Criteria for Dialysis Initiation
Dialysis should be initiated based on clinical symptoms and signs of uremia rather than a specific GFR threshold, typically when GFR falls between 5-10 mL/min/1.73 m² in the presence of uremic complications, as early initiation at higher GFR levels (>10 mL/min/1.73 m²) provides no survival benefit and may cause harm. 1, 2, 3
GFR Thresholds
- Do not initiate dialysis based solely on GFR or creatinine values 1, 4
- Plan for dialysis access when GFR <15-20 mL/min/1.73 m² or when risk of kidney replacement therapy exceeds 40% over 2 years 1
- Target GFR for actual initiation is approximately 5-10 mL/min/1.73 m², with most patients starting around 5.8 mL/min/1.73 m² 2, 5, 3
- Dialysis may be safely deferred until GFR is 5-7 mL/min/1.73 m² in asymptomatic patients with careful monitoring 4
- A weekly Kt/V <2.0 (approximating kidney urea clearance of 7 mL/min and creatinine clearance of 9-14 mL/min/1.73 m²) suggests need for dialysis consideration 1
Absolute Indications for Dialysis (Regardless of GFR)
Initiate dialysis immediately when any of the following are present:
Uremic Symptoms
- Pericarditis (uremic) 1, 2
- Encephalopathy or altered mental status attributable to uremia 1, 2
- Intractable nausea and vomiting despite medical management 1, 2
- Bleeding diathesis from uremic platelet dysfunction 2
- Intractable pruritus refractory to medical therapy 1
- Serositis 1
Metabolic Derangements
- Severe hyperkalemia unresponsive to medical therapy 1, 2
- Severe metabolic acidosis refractory to bicarbonate supplementation 1, 2
- Other medically resistant electrolyte abnormalities 1
Volume and Cardiovascular Issues
- Volume overload refractory to diuretic therapy 1, 2
- Pulmonary edema 2
- Uncontrolled hypertension despite maximal medical management 1, 2
Nutritional Deterioration
- Progressive deterioration in nutritional status refractory to dietary intervention 1, 2
- Protein-energy malnutrition that persists despite vigorous attempts to optimize intake 1, 2
- Declining edema-free body weight 1, 2
- Falling serum albumin levels 2
- Lean body mass <63% 2
Pediatric-Specific Indications
- Poor growth refractory to optimized nutrition, growth hormone, and medical management 1
- Malnutrition or growth failure despite medical and dietary management 1
Conditions Allowing Safe Deferral of Dialysis (Even with GFR <10 mL/min/1.73 m²)
Dialysis may be deferred if ALL of the following criteria are met:
- Stable or increased edema-free body weight 1, 2
- Adequate nutritional parameters (serum albumin above lower limit of normal and stable or rising) 1, 2
- Subjective global assessment score indicating adequate nutrition 1
- Complete absence of clinical signs or symptoms attributable to uremia 1, 2
Critical Pitfalls and Caveats
Lead-Time Bias
- Observational data showing better outcomes with early dialysis initiation are confounded by lead-time bias 2, 6
- When corrected for lead-time bias, early initiation at GFR >10 mL/min/1.73 m² shows no survival advantage and potential harm 2, 6
- Patients with more comorbidities tend to start dialysis at higher GFR levels but have worse outcomes due to underlying disease burden, not timing of initiation 2
GFR Estimation Limitations
- Creatinine-based eGFR formulas are inaccurate in advanced CKD 4, 7
- In patients with unusual creatinine generation (extremes of muscle mass, dietary protein intake) or altered tubular secretion, use measured GFR via 24-hour urine collection for creatinine and urea clearance 2, 6
- BUN/creatinine ratio >15 mg/mg predicts need for earlier dialysis initiation 5
Patient-Specific Risk Factors for Earlier Initiation
The following predialysis characteristics predict need for dialysis at higher GFR:
- Heart failure (adjusted OR 3.68) 5
- Serum albumin <4.0 g/dL (adjusted OR 2.22) 5
- BUN/creatinine ratio >15 mg/mg (adjusted OR 1.92) 5
- Hyperuricemia (adjusted OR 1.84) 5
Risks of Dialysis Itself
- Dialysis does not replace all kidney functions and carries significant risks 2
- Hemodialysis-related hypotension may accelerate loss of residual kidney function 2
- Catheter-related bloodstream infections occur at 1.1-5.5 episodes per 1000 catheter-days, affecting ~50% of patients within 6 months 3
- Peritonitis occurs at 0.26 episodes per patient-year, affecting ~30% in first year of peritoneal dialysis 3
- Vascular access complications are common 2
Initial Dialysis Prescription
When dialysis is initiated, use a "low and slow" approach for the first session:
- Initial session duration: 2-2.5 hours (not full 4 hours) 2
- Reduced blood flow rates: 200-250 mL/min 2
- Minimal ultrafiltration during first session, focusing on clearance rather than fluid removal 2
- Gradual dose escalation over subsequent sessions as tolerated 2
Special Populations
Pediatric Patients
- Follow adult guidelines with GFR <15 mL/min/1.73 m² as threshold 1
- Pursue preemptive kidney transplantation as treatment of choice, typically at GFR 5-15 mL/min/1.73 m² depending on age, size, and progression rate 1
- Consider higher dialysis doses and protein intakes at 150% for younger children 1
Elderly and Frail Patients
- Dialysis initiation may be associated with worse outcomes and quality of life due to comorbidities and frailty 4
- Consider comprehensive conservative management as alternative to dialysis 1, 4
- Decision should involve shared decision-making with patient and family members 4, 3
Clinical Decision Framework
Use this algorithmic approach:
At GFR 15-20 mL/min/1.73 m²: Begin dialysis access planning and preemptive transplant evaluation 1
At GFR 10-15 mL/min/1.73 m²: Intensify monitoring for uremic symptoms, nutritional status, and metabolic derangements 1
At GFR 5-10 mL/min/1.73 m²: Initiate dialysis if ANY absolute indication present; otherwise continue conservative management with close follow-up 1, 2, 3
At GFR <5 mL/min/1.73 m²: Strongly consider dialysis initiation even in asymptomatic patients, as risk of sudden uremic complications increases 4
Reassess need every 1-2 weeks when GFR <10 mL/min/1.73 m², monitoring for development of any absolute indication 2