NO or oxygen will be administered via a scented nasal mask to blind patients to the intervention. NO can be titrated up to a concentration of 70% nitrous oxide and 30% oxygen based on desired analgesic effects per a predetermined sedation scale as part of the University of New Mexico Center for Reproductive Health (UNM CRH) nitrous administration protocol. All patients will be monitored with a pulse-oximeter. The patient will be fitted to their mask once the procedure is ready to begin. A single nurse will administer nitrous oxide and oxygen for all procedures. Every study patient will receive a minimum of 3 minutes of oxygen at the end of the procedure to minimize the side effects of NO. Additional oxygen will be administered as needed if a patient is experiencing residual effects of NO.