Urinary retention and post-void residual urine in men: separating truth from tradition

The definitions of acute and chronic urinary retention remain empirical and subject to wide interpretation. Standardized criteria have not been established and many questions remain unanswered. Moreover, the definition of significant post-void residual urine is unclear. We reviewed several aspects of urinary retention that require clarification with the objective of stimulating discussion among urologists to establish an accurate and coherent definition of urinary retention and significant post-void residual urine, and clarify risk factors.

A MEDLINE search for articles written in English and published before April 2007 was done using a list of terms related to urinary retention. Articles not directly relevant to urinary retention or post-void residual urine were excluded.

The term urinary retention lacks precise clinical or urodynamic meaning. Use of this term to describe a symptom, a sign, and a condition further complicates the issue. Many factors can contribute to the development of retention, including bladder outlet obstruction, detrusor underactivity, and neurogenic bladder conditions. Community based studies and clinical trials in patients with benign prostatic enlargement and/or lower urinary tract symptoms yield different estimates of the incidence of retention and only provide information on the epidemiology of acute urinary retention. However, age, previous retention episodes, lower urinary tract symptoms, chronic inflammation, serum prostate specific antigen level, prostate size, and urodynamic variables appear to be predictors of acute urinary retention. Alpha-receptor antagonists and 5alpha-reductase inhibitors may be useful in preventing urinary retention episodes and progressive benign prostatic enlargement. Clinical trials on the short-term use of antimuscarinics have not provided evidence that these agents increase the risk of retention; data on longer term administration are needed.

Clinicians are adopting less invasive approaches (eg pharmacology or catheterization) to treating patients who present with the symptoms, sign, and condition of urinary retention. Faced with an abundance of new data on acute urinary retention, urologists need to reach a consensus about the risks of urinary retention; this may promote movement toward patient centered prevention strategies with tailored treatment options.