PREMEDICATION FOR OUTPATIENT CATARACT-SURGERY - A COMPARATIVE-STUDY OF INTRAMUSCULAR ALFENTANIL, MIDAZOLAM AND PLACEBO

The effects of i.m. alfentanil and midazolam on anxiety, sedation, hemodynamics, oxygen saturation and intraocular pressure were studied in 90 patients scheduled for outpatient cataract surgery with regional anesthesia. The study was randomized, double-blind, placebo-controlled, and performed on outpatients with ASA physical status I-III and mean age 67.7 +/- 11.7 years. Alfentanil (12.5-mu-g/kg) administered into the deltoid muscle had a marked anxiolytic and short sedative effect, and was associated with stable hemodynamics. Midazolam (20-mu-g/kg) administered similarly had a more prolonged anxiolytic and sedative effect, which impaired co-operation in some patients during surgery. The regional blockade was associated with a significant reduction of oxygen saturation (Spo2), regardless of the premedication used (P < 0.05). A slight reduction of intraocular pressure (IOP) was found after premedication, but the change was not statistically significant. We conclude that i.m. alfentanil is well tolerated, and its anxiolytic and short sedative effects make it especially suitable as premedication for day-case cataract surgery.