EndoscopyPhase 4NCT05396144
Can Nitrous Oxide (Laughing Gas) be Used as a Sedative for GI Endoscopy Procedures?
A Phase 4 study testing 5% inhaled nitrous oxide and 50% inhaled nitrous oxide in people with Endoscopy and Colonoscopy, run by Stanford University at 1 site in United States.
Trial summary
Nitrous oxide (commonly known as 'laughing gas') is often used during dental and other outpatient procedures, because it is easy to administer, is short-acting and rapidly clears from the body following the procedure. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Endoscopy, Colonoscopy
- What is being tested?
- 5% inhaled nitrous oxide and 50% inhaled nitrous oxide
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 0 participants
- Where
- 1 siteUnited States
- Study dates
- 1 May 2024to 31 Aug 2025
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Non-pregnant patients age 18 and older
- Patient's presenting for upper endoscopy or colonoscopy under endoscopist- directed nurse sedation.
- Patient is willing and able to consent and comply with study procedures.
Who cannot join
- Age <18
- Potentially vulnerable subjects including, homeless people, pregnant females, employees and students.
- Participation in another investigational study that may directly or indirectly affect the results of this study within 30 days prior to the initial visit
- Allergy to the proposed anesthetic agents (e.g. nitrous oxide, midazolam, fentanyl, diphenhydramine)
Trial locations and contacts
1 site in 1 country.
United States1 site
Stanford University Hospital
Stanford, California, 94305
About this study
Official title: Evaluation of Nitrous Oxide Use in GI Endoscopy Procedures: Potential for Optimizing Sedation and Minimizing Side-Effects During Recovery
Nitrous oxide (commonly known as 'laughing gas') is often used during dental and other outpatient procedures, because it is easy to administer, is short-acting and rapidly clears from the body following the procedure.
The investigators hypothesize that use of Nitrous oxide during GI endoscopy may enhance patient comfort during the procedure and speed-up post-procedure recovery, while minimizing the fatigue and mental fogginess some patients report the day after receiving standard sedative and narcotic drugs used routinely for the procedure.
The investigators are interested in determining if adding Nitrous Oxide to commonly used sedation drugs will decrease fatigue, mental fogginess, and nausea/vomiting, as well as determine when the patient felt fully recovered from the effects of all sedatives given for the procedure.
- Conditions
- Endoscopy, Colonoscopy
- Being tested
- 5% inhaled nitrous oxide, 50% inhaled nitrous oxide
- Keywords
- sedative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
5% inhaled nitrous oxideDrug
5% Nitrous oxide will be administered by face or nasal mask to be inhaled by the patient
50% inhaled nitrous oxideDrug
50% Nitrous oxide will be administered by face or nasal mask to be inhaled by the patient
| Study group | Role | What they receive |
|---|---|---|
| 5% inhaled nitrous oxide | Sham comparator | Patients will received 5% nitrous oxide by face mask in addition to standard intravenous sedatives given at the discretion of the care provider. Receives: Drug: 5% inhaled nitrous oxide |
| 50% inhaled nitrous oxide | Active comparator | Patients will received 50% nitrous oxide by face mask in addition to standard intravenous sedatives given at the discretion of the care provider. Receives: Drug: 50% inhaled nitrous oxide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Intravenous sedative drug
Tabulate the types and dosages of intravenous sedative drugs given
Measured: Duration of the procedure (1-2 hours)
Recovery time
Time spent in procedure room to recover
Measured: Duration of the procedure (1-3hours)
Patient comfort
Patient comfort rating intra-procedure using standardized scale
Measured: Duration of the procedure (1-3hours)
Fatigue
The number of patients who experienced fatigue
Measured: 24-36 hours
Fatigue
The duration of fatigue experienced, if any
Measured: 24-36 hours
Nausea/vomiting
Number of patients who experienced nausea/vomiting
Measured: 24-36 hours
Nausea/vomiting
Duration of nausea/vomiting
Measured: 24-36 hours
Mental Fogginess post-procedure/sedation
Duration of mental fogginess following the procedure/sedation
Measured: 24-36 hours
Mental Fogginess post-procedure/sedation
Number of patients who experienced mental fogginess post-procedure/sedation
Measured: 24-36 hours
Return to baseline function
Number of hours post-procedure/sedation for patient to return to baseline function
Measured: 24-36 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2022
- Study start1 May 2024
- Primary completion31 Aug 2025 (estimated)
- Study completion31 Aug 2025 (estimated)
Why it stopped: We do not have access to the patient population anymore due to a move in our operational design
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for EndoscopyStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- 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 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Patients will be randomized to either receive 5% or 50% inhaled nitrous oxide in addition to typical sedative agents which will be given at the direction of the doctor performing the procedure. There is a 50% chance you will be assigned to receive either 5% or 50% nitrous oxide
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tim Angelotti, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05396144
- Sponsor's protocol ID
- 54961
- Status last verified
- Mar 2026
- First submitted
- 12 May 2022
- Last updated
- 27 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Nitrous Oxide Use in GI Endoscopy Procedures: Potential for Optimizing Sedation and Minimizing Side-Effects During Recovery
- ClinicalTrials.gov ID
- NCT05396144
- Acronym / sponsor ID
- 54961
- Conditions
- Endoscopy, Colonoscopy
- Keywords
- sedative
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: We do not have access to the patient population anymore due to a move in our operational design
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- 1 May 2024 (actual)
- Primary completion
- 31 Aug 2025 (estimated)
- Study completion
- 31 Aug 2025 (estimated)
- First posted
- 31 May 2022 (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.
