Dialyzer Reuse in Hemodialysis: Safety, Risks, and Prevention
Dialyzer reuse is generally considered safe when performed according to established protocols, but facilities must strictly adhere to recommended reprocessing guidelines to minimize risks of infection, pyrogenic reactions, and reduced dialysis efficiency.
Safety and Efficacy of Dialyzer Reuse
Reprocessing dialyzers for reuse in the same patient has been a common practice in the United States, with 78% of hemodialysis clinics reprocessing dialyzers as of 2002, though this practice has declined in recent years 1.
Multiple large retrospective analyses have shown no significant differences in mortality or hospitalization risk between patients treated with single-use dialyzers versus those treated with properly reprocessed dialyzers 1, 2.
A large study examining 49,273 incident Medicare patients from 1998-1999 found no significant differences in mortality or first hospitalization risk among patients treated with single-use dialyzers compared to those treated with dialyzers cleansed using different reprocessing techniques 1.
Risks Associated with Dialyzer Reuse
Reduced Dialyzer Performance
Hemodