GlaucomaPhase 4NCT00967694
Effect of Nitrous Oxide (N2O) on Intraocular Pressure in Healthy Volunteers
A Phase 4 study testing Nitrous oxide in people with Glaucoma and Sedation, run by Oregon Health and Science University at 1 site in United States.
Trial summary
The purpose of this study is to learn if breathing nitrous oxide (also known as "laughing gas") changes the pressure in a person's eyes. Some patients who need regular eye exams to measure their eye pressure often need to be put to sleep with medicine in order to complete the eye exam. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- What is being tested?
- Nitrous oxide
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2009to Oct 2011
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Adults aged 18-40
- American Society of Anesthesiologists Physical Classification System (ASA) Status 1-2
- Nil per os (NPO) prior to study (2 hrs clear liquids, 4 hrs milk, 6 hrs light food, 8 hrs heavy/greasy food)
Who cannot join
- Lack of volunteer consent
- Pregnancy
- History of features suggestive of a difficult airway on pre-anesthetic evaluation and physical examination
- Active gastroesophageal reflux disease
- Active obstructive sleep apnea
- History of recent trauma
Show all 15Show fewer
- History of pneumothorax or lung cyst
- History of Vitamin B12 deficiency
- History of recent middle ear surgery (<3months)
- Current or recent (<3 weeks) respiratory tract infection
- Any acute illness or exacerbation of chronic illness such as asthma, chronic lung disease etc.
- Any history of cardiac ischemia (angina), myocardial infarction, or cardiac dysrhythmia.
- Myopia greater than -3 spherical equivalents or hyperopia greater than +3 spherical equivalents
- History of eye surgery of any sort, including refractive surgery, cataracts, and vitrectomy
- History of any ocular disease or infection
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of N2O on Intraocular Pressure in Healthy Volunteers
The purpose of this study is to learn if breathing nitrous oxide (also known as "laughing gas") changes the pressure in a person's eyes. Some patients who need regular eye exams to measure their eye pressure often need to be put to sleep with medicine in order to complete the eye exam. Some of these medicines are known to cause changes in a person's eye pressure. Because of this, such medicines are avoided if the eye doctor needs to measure the patient's eye pressure. One medicine that is frequently used to put patients to sleep is nitrous oxide. No one really knows what effect nitrous oxide might have on a persons' eye pressure. The investigators are interested to see if nitrous oxide causes an increase, decrease, or no change in eye pressure. The investigators also want to investigate if there is a difference in the effects of nitrous oxide on eye pressure between males and females. Understanding these effects of nitrous oxide is important because during such eye exams, the eye doctor uses the pressure measurements to make important decisions about treatment and surgery options for the patient.
The investigators hypothesize that the use of inhaled nitrous oxide (N2O) will result in a decrease in IOP in healthy volunteers.
The investigators aim to determine the magnitude and duration of change, if any, in IOP caused by inhalation of N2O, and to assess if the gender of the patient has a role in this effect.
Read the detailed description
An initial pre-anesthetic evaluation and physical examination will be performed by an attending anesthesiologist, and an eye exam will be performed by an attending ophthalmologist to determine suitability for inclusion according to the above criteria. Ideally the eye exam will take place immediately prior to conduction of the study. However, logistical restraints may require that the eye exam take place at a separate time/date prior to conduction of the study. IOPs will be measured by the attending ophthalmologist (B.E.) who will be blinded to the actual readings of the Tonopen by means of a small screen, and a single trained observer (E.F.) will record observations from the Tonopen. The nitrous oxide sedation will be managed by the attending anesthesiologist (K.L.). All patients will be monitored throughout using standardized monitoring (continuous EKG, non-invasive BP, and continuous pulse oximetry).
- Being tested
- Nitrous oxide
- Keywords
- Glaucoma, Nitrous oxide
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nitrous oxideDrug
Also called N2O
Nitrous oxide sedation by inhalation
| Study group | Role | What they receive |
|---|---|---|
| Nitrous oxide administration | Experimental | All 20 healthy volunteers had their intraocular pressure (IOP) measured at baseline and then after 3, 6, 9, and 12 minutes of nitrous oxide administration, and then after 5, 10, and 15 minutes of breathing room air. There was therefore only one study arm, with each individual serving as their control for baseline and then intervention values of IOP measurement. Receives: Drug: Nitrous oxide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Intraocular Pressure During Nitrous Oxide Sedation
Measured: Before, during and after administration of nitrous oxide (45 minutes total)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Aug 2009 (estimated)
- Study startAug 2009
- Primary completionOct 2011
- Study completionOct 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for GlaucomaStudies of the same condition, open and under way.
