A double-blind trial of glycopyrrolate for transesophageal echocardiography

Glycopyrrolate is an anticholinergic agent used to dry oral secretions and has been advocated for routine use with transesophageal echocardiography (TEE). To evaluate the safety and efficacy of glycopyrrolate for this unique application, a prospective double-blind placebo-controlled study of glycopyrrolate was performed in 61 patients who were awake while undergoing TEE. Thirty patients were randomized to the standard dose of glycopyrrolate (0.2 mg intravenously), and 31 patients received 1 ml of saline solution as placebo. Intravenous midazolam was used for sedation in all but one patient. Heart rate, electrocardiogram, blood pressure, and oxygen saturation were continuously monitored before, during, and after TEE. The patients scored their comfort immediately after TEE and were interviewed at 24 hours for side effects. The operator scored the ease of performing the TEE. No complications occurred in either group. Changes in vital signs and oxygen saturation were similar in both groups. The operator ease and patient comfort was similar in both groups. A significantly higher incidence of the following side effects was observed at 24 hours in patients who received glycopyrrolate versus those who received placebo: sore throat, 63% versus 19%; dry mouth, 43% versus 6%; and urinary retention, 16% versus 0% (p < 0.05 for all). No benefit from glycopyrrolate was noted in operator ease or patient comfort. In conclusion, glycopyrrolate is not recommended for routine use when performing TEE on patients who are awake.