A 50-year-old woman on ICU has a pulmonary artery catheter. The measured SvO2 is 78%. Cardiac index is 4.5 L/min/m2, Hb 95 g/L, PaO2 13 kPa, lactate 4...

Question

A 50-year-old woman on ICU has a pulmonary artery catheter. The measured SvO2 is 78%. Cardiac index is 4.5 L/min/m2, Hb 95 g/L, PaO2 13 kPa, lactate 4.2 mmol/L. What does the elevated SvO2 with elevated lactate suggest?

Accepted Answer

Both B and D are possible explanations

Answer

Adequate oxygen delivery with no tissue hypoxia

Answer

Distributive shock with microcirculatory shunting - tissues are unable to extract oxygen despite adequate global delivery, or oxygen is being shunted past capillary beds

Answer

Carbon monoxide poisoning

Answer

Cyanide poisoning - inhibition of cytochrome oxidase prevents cellular oxygen utilisation

uk-fficm MCQ (SBA): High SvO2 with Elevated Lactate

A 50-year-old woman on ICU has a pulmonary artery catheter. The measured SvO2 is 78%. Cardiac index is 4.5 L/min/m2, Hb 95 g/L, PaO2 13 kPa, lactate 4.2 mmol/L. What does the elevated SvO2 with elevated lactate suggest?