Use of bladder volume measurement assessed with ultrasound to predict postoperative urinary retention

OBJECTIVE: Postoperative urinary retention (POUR) is a common complication after spinal anesthesia. Ultrasound (US) is a simple, non-invasive method to estimate bladder volume before and after surgery. Primary aim of the present study was to investigate utility of bladder volume measured before and after surgery in prediction of POUR risk. Secondary aim was to investigate necessity of urethral catheter use and risk of urethral catheter-related infections. METHODS: Eighty patients who received spinal anesthesia for arthroscopic knee surgery were included in the study. Level and duration of sensory and motor block; bladder volume measured preoperatively, in post-anesthetic care unit (PACU), and when discharged from PACU; use of urethral catheter; and incidence of urinary tract infection data were recorded. RESULTS: POUR was observed in 28.7% of patients. Length of time for sensory block regression was significantly shorter in patients without POUR (p=0.012). Spontaneous urination was not observed in 3 of 23 patients with POUR, although bladder volume was less than 600 mL. Bladder volume over 600 mL without urination was recorded in 20 patients. There was no statistical difference in preoperative bladder volume between patients who did or did not develop POUR. Bladder volume on admission to PACU was higher in patients with POUR (p=0.023). Urgency and dysuria were observed in 5 patients who required urethral catheterization during postoperative period. Urinary tract infection developed in 1 patient. There was no statistical difference in development of urinary tract infection between patient groups who did and did not undergo urethral catheterization. CONCLUSION: Assessment of patient bladder volume with US before arthroscopic knee surgery may be used to foresee development of POUR. Avoiding elective urinary catheterization may reduce urinary infections.