Carbon Monoxide Poisoning
Description General measures Medicine treatment ICD-10 code: Y17 DESCRIPTION Poisoning caused by accidental or intentional exposure to fires in poorly ventilated areas, combustion engines, faulty stoves and faulty heating systems. Patients present with: dizziness, headache, seizures and other CNS symptoms, nausea and vomiting, chest pain, tachycardia, high arterial carboxyhaemoglobin
Description
General measures
Medicine treatment
ICD-10 code: Y17
DESCRIPTION
Poisoning caused by accidental or intentional exposure to fires in poorly ventilated areas, combustion engines, faulty stoves and faulty heating systems.
Patients present with:
- dizziness,
- headache,
- seizures and other CNS symptoms,
- nausea and vomiting,
- chest pain,
- tachycardia,
- high arterial carboxyhaemoglobin levels,
- impaired level of consciousness,
- retinal haemorrhages,
- respiratory alkalosis (mild),
- metabolic acidosis (severe).
Note:
There may be a normal arterial PaO2, but low oxygen saturation on pulse oximetry. Neither are useful in assessing severity of carbon monoxide poisoning. Ideally, a blood gas sample should be sent for co-oximetry to specifically detect carboxyhaemoglobin levels.
GENERAL MEASURES
- Remove patient from toxic environment.
- Ventilation may be needed in deeply comatosed patients.
- Monitor ECG and neurological status.
MEDICINE TREATMENT
- Give 100% oxygen via positive pressure facemask.
- Evidence for the benefit of hyperbaric oxygen therapy is unclear, therefore, it cannot be routinely advised.
For seizures:
- Benzodiazepines. See: The Nervous System, Status epilepticus (convulsive).
Note:
Phenytoin should be avoided (due to potential cardiotoxicity).
Metabolic acidosis:
Metabolic acidosis shifts the oxygen-dissociation curve to the right and, therefore, aids in maintaining tissue oxygenation despite reduced haemoglobin carrying capacity. Metabolic acidosis should only be treated if profound and persistent, following standard treatment protocols.
Patients should be followed up after discharge for the persistence of neurocognitive symptoms.
In patients not responding to 100% oxygen, consider exposure to cyanide during the fire and refer patient urgently.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Paediatrics, 2023 Edition
Chapter 18: Poisoning, 18.1 Poisoning, 18.1.21 Carbon Monoxide Poisoning