What are the management recommendations for a patient with stage 4 Chronic Kidney Disease (CKD) and a Glomerular Filtration Rate (GFR) of 22?

Management of Stage 4 CKD (GFR 22)

Refer immediately to nephrology, as consultation at stage 4 CKD (eGFR <30 mL/min/1.73 m²) reduces costs, improves quality of care, delays dialysis, and allows timely preparation for renal replacement therapy. 1, 2

Immediate Nephrology Referral

• All patients with stage 4 CKD require immediate nephrology referral regardless of other factors 2
• Begin patient education about renal replacement therapy options (hemodialysis, peritoneal dialysis, transplantation) immediately upon reaching stage 4, as progression rates are unpredictable and preparation takes months 2
• Evaluate for preemptive kidney transplantation including living donor assessment 2
• For patients likely requiring hemodialysis, plan arteriovenous fistula creation in advance, as maturation may take weeks to months 2

Blood Pressure Management

Target and First-Line Therapy

• Target systolic blood pressure <120 mmHg when tolerated using standardized office measurement 2, 3
• Start ACE inhibitor or ARB as first-line therapy for blood pressure control and proteinuria reduction 2, 3
• Monitor serum creatinine and potassium within 2-4 weeks of initiating or increasing ACE inhibitor/ARB dose 2, 3
• Continue ACE inhibitor/ARB unless creatinine rises >30% within 4 weeks of starting therapy 2, 3
• Never combine ACE inhibitor with ARB due to increased risk of hyperkalemia and acute kidney injury 2, 3

Volume Management

• Use loop diuretics (not thiazides) for volume control in patients with fluid overload 2, 3
• Restrict dietary sodium to <2g per day to enhance blood pressure control 2, 3

Hyperkalemia Management

• Manage hyperkalemia with dietary potassium restriction and potassium binders rather than immediately discontinuing ACE inhibitor/ARB 2, 3

Diabetes Management (If Applicable)

SGLT2 Inhibitors

• Start SGLT2 inhibitor if patient has type 2 diabetes and eGFR ≥20 mL/min/1.73 m² 1, 2, 4
• Continue SGLT2 inhibitor even if eGFR falls below 20 mL/min/1.73 m² unless not tolerated or dialysis initiated 1, 2, 4
• For patients with eGFR 15-29 mL/min/1.73 m²: canagliflozin 100 mg daily may be continued if tolerated; dapagliflozin 10 mg daily may be continued if tolerated 1

Alternative Glucose-Lowering Agents

• Use glipizide as preferred sulfonylurea due to lack of active metabolites 2, 4
• DPP-4 inhibitors with dose adjustments: sitagliptin maximum 25 mg daily, saxagliptin maximum 2.5 mg daily, or linagliptin (no dose adjustment required) 1, 4
• Insulin requires careful dose adjustment due to reduced renal clearance 2, 4
• Reduce metformin dose or discontinue (contraindicated at eGFR <30 mL/min/1.73 m²) 1

Finerenone Consideration

• Consider finerenone (non-steroidal mineralocorticoid receptor antagonist) for patients with type 2 diabetes and elevated albuminuria, starting at 10 mg once daily with eGFR 25-60 mL/min/1.73 m² if potassium ≤4.8 mmol/L 1
• Monitor potassium closely as hyperkalemia occurs in approximately 10.8% of patients 1

Monitoring for Complications

Mineral and Bone Disorder

• Monitor serum calcium and phosphorus every 3-6 months 2
• Monitor PTH every 6-12 months 2
• Measure alkaline phosphatase annually or more frequently if PTH elevated 2
• Measure 25(OH)D levels and correct deficiency using general population treatment strategies 2

Anemia

• Perform complete blood count at least monthly after initial stabilization 2
• Assess and treat anemia by removing underlying causes before considering erythropoietin-stimulating agents 2
• If using epoetin alfa, initiate only when hemoglobin <10 g/dL at starting dose of 50-100 Units/kg three times weekly, targeting hemoglobin sufficient to reduce transfusion need (not exceeding 11 g/dL for dialysis patients or 10 g/dL for non-dialysis patients) 5

Metabolic and Electrolyte Monitoring

• Monitor regularly for hyperkalemia, metabolic acidosis, and electrolyte abnormalities 2
• Check serum creatinine, potassium, and blood pressure within 2-4 weeks of starting ACE inhibitor/ARB 2, 3

Cardiovascular Risk

• Monitor for cardiovascular disease as CKD patients have markedly elevated cardiovascular mortality 2, 6

Medication Adjustments and Avoidance

• Avoid nephrotoxic agents including NSAIDs, COX-2 inhibitors, and contrast media 2, 6
• Adjust dosing for renally cleared medications including many antibiotics and oral hypoglycemic agents 6
• Avoid allopurinol in patients receiving azathioprine 2

Indications for Urgent Intervention

• Refer urgently for uremic symptoms, BUN >100 mg/dL, or altered mental status 2, 3
• Consider dialysis initiation for refractory volume overload, severe hyperkalemia, uremic encephalopathy, pericarditis, or severe metabolic acidosis (pH <7.2) 2

Common Pitfalls to Avoid

• Do not delay nephrology referral waiting for further GFR decline—stage 4 CKD is the threshold for mandatory referral 1, 2
• Do not discontinue ACE inhibitor/ARB for mild creatinine increases (<30% rise) or mild hyperkalemia that can be managed with dietary restriction and binders 2, 3
• Do not use thiazide diuretics for volume management at this GFR level—loop diuretics are required 2, 3
• Do not target hemoglobin >11 g/dL with erythropoietin-stimulating agents, as this increases mortality and cardiovascular risk 5