Management of Worsening GFR
For patients with worsening GFR labs indicating impaired renal function, implement a systematic approach focusing on blood pressure control with ACE inhibitors or ARBs, glycemic control, medication review, and timely nephrology referral to reduce mortality and improve quality of life.
Assessment and Classification
- Determine the severity and rate of GFR decline:
- Compare current eGFR with previous values (rapid progression defined as >5 mL/min/1.73m² decline per year) 1
- Classify CKD stage based on current GFR: G1: ≥90, G2: 60-89, G3a: 45-59, G3b: 30-44, G4: 15-29, G5: <15 mL/min/1.73m² 1
- Measure albuminuria/proteinuria (urine albumin-to-creatinine ratio) - critical for risk stratification 1
Immediate Interventions
1. Blood Pressure Control
- Target BP <130/80 mmHg for patients with proteinuria <1 g/day, and <125/75 mmHg for proteinuria >1 g/day 1
- First-line agents:
- For patients with albuminuria: ACE inhibitors or ARBs 2, 1
- Titrate to maximally tolerated doses 1
- Monitor serum creatinine and potassium within 7-14 days after initiation 1
- Note: An initial 10-20% increase in serum creatinine after starting ACE inhibitors is expected and should not prompt discontinuation 1, 3
2. Glycemic Control
- Optimize glucose control to reduce risk and slow progression of nephropathy 2
- Adjust antihyperglycemic medications based on kidney function 1:
3. Medication Review
- Review all medications for appropriate dosing in renal impairment 1
- Discontinue nephrotoxic medications:
Lifestyle Modifications
- Protein intake: Recommend 0.8 g/kg/day for patients with GFR <30 mL/min/1.73m² 2, 1
- Sodium restriction: <2 g/day to improve BP control 1
- Potassium restriction may be necessary to control serum potassium 1
- Weight management for overweight/obese patients 1
- Smoking cessation 1
- Regular physical activity 1
Monitoring and Follow-up
- Monitor eGFR and albuminuria at least annually, more frequently for advancing CKD stages 1
- Check serum potassium and renal function within 1-2 weeks of medication changes 1
- Monitor for complications:
- Hypertension
- Volume overload
- Electrolyte abnormalities
- Metabolic acidosis
- Anemia (check hemoglobin at least every 3 months) 1
- Metabolic bone disease
When to Refer to Nephrology
- eGFR falls below 30 mL/min/1.73m² 1
- Significant albuminuria (>300 mg/g) 1
- Rapid progression (>5 mL/min/1.73m² decline per year) 1
- Complications of CKD that are difficult to manage 1
- Consider earlier referral for patients with diabetes and kidney disease 2
Management of Acute Kidney Injury
- Identify and treat reversible causes:
- Volume depletion
- Obstruction
- Medication-related causes 1
- Temporarily discontinue RAS blockade and NSAIDs during acute illness 1
- Resume ACE inhibitors/ARBs after stabilization, as these medications provide long-term renoprotection 3
Preparation for Renal Replacement Therapy
- Discuss RRT options when eGFR <30 mL/min/1.73m² 1
- Consider kidney transplant evaluation if eligible 1
- Preserve veins suitable for potential future vascular access 1
Common Pitfalls to Avoid
- Discontinuing ACE inhibitors prematurely due to an initial increase in serum creatinine (up to 30% increase may be acceptable and actually predicts long-term renal stability) 3
- Failing to test for albuminuria, which is essential for CKD risk stratification 1
- Excessive fluid intake - contrary to common belief, high urine volume and low urine osmolality are associated with faster GFR decline 5
- Continuing nephrotoxic medications like NSAIDs 1
- Inadequate blood pressure control - intensive BP control (<130/80 mmHg) is more effective than conventional control in slowing progression 6