Carbon Monoxide Poisoning

Pitfalls in the Clinical Diagnosis of CO Poisoning:

Clinical signs and symptoms do not always match COHb levels

Cherry red color of skin, lips and nail beds, usually considered to be classical sign, is not consistently present. There may also be cyanosis due to respiratory depression

Some symptoms are aggravated by pre-existing disease, such as intermittent claudication

Tachypnea is frequently absent because the carotid body is responsive to PO₂, not arterial blood oxygen content

CO poisoning is frequently misdiagnosed as:

--- Migraine headache

--- Stroke

--- Psychiatric illness

--- Food poisoning

--- Acute ethanol intoxication or delerium tremens

--- Heart disease

Misdiagnoses in CO Poisoning

Barret Study of Misdiagnosis