Why should the first dialysis treatment be initiated at a low dose and progressed slowly?

Why First Dialysis Treatment Should Be Low and Slow

The first dialysis treatment should be initiated at a low dose and progressed slowly to minimize the risk of dialysis disequilibrium syndrome, hemodynamic instability, and other complications that can increase morbidity and mortality in patients new to dialysis. 1

Physiological Rationale for Low and Slow Approach

• When patients begin dialysis, their bodies have adapted to high levels of uremic toxins, and rapid removal can cause significant physiological disturbances 1
• Starting with a lower dialysis dose allows for gradual adaptation of the body to the removal of uremic toxins, preventing rapid shifts in electrolytes, osmolality, and fluid status 1
• The body needs time to adjust to these changes, particularly in patients who have been uremic for an extended period 1

Specific Risks of Aggressive Initial Dialysis

Dialysis Disequilibrium Syndrome

• Rapid removal of urea creates an osmotic gradient between the brain and blood, leading to cerebral edema 1
• Symptoms include headache, nausea, vomiting, restlessness, seizures, and in severe cases, coma 1
• Risk is highest in patients with very high BUN levels at dialysis initiation 1

Hemodynamic Instability

• Rapid fluid removal can cause hypotension, especially in patients with cardiovascular comorbidities 1
• Elderly patients and those with significant comorbidities are at particularly high risk for hemodynamic complications 1
• Hypotension during dialysis can lead to myocardial stunning, arrhythmias, and increased cardiovascular mortality 1

Electrolyte Imbalances

• Rapid correction of electrolyte abnormalities (particularly potassium, calcium, and phosphorus) can lead to cardiac arrhythmias 1
• Patients with aluminum overload are at risk for acute aluminum neurotoxicity if dialysis is too aggressive initially 1

Recommended Approach for First Dialysis Treatment

• Initial session should be shorter (2-2.5 hours) with reduced blood flow rates (200-250 mL/min) and lower dialysate flow rates 1
• Ultrafiltration should be minimal during the first session, focusing primarily on clearance rather than fluid removal 1
• Dialysis dose should be gradually increased over subsequent sessions as the patient tolerates the treatment 1
• Blood flow rates, treatment time, and ultrafiltration goals should be progressively increased over 1-2 weeks 1

Special Considerations for High-Risk Patients

• Patients with very high BUN levels (>100 mg/dL) require especially cautious initiation 1
• Elderly patients and those with significant cardiovascular disease need more gradual initiation protocols 1
• Patients with residual kidney function benefit from an incremental approach to dialysis initiation, which may help preserve remaining function longer 2
• Patients with aluminum overload require specific protocols with high-flux membranes and careful monitoring 1

Common Pitfalls in Initial Dialysis Prescription

• Focusing solely on estimated GFR rather than patient symptoms when determining dialysis initiation timing 3
• Setting overly aggressive ultrafiltration goals for the first treatment 1
• Failing to monitor for signs of dialysis disequilibrium during the first treatment 1
• Not accounting for access recirculation or inadequate blood flow, which can reduce effective clearance 1
• Premature discontinuation of the first dialysis session due to complications that could have been prevented with a more conservative approach 1

Monitoring During Initial Dialysis

• Frequent vital sign checks (every 15-30 minutes) 1
• Close observation for neurological symptoms (headache, nausea, confusion) 1
• Careful assessment of access function and blood flow 1
• Post-dialysis evaluation for delayed complications 1

By following a low and slow approach to initial dialysis, clinicians can minimize complications and improve patient outcomes during this critical transition to renal replacement therapy 1.