HypercapniaNCT01782625
Hypercapnia: Cognitive Effects and Monitoring
A study testing NO exercise at depth and exercise at depth in people with Hypercapnia and Exercise, run by Duke University at 1 site in United States.
Trial summary
The investigators will simulate the conditions of a working, helmeted diver by using exercising, "head out" immersed subjects to test the following hypotheses: 1. An algorithm can be developed which predicts cognitive performance in immersed exercising divers, based on the exhaled carbon dioxide (PETCO2) and the… Read more about this study
- Who is it for?
- Ages 18 to 50 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Hypercapnia, Exercise, Nitrogen Narcosis
- What is being tested?
- NO exercise at depth and exercise at depth
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 58 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2013to Feb 2016
- Phase
- Interventional
- 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 to 50 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- healthy,
- male,
- age greater than 18,
- age less than 50
Who cannot join
- smoker,
- asthma,
- cardiac disease,
- inability to pedal a bicycle ergometer,
- inability to perform vigorous exercise
Trial locations and contacts
1 site in 1 country.
United States1 site
Duke Center for Hyperbaric Medicine and Environmental Physiology
Durham, North Carolina, 27710
About this study
The investigators will simulate the conditions of a working, helmeted diver by using exercising, "head out" immersed subjects to test the following hypotheses:
- An algorithm can be developed which predicts cognitive performance in immersed exercising divers, based on the exhaled carbon dioxide (PETCO2) and the diver's inspired partial pressures of oxygen and nitrogen (PIO2 and PIN2).
- PETCO2 using mass spectrometry is an accurate estimate of arterial carbon dioxide (PaCO2) at rest and during immersed exercise and can be used as a PaCO2 surrogate at levels exceeding 50 mmHg and depths up to 158 fsw (gas density 6.4 g/l, similar to 165 fsw density of 6.8 g/l).
- Conditions
- Hypercapnia, Exercise, Nitrogen Narcosis, Diving, Immersion
- Being tested
- NO exercise at depth, exercise at depth
- Keywords
- diving, cognitive impairment, nitrogen narcosis, narcosis, end tidal carbon dioxide, arterial carbon dioxide, immersion
- Medical subject headings
- Hypercapnia, Motor Activity, Inert Gas Narcosis, Cognitive Dysfunction, Stupor
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NO exercise at depthOther
Subjects will NOT exercise while at depth
exercise at depthOther
Subjects will exercise while at depth
| Study group | Role | What they receive |
|---|---|---|
| dive to 122 feet, no exercise | Experimental | Subjects will undergo a simulated dive to a maximum depth of 122 feet of seawater with no exercise at depth Receives: Other: NO exercise at depth |
| dive to 158 feet, no exercise | Experimental | Subjects will undergo a simulated dive to a maximum depth of 154 feet of seawater with no exercise at depth Receives: Other: NO exercise at depth |
| dive to 122 feet, exercise | Experimental | Subjects will undergo a simulated dive to a maximum depth of 122 feet of seawater with exercise at depth Receives: Other: exercise at depth |
| dive to 158 feet, exercise | Experimental | Subjects will undergo a simulated dive to a maximum depth of 154 feet of seawater with exercise at depth. Receives: Other: exercise at depth |
What is being measured
The primary outcome is the main question the study is designed to answer.
Is cognitive ability different while resting versus compared to cognitive ability while diving, breathing different gas mixtures and while exercising?
Subjects will undergo computerized cognitive testing before, during and after a simulated dive in the Duke Hyperbaric Chamber. Different exercise conditions (rest or exercise) and different breathing gas mixtures (added carbon dioxide or not)will be assessed and compared to the pre-dive conditions.
Measured: pre-dive to dive to post-dive (approximately 2 hours)
Secondary outcomes (1)
How does exhaled (end tidal) carbon dioxide compare with arterial carbon dioxide?
Exhaled (end tidal) carbon dioxide will be compared to arterial carbon dioxide at the various experimental conditions of the study (at the surface versus during the dive, during exercise versus during rest, breathing gas with added carbon dioxide versus breathing gas without added carbon dioxide)
Measured: pre-dive to dive to post dive (approximately 2 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Feb 2013 (estimated)
- Study startJan 2013
- Primary completionFeb 2016
- Study completionFeb 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypercapniaStudies of the same condition, open and under way.
