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The Cyclocapnic Method for Measurement of Chemosensitivity

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified January 2010 by Imperial College London.
Recruitment status was:  Recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT01049256
First Posted: January 14, 2010
Last Update Posted: January 14, 2010
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
Imperial College London
January 13, 2010
January 14, 2010
January 14, 2010
January 2008
April 2010   (Final data collection date for primary outcome measure)
Chemoreflex gain as measured by cyclocapnic method [ Time Frame: every minute ]
Same as current
No Changes Posted
Not Provided
Not Provided
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The Cyclocapnic Method for Measurement of Chemosensitivity
Developing an Improved Measure of Chemosensitivity for the Study of Periodic Breathing in Heart Failure: the Cyclocapnic Method

We aim to test our method for measuring chemosensitivity (the ventilatory response to a change in carbon dioxide), which uses sinusoidal carbon dioxide stimuli.

Hypotheses:

  • Carbon dioxide sensitivity is dependent on the cycle time over which we administer the gas (frequency).
  • Chemoreflex gain decreases as deadspace increases.
We will apply a new method for the measurement of chemosensitivity (how sensitive a person is to changes in carbon dioxide), which is one of the principle determinants of whether people with heart failure develop abnormal breathing patterns We have shown in a pilot study that administering sinusoidal patterns of inspired carbon dioxide produces similar sinusoidal responses in ventilation. We aim to test our method for measuring chemosensitivity, which uses sinusoidal carbon dioxide stimuli (similar to those that drive the oscillations in ventilation found in periodic breathing). We aim to show that how the cycle time of carbon dioxide administered affects the resulting ventilatory oscillations and therefore that when measuring the chemoreflex clinically, it is important to deliver carbon dioxide stimuli that replicate the cycle time of oscillations in carbon dioxide seen in periodic breathing (typically approximately one minute).
Interventional
Phase 1
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
  • Periodic Breathing
  • Heart Failure
Other: carbon dioxide
sinusoidal carbon dioxide administration
Not Provided
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Unknown status
45
October 2010
April 2010   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Heart failure subjects with stable cardiorespiratory control to be recruited from our institution's specialist heart failure clinic.
  • Normal healthy volunteers, with normal systolic function.

Exclusion Criteria:

  • We will exclude patients with chronic respiratory disease (every patient will have formal lung function testing on entrance into the study) or unstable coronary artery disease (myocardial infarction or unstable angina within the past 3 months).
  • In addition any subjects receiving treatment with morphine and derivatives, theophylline, oxygen, benzodiazepines or acetazolamide will be excluded as these affect chemosensitivity.
Sexes Eligible for Study: Male
18 Years to 80 Years   (Adult, Senior)
Yes
Contact information is only displayed when the study is recruiting subjects
United Kingdom
 
 
NCT01049256
07/H0712/129
No
Not Provided
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Darrel Francis, Imperial College
Imperial College London
Not Provided
Principal Investigator: Darrel P Francis, MD Imperial College London
Imperial College London
January 2010

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP