Initial Management of Low eGFR (Impaired Renal Function)
Patients with low eGFR (estimated glomerular filtration rate) should be referred to a nephrologist when eGFR falls below 30 mL/min/1.73m², or earlier if there is significant albuminuria (>1 g/day), rapid progression, or complications of chronic kidney disease. 1, 2
Assessment and Classification
First, determine the severity of kidney dysfunction using eGFR:
| CKD Stage | Description | eGFR (mL/min/1.73 m²) |
|---|---|---|
| 1 | Normal GFR with kidney damage | ≥90 |
| 2 | Mild decrease in GFR | 60-89 |
| 3a | Mild to moderate decrease | 45-59 |
| 3b | Moderate to severe decrease | 30-44 |
| 4 | Severe decrease | 15-29 |
| 5 | Kidney failure | <15 or dialysis |
Initial Management Steps
1. Medication Review and Adjustment
- Stop nephrotoxic medications, particularly NSAIDs 2
- Adjust medication dosages based on current kidney function 2
- Review all medications for appropriate dosing in renal impairment 1
- For patients with diabetes, consider:
2. Blood Pressure Management
- Target blood pressure <130/80 mmHg 1, 2
- Initiate ACE inhibitors or ARBs for patients with albuminuria (>300 mg/g) 1
3. Dietary Modifications
- Protein intake: Approximately 0.8 g/kg/day for patients with diabetic kidney disease 1, 2
- Sodium restriction: <2 g/day to improve blood pressure control 1, 2
- Potassium restriction: May be necessary to control serum potassium 1
4. Screening for Complications
Monitor for common complications of CKD:
| Complication | Evaluation |
|---|---|
| Hypertension | Blood pressure, weight |
| Volume overload | Physical examination, weight |
| Electrolyte abnormalities | Serum electrolytes |
| Metabolic acidosis | Serum electrolytes |
| Anemia | Hemoglobin, iron studies if indicated |
| Metabolic bone disease | Calcium, phosphate, PTH, vitamin D |
5. Surveillance and Monitoring
- Regular monitoring of eGFR and albuminuria at least annually 1
- Serum potassium monitoring for patients on ACE inhibitors, ARBs, or diuretics 1
- Frequency of monitoring should increase with advancing CKD stages:
- Stage 3: Every 6-12 months
- Stage 4: Every 3-5 months
- Stage 5: Every 1-3 months 1
6. Planning for Advanced Disease
- Discuss renal replacement therapy options when eGFR <30 mL/min/1.73m² 1, 2
- Consider referral for kidney transplant evaluation if eligible 2
- Preserve veins suitable for potential future vascular access 2
- Consider palliative approach for patients with limited life expectancy or severe comorbidities 3
Special Considerations
Acute Kidney Injury (AKI)
- Distinguish between CKD and AKI or AKI superimposed on CKD
- Identify and treat reversible causes (volume depletion, obstruction, medications) 1
- Temporary discontinuation of RAS blockade and NSAIDs may be necessary during acute illness 1
Diabetes Management
- Well-controlled blood glucose may delay progression of kidney dysfunction 1
- Adjust antihyperglycemic medications based on kidney function 1
- Consider cardiovascular and kidney benefits of medications beyond glycemic control 1
Common Pitfalls to Avoid
- Don't discontinue ACE inhibitors/ARBs prematurely due to an initial 10-20% increase in serum creatinine 2
- Don't continue nephrotoxic medications like NSAIDs 2
- Don't overlook hyperkalemia risk, especially in elderly patients taking RAAS inhibitors 2
- Don't use concomitant potassium supplements with potassium-sparing medications 2
- Don't overlook cardiovascular risk reduction in CKD patients 2
By following these steps, you can effectively manage patients with impaired renal function and potentially slow the progression of kidney disease while reducing complications.