Jestoni with chronic renal failure (CRF) is admitted to the urology unit. The nurse is aware that the diagnostic test is consistent with CRF if the result is:
A. Increased pH with decreased hydrogen ions.
B. Increased serum levels of potassium, magnesium, and calcium.
C. Blood urea nitrogen (BUN) 100 mg/dl and serum creatinine 6.5 mg/ dl.
D. Uric acid analysis 3.5 mg/dl and phenolsulfonphthalein (PSP) excretion 75%.
Correct Answer: C. Blood urea nitrogen (BUN) 100 mg/dl and serum creatinine 6.5 mg/dl.
The normal BUN level ranges 8 to 23 mg/dl; the normal serum creatinine level ranges from 0.7 to 1.5 mg/dl. The test results in option C are abnormally elevated, reflecting CRF and the kidneys’ decreased ability to remove nonprotein nitrogen waste from the blood.
Option A: CRF causes decreased pH and increased hydrogen ions — not vice versa.
Option B: CRF also increases serum levels of potassium, magnesium, and phosphorus, and decreases serum levels of calcium.
Option D: A uric acid analysis of 3.5 mg/dl falls within the normal range of 2.7 to 7.7 mg/dl; PSP excretion of 75% also falls with the normal range of 60% to 75%.