eGFR 15 to 29 mL/min/1.73m²

KDIGO labels 15 to 29 "Severely decreased," and this is the band where its referral figure names the number outright: "eGFR <30 ml/min per 1.73 m2," with the stated goal "Planning and preparation for kidney replacement therapy." The guideline's transition figure puts it the same way, "eGFR <30 Transition from nephrology care to interprofessional care" and "eGFR <20 Access and transplant planning." Monitoring is three times a year at A1 and A2 and four or more times a year at A3.

What planning means here, and what it does not. KDIGO is careful about timing. Practice Point 5.4.3: "Consider planning for preemptive kidney transplantation and/or dialysis access in adults when the GFR is <15–20 ml/min per 1.73 m2 or risk of KRT is >40% over 2 years." A 2-year kidney failure risk over 10 percent is its trigger for multidisciplinary care, and over 40 percent for modality education and access planning; it warns that "Vascular access planning in all adults with CKD G4 would lead to the unnecessary placement of fistulae." The guideline says the point at which it advises beginning to plan "is intentionally advised at a conservative time point," and it asks that people be told about every option, including comprehensive conservative care without dialysis. The team it describes covers dietary counseling, medication management, education about modalities and transplant, access surgery, and psychological and social care.

Why complications get screened now. KDIGO: "People with CKD G4–G5 are more likely to develop concurrent complications of CKD including anemia, hyperkalemia, bone mineral disorders, and/or metabolic acidosis and protein-energy wasting," and they "remain at high risk for adverse events including AKI, emergency department visits, and hospitalizations." Its practice points at G4 to G5 include screening for malnutrition twice a year, asking about uremic symptoms (reduced appetite, nausea, fatigue) at each consultation, treating acidosis when bicarbonate falls under 18 mmol/l, and caution with non-vitamin K anticoagulants, which need dose adjustment for GFR. For MRI contrast at GFR under 30, KDIGO prefers the American College of Radiology's group II and III gadolinium agents.

Medicines KDIGO keeps going. "Continue ACEi or ARB in people with CKD even when the eGFR falls below 30"; the STOP-ACEi trial, in which participants had a mean eGFR of 13, found that stopping brought no kidney or cardiovascular benefit. SGLT2 inhibitor recommendations extend down to an eGFR of 20, and once started it is reasonable to continue below 20 unless not tolerated or dialysis begins. A statin or statin plus ezetimibe stays recommended for adults 50 and older, though KDIGO notes the relative risk reductions "become progressively smaller as eGFR declines." A nonsteroidal mineralocorticoid receptor antagonist is suggested only for type 2 diabetes with an eGFR over 25, normal potassium and albuminuria despite a maximally tolerated ACE inhibitor or ARB. Drug dosing by GFR, and avoiding NSAIDs, apply with more force at every step down.