What is the management for a patient with an estimated Glomerular Filtration Rate (eGFR) of 29, indicating severe kidney impairment?

Management of eGFR 29 mL/min/1.73 m²

A patient with eGFR 29 mL/min/1.73 m² requires immediate nephrology referral, as this represents Stage 4 CKD (severely decreased kidney function) approaching the threshold for renal replacement therapy. 1

Immediate Actions

Nephrology Referral

• Refer immediately to nephrology for any patient with eGFR <30 mL/min/1.73 m², as consultation at this stage reduces costs, improves quality of care, and delays dialysis. 1
• At eGFR 29, the patient is approaching Stage 5 CKD, making preparation for renal replacement therapy urgent. 1

Monitoring Frequency

• Monitor creatinine, eGFR, urinary albumin excretion, and potassium twice yearly minimum for Stage 4 CKD. 1
• Increase monitoring to quarterly or more often if rapid progression occurs, new medications are initiated, or clinical status changes. 1
• Monitor electrolytes and renal function daily if the patient requires IV NaCl administration. 2

Screening for CKD Complications

At eGFR 29, complications of CKD become prevalent and require systematic evaluation 3:

• Screen for secondary hyperparathyroidism as part of CKD-mineral bone disease management by checking serum calcium, phosphate, PTH, and vitamin 25(OH)D. 3, 1
• Evaluate and correct metabolic acidosis, which commonly develops at this level of kidney function, by checking serum electrolytes. 3, 1
• Screen for anemia with hemoglobin and iron studies if indicated. 3
• Monitor blood pressure and volume status at every clinical contact, assessing for elevated blood pressure >140/90 mmHg and volume overload through history, physical examination, and weight. 3

Blood Pressure Management

• Target systolic BP <130 mmHg and diastolic BP <80 mmHg. 1
• Use ACE inhibitors or ARBs as first-line agents for blood pressure control and kidney protection. 1
• Important caveat: 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
• At eGFR 29, elimination half-life of ACE inhibitors like lisinopril becomes clinically important and requires dose adjustment. 4

Critical Medication Adjustments

Discontinue Immediately

• Metformin is contraindicated at eGFR <30 mL/min/1.73 m² and must be discontinued immediately. 1

Adjust Dosing

• Insulin: Reduce total daily dose by 35-50% due to decreased renal clearance and reduced gluconeogenesis. 1
• SGLT2 inhibitors (Canagliflozin): Maximum 100 mg daily; may continue for kidney and cardiovascular benefit until dialysis. 1
• ACE inhibitors/ARBs: Dose adjustment required as elimination becomes impaired when GFR falls below 30 mL/min. 4, 5

Avoid Dual RAS Blockade

• Do not combine ACE inhibitors with ARBs in patients with eGFR <30, as dual blockade increases risks of hyperkalemia, acute kidney injury, and hypotension without additional benefit. 5
• The VA NEPHRON-D trial demonstrated that combining losartan with lisinopril provided no additional benefit but increased incidence of hyperkalemia and acute kidney injury. 5

Fluid Management Precautions

• Consult nephrology before administering IV fluids to patients with eGFR 29, as they are at significantly increased risk of fluid overload and further kidney damage. 2
• Monitor daily for signs of fluid overload when IV fluids are necessary. 2
• Consider more frequent monitoring of renal function in patients requiring volume expansion. 2

Glycemic Management (if diabetic)

• 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
• Monitor HbA1c twice yearly, increasing to quarterly if not at target or therapy changes. 1

Preparation for Renal Replacement Therapy

• Begin patient education about the progressive nature of kidney disease and potential need for dialysis or transplantation. 1
• Discuss options for renal replacement therapy and consider vascular access planning. 1
• Note that eligibility for CAR-T cell therapy and many clinical trials requires eGFR >40-50 mL/min/1.73 m², making renal recovery efforts particularly important. 3

Medication Safety Considerations

• Monitor serum potassium closely when using ACE inhibitors, ARBs, or other potassium-sparing agents, as hyperkalemia risk is substantially elevated at this eGFR. 5
• Avoid NSAIDs (including COX-2 inhibitors), as they can cause deterioration of renal function, including acute renal failure, particularly in elderly or volume-depleted patients. 5
• Monitor lithium levels if the patient is on lithium, as ARBs increase serum lithium concentrations and toxicity risk. 5

Common Pitfalls to Avoid

• Do not delay nephrology referral—at eGFR 29, the patient is one stage away from end-stage renal disease. 1
• Do not continue metformin "just a little longer"—it is absolutely contraindicated at this eGFR. 1
• Do not assume small creatinine increases with ACE inhibitors/ARBs represent acute kidney injury—up to 30% increase 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. 2