Use of Nitrous Oxide During Office Hysteroscopy

Maaynei Hayesha Medical Center

Status: Active, not recruiting

Conditions: Uterine Fibroids; Intrauterine Adhesions; Retained Products of Conception; Endometrial Polyps; Postmenopausal Bleeding; Abnormal Uterine Bleeding

Treatments: Procedure: Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy; Procedure: inhalation of ambient air during office hysteroscopy

Study type: Interventional

Funder types: Other

Identifiers

NCT07074795

0002-24mhmc

Details and patient eligibility

About

The goal of this clinical trial is to assess the use of inhaled nitrous oxide during office hysteroscopy.

The main questions it aims to answer are:

• Does it reduce pain during the procedure?
• Does it increase the success rate?
• Does it improve patient satisfaction?
• Does it reduce anxiety?
• Which populations benefit more (e.g., parity, menopausal status, number of previous surgeries, type and duration of procedure, and type of device)?

Participants will be asked about their pain levels during the procedure, as well as their anxiety levels. All responses will be recorded.

Written informed consent will be obtained prior to initiation.

Full description

Office hysteroscopy offers a convenient alternative to operating room-based procedures, yet many patients experience pain and anxiety significant enough to interfere with procedural completion. Nitrous oxide is a fast-acting inhaled agent with both analgesic and anxiolytic properties, widely used in outpatient settings across various medical specialties.

This study will investigate the role of nitrous oxide in improving patient tolerability and comfort during office hysteroscopy. Participants will undergo a standardized procedural protocol with either nitrous oxide or ambient air administered via a demand-valve mask system. Comprehensive data on patient responses during the procedure will be collected and analyzed.

The study will also examine variability in patient responses across different subgroups and procedural types. All procedures will adhere to ethical standards, and patient confidentiality will be maintained throughout.

Enrollment: 400 estimated patients

Sex: Female

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

Women aged ≥18 years Scheduled to undergo operative office hysteroscopy for clinical indications

Exclusion criteria

Any contraindications to N₂O, including:

Pneumothorax Significant chronic obstructive pulmonary disease (COPD) Upper airway obstruction Bowel obstruction Middle ear pathology (e.g., recent ear surgery or active ear infection) Severe recent intraocular gas injection Severe vitamin B12 deficiency Known hypersensitivity to N₂O

Women who will decline randomization or unable to provide informed consent.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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400 participants in 2 patient groups, including a placebo group

treatment- inhaled nitrous oxide

Active Comparator group

Description:

Participants in the Nitrous Oxide group will inhale a fixed 50:50 mixture of nitrous oxide (N₂O) and oxygen (O₂), starting one minute prior to the procedure and continuing throughout its duration. The gas is administered via a self-administered demand-valve face mask connected to the Blendox system (Ambulanc®, Italy).

Treatment:

Procedure: Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy

Inhaled ambient air control group

Placebo Comparator group

Description:

Participants in the control group will inhale ambient air starting one minute prior to the procedure and will continue inhalation throughout its duration. The ambient air is administered via a self-administered demand-valve face mask connected to the Blendox system (Ambulanc®, Italy).

Treatment:

Procedure: inhalation of ambient air during office hysteroscopy