The kidneys filter waste products and excess fluid from the blood. When kidney function declines, waste builds up, leading to serious health issues. Deciding when to initiate dialysis, a treatment that takes over these functions, involves a thorough medical evaluation. This decision is complex, relying on more than just a single laboratory value.
What eGFR Measures
The estimated Glomerular Filtration Rate (eGFR) indicates how well the kidneys are functioning. It measures the rate at which blood is filtered by the glomeruli, tiny filtering units within the kidneys. A higher eGFR indicates healthier kidney function, while a lower number suggests reduced filtration capacity.
Healthcare providers calculate eGFR using a formula considering creatinine levels, age, and sex. Creatinine is a waste product healthy kidneys efficiently remove. A normal eGFR for adults is typically around 100 mL/min/1.73m², though it naturally decreases with age. An eGFR below 60 mL/min/1.73m² for three months or more, or an eGFR above 60 with signs of kidney damage like protein in the urine, indicates chronic kidney disease (CKD).
Stages of Chronic Kidney Disease
Chronic Kidney Disease (CKD) is categorized into five stages based on eGFR values. Stage 1 signifies kidney damage with an eGFR of 90 mL/min/1.73m² or greater, often without noticeable symptoms. Stage 2 involves a slight reduction in kidney function, with an eGFR between 60 and 89 mL/min/1.73m².
Stage 3, divided into 3a (eGFR 45-59 mL/min/1.73m²) and 3b (eGFR 30-44 mL/min/1.73m²), indicates a moderate reduction where symptoms may begin to appear. Stage 4 represents a severe loss of kidney function, with an eGFR ranging from 15 to 29 mL/min/1.73m².
The most advanced stage is Stage 5 CKD, defined by an eGFR below 15 mL/min/1.73m². This indicates kidney failure, meaning the kidneys have lost almost all ability to filter waste and fluid. While Stage 5 correlates with the need for dialysis or kidney transplant, this eGFR alone does not always mean immediate dialysis is required.
Factors Beyond the eGFR Number
While an eGFR below 15 mL/min/1.73m² marks severe kidney failure, dialysis initiation is not solely based on this number. Instead, the presence and severity of symptoms and clinical complications often dictate timing. These signs indicate the kidneys can no longer adequately maintain the body’s internal balance.
Uremia, the accumulation of waste products, is a significant factor. Symptoms include persistent nausea, vomiting, loss of appetite, fatigue, and difficulty concentrating. Dialysis alleviates these by removing toxins.
Fluid overload is another complication that may necessitate dialysis. When kidneys fail, they cannot remove excess fluid, leading to swelling and breathing issues. If medication cannot manage this, dialysis becomes necessary to remove excess fluid and prevent complications.
Dangerous electrolyte imbalances, such as high potassium or severe metabolic acidosis, can also trigger dialysis. These imbalances affect heart function and body chemistry. Uncontrolled high blood pressure, severe anemia unresponsive to treatment, and deteriorating nutritional status are additional clinical indicators. These symptoms and complications directly trigger dialysis, often taking precedence over a specific eGFR.
Making the Decision to Start Dialysis
The decision to begin dialysis is highly individualized, extending beyond eGFR values and symptoms. It involves a comprehensive evaluation by healthcare providers, considering the patient’s overall health, existing medical conditions, and quality of life. The goal is to initiate dialysis when it improves well-being and prevents complications, rather than at a fixed eGFR threshold.
Shared decision-making is a crucial component of this process, where patients and families actively participate in discussions with their medical team. This collaborative approach ensures the treatment plan aligns with the patient’s values, preferences, and lifestyle goals. Some patients may prefer managing symptoms to delay dialysis, while others might opt for earlier initiation to avoid complications. The decision ultimately balances medical necessity with individual circumstances and informed consent.