What are the management and treatment recommendations for a patient with severely impaired renal function, indicated by an eGFR of 13, and a likely history of diabetes and hyperuricemia?

Management of Severely Impaired Renal Function (eGFR 13)

With an eGFR of 13 mL/min/1.73 m², you must immediately refer this patient to nephrology for urgent evaluation and preparation for renal replacement therapy, as this represents Stage 5 CKD (kidney failure) requiring imminent dialysis planning or transplant evaluation. 1

Immediate Nephrology Referral - Non-Negotiable

• All patients with eGFR <30 mL/min/1.73 m² require nephrology referral, and at eGFR 13, this patient is well beyond that threshold and approaching end-stage renal disease (ESRD). 1
• Early nephrology consultation when eGFR falls below 30 mL/min/1.73 m² has been proven to reduce costs, improve quality of care, and delay dialysis initiation. 1
• Late referral (waiting until dialysis is imminent) is associated with increased mortality after dialysis initiation, making urgent referral at this eGFR critical. 2, 3
• The nephrologist will initiate discussion of renal replacement therapy options (hemodialysis, peritoneal dialysis, or kidney transplantation) and begin vascular access planning if hemodialysis is anticipated. 1, 4

Essential Diagnostic Workup

• Measure urine albumin-to-creatinine ratio (UACR) on a spot urine sample to assess degree of proteinuria, which helps determine etiology (likely diabetic nephropathy if UACR ≥300 mg/g with diabetes history) and guides treatment intensity. 1, 5, 6
• Obtain complete metabolic panel to screen for hyperkalemia, metabolic acidosis (serum bicarbonate), hyperphosphatemia, all of which are common and dangerous complications at this level of kidney function. 1, 6, 7
• Check complete blood count to assess for anemia of CKD, which is nearly universal at eGFR <30 mL/min/1.73 m². 6, 7
• Measure serum calcium, phosphate, intact parathyroid hormone (PTH), and 25-hydroxyvitamin D to evaluate for CKD-mineral bone disorder. 6, 7

Blood Pressure Management

• Target blood pressure <140/90 mmHg as a general recommendation for all patients with diabetes and CKD to reduce cardiovascular mortality and slow CKD progression. 1
• Consider lower targets (<130/80 mmHg) if the patient has significant albuminuria (≥300 mg/day), as patients with heavy proteinuria may benefit from more aggressive blood pressure control. 1
• Continue ACE inhibitor or ARB therapy even at eGFR 13 mL/min/1.73 m², as these medications reduce progression to ESRD in patients with established CKD and albuminuria. 1
• You may need to reduce the dose or discontinue ACE inhibitor/ARB only if the patient develops symptomatic hypotension, uncontrolled hyperkalemia despite medical treatment, or to reduce uremic symptoms while treating kidney failure (eGFR <15). 1
• Never combine ACE inhibitors with ARBs, as this increases adverse events (hyperkalemia, acute kidney injury) without additional cardiovascular or kidney benefits. 1

Glycemic Management in Advanced CKD

• Metformin is absolutely contraindicated at eGFR <30 mL/min/1.73 m² due to risk of lactic acidosis and must be discontinued immediately. 1
• SGLT2 inhibitors (empagliflozin, dapagliflozin) can be continued if already initiated and well-tolerated, even at eGFR <20 mL/min/1.73 m², though they have minimal glucose-lowering effects at this level and are used primarily for cardiovascular and kidney protection. 1, 8
• Do not initiate SGLT2 inhibitors at eGFR 13 unless the primary goal is cardiovascular benefit in a patient with heart failure, as glucose-lowering efficacy is negligible at this GFR. 1
• GLP-1 receptor agonists (liraglutide, semaglutide, dulaglutide) are preferred for glucose control at eGFR 13, as they have been studied down to eGFR 15 mL/min/1.73 m², retain glucose-lowering potency, and reduce cardiovascular events. 1
• Use caution with GLP-1 receptor agonists if the patient is malnourished or at risk for malnutrition, as they cause nausea, vomiting, and weight loss. 1
• Insulin and short-acting sulfonylureas are often necessary for glucose control when other medications are contraindicated or insufficient, but both increase hypoglycemia risk, which is heightened in advanced CKD. 1

