Referral Guidelines for Nephrology

Primary Indications for Nephrology Referral

• The American Journal of Kidney Diseases recommends referral to nephrology when patients have an eGFR <30 mL/min/1.73 m², significant albuminuria (>1 g/day), or rapid decline in kidney function 1, 2
• Patients with an abrupt sustained decrease in eGFR >20% after excluding reversible causes should be referred to nephrology 3, 4
• The American Journal of Kidney Diseases suggests referral for patients with rapid progression of CKD (decline in eGFR >5 mL/min/1.73 m² per year) 2, 5
• Patients with persistent proteinuria with protein excretion >1 g/day (ACR ≥60 mg/mmol or PCR ≥100 mg/mmol) should be referred to nephrology 4, 2
• The American Journal of Kidney Diseases recommends referral for patients with urinary red cell casts or RBC >20 per high power field sustained and not readily explained 1, 2
• Patients with hypertension refractory to treatment with 4 or more antihypertensive agents should be referred to nephrology 1, 2
• The American Journal of Kidney Diseases suggests referral for patients with persistent abnormalities of serum potassium 1, 2
• Patients with recurrent or extensive nephrolithiasis should be referred to nephrology 1, 2
• The American Journal of Kidney Diseases recommends referral for patients with hereditary kidney disease 1, 2

Special Considerations

• The American Journal of Kidney Diseases and Diabetes Care recommend referring patients with diabetes and eGFR <30 mL/min/1.73 m² 6, 7
• Patients with diabetes who have persistent albuminuria despite optimal treatment should be considered for referral to nephrology 7, 8
• The American Journal of Kidney Diseases and Diabetes Care suggest considering referral for patients with diabetes who have difficult management of hypertension or electrolyte disturbances 7, 9
• Patients with diabetes who have uncertain etiology of kidney disease (absence of retinopathy, heavy proteinuria, active urine sediment) should be considered for referral to nephrology 8, 10

Planning for Renal Replacement Therapy

• The American Journal of Kidney Diseases recommends referring patients with progressive CKD in whom the risk of kidney failure within 1 year is 10-20% or higher 3, 4

Acute Kidney Injury (AKI)

• The American Journal of Kidney Diseases recommends referring patients with AKI if there are features suggestive of a diagnosis other than prerenal azotemia or acute tubular necrosis 3, 4

Exceptions to Referral

• The American Journal of Kidney Diseases suggests that patients with eGFR <30 mL/min/1.73 m² may not require referral if GFR is stable, diagnosis is relatively clear, or very advanced age or presence of comorbidity indicates a short life expectancy 1, 4

Multidisciplinary Care Approach

• The American Journal of Kidney Diseases recommends a multidisciplinary approach for patients with progressive CKD who are at high risk of ESRD with eGFRs <30 mL/min/1.73 m², those with rapid progression, or those with complex comorbidity 2, 5
• The multidisciplinary team should include or have access to dietary counseling, education about different renal replacement therapy options, transplant options, vascular access surgery, and ethical, psychological, and social care 3, 4

Common Pitfalls to Avoid

• The American Journal of Kidney Diseases recommends avoiding late referral (less than 1 year before start of renal replacement therapy) as it is associated with worse outcomes 3
• The American Journal of Kidney Diseases and Diabetes Care suggest recognizing non-diabetic kidney disease in patients with diabetes (absence of retinopathy, heavy proteinuria, active urine sediment) 8, 10
• The American Journal of Kidney Diseases and Diabetes Care recommend not discontinuing ACE inhibitors or ARBs for minor increases in serum creatinine (<30%) in the absence of volume depletion 7
• The American Journal of Kidney Diseases and Diabetes Care suggest adjusting medication dosages in patients with decreased kidney function 8

