Oral low-dose midazolam as premedication for intraocular surgery in retrobulbar anesthesia: cardiovascular effects and relief of perioperative anxiety.

The aim was to investigate the efficacy and practicability of oral low-dose premedication with 3.75 mg midazolam (1/2 tablet Dormicum 7.5 mg) for selective intraocular surgery with retrobulbar anesthesia. Forty-six ASA II-III patients were randomly assigned to either group I: midazolam (n = 24) or group II: placebo (n = 22). Sedation was objectively quantified with a scale derived from the Glasgow-Coma-Scale and a verbal self-rating scale. Trait-anxiety was studied with the State-Trait Inventory by Spielberger, perioperative situative anxiety with the Erlanger Anxiety Scale. Cardiovascular variables and oxygenation were automatically monitored. Midazolam produced significant and sufficient sedation and significant anxiolysis. Systolic, diastolic and mean blood pressure were moderately but significantly, reduced. The effect on diastolic pressure was more pronounced. There was no effect on heart-rate. Oxygenation at all times remained well above 90% SpO2. In conclusion low-dose oral midazolam proved to be a single and effective premedication before intraocular surgery under local anesthesia.