Management of Elevated Creatinine

Initial Assessment

The American College of Cardiology recommends comparing current creatinine to baseline values from the previous 3 months to establish if the elevation is acute or chronic 1, 2
Acute kidney injury (AKI) is defined as an increase in serum creatinine by ≥0.3 mg/dL within 48 hours, OR increase to ≥1.5 times baseline within 7 days 1
Calculate the rate of creatinine change to assess progression velocity 1

Discontinue all nephrotoxic medications immediately: NSAIDs, aminoglycosides, vancomycin, amphotericin B, and certain chemotherapy agents 1, 2
Temporarily hold ACE inhibitors/ARBs if AKI is present with volume depletion, but do not discontinue for minor increases ≤30% from baseline in stable patients 1, 3, 4, 5, 6, 7

Order a complete metabolic panel including electrolytes, BUN, creatinine, calcium, and phosphate 1
Urinalysis with microscopy to look for casts, cells, crystals, and protein 1
Urine albumin-to-creatinine ratio (UACR) to quantify proteinuria 1, 3, 4, 5, 6

For Stage 1 AKI: Discontinue nephrotoxic agents and ensure adequate volume status and perfusion pressure 1
For Stage 2-3 AKI: Consider ICU admission for close monitoring and initiate renal replacement therapy if necessary 1
Target systolic blood pressure <120 mmHg using standardized office measurement 8
Use ACE inhibitor or ARB as first-line therapy for patients with hypertension and proteinuria, uptitrating to maximally tolerated dose 5, 6, 8

Monitor daily creatinine and electrolytes until stabilized, then weekly during acute management phase 1, 2
Monitor both albuminuria and eGFR at least annually, more frequently if eGFR <60 mL/min/1.73 m² 1, 3, 4, 5, 6

Refer promptly to nephrology for eGFR <30 mL/min/1.73 m² 1, 4, 6
Refer promptly to nephrology for uncertainty about the etiology of kidney disease 1, 2, 4, 6
Refer promptly to nephrology for rapidly progressing kidney disease (>50% increase in creatinine over short period) 1, 4, 6, 7

Do not mistake physiological causes for pathological kidney disease: High muscle mass, recent vigorous exercise, dehydration, and high protein diet can transiently elevate creatinine 7
Do not confuse medication effects with true kidney injury: Trimethoprim and cimetidine reduce tubular secretion of creatinine without causing actual renal dysfunction 7
Do not underdose ACE inhibitors/ARBs due to fear of creatinine rise, as clinical benefit requires maximally tolerated doses 7
Counsel patients to hold ACE inhibitors/ARBs and diuretics during sick days when at risk for volume depletion 8