MEDizzy - After receiving a kidney transplant, a patient has severe

Feed Library Learning Discuss Leaderboard Journal

The Body Fluids and Kidneys (I)

After receiving a kidney transplant, a patient has severe hypertension (170/110 mm Hg). A renal arteriogram indicates severe renal artery stenosis in his single remaining kidney, with a reduction in glomerular filtration rate (GFR) to 25% of normal. Which of the following changes, compared with normal, would be expected in this patient, assuming steady-state conditions?

ExplanationSevere renal artery stenosis that reduces GFR to 25% of normal would also decrease renal blood flow but would cause only a transient decrease in urinary creatinine excretion. The transient decrease in creatinine excretion would increase serum creatinine (to about four times normal), which would restore the filtered creatinine load to normal and therefore return urinary creatinine excretion to normal levels under steady-state conditions. Urinary sodium secretion would also decrease transiently but would be restored to normal so that intake and excretion of sodium are balanced. Plasma sodium concentration would not change significantly because it is carefully regulated by the ADH–thirst mechanism.