What are the stages of Chronic Kidney Disease (CKD) and their corresponding treatments?

Stages of Chronic Kidney Disease and Their Treatments

Chronic Kidney Disease (CKD) is classified into five stages based on estimated glomerular filtration rate (eGFR) and evidence of kidney damage, with specific treatment approaches required for each stage to reduce morbidity and mortality. 1

Definition and Staging of CKD

CKD is defined as abnormalities of kidney structure or function present for >3 months, characterized by decreased GFR and/or evidence of kidney damage 1.

CKD Staging System:

Stage	Description	eGFR (mL/min/1.73 m²)	Treatment Focus
1	Normal or increased GFR with kidney damage	≥90	Diagnosis and risk reduction
2	Slightly decreased GFR with kidney damage	60-89	Slowing progression
3a	Mild to moderate GFR decrease	45-59	Evaluating/treating complications
3b	Moderate to severe GFR decrease	30-44	Evaluating/treating complications
4	Severe GFR decrease	15-29	Preparation for renal replacement
5	Kidney failure	<15 or dialysis	Renal replacement therapy

Note: Kidney damage is defined as albuminuria (UACR ≥30 mg/g) or abnormalities in pathological, urine, blood, or imaging examinations. 1

Treatment Approaches by Stage

Stages 1-2 (eGFR ≥60 mL/min/1.73 m²)

• Risk factor management:
  • Blood pressure control (target varies by comorbidities)
  • Glycemic control in diabetic patients
  • Lifestyle modifications (smoking cessation, weight management, exercise)
  • Dietary sodium restriction
• Medication management:
  • ACEIs or ARBs for patients with hypertension and albuminuria (UACR >30 mg/g) 1
  • Regular monitoring of kidney function (at least annual UACR and eGFR) 1

Stages 3a-3b (eGFR 30-59 mL/min/1.73 m²)

• All treatments from earlier stages plus:
  • More frequent monitoring (every 3-6 months)
  • Evaluation and management of CKD complications:
    • Anemia assessment
    • Bone mineral disorders evaluation
    • Metabolic acidosis correction
  • Medication dose adjustments
  • Avoidance of nephrotoxic agents
  • Protein intake of approximately 0.8 g/kg/day 1

Stage 4 (eGFR 15-29 mL/min/1.73 m²)

• All treatments from earlier stages plus:
  • Preparation for renal replacement therapy
  • Vascular access planning if hemodialysis anticipated
  • Education about treatment options (hemodialysis, peritoneal dialysis, transplantation)
  • More aggressive management of complications:
    • Anemia (consider erythropoiesis-stimulating agents when appropriate) 2
    • Mineral bone disorders
    • Electrolyte imbalances
  • Frequent monitoring (every 1-3 months)

Stage 5 (eGFR <15 mL/min/1.73 m²)

• Renal replacement therapy:
  • Dialysis (hemodialysis or peritoneal dialysis)
  • Kidney transplantation evaluation
  • Comprehensive management of uremic complications
  • Nutritional support (protein intake may be slightly higher in patients on dialysis) 1

Key Complications Requiring Management

1. Cardiovascular disease - Leading cause of mortality in CKD patients 3

   • Aggressive management of traditional risk factors
   • Consider cardiovascular risk in medication selection

2. Anemia

   • Iron status evaluation before and during treatment
   • ESAs for selected patients with careful hemoglobin monitoring
   • Target hemoglobin <11 g/dL when using ESAs 2

3. Mineral bone disorders

   • Monitor calcium, phosphorus, PTH
   • Phosphate binders, vitamin D analogs as appropriate

4. Metabolic acidosis

   • Bicarbonate supplementation when appropriate

5. Hypertension

   • ACEIs or ARBs preferred for patients with albuminuria
   • Multiple agents often required

Common Pitfalls to Avoid

1. Overtreatment of anemia - Targeting hemoglobin >11 g/dL with ESAs increases mortality and cardiovascular events 2

2. Medication errors - Failure to adjust medication dosages for declining kidney function

3. Late referral - Delaying nephrology consultation until advanced stages

4. Nephrotoxic medications - NSAIDs, certain antibiotics, and contrast agents can accelerate kidney damage

5. Inadequate preparation for renal replacement - Failing to plan for dialysis access placement in advance

6. Overlooking non-traditional risk factors - Inflammation, oxidative stress, and uremic toxins contribute to morbidity and mortality 3

Remember that early identification and management of CKD can significantly slow progression and reduce complications. Regular monitoring of kidney function and albuminuria is essential for all patients with risk factors for kidney disease.