Effects of Intra‐Operative Ketamine Administration on Postoperative Catheter‐Related Bladder Discomfort: A Double‐Blind Clinical Trial

PURPOSE: Urinary catheterization during surgery frequently leads to unfavorable signs and symptoms (ie urgency, discomfort, frequency) during recovery. These signs and symptoms are collectively called catheter-related bladder discomfort (CRBD). We hypothesized that preemptive IV ketamine administration prior to intra-operative catheterization would reduce the incidence of CRBD in the postoperative period when compared to placebo. METHODS: The study consisted of 114 adult patients undergoing elective nephrectomy. They were randomized to 2 equal groups of 57 subjects. In the intervention group, IV ketamine (0.5 mg/kg) was administered directly after induction of anesthesia, but before urinary catheterization. The control group received an injection of 2 mL of normal saline. The study evaluated the incidence and severity of CRBD at 0, 1, 2, and 6 hours after commencement of the recovery period. The study also compared the incidence of postoperative nausea and vomiting, hallucinations, sedation, and respiratory depression in the 2 groups. RESULTS: At the 0- and 1-hour evaluations, the incidence and severity of CRBD were lower in the intervention group; however, at the 2- and 6-hour evaluations, there were no significant differences in incidence and severity of CRBD between the 2 groups. A decreased incidence of postoperative nausea and vomiting (PONV) was observed at 2- and 6-hour visits in the intervention group. Also, a higher occurrence of sedation was seen at the 0-hour checkup in the intervention group. CONCLUSION: Preemptive administration of IV ketamine (0.5 mg/kg) can reduce incidence and severity of CRBD in the early postoperative period.