Abnormal Uterine BleedingNCT07074795
Use of Nitrous Oxide During Office Hysteroscopy
A study testing Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy and inhalation of ambient air during office hysteroscopy in people with Abnormal Uterine Bleeding and Postmenopausal Bleeding, run by Maaynei Hayesha Medical Center at 1 site in Israel.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Abnormal Uterine Bleeding, Postmenopausal Bleeding, Endometrial Polyps
- What is being tested?
- Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy and inhalation of ambient air during office hysteroscopy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 400 participants
- Where
- 1 siteIsrael
- Study dates
- 1 Jul 2025to Jun 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Women aged ≥18 years Scheduled to undergo operative office hysteroscopy for clinical indications
Who cannot join
- 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 locations and contacts
1 site in 1 country.
About this study
Official title: Nitrous Oxide During Office Hysteroscopy for Reducing Pain and Anxiety
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.
Read the detailed 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.
- Conditions
- Abnormal Uterine Bleeding, Postmenopausal Bleeding, Endometrial Polyps, Retained Products of Conception, Uterine Fibroids, Intrauterine Adhesions
- Being tested
- Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy, inhalation of ambient air during office hysteroscopy
- Keywords
- Inhaled nitrous oxide, Office hysteroscopy, Pain management, Visual analogue scale (VAS), Anxiety reduction, Gynecology
- Medical subject headings
- Metrorrhagia, Leiomyoma, Gynatresia, Agnosia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Inhalation of Nitrous Oxide (N₂O) during Office Operative HysteroscopyProcedure or surgery
Inhaled nitrous oxide
inhalation of ambient air during office hysteroscopyProcedure or surgery
inhalation of ambient air
| Study group | Role | What they receive |
|---|---|---|
| treatment- inhaled nitrous oxide | Active comparator | 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). Receives: Procedure: Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy |
| Inhaled ambient air control group | Placebo comparator | 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). Receives: Procedure: inhalation of ambient air during office hysteroscopy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of Pain During Office Hysteroscopy Between Inhaled Nitrous Oxide (Treatment Group) and Ambient Air (Placebo Group)
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.
Measured: Periprocedural (start to end of the hysteroscopy procedure)
Secondary outcomes (3)
Incidence of side effects related to inhaled substance
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.
Measured: Periprocedural (start to end of the hysteroscopy procedure)
Procedure completion
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.
Measured: Periprocedural
Patient satisfaction with the 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)
Measured: Immediately post-procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2025
- Study start1 Jul 2025
- Primary completionJun 2026 (estimated)
- Study completionJun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Abnormal Uterine BleedingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized clinical trial of inhaled nitrous oxide vs inhaled ambient air
- Masking
- Single blind
- Who is masked
- Care provider
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Maaynei Hayesha Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Tamar Zur, Maaynei Hayesha Medical Center
- Investigators
- Tamar Tzur, MD, Principal investigator, Mayanei Hayeshua Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07074795
- Sponsor's protocol ID
- 0002-24mhmc
- Status last verified
- Jul 2025
- First submitted
- 30 Jun 2025
- Last updated
- 20 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD), including pain scores, anxiety scores, demographic characteristics, and procedural outcomes, will be made publicly available through an open-access data repository (e.g., Zenodo) at the time of primary results publication. The data will be freely accessible for academic and research use, with no restrictions or approval required.
Publications
Likis FE, Andrews JC, Collins MR, Lewis RM, Seroogy JJ, Starr SA, Walden RR, McPheeters ML. Nitrous oxide for the management of labor pain: a systematic review. Anesth Analg. 2014 Jan;118(1):153-67. doi: 10.1213/ANE.0b013e3182a7f73c.
PubMed 24356165Buhre W, Disma N, Hendrickx J, DeHert S, Hollmann MW, Huhn R, Jakobsson J, Nagele P, Peyton P, Vutskits L. European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice. Br J Anaesth. 2019 May;122(5):587-604. doi: 10.1016/j.bja.2019.01.023. Epub 2019 Feb 22.
PubMed 30916011Razdolsky S, Yaniv-Tamir R, Raz M, Kolp-Asis S, Katz T, Elbaz L, Tzur T. Nitrous Oxide for Pain Management in Office Hysteroscopy: A Randomized Placebo-Controlled Trial. Obstet Gynecol. 2026 Jul 1;148(1):71-79. doi: 10.1097/AOG.0000000000006282. Epub 2026 Apr 9.