Nephrology Referral for Stage 3b CKD with Declining eGFR

Indications for Nephrology Referral

• The American Journal of Kidney Diseases recommends that patients with stage 3b CKD and evidence of progression, such as a decline in eGFR from 42 to 34 mL/min/1.73m², should be referred to nephrology for specialist evaluation and co-management 11, 12
• Rapid decline in kidney function (>5 mL/min/1.73m² reduction) is a specific indication for specialist evaluation, as stated by the American Journal of Kidney Diseases 13

Benefits of Early Referral

• Early referral to nephrology enables coordinated care to slow CKD progression, as recommended by the American Journal of Kidney Diseases and the Mayo Clinic Proceedings 11, 14
• The American Journal of Kidney Diseases suggests that early referral improves management of complications as disease worsens, and allows preparation for potential kidney replacement therapy if needed 14, 15
• The Mayo Clinic Proceedings states that early referral increases appropriate use of renin-angiotensin-aldosterone system blockers and optimizes management of comorbidities, such as anemia, hypertension, and CKD mineral and bone disorders 11, 14

Risk Assessment and Management Considerations

• The American Journal of Kidney Diseases indicates that stage 3b CKD (eGFR 34 mL/min/1.73m²) and declining kidney function (from 42 to 34 mL/min/1.73m²) are risk factors for disease progression 11, 13, 12
• The Mayo Clinic Proceedings recommends optimization of RAAS blockers and SGLT2 inhibitors for kidney protection, blood pressure management with a target of 130 mmHg systolic, and further improvement of glycemic control (current A1C 7.5%, target <7.0%) 11

Multidisciplinary Care Approach

• The American Journal of Kidney Diseases suggests that patients with stage 3b CKD and evidence of progression benefit from a multidisciplinary approach, including shared care between primary care and nephrology, and structured education programs 11, 13, 14, 15
• The Mayo Clinic Proceedings recommends incorporating dietary counseling for sodium and protein restriction, diabetes management optimization, and medication review and adjustment into the multidisciplinary care approach 11, 15

Special Considerations for Diabetic Kidney Disease

• The Mayo Clinic Proceedings states that patients with diabetes and declining kidney function benefit particularly from nephrology co-management, and that SGLT2 inhibitors may cause initial eGFR drop but provide long-term kidney protection 11

Laboratory Evaluation Prior to Nephrology Referral

Baseline Metabolic Panel

Core Kidney Function Assessment

Urinalysis and Microscopy

Anemia and Mineral‑Bone Disorder Evaluation

Metabolic Acidosis and Optional Enzyme Testing

Diabetes‑Specific Laboratory Considerations

Recommendations to Avoid Unnecessary Testing

Additional Diagnostic Steps for Suspected Malignancy

Laboratory Evaluation Prior to Nephrology Referral for CKD Stage IIIb

Mineral‑Bone Disorder Assessment

• Measure intact parathyroid hormone, serum calcium, phosphate, and 25‑hydroxyvitamin D at least once when estimated GFR falls below 45 mL/min/1.73 m², because parathyroid hormone elevation typically begins when GFR drops below 60 mL/min/1.73 m². 19

Anemia Screening

• Obtain a complete blood count to screen for anemia, which becomes markedly more prevalent in CKD stage IIIb. 19
• Check hemoglobin at least every 3 months in patients with estimated GFR ≤ 30 mL/min/1.73 m². 19
• When hemoglobin falls below 12 g/dL in women or 13 g/dL in men, order a comprehensive iron panel (serum iron, total iron‑binding capacity, ferritin, transferrin saturation). 19

Nutritional Status Assessment

• Measure serum albumin and monitor it every 3 months in CKD stage IIIb. 19
• Unintentional weight loss > 5 % of body weight, a decline in serum albumin > 0.3 g/dL, or an albumin level < 4.0 g/dL indicates malnutrition and warrants dietary counseling. 19

Cardiovascular Risk Assessment

• Obtain a fasting lipid panel (total cholesterol, LDL‑C, HDL‑C, triglycerides) because dyslipidemia is common in CKD and increases cardiovascular risk. 19