- More trials run by Oregon Health and Science 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Oregon Health and Science University
- Sponsor type
- University, hospital or other
- Collaborators
- Robert L. Bacon Medical Foundation, Research to Prevent Blindness
- Responsible party
- Principal investigator, Kirk Lalwani, Oregon Health and Science University
- Investigators
- Kirk Lalwani, MD,FRCA,MCR, Principal investigator, Oregon Health and Science University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00967694
- Sponsor's protocol ID
- IRB00005402
- Status last verified
- Sep 2014
- First submitted
- 27 Aug 2009
- Last updated
- 23 Sep 2014
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of N2O on Intraocular Pressure in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT00967694
- Acronym / sponsor ID
- IRB00005402
- Keywords
- Glaucoma, Nitrous oxide
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Oregon Health and Science UniversityUniversity, hospital or other
- Collaborators
- Robert L. Bacon Medical Foundation, Research to Prevent Blindness
- Study start
- Aug 2009
- Primary completion
- Oct 2011 (actual)
- Study completion
- Oct 2011 (actual)
- First posted
- 28 Aug 2009 (estimated)
- Results
- Posted 23 Sep 2014
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to learn if breathing nitrous oxide (also known as "laughing gas") changes the pressure in a person's eyes. Some patients who need regular eye exams to measure their eye pressure often need to be put to sleep with medicine in order to complete the eye exam. Some of these medicines are known to cause changes in a person's eye pressure. Because of this, such medicines are avoided if the eye doctor needs to measure the patient's eye pressure. One medicine that is frequently used to put patients to sleep is nitrous oxide. No one really knows what effect nitrous oxide might have on a persons' eye pressure. The investigators are interested to see if nitrous oxide causes an increase, decrease, or no change in eye pressure. The investigators also want to investigate if there is a difference in the effects of nitrous oxide on eye pressure between males and females. Understanding these effects of nitrous oxide is important because during such eye exams, the eye doctor uses the pressure measurements to make important decisions about treatment and surgery options for the patient.
The investigators hypothesize that the use of inhaled nitrous oxide (N2O) will result in a decrease in IOP in healthy volunteers.
The investigators aim to determine the magnitude and duration of change, if any, in IOP caused by inhalation of N2O, and to assess if the gender of the patient has a role in this effect.
Detailed description
An initial pre-anesthetic evaluation and physical examination will be performed by an attending anesthesiologist, and an eye exam will be performed by an attending ophthalmologist to determine suitability for inclusion according to the above criteria. Ideally the eye exam will take place immediately prior to conduction of the study. However, logistical restraints may require that the eye exam take place at a separate time/date prior to conduction of the study. IOPs will be measured by the attending ophthalmologist (B.E.) who will be blinded to the actual readings of the Tonopen by means of a small screen, and a single trained observer (E.F.) will record observations from the Tonopen. The nitrous oxide sedation will be managed by the attending anesthesiologist (K.L.). All patients will be monitored throughout using standardized monitoring (continuous EKG, non-invasive BP, and continuous pulse oximetry).
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- Single blind (investigator)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Nitrous oxide administration | Experimental | Drug: Nitrous oxideAll 20 healthy volunteers had their intraocular pressure (IOP) measured at baseline and then after 3, 6, 9, and 12 minutes of nitrous oxide administration, and then after 5, 10, and 15 minutes of breathing room air. There was therefore only one study arm, with each individual serving as their control for baseline and then intervention values of IOP measurement. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Adults aged 18-40
- American Society of Anesthesiologists Physical Classification System (ASA) Status 1-2
- Nil per os (NPO) prior to study (2 hrs clear liquids, 4 hrs milk, 6 hrs light food, 8 hrs heavy/greasy food)
Key exclusion criteria (15 listed)
- Lack of volunteer consent
- Pregnancy
- History of features suggestive of a difficult airway on pre-anesthetic evaluation and physical examination
- Active gastroesophageal reflux disease
- Active obstructive sleep apnea
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 |
|---|---|---|
| Nitrous oxideAlso: N2ONitrous oxide sedation by inhalation | Drug | Nitrous oxide administration |
Primary outcome
Change in Intraocular Pressure During Nitrous Oxide Sedation
Time frame: Before, during and after administration of nitrous oxide (45 minutes total)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2014.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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.
Kirk Lalwani, MD,FRCA,MCR principal investigator
Oregon Health and Science University
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 Nitrous oxide in people with Glaucoma and Sedation, run by Oregon Health and Science 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 15 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: finished, as of the sponsor's last update on 23 Sep 2014. 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. 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?
Yes. Results are posted in the registry (first posted 23 Sep 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Change in Intraocular Pressure During Nitrous Oxide Sedation (time frame: Before, during and after administration of nitrous oxide (45 minutes total)). 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 23 Sep 2014.