From the Guidelines
Patients with an estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73m² should be referred to nephrology for specialized care, as recommended by the most recent guidelines 1. Additionally, referral is recommended for those with eGFR 30-60 mL/min/1.73m² who have rapid decline (>5 mL/min/year), persistent proteinuria (urine protein-to-creatinine ratio >0.5), uncontrolled hypertension, or recurrent acute kidney injury. Early referral is crucial as it allows for timely intervention to slow progression of chronic kidney disease, manage complications like anemia and mineral bone disorders, prepare for renal replacement therapy if needed, and potentially identify reversible causes of kidney dysfunction. While primary care providers can manage early-stage kidney disease with blood pressure control (targeting <130/80 mmHg), use of ACE inhibitors or ARBs, diabetes management, and lifestyle modifications, nephrology consultation provides specialized expertise for more advanced or complex cases. Regular monitoring of kidney function, electrolytes, and proteinuria should continue regardless of referral status, as suggested by recent studies 1. The definition of moderate-to-severe CKD requires an eGFR of <60 mL/min/1.73 m2 or albuminuria of ≥30 mg/g (≥3 mg/mmol), according to the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. It is essential to prioritize the single most recent and highest quality study, which in this case is the 2023 standards of care in diabetes 1, to ensure the best possible outcomes in terms of morbidity, mortality, and quality of life. Some key points to consider when referring patients to nephrology include:
- eGFR below 30 mL/min/1.73m²
- Rapid decline in eGFR (>5 mL/min/year)
- Persistent proteinuria (urine protein-to-creatinine ratio >0.5)
- Uncontrolled hypertension
- Recurrent acute kidney injury
- The need for specialized expertise in managing complications and preparing for renal replacement therapy. By following these guidelines and considering the most recent evidence, healthcare providers can ensure that patients with chronic kidney disease receive the best possible care and outcomes.
From the Research
EGFR in Nephrology
- EGFR, or estimated glomerular filtration rate, is a crucial measure in nephrology for assessing kidney function and diagnosing chronic kidney disease (CKD) 2, 3.
- The glomerular filtration rate (GFR) is a key indicator of kidney health, and nephrologists often focus on this aspect of kidney function to grade the severity of CKD 2.
- However, the utility of measured GFR (mGFR) has been questioned, and its measurement is particularly important in situations where estimated GFR is known to provide imprecise estimates of glomerular function, such as in cases of sarcopenia and advanced cirrhosis 2.
- The use of erythropoiesis-stimulating agents (ESAs) like epoetin alfa is common in treating anemia in patients with CKD, and studies have shown that these agents can be effective in improving hemoglobin levels and quality of life 4, 5, 6.
- The dosing schedule of ESAs can vary, and extended dosing schedules of up to once every four weeks have been shown to be effective in maintaining hemoglobin levels in patients with anemia of CKD 6.
Clinical Applications
- Measured GFR can be useful in individualizing therapy among patients with CKD, particularly in situations where estimated GFR is imprecise 2.
- ESAs like epoetin alfa can be used to treat anemia in patients with CKD, and their use has been associated with improvements in hemoglobin levels and quality of life 4, 5, 6.
- The choice of ESA and dosing schedule should be based on individual patient needs and characteristics, and clinicians should be aware of the potential risks and benefits of these agents 5.
Limitations and Future Directions
- The use of estimated GFR has limitations, and measured GFR may be necessary in certain situations to accurately assess kidney function 2, 3.
- Further research is needed to fully understand the benefits and risks of ESAs in patients with CKD, particularly in terms of their effects on cardiovascular outcomes and mortality 5.