CKD Staging for a Patient with GFR of 25
A patient with a GFR of 25 mL/min/1.73 m² is classified as having Stage 4 Chronic Kidney Disease (CKD). 1
CKD Staging System
The Kidney Disease: Improving Global Outcomes (KDIGO) classification system categorizes CKD into five stages based on glomerular filtration rate (GFR):
| Stage | GFR (mL/min/1.73 m²) | Description |
|---|---|---|
| G1 | ≥90 | Normal or elevated GFR with evidence of kidney damage |
| G2 | 60-89 | Mildly decreased GFR |
| G3a | 45-59 | Mildly to moderately decreased GFR |
| G3b | 30-44 | Moderately to severely decreased GFR |
| G4 | 15-29 | Severely decreased GFR |
| G5 | <15 | Kidney failure |
With a GFR of 25 mL/min/1.73 m², this patient falls within the Stage 4 (G4) category, which represents severely decreased kidney function 1.
Clinical Implications of Stage 4 CKD
Stage 4 CKD represents advanced kidney disease with significant clinical implications:
Mortality and Morbidity Risk: Patients with Stage 4 CKD have significantly increased risks of cardiovascular events, progression to kidney failure, and death 2.
Complications: At this stage, patients commonly develop complications that require monitoring and management 3:
- Anemia
- Metabolic bone disease
- Electrolyte abnormalities
- Metabolic acidosis
- Volume overload
- Hypertension
Medication Management: Many medications require dose adjustments or may be contraindicated at this level of kidney function 1:
- Metformin is contraindicated when eGFR <30 mL/min/1.73 m²
- Many antibiotics and other drugs require dose adjustment
Monitoring and Management Recommendations
For a patient with Stage 4 CKD (GFR 25 mL/min/1.73 m²), the following monitoring schedule is recommended:
- Laboratory evaluations every 3-5 months 3
- Blood pressure monitoring at every clinical contact
- Regular assessment for complications of CKD
Referral to Nephrology
A patient with Stage 4 CKD (GFR <30 mL/min/1.73 m²) should be promptly referred to a nephrologist 1, 4. This is critical for:
- Preparation for potential kidney replacement therapy
- Management of CKD complications
- Slowing disease progression
- Reducing cardiovascular risk
Prognosis
Patients with Stage 4 CKD have variable trajectories of kidney function decline 5:
- Some may experience slow, consistent decline (approximately -2.45 mL/min/1.73 m² per year)
- Others may have faster decline (approximately -8.60 mL/min/1.73 m² per year)
- A third pattern shows variable decline rates over time
The 1-year risk for progression to kidney failure or death is significantly higher in Stage 4 CKD compared to earlier stages 5.
Common Pitfalls to Avoid
Relying on a single GFR measurement: CKD diagnosis requires persistent abnormalities for >3 months 6.
Overlooking albuminuria: The complete CKD classification includes both GFR and albuminuria categories 1.
Delaying nephrology referral: Early specialist involvement improves outcomes for patients with advanced CKD 1, 4.
Continuing nephrotoxic medications: NSAIDs and other nephrotoxins should be avoided in Stage 4 CKD 2, 4.
Missing complications: Regular screening for anemia, metabolic bone disease, and other complications is essential at this stage 3.