Stages of Chronic Kidney Disease and Their Management
Chronic kidney disease (CKD) is classified into five stages based on glomerular filtration rate (GFR), with specific management strategies required at each stage to reduce morbidity and mortality.
CKD Definition and Classification
CKD is defined as kidney damage or GFR <60 mL/min/1.73 m² persisting for at least 3 months 1. Kidney damage can be identified through markers including proteinuria, abnormalities in urine sediment, blood and urine chemistry measurements, or abnormal findings on imaging studies 2.
The five stages of CKD according to the Kidney Disease Outcomes Quality Initiative (KDOQI) classification are:
| Stage | Description | GFR (mL/min/1.73 m²) |
|---|---|---|
| 1 | Kidney damage with normal or increased GFR | ≥90 |
| 2 | Kidney damage with mild decrease in GFR | 60-89 |
| 3 | Moderate decrease in GFR | 30-59 |
| 4 | Severe decrease in GFR | 15-29 |
| 5 | Kidney failure | <15 or dialysis |
Stage-Specific Management Approaches
Stage 1-2 (GFR ≥60 mL/min/1.73 m²)
- Focus: Screening, diagnosis, and CKD risk reduction 1
- Key interventions:
- Identify and treat underlying causes (diabetes, hypertension)
- Blood pressure control (target <130/80 mmHg)
- Glycemic control in diabetics (HbA1c target individualized based on comorbidities)
- Cardiovascular disease risk reduction
- Monitor GFR and albuminuria every 12 months 1
- ACE inhibitors or ARBs for patients with albuminuria 1
Stage 3 (GFR 30-59 mL/min/1.73 m²)
- Focus: Slowing progression and managing complications 1
- Key interventions:
- Continue all Stage 1-2 interventions
- Monitor GFR and albuminuria every 6 months
- Evaluate for anemia (hemoglobin monitoring)
- Monitor serum bicarbonate every 3 months
- Correct metabolic acidosis to serum bicarbonate ≥22 mmol/L 1
- Evaluate and control dyslipidemia with statins 1
- Dietary protein restriction (0.8 g/kg/day)
- Medication dose adjustments as needed
Stage 4 (GFR 15-29 mL/min/1.73 m²)
- Focus: Evaluating and treating complications, preparing for kidney replacement therapy 1
- Key interventions:
- Continue all previous stage interventions
- Monitor GFR and albuminuria every 3 months
- Manage mineral bone disorders (calcium, phosphorus, PTH)
- Manage anemia with erythropoiesis-stimulating agents as needed
- Monitor BP with each erythropoietin dose 1
- Begin education about kidney replacement therapy options
- Vascular access planning if hemodialysis anticipated
- Consider nephrology referral if not already done
Stage 5 (GFR <15 mL/min/1.73 m² or dialysis)
- Focus: Kidney replacement therapy or conservative management 1
- Key interventions:
- Initiate dialysis when clinically indicated
- Manage dialysis adequacy
- Continue management of all complications
- Kidney transplant evaluation and listing if appropriate 1
- Palliative care considerations for those choosing conservative management
Important Considerations and Pitfalls
Medication management: Many medications require dose adjustments or are contraindicated in advanced CKD:
Cardiovascular risk: CKD patients have significantly increased cardiovascular risk, with most patients dying from cardiovascular disease before reaching kidney failure 3
GFR estimation pitfalls: Relying solely on serum creatinine can lead to overestimation of kidney function, especially in elderly or malnourished patients 1, 4
Monitoring complications: Regular monitoring for anemia, metabolic acidosis, and mineral bone disorders becomes increasingly important as CKD progresses 1
Residual function: Preservation of residual kidney function, even at very low levels, remains important in both dialysis and non-dialysis stage 5 CKD patients 5
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 reducing complications.