Carbon Monoxide Poisoning

Description

General measures

Medicine treatment

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T58 + (X47.99/X67.99/Y17.99)

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
• impaired level of consciousness
• headache
• tachycardia
• seizures and other CNS symptoms
• chest pains
• nausea and vomiting
• retinal haemorrhages
• metabolic acidosis (severe)
• respiratory alkalosis (mild)
• high arterial carboxyhaemoglobin level 

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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.

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GENERAL MEASURES

• Remove patient from toxic environment.
• Ventilation may be needed in deeply comatose patients.
• Monitor ECG and neurological status.

MEDICINE TREATMENT

• Oxygen, 100%, via positive pressure facemask.

For seizures: R56.8 + (T58/X47.99/X67.99/Y17.99)

Treat with benzodiazepines - see Status epilepticus.

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Note:
Phenytoin should be avoided (due to potential cardiotoxicity).  

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LoE:IVb^lxxiii

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.

Click here to access the pdf.

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Standard Treatment Guidelines and Essential Medicines List for South Africa, Adult Hospital Level, 2020-2024_Version 2.0_27 March 2025

Chapter 19 Poisoning_19.20 Carbon Monoxide Poisoning