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Question 22#

You evaluate a 48-year-old man for chronic renal insufficiency. He has a history of hypertension, osteoarthritis, and gout. He currently has no complaints. His medical regimen includes lisinopril 40 mg daily, hydro-chlorothiazide 25 mg daily, allopurinol 300 mg daily, and acetaminophen for his joint pains. He does not smoke but drinks 8 oz of wine on a daily basis. Examination shows BP 146/86, pulse 76, a soft S4 gallop, and mild peripheral edema. There is no abdominal bruit. His UA reveals 1+ proteinuria and no cellular elements. Serum creatinine is 2.2 mg/dL and his estimated GFR from the MDRD formula is 42 mL/minute.

What is the most important element is preventing progression of his renal disease?

A. Discontinuing all alcohol consumption
B. Discontinuing acetaminophen
C. Adding a calcium channel blocker to improve blood pressure control
D. Obtaining a CT renal arteriogram to exclude renal artery stenosis
E. Changing the lisinopril to losartan

Correct Answer is C

Comment:

This patient has stage III chronic kidney disease (estimated GFR 30-60 mL/minute). At this stage it is crucial for the internist to prevent progression to end-stage renal disease. Blood pressure control, with a target blood pressure of less than 130 systolic and less than 80 diastolic, is a critical element in his management. The patient is on maximal doses of thiazide and angiotensin-converting inhibitor (ACEI), so the addition of a calcium channel blocker is appropriate. Other important management issues include avoiding nephrotoxins (such as NSAIDs and IV contrast agents), if possible, modest dietary protein restriction, and atherosclerotic risk factor management. If the patient progresses to stage IV CKD (estimated GFR 15-30 mL/minute), he should be referred to a nephrologist. Modest ethanol consumption is not a renal or cardiovascular risk factor and need not be modified unless you believe the patient is consuming much more alcohol than he admits. Acetaminophen in usual therapeutic doses is the safest agent to control DJD pain and certainly is preferable to nonsteroidals. Angiotensin receptor blockers (such as losartan) can be substituted for ACEIs if side effects such as cough occur, but ARBs have no advantage over ACEIs in preventing progression of CKD. The critical element is tighter blood pressure control.