Predicting Acute Urinary Retention in Patients with Elevated Post-Void Residuals.

OBJECTIVES To perform a retrospective analysis evaluating factors that may predict which men with elevated post-void residuals (PVRs) that were at increased risk to develop acute urinary retention (AUR). METHODS We retrospectively analyzed the records of 44 male patients who had 2 consecutive PVRs greater than 100 ml over a 6-month period. Using regression analysis, we evaluated patient's age, PVR volume, prostate specific antigen (PSA) and transrectal ultrasound prostate volume with respect to development of AUR over 24 months. RESULTS Of the 44 patients, 4 developed AUR. When all factors were considered, prostate volume was determined to be the only that was statistically significant (p = 0.003). A 1-SD increase in prostate volume (12 ml) led to a 19.6% increased risk of developing AUR. There was a strong correlation between PSA and prostate volume (0.787). A regression analysis was then repeated excluding prostate volume. PSA then became a statistically significant predictor of AUR (p = 0.007). A 1-SD increase in PSA (1.377 ng/ml) increased the patients' risk of developing AUR by 12.3%. CONCLUSION In men with an elevated PVR, increased transrectal ultrasound prostate volume or PSA may help predict which patients have an elevated risk of developing AUR within the next 24 months. This information may influence which patients need early surgical intervention versus medical therapy.