What is the management for a patient with impaired renal function, specifically a Glomerular Filtration Rate (GFR) of 15-30?

Management of Patients with GFR 15-30 mL/min/1.73 m²

Immediately refer to nephrology for any patient with eGFR <30 mL/min/1.73 m², as this represents Stage 4 CKD approaching end-stage renal disease, and early nephrology consultation reduces costs, improves quality of care, and delays dialysis. 1

Nephrology Referral and Renal Replacement Therapy Planning

• Urgent nephrology referral is mandatory at this GFR range unless the finding is stable and isolated with clear diagnosis in elderly patients with limited life expectancy 1
• Begin patient education immediately about the progressive nature of kidney disease and potential need for dialysis or transplantation 1
• Discuss options for renal replacement therapy (hemodialysis, peritoneal dialysis, or transplantation) and initiate vascular access planning 1
• Consider that kidney transplantation or home dialysis may optimally be performed before patients reach CKD stage 5 (GFR <15) 2
• Dialysis initiation should be considered when GFR falls below 15 mL/min/1.73 m², though certain complications may justify earlier initiation 1
• Specific indications for earlier dialysis include: uremic pericarditis, uremic symptoms affecting nutrition or quality of life, protein-energy malnutrition developing or persisting despite vigorous attempts to optimize intake with no apparent cause other than low nutrient intake 2, 1

Monitoring Frequency

• Monitor creatinine, eGFR, urinary albumin excretion, and potassium twice yearly minimum for Stage 4 CKD 1
• Increase monitoring frequency to quarterly or more often if rapid progression occurs, new medications are initiated, or clinical status changes 1
• Monitor HbA1c twice yearly in diabetic patients, increasing to quarterly if not at target or therapy changes 1
• Monitor blood pressure and volume status at every clinical contact, assessing for elevated BP >140/90 mmHg and volume overload 3

Screening for CKD Complications

• Screen for secondary hyperparathyroidism by checking serum calcium, phosphate, PTH, and vitamin 25(OH)D as part of CKD-mineral bone disease management 1, 3
• Evaluate and correct metabolic acidosis by checking serum electrolytes, which commonly develops at this level of kidney function 1, 3
• Screen for anemia with hemoglobin and iron studies if indicated 3

Blood Pressure Management

• Target systolic BP <130 mmHg and diastolic BP <80 mmHg 1, 3
• Use ACE inhibitors or ARBs as first-line agents for blood pressure control and kidney protection 1, 3
• Small elevations in serum creatinine (up to 30% from baseline) with ACE inhibitors or ARBs should not be confused with acute kidney injury and do not require discontinuation 3
• Continue ACE inhibitors/ARBs even in advanced CKD for cardiovascular and renal protection, as renoprotection is maximized with long-lasting treatment and may result in GFR stabilization and definitive prevention of ESRD 4
• Avoid dual blockade of the renin-angiotensin system (combining ACE inhibitors with ARBs or aliskiren), as this increases risks of hypotension, hyperkalemia, and acute kidney injury without additional benefit 5

Critical Medication Adjustments

Antidiabetic Medications

• Metformin: CONTRAINDICATED at eGFR <30 mL/min/1.73 m² - discontinue immediately 2, 1, 3
• Insulin: Reduce total daily dose by 35-50% due to decreased renal clearance and reduced gluconeogenesis 1, 3
• Canagliflozin: Maximum 100 mg daily; may continue for kidney and cardiovascular benefit until dialysis 2, 1, 3
• Dapagliflozin: Not recommended for glucose lowering at eGFR <45, but may use 10 mg for HF or CKD indications if eGFR 25-45; initiation not recommended if eGFR <25 2
• Sitagliptin: 25 mg daily 1
• Alogliptin: 6.25 mg daily 1
• Saxagliptin: Maximum 2.5 mg daily if eGFR ≤45 mL/min/1.73 m² 1
• Glimepiride: Consider alternative if eGFR <15 mL/min/1.73 m² 1
• Glyburide: Avoid use 1
• Exenatide: Contraindicated at CrCl <30 2, 1
• Lixisenatide: Avoid if eGFR <15 mL/min/1.73 m² 2, 1
• Liraglutide, dulaglutide, semaglutide: No dose adjustment required, but monitor eGFR when initiating or escalating doses 2, 1

ACE Inhibitors/ARBs

• Losartan: No dose adjustment necessary in renal impairment unless patient is also volume depleted 5
• Lisinopril: Above GFR 30 mL/min, elimination half-life is little changed; below 30 mL/min, dose adjustment becomes clinically important 6
• Monitor serum potassium when using ACE inhibitors/ARBs, as coadministration with other drugs that raise potassium may result in hyperkalemia 5
• Monitor renal function periodically when combining ACE inhibitors/ARBs with NSAIDs, as this may result in deterioration of renal function, including possible acute renal failure 5

Glycemic Management (for Diabetic Patients)

• Target HbA1c <7.0% for most patients, though higher targets may be appropriate for those with severe comorbidities, limited life expectancy, or high hypoglycemia risk 1

Fluid Management Precautions

• Consult nephrology before administering IV fluids to patients with eGFR 15-30, as they are at significantly increased risk of fluid overload and further kidney damage 1, 7
• Monitor daily for signs of fluid overload when IV fluids are necessary 1, 7
• Monitor electrolytes and renal function daily if patient requires IV NaCl administration 7, 3

Common Pitfalls to Avoid

• Do not delay nephrology referral - at GFR 15-30, the patient is approaching or at end-stage renal disease 1, 3
• Do not continue metformin "just a little longer" - it is absolutely contraindicated at eGFR <30 1, 3
• Do not assume small creatinine increases (up to 30%) with ACE inhibitors/ARBs represent acute kidney injury - this is acceptable and does not predict worse outcomes 3
• Do not administer IV fluids liberally without nephrology input - these patients have severely impaired ability to handle volume loads 1, 7
• Do not discontinue ACE inhibitors/ARBs prematurely - renoprotection is maximized with long-lasting treatment and may prevent ESRD 4
• Do not combine ACE inhibitors with ARBs - dual RAS blockade increases risks without additional benefit 5