At what percentage of kidney function does a patient require dialysis due to Impaired Renal Function?

From the Guidelines

Dialysis is typically initiated when kidney function, measured by glomerular filtration rate (GFR), falls below 5-10 mL/min per 1.73m², considering a composite assessment of symptoms, signs, quality of life, preferences, and laboratory abnormalities. The decision to start dialysis is not based solely on the percentage of kidney function, but also takes into account the presence of uremic symptoms, fluid overload, electrolyte imbalances, and overall quality of life 1. According to the KDIGO 2024 clinical practice guideline, dialysis should be initiated if there are symptoms or signs attributable to kidney failure, inability to control volume status or blood pressure, progressive deterioration in nutritional status, or cognitive impairment 1.

Key Considerations

• The GFR range for initiating dialysis is often between 5 and 10 mL/min per 1.73m², but this can vary depending on individual patient factors 1.
• Planning for preemptive kidney transplantation and/or dialysis access should be considered in adults when the GFR is <15–20 mL/min per 1.73m² or risk of kidney replacement therapy is >40% over 2 years 1.
• The timing of dialysis initiation is individualized, taking into account the patient's symptoms, quality of life, and overall health status 1.

Clinical Implications

• Patients with significant symptoms or complications of kidney failure may require earlier initiation of dialysis, while those with stable conditions may be able to delay dialysis until kidney function declines further 1.
• The decision to start dialysis should be based on a comprehensive assessment of the patient's condition, rather than solely on the percentage of kidney function 1.

From the Research

Dialysis Initiation due to Impaired Renal Function

• The decision to initiate dialysis is based on the level of kidney failure and clinical evidence of uremia 2.
• Several nephrology societies advocate for the early start of dialysis when the glomerular filtration rate (GFR) is higher than or equal to 10 mL/min/1.73 m2 2.
• However, recent studies have reported no benefit in patient survival from initiating dialysis treatment at a higher GFR 2, 3.
• The available data indicate that the mortality while on dialysis may be higher with an early start, and that there is no significant benefit in terms of quality of life 2.
• In clinical practice, there is considerable variation in the timing of initiation of maintenance dialysis for patients with end-stage renal disease 2.
• Some studies suggest that dialysis can be initiated at a lower GFR (<7.0 mL/min) with careful clinical management, and at an even lower rate in selected elderly patients with a supplemented very low protein diet 2.
• The eGFR at which dialysis, compared with medical management, is associated with lower mortality varies by age 4.
• For patients aged <65-74,75-84, and ≥85 years, dialysis is associated with lower mortality for those with eGFR not exceeding 6-<9, <6,9-<12, and 9-<12 mL/min per 1.73 m2, respectively 4.
• There is no recommended estimated glomerular filtration rate (eGFR) threshold for initiating dialysis, and patient-clinician shared decision-making should help determine when to initiate dialysis 3.

Factors Influencing Dialysis Initiation

• Persistent signs and symptoms of uremia (e.g., nausea, fatigue) and volume overload (e.g., dyspnea, peripheral edema) inform the timing of therapy initiation 3.
• Worsening eGFR, metabolic acidosis, and hyperkalemia also inform the timing of therapy initiation 3.
• Cardiovascular and infection-related complications of maintenance dialysis are common 3.
• Chronic kidney failure-related systemic complications, such as anemia, hyperphosphatemia, hypocalcemia, and hypertension, often require pharmacologic treatment 3.

Age and Dialysis Initiation

• Older adults with advanced CKD typically lose renal function slowly and may die from associated comorbidities before they require dialysis 5.
• Observational data suggests that dialysis does not provide a survival benefit for older adults with poor mobility and high levels of comorbidity 5.
• The potential advantages and disadvantages of dialysis therapy should be considered in conjunction with each patient's unique goals and priorities 5.