The goal of this study was to determine whether recovery room monitoring of bladder volume would affect patient outcome after ambulatory surgery. Incidence of urinary retention and times to void and to discharge were compared in 161 patients managed with ultrasound bladder monitoring versus 173 controls without bladder monitoring. Urinary retention was diagnosed by clinical means or by ultrasound, confirmed by bladder catheterization. Patients were required to void or were catheterized before discharge. In the control patients without underlying risk factors for retention, median time to void was 95 min, and retention occurred in 0.8%, which was not significantly different from the ultrasound group (80 min and 0%, respectively). After hernia/anal surgery or spinal/epidural anesthesia, voiding was delayed (130 and 213 min), incidence of retention was increased (17% and 13%), and there was a trend toward earlier voiding (168+/-99 vs. 138+/-68 min) with bladder monitoring. We conclude that most patients at low risk of retention void within 3 h of outpatient surgery; their outcome is unaffected by bladder monitoring. After hernia/anal surgery and spinal/ epidural anesthesia, the likelihood of urinary retention is increased, and ultrasound monitoring facilitates deciding whether such patients should be catheterized.
Implications: Incidence of bladder catheterization and urinary retention were compared in patients managed with and without ultrasound monitoring of bladder volume after outpatient surgery. Monitoring did not alter outcome in patients at low risk of retention, but it facilitated determining when to catheterize patients at high risk of retention (hernia/anal surgery, spinal/epidural anesthesia).