients receiving midazolam reported remembering signi ficantly less about their operation than controls (p = 0.04) and showed sig nificantly lower state-anxiety after their operation than before (p < 0.02) . This change was not noted in the placebo group. There was no significant difference in the psychomotor performance of patients given midazolam compa red with controls 2 h after surgery. Conclusions A low-dose continuous infusion of midazolam can be used to safe ly provide effective anxiolysis and conscious sedation with good psychomoto r recovery during oculoplastic procedures in a day-case setting.