Nitrous Oxide for Analgesia During Office Urethral Bulking

This study is designed to determine primarily if there is a difference in perceived pain in patients receiving urethral bulking with calcium hydroxylapatite using local lidocaine versus local lidocaine plus nitrous oxide gas. Patients will be randomized to a control group (local lidocaine plus room air) or a intervention group (local lidocaine plus 50% nitrous oxide/50% oxygen inhaled mixture). Their pain will be assessed immediately after the procedure, and their recollection of pain will also be assessed at their 2 week post-procedure visit. There are other secondary outcome measures as well; please see outcome measures section for full description.