Staging of Chronic Kidney Disease to Guide Treatment
CKD staging directly guides treatment strategies, with interventions becoming more intensive and specialized as kidney function declines through stages 1-5, focusing on slowing progression in early stages and preparing for renal replacement therapy in advanced stages.
CKD Classification and Staging
CKD is classified into 5 stages based primarily on estimated glomerular filtration rate (eGFR):
| Stage | GFR (mL/min/1.73 m²) | Description | Key Focus |
|---|---|---|---|
| 1 | >90 with kidney damage | Normal kidney function with evidence of damage | Diagnosis and risk factor management |
| 2 | 60-89 with kidney damage | Mild decrease in kidney function | Risk factor management |
| 3 | 30-59 | Moderate decrease in kidney function | Treating complications |
| 4 | 15-29 | Severe decrease in kidney function | Preparation for renal replacement therapy |
| 5 | <15 or dialysis | Kidney failure | Renal replacement therapy |
Stage-Specific Treatment Approach
Stages 1-2 (eGFR ≥60 mL/min/1.73 m² with evidence of kidney damage)
- Primary focus: Diagnosis of underlying cause and slowing progression 1
- Key interventions:
- Blood pressure control (target <140/90 mmHg)
- ACE inhibitors or ARBs for those with albuminuria
- Glycemic control for diabetic patients
- Lifestyle modifications (smoking cessation, weight management)
- Cardiovascular risk reduction (statins)
Stage 3 (eGFR 30-59 mL/min/1.73 m²)
- Primary focus: Managing complications and slowing progression 1
- Key interventions:
- Continue all Stage 1-2 interventions
- Monitor and treat emerging complications:
- Avoid nephrotoxins (NSAIDs, certain antibiotics)
- Medication dose adjustments
Stage 4 (eGFR 15-29 mL/min/1.73 m²)
- Primary focus: Preparation for renal replacement therapy (RRT) and intensive complication management 1
- Key interventions:
- Continue all previous interventions
- More frequent monitoring of complications:
- Patient education about RRT options (transplantation, peritoneal dialysis, hemodialysis) 1
- Vascular access planning if hemodialysis anticipated
- Transplant evaluation if appropriate
Stage 5 (eGFR <15 mL/min/1.73 m²)
- Primary focus: Renal replacement therapy or conservative management 1
- Key interventions:
- Initiation of dialysis or transplantation
- For conservative management: symptom control, fluid management, dietary restrictions
- Continued management of complications
- Palliative care discussions when appropriate
Monitoring Frequency Based on CKD Stage
The frequency of monitoring increases with advancing CKD stage:
- Stage 1-2: Annual monitoring of eGFR, albuminuria, and cardiovascular risk factors
- Stage 3: Monitor eGFR, electrolytes every 3-6 months; complications as noted above
- Stage 4: Monitor eGFR, electrolytes every 1-3 months; complications as noted above
- Stage 5: Monthly monitoring of all parameters if not on dialysis
Special Considerations
Referral to Nephrology
Referral to nephrology should be considered for:
- Rapid decline in eGFR (>5 mL/min/1.73 m² per year)
- All patients with Stage 4-5 CKD 1
- Heavy proteinuria (>1g/day)
- Difficult-to-control hypertension
- Recurrent or extensive nephrolithiasis
Common Pitfalls to Avoid
- Overdiagnosis in elderly: Many elderly patients have reduced eGFR but stable function. Age should be considered when interpreting eGFR values 2.
- Nephrotoxic medications: Avoid NSAIDs, adjust medication doses appropriately.
- Contrast-induced nephropathy: Use caution with contrast studies in advanced CKD.
- Late referral: Patients should be referred to nephrology well before reaching Stage 5 to allow adequate preparation for RRT.
- Overlooking cardiovascular risk: CKD patients have significantly elevated cardiovascular risk requiring aggressive management.
By following this stage-based approach to CKD management, clinicians can systematically address the evolving needs of patients as their kidney function declines, potentially slowing disease progression and improving outcomes.