Background: In the present clinical study, oral premedication of 0.15 mg clonidine has been explored with view to anxiolytic effects and physiological stress parameters.
Methods: The study involved 44 patients of ASA-class I-III, all scheduled to undergo ophthalmological surgery under retrobulbar anesthesia (RBA). One hour before RBA 22 patients received 0.15 mg clonidine and 22 patients placebo p.o. The following parameters were assessed at different times perioperatively: oxygenation (SpO2), heart rate, blood pressure, intraocular pressure and anxiety. Anxiolysis was determined using the Erlanger Anxiety Scale.
Results: There were no significant differences among the groups in SpO2 and heart rate. Significantly decreased blood pressures were measured after clonidine premedication (p < 0.01). In contrast to clonidine after placebo the preoperative anxiety increased. Right before operation anxiety was decreased significantly (p < 0.01) by clonidine compared to placebo.
Conclusions: In our opinion, oral clonidine (0.15 mg) is useful for premedication of surgery under RBA.