A prospective study of conservatively managed acute urinary retention: prostate size matters.

Objective: To evaluate in a prospective study the medium- to long-term outcome of a policy of conservatively managing acute urinary retention (AUR), arising solely by bladder outlet obstruction caused by benign prostatic enlargement (BPE), and to identify the factors favouring a positive outcome of a trial without catheter (TWOC).

Patients And Methods: All men admitted as an emergency with primary AUR caused by BPE (from August 1997 to March 2000) underwent a TWOC. The following variables were recorded; the nature and duration of any preceding lower urinary tract symptoms, previous episodes of retention, concomitant anticholinergic medication, coexisting constipation, alcohol as a precipitating cause of AUR, previous prostatectomy, confirmed urinary tract infection, residual urine drained on catheterization and prostate size, as determined by a digital rectal examination (DRE) carried out by one consultant urologist in all patients. Those voiding successfully were followed up prospectively using the International Prostate Symptom Score (IPSS), quality-of-life score, urinary flow rate measurement and ultrasonographic measurement of the postvoid residual (PVR).

Results: Of the 40 men with AUR, 22 (55%) voided spontaneously after removing the catheter and continued to do so with mean peak flow rates of 12.2 mL/s and mean PVRs of 69.6 mL over a follow-up of 8-24 months. These patients remained asymptomatic, with a mean IPSS of 5.2 and quality-of-life score of 0.9. These men had a mean prostatic size of 15.9 g and a mean catheterized residual volume of 814 mL, while in those who had an unsuccessful TWOC the mean prostate size was 27.5 g (P = 0.006) and a mean catheterized residual volume of 1062 mL (P = 0.09). Prostate size as assessed by the DRE was the most significant factor in predicting the outcome of a TWOC.

Conclusion: A TWOC is justified in the long-term for men presenting with AUR caused by BPE. Prostate size is the most important factor for predicting the outcome of such a trial.