The Silent Killer: Carbon Monoxide

Centers for Disease Control and Prevention National Center for Environmental Health Division of Environment Hazards and Health Effects Air Pollution and Respiratory Health Branch


February 08, 2013

Editorial Collaboration

Medscape &

In This Article

Management of Confirmed or Suspected CO Poisoning

Administer 100% oxygen until the patient is symptom-free, usually about 4-5 hours. Serial neurologic examinations should be performed to assess progress and to detect the signs of developing cerebral edema.

Consider hyperbaric oxygen (HBO) therapy in the patient whose COHb level is higher than 25%- 30%, in whom there is evidence of cardiac involvement, severe acidosis, transient or prolonged unconsciousness, neurologic impairment, abnormal neuropsychiatric testing, or who is ≥ 36 years of age. HBO is also administered at lower COHb levels (< 25%) if suggested by the clinical condition and/history of exposure.

HBO is the treatment of choice for pregnant women, even if they are less severely poisoned. HBO is safe to administer, and international consensus favors it as part of a more aggressive role in treating pregnant women.

Long-term Considerations of CO Poisoning

Cardiac injury during CO poisoning increases risk for mortality during the 10 years following poisoning, so in patients with severe CO poisoning, it may be important to perform an ECG and measurement of troponin and cardiac enzymes. Chest radiography is also recommended for seriously poisoned patients, especially those with loss of consciousness or cardiopulmonary signs and symptoms.In addition, brain CT or MRI is recommended in these cases; these tests may show signs of cerebral infarction secondary to hypoxia or ischemia.

All discharged patients should be warned of possible delayed neurologic complications and given instructions on what to do if these occur. Follow-up should include a repeat medical and neurologic examination in 2 weeks. Babies and infants, the elderly, and people with chronic heart disease, anemia, or respiratory illness are at increased risk for complications from CO exposure. In addition, all women of childbearing age who are suspected of having CO poisoning should have a pregnancy test.

Measures for Preventing CO Poisoning

Patients should be advised to install and maintain a battery-operated or battery back-up CO detector in their homes if any of the following sources of CO poisoning are in use:

Home heating systems (fuel-burning furnaces)

Motor vehicles

Power washers and other gas-powered tools.

Generators, grills, camp stoves, or other gasoline, propane, natural gas, or charcoal-burning devices should never be used inside a home, basement, garage, or camper -- or even outside when less than 20 feet from a window, door, or vent.

Editor's Note: CDC offers accredited Web-on-demand Carbon Monoxide Poisoning Prevention Clinical Education

Web Resources

CDC Carbon Monoxide Poisoning

CDC Clinical Guidance for Carbon Monoxide Poisoning After a Disaster