Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Dynamic Carbon Dioxide (CO2) Administration for Sleep Apnoea

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:  Not yet recruiting
Imperial College Healthcare NHS Trust
Information provided by:
Imperial College London Identifier:
First received: January 4, 2010
Last updated: NA
Last verified: January 2010
History: No changes posted

Normally breathing is controlled by a reflex that responds to the levels of carbon dioxide (CO2) in the blood. In heart failure, where the heart muscle is damaged and therefore does not pump as well, this reflex is exaggerated. The result is a vicious circle: blood CO2 levels fluctuate wildly and as a result breathing also fluctuates with patients hyperventilating at times and briefly stopping breathing at others. During sleep this is called central sleep apnoea (CSA).

Patients with CSA wake up throughout the night and whilst some patients are oblivious to this, others are consciously breathless and many patients are tired during the day and feel unable to perform their daily activities.

As part of the body's stress response to the erratic pattern of breathing, both blood pressure and heart rate may rise to a level that is harmful in a failing heart, exacerbating the underlying heart failure. Indeed patients who demonstrate this CSA die sooner than those who have heart failure and stable breathing.

There are no proven specific therapies for CSA that stabilise breathing, improve sleep quality, and prolong life. We have designed a system which delivers very small doses of CO2, when the blood level of CO2 is predicted to be low. During short daytime recordings, using this system, we have demonstrated that it is possible to stabilise the body's CO2 levels.

We aim to test what happens when CO2 is given overnight whilst the patient is sleeping to see whether we can stabilise their breathing over longer durations and whether sleep quality could be improved so that patients are less tired during the day. In addition, we would like to measure whether the stress response is lessened if the breathing is successfully stabilised.

Condition Intervention Phase
Sleep Apnea, Central
Other: Carbon dioxide
Phase 2

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
Official Title: Dynamic Carbon Dioxide Administration for Central Sleep Apnoea in Heart Failure

Resource links provided by NLM:

Further study details as provided by Imperial College London:

Primary Outcome Measures:
  • Extent of respiratory instability [ Time Frame: over 8 hours ]
  • Arousals [ Time Frame: over 8 hours ]

Secondary Outcome Measures:
  • End-tidal CO2 [ Time Frame: per breath ]
  • 24 hour urinary catecholamines [ Time Frame: per 24 hours ]
  • Mean heart rate [ Time Frame: per 1 s ]
  • Number of ectopic heart beats [ Time Frame: per 8 hours ]
  • Mean blood pressure [ Time Frame: every 9 hours ]
  • Mean Ventilation [ Time Frame: every 1 second ]

Estimated Enrollment: 24
Study Start Date: February 2010
Estimated Study Completion Date: October 2010
Estimated Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Intervention Details:
    Other: Carbon dioxide
    2% inhaled CO2 for up to 8 hours.
    Other: Carbon dioxide
    Up to a maximum of 2% CO2, only delivered for a maximum of up to 20 seconds per 60 seconds for 8 hours

Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Men and women 18 to 79 years of age who have New York Heart Association (NYHA) functional class I through IV heart failure due to ischemic, hypertensive, or idiopathic dilated cardiomyopathy and whose condition had been stabilized by means of optimal medical therapy for at least one month;
  • An LVEF of less than 40% and central sleep apnea, defined as 15 or more episodes of apnea and hypopnea per hour of sleep, more than 50 percent of which are determined to be central rather than obstructive.

Exclusion Criteria:

  • Pregnancy,
  • Myocardial infarction,
  • Unstable angina or cardiac surgery within the previous three months.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01041924

Foundation G. Monasterio
Pisa, Italy, 56124
United Kingdom
Imperial NHS Trust
London, United Kingdom, W21NY
Sponsors and Collaborators
Imperial College London
Imperial College Healthcare NHS Trust
Principal Investigator: Darrel P Francis, MD Imperial College London
  More Information

Additional Information:
Responsible Party: Dr Darrel P Francis, Imperial College Identifier: NCT01041924     History of Changes
Other Study ID Numbers: FS/04/079
Study First Received: January 4, 2010
Last Updated: January 4, 2010

Keywords provided by Imperial College London:
Sleep apnea
Periodic breathing
Heart Failure

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Central
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on April 28, 2017