From the Guidelines
Carbon monoxide poisoning with normal pH and PaO2 levels should still be treated with high-flow oxygen therapy, typically 100% oxygen via a non-rebreather mask, as recommended by the American Journal of Respiratory and Critical Care Medicine 1. This treatment should be initiated immediately and continued until carboxyhemoglobin (COHb) levels fall below 5% and symptoms resolve, usually for 4-6 hours.
- Key considerations in the management of carbon monoxide poisoning include:
- Initiation of high-flow oxygen therapy as soon as possible
- Monitoring of COHb levels and symptoms
- Consideration of hyperbaric oxygen therapy in severe cases or those with neurological symptoms, pregnancy, or COHb levels above 25%
- Additional supportive care, such as cardiac monitoring and IV fluids if needed
- Follow-up neurological assessment to detect potential delayed sequelae Despite normal pH and PaO2 readings, carbon monoxide causes tissue hypoxia by binding to hemoglobin with 200-250 times greater affinity than oxygen, preventing oxygen delivery to tissues.
- The use of standard pulse oximetry can be misleading in CO poisoning, as it cannot distinguish between oxyhemoglobin and carboxyhemoglobin, highlighting the importance of COHb level measurement 1. In some cases, hyperbaric oxygen therapy may be considered, and the optimal dose and frequency of hyperbaric oxygen treatments for acute carbon monoxide poisoning remain unknown, but it is reasonable to retreat persistently symptomatic patients to a maximum of three treatments 1.
- The decision to use hyperbaric oxygen therapy should be made on a case-by-case basis, taking into account the severity of the poisoning, the presence of neurological symptoms, and other individual factors.