How to manage a patient with impaired renal function, stage 4 Chronic Kidney Disease (CKD), and an eGFR of 29?

Management of Stage 4 CKD (eGFR 29 mL/min/1.73 m²)

Refer this patient to nephrology immediately, as all patients with eGFR <30 mL/min/1.73 m² require specialist kidney care to prevent complications, prepare for renal replacement therapy, and optimize outcomes. 1, 2

Immediate Nephrology Referral

• All CKD stage 4 patients (eGFR 15-29 mL/min/1.73 m²) require formal nephrology referral to reduce late referral complications, improve survival, and allow adequate time for dialysis preparation or transplant evaluation 1, 2
• Begin structured education about renal replacement options (hemodialysis, peritoneal dialysis, kidney transplantation, or conservative management) now, as progression timing is unpredictable and preparation requires months 1, 2
• Evaluate for preemptive kidney transplantation including living donor assessment 2

Blood Pressure Management

Target systolic blood pressure <120 mmHg using standardized office measurement when tolerated. 2, 3

• Start ACE inhibitor (e.g., lisinopril) or ARB as first-line therapy for blood pressure control and proteinuria reduction 1, 2, 3
• Monitor serum creatinine and potassium within 2-4 weeks of starting or increasing ACE inhibitor/ARB dose 2, 3
• Continue ACE inhibitor/ARB unless creatinine rises >30% within 4 weeks of initiation 3
• Never combine ACE inhibitor with ARB due to increased hyperkalemia and acute kidney injury risk 3
• Manage hyperkalemia with dietary potassium restriction (<2g/day) and potassium binders rather than immediately discontinuing ACE inhibitor/ARB 3

Volume Management

• Use loop diuretics (not thiazides) for volume control if signs of fluid overload present (peripheral edema, pulmonary crackles, jugular venous distension) 2, 3
• Restrict dietary sodium to <2g per day to enhance blood pressure control 2, 3

Diabetes Management (If Applicable)

Start SGLT2 inhibitor (canagliflozin 100 mg daily, or dapagliflozin 10 mg daily) if patient has type 2 diabetes, as kidney and cardiovascular benefits persist at this eGFR level. 1, 2, 3

• Continue SGLT2 inhibitor even if eGFR falls below 20 mL/min/1.73 m² unless not tolerated or dialysis initiated 1, 2, 3
• Adjust other diabetes medications per Table 4: 1
  • Metformin: contraindicated at eGFR <30 mL/min/1.73 m²
  • Insulin: reduce dose due to decreased renal clearance and hypoglycemia risk
  • Sitagliptin: maximum 25 mg daily; saxagliptin: maximum 2.5 mg daily; linagliptin: no adjustment 1
  • Glipizide: initiate conservatively at 2.5 mg daily; avoid glyburide (contraindicated) 1
  • GLP-1 agonists (dulaglutide, liraglutide, semaglutide): no dose adjustment required 1

Monitoring CKD Complications

Mineral and Bone Disorder

• Monitor serum calcium and phosphorus every 3-6 months 2
• Monitor PTH every 6-12 months 2
• Measure 25(OH)D levels and correct deficiency using standard treatment 2

Anemia

• Perform complete blood count at least monthly after initial stabilization 2
• Assess and treat underlying causes before initiating erythropoiesis-stimulating agents 2

Metabolic Monitoring

• Monitor for hyperkalemia, metabolic acidosis (serum bicarbonate), and electrolyte abnormalities regularly 2, 4
• Correct metabolic acidosis to slow CKD progression 5

Cardiovascular Risk

• Initiate statin therapy for cardiovascular risk reduction 4, 5
• Monitor for cardiovascular disease as CKD patients have markedly elevated cardiovascular mortality 2

Medication Safety

Avoid nephrotoxic agents: 2, 4, 5

• NSAIDs and COX-2 inhibitors (contraindicated)
• Contrast media (use only when essential with appropriate hydration protocols)
• Aminoglycoside antibiotics when alternatives exist

Adjust medication doses based on eGFR for renally cleared drugs (many antibiotics, oral hypoglycemics, anticoagulants) 4, 5

Preparation for Renal Replacement Therapy

• Begin vascular access planning if hemodialysis likely: create arteriovenous fistula in advance as maturation requires weeks to months 2
• For peritoneal dialysis candidates, delay AVF creation and focus on PD catheter planning 2
• Educate patient and family about all modalities including conservative kidney management for those unlikely to benefit from dialysis 6

Urgent Indications for Dialysis Consideration

Refer urgently if any of the following develop: 2, 3

• Uremic symptoms (encephalopathy, pericarditis, bleeding)
• BUN >100 mg/dL with altered mental status
• Refractory volume overload despite diuretics
• Severe hyperkalemia unresponsive to medical management
• Severe metabolic acidosis (pH <7.2)

Follow-Up Schedule

• Recheck serum creatinine, potassium, and blood pressure within 2-4 weeks of starting ACE inhibitor/ARB 2, 3
• Nephrology follow-up frequency determined by specialist, typically every 1-3 months for stage 4 CKD 7
• Monitor eGFR trajectory: 38% of stage 4 patients show linear decline, but 35% remain stable and 10% improve with optimal management 7, 8

Common Pitfalls to Avoid

• Late nephrology referral (defined as <1 year before dialysis initiation) worsens outcomes and increases mortality 1, 2
• Continuing metformin at eGFR <30 mL/min/1.73 m² increases lactic acidosis risk 1
• Discontinuing ACE inhibitor/ARB prematurely for mild creatinine elevation (<30% increase) or hyperkalemia before attempting medical management 3, 8
• Failing to educate about renal replacement options early, leading to inadequate preparation time 1, 2