A randomized clinical trial of lorazepam for the reduction of postoperative urinary retention

To estimate whether lorazepam can decrease the incidence of postoperative urinary retention after ambulatory gynecologic surgeries.

A randomized clinical trial at an urban academic medical center was performed. Lorazepam (1 mg) or a placebo was administered intravenously 1 hour after ambulatory gynecologic procedures. Ninety patients were randomized to receive lorazepam (n = 47) or a placebo (n = 43). A computer-generated random number table was used for group assignment. Concealment was maintained by the hospital pharmacy, which prepared and dispensed the medication. Physicians, nurses, and patients were blinded to the group assignment. The time of the first spontaneous void and other information about the surgery and recovery were then recorded.

There was no difference in the overall mean time to void between the lorazepam (3.1 +/- 1.2 hours) and placebo (2.8 +/- 2.0 hours) groups (P =.5). The time to void did not correlate with intravenous fluid use, length of procedure, type of procedure, narcotic use, body mass index, age, type of catheterization, or estimated blood loss.

Medium half-life benzodiazepines do not significantly reduce the incidence of postoperative urinary retention.