How to manage a patient with decreased Glomerular Filtration Rate (GFR)?

Management of Decreased Glomerular Filtration Rate (GFR)

For patients with decreased GFR, implement a comprehensive management plan that includes blood pressure control with ACE inhibitors or ARBs, glycemic control in diabetics, sodium-glucose cotransporter 2 (SGLT2) inhibitors when appropriate, metabolic abnormality correction, and lifestyle modifications to slow CKD progression and reduce cardiovascular risk. 1, 2

Assessment and Monitoring

• Assess GFR and albuminuria at least annually in all CKD patients, more frequently in those at higher risk of progression 2

• Recognize that small fluctuations in GFR are common and not necessarily indicative of progression 2

• Define CKD progression based on:

  • Decline in GFR category
  • Sustained decline in eGFR >5 ml/min/1.73 m²/year
  • 25% or greater drop in eGFR from baseline 2

• Monitor for complications of CKD:

  • Serum electrolytes (especially potassium)
  • Acid-base status (bicarbonate)
  • Calcium and phosphorus
  • Parathyroid hormone (iPTH)
  • Hemoglobin 1

Blood Pressure Management

• Target blood pressure: <130/80 mmHg 1
• First-line therapy: ACE inhibitor or ARB
  • Start at low dose and monitor serum creatinine and potassium within 7-14 days after initiation
  • Avoid combining ACE inhibitors with ARBs (increases risk of hyperkalemia without additional benefit) 1, 3
  • Temporarily stop ACE inhibitor/ARB during periods of volume depletion (illness with vomiting/diarrhea) 1

Glycemic Control and SGLT2 Inhibitors

• For patients with type 2 diabetes and CKD, use SGLT2 inhibitors to reduce CKD progression and cardiovascular events if eGFR ≥20 mL/min/1.73 m² 2
• Target HbA1c <7% for diabetic patients 1

Metabolic Abnormality Management

• Monitor serum bicarbonate every 3 months and maintain ≥22 mmol/L 1, 2
• Monitor calcium, phosphorus (every 3 months), and iPTH (at least once, and every 3 months if abnormal) 1
• If phosphorus ≥4.5 mg/dL or iPTH ≥100 pg/mL:
  • Prescribe low phosphorus diet (800-1000 mg/day)
  • Start phosphate binders if phosphorus remains elevated 1
• Check vitamin D status and supplement if deficient 1

Anemia Management

• Check hemoglobin at least every 3 months
• If hemoglobin <12 g/dL (women) or <13 g/dL (men), perform complete anemia workup including iron studies
• Treat iron deficiency if identified
• Consider erythropoietin or analogue if anemia persists despite iron therapy 1

Nutritional Management

• Monitor nutritional status by measuring body weight and serum albumin every 3 months
• For patients with non-dialysis-dependent stage 3 or higher CKD, aim for dietary protein intake of 0.8 g/kg body weight per day 2, 1
• For patients on dialysis, consider higher protein intake to prevent protein energy wasting 2
• Sodium restriction to <2 grams per day 1

Cardiovascular Risk Reduction

• Consider all CKD patients at increased risk for cardiovascular disease 2
• Monitor lipids and treat dyslipidemia (target LDL <100 mg/dL) 1
• Consider antiplatelet therapy for atherosclerotic risk reduction, balancing bleeding risk 2
• Interpret cardiac biomarkers (BNP/NT-proBNP, troponin) with caution in CKD patients 2

Nephrotoxin Avoidance

• Review all medications for nephrotoxicity
• Avoid NSAIDs, especially in elderly or volume-depleted patients 3
• Use caution with radiocontrast media; provide adequate hydration before procedures 2
• Adjust medication dosages based on current kidney function 1

When to Refer to Nephrology

• eGFR <30 mL/min/1.73 m² 2
• Rapid progression (sustained decline in eGFR >5 mL/min/1.73 m²/year) 2
• Persistent significant albuminuria (>300 mg/g) 2
• Difficult management issues (resistant hypertension, electrolyte abnormalities) 2
• Uncertainty about the etiology of kidney disease 2

Preparation for Renal Replacement Therapy

• Discuss RRT options when eGFR <30 mL/min/1.73 m² (hemodialysis, peritoneal dialysis, transplantation) 1
• Consider transplant evaluation if eligible
• Preserve veins suitable for potential future vascular access
• Arrange for vascular access creation if hemodialysis is planned 1

Lifestyle Modifications

• Regular physical activity (at least 150 minutes of moderate exercise weekly)
• Smoking cessation
• Weight management for overweight or obese patients
• Consider Mediterranean or DASH eating pattern 1

By implementing this comprehensive approach to managing decreased GFR, you can slow CKD progression, reduce cardiovascular risk, and improve patient outcomes. Early intervention is key to preserving kidney function and preventing complications.