A physician is treating a patient exhibiting symptoms of impaired renal function following a massive hemorrhage.The physician orders a serum sodium and a PAH clearance test.The patient has a serum PAH of 1.0 mg/dL,urine PAH of 200 mg/dL,and a urine volume of 240 mL in 2 hours.The serum sodium is decreased.
-Based on the information provided,would it be better for this patient to have an increased or decreased serum renin level?

Question

Quizplus · Accepted Answer

PAH (para-aminohippuric acid) is used as a marker to measure renal blood flow. The PAH clearance test helps to determine the glomerular filtration rate (GFR). In this case, the urine PAH level is much higher than the serum PAH level, indicating that there is a significant amount of PAH that is filtered by the kidneys. A decreased serum sodium level suggests that there may be low blood volume or pressure, which can stimulate the renin-angiotensin-aldosterone system (RAAS) to increase renin secretion. Increasing the serum renin level can stimulate the production of angiotensin II, which can increase blood pressure, increase sodium absorption in the kidney, and increase potassium excretion. Therefore, an increased serum renin level may help to improve renal function in this patient.

A Physician Is Treating a Patient Exhibiting Symptoms of Impaired