Carbon Monoxide Poisoning Symptoms
The most common symptoms of carbon monoxide poisoning include headache, dizziness, nausea/vomiting, confusion, fatigue, chest pain, shortness of breath, and loss of consciousness, though no single symptom is either sensitive or specific. 1
Key Clinical Manifestations
- Headache is the most common symptom, though there is no characteristic headache pattern typical of CO poisoning 1
- Neurological symptoms include dizziness, confusion, and loss of consciousness 1
- Gastrointestinal manifestations include nausea and vomiting 1
- Cardiopulmonary symptoms include chest pain and shortness of breath 1, 2
- Fatigue and general malaise are common presentations 1
- Symptoms are nonspecific and may mimic other conditions such as viral syndromes, food poisoning, or psychiatric disorders 3, 4
Diagnostic Challenges
- No combination of symptoms either confirms or excludes a diagnosis of CO poisoning 1
- Symptoms do not correlate with carboxyhemoglobin (COHb) levels, making clinical assessment challenging 1, 5
- The classic "cherry red" skin coloration is rare and typically only appears with lethal levels of CO poisoning 1
- Even when using specialized measurement techniques on fatal CO poisoning victims, less than half demonstrate "cherry red" skin 1
- A high index of suspicion is warranted, particularly during cold weather, in patients with acute coronary syndrome and arrhythmias 1
Severe Poisoning Manifestations
- Loss of consciousness indicates severe poisoning and is associated with worse outcomes 1, 6
- Cardiovascular complications may include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias 2
- Seizures may occur in severe cases 2
- Metabolic acidosis may be present, especially if exposure occurred during a house fire (which may indicate concomitant cyanide poisoning) 6
Delayed Neurological Sequelae
- Delayed neurological symptoms may appear 2-40 days after apparent recovery from acute poisoning 3
- These can include memory disturbances, personality changes, calculation difficulties, vestibular problems, and motor dysfunction 6, 3
- Parkinsonian features may develop in some cases 3
- Approximately 75% of patients with delayed neurological sequelae recover within 1 year 3
Common Pitfalls
- Failing to consider CO poisoning in patients with nonspecific neurological or flu-like symptoms 5, 7
- Relying on COHb levels alone to rule out CO poisoning when the history and symptoms are consistent with exposure 5
- Waiting for laboratory confirmation before initiating oxygen therapy 6
- Discharging patients without ensuring the CO source has been identified and eliminated 6
- Not scheduling follow-up to assess for delayed neurological sequelae 6, 3