[Clonidine compared to midazolam for intravenous premedication for ambulatory procedures. A controlled double blind study in ASA 1 patients]

Abstract

Objective: Midazolam is frequently used for premedication in day-case surgical patients whereas clonidine is rarely administered for this indication. However, clonidine has several useful effects that make the drug an interesting alternative to conventional premedicants. Thus, in this randomised, double-blind, and controlled study the anxiolytic effect of midazolam was compared to that of clonidine. Furthermore, effects on postoperative complaints and minor complications, and readiness for discharge were investigated.

Methods: 100 ASA-1 patients undergoing wisdom teeth extraction on a day-case basis were included into the analysis. A further 50 patients who received no premedication served as a control group. General anaesthesia was standardised (propofol-fentanyl-isoflurane in N2O/O2). The anxiolytic effect of the premedication was assessed using the Erlanger anxiety- and tension scale (EAS). The test was applied before and after intravenous premedication with 1.5 micrograms/kg clonidine or 50 micrograms/kg midazolam and repeated once postoperatively. During recovery the incidence and severity of pain, nausea and vomiting, and shivering were recorded. The readiness for discharge was assessed using standardised discharge criteria. The recording of data was completed by a telephone interview on the day after surgery.

Results: The demographic data of the groups did not differ. In the two treatment groups there was a time-dependent decrease of anxiety and tension. However, postoperatively there was no difference between the levels of anxiety and inner tension between the premedicated patients and the untreated control group. Furthermore there was no difference in the incidence and severity of any postoperative complications. Time until the patients were ready for discharge did not differ between the three groups.

Conclusion: The effects of an intravenous premedication with 1.5 micrograms/kg clonidine or 50 micrograms/kg midazolam, respectively in young ASA-1 patients undergoing minor surgical procedures on a day-case basis are restricted to decrease of anxiety and inner tension before surgery. No beneficial effects were found during the postoperative period compared with untreated control patients.