Clinical trial NCT06661005: Nitrous Oxide for Pain Management During In-Office Gynecology Procedures
Official title: Nitrous Oxide for Pain Management During In-Office Gynecology Procedures
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: EARLY_PHASE1
Conditions: Nitrous Oxide
Lead sponsor: University of Arizona
Sponsor class: OTHER
First posted: 2024-10-28
Enrollment: 3
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 99
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: The patient will be consented for the study at their office visit when the decision is made to schedule them for a procedure meeting inclusion criteria for our study. After the patient is consented, they will be randomized to either nitrous oxide or IV sedation. Depending on their randomization group, they will be scheduled on a "Nitrous Day" or an "IV Sedation Day".
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to evaluate the pain control, patient satisfaction, and efficiency of nitrous oxide used for anesthesia during in-office gynecologic procedures compared to IV sedation. IV sedation for office-based gynecology procedures provides effective anesthesia but requires a recovery time, IV placement, and a ride provided for the patient. Nitrous oxide can be a viable alternative to IV sedation while also reducing recovery time and omitting the need for an IV, NPO status, and a ride home.

Detailed description: Many hysteroscopic procedures require only minimal sedation in order to accomplish adequate pain control and sufficient anesthesia for completion of the procedure. In order to avoid the higher costs and time associated with hospital-based procedures, there is a growing trend to complete these procedures in an office-based setting with IV sedation. With IV sedation, the patients are required to have a ride to and from the appointment, maintain an NPO status for at least 8 hours prior to the appointment, receive proper IV placement prior to the procedure, and remain in the recovery area until anesthesia has worn off, which can take 30 minutes to 1 hour. Several studies in the family planning literature have shown promising results using nitrous oxide for anesthesia during simple in-office procedures such as \*\*\*\*. One pilot study from Madrid demonstrated superior pain control with nitrous oxide when compared to \*\*\*\*.

We believe that nitrous oxide can be a safe, effective, and favorable method for anesthesia for quick and simple office-based gynecologic procedures. Not only will nitrous oxide provide an equal level of pain control, but it also provides several benefits to the patient and the physician. Using nitrous oxide will not require the patient to withstand an uncomfortable IV placement, to maintain NPO status prior to the procedure, or to coordinate a ride before and after the procedure. For the physician, using nitrous oxide for procedures will provide quicker recovery times, allowing physicians to potentially provide services to more patients within a single clinic day.

Nitrous oxide (N2O) was first isolated in 1772 by the English chemist Joseph Priestly and was later discovered to have analgesic properties by Humphry Davy almost twenty years later (Boyle, Goerig, Huang, Priestly). Its role as an analgesic did not take hold until 1863 when Gardner Quincy Colton established the use of nitrous oxide for dental procedures. After its introduction to dentistry, N2O soon became a popular form of pain management in both obstetrics and surgery (Goerig, Huang, Smith).

Nitrous oxide, when inhaled, has both analgesic and anesthetic properties. The exact anesthetic mechanism of action is not completely understood but is thought to be due to non-competitive inhibition of the excitatory NMDA subtype glutamate receptors (Jevtovic). Nitrous oxide provides analgesia by stimulating opioid receptors in the periaqueductal gray matter and noradrenergic receptors in the brainstem, causing a release of endogenous opioids. This release of endogenous opioids dis-inhibits noradrenergic neurons in the brainstem by inhibiting the inhibiting GABA receptors. Consequently, norepinephrine is released into the spinal cord, thereby inhibiting pain signaling (Fujinaga, Sanders).

Although nitrous oxide has been documented as a safe and effective method for pain relief in many areas of medicine, specifically obstetrics, little research exists about its use for pain management for in-office gynecologic procedures. One study by Singh et al evaluated the role of Nitrous Oxide vs no intervention for IUD insertion in nulliparous women and found that nitrous oxide did not reduce pain (Singh). A pilot study by Rubido et al examined nitrous oxide versus no intervention versus paracervical block in women undergoing hysteroscopic polypectomy and found that nitrous oxide outperformed both the control group and paracervical group (Rubido). A third randomized controlled trial studied the superiority of nitrous oxide versus oral analgesia and discovered that nitrous oxide significantly reduced pain scores compared to the control group (Schneider). The purpose of this study is to examine the non-inferiority of nitrous oxide to intravenous sedation for pain management during in-office gynecologic procedures.

