Carbon Monoxide Poisoning

Key Features

• Degree of toxicity correlates well with the carboxyhemoglobin level taken soon after acute exposure but not after oxygen has been given or when there has been some time since exposure

• Outcome of severe poisoning may be complete recovery, vegetative state, or any degree of mental injury between these extremes

• Primary mental deficits are neuropsychiatric

Clinical Findings

• Onset of symptoms may be more rapid and more severe if the patient lives at a high altitude, has a high respiratory rate (ie, infants), is pregnant, or has myocardial insufficiency or lung disease

• Presents with such nonspecific symptoms as headache or flu-like illness

• Confusion, unsteadiness, and coma may occur

Diagnosis

• Proteinuria, glycosuria, elevated serum aminotransferase levels, or ECG changes may be present in the acute phase

• Permanent cardiac, liver, renal, or CNS damage occurs occasionally

Treatment

• 100% oxygen should be administered immediately

• Hyperbaric oxygen therapy at 2.0–2.5 atm of oxygen shortens the half-life to 30 minutes

• Use of hyperbaric oxygen therapy for delayed neurologic sequelae can be considered, but remains controversial

• After the level has been reduced to near zero, therapy is aimed at the nonspecific sequelae of anoxia

• Evaluation of the source should be performed before the patient returns to the home