Hysteroscopic permanent sterilization with Essure® is increasingly performed in the outpatient setting. No optimal outpatient analgesia regimen has been identified for the Essure® procedure. The investigators propose a study of inhaled nitrous oxide administered with oxygen, hereafter referred to as nitrous oxide (NO), as an intervention to lower pain experienced during the in-office procedure. The investigators hypothesize that, compared to standard oral medications, inhaled NO will decrease patient anxiety associated with the in-office procedure, as well as increase patient satisfaction and provider perceived ease of device insertion.