Chronic Kidney Disease (CKD) Staging and Management Guidelines
CKD is defined as kidney damage or glomerular filtration rate (GFR) <60 mL/min/1.73 m² persisting for more than 3 months, and should be classified using both GFR categories (G1-G5) and albuminuria categories (A1-A3) to accurately assess risk and guide management decisions. 1
Definition and Classification of CKD
Diagnostic Criteria
- Definition: Kidney damage or GFR <60 mL/min/1.73 m² for ≥3 months, regardless of cause 2, 3
- Kidney damage indicators:
- Albuminuria (albumin-to-creatinine ratio >30 mg/g in 2 of 3 spot urine specimens)
- Pathological abnormalities
- Abnormalities in blood or urine composition
- Abnormalities on imaging tests 2
GFR Categories (G)
| GFR Category | GFR (mL/min/1.73 m²) | Description |
|---|---|---|
| G1 | ≥90 | Normal or high (with evidence of kidney damage) |
| G2 | 60-89 | Mildly decreased (with evidence of kidney damage) |
| G3a | 45-59 | Mildly to moderately decreased |
| G3b | 30-44 | Moderately to severely decreased |
| G4 | 15-29 | Severely decreased |
| G5 | <15 or dialysis | Kidney failure |
Albuminuria Categories (A)
| Category | Albumin-to-Creatinine Ratio (mg/g) | Description |
|---|---|---|
| A1 | <30 | Normal to mildly increased |
| A2 | 30-300 | Moderately increased |
| A3 | >300 | Severely increased |
Risk Assessment and Monitoring
Risk Prediction
- For CKD G3-G5, use externally validated risk equations to estimate absolute risk of kidney failure 2
- Risk thresholds for clinical decision-making:
- 5-year kidney failure risk of 3-5%: Consider nephrology referral
- 2-year kidney failure risk >10%: Consider multidisciplinary care
- 2-year kidney failure risk >40%: Begin preparation for kidney replacement therapy 2
Monitoring Frequency Based on Risk
| GFR Category | Albuminuria Category | Monitoring Frequency |
|---|---|---|
| G1-G2 | A1 | Annual |
| G3a | A1 | 1-2 times per year |
| G1-G2 | A2 | 1-2 times per year |
| G4-G5 | A1-A3 | 3-4 times per year |
| Any | A3 | 3-4 times per year |
Management Strategies
Blood Pressure Management
- For albuminuria <30 mg/24h: Target BP ≤140/90 mmHg
- For albuminuria ≥30 mg/24h: Target BP ≤130/80 mmHg 1
- First-line agents for patients with albuminuria >300 mg/24h: ACE inhibitors or ARBs 1
Lifestyle Modifications
- Physical activity: 150 minutes/week of moderate-intensity exercise, adjusted to cardiovascular tolerance 2, 1
- Diet: Plant-based "Mediterranean-style" diet with reduced ultra-processed foods 1
- Sodium intake: <2000 mg/day 1
- Protein intake: 0.8 g/kg body weight/day for adults with CKD G3-G5 1
- Weight management: Achieve optimal BMI; consider weight loss if obese 1
- Tobacco: Complete avoidance with referral to cessation programs as needed 1
Medication Management
Diabetes management:
- SGLT2 inhibitors when eGFR ≥20 mL/min/1.73 m² (continue until dialysis/transplantation)
- Metformin when eGFR ≥30 mL/min/1.73 m²
- Consider GLP-1 receptor agonists for additional glycemic control 1
Lipid management:
- Statin or statin/ezetimibe for adults ≥50 years with eGFR <60 mL/min/1.73 m²
- Consider statins for adults 18-49 years with coronary disease, diabetes, prior stroke, or 10-year CV risk >10% 1
Management of Complications
- Monitor and treat laboratory abnormalities associated with CKD:
- Anemia
- CKD-mineral and bone disorders
- Potassium disorders
- Metabolic acidosis (treat when bicarbonate <18 mmol/L) 1
Referral Criteria
Refer patients to nephrology with:
- eGFR <30 mL/min/1.73 m²
- Albuminuria ≥300 mg/24 hours
- Rapid decline in eGFR (>5 mL/min/1.73 m²/year)
- 5-year risk of end-stage renal disease >3-5% 1
Multidisciplinary Approach
Implement a team-based approach including:
- Nephrologist
- Primary care physician
- Endocrinologist (for diabetic patients)
- Dietitian
- Pharmacist
- Nurse
- Cardiologist (when needed) 1
Common Pitfalls to Avoid
- Relying solely on GFR for staging: Always include albuminuria assessment for comprehensive risk stratification
- Overlooking albuminuria in early CKD: Even with normal GFR, albuminuria indicates kidney damage and increased risk
- Inadequate monitoring frequency: Adjust monitoring based on both GFR and albuminuria categories
- Nephrotoxic medications: Avoid when possible to prevent acute kidney injury
- Delayed referral: Use risk prediction tools rather than waiting for advanced disease
The combined use of GFR and albuminuria categories provides a more accurate assessment of prognosis than either measure alone, allowing for more targeted interventions to slow disease progression and reduce mortality.