Nitrous oxide (commonly known as 'laughing gas') is often used during dental and other outpatient procedures, because it is easy to administer, is short-acting and rapidly clears from the body following the procedure.
The investigators hypothesize that use of Nitrous oxide during GI endoscopy may enhance patient comfort during the procedure and speed-up post-procedure recovery, while minimizing the fatigue and mental fogginess some patients report the day after receiving standard sedative and narcotic drugs used routinely for the procedure.
The investigators are interested in determining if adding Nitrous Oxide to commonly used sedation drugs will decrease fatigue, mental fogginess, and nausea/vomiting, as well as determine when the patient felt fully recovered from the effects of all sedatives given for the procedure.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
- Model description
- Patients will be randomized to either receive 5% or 50% inhaled nitrous oxide in addition to typical sedative agents which will be given at the direction of the doctor performing the procedure. There is a 50% chance you will be assigned to receive either 5% or 50% nitrous oxide
| Arm | Type | Receives |
|---|---|---|
| 5% inhaled nitrous oxide | Sham comparator | Drug: 5% inhaled nitrous oxidePatients will received 5% nitrous oxide by face mask in addition to standard intravenous sedatives given at the discretion of the care provider. |
| 50% inhaled nitrous oxide | Active comparator | Drug: 50% inhaled nitrous oxidePatients will received 50% nitrous oxide by face mask in addition to standard intravenous sedatives given at the discretion of the care provider. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Non-pregnant patients age 18 and older
- Patient's presenting for upper endoscopy or colonoscopy under endoscopist- directed nurse sedation.
- Patient is willing and able to consent and comply with study procedures.
Key exclusion criteria (4 listed)
- Age <18
- Potentially vulnerable subjects including, homeless people, pregnant females, employees and students.
- Participation in another investigational study that may directly or indirectly affect the results of this study within 30 days prior to the initial visit
- Allergy to the proposed anesthetic agents (e.g. nitrous oxide, midazolam, fentanyl, diphenhydramine)
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 |
|---|---|---|
| 5% inhaled nitrous oxide5% Nitrous oxide will be administered by face or nasal mask to be inhaled by the patient | Drug | 5% inhaled nitrous oxide |
| 50% inhaled nitrous oxide50% Nitrous oxide will be administered by face or nasal mask to be inhaled by the patient | Drug | 50% inhaled nitrous oxide |
Primary outcome
Intravenous sedative drug
Time frame: Duration of the procedure (1-2 hours)
Tabulate the types and dosages of intravenous sedative drugs given
Recovery time
Time frame: Duration of the procedure (1-3hours)
Time spent in procedure room to recover
Patient comfort
Time frame: Duration of the procedure (1-3hours)
Patient comfort rating intra-procedure using standardized scale
Fatigue
Time frame: 24-36 hours
The number of patients who experienced fatigue
Fatigue
Time frame: 24-36 hours
The duration of fatigue experienced, if any
Nausea/vomiting
Time frame: 24-36 hours
Number of patients who experienced nausea/vomiting
Nausea/vomiting
Time frame: 24-36 hours
Duration of nausea/vomiting
Mental Fogginess post-procedure/sedation
Time frame: 24-36 hours
Duration of mental fogginess following the procedure/sedation
Mental Fogginess post-procedure/sedation
Time frame: 24-36 hours
Number of patients who experienced mental fogginess post-procedure/sedation
Return to baseline function
Time frame: 24-36 hours
Number of hours post-procedure/sedation for patient to return to baseline function
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2026.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing 5% inhaled nitrous oxide and 50% inhaled nitrous oxide in people with Endoscopy and Colonoscopy, run by Stanford University at 1 site in United States.
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 3 inclusion and 4 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: withdrawn, as of the sponsor's last update on 27 Mar 2026. 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 United States. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
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?
Intravenous sedative drug (time frame: Duration of the procedure (1-2 hours)). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 27 Mar 2026.