Hysteroscopy (an exam to look inside the uterus) is one of the most frequently performed procedures for patients with cervical or uterine disorders. It is the gold standard for evaluating various intrauterine problems, pre-menopausal and post-menopausal abnormal uterine bleeding, as well as being a vital examination modality for infertility work-up. Although hysteroscopy is a minimally invasive procedure, it is still known to be a painful experience that requires effective analgesia (meaning pain reduction) to achieve maximum patient comfort and cooperation. Historically, opioids, particularly fentanyl, have held precedence as the primary agents for providing analgesia following surgery of this type. However, despite their efficacy, these agents come with notable drawbacks, including the potential for serious side effects such as respiratory depression, addiction, and postoperative nausea and vomiting.

Both magnesium and ketamine are routinely used to reduce pain following this procedure. Both drugs work on the N-methyl-D-aspartate (NMDA) receptor in the brain to reduce pain, and magnesium has an additional effect in that it can relax smooth muscles. Magnesium has been used successfully to reduce the pain associated with menstrual cramps, which is similar to the pain patients experience after hysteroscopy.

A recent study demonstrated the benefits of adding intravenous magnesium with routine anesthesia during hysteroscopy, revealing a significant decrease in postoperative pain and rescue analgesics. However, this study did not compare the effects of magnesium to ketamine, nor did they characterize the nature of the patients' pain. It is unclear if the pain reduction with magnesium comes from its effect on the NMDA receptor or from it's cramp-reduction effect. We seek to establish whether administering IV magnesium, compared to ketamine, can specifically mitigate uterine cramping pain and total opioid consumption in hopes of finding additional safe and effective pain modalities for patients.

This is a prospective, randomized trial enrolling participants undergoing an elective hysteroscopy or Dilation and Curettage (D&C) at Corewell Health William Beaumont University Hospital in Royal Oak. Participants will be randomized to 1 of 3 treatments: Intravenous (IV) Magnesium, IV Push Ketamine, or Placebo. Opioid consumption is recorded via the electronic medical record (EMR), while overall pain and cramping pain will be captured post-procedure in the hospital and 24 hours later via a phone call.

This is a prospective, randomized trial enrolling participants undergoing an elective hysteroscopy or Dilation and Curettage (D&C) at Corewell Health William Beaumont University Hospital in Royal Oak. Participants will be initially contact via phone call 1 week prior to the procedure. If interested in participating, the study will be discussed pre-operatively and consent will be obtained. Baseline data including demographics, gynecological medical and surgical history, social history, allergies, current medications, ASA status, diagnosis, treatment and paucity will be collected.

The participant will be randomized to one of three study arms: IV magnesium, IV push ketamine, or placebo. The participants and evaluators will be blinded to the assigned study arm. The Principal Investigator and Anesthesiologist will not be blinded. All participants will receive standard of care anesthesia care and standard of care for the procedure.

Post-procedure, participants will receive standard of care pain management. Opioid consumption documented in the EMR will be recorded, and pain post-procedure pain will be assessed. Overall pain and cramping pain will be assessed using the Visual Analog Scale (VAS) at 1 hour, 2 hours, and 24 hours post procedure. The 24 hour pain assessment will be completed via phone.

Adverse events will be monitored for 24 hours post operatively.

Inclusion Criteria:

• Patients undergoing an elective hysteroscopy or dilation and curettage (D&C)
• American Society of Anesthesiologists (ASA) Physical Status 1 - 3
• Age 18 years or older

Exclusion Criteria:

• Chronic Pain Patients (taking opioids within one week of procedure)
• Psychiatric Disorders (current treatment for anxiety/depression)
• Allergies to any of the medications that will be administered
• Current use of magnesium, analgesics, antidepressants, anxiolytics, or opioids
• ASA Physical Status 4 or above
• Developmentally delayed patients that would not be able to verbalize pain scores
• Minors (under 18 years of age)
• Pregnant women

Deidentified individual patient data (IPD) may be made available on request to the principal investigator.

Available following final closure of study and publication of results (anticipated December 2026) for up to 2 years (anticipated December 2028).

Deidentified data may be made available on request to the principal investigator for legitimate research use.