Despite reviewing 39 eligible trials, few firm conclusions could be reached because of the multiple comparisons considered, the small size of individual trials, and their low quality. Whether or not to use a particular policy is usually a trade-off between the risks of morbidity (especially infection) and risks of recatheterisation.
The infusion trial of micturition.
To compare three methods for a trial of micturition (TOM) (the midnight removal of the catheter, dawn removal, and a new infusion method) in a randomized prospective study.
                A total of 118 consecutive patients who had undergone transurethral resection of the prostate (TURP) or bladder neck incision (BNI) underwent TOM by one of the three methods. In the infusion method, the bladder was filled at a fast-drip rate via the catheter from a bag of normal saline connected by an intravenous supply set. The catheter was then removed, the patient voided and the volume was measured. From the volume of saline remaining, it was possible to calculate the residual volume in the patient.
                The infusion TOM took a mean 13 h less than the other two methods, which were statistically indistinguishable.
                The infusion TOM is safe and simple, is quick to carry out and can be performed at any time. It establishes the completeness of bladder emptying, which helps in the assessment of voiding.