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HealthyNCT00001845

Study of Brain Blood Flow During Induced Hypercapnia (Excess Blood Carbon Dioxide)

An observational study of Healthy and Hypercapnia, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study will evaluate magnetic resonance imaging (MRI ) methods for measuring changes in the brain's blood flow during hypercapnia (a condition of excess carbon dioxide in the blood). MRI is a diagnostic tool that uses a large magnet and radio waves to produce images of the body without X-rays. Read more about this study

Who is it for?
Any ageHealthy volunteers can take part
Conditions the study is for
Healthy, Hypercapnia
How many people
30 participants
Where
1 siteUnited States
Study dates
Sep 1999to Aug 2004
Phase
Observational
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 Any age
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Who may be able to join

  • Any normal volunteer above the age of 18 years old who is capable of giving informed consent.

Who cannot join

  • Subjects will be excluded if they have contraindications to MR scanning, such as the following: aneurism clip, implanted neural stimulator, implanted cardiac pacemaker or autodefibrillator, chochlear implant, ocular foreign body (e.g., metal shavings), or insulin pump. Also, subjects will be excluded if they have panic disorder or migrane (because of possible complications with CO2 inhilation), or if they have cirrhosis, are on high dose aspirin therapy, or have an allergy to acetazolamide injection). Subjects will be excluded if they have allergies to sulfonamide drugs or if they have a chronic respiratory illness.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Warren G. Magnuson Clinical Center (CC)

    Bethesda, Maryland, 20892

Other trials in United States

About this study

Official title: MR Perfusion Imaging in Hypercapnia: Development of Technical Protocols

This study will evaluate magnetic resonance imaging (MRI ) methods for measuring changes in the brain's blood flow during hypercapnia (a condition of excess carbon dioxide in the blood). MRI is a diagnostic tool that uses a large magnet and radio waves to produce images of the body without X-rays.

Healthy normal volunteers in this study may have as many as six MRI scans over a 2-year period. For this procedure, the person lies on a stretcher placed in a strong magnetic field produced by the MRI machine. During the scan, the person's blood carbon dioxide (CO2 ) levels will be increased either by: 1) breathing air mixtures containing up to 5% CO2; or 2) receiving an intravenous (I.V.) injection of a drug called acetazolamide.

Read more

Persons who breathe CO2 will have their heart rate, blood pressure and oxygen levels monitored throughout the procedure. Those receiving acetazolamide will have the drug injected intravenously (I.V.) into an arm vein. If the volunteer experiences any unpleasant side effects from the CO2 or acetazolamide, the study will be stopped.

The information gained from this study will be used to develop better ways to study brain function, possibly leading to better diagnostic and treatment methods.

Read the detailed description

Advances in MR perfusion imaging have provided clinical researchers with the opportunity to quantitate regional increases in cerebral blood flow. The purpose of this study is to acquire the technical experience required to perform MR perfusion imaging studies of the hypercapnic cerebral blood flow response. Cerebral blood flow will be increased by inhalation of carbogen (an air mixture containing 5% CO2) or IV injection of the carbonic anhydrase inhibitor acetazolamide. The technical experience obtained in this study will be used to design a study of the pharmacological and physiological mechanisms underlying cerebral blood flow increases during hypercapnia.

Conditions
Healthy, Hypercapnia
Keywords
MRI, Cerebral Blood Flow, CO2 Inhalation, Acetazolamide, Perfusion, Healthy Volunteer
Medical subject headings
Hypercapnia

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Nov 1999 (estimated)
  2. Study startSep 1999
  3. Study completionAug 2004

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Enrolment
30 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00001845
Sponsor's protocol ID
990164
Other IDs
99-CC-0164
Status last verified
Aug 2004
First submitted
3 Nov 1999
Last updated
4 Mar 2008
Results posted
No

Publications

  • Brian JE Jr. Carbon dioxide and the cerebral circulation. Anesthesiology. 1998 May;88(5):1365-86. doi: 10.1097/00000542-199805000-00029. No abstract available.

    PubMed 9605698
  • Olesen J, Paulson OB, Lassen NA. Regional cerebral blood flow in man determined by the initial slope of the clearance of intra-arterially injected 133Xe. Stroke. 1971 Nov-Dec;2(6):519-40. doi: 10.1161/01.str.2.6.519. No abstract available.

    PubMed 5164581
  • Hauge A, Thoresen M, Walloe L. Changes in cerebral blood flow during hyperventilation and CO2-breathing measured transcutaneously in humans by a bidirectional, pulsed, ultrasound Doppler blood velocitymeter. Acta Physiol Scand. 1980 Oct;110(2):167-73. doi: 10.1111/j.1748-1716.1980.tb06647.x.

    PubMed 6782831

Questions about this trial

What is this clinical trial studying?

An observational study of Healthy and Hypercapnia, run by National Institutes of Health Clinical Center (CC) 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 1 inclusion and 1 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 4 Mar 2008. 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.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00001845, 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 4 Mar 2008.

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