Dexmedetomidine for Sedation During Ambulatory Colonoscopy in Older Patients

Aim: This study was designed to test the hypothesis that a Dexmedetomidine (DEX) infusion as a primary sedative would be non inferior to boluses of Midazolam (MDZ) in older patients undergoing ambulatory colonoscopy. Patients and Methods: Fifty ASA physical status I-IV patients undergoing colonoscopy were randomized in this study to receive either (DEX) infusions (n=25) or titrated boluses of (MDZ) (n=25). Meperidine 0.5mg/kg was administered after initial sedation but before the start of the procedure. Patient tolerance was assessed using physiologic variables and side effects associated with both drugs. Verbal pain/anxiety and patient/operator satisfaction were also assessed. Results: As a group, the physiologic characteristics demonstrated no significant differences in the response to the colonoscopy procedure. Although operator satisfaction surveys were similar between groups patient satisfaction was superior with DEX, the incidences of bradycardia and hypotension were more while the adjusted verbal pain and anxiety scores were less in the (DEX) group compared with the (MDZ) group. The total dose of Meperidine was significantly less p 0.05 during the DEX infusions. The increased incidence of nausea and vomiting in the MDZ group is the most likely explanation for the 8-minute delay in time to home readiness compared with the DEX group. Conclusion: This study demonstrates that Dexmedetomidine and Midazolam were equally well tolerated in older patients undergoing ambulatory colonoscopy when administered by an anesthesia provider. This study demonstrates that Dexmedetomidine was efficacious as a sole sedative. Patient satisfaction was superior with DEX.