Question

If a patient has persistent activity in the renal pelvis during renography, furosemide administration may:

a. assist in dx of renovascular htn
b. help rule out mechanical obstruction
c. cause a transplant to be rejected
d. decreae the radiation burden on the bladder
e. none of the above

Answer 1

Furosemide, a loop diuretic, helps rule out mechanical obstruction during renography by inhibiting Na+ and Cl- reabsorption, which increases urine production.

Step-by-step explanation:

If a patient has persistent activity in the renal pelvis during renography, furosemide administration may help rule out mechanical obstruction. Furosemide is a loop diuretic that works on the ascending limb of the loop of Henle, inhibiting the reabsorption of Na+ and Cl- ions. As a result of this inhibition, diuretics like furosemide increase urine production because they prevent the reabsorption of these ions, leading to increased excretion of water alongside the ions.

The use of furosemide in renography can assist in differentiating renal obstruction from non-obstructive dilatation. If the radioisotope used in a renogram fails to quickly clear from the renal pelvis post furosemide administration, it suggests mechanical obstruction. However, if the radioisotope clears after furosemide is administered, this indicates that there was no significant obstruction to begin with.

Therefore, the correct answer to the student's question is: Furosemide administration may help rule out mechanical obstruction in the case of persistent activity in the renal pelvis during renography.