Analgesic Effect of Ketamine in Patients Undergoing Hysteroscopic Endometrial Thermal Ablation Surgery

Hypothesis: The intraoperative administration of ketamine will result in a 30% reduction in opiate requirement following endometrial ablation surgery and the intraoperative administration of ketamine will result in a decreased time to meet discharge criteria in the PACU following endometrial ablation surgery.

The research question is "Does intraoperative administration of ketamine result in decreased postoperative opiate requirement and time to discharge from the postanesthesia recovery unit (PACU) following hysteroscopic endometrial ablation".

Preoperatively:

Subjects will be recruited up to 21days prior to the day of surgery. After informed consent is obtained, subjects will be randomly assigned to one of two groups:

Group A: Saline group Group B: 1% Ketamine group

A verbal rating scale (VRS) will be used to assess pain preoperatively. The patient will be asked to identify the severity of pain by indicating on a scale of 0-10 where 0 is "no pain" and 10 is "the worst pain imaginable".

Baseline Quality of Recovery will be obtained. (Appendix F)

Subjects will be randomized prior to surgery to either Group A or Group B. The randomization table is computer generated. There is a 50% allocation to each group.

Intraoperatively:

Standard anesthetic monitoring will be used including monitoring of processed EEG including either the bi-spectral index (BIS) or similar standard of care ASA monitor. A standardized intraoperative anesthetic plan will be utilized by the anesthesia personnel. (Appendix A). Study drug will be prepared and labeled in 10mL syringes by research personnel who will not be involved in the study assessments. Study drug will be administered on initial insertion of Novasure® device (Appendix B).

Postoperatively:

Pain scores in the PACU will be assessed using the VRS upon admission and every 30 minutes thereafter until discharge criteria are met.

Additionally, nausea, vomiting and retching episodes will be recorded using a VRS.

Postoperative analgesic and antiemetic therapy will be standardized and total amounts of these agents will be recorded Assessment of psychomimetic effects including sedation and agitation will be assess postoperatively prior to discharge using the Richmond Agitation/Sedation Scale (Appendix D).

Acute recovery will be assessed using the Modified Post Anesthesia Discharge Scoring System (MPADSS) (Appendix E). A score of 8 or greater will indicate discharge readiness. Time to fulfill discharge criteria will be recorded.

Any other adverse events and medications required will be recorded. These data will be recorded by research personnel who will be blinded to the study group assignments.

Subjects will be contacted by telephone 24 hours after surgery to assess post-discharge quality of recovery (Appendix F).

Eligibility Criteria:
Inclusion Criteria:

* Gender: Female
* Age: 18-65 years
* Non-pregnant, non-lactating
* Surgery: Outpatient hysteroscopic Novasure® endometrial ablation
* Language: English speaking
* Consent: Obtained

Exclusion Criteria:

* Patient refusal
* Under 18 or over age 65
* Non-English Speaking
* Pregnancy, Breast feeding
* Hysteroscopic procedures using Thermachoice® ablation device
* Chronic use or addiction to opiates, sedatives, non-opiate analgesics
* History of heavy alcohol usage (\>4 drinks/day)
* Significant cardiovascular or pulmonary disease
* Psychiatric or emotional disorder
* Allergy to anesthetic agents utilized in the protocol
* Glaucoma
* Thyrotoxicosis