A 55-year-old woman is intubated for hypoxaemic respiratory failure. The registrar performs a point-of-care arterial blood gas using a pre-heparinised...

Question

A 55-year-old woman is intubated for hypoxaemic respiratory failure. The registrar performs a point-of-care arterial blood gas using a pre-heparinised syringe. The sample is exposed to air for 3 minutes before analysis. How will air contamination most likely affect the ABG results?

Accepted Answer

Decreased PaCO2 and increased PaO2 (towards atmospheric values: PO2 ~21 kPa, PCO2 ~0.04 kPa)

Answer

Increased PaCO2 and decreased PaO2

Answer

No change in any parameter

Answer

Decreased pH only

Answer

Increased lactate

uk-fficm MCQ (SBA): ABG Pre-Analytical Error

A 55-year-old woman is intubated for hypoxaemic respiratory failure. The registrar performs a point-of-care arterial blood gas using a pre-heparinised syringe. The sample is exposed to air for 3 minutes before analysis. How will air contamination most likely affect the ABG results?