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Active, Not Recruiting

NCT Number: NCT07074795

Use of Nitrous Oxide During Office Hysteroscopy

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Abnormal Uterine Bleeding Agnosia Endometrial Polyps Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Genital Diseases Genital Diseases, Female Gynatresia Hemorrhage Intrauterine Adhesions Leiomyoma Metrorrhagia Neoplasms Neoplasms by Histologic Type Neoplasms, Connective and Soft Tissue Neoplasms, Muscle Tissue Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Pathologic Processes Pathological Conditions, Signs and Symptoms Perceptual Disorders Postmenopausal Bleeding Retained Products of Conception Signs and Symptoms Urogenital Diseases Uterine Diseases Uterine Fibroids Uterine Hemorrhage

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Mayanei HaYeshua Medical Center

Bnei Brak, 51544, Israel

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy

Procedure

Inhaled nitrous oxide

inhalation of ambient air during office hysteroscopy

Procedure

inhalation of ambient air

Primary outcomes

  1. Comparison of Pain During Office Hysteroscopy Between Inhaled Nitrous Oxide (Treatment Group) and Ambient Air (Placebo Group)

    Time frame: Periprocedural (start to end of the hysteroscopy procedure)

    The difference in pain between the two groups will be assessed using the Visual Analog Scale (VAS), ranging from 0 to 10, where 0 indicates no pain and 10 represents the worst imaginable pain.

    Pain scores will be collected at three time points throughout the procedure

    : uterine entry, during the procedure, and immediately after its completion.

Secondary outcomes

  1. Incidence of side effects related to inhaled substance

    Time frame: Periprocedural (start to end of the hysteroscopy procedure)

    The number and type of side effects reported during the procedure following administration of the inhaled agent (nitrous oxide or ambient air), including nausea, dizziness and presyncope. Adverse events will be recorded and categorized.

  2. Procedure completion

    Time frame: Periprocedural

    Success is defined as the completion of the planned hysteroscopy procedure without the need for an additional intervention - either a repeat hysteroscopy or transfer to the operating room.

    The outcome will be measured as the percentage of participants for whom the procedure was successfully completed as planned.

  3. Patient satisfaction with the procedure

    Time frame: Immediately post-procedure

    Assessed after the procedure by a binary question: "Would you be willing to undergo the same procedure again with the same inhaled agent?" (Yes/No)

Other outcomes

  1. Subgroup differences in pain reduction associated with nitrous oxide during office hysteroscopy

    Time frame: Periprocedural (start to end of the hysteroscopy procedure)

    To evaluate whether specific patient characteristics are associated with greater pain reduction from nitrous oxide use during office hysteroscopy.

    Subgroups include nulliparity, prior surgeries, prolonged procedure duration, type of procedure, and type of hysteroscopic device. Pain will be measured using visual analogue scale (VAS) ranging from 0 to 10, where 0 indicates no pain and 10 represents the worst imaginable pain. Assessments will be performed at three points: uterine entry, during the procedure and immediately after.

  2. Pre-procedural anxiety level assessed using modified State-Trait Anxiety Inventory (STAI)

    Time frame: Immediately before the procedure

    Anxiety levels will be assessed prior to the start of the hysteroscopy using a modified version of the State-Trait Anxiety Inventory (STAI) questionnaire. This tool evaluates both:

    State anxiety (temporary emotional state) Trait anxiety (long-term anxiety disposition) The state subscale includes 5 items, and the trait subscale includes 4 items.

    Each item is scored on a 5-point Likert scale (1 to 5), where:

    1 = lowest anxiety 5 = highest anxiety Total scores are calculated separately for state and trait components. Higher scores indicate greater anxiety.

Sponsors and collaborators

Lead sponsor

Maaynei Hayesha Medical Center

Other

Registry information

Official study title

Nitrous Oxide During Office Hysteroscopy for Reducing Pain and Anxiety

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Jul 20, 2025
Registry last updated
Jul 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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