Acute Urinary Retention Due to Prostate Enlargement
Definition and Incidence
- The American Urological Association defines acute urinary retention (AUR) as the inability to urinate due to prostate enlargement caused by benign prostatic hyperplasia (BPH), affecting men with a sudden and painful inability to pass urine despite having a full bladder 1, 2
- The incidence of AUR increases with age, from 6.8 episodes per 1,000 patient years in the overall population to 34.7 episodes in men aged 70 and older 3, 2
Pathophysiology
- BPH contributes to urinary obstruction through two primary mechanisms: static component (direct bladder outlet obstruction from enlarged prostatic tissue) and dynamic component (increased smooth muscle tone and resistance within the enlarged gland) 2
- The underlying cause is the proliferation of glandular epithelial tissue, smooth muscle, and connective tissue within the prostatic transition zone 1, 3
Risk Factors
- Age is the primary risk factor, with BPH prevalence reaching 60% by age 60 and 80% by age 80 2
- Larger prostate size (>30cc) significantly increases the risk of AUR 3
- Severe lower urinary tract symptoms (LUTS) are predictive of future AUR 4
Warning Signs
- Progressive worsening of voiding symptoms, including weak urinary stream, hesitancy, intermittency, straining to urinate, and sensation of incomplete emptying, are warning signs for AUR 4
- High post-void residual (PVR) urine volumes indicate impending AUR 4