Could the incidence of postoperative urinary tract infection be reduced by reversing the sequence of vaginal cleansing and urethral catheterization?

Postoperative urinary tract infection (UTI) is a common hospital infection after gynaecological operations. A prospective randomized study was performed to examine whether the incidence of UTI could be reduced by reversing the sequence of vaginal cleansing and urethral catheterization. Subjects were randomly allocated to: (1) urethral catheterization before vaginal cleansing; and (2) urethral catheterization after vaginal cleansing. Urine cultures were performed immediately after the procedures as the baseline, on the day of catheter removal, and two days after catheter removal. Patients were examined daily after the operation for any urinary symptoms and fever. The incidences of preoperative asymptomatic bacteriuria were similar in both groups, seven of 84 in group 1 vs. eight of 83 in group 2. Among those with negative urine culture before the operation, 77 in group 1 and 75 in group 2, there was no significant difference in postoperative bacteriuria at catheter removal (23 vs. 22) and two days later (35 vs. 42). No significant difference was noted in the incidence of UTI (5 vs. 10, P = 0.25), with a trend towards less UTI in group 1. Voiding discomfort was more common, and fever less common in group 1. There were significant associations between urine culture results at three different occasions. Bacteriuria at catheter removal is associated with a 7.2 times risk of bacteriuria two days later, 2.4 times risk of urinary symptoms and 3.2 times risk of UTI. Routine surveillance at catheter removal is not cost-effective. We conclude that postoperative bacteriuria and UTI are common. Reversing the sequence of the procedures cannot reduce the incidence. There is no evidence to change the status quo.