Comparison of efficacy of prophylactic ketamine and dexmedetomidine on postoperative bladder catheter-related discomfort

Objectives: To compare the effects of prophylactic ketamine and dexmedetomidine on postoperative bladder catheter-related discomfort/pain in patients undergoing cystoscopy. Methods: This prospective study was conducted on 75 American Society of Anesthesiologists (ASA) I-II patients between 18-75 years of age and undergoing cystoscopy between November 2011 and June 2012 at Hacettepe University Hospital, Ankara, Turkey. Patients were randomly assigned to one of the 3 groups to receive 1 p/kg dexmedetomidine, 250 p/kg intravenous ketamine, or normal saline. All patients were questioned regarding probe-related discomfort, patient satisfaction, and pain at the end of the operation 0 ([t.sub.0]) and 15 ([t.sub.1]), 60 ([t.sub.2]), 120 ([t.sub.3]), and 360 ([t.sub.4]) minutes postoperatively. Evaluations were performed in person at the post-anesthesia care unit, or in ambulatory surgery rooms, or by phone calls. Results: Pain incidence in the dexmedetomidine and ketamine groups (p=0.042) was significantly lower than that in the control group (p=0.044).The sedation scores recorded at [t.sub.0] in the dexmedetomidine and ketamine groups (p=0.004) were significantly higher than that of the control group (p=0.017). Patient groups were similar regarding the rate of hallucinations experienced at [t.sub.1], no patients experienced hallucinations at [t.sub.2], [t.sub.3], or [t.sub.4]. Significantly more patients experienced hallucinations at [t.sub.0] in the ketamine group than in the dexmedetomidine group (p=0.034) and the control group (p=0.005). Conclusion: Dexmedetomidine and ketamine had similar analgesic effects in preventing catheter-related pain; however, dexmedetomidine had a more acceptable side effect profile. To identify the optimal doses of dexmedetomidine and ketamine, more largescale interventional studies are needed. [phrase omitted]