What is the management plan for a patient with impaired renal function (eGFR of 25) and elevated urine microalbumin (131)?

Management of CKD Stage G4 with Elevated Albuminuria

This patient requires immediate nephrology referral, initiation of ACE inhibitor or ARB therapy (if not already on it), SGLT2 inhibitor consideration if diabetic, strict blood pressure control to ≤130/80 mmHg, and dietary protein restriction to 0.8 g/kg/day. 1

Immediate Referral to Nephrology

Refer this patient to a nephrologist immediately given the eGFR of 25 mL/min/1.73 m² (Stage G4 CKD). 1 The 2024 ADA guidelines explicitly recommend nephrology referral when eGFR is <30 mL/min/1.73 m², as this patient is approaching Stage G5 (end-stage kidney disease) and requires specialized management planning including potential preparation for renal replacement therapy. 1

• Referral is also indicated due to the continuously elevated albuminuria (131 mg/g represents moderately increased albuminuria in the A2 category). 1
• The combination of severely reduced eGFR and elevated albuminuria places this patient at very high risk for both CKD progression and cardiovascular events. 1

Renin-Angiotensin System Blockade

Initiate or optimize ACE inhibitor or ARB therapy immediately as first-line treatment for albuminuria reduction and renoprotection. 1

• ACE inhibitors or ARBs are recommended for all patients with albuminuria ≥30 mg/g (this patient has 131 mg/g), even if blood pressure is not elevated. 1
• These agents reduce proteinuria and slow CKD progression through both hemodynamic and non-hemodynamic mechanisms. 2, 3
• Critical monitoring caveat: At eGFR 25, expect and accept modest increases in serum creatinine (up to 30%) after initiating therapy, as this reflects appropriate hemodynamic changes rather than true kidney injury. 4
• Monitor serum potassium closely (within 1-2 weeks of initiation) as hyperkalemia risk is elevated at this level of renal function. 1, 5
• Dose adjustment is required: For lisinopril and most ACE inhibitors, reduce the dose by 50% when creatinine clearance is ≤30 mL/min. 5

SGLT2 Inhibitor Therapy (If Diabetic)

If this patient has type 2 diabetes, add an SGLT2 inhibitor immediately as it provides both renoprotection and cardiovascular risk reduction. 1

• SGLT2 inhibitors are recommended for patients with eGFR ≥20 mL/min/1.73 m² and albuminuria ≥30 mg/g (this patient qualifies on both criteria). 1
• These agents reduce CKD progression and cardiovascular events independent of glucose-lowering effects. 1
• Continue SGLT2 inhibitor therapy even as eGFR declines, as long as it remains ≥20 mL/min/1.73 m². 1

Nonsteroidal Mineralocorticoid Receptor Antagonist

Consider adding a nonsteroidal MRA (such as finerenone) for additional cardiovascular and renal protection if the patient has diabetes. 1

• Nonsteroidal MRAs are recommended for patients with eGFR ≥25 mL/min/1.73 m² and albuminuria to reduce both cardiovascular events and CKD progression. 1
• This patient's eGFR of 25 is at the threshold, so careful monitoring is essential if initiated. 1
• Hyperkalemia monitoring is critical: Check potassium within 1 week of initiation and regularly thereafter. 1

Blood Pressure Management

Target blood pressure ≤130/80 mmHg given the presence of albuminuria ≥30 mg/g. 1

• Patients with CKD and albuminuria ≥30 mg/24 hours require more aggressive BP targets (≤130/80) compared to those without albuminuria (≤140/90). 1
• Use ACE inhibitor or ARB as the foundation of antihypertensive therapy. 1
• Add additional agents as needed to achieve target, with loop diuretics preferred over thiazides at this level of renal function. 4
• Avoid NSAIDs completely as they reduce renal blood flow, worsen kidney function, and can precipitate acute kidney injury. 6, 7

Dietary Protein Restriction

Restrict dietary protein intake to 0.8 g/kg body weight per day. 1

• This level of protein restriction slows CKD progression in non-dialysis-dependent Stage G3 or higher CKD. 1
• Also restrict dietary sodium to <2 g/day (<90 mmol/day) to maximize effectiveness of antihypertensive and diuretic therapy. 4
• Do not restrict protein below 0.8 g/kg/day as this may lead to protein-energy wasting. 1

Albuminuria Reduction Target

Aim for at least a 30% reduction in albuminuria from the baseline of 131 mg/g to slow CKD progression. 1

• A 30% or greater reduction in urinary albumin is recommended to slow CKD progression in patients with ≥300 mg/g albuminuria, but this principle applies to all levels of elevated albuminuria. 1
• Monitor albuminuria every 3-6 months to assess treatment response and adjust therapy accordingly. 1
• Increasing albuminuria despite treatment suggests progression and warrants treatment intensification. 1

Monitoring Frequency

Monitor eGFR and albuminuria every 3 months given the Stage G4 CKD with elevated albuminuria. 1

• The KDIGO guidelines recommend monitoring 3-4 times per year for patients with eGFR 15-29 and albuminuria in the A2 category (30-300 mg/g). 1
• Also monitor serum potassium, bicarbonate, calcium, phosphate, parathyroid hormone, and hemoglobin regularly for CKD complications. 7
• Define progression as both a change in eGFR category AND ≥25% decline in eGFR to avoid misinterpreting normal fluctuations. 1

Cardiovascular Risk Reduction

Initiate statin therapy for cardiovascular risk reduction, as CKD with albuminuria markedly increases cardiovascular risk. 7, 8

• Microalbuminuria is a marker of endothelial dysfunction and generalized vascular damage, not just kidney disease. 2, 8, 9
• The presence of both reduced eGFR and elevated albuminuria independently increases risk of cardiovascular mortality. 7, 8
• Target LDL cholesterol <100 mg/dL (or <120 mg/dL if non-diabetic). 2

Medication Adjustments and Avoidance

Review all medications for appropriate dosing and nephrotoxicity at this level of renal function. 7

• Many antibiotics, oral hypoglycemic agents, and other drugs require dose adjustment when eGFR <30 mL/min. 7
• Absolutely avoid NSAIDs, including over-the-counter ibuprofen and naproxen, as they can precipitate acute kidney injury. 4, 6, 7
• Temporarily hold ACE inhibitors, ARBs, and diuretics during episodes of volume depletion (vomiting, diarrhea, excessive sweating). 6

Additional Considerations

• Smoking cessation is essential if the patient smokes, as smoking accelerates CKD progression. 1, 3
• Glycemic control with HbA1c target <7% if diabetic to prevent further kidney damage. 1, 2
• Weight management with BMI target <30 kg/m² if obese. 2
• Screen for and manage CKD complications including anemia, metabolic acidosis, hyperphosphatemia, and secondary hyperparathyroidism. 7