From the Guidelines
The primary treatment for exhaust fumes (carbon monoxide) inhalation is immediate removal from the source of exposure and administration of 100% oxygen therapy, with consideration of hyperbaric oxygen therapy in severe cases, particularly for patients with loss of consciousness, neurological symptoms, cardiac involvement, or carboxyhemoglobin levels above 25% 1.
Key Considerations
- Patients should be taken to fresh air and given high-flow oxygen through a non-rebreather mask until their carboxyhemoglobin levels normalize (typically below 5%) 1.
- Hyperbaric oxygen therapy may be necessary in severe cases, which involves breathing pure oxygen in a pressurized chamber to rapidly reduce carbon monoxide levels in the blood 1.
- Supportive care including intravenous fluids, cardiac monitoring, and management of any complications like seizures or acidosis may also be required.
- The goal of hyperbaric treatment is the prevention of long-term and permanent neurocognitive dysfunction, not enhancement of short-term survival rates 1.
Special Populations
- Pregnant women and young children are at risk for permanent sequelae of CO poisoning, and adult treatment criteria are generally applied to these patients 1.
- In pregnancy, fetal distress and fetal death are special concerns in CO poisoning, and hyperbaric oxygen therapy has been administered safely to pregnant women, but there are no prospective studies of efficacy 1.
Treatment Decisions
- Treatment decisions in the mildly poisoned patient are difficult and the subject of controversy, even among experts in the field 1.
- The presence of the APOE e4 allele may be associated with worse outcome after brain injury, and patients with this allele may not derive benefit from hyperbaric oxygen treatment 1.
- Hyperbaric oxygen therapy should not be withheld because a CO-poisoned individual is doing well clinically and appears not likely to die from the event 1.
From the Research
Treatment for Exhaust Fumes (Carbon Monoxide) Inhalation
The treatment for carbon monoxide poisoning, which can occur due to exhaust fumes inhalation, primarily involves hyperbaric oxygen therapy and supportive care. Key aspects of treatment include:
- Hyperbaric oxygen therapy: This is considered the most effective treatment for acute carbon monoxide poisoning, especially for minimizing delayed neurological sequelae 2.
- Normobaric oxygen: While normobaric oxygen can be used, hyperbaric oxygen is preferred due to its greater benefits in improving energy metabolism, preventing lipid peroxidation, and decreasing neutrophil adherence in the brain 2.
- Patient selection: Criteria for hyperbaric treatment include neurological deficit, episodes of depressed consciousness, cardiovascular disturbance, and minor symptoms unresponsive to oxygen 3.
- Treatment outcomes: Studies have shown improved outcomes with hyperbaric oxygen therapy compared to normobaric oxygen, including lower hospital mortality and incidence of severe short-term memory loss 4.
Hyperbaric Oxygen Therapy
Hyperbaric oxygen therapy is administered in a hyperbaric chamber where the patient breathes pure oxygen at higher-than-atmospheric pressures. This treatment:
- Enhances the displacement of carbon monoxide from hemoglobin, thereby restoring oxygen delivery to tissues 5.
- Reduces the risk of delayed neurological sequelae, which can occur in approximately 10% of patients with carbon monoxide poisoning 5.
- Should be considered for any patient who has suffered an interval of unconsciousness, regardless of their clinical exam on arrival 5.
Supportive Care
In addition to hyperbaric oxygen therapy, supportive care is crucial and may include:
- Mechanical ventilation for patients with severe respiratory depression 3, 4.
- Full haemodynamic monitoring for patients with cardiovascular instability 3.
- Intravenous sedation for patients requiring it 3.
- Monitoring for cerebral oedema and consideration of intracranial pressure monitoring and CT scans of the head in severely poisoned patients 4.