It is commonly recommended to catheterize or closely follow up patients with post-void residual volumes of 150 mL or more, but the frequency of such findings in geriatric hospitalized patients and the need for intervention are unclear.

Post-void residual volumes were measured by ultrasound examination within 14 hours of admission in 464 patients aged 70 years or more who were hospitalized in a regional hospital general internal medicine department. Outcome variables included the need for an indwelling catheter and complications of urinary retention during the hospitalization.

Post-void residual volumes of ≥150 mL were common (23.9%; 111/464) and had the following distribution: 150 to 299 mL, 13.1% (61/464); 300 to 499 mL, 6.4% (30/464); and 500 mL or more, 6% (28/464). The rate of indwelling catheters was 3.2% (15/464). Results of post-void residual volumes did not predict the need for indwelling catheters in those without other criteria, although those with indications for indwelling catheters had a significantly higher frequency of post-void residual volumes ≥500 mL (P < .001) compared with those without such indications.

We conclude that urinary retention in hospitalized geriatric patients is common, but measurements of post-void residual volumes did not have definite clinical utility. However, the study had limited power to determine the benefits or potential harms of urinary catheterization for elevated post-void residual volumes.