How to manage a patient with impaired renal function (decreased eGFR)?

Management of Patients with Decreased eGFR

For patients with decreased eGFR, implement a comprehensive approach including medication management, blood pressure control, lifestyle modifications, and appropriate referral to nephrology based on eGFR level and comorbidities to reduce morbidity and mortality.

Classification and Monitoring

• Chronic kidney disease (CKD) is defined as chronic abnormalities of kidney structure and function, with stages determined by eGFR levels 1:

  • Stage 1: eGFR ≥90 mL/min/1.73 m² with kidney damage
  • Stage 2: eGFR 60-89 mL/min/1.73 m² with kidney damage
  • Stage 3a: eGFR 45-59 mL/min/1.73 m² (mild to moderate decrease)
  • Stage 3b: eGFR 30-44 mL/min/1.73 m² (moderate to severe decrease)
  • Stage 4: eGFR 15-29 mL/min/1.73 m² (severe decrease)
  • Stage 5: eGFR <15 mL/min/1.73 m² or dialysis (kidney failure)

• All patients with diabetes should undergo initial screening for CKD at diagnosis and at least annually thereafter, including urine routine, urinary albumin/creatinine ratio (UACR), and serum creatinine for eGFR calculation 1

• Monitoring frequency should increase with CKD progression; patients with eGFR <60 mL/min/1.73 m² should have more frequent monitoring of renal function, electrolytes, and medication dosing 1

Referral to Nephrology

• Refer patients to nephrology services when eGFR <30 mL/min/1.73 m² (CKD stages 4-5) 1

• Additional referral criteria include:

  • Abrupt sustained fall in GFR or acute kidney injury
  • Significant albuminuria (ACR ≥300 mg/g or ≥30 mg/mmol)
  • Progressive CKD
  • Urinary abnormalities (red cell casts, RBC >20 per high power field)
  • Refractory hypertension (requiring 4+ antihypertensive agents)
  • Persistent electrolyte abnormalities
  • Recurrent nephrolithiasis
  • Hereditary kidney disease 1

• Consider interdisciplinary clinical programs for patients with eGFR <30 mL/min/1.73 m², complex comorbidities, or evidence of rapid progression 1

Medication Management

Metformin

• Metformin dosing based on eGFR 1, 2:
  • eGFR ≥45 mL/min/1.73 m²: No dose adjustment needed
  • eGFR 30-44 mL/min/1.73 m²: Use with caution, reduce dose, monitor renal function
  • eGFR <30 mL/min/1.73 m²: Contraindicated
  • Temporarily discontinue metformin at the time of or before iodinated contrast imaging procedures in patients with eGFR 30-60 mL/min/1.73 m²

SGLT2 Inhibitors

• SGLT2 inhibitors are recommended for patients with type 2 diabetes and CKD regardless of HbA1c level 1
• SGLT2 inhibitors reduce renal tubular glucose reabsorption, weight, blood pressure, intraglomerular pressure, and albuminuria, and slow GFR loss through mechanisms independent of glycemia 1
• Initial eGFR decline of 3-5 mL/min/1.73 m² is expected but stabilizes over time 1
• For eGFR <20 mL/min/1.73 m², GLP-1 receptor agonists are preferred, though dapagliflozin or canagliflozin can be continued if already prescribed 1

GLP-1 Receptor Agonists

• GLP-1 receptor agonists (dulaglutide, semaglutide, liraglutide) have shown renal protective effects and are preferred for patients with eGFR <20 mL/min/1.73 m² 1
• These agents reduce the risk of new or worsening nephropathy by 22-36% 1

Antihypertensive Medications

• ACE inhibitors or ARBs are preferred treatments for patients with diabetes, hypertension, and UACR >30 mg/g 1
• Target blood pressure <130/80 mmHg for patients with albuminuria and <140/90 mmHg for those without albuminuria 3
• Monitor serum potassium in patients with eGFR <60 mL/min/1.73 m² receiving ACE inhibitors, ARBs, or mineralocorticoid receptor antagonists 1

Dietary and Lifestyle Modifications

• Protein intake should be approximately 0.8 g/kg/day for patients with non-dialysis dependent CKD 1
• Higher protein intake (>20% of daily calories or >1.3 g/kg/day) is associated with increased albuminuria, more rapid kidney function loss, and cardiovascular mortality 1
• For patients on dialysis, higher protein intake may be necessary to prevent malnutrition 1
• Restrict dietary sodium to <2,300 mg/day to control blood pressure and reduce cardiovascular risk 1
• Individualize potassium restriction based on serum potassium levels, especially in patients with reduced eGFR 1
• Regular physical activity, particularly walking, and weight loss can slow CKD progression 3
• Smoking cessation and avoiding binge alcohol consumption are important to prevent CKD progression 3

Management of Complications

• Monitor and manage complications of CKD when eGFR falls below 60 mL/min/1.73 m² 1:

  • Elevated blood pressure
  • Volume overload
  • Electrolyte abnormalities
  • Metabolic acidosis
  • Anemia
  • Metabolic bone disease

• Consider renal replacement therapy (dialysis) for patients with eGFR <30 mL/min/1.73 m² 1

Special Considerations

• Avoid nephrotoxic medications (e.g., NSAIDs) in patients with decreased eGFR 1, 4
• Adjust medication dosages based on eGFR levels 1
• Be cautious with iodinated contrast agents, especially in patients with eGFR <60 mL/min/1.73 m² 2
• Even patients with diabetes and normoalbuminuria can experience progressive eGFR decline after moderate loss of kidney function, requiring close monitoring 5
• Rapid reduction in HbA1c may be associated with faster eGFR decline in the short term, requiring careful monitoring 6

Pitfalls and Caveats

• Do not discontinue RAAS blockers (ACE inhibitors, ARBs) or SGLT2 inhibitors solely due to an initial decline in eGFR, as this is often hemodynamic and stabilizes over time 7
• Do not reduce protein intake below 0.8 g/kg/day as it does not alter glycemic measures, cardiovascular risk, or the course of GFR decline 1
• Avoid using metformin in patients with eGFR <30 mL/min/1.73 m² due to increased risk of lactic acidosis 2
• Do not withhold immunosuppressive therapy based solely on low eGFR in cases of active glomerulonephritis with preserved renal parenchyma, significant acute tubular necrosis, and/or no significant fibrosis or atrophy 1