Is there harm in dialyzing a patient multiple times?

Is There Harm in Dialyzing a Patient Multiple Times?

More frequent hemodialysis (>3 sessions per week) carries specific documented risks that must be weighed against potential benefits, including increased vascular access complications, accelerated loss of residual kidney function, potential for infection, and increased patient/caregiver burden.

Documented Harms of Frequent Dialysis

Vascular Access Complications

• Patients considering frequent hemodialysis must be informed about the increased risk of vascular access procedures and complications 1
• The Frequent Hemodialysis Network trials demonstrated that both short daily and nocturnal schedules increased the incidence of access complications, though access loss rates were not statistically higher 2
• The risk increases with each additional cannulation event, as there is a fixed probability of bacterial contamination per needle insertion 2

Loss of Residual Kidney Function

• Frequent hemodialysis can accelerate the decline in residual kidney function, particularly in patients who have recently started dialysis and still have substantial urine output 1, 2
• This is a critical consideration because residual kidney function provides continuous clearance between dialysis sessions and contributes significantly to overall adequacy 1
• The KDOQI guidelines specifically warn about this risk when recommending home long frequent hemodialysis 1

Infection Risk

• Observational studies indicate that infection-related hospitalization remains an ongoing challenge with short daily hemodialysis 2
• Poor infection control practices in the home setting, where intensive hemodialysis is typically delivered, may catalyze excess infection risk 2
• Greater treatment frequency necessarily increases the risk for infectious complications due to more frequent vascular access 2
• Buttonhole cannulation technique may further increase the risk for metastatic infections 2

Intradialytic Hypotension

• Patients must be informed about the potential for hypotension during more frequent dialysis sessions 1
• However, this risk is nuanced: frequent hemodialysis may actually reduce the per-session probability of intradialytic hypotension by 20-68% compared to conventional schedules due to lower ultrafiltration volumes per session 3

Patient and Caregiver Burden

• Increased caregiver burden is a documented risk of home long frequent hemodialysis 1
• The psychological impact of more frequent treatments can compromise quality of life and potentially lead to technique failure 2
• Patients may experience depression related to the increased time commitment required for dialysis 1

Mortality Considerations

The mortality data are equivocal and require careful interpretation:

• Extended follow-up of the Frequent Hemodialysis Network trials showed that short daily hemodialysis was associated with lower mortality risk compared to usual schedules 2
• However, nocturnal hemodialysis was associated with higher mortality risk in the same trials 2
• Observational studies suggest short daily hemodialysis may have lower mortality than both in-center hemodialysis and peritoneal dialysis, but these studies are subject to unmeasured confounding 2

Metabolic Disturbances

• Intensive hemodialysis can deplete solutes such as phosphorus to the extent that supplementation becomes necessary 2
• This represents a shift from the typical dialysis patient who requires phosphate restriction, creating a new management challenge 2

Clinical Decision-Making Algorithm

When considering more frequent dialysis:

1. Assess the indication: Consider additional sessions or longer treatment times for patients with large interdialytic weight gains, high ultrafiltration rates, poorly controlled blood pressure, difficulty achieving dry weight, or poor metabolic control (hyperphosphatemia, metabolic acidosis, hyperkalemia) 1

2. Evaluate residual kidney function: Exercise particular caution in patients with residual kidney function >2 mL/min, as frequent dialysis may accelerate its loss 1, 2

3. Assess vascular access: Ensure the patient has robust vascular access that can tolerate more frequent cannulation 1

4. Consider infection control: Verify that proper infection control practices can be maintained, particularly in home settings 2

5. Evaluate support systems: Assess whether adequate caregiver support exists to sustain the increased treatment burden 1

Common Pitfalls to Avoid

• Do not assume that more dialysis is always better—the relationship between dialysis dose and outcomes reaches a plateau of effectiveness 1
• Do not implement frequent dialysis without careful monitoring for access complications, infections, and residual kidney function decline 1, 2
• Do not overlook the psychological and social burden on patients and caregivers when prescribing intensive regimens 2
• Do not reduce dialysis dose based solely on residual kidney function without considering other vital benefits of dialysis 1