What is the appropriate management for a 55-year-old man with chronic kidney disease stage 3 and a serum creatinine of 1.72 mg/dL?

Management of CKD Stage 3 in a 55-Year-Old Male with Creatinine 1.72 mg/dL

This patient requires blood pressure control to <130/80 mmHg using an ACE inhibitor or ARB, assessment for albuminuria to guide therapy intensity, and nephrology referral if proteinuria exceeds 300 mg/day or eGFR declines rapidly. 1, 2

Initial Assessment and Staging

• Calculate eGFR using the CKD-EPI equation rather than relying on serum creatinine alone, as a creatinine of 1.72 mg/dL can represent significantly reduced kidney function, particularly in patients with lower muscle mass 1, 3
• Stage 3 CKD is subdivided into 3A (eGFR 45-59) and 3B (eGFR 30-44 mL/min/1.73m²), which determines management intensity 1
• Measure urine albumin-to-creatinine ratio (UACR) on a random spot urine collection, as albuminuria level directly influences treatment decisions and cardiovascular risk 1
• Obtain two of three UACR measurements over 3-6 months to confirm persistent albuminuria, given biological variability exceeding 20% 1

Blood Pressure Management

Target blood pressure should be <130/80 mmHg for all patients with CKD stage 3, based on SPRINT trial evidence showing cardiovascular and mortality benefits at this lower target. 1, 2

• Initiate an ACE inhibitor as first-line therapy if UACR ≥300 mg/g (or ≥30 mg/g in the presence of diabetes), as this slows kidney disease progression 1, 4
• Use an ARB only if ACE inhibitor is not tolerated due to cough or angioedema 1, 4
• Never combine an ACE inhibitor with an ARB, as dual RAS blockade increases risks of hyperkalemia and acute kidney injury without additional benefit 1, 4
• Titrate ACE inhibitor or ARB to maximum approved doses to achieve proven renoprotective benefits demonstrated in clinical trials 4
• Accept creatinine increases up to 30% after starting ACE inhibitor/ARB, as this reflects hemodynamic changes from reduced intraglomerular pressure rather than kidney injury 4, 5

Common Pitfall: Excessive Blood Pressure Lowering

• Avoid targeting systolic BP <120 mmHg if diastolic BP drops below 70 mmHg, as this may compromise coronary and kidney perfusion, particularly problematic in patients with low cardiac output 2

Proteinuria Assessment and Additional Therapy

• If UACR ≥200 mg/g, add an SGLT2 inhibitor (if eGFR ≥20 mL/min/1.73m²) for additional renoprotective benefits beyond ACE inhibition 4
• SGLT2 inhibitors provide benefit even in non-diabetic patients with significant albuminuria 4
• If hyperkalemia develops during ACE inhibitor/ARB therapy, implement potassium-lowering measures (dietary restriction, potassium binders) rather than discontinuing the medication 4

Anemia Screening and Management

• Check hemoglobin if eGFR <60 mL/min/1.73m², as anemia develops early in CKD and is undertreated 6
• Diagnose anemia when hemoglobin <12 g/dL in men or postmenopausal women 6
• Assess iron stores (transferrin saturation >20%, ferritin >100 ng/mL) before considering erythropoiesis-stimulating agents 1, 6
• Screen for other causes of anemia including vitamin B12/folate deficiency, blood loss, and inflammation before attributing anemia solely to CKD 6

Nephrology Referral Indications

Refer to nephrology if any of the following are present: 4

• Persistent proteinuria >1 g/day (UACR ≥60 mg/mmol or protein-to-creatinine ratio ≥100 mg/mmol) 4
• Abrupt sustained eGFR decrease >20% after excluding reversible causes 4
• Blood pressure refractory to treatment with 4 or more antihypertensive agents 4
• eGFR <30 mL/min/1.73m² (progression to stage 3B or worse) 4
• Active urinary sediment (red/white blood cells, cellular casts) or rapidly increasing albuminuria suggesting alternative kidney disease 1

Monitoring Strategy

• Measure serum creatinine and calculate eGFR every 3 months to detect progression early 2
• Monitor electrolytes (particularly potassium) when using ACE inhibitors/ARBs 2
• Recheck UACR every 6-12 months to assess treatment response 1
• Adjust medication doses based on eGFR to prevent drug toxicity, as many medications require dose reduction in CKD 1, 7

Cardiovascular Risk Reduction

• Recognize that CKD stage 3 confers elevated cardiovascular risk independent of traditional risk factors 1, 4
• Address cardiovascular risk factors aggressively, including lipid management and smoking cessation 4
• Ensure adequate hydration before contrast imaging procedures, as dehydration combined with reduced kidney function increases contrast-induced nephropathy risk 2

Dietary Modifications

• Restrict sodium intake to <2.3 g/day to reduce volume retention and facilitate blood pressure control 8
• Limit protein intake to maximum 0.8 g/kg/day for stage 3 CKD to reduce metabolic burden on kidneys 8