- More trials run by Duke 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 58 participants (actual)
Sponsor and investigators
- Lead sponsor
- Duke University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- John J Freiberger, MD, Principal investigator, Duke University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01782625
- Sponsor's protocol ID
- Pro00036937
- Other IDs
- SPS 181258
- Status last verified
- May 2016
- First submitted
- 31 Jan 2013
- Last updated
- 25 May 2016
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 May 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hypercapnia: Cognitive Effects and Monitoring
- ClinicalTrials.gov ID
- NCT01782625
- Acronym / sponsor ID
- Pro00036937
- Conditions
- Hypercapnia, Exercise, Nitrogen Narcosis, Diving, Immersion
- Keywords
- diving, cognitive impairment, nitrogen narcosis, narcosis, end tidal carbon dioxide, arterial carbon dioxide, immersion
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 58 participants (actual)
- Lead sponsor
- Duke UniversityUniversity, hospital or other
- Study start
- Jan 2013
- Primary completion
- Feb 2016 (actual)
- Study completion
- Feb 2016 (actual)
- First posted
- 4 Feb 2013 (estimated)
- 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 investigators will simulate the conditions of a working, helmeted diver by using exercising, "head out" immersed subjects to test the following hypotheses:
- An algorithm can be developed which predicts cognitive performance in immersed exercising divers, based on the exhaled carbon dioxide (PETCO2) and the diver's inspired partial pressures of oxygen and nitrogen (PIO2 and PIN2).
- PETCO2 using mass spectrometry is an accurate estimate of arterial carbon dioxide (PaCO2) at rest and during immersed exercise and can be used as a PaCO2 surrogate at levels exceeding 50 mmHg and depths up to 158 fsw (gas density 6.4 g/l, similar to 165 fsw density of 6.8 g/l).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| dive to 122 feet, no exercise | Experimental | Other: NO exercise at depthSubjects will undergo a simulated dive to a maximum depth of 122 feet of seawater with no exercise at depth |
| dive to 158 feet, no exercise | Experimental | Other: NO exercise at depthSubjects will undergo a simulated dive to a maximum depth of 154 feet of seawater with no exercise at depth |
| dive to 122 feet, exercise | Experimental | Other: exercise at depthSubjects will undergo a simulated dive to a maximum depth of 122 feet of seawater with exercise at depth |
| dive to 158 feet, exercise | Experimental | Other: exercise at depthSubjects will undergo a simulated dive to a maximum depth of 154 feet of seawater with exercise at depth. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- healthy,
- male,
- age greater than 18,
- age less than 50
Key exclusion criteria (5 listed)
- smoker,
- asthma,
- cardiac disease,
- inability to pedal a bicycle ergometer,
- inability to perform vigorous exercise
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 |
|---|---|---|
| NO exercise at depthSubjects will NOT exercise while at depth | Other | dive to 122 feet, no exercise, dive to 158 feet, no exercise |
| exercise at depthSubjects will exercise while at depth | Other | dive to 122 feet, exercise, dive to 158 feet, exercise |
Primary outcome
Is cognitive ability different while resting versus compared to cognitive ability while diving, breathing different gas mixtures and while exercising?
Time frame: pre-dive to dive to post-dive (approximately 2 hours)
Subjects will undergo computerized cognitive testing before, during and after a simulated dive in the Duke Hyperbaric Chamber. Different exercise conditions (rest or exercise) and different breathing gas mixtures (added carbon dioxide or not)will be assessed and compared to the pre-dive conditions.
1 secondary outcome
How does exhaled (end tidal) carbon dioxide compare with arterial carbon dioxide?
Time frame: pre-dive to dive to post dive (approximately 2 hours)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 May 2016.
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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.
John J Freiberger, MD principal investigator
Duke University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing NO exercise at depth and exercise at depth in people with Hypercapnia and Exercise, run by Duke 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 4 inclusion and 5 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 25 May 2016. 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.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Is cognitive ability different while resting versus compared to cognitive ability while diving, breathing different gas mixtures and while exercising? (time frame: pre-dive to dive to post-dive (approximately 2 hours)). 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 25 May 2016.