Eligibility criteria: Inclusion Criteria:

* Negative UPT
* English speaking,
* At the Banner Women's Institute who are consented for any of the following procedures with sedation: Diagnostic hysteroscopy, Hysteroscopic endometrial biopsy, Hysteroscopy, IUD placement, Hysteroscopic IUD removal, Colposcopy, LEEP

Exclusion Criteria:

* Chronic narcotic use,
* Contraindications to Nitrous oxide (i.e. Vit B12 deficiency, pulmonary disease),
* Indication for general anesthesia in the main operating room
* BMI \>40
* Non-English Speaking

Primary outcomes:
measure: Pain Evaluation
timeFrame: Procedure start time to procedure end time.
measure: Patient Satisfaction
timeFrame: Procedure start time to procedure end time.
Secondary outcomes:
Other outcomes:
Locations:
city: Phoenix
country: United States
facility: Banner University Medical Center Phoenix
state: Arizona
Study officials:
References:
citation: Boyle HE. NITROUS OXIDE: HISTORY AND DEVELOPMENT. Br Med J. 1934 Jan 27;1(3812):153-5. doi: 10.1136/bmj.1.3812.153. No abstract available.
citation: Fujinaga M, Maze M. Neurobiology of nitrous oxide-induced antinociceptive effects. Mol Neurobiol. 2002 Apr;25(2):167-89. doi: 10.1385/MN:25:2:167.
citation: Goerig M, Esch JSA. History of nitrous oxide-with special reference to its early use in Germany. Best Practice & Research Clinical Anaesthesiology. 2001;15(3):313-338.
citation: Huang C, Johnson N. Nitrous Oxide, From the Operating Room to the Emergency Department. Curr Emerg Hosp Med Rep. 2016;4:11-18. doi: 10.1007/s40138-016-0092-3. Epub 2016 Mar 22.
citation: Jevtovic-Todorovic V, Todorovic SM, Mennerick S, Powell S, Dikranian K, Benshoff N, Zorumski CF, Olney JW. Nitrous oxide (laughing gas) is an NMDA antagonist, neuroprotectant and neurotoxin. Nat Med. 1998 Apr;4(4):460-3. doi: 10.1038/nm0498-460.
citation: Del Valle Rubido C, Solano Calvo JA, Rodriguez Miguel A, Delgado Espeja JJ, Gonzalez Hinojosa J, Zapico Goni A. Inhalation analgesia with nitrous oxide versus other analgesic techniques in hysteroscopic polypectomy: a pilot study. J Minim Invasive Gynecol. 2015 May-Jun;22(4):595-600. doi: 10.1016/j.jmig.2015.01.005. Epub 2015 Jan 14.
citation: Sanders RD, Weimann J, Maze M. Biologic effects of nitrous oxide: a mechanistic and toxicologic review. Anesthesiology. 2008 Oct;109(4):707-22. doi: 10.1097/ALN.0b013e3181870a17.
citation: Schneider EN, Riley R, Espey E, Mishra SI, Singh RH. Nitrous oxide for pain management during in-office hysteroscopic sterilization: a randomized controlled trial. Contraception. 2017 Mar;95(3):239-244. doi: 10.1016/j.contraception.2016.09.006. Epub 2016 Sep 9.
citation: Singh RH, Thaxton L, Carr S, Leeman L, Schneider E, Espey E. A randomized controlled trial of nitrous oxide for intrauterine device insertion in nulliparous women. Int J Gynaecol Obstet. 2016 Nov;135(2):145-148. doi: 10.1016/j.ijgo.2016.04.014. Epub 2016 Jul 16.
citation: Smith W. Under the influence. A history of nitrous oxide and oxygen Anesthesia. Park Ridge: The Wood Library Museum of Anesthesiology; 1982