GFR of 25 mL/min/1.73 m² Indicates CKD Stage 4
A GFR of 25 mL/min/1.73 m² corresponds to Stage 4 chronic kidney disease, defined as severely decreased kidney function with GFR between 15-29 mL/min/1.73 m² 1.
CKD Staging Framework
The chronic kidney disease classification system divides kidney function into five stages based on GFR 1, 2:
- Stage 1: GFR ≥90 mL/min/1.73 m² with evidence of kidney damage (proteinuria or other markers) 1
- Stage 2: GFR 60-89 mL/min/1.73 m² 1
- Stage 3: GFR 30-59 mL/min/1.73 m² (moderately decreased) 1
- Stage 4: GFR 15-29 mL/min/1.73 m² (severely decreased) 1
- Stage 5: GFR <15 mL/min/1.73 m² or requiring dialysis (kidney failure) 1
Clinical Implications of Stage 4 CKD
At this stage, patients face significantly elevated risks for both progression to kidney failure and cardiovascular mortality 2. The GFR of 25 mL/min/1.73 m² places the patient firmly in the severely decreased kidney function category, requiring intensive monitoring and management 1, 3.
Required Monitoring Schedule
- Laboratory evaluations including eGFR should be performed every 3-5 months at baseline 3
- More frequent monitoring (every 1-3 months) is necessary if there are medication changes affecting kidney function, signs of disease progression, or approaching Stage 5 3
Complications Screening
When eGFR falls below 60 mL/min/1.73 m², and particularly at Stage 4, screening for CKD complications becomes mandatory 1:
- Anemia: Check hemoglobin regularly, as anemia prevalence increases substantially at this stage 1, 3
- Metabolic bone disease: Monitor serum calcium, phosphate, PTH, and 25(OH)D levels 1, 3
- Electrolyte abnormalities: Assess for hyperkalemia and metabolic acidosis 3
- Vitamin D insufficiency: Common in patients with GFR 20-60 mL/min/1.73 m², with 47-76% having deficient levels 1
Nephrology Referral
Consultation with a nephrologist is strongly recommended when Stage 4 CKD develops, as this has been shown to reduce costs, improve quality of care, and delay dialysis 1. The threshold for referral should not be delayed, particularly given the proximity to Stage 5 and potential need for renal replacement therapy planning 1.
Important Clinical Pitfalls
- Do not confuse small creatinine elevations (up to 30%) with ACE inhibitors or ARBs as acute kidney injury—these are expected hemodynamic changes 3
- Avoid nephrotoxic medications and hold certain medications during acute illness to prevent further kidney injury 3
- Remember that eGFR trajectories vary: approximately 72% of Stage 4 patients show slow decline, 18% show fast decline, and 10% show initial stability followed by rapid decline 4
- GFR improvement is possible even at Stage 4 when therapeutic targets are optimized, though this occurs in only about 15% of patients 5
Additional Management Priorities
Beyond staging, patients at this level require 1, 3:
- Optimization of blood pressure control with ACE inhibitors or ARBs (if tolerated) 1
- Monitoring of albuminuria to assess disease progression 1, 3
- Assessment of cardiovascular risk factors, as CKD is considered a coronary heart disease risk equivalent 6
- Patient education about disease progression and potential need for renal replacement therapy 1