Management of Declining Renal Function with Elevated BUN and Creatinine

Immediate Assessment and Stabilization

The American College of Cardiology recommends administering isotonic crystalloid if hypovolemia is present, and monitoring response with serial BUN, creatinine, and electrolytes 1
Consider NT-proBNP if heart failure is suspected, as cardiac dysfunction commonly coexists with renal insufficiency 1
Stop or reduce nephrotoxic medications, including NSAIDs, which should be avoided during acute renal dysfunction, as recommended by the American Heart Association 2

Recheck blood chemistry 1-2 weeks after any medication adjustment, and monitor BUN, creatinine, and electrolytes frequently during diuretic therapy 1
Some rise in BUN and creatinine is expected after ACE inhibitor initiation; if the increase is small and asymptomatic, no action is necessary, according to the American College of Cardiology 1

If serum creatinine increases to more than 3 mg/dL, renal insufficiency severely limits drug efficacy and enhances toxicity, as stated by the Journal of the American College of Cardiology 3
In patients with serum creatinine greater than 5 mg/dL, hemofiltration or dialysis may be needed to control fluid retention and allow tolerance of standard heart failure medications, as recommended by the American Heart Association 3
Small or moderate elevations of BUN and serum creatinine should not lead to minimizing therapy intensity, provided renal function stabilizes, according to the American Heart Association 4

Do not initiate ACE inhibitors or beta blockers in patients with systolic blood pressure less than 80 mmHg or signs of peripheral hypoperfusion, as recommended by the American Heart Association 4
Patients with renal hypoperfusion show impaired response to ACE inhibitors and are at increased risk of adverse effects, according to the Journal of the American College of Cardiology 3

If edema becomes resistant to treatment despite aggressive diuresis, ultrafiltration or hemofiltration may be needed to achieve adequate fluid control and restore responsiveness to conventional loop diuretic doses, as recommended by the American Heart Association 4
Use diuretics cautiously with close monitoring of renal function if heart failure is suspected, according to the American College of Cardiology 1

Virtually all medications require dose adjustment based on estimated creatinine clearance using the Cockcroft-Gault formula, not the MDRD formula, as stated by the American Heart Association 5
Medications should be dosed based on renal function according to their package inserts, according to the Infectious Diseases Society of America 6

Certain medications may elevate serum creatinine without affecting actual renal function, such as cobicistat, dolutegravir, and trimethoprim, as noted by the Infectious Diseases Society of America 6