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Carbon Monoxide Monitoring and Emergency Treatment (COMET)

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 April 2010 by University of Vermont.
Recruitment status was:  Recruiting
Information provided by:
University of Vermont Identifier:
First received: February 10, 2009
Last updated: April 1, 2010
Last verified: April 2010
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.

Condition Intervention
Carbon Monoxide Poisoning
Device: Continuous Positive Airway Pressure
Device: Non-rebreather oxygen mask

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Randomized Trial of Carbon Monoxide Elimination Kinetics With Oxygen Delivered by Continuous Positive Airway Pressure Compared to Face Mask

Resource links provided by NLM:

Further study details as provided by University of Vermont:

Primary Outcome Measures:
  • Half life of Carboxyhemoglobin [ Time Frame: Every 15 minutes during treatment ]

Estimated Enrollment: 40
Study Start Date: January 2009
Estimated Study Completion Date: June 2010
Estimated Primary Completion Date: June 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Participants in this arm are treated with Continuous Positive Airway Pressure at 5cm H2O and 100% oxygen
Device: Continuous Positive Airway Pressure
Full face CPAP at 5cm H2O and 100% oxygen
Active Comparator: 2
Participants in this arm receive standard of care therapy- oxygen via a non-rebreather mask
Device: Non-rebreather oxygen mask
Oxygen administered through a non-rebreather mask


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

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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00841165

Contact: Tyler J Lemay, BFA
Contact: Kalev Freeman, MD PhD

United States, Vermont
Fletcher Allen Health Care Recruiting
Burlington, Vermont, United States, 05401
Principal Investigator: Tyler J Lemay, BFA         
Sponsors and Collaborators
University of Vermont
Study Director: Kalev Freeman, MD, PhD University of Vermont
  More Information

Responsible Party: Dr. Kalev Freeman, Faculty Sponsor, Department of Surgery, University of Vermont Identifier: NCT00841165     History of Changes
Other Study ID Numbers: CHRMS 09-056
Study First Received: February 10, 2009
Last Updated: April 1, 2010

Keywords provided by University of Vermont:
Carbon Monoxide Toxicity

Additional relevant MeSH terms:
Carbon Monoxide Poisoning
Chemically-Induced Disorders
Gas Poisoning
Carbon Monoxide
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Physiological Effects of Drugs processed this record on April 28, 2017