What does an estimated Glomerular Filtration Rate (eGFR) of 6 indicate in the context of Chronic Kidney Disease (CKD)?

From the Guidelines

An eGFR of 6 indicates end-stage kidney disease (stage 5 chronic kidney disease), which is extremely severe kidney failure, requiring immediate medical intervention to prevent life-threatening complications. This means your kidneys are functioning at less than 15% of normal capacity, with 6 ml/min/1.73m² representing only about 5-6% of normal kidney function 1. At this level, waste products and fluid cannot be adequately removed from your body, and treatment options include dialysis (either hemodialysis or peritoneal dialysis) or kidney transplantation 1. Without these interventions, dangerous complications can develop including high potassium levels, fluid overload, and uremic symptoms (nausea, confusion, itching) 1.

Key Considerations

• You should be under the care of a nephrologist who will manage medications to control blood pressure, anemia, bone disease, and other complications 1.
• Dietary restrictions are also crucial, typically limiting potassium, phosphorus, sodium, and fluid intake 1.
• The U.S. Food and Drug Administration (FDA) revised its guidance for the use of metformin in CKD in 2016, recommending use of eGFR instead of serum creatinine to guide treatment and expanding the pool of patients with kidney disease for whom metformin treatment should be considered 1.
• SGLT2 inhibitors and GLP-1 RAs should be considered for patients with type 2 diabetes and CKD who require another drug added to metformin to attain target A1C or cannot use or tolerate metformin 1.

Treatment Options

• Dialysis (either hemodialysis or peritoneal dialysis) 1
• Kidney transplantation 1
• Medications to control blood pressure, anemia, bone disease, and other complications 1
• Dietary restrictions to limit potassium, phosphorus, sodium, and fluid intake 1

From the Research

Definition of eGFR and CKD

• eGFR, or estimated Glomerular Filtration Rate, is a test used to measure kidney function and detect chronic kidney disease (CKD) 2.
• CKD is defined as a persistent abnormality in kidney structure or function, such as a GFR <60 mL/min/1.73 m2 or albuminuria ≥30 mg per 24 hours, for more than 3 months 3.

Staging of CKD

• CKD is classified into five stages based on the GFR, with stage 1 being the least severe and stage 5 being the most severe 2.
• The eGFR value of 6 likely refers to a CKD stage, but without more context, it is difficult to determine the exact stage.
• However, an eGFR value of 6 is likely indicative of severe kidney dysfunction, possibly corresponding to CKD stage 5 4.

Limitations of eGFR

• eGFR has several limitations, including variability due to dietary intake, fluid and cardiovascular status, and blood pressure 5.
• eGFR may not accurately reflect kidney function in certain conditions or disease states, and its use as a diagnostic tool should be approached with caution 5.

Clinical Implications

• Patients with CKD, particularly those with severely decreased GFR, are at high risk for adverse outcomes, including cardiovascular disease, end-stage kidney disease, and death 3, 4.
• Accurate assessment of kidney function using eGFR equations is crucial for timely intervention and management of CKD 6.
• The choice of eGFR equation can impact the accuracy of kidney function assessment, and ethnicity-specific equations may be necessary to enhance accuracy and clinical utility in diverse populations 6.