What is the management plan for a patient with Chronic Kidney Disease (CKD) stage 3b?

Management of CKD Stage 3b

For patients with CKD stage 3b (GFR 30-44 mL/min/1.73m²), treatment should focus on blood pressure control with a target of <120 mmHg systolic when tolerated, using renin-angiotensin system inhibitors as first-line therapy, and adding SGLT2 inhibitors for patients with type 2 diabetes. 1

Blood Pressure Management

Target Blood Pressure

• Target systolic blood pressure of <120 mmHg when tolerated, using standardized office BP measurement 1
• Consider less intensive BP-lowering therapy in patients with:
  • Frailty
  • High risk of falls and fractures
  • Very limited life expectancy
  • Symptomatic postural hypotension 1

First-Line Medications

• Renin-angiotensin system inhibitors (RASi) - ACEi or ARB:
  • Recommended for patients with moderately to severely increased albuminuria (A2 and A3) with or without diabetes 1
  • Should be administered at the highest approved dose that is tolerated 1
  • Continue ACEi or ARB even when eGFR falls below 30 mL/min/1.73m² 1

Monitoring After RASi Initiation

• Check changes in BP, serum creatinine, and serum potassium within 2-4 weeks of initiation or dose increase 1
• Continue ACEi or ARB unless serum creatinine rises by more than 30% within 4 weeks following initiation or dose increase 1
• Hyperkalemia associated with RASi can often be managed by measures to reduce serum potassium rather than decreasing the dose or stopping RASi 1

Diabetes Management in CKD

• For patients with type 2 diabetes and CKD with eGFR ≥20 mL/min/1.73m², add an SGLT2 inhibitor 1
• Continue SGLT2i even if eGFR falls below 20 mL/min/1.73m² unless not tolerated or kidney replacement therapy is initiated 1
• Consider withholding SGLT2i during times of prolonged fasting, surgery, or critical medical illness (when patients may be at greater risk for ketosis) 1

Cardiovascular Risk Reduction

• Statin therapy is recommended for all adults ≥50 years with CKD regardless of GFR 2
• For adults 18-49 years with CKD, consider statin therapy if they have:
  • Known coronary disease
  • Diabetes mellitus
  • Prior ischemic stroke
  • Estimated 10-year risk of coronary death/MI >10% 2
• Maximize LDL reduction with appropriate statin dosing based on kidney function 2
• Atorvastatin 20mg daily can be considered as a starting dose (no dose adjustment required for kidney disease) 2

Nutritional Management

Phosphorus Management

• Adjust dietary phosphorus intake to maintain serum phosphate levels in the normal range 1
• Consider the bioavailability of phosphorus sources (animal, vegetable, additives) when making recommendations 1

Potassium Management

• Adjust dietary potassium intake to maintain serum potassium within the normal range 1
• Individualize dietary or supplemental potassium intake based on serum potassium levels 1

Sodium Intake

• Limit sodium intake to less than 2.3 g/day to:
  • Reduce blood pressure and improve volume control 1
  • Reduce proteinuria synergistically with pharmacologic interventions 1
  • Achieve better volume control and more desirable body weight 1

Calcium Intake

• For patients not taking active vitamin D analogs, prescribe total elemental calcium intake of 800-1,000 mg/day 1
• Adjust calcium intake with consideration of concurrent use of vitamin D analogs and calcimimetics 1

Anemia Management

• For patients with CKD and anemia:
  • Evaluate iron status before and during treatment 3
  • Administer supplemental iron therapy when serum ferritin is <100 mcg/L or transferrin saturation is <20% 3
  • Consider erythropoiesis-stimulating agents (ESAs) when hemoglobin is <10 g/dL 3
  • Target hemoglobin should not exceed 11 g/dL due to increased cardiovascular risks 3

Monitoring Frequency

• Monitor patients with CKD stage 3b at least every 6 months 1
• Monitoring should include:
  • Blood pressure
  • Serum creatinine/eGFR
  • Electrolytes (potassium, calcium, phosphate)
  • Albuminuria/proteinuria
  • Hemoglobin
  • Nutritional status

Referral to Nephrology

• Refer patients to a nephrologist if they have:
  • Rapid decline in eGFR
  • Persistent significant albuminuria (ACR >300 mg/g)
  • Resistant hypertension
  • Persistent abnormalities of serum potassium
  • Recurrent or extensive nephrolithiasis
  • Hereditary kidney disease 1

Common Pitfalls to Avoid

1. Discontinuing ACEi/ARB prematurely due to modest increases in serum creatinine
2. Failing to screen for and manage mineral bone disorders (calcium, phosphorus, PTH)
3. Targeting hemoglobin >11 g/dL with ESAs, which increases cardiovascular risks
4. Overlooking the importance of SGLT2 inhibitors in patients with type 2 diabetes
5. Not considering statin therapy for cardiovascular risk reduction
6. Inadequate monitoring of electrolytes, particularly potassium, in patients on RASi

By following this comprehensive approach to managing CKD stage 3b, progression to more advanced stages can be delayed and complications minimized, ultimately improving patient outcomes.