question-7 - medicine_king

[ArchivalUser]

med-king, please help explain: If the pt had RAS, how to explain her normal Na+ and K+?
Thank you.

[ArchivalUser]

I think the reason is unilateral vs bilateral. Unilateral stenosis still has the other side working so electrolyte abnormality wont be seen

[ArchivalUser]

correct..pl read explanation and then if have any questions post..i know yr question ans is in the expla so didnt answer..

[ArchivalUser]

can anyone explain the reason of headache here?

[ArchivalUser]

Thank you, 2nd time for the clear explanation.

However, I have a second opinion:

first of all: The stenosis must have caused an increase in renin-angio-aldosterone no matter it is unilateral or bilateral. Therefore, even though BUN/Cr is normal, Na+ and K+ most likely not normal.

second: The answer said captopril renography is because they regard renal stenosis as the most common cause of secondary HTN. However, renal parenchymal disease is the most common cause of secondary HTN.

In summary, MRI will identify the parenchymal disease which is both the most common cause of HTN and with normal electrolytes. this can also explain the headache.

I still go with MRI.