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

Disease Classification & Prognosis

Stage G4 CKD is defined by an estimated glomerular filtration rate of 15–29 mL/min/1.73 m², representing roughly 15 % of normal kidney function【1】.
Patients with Stage G4 CKD have markedly increased risks of cardiovascular disease, progression to end‑stage kidney disease, and mortality【1】.

An urgent referral to a nephrology specialist is required for any adult with eGFR < 30 mL/min/1.73 m²【1】.
Referral is indicated even in the absence of symptoms, because preparation for renal replacement therapy (RRT) often requires several months【3】.

Electrolyte panel (serum potassium, sodium, bicarbonate, calcium, phosphorus) should be obtained at the time of referral【2】.
Metabolic acidosis assessment via serum bicarbonate is recommended, as acidosis is common at this stage【2】.
Anemia evaluation (hemoglobin and iron studies) is essential because reduced erythropoietin production is nearly universal【2】.
Mineral‑bone disorder work‑up (calcium, phosphorus, parathyroid hormone) should be performed promptly【3】.
Volume status and blood pressure should be assessed, targeting a BP < 130/80 mmHg【3】.

All chronic medications must be reviewed for dose reduction or discontinuation when eGFR < 30 mL/min/1.73 m²; many agents require substantial dose adjustments【4】.
NSAIDs should be strictly avoided because they can precipitate acute kidney injury【3】.
Metformin must be stopped at eGFR < 30 mL/min/1.73 m² due to the risk of lactic acidosis【4】.

SGLT2 inhibitors may be continued if already prescribed and the patient’s eGFR is ≥ 20 mL/min/1.73 m², given their cardiovascular and renal benefits【4】.
New SGLT2 inhibitors should not be initiated when eGFR < 20 mL/min/1.73 m²【4】.
GLP‑1 receptor agonists (e.g., dulaglutide, semaglutide, liraglutide) are preferred glucose‑lowering agents at this level of kidney function【4】.
Target glycated hemoglobin ≈ 7 % to help slow CKD progression【5】.
Measure urine albumin‑to‑creatinine ratio (UACR) at least annually; if UACR ≥ 300 mg/g, consider a non‑steroidal mineralocorticoid receptor antagonist (provided eGFR ≥ 25 mL/min/1.73 m²) to reduce cardiovascular events and CKD progression【1】.

Protein intake should be limited to ~0.8 g/kg body weight per day to lessen uremic toxin generation【5】.
Sodium restriction to < 2 g/day helps control blood pressure and fluid retention【3】.
Potassium restriction is generally required to avoid life‑threatening hyperkalaemia【2】.
Phosphorus restriction is advised to slow progression of mineral‑bone disease【2】.

Initiate dialysis planning when eGFR approaches 15 mL/min/1.73 m² or when uremic symptoms develop【2】.
Discuss modality options (hemodialysis vs. peritoneal dialysis) with the nephrology team【6】.
If hemodialysis is chosen, arrange creation of an arteriovenous fistula, which requires 3–6 months to mature【6】.
Evaluate eligibility for kidney transplantation where appropriate【2】.
Administer hepatitis B vaccination early, as many patients will progress to end‑stage kidney disease【3】.

Creatinine‑based eGFR may be inaccurate in patients with extreme muscle mass, malnutrition, or non‑steady‑state conditions; consider cystatin C‑based eGFR when estimates appear discordant (creatinine eGFR is inaccurate in ~16‑20 % of individuals with eGFR < 60 mL/min/1.73 m²)【7】.
Repeat eGFR measurement within 3 months to confirm chronicity, as CKD requires persistent abnormalities for ≥ 3 months【3】.
Rapid eGFR decline (> 5 mL/min/1.73 m² per year) is associated with worse outcomes compared with stable severe CKD【2】.
Failure to adjust medication doses at eGFR < 30 mL/min/1.73 m² is a common and dangerous error【3】.
Continuing metformin below the eGFR threshold markedly increases the risk of fatal lactic acidosis【4】.
NSAID use can trigger acute‑on‑chronic kidney injury, potentially necessitating emergency dialysis【3】.