PubMed 41955620
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Nitrous Oxide During Office Hysteroscopy for Reducing Pain and Anxiety
- ClinicalTrials.gov ID
- NCT07074795
- Acronym / sponsor ID
- 0002-24mhmc
- Conditions
- Abnormal Uterine Bleeding, Postmenopausal Bleeding, Endometrial Polyps, Retained Products of Conception, Uterine Fibroids, Intrauterine Adhesions
- Keywords
- Inhaled nitrous oxide, Office hysteroscopy, Pain management, Visual analogue scale (VAS), Anxiety reduction, Gynecology
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Maaynei Hayesha Medical CenterUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- Jun 2026 (estimated)
- Study completion
- Jun 2026 (estimated)
- First posted
- 20 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed 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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (care provider)
- Number of arms
- 2
- Model description
- Randomized clinical trial of inhaled nitrous oxide vs inhaled ambient air
| Arm | Type | Receives |
|---|---|---|
| treatment- inhaled nitrous oxide | Active comparator | Procedure: Inhalation of Nitrous Oxide (N₂O) during Office Operative HysteroscopyParticipants 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). |
| Inhaled ambient air control group | Placebo comparator | Procedure: inhalation of ambient air during office hysteroscopyParticipants 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). |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Women aged ≥18 years Scheduled to undergo operative office hysteroscopy for clinical indications
Key exclusion criteria (3 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Inhalation of Nitrous Oxide (N₂O) during Office Operative HysteroscopyInhaled nitrous oxide | Procedure or surgery | treatment- inhaled nitrous oxide |
| inhalation of ambient air during office hysteroscopyinhalation of ambient air | Procedure or surgery | Inhaled ambient air control group |
Primary outcome
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.
3 secondary outcomes
Incidence of side effects related to inhaled substance
Time frame: Periprocedural (start to end of the hysteroscopy procedure)
Procedure completion
Time frame: Periprocedural
Patient satisfaction with the procedure
Time frame: Immediately post-procedure
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2025.
- Results publication: PubMed 24356165Likis FE, Andrews JC, Collins MR, Lewis RM, Seroogy JJ, Starr SA, Walden RR, McPheeters ML. Nitrous oxide for the management of labor pain: a systematic review. Anesth Analg. 2014 Jan;118(1):153-67. doi: 10.1213/ANE.0b013e3182a7f73c.
- Results publication: PubMed 30916011Buhre W, Disma N, Hendrickx J, DeHert S, Hollmann MW, Huhn R, Jakobsson J, Nagele P, Peyton P, Vutskits L. European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice. Br J Anaesth. 2019 May;122(5):587-604. doi: 10.1016/j.bja.2019.01.023. Epub 2019 Feb 22.
- Derived from this study: PubMed 41955620Razdolsky S, Yaniv-Tamir R, Raz M, Kolp-Asis S, Katz T, Elbaz L, Tzur T. Nitrous Oxide for Pain Management in Office Hysteroscopy: A Randomized Placebo-Controlled Trial. Obstet Gynecol. 2026 Jul 1;148(1):71-79. doi: 10.1097/AOG.0000000000006282. Epub 2026 Apr 9.
- Similar study principle evaluating inhaled nitrous oxide vs oral analgesia during office hysteroscopyLink provided by the sponsor.
- Similar study evaluating inhaled nitrous oxide vs pericervial block during office hysteroscopyLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD), including pain scores, anxiety scores, demographic characteristics, and procedural outcomes, will be made publicly available through an open-access data repository (e.g., Zenodo) at the time of primary results publication. The data will be freely accessible for academic and research use, with no restrictions or approval required.
Related trials for Abnormal Uterine Bleeding
Recruiting
Clinical Impact of Uterine Repair During Cesarean Section With Barbed Suture on the Incidence of Isthmocele
Isthmocele, Cesarean Scar Defect
Recruiting
A Clinical Study of the Aqua Therapeutics Thermal Therapy Vapor Ablation System in Premenopausal Women With Abnormal Uterine Bleeding
Menorrhagia
Enrolling by invitationPhase 1
Combined Ketorolac and Lidocaine Paracervical Block for Office Hysteroscopy
Abnormal Uterine Bleeding, Analgesia
RecruitingObservational study
Association of Ultrasound Features of the Myometrium Suggestive of Adenomyosis and Clinical Symptoms
Adenomyosis of Uterus
Recruiting
Office Hysteroscopy in Postmenopausal Women: A Randomized Trial of Cervical Preparation Strategies
Postmenopausal Women, Intrauterine Diseases
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tamar Tzur, MD principal investigator
Mayanei Hayeshua Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Inhalation of Nitrous Oxide (N₂O) during Office Operative Hysteroscopy and inhalation of ambient air during office hysteroscopy in people with Abnormal Uterine Bleeding and Postmenopausal Bleeding, run by Maaynei Hayesha Medical Center at 1 site in Israel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 20 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Israel. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07074795, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2025.