Acute Urinary Retention

Abstract

Acute urinary retention (AUR) is a painful urologic emergency specifically characterized by the sudden inability to urinate. It remains the most common urologic emergency managed by urologists worldwide and is a condition seen by all physicians regardless of their specialty. Population-based cohort studies in the United States and Belgium have put the incidence of AUR at 2.2–6.8 episodes per 1,000 man-years, but older studies have it as high as 130 episodes per 1,000 man-years [1–3, 5, 9, 11]. There is a significantly higher rate in the male population with benign prostatic hypertrophy (BPH). Due to the low occurrence rate in women, data on incidence is not readily available for the female population. Across numerous studies, the major risk factors for development of AUR in men are the following: age (age >70, RR 7.8), symptom severity (AUA symptom score >7, RR 3.2), prostate size (volume >30 mL, RR 3.0), and urinary flow rate (flow rate <12 mL/s, RR 3.9) [9, 13, 16]. Age is the predominant risk factor, with a nearly linear increase in incidence with age – up to 10 % of men over the age of 70 and almost one-third of men over the age of 80. While a variety of pathophysiologic mechanisms may contribute to the development of AUR, the three predominant mechanisms are outflow obstruction, neurologic impairment, and overdistension.