Carbon Monoxide Monitoring and Emergency Treatment (COMET)

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. Identifier: NCT00841165
Recruitment Status : Unknown
Verified April 2010 by University of Vermont.
Recruitment status was:  Recruiting
First Posted : February 11, 2009
Last Update Posted : April 2, 2010
Information provided by:
University of Vermont

February 10, 2009
February 11, 2009
April 2, 2010
January 2009
June 2010   (Final data collection date for primary outcome measure)
Half life of Carboxyhemoglobin [ Time Frame: Every 15 minutes during treatment ]
Same as current
Complete list of historical versions of study NCT00841165 on Archive Site
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Carbon Monoxide Monitoring and Emergency Treatment
Randomized Trial of Carbon Monoxide Elimination Kinetics With Oxygen Delivered by Continuous Positive Airway Pressure Compared to Face Mask
Carbon monoxide (CO) has been called a "silent killer", and those patients who survive CO poisoning are at risk of neurological damage, which may be permanent. CO is a leading cause of unintentional poisoning deaths in the United States, and the odorless gas results in an estimated average of 20,636 emergency department (ED) visits each year. Oxygen is the antidote for CO poisoning, and it acts both by attenuating toxic effects and enhancing elimination. A fractional inspired concentration of oxygen (FiO2) of 0.7 to 0.9 may be achieved by administration of 100% oxygen delivered using a reservoir with a facemask that prevents rebreathing. Hyperbaric oxygen therapy may provide added benefit for patients with CO poisoning, but this therapy is unavailable in many parts of the United States including Vermont. Use of a continuous positive airway pressure (CPAP) mask may achieve an FiO2 of 1.0, but the effects of delivering an FiO2 of 1.0 compared to 0.7 in CO poisoning are unknown. CPAP, by comparison, is inexpensive, portable, and available in most EDs. In this study, the investigators are testing the hypothesis that oxygen delivered by CPAP will improve both CO washout kinetics and functional outcomes, compared to the standard therapy of oxygen delivered by non-rebreathing facemask. Specific Aim 1 will provide toxicokinetic data to support a potential benefit in the use of CPAP for CO poisoning, by comparing CO elimination kinetics in response to oxygen therapy delivered by non-rebreathing facemask versus CPAP. The 20 patients expected in our first year will provide adequate power to detect a 20% fall in half-time of CO elimination. While CPAP may increase CO washout rates, as predicted in Specific Aim 1, demonstration of real functional benefit will be tested in Specific Aim 2. This Aim seeks to determine functional (neuropsychological) outcomes in patients with CO poisoning treated with oxygen therapy delivered by non-rebreathing facemask versus CPAP. Data showing a therapeutic benefit from CPAP in CO poisoning would have clinical implications. Compared to hyperbaric oxygen therapy, CPAP therapy can begin earlier, including the pre-hospital setting, for patients with known exposure. With the frequent nature of CO poisoning and the widespread availability of CPAP, a potential benefit could lead to improved outcomes for the 20,000+ patients who present to EDs annually.
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Not Applicable
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Carbon Monoxide Poisoning
  • Device: Continuous Positive Airway Pressure
    Full face CPAP at 5cm H2O and 100% oxygen
  • Device: Non-rebreather oxygen mask
    Oxygen administered through a non-rebreather mask
  • Experimental: 1
    Participants in this arm are treated with Continuous Positive Airway Pressure at 5cm H2O and 100% oxygen
    Intervention: Device: Continuous Positive Airway Pressure
  • Active Comparator: 2
    Participants in this arm receive standard of care therapy- oxygen via a non-rebreather mask
    Intervention: Device: Non-rebreather oxygen mask

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Unknown status
Same as current
June 2010
June 2010   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Elevated Carboxyhemoglobin Level (non-smokers >8%, smokers >12%)
  • 18 years of age or older
  • Able to provide informed consent as assessed by Attending Emergency Physician

Exclusion Criteria:

  • Requires daily medication for active lung disease
  • Altered mental status
  • Hemodynamically unstable
  • Requires transfer to ICU or hyperbaric oxygen facility
  • Previous enrollment in the study
  • No concurrent acute psychiatric illness
Sexes Eligible for Study: All
18 Years and older   (Adult, Older Adult)
Contact information is only displayed when the study is recruiting subjects
United States
CHRMS 09-056
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Dr. Kalev Freeman, Faculty Sponsor, Department of Surgery, University of Vermont
University of Vermont
Not Provided
Study Director: Kalev Freeman, MD, PhD University of Vermont
University of Vermont
April 2010

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