The infusion method trial of void vs standard catheter removal in the outpatient setting: a prospective randomized trial

OBJECTIVE center dot To ascertain if filling the bladder with warm normal saline before trial of void (TOV) reduces time to decision of outcome of TOV and time to discharge compared with standard in-dwelling catheter (IDC) removal in the outpatient setting. PATIENTS AND METHODS center dot A prospective randomized controlled trial (not blinded) was carried out in the day procedure unit. Randomization was done using computer-generated random numbers. The sample size was calculated based on initial pilot data using alpha = 0.05 and beta = 0.2 and a clinically important reduction of >= 60 min for time to decision of outcome of TOV (primary outcome measure). center dot In all, 60 consecutive patients were recruited from two referral sources: presentations of acute urinary retention to the emergency department and patients discharged home after failing TOV postoperatively. center dot The infusion method group (32 patients) had 300-500 mL warm normal saline infused into the bladder before removing their IDC and the control group (28) had standard IDC removal. center dot Data were collected and analysed using the two-tailed Mann-Whitney U-test. Statistical significance was set at P < 0.05. RESULTS center dot The median time to decision was 135.0 (95% confidence interval CI 95.0-190.0) min in the infusion group and 247.5 (95% CI 189.6-294.1) min in the control group. center dot Patients undergoing a bladder infusion had a shorter discharge time [180.0 (95% CI 126.0-226.9) min] than patients in the standard-IDC-removal group [262.5 (95% CI 233.8-315.0) min]. center dot The infusion arm shortened time to decision by 112.5 min (P < 0.001) and time to discharge by 82.5 min (P < 0.001). center dot Furthermore, patients in the infusion group were 1.56 times more likely to achieve catheter-free state after TOV (risk ratio 1.56, 95% CI 1.03-2.36; P = 0.03). CONCLUSION center dot The infusion method for TOV is safe and expeditious, making it ideal for the outpatient setting. This randomized study shows that the infusion method enables a rapid determination of outcome of TOV with a greater chance of success and shortened discharge times.