A 58-year-old male is found unresponsive following a house fire. He has soot around his nose and mouth, singed nasal hairs, and hoarseness. His SpO2 r...

Question

A 58-year-old male is found unresponsive following a house fire. He has soot around his nose and mouth, singed nasal hairs, and hoarseness. His SpO2 reads 99% on a pulse oximeter. Why might the pulse oximeter reading be unreliable in this scenario?

Accepted Answer

Carbon monoxide binds to haemoglobin and is read as oxyhaemoglobin by standard pulse oximeters

Answer

High ambient light from the fire scene affects the reading

Answer

The patient is peripherally vasoconstricted from hypothermia

Answer

The patient likely has methaemoglobinaemia

Answer

Soot on the finger probe interferes with light absorption

uk-dipimc MCQ (SBA): Carbon Monoxide Poisoning

A 58-year-old male is found unresponsive following a house fire. He has soot around his nose and mouth, singed nasal hairs, and hoarseness. His SpO2 reads 99% on a pulse oximeter. Why might the pulse oximeter reading be unreliable in this scenario?