Management of CKD Complications

Hyperkalemia

• Monitor serum potassium closely, as hyperkalemia is common at eGFR <30 mL/min/1.73 m². 1
• Avoid high-potassium foods (processed foods, salt substitutes), but do not unnecessarily restrict fruits and vegetables unless potassium is persistently elevated. 1
• If hyperkalemia develops despite dietary modification, consider potassium binders (patiromer, sodium zirconium cyclosilicate) rather than discontinuing ACE inhibitor/ARB. 1

Metabolic Acidosis

• Consider pharmacological treatment (sodium bicarbonate) if serum bicarbonate falls <18 mmol/L, as acidosis at this level can worsen anorexia, protein wasting, and bone disease. 1
• Monitor treatment to ensure serum bicarbonate does not exceed the upper limit of normal and does not adversely affect blood pressure, potassium, or fluid status. 1

Anemia

• Evaluate for anemia of CKD and consider erythropoiesis-stimulating agents (ESAs) and iron supplementation per nephrology guidance. 6, 7

Mineral Bone Disorder

• Manage hyperphosphatemia with dietary phosphate restriction and phosphate binders if needed. 6, 7
• Treat vitamin D deficiency and secondary hyperparathyroidism per nephrology recommendations. 6, 7

Hyperuricemia Management

• Do not treat asymptomatic hyperuricemia with urate-lowering therapy (allopurinol, febuxostat) in the absence of gout or tophi, as newer data do not support targeting hyperuricemia for kidney protection. 1
• If the patient has symptomatic gout, treat with urate-lowering therapy, but this is for symptom control, not to slow CKD progression. 1

Cardiovascular Risk Reduction

• Initiate or continue high-intensity statin therapy (atorvastatin 40-80 mg daily) for cardiovascular risk reduction, as CKD patients have 5-10 times higher cardiovascular mortality risk. 5, 6
• Consider antiplatelet therapy (aspirin 81 mg daily) if the patient has established cardiovascular disease and no contraindications. 2

Dietary Modifications

• Restrict protein intake to 0.8 g/kg/day to slow CKD progression and reduce uremic symptoms, but avoid protein intake <0.6 g/kg/day due to malnutrition risk. 1, 5
• Restrict sodium to <2.0 g/day to enhance blood pressure control, reduce proteinuria, and improve diuretic efficacy if volume overload is present. 5, 2

Medication Safety and Deprescribing

• Immediately discontinue all nephrotoxic medications, including NSAIDs, aminoglycosides, and any other nephrotoxins. 5, 6, 7
• Review all medications and adjust dosing based on eGFR, as many drugs (antibiotics, oral hypoglycemics, anticoagulants) require dose reduction or are contraindicated at eGFR <15 mL/min/1.73 m². 1, 7
• Consider deprescribing medications with narrow therapeutic windows or high risk of adverse effects in advanced CKD. 1

Monitoring Frequency

• Monitor eGFR, electrolytes (potassium, bicarbonate), and hemoglobin every 2-4 weeks until stable, then monthly, as rapid changes can occur at this level of kidney function. 5
• Monitor UACR every 3 months if ≥300 mg/g to assess response to therapy. 5

Critical Pitfalls to Avoid

• Do not delay nephrology referral under any circumstances at eGFR 13, as this patient needs urgent preparation for renal replacement therapy. 1, 2
• Do not discontinue ACE inhibitor/ARB for creatinine increases <30% in the absence of volume depletion or hyperkalemia, as this is expected and acceptable. 1, 5
• Do not continue metformin at eGFR <30 mL/min/1.73 m², as it is absolutely contraindicated due to lactic acidosis risk. 1
• Do not rely on serum creatinine alone; always calculate eGFR using validated equations (CKD-EPI 2021) for accurate assessment. 5, 6