What is the best management approach for a patient with Chronic Kidney Disease (CKD) and a Glomerular Filtration Rate (GFR) of 36?

Management of CKD with GFR 36 mL/min/1.73 m²

This patient has Stage 3b CKD (GFR 30-44 mL/min/1.73 m²) and requires immediate nephrology referral, initiation of RAAS blockade if albuminuria is present, quarterly monitoring of kidney function and metabolic parameters, and aggressive cardiovascular risk reduction. 1, 2

Immediate Nephrology Referral

Refer to nephrology now—GFR 36 mL/min/1.73 m² meets the threshold for specialist involvement. 1, 2

• The American College of Physicians recommends nephrology referral when eGFR falls below 45 mL/min/1.73 m², and this patient at 36 mL/min/1.73 m² is already well into Stage 3b CKD 2
• Late referral (waiting until GFR <30) is associated with increased mortality after dialysis initiation, making timely referral at this stage critical 2
• Patients with GFR <30 mL/min/1.73 m² (Stage 4) require formal nephrology consultation and ongoing care management, but referral at GFR 36 allows for earlier intervention 1

Assess Albuminuria Status Immediately

Measure urinary albumin-to-creatinine ratio (ACR) if not already done, as this determines treatment intensity and progression risk 1, 2

• If ACR ≥30 mg/g: Start ACE inhibitor or ARB immediately (Grade 1B recommendation from KDIGO) 1, 2
• If ACR ≥300 mg/g: This patient is at very high risk for progression and cardiovascular events—RAAS blockade is mandatory 1
• Monitor for up to 30% increase in serum creatinine after starting ACE inhibitor/ARB, which is expected and acceptable unless volume depletion is present 1, 2

Common pitfall: Do not discontinue RAAS blockade if creatinine rises <30% after initiation—this is an expected hemodynamic effect, not nephrotoxicity 1, 2

Blood Pressure Management

Target blood pressure ≤130/80 mmHg for patients with CKD and albuminuria 2

• For patients >65 years, target systolic BP 130-139 mmHg, avoiding <120 mmHg 2
• ACE inhibitors or ARBs are first-line agents if albuminuria is present (ACR >30 mg/g) 1, 2
• Calcium channel blockers may be considered as first-line agents due to mechanistic advantage of blocking CNI-induced vasoconstriction, though this is primarily relevant in transplant recipients 1

Quarterly Monitoring Protocol

Schedule clinic visits every 3 months with comprehensive laboratory assessment. 2, 3, 4

At each 3-month visit, obtain:

• eGFR (using CKD-EPI equation) to track progression 2, 4
• Urinary albumin-to-creatinine ratio (ACR) to monitor proteinuria 2, 4
• Serum electrolytes (sodium, potassium) to detect imbalances requiring intervention 2, 4
• Serum bicarbonate to screen for metabolic acidosis (target ≥22 mmol/L) 2, 4
• Calcium and phosphorus to assess mineral metabolism 4
• Hemoglobin to screen for anemia 4
• Blood pressure measurement 4
• Body weight and serum albumin to monitor nutritional status 4

Additional monitoring every 3-6 months:

• Parathyroid hormone (PTH) if phosphorus control requires intervention (target intact PTH <100 pg/mL) 2, 4
• Lipid panel (target LDL <100 mg/dL) 2, 4
• Check 25(OH) vitamin D if PTH is elevated 4

Cardiovascular Risk Reduction

Prioritize cardiovascular risk reduction as aggressively as kidney-protective measures—the vast majority of Stage 3 CKD patients die from cardiovascular causes, not progression to ESRD. 2

• Initiate statin therapy: For adults ≥50 years with eGFR <60 mL/min/1.73 m² (Stage 3a-5), use a statin or statin/ezetimibe combination (Grade 1A recommendation) 1
• Target LDL <100 mg/dL and non-HDL cholesterol <130 mg/dL 4
• Consider aspirin 81 mg daily for secondary prevention if established cardiovascular disease is present 1
• Sodium restriction to <2 g/day to improve blood pressure control and reduce proteinuria 2
• Smoking cessation and exercise 30 minutes 5 times weekly 2

SGLT2 Inhibitor Consideration (If Diabetic)

If this patient has type 2 diabetes, initiate an SGLT2 inhibitor to reduce CKD progression and cardiovascular events 1

• SGLT2 inhibitors are recommended for eGFR ≥20 mL/min/1.73 m² with urinary albumin ≥200 mg/g creatinine (Grade 1A) 1
• Also recommended for eGFR ≥20 mL/min/1.73 m² with urinary albumin ranging from normal to 200 mg/g creatinine (Grade 1B) 1
• Target HbA1c ≤7.0% (or ≤8.0% if elderly with hypoglycemia risk) 2

Medication Review and Nephrotoxin Avoidance

Review all medications at each visit for necessary dose adjustments based on current eGFR. 2, 5

• Metformin: At GFR 36 mL/min/1.73 m², metformin is NOT contraindicated but requires careful monitoring 6
  • Metformin is contraindicated only when eGFR <30 mL/min/1.73 m² 6
  • Initiation is not recommended for eGFR 30-45 mL/min/1.73 m², but continuation is acceptable with benefit-risk assessment 6
  • Discontinue metformin before iodinated contrast procedures and restart 48 hours after if renal function is stable 6
• Avoid or minimize NSAIDs, which are nephrotoxic at this GFR level 2, 5
• Many antibiotics and oral hypoglycemic agents require dose adjustment at this eGFR level 2, 5
• Hold or reduce CNI therapy (if applicable) pre- and post-contrast exposure 1

Dietary Interventions

• Dietary protein intake should target 0.8 g/kg/day for patients with Stage 3b CKD 1
• Sodium restriction to <2 g/day improves blood pressure control, reduces proteinuria, and slows GFR decline 1, 2
• Limit intake of foods rich in bioavailable potassium (especially processed foods) if hyperkalemia develops 1
• Consider oral bicarbonate supplementation if serum bicarbonate <22 mmol/L to slow CKD progression 1
• Plant-based "Mediterranean-style" diet in addition to lipid-modifying therapy reduces cardiovascular risk 1

Define Progression Criteria

Rapid kidney function decline is defined as ≥30% decrease in eGFR over 2 years, or change in eGFR category plus ≥25% decline. 2

• Rising ACR suggests progression even if eGFR is stable 2
• If progression is documented, intensify nephrology involvement and consider earlier preparation for renal replacement therapy 2

Vaccination and Infection Prevention

• Administer annual influenza vaccine (Grade 1B) 1
• Administer polyvalent pneumococcal vaccine with revaccination within 5 years (Grade 1B) 1
• Immunize against hepatitis B and confirm response by serological testing (Grade 1B) 1

Prepare for Future Renal Replacement Therapy

At GFR 36 mL/min/1.73 m², begin discussing renal replacement therapy options 4

• Preserve veins suitable for vascular access if hemodialysis is anticipated (avoid venipuncture in non-dominant forearm) 4
• Consider referral for transplant evaluation if appropriate 4
• Educate patient on dialysis modalities (hemodialysis vs. peritoneal dialysis) and transplantation 4