What are the current indications for initiating dialysis in patients with impaired renal function?

Current Indications for Dialysis Initiation

Dialysis should be initiated based on clinical symptoms and complications—not GFR alone—with conservative management continuing until GFR <15 mL/min/1.73 m² unless specific absolute indications are present. 1, 2

GFR Thresholds and Timing

Target GFR for initiation is approximately 10 mL/min/1.73 m² based on theoretical considerations, with conservative management recommended until GFR falls below 15 mL/min/1.73 m² unless specific clinical indications mandate earlier intervention. 1, 2 The mean GFR at dialysis initiation in 2003 was 9.8 mL/min/1.73 m², with lower values (7-9 mL/min/1.73 m²) for young and middle-aged adults and higher values (10-10.5 mL/min/1.73 m²) for children and elderly patients. 1, 2

Early dialysis initiation (GFR >10 mL/min/1.73 m²) in asymptomatic patients provides no survival benefit and may cause harm. 3, 2, 4, 5 When corrected for lead-time bias, there is no clear survival advantage to starting dialysis earlier at higher GFR levels. 1, 2

Critical Measurement Caveat

In patients with unusual creatinine generation or altered tubular secretion, obtain measured GFR using 24-hour urine collection for creatinine and urea clearance rather than relying on estimated GFR. 1, 3, 2 A weekly Kt/V of 2.0 approximates a kidney urea clearance of 7 mL/min and creatinine clearance of 9-14 mL/min/1.73 m². 1, 2

Absolute Indications for Dialysis (Override GFR Threshold)

Dialysis must be initiated when any of the following are present, regardless of GFR level:

Uremic Symptoms

• Pericarditis 3, 2
• Encephalopathy 3, 2
• Intractable nausea/vomiting 3, 2
• Bleeding diathesis 3, 2

Volume and Cardiovascular Complications

• Volume overload refractory to diuretic therapy 3, 2
• Uncontrolled hypertension despite maximal medical management 3, 2

Metabolic Derangements

• Severe metabolic acidosis unresponsive to medical therapy 3, 2
• Hyperkalemia unresponsive to medical therapy 3, 2

Nutritional Deterioration

Protein-energy malnutrition that develops or persists despite vigorous attempts to optimize protein and energy intake, with no apparent cause other than low nutrient intake. 1, 3, 2 This includes:

• Declining edema-free body weight 1, 2
• Falling serum albumin concentration 1, 2
• Lean body mass <63% 1, 2

Conditions Allowing Safe Deferral (Even with GFR <10 mL/min/1.73 m²)

Dialysis may be safely deferred even when GFR <10 mL/min/1.73 m² if ALL of the following are present:

• Stable or increased edema-free body weight 1, 2
• Adequate nutritional parameters: serum albumin above the lower limit for the laboratory and stable or rising, subjective global assessment score indicating adequate nutrition 1, 2
• Complete absence of clinical signs or symptoms attributable to uremia 1, 2

Critical Risks of Dialysis to Consider

Dialysis Is Not Innocuous

• Dialysis does not replace all kidney functions and imposes significant burden on patients, families, and the healthcare system. 1, 2
• Hemodialysis-related hypotension may accelerate loss of residual kidney function, which is particularly problematic in patients who may recover renal function. 1, 3, 2
• Vascular access complications are common, with hemodialysis catheter-related bloodstream infections occurring at 1.1-5.5 episodes per 1000 catheter-days, affecting approximately 50% of patients within 6 months. 5
• Peritonitis occurs at 0.26 episodes per patient-year, affecting about 30% of individuals in the first year of peritoneal dialysis. 5

Observational Data Reveals Selection Bias

Patients with more comorbidities tend to start dialysis at higher GFR levels, but these frailer patients do not live as long as healthier patients who start later—this reflects patient selection bias rather than benefit from early initiation. 1, 2, 6

Initial Dialysis Prescription Protocol

When dialysis is indicated, use a "low and slow" approach to minimize dialysis disequilibrium syndrome and hemodynamic instability:

• Initial session duration: 2-2.5 hours (not full 4 hours) 3, 2
• Reduced blood flow rates: 200-250 mL/min 3, 2
• Minimal ultrafiltration during first session, focusing on clearance rather than fluid removal 3, 2
• Frequent vital sign monitoring every 15-30 minutes during the first session, with close observation for neurological symptoms 3
• Gradual dose escalation over subsequent sessions as tolerated 3, 2

Common Pitfalls to Avoid

Do not initiate dialysis based on GFR or creatinine alone without clinical symptoms or complications. 3, 2, 4, 5 The decision represents a compromise designed to maximize quality of life by extending the dialysis-free period while avoiding complications that reduce length and quality of dialysis-assisted life. 1, 2

Avoid aggressive first dialysis sessions, as rapid removal of uremic toxins can cause cerebral edema, seizures, and cardiovascular instability. 3

In patients with reversible causes of kidney injury (such as bilateral obstructive uropathy), address the underlying cause first before initiating dialysis, unless life-threatening complications are present. 7