26th July 2024

You are the haematology SHO on call and have been asked to review a patient with a raised haematocrit on the ward

You are the haematology SHO on call and have been asked to review a patient with a raised haematocrit on the ward. They are a 75-year-old gentleman with a long history of COPD who has been admitted following a fall. He has no other medical problems, but he has an exercise tolerance of 20 metres due to his COPD. You suspect a secondary polycythaemia. What test could help differentiate if this is a primary or secondary polycythaemia?

Select the SINGLE most appropriate option from the list below. Select ONE option only.