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.