Preemptive Effect of Intraurethral Instillation of Ketamine-lidocaine Gel on Postoperative Catheter-related Bladder Discomfort after Lumbar Spine Surgery.

BACKGROUND: Catheter-related bladder discomfort (CRBD) is one of the main reasons of agitation after surgery, leading to urgency and frequency during recovery. Ketamine has been used as an effective drug for reducing the signs and severity of this problem. We hypothesized that intraurethral instillation of ketamine-lidocaine gel before urinary catheterization can reduce the incidence of CRBD in the postoperative period.

MATERIALS AND METHODS: A total of 136 male patients, who underwent two-level laminectomy/discectomy were enrolled in this randomized clinical trial. Patients were randomized into the two groups before urinary catheterization. The ketamine group received urethral lubrication with 5 mL xylocaine jelly (2%) in conjunction with 2 mL (100 mg) ketamine. Patients in control group received urethral lubrication with 5 mL xylocaine jelly (2%) in conjunction with 2 mL distilled water. The primary outcome was the incidence of CRBD. CRBD was assessed using four-stage criteria when arriving in the recovery room and at 1, 2, and 6 h after surgery. Postsurgical pain and the number of sedatives given and opioid requirement were also the secondary outcomes in this study.

RESULTS: Intraurethral instillation of ketamine-lidocaine gel reduced the incidence of CRBD at recovery ( P < 0.001) along with a reduction in the severity of CRBD ( P < 0.05) during the 1st and 2nd visit compared with control group. The mean pain intensity score (visual analog scale) and opioid requirement to relieve postsurgical pain were lower in the ketamine group during all the study timepoints from recovery and after transfer to the ward ( P < 0.008). A higher rate of sedation (72% vs. 11%) also was seen at recovery period in the ketamine group ( P < 0.008).

CONCLUSION: Intraurethral instillation of ketamine-lidocaine gel before bladder catheterization is an effective technique for reducing the incidence and severity of postoperative CRBD.