From the Guidelines
Primary care providers should refer patients to nephrology when their glomerular filtration rate (GFR) falls below 30 mL/min/1.73m² (CKD stage 4), as recommended by the most recent guidelines 1. However, earlier referral at GFR levels of 30-60 mL/min/1.73m² (CKD stage 3) is appropriate when there are complicating factors such as:
- Rapidly declining kidney function (decrease of >5 mL/min/1.73m² per year)
- Persistent significant proteinuria (>500 mg/day)
- Difficult-to-manage hypertension requiring multiple medications
- Recurrent nephrolithiasis
- Hereditary kidney disease
- Uncertain etiology of kidney disease Referral should also be considered regardless of GFR level when there is:
- Suspected glomerulonephritis
- Hematuria with proteinuria
- Electrolyte abnormalities that are difficult to manage Early nephrology consultation allows for specialized management to potentially slow CKD progression, optimize medication dosing, prepare for renal replacement therapy if needed, and address complications like anemia, metabolic bone disease, and cardiovascular risk factors, as supported by recent studies 1. The nephrologist can also help with patient education about kidney disease management and treatment options. Some key points to consider when referring patients to nephrology include:
- The threshold for referral may vary depending on the frequency with which a provider encounters patients with diabetes and kidney disease
- Consultation with a nephrologist when stage 4 CKD develops (eGFR <30 mL/min/1.73 m2) has been found to reduce cost, improve quality of care, and delay dialysis 1
- Other specialists and health care professionals should also educate people with diabetes about the progressive nature of CKD, the kidney preservation benefits of proactive treatment of blood pressure and blood glucose, and the potential need for renal replacement therapy 1
From the Research
Referral Criteria
The decision to refer patients to nephrology is based on several factors, including the glomerular filtration rate (GFR) level. According to the studies, the following are some key points to consider:
- Patients with a GFR <30 mL/min/1.73 m2 should be referred to a nephrologist 2, 3, 4
- Patients with a rapid decline in GFR should also be referred to a nephrologist 2, 3
- The Kidney Failure Risk Equation (KFRE) can be used to guide referrals and reduce the burden of kidney failure 5
Factors Influencing Referral
Several factors can influence the decision to refer patients to nephrology, including:
- Age: younger patients may require earlier referral 6, 5
- Comorbidities: patients with complex medical histories may require earlier referral 6
- Ancestry: African American patients may require earlier referral 6
- Academic physician: patients seen by academic physicians may be more likely to be referred 6
Importance of Early Referral
Early referral to a nephrologist is crucial to prevent adverse outcomes, including: