Carbon Monoxide Poisoning

Hyperbaric Oxygen Therapy Approval Status

Yes Clearance by US Food and Drug Administration (FDA)

Yes Approval by the Undersea and Hyperbaric Medical Society (UHMS)

About Clearance and Approval


Definition and Causes

Carbon monoxide (CO) is a highly toxic gas that has no color, no odor, and no taste. When inhaled, carbon monoxide binds to hemoglobin in red blood cells and blocks their capacity to carry oxygen to cells and tissues. Carbon monoxide also causes cellular damage that directly injures blood vessels and the central nervous system.

Carbon monoxide is the most common cause of injury and death by poisoning, both accidental and intentional (suicide). Common sources of CO gas include vehicles, generators, tools, cooking equipment, stoves, or furnaces that burn gasoline, wood, coal, natural gas, propane, oil, kerosene, methane, or other fossil fuels.

Inhaling even small amounts of CO can be fatal. Serious neurological effects may be delayed days or weeks after acute poisoning. Chronic exposure may cause persistent headaches, dizziness, nausea, and permanent neurological damage.

Evidence Index

FDA cleared, widely reimbursed
Strong body of evidence
Repeatedly favorable results
Early or mixed results
Unfavorable or no evidence
Strong evidence against HBOT

Treatment with Hyperbaric Oxygen Therapy

Supplemental oxygen, at normal or hyperbaric pressures, is the primary treatment for carbon monoxide poisoning. Hyperbaric oxygen therapy (HBOT) dissolves additional oxygen in the blood plasma and has been shown to block all known cellular mechanisms of CO toxicity. HBOT is also used to treat smoke inhalation in firefighters and other fire victims who suffer carbon monoxide poisoning complicated by cyanide poisoning.

Read the Carbon Monoxide Poisoning page in the Undersea and Hyperbaric Medical Society resource library to learn more about carbon monoxide poisoning, the rationale for hyperbaric oxygen therapy, and key clinical evidence, outcomes, and success factors. There are restrictions on timeframe during which hyperbaric oxygen should be used for this condition.

HyperbaricLink Commentary

Every year CO poisoning accounts for some 50,000 emergency room visits and kills about 450 Americans by accidental exposure alone. US fire departments respond to seven nonfire CO incidents every hour [ NFPA, 2005 ]. For more than 50 years emergency physicians have been increasing their use of hyperbaric oxygen to treat acute carbon monoxide poisoning, yet access to emergency-ready hyperbaric chambers remains a public health resource deficiency in the United States.

Since 2008 the UHMS has participated in the CDC national surveillance system for carbon monoxide poisoning. Findings from nearly 2,000 cases at 87 hyperbaric facilities in 39 states are just now emerging for careful analysis and publication. These data will make a welcome addition to the medical literature, which currently lacks the strongest evidence, from randomized controlled trials (RCTs), to support the routine use of hyperbaric oxygen for acute CO poisoning. [ Cochrane, 2011 ]

Patient Resources

HyperbaricLink recommends the following websites for anyone seeking authoritative information, patient advocacy, and community support for carbon monoxide poisoning.

American Association of Poison Control Centers (AAPCC)

The AAPCC is a nonprofit organization representing 57 poison centers staffed by pharmacists, physicians, nurses, and toxicology specialists who provide free, private, expert medical advice 24/7/365.

Carbon Monoxide Poisoning
US Centers for Disease Control and Prevention (CDC)

The CDC website provides an excellent section on carbon monoxide prevention, detection, and treatment. Included are tips on preventing CO poisoning when boating and using generators.

National Fire Protection Association (NFPA)

A leading authority on fire, electrical, and building safety, the NFPA provides free PDF downloads with excellent carbon monoxide safety tips and CO detector guidelines.

An Introduction to Indoor Air Quality (IAQ)
US Environmental Protection Agency (EPA)

The EPA website includes a complete and easy-to-read section indoor air quality hazards, including carbon monoxide and other common polutants. The CO section provides helpful tips on selection and placement of carbon monoxide detectors—a must for every home.

Clinical Resources

Start with the following resources to explore current research activities and the peer-reviewed medical literature on hyperbaric oxygen therapy for carbon monoxide poisoning.

 Use the search buttons below to go directly to research on hyperbaric oxygen therapy.

Carbon monoxide surveillance:  routinedisaster
US Centers for Disease Control and Prevention (CDC)

The CDC routine and disaster surveillance programs for carbon monoxide, conducted in conjunction with the Undersea and Hyperbaric Medical Society, are working to provide more data on treatment with hyperbaric oxygen and many other factors. The pages provide links to the latest publications.
US National Institutes of Health keeps the official list of human clinical trials currently enrolling, in progress, and recently completed. One may reasonably question the size and legitimacy of any study not listed here.



An independent, international, nongovernmental organization, the Cochrane Collaboration is a powerful force in evidence-based medicine. One may consider a Cochrane Reviews article on any HBOT topic required hyperbaric reading.

Read the 2011 Cochrane Intervention Review: Hyperbaric oxygen for carbon monoxide poisoning from the Cochrane Injuries Group, doi:10.1002/14651858.CD002041.pub3

Google Scholar

A specialized Google search engine, Google Scholar indexes scholarly articles, patents, and legal opinions and journals. Google Scholar may produce many search results, but entries provide easy access to full-text journal articles.

Search Google Scholar


HBOEvidence uses computerized tools to appraise the key randomized controlled trials (RCTs) in the hyperbaric medical literature. One may reasonably question the overall strength of HBOT evidence for any disease or condition not covered here.

Search HBOEvidence
National Library of Medicine, US National Institutes of Health

PubMed keeps the official list of scientific papers published in reputable peer-reviewed medical journals. One may reasonably question the importance and legitimacy of any study not listed here.



News About Carbon Monoxide Poisoning and Hyperbaric Oxygen Therapy

More news from O2.0 – the HyperbaricLink blog

Complete carbon monoxide news archive from O2.0 — the HyperbaricLink blog

Further Learning

HyperbaricLink suggests The Quiet Killer  from CDC-TV Health Matters, uploaded 12 February 2009.

Related Terms

  • Asphyxiation
  • Cyanide poisoning
  • Emergency medical services (EMS)
  • Emergency medical technician (EMT)
  • Fire
  • Firefighter
  • Paramedic
  • Smoke inhalation
  • Suicide


Undersea and Hyperbaric Medical Society, Indications, Carbon Monoxide Poisoning. Retrieved 02 May 2015.
Carbon monoxide poisoning, Centers for Disease Control and Prevention (CDC). Retrieved 26 November 2011.
Page Data
Updated: 24 Jul 2015 03:50 PM
Created: 13 Jun 2009 12:00 AM
By: About the authors »