Hypotension and bradycardia following intraocular acetylcholine injection. Report of a case

Hypotension and bradycardia possibly associated with intraocular injection of acetylcholine

Topically applied drugs are an important part of the pharmacologic management of cataract extraction and lens implant surgery. Acetylcholine facilitates this procedure via its miotic effect on the ciliary body of the eye. Systemic effects can occur with topically administered ophthalmic medications. Acetylcholine has been implicated in several cases of systemic cholinergic effects, such as hypotension, bradycardia, and bronchospasm, following intraocular administration. The patients we present experienced profound hypotension and bradycardia occurring up to 45 minutes after intraocular injection of acetylcholine. Both patients were over 90 years of age and had a history of first-degree atrioventricular block. As cataract surgery and lens implantation become more prevalent in the older ambulatory segment of the geriatric population, healthcare professionals should be aware that these patients may be more sensitive to the pharmacologic effects of medication used during surgery. Monitoring for adverse effects must be performed intraoperatively and several hours postoperatively. Additionally, patients with known conduction abnormalities prior to surgery should be monitored closely and proper emergency equipment and personnel should be available. Pharmacists who investigate adverse drug reactions should consider ophthalmic medications as potential causes for unexplained or suspected adverse drug reactions.

Principles of ophthalmic anesthesia

Ophthalmic surgery presents the anesthesiologist with many unique challenges. The exigencies of this subspecialty include a comprehensive knowledge of ocular physiology and pharmacology and an understanding of the anesthetic implications intrinsic to a wide variety of ophthalmic procedures.

Vascular hypotension and bradycardia following intraocular injection of acetylcholine during cataract surgery

Two patients, an 80-year-old woman and a 70-year-old man, experienced profound systemic hypotension and bradycardia following intraocular acetylcholine administration during cataract surgery. When we compared these two cases with three previously published reports of similar occurrences, we found no common factors other than age that might have predisposed these patients to such complications. All five patients were in relatively good health and each received different combinations of premedication. This reaction occurred in two patients given local anesthesia, two given local anesthesia with intravenous sedation, and one given general anesthesia. Although a cause-and-effect relationship has not been proven, the suggestive temporal sequence of events indicated that all patients undergoing cataract surgery in which the use of intraocular acetylcholine is contemplated should be monitored by an anesthesiologist.