Management of Stage G4 Chronic Kidney Disease (eGFR 15‑29 mL/min/1.73 m²)

Referral Recommendations

• Urgent nephrology referral is mandated when eGFR falls below 30 mL/min/1.73 m² to allow pre‑dialysis education, access planning, and evaluation of kidney‑replacement therapy options. (American Diabetes Association guidelines) 1

Monitoring Frequency and Laboratory Assessment

• eGFR and urinary albumin‑to‑creatinine ratio should be measured at least twice yearly in stable patients; more frequent testing is required if values are rapidly declining or the patient is clinically unstable. (American Diabetes Association guidelines) 1
• Immediate laboratory panel for CKD complications (serum potassium, calcium & phosphorus, parathyroid hormone, hemoglobin, bicarbonate, and urinary albumin‑to‑creatinine ratio) is recommended once eGFR is <60 mL/min/1.73 m². (Practice guideline) 2

Pharmacologic Therapy – Patients with Diabetes

• SGLT2 inhibitors may be continued if already established but should not be newly initiated when eGFR < 20 mL/min/1.73 m² (some agents allow use down to 20 mL/min/1.73 m²). (American Diabetes Association guidelines) 1
• Finerenone is recommended only when eGFR ≥ 25 mL/min/1.73 m² for cardiovascular and CKD‑progression risk reduction; patients with eGFR 18 mL/min/1.73 m² do not meet the threshold. (American Diabetes Association guidelines) 1
• GLP‑1 receptor agonists can be used for cardiovascular risk reduction without a specific eGFR cutoff; they are appropriate in Stage G4 CKD. (American Diabetes Association guidelines) 1
• ACE inhibitors or ARBs should be continued at maximally tolerated doses in patients with albuminuria ≥ 300 mg/g, and should not be stopped for creatinine rises ≤30 % unless volume depletion is evident. (American Diabetes Association guidelines) 3

Pharmacologic Therapy – Patients without Diabetes

• ACE inhibitor or ARB therapy is advised when albuminuria is present to slow progression and reduce cardiovascular risk. (Practice guideline) 2
• Statin therapy is recommended for cardiovascular risk reduction in all Stage G4 CKD patients regardless of diabetes status. (Practice guideline) 2

Blood Pressure Management

• Target systolic blood pressure < 120 mm Hg to attenuate CKD progression. (Practice guideline) 2
• Intensive BP lowering is considered safe even if serum creatinine rises up to 30 %, provided volume status is adequate. (Practice guideline) 2

Dietary and Lifestyle Interventions

• Limit dietary protein to ≤ 0.8 g/kg/day for non‑dialysis CKD stage G3 or higher to slow progression. (American Diabetes Association guidelines) 1
• Smoking cessation, ≥150 min/week of moderate‑intensity physical activity, and sodium restriction to < 2 g/day are recommended to improve cardiovascular and renal outcomes. (American College of Physicians recommendations) 4

Medication Safety

• All medications should be reviewed for dose adjustment at eGFR < 30 mL/min/1.73 m², with avoidance of nephrotoxins such as NSAIDs and iodinated contrast unless absolutely necessary. (Practice guideline) 2
• Metformin should be discontinued when eGFR falls below 30 mL/min/1.73 m² to prevent accumulation and lactic acidosis. (American College of Physicians recommendations) 4

Albuminuria Management

• If urinary albumin ≥ 300 mg/g, aim for ≥ 30 % reduction from baseline using ACE/ARB, SGLT2 inhibitor (if appropriate), and other renoprotective agents, as this correlates with better renal and cardiovascular outcomes. (American Diabetes Association guidelines) 1

Blood Pressure Management in Advanced CKD (Stage G4)

Blood Pressure Targets

• The Canadian Society of Nephrology recommends a target blood pressure of 140/90 mm Hg for patients with advanced chronic kidney disease, irrespective of diabetes or proteinuria status (older 2015 guidance). 5
• In the SPRINT CKD subgroup (eGFR 20–60 mL/min/1.73 m²), intensive control to systolic BP < 120 mm Hg reduced cardiovascular events (hazard ratio 0.81, 95 % CI 0.63–1.05) and all‑cause mortality (hazard ratio 0.72, 95 % CI 0.53–0.99) compared with a conventional target < 140 mm Hg. (Randomized trial evidence) 6

First‑Line Antihypertensive Selection

• ACE inhibitors or ARBs at maximally tolerated doses should be the foundational therapy when albuminuria is ≥300 mg/g, providing both blood‑pressure control and renoprotection. (Guideline recommendation) 7
• Dual blockade (ACE inhibitor + ARB) should be avoided because it increases adverse events without adding clinical benefit. (Guideline recommendation) 5

Continuation and Monitoring of RAS Blockade

• Continue ACE inhibitor or ARB therapy even if serum creatinine rises ≤30 % after initiation, unless there is clear evidence of volume depletion or an alternative acute kidney injury. (Guideline recommendation) 7
• Do not discontinue ACE inhibitor/ARB prematurely for modest creatinine increases (<30 %); stopping removes important renoprotective and cardiovascular benefits. (Guideline recommendation) 7

Additional Antihypertensive Agents

• Dihydropyridine calcium‑channel blockers or diuretics may be added as second‑line agents when ACE inhibitor/ARB monotherapy does not achieve the blood‑pressure target. (Guideline recommendation) 7
• In many patients with advanced CKD, combination therapy using an ACE inhibitor/ARB, a calcium‑channel blocker, and a diuretic is often required to reach the intensive systolic BP goal. (Guideline recommendation) 7

Pitfalls Specific to Advanced CKD

• Potassium‑sparing diuretics (e.g., spironolactone, amiloride) and non‑steroidal mineralocorticoid receptor antagonists (e.g., finerenone) should not be used at eGFR ≈ 17 mL/min/1.73 m²; finerenone is only recommended when eGFR ≥ 25 mL/min/1.73 m² because of heightened hyperkalemia risk. (Guideline recommendation) 7