Carbon Monoxide Poisoning

Exam Cram

• Causes: central heating leaks, incomplete combustion from open fires

• Carbon monoxide has a greater affinity to haemoglobin than oxygen, prevention

Background

Carbon monoxide has a greater affinity to haemoglobin than oxygen. This prevents oxygen from binding to haemoglobin and being delivered to the tissues. 

The pulse oximeter cannot differentiate between CO-haemoglobin and Oxygen- haemoglobin, so the saturation probe will read as normal. ABG show hypoxia. 

Causes: 

• Central heating leaks, 

• Incomplete combustion from open fires

Presentation

• Drowsiness

• Headaches

Investigations

• ABG findings:  Metabolic acidosis with hypoxia or normal PO2

• Four wavelength spectrophotometry: showed severe hypoxia

Diagnosis

• Significantly elevated CO on blood gas (venous or arterial)

• Smoking can cause a mild CO rise on ABG - this can be used to detect if an individual is still smoking

Management

• High flow oxygen

• Supportive measures

Written in 2024