From the Guidelines
The primary treatment for carbon monoxide poisoning is immediate administration of 100% oxygen therapy, and for severe cases, hyperbaric oxygen therapy (HBOT) may be indicated, especially for patients with loss of consciousness, neurological symptoms, cardiac involvement, or carboxyhemoglobin levels above 25% (or >15% in pregnant women). Patients should be removed from the source of exposure and given high-flow oxygen through a non-rebreather mask or endotracheal tube until their carboxyhemoglobin levels fall below 5% and symptoms resolve, typically for 4-6 hours. HBOT involves breathing 100% oxygen in a pressurized chamber at 2-3 atmospheres for 90-120 minutes, which accelerates carbon monoxide elimination and reduces tissue hypoxia. Supportive care includes cardiac monitoring, intravenous fluids, and management of complications like metabolic acidosis.
Key Considerations
- Carbon monoxide poisoning requires urgent treatment because the gas binds to hemoglobin with 200-250 times greater affinity than oxygen, forming carboxyhemoglobin which prevents oxygen transport and causes tissue hypoxia 1.
- Additionally, carbon monoxide disrupts mitochondrial function and triggers inflammatory cascades that can lead to delayed neurological sequelae, making prompt treatment essential for preventing long-term complications 1.
- The European Committee of Hyperbaric Medicine (ECHM) recommends HBOT for patients with CO poisoning who have a high risk of medium or long-term neurological sequelae, regardless of their carboxyhaemoglobin level at admission 1.
Treatment Recommendations
- Administer 100% oxygen therapy immediately, and consider HBOT for severe cases, especially those with loss of consciousness, neurological symptoms, cardiac involvement, or high carboxyhemoglobin levels 1.
- Provide supportive care, including cardiac monitoring, intravenous fluids, and management of complications like metabolic acidosis 1.
- Consider the patient's individual factors, such as severity of poisoning, stability, and presence of specialized teams, when deciding on HBOT 1.
From the Research
Treatment Overview
The treatment for carbon monoxide (CO) poisoning focuses on the rapid elimination of CO and management of hypoxia.
- Oxygen is the cornerstone of therapy, usually applied via a reservoir face mask 2, 3, 4, 5.
- Hyperbaric oxygen therapy (HBOT) can eliminate CO faster, but its use is controversial and requires extensive equipment and expertise 2, 3, 4, 5.
Treatment Options
- Non-invasive continuous positive airway pressure (CPAP) ventilation using a tight mask can provide a higher inspired fraction of oxygen (FiO2) and increase gas exchange, potentially representing a supplemental approach to current treatment of CO poisoning 2.
- Hyperbaric phototherapy may also augment blood carbon monoxide removal, providing a potential alternative treatment option 6.
- Aggressive supportive measures, such as removal from the source of exposure, are also crucial in treating CO poisoning 4, 5.
Indications for Hyperbaric Oxygen Therapy
- HBOT is often indicated in patients who are comatose or neurologically abnormal, have a history of loss of consciousness with their exposure, or have cardiac dysfunction 3, 5.
- Pregnancy with an elevated CO-Hgb level (>15%-20%) is also widely considered an indication for HBOT 5.
- HBOT may be considered in patients who have persistent symptoms despite normobaric oxygen, metabolic acidosis, abnormalities on neuropsychometric testing, or significantly elevated CO levels 3, 5.