Use of Nitrous Oxide for Pain Alleviation in Women Undergoing Osmotic Dilator Insertion for Dilatation and Evacuation

October 11, 2022 updated by: Sheba Medical Center

Use of Nitrous Oxide for Pain Alleviation in Women Undergoing Osmotic Dilator Insertion for Second Trimester Dilatation and Evacuation

A randomised control study aiming to examine whether inhaled N2O/O2 during cervical preparation for second trimester dilatation and evacuation with osmotic dilators (laminaria) alleviates pain and is superior to placebo.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Introduction:

Women undergoing second trimester abortion often undergo preparation of the cervix prior to the Dilatation and Evacuation (D&E). Women may undergo preparation with osmotic dilators (laminaria) or prostaglandins, both methods are effective and safe for cervical preparation(1). In our institution, the protocol for cervical preparation in the second trimester with osmotic dilator insertion takes place 24 hours before the procedure in the gynecologic emergency room/clinic. Currently, the protocol does not include any method of pain relief during the cervix preparation procedure.

At this time, besides general anesthesia, there are no satisfactory evidence-based methods for pain alleviation for osmotic dilators insertion. For example, a recent randomized controlled trial showed topical application of lidocaine spray to the cervix before insertion did not result in lower reported pain as compared with placebo(2).

Inhaled nitrous oxide administered with oxygen (N2O/O2) is an acceptable, effective and widely used method for pain relief in short painful pediatric ,dental and urologic procedures(3-5), as well as in the labor room and in the emergency room(6, 7). N2O/O2 has analgesic, anxiolytic and amnestic properties. N2O/O2 has rapid onset and reversal with minimal side effects and few contraindications. Side effects of N2O/O2 are relatively minor and include nausea, dizziness, drowsiness, light-headedness, and diaphoresis. Contraindications include congenital heart defects, pulmonary hypertension, megaloblastic anemia and relatively low blood O2 saturation (<95%)(8, 9).

A recent randomized controlled trial showed inhaled N2O/O2 is associated with less pain compared to oral sedation for pain management during in-office hysteroscopic sterilization(9) To the best of our knowledge, there is no literature regarding the efficacy of use of nitrous oxide for pain alleviation in women undergoing osmotic dilator insertion for second trimester Dilatation and Evacuation.

Goal:

To examine whether inhaled N2O/O2 during cervical preparation for second trimester dilatation and evacuation alleviates pain and is superior to placebo.

Methods:

A prospective randomized placebo-controlled trial consisting of two groups:

Inhaled N2O/O2 (group 1) Placebo group (O2 only) (group 2)

Women undergoing dilatation and evacuation in the second trimester and are about to undergo cervical dilatation with osmotic dilators (laminaria) will be invited to participate in a randomized placebo control trial comparing Inhaled N2O/O2 or placebo (O2 only).

The recruitment and trial will take place in the emergency room/clinic where the women come a day before the D&E for cervical preparation. This procedure is routinely performed in a gynecologic chair without any sedation thus assessing pain scores is possible.

Informed consent will be obtained from each participant. Randomization will be performed using a computer randomization generator. After enrollment, patients will be randomized into one of the two study arms. allocation to the two treatment groups will be concealed in sequentially numbered opaque envelopes that will be opened only by the nurse actually administering the gas (either inhaled N2O/O2 or inhaled oxygen). The participant and physician will be completely blinded to the intervention.

Participants will be asked about their most severe pain during menses and asked to rate it from 0 to 10.

The patient will be placed in the lithotomy position.

Group1: Patients will receive inhaled N2O/O2 (70% N2O and 30% O2). A sterile bivalve speculum will be placed. Laminaria will be inserted. Inhaled N2O/O2 will be stopped after speculum removal.

Group2: Patients will receive inhaled O2 (100% O2). A sterile bivalve speculum will be placed. Laminaria will be inserted. Inhaled O2 will be stopped after speculum removal.

Patients will receive inhaled O2 (100% O2) throughout the procedure until speculum removal.

Pain will be assessed at 7-time intervals using a visual analog pain scale 0 (no pain) to 100 (worst possible pain) - 1.Prior to mask application, 2. Before speculum insertion, 3. Immediately after speculum insertion, 4. Immediately after insertion of first laminaria, 5. Immediately after insertion of last laminaria, 6. After speculum removal (including actual VAS and recall of maximal VAS during the procedure), 7. Before the D&E the next day.

Satisfaction with the procedure will be collected as well- overall satisfaction (0-100) and satisfaction with pain control (0-100).

Data regarding adverse events will be collected as well.

Primary outcome:

Self-report of pain score immediately following speculum removal.

Secondary outcome:

Self-report of maximal pain during the procedure.

The protocol will not be repeated if a participant is to return for further laminaria insertion.

Study Type

Interventional

Enrollment (Anticipated)

60

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 55 years (ADULT, CHILD)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Informed consent

Exclusion Criteria:

  • D&E due to PPROM or infection.
  • Known N2O allergy.
  • Contraindication to N2O use - Congenital heart defects, pulmonary hypertension, megaloblastic anemia, O2 blood saturation <95%

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: DOUBLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: Study Arm
Patients will receive inhaled N2O/O2 (70% N2O and 30% O2). A sterile bivalve speculum will be placed. Laminaria will be inserted. Inhaled N2O/O2 will be stopped after speculum removal.
Drug: Nitrous oxide (N2O/O2)
Nitrous oxide (N2O/O2) for pain alleviation
PLACEBO_COMPARATOR: Control Arm

Patients will receive inhaled O2 (100% O2). A sterile bivalve speculum will be placed. Laminaria will be inserted. Inhaled O2 will be stopped after speculum removal.

Patients will receive inhaled O2 (100% O2) throughout the procedure until speculum removal.
Drug: Oxygen (O2)
Oxygen (O2) as placebo for control group

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Self-report of change in pain score immediately following speculum removal
Time Frame: 2 days
Pain will be assessed at 7-time intervals using a visual analog pain scale 0 (no pain) to 100 (worst possible pain) - 1.Prior to mask application, 2. Before speculum insertion, 3. Immediately after speculum insertion, 4. Immediately after insertion of first laminaria, 5. Immediately after insertion of last laminaria, 6. After speculum removal (including actual VAS and recall of maximal VAS during the procedure), 7. Before the D&E the next day.
2 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Self-report of change in maximal pain during the procedure
Time Frame: 2 days
Pain will be assessed at 7-time intervals using a visual analog pain scale 0 (no pain) to 100 (worst possible pain) - 1.Prior to mask application, 2. Before speculum insertion, 3. Immediately after speculum insertion, 4. Immediately after insertion of first laminaria, 5. Immediately after insertion of last laminaria, 6. After speculum removal (including actual VAS and recall of maximal VAS during the procedure), 7. Before the D&E the next day.
2 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sheba Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ANTICIPATED)

December 1, 2022

Primary Completion (ANTICIPATED)

June 1, 2024

Study Completion (ANTICIPATED)

December 1, 2024

Study Registration Dates

First Submitted

September 22, 2022

First Submitted That Met QC Criteria

October 11, 2022

First Posted (ACTUAL)

October 13, 2022

Study Record Updates

Last Update Posted (ACTUAL)

October 13, 2022

Last Update Submitted That Met QC Criteria

October 11, 2022

Last Verified

April 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SHEBA-22-8935-ST-CTIL

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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