Management of postoperative urinary retention: a randomized trial of in‐out versus overnight catheterization

Background: There has been no consensus on the best catheterization strategy for the management of postoperative urinary retention. A prospective randomized trial was undertaken to establish the best practice guidelines for the management of postoperative urinary retention. We also evaluated the contemporary incidence of urinary retention following different categories of general surgery and examined risk factors associated with its occurrence. Methods: All patients who underwent elective inpatient surgery between January 2002 and June 2003 were recruited in the study. Patients who developed postoperative urinary retention were randomized to either having in‐out catheterization or placement of an indwelling catheter for 24 h after surgery. Results: A total of 1448 patients were recruited. The overall incidence of urinary retention was 4.1% (n=60). Significant risk factors associated with postoperative urinary retention included old age, anorectal procedures and use of spinal anaesthesia. Comparison of re‐catheterization and urinary tract infection rates between patients who were treated with in‐out versus overnight catheterization showed no significant differences. Conclusions: Postoperative urinary retention should be managed by in‐out catheterization. Indwelling catheterization for 24 h appeared to bestow no additional benefits. The incidence of urinary retention increased with age, anorectal procedures and the use of spinal anaesthesia.