Use of clonidine as a component of the peribulbar block in patients undergoing cataract surgery

Abstract

Background and objectives: This study was designed to determine whether administration of clonidine as a component of a peribulbar block enhanced analgesia increased sedation, improved akinesia, or decreased intraocular pressure.

Methods: A randomized, double-blinded study was undertaken at a University-affiliated tertiary care hospital. Forty outpatients undergoing unilateral cataract surgery by a single surgeon (J.P.) under peribulbar blockade were evaluated. Patients received either 100 microg (1 mL) clonidine or 1 mL preservative-free normal saline mixed with the local anesthetic (7 mL 1% preservative-free lidocaine). A Honan adapter was applied for 10 minutes after block placement. The outcome measures included sedation scores, intraocular pressure (IOP) before and after peribulbar block, need for supplemental block, 24-hour analgesic requirement, and patient satisfaction.

Results: There were no differences between groups with respect to pain, sedation, or satisfaction scores. There was no difference with respect to onset of akinesia. This study revealed no significant difference in baseline IOP and postperibulbar IOP.

Conclusions: Clonidine did not alter, in any appreciable way, the perioperative course for patients undergoing cataract operations. We do not recommend clonidine as a component of a peribulbar block in patients undergoing cataract extraction operations.