Urinary retention is a common postoperative complication associated with bladder overdistension and the risk of permanent detrusor damage. The goal of this study was to determine predictive factors of early postoperative urinary retention in the postanesthesia care unit (PACU). We prospectively collected, in 313 adult patients, variables including age, gender, previous history of urinary tract symptoms, type of surgery and anesthesia, intraoperative administration of anticholinergics, amount of intraoperative fluids, IV morphine titration, and bladder volume on entry to the PACU. For each patient, bladder volume was measured by ultrasound on entry and before discharge from the PACU. Urinary retention was defined as a bladder volume larger than 600 mL with an inability to void within 30 min. Predictive factors were identified by multivariate analysis. The incidence of urinary retention in the PACU was 16%. In the multivariate analysis only the amount of intraoperative fluids (>or=750 mL; P = 0.02; odds ratio = 2.3), age (>or=50 yr; P = 0.008; odds ratio = 2.4), and bladder volume on entry to PACU (>or=270 mL; P = 0.0001; odds ratio = 4.8) were found to independently increase the risk of urinary retention. Considering the clinical impact of undiagnosed postoperative urinary retention, these results suggest systematic evaluation of bladder volume with a portable ultrasound device in the PACU, especially in patients with risk factors.
Implications: In this observational study, the ultrasound monitoring of bladder volume in the postanesthesia care unit (PACU) revealed that postoperative urinary retention occurred with an incidence of 16%. Age (>or=50 yr), amount of intraoperative fluid volume (>or=750 mL), and bladder volume on entry to PACU (>or=270 mL) were independent predictive factors for this complication.