What are the management options for a patient with mildly decreased kidney function?

Management of Mildly Decreased Kidney Function (eGFR 76 mL/min/1.73m²)

Your patient with a creatinine of 1.33 and eGFR of 76 mL/min/1.73m² has Stage 2 CKD (mild kidney function impairment), and management should focus on risk factor modification, annual monitoring, and prevention of progression rather than intensive intervention. 1

Classification and Prognosis

• This eGFR of 76 mL/min/1.73m² falls within Stage 2 CKD (GFR 60-89 mL/min/1.73m²), defined as mild renal insufficiency 2
• Small GFR variations of ±5-10% are common and can be affected by hydration status, diet, medication changes, and normal biological variability 1
• Stage 2 CKD requires the presence of kidney damage (albuminuria, structural abnormalities) in addition to the GFR range for formal diagnosis 3

Essential Initial Assessment

Measure urine albumin-to-creatinine ratio (UACR) immediately - this is the single most important test to determine disease severity and guide treatment intensity 1, 3:

• UACR <30 mg/g: Low risk, annual monitoring sufficient
• UACR 30-299 mg/g: Moderate risk, requires RAAS blockade
• UACR ≥300 mg/g: High risk, requires aggressive treatment and nephrology referral 3, 4

Identify the underlying cause 5, 3:

• Check HbA1c for diabetes (most common cause)
• Assess blood pressure control for hypertension (second most common)
• Review medication list for nephrotoxins (NSAIDs, proton-pump inhibitors) 5
• Consider alternative causes if diabetes/hypertension absent (autoimmune, genetic, obstructive)

Blood Pressure Management

Target blood pressure <140/90 mmHg 1:

• Monitor at each visit 1
• If UACR ≥30 mg/g, initiate ACE inhibitor or ARB regardless of blood pressure 1, 5
• ACE inhibitors/ARBs are first-line for kidney protection when albuminuria is present 5, 3

A common pitfall: A mild increase in creatinine (up to 30%) after starting ACE inhibitors/ARBs is expected and acceptable - do not discontinue unless creatinine rises >30% or potassium becomes dangerously elevated 2

Medication Management

Safe medications at this GFR level 6:

• Metformin is SAFE and does not require dose adjustment - it is only contraindicated when eGFR <30 mL/min/1.73m² 6
• Most medications do not require dose adjustment until eGFR <60 mL/min/1.73m² 2

Medications to avoid or use cautiously 5, 3:

• NSAIDs should be avoided entirely (accelerate CKD progression)
• Minimize proton-pump inhibitor use
• Avoid nephrotoxic antibiotics when alternatives exist
• For contrast procedures: ensure adequate hydration before and after 2

Monitoring Schedule

Annual monitoring is sufficient at this stage 1, 3:

• Check serum creatinine and eGFR annually 1
• Measure UACR at least once yearly 1
• Monitor blood pressure at each visit 1
• Check electrolytes (potassium) annually, more frequently if on RAAS inhibitors 3

More frequent monitoring (every 3-6 months) is needed if 3, 4:

• Rapid GFR decline >5 mL/min/1.73m²/year 1
• UACR ≥300 mg/g 1
• Starting or adjusting RAAS inhibitors 2

Cardiovascular Risk Reduction

Statin therapy should be initiated 3, 7:

• CKD is a cardiovascular disease risk equivalent
• All patients with CKD benefit from statin therapy regardless of baseline cholesterol 3

Consider SGLT2 inhibitors if diabetes or albuminuria present 5, 7:

• Recent evidence shows SGLT2 inhibitors are highly effective in slowing CKD progression in patients with diabetes and/or albuminuria 5
• This represents a major advance in CKD management 7

Lifestyle Modifications

Dietary recommendations 5:

• Sodium restriction to <2 grams/day
• Reduce animal protein intake (does not mean protein restriction at this stage)
• Maintain ideal body weight 5

Avoid nephrotoxins 5:

• No NSAIDs (including over-the-counter ibuprofen, naproxen)
• Minimize proton-pump inhibitors
• Ensure adequate hydration before iodinated contrast procedures 2

When to Refer to Nephrology

Nephrology referral is NOT needed at this stage 1, 3, but refer in the future if:

• eGFR declines to <30 mL/min/1.73m² 1, 4
• Rapid GFR decline >5 mL/min/1.73m²/year 1
• UACR ≥300 mg/g develops 1, 3
• Uncertainty about the etiology of kidney disease 1, 4
• Difficult-to-control hypertension despite multiple agents 3

Complications to Monitor (Not Yet Applicable)

At eGFR 76, complications of CKD are unlikely, but become relevant when eGFR <45 3:

• Anemia screening starts when eGFR <45
• Bone mineral disease monitoring starts when eGFR <45
• Metabolic acidosis screening when eGFR <30
• Hyperkalemia risk increases with RAAS inhibitors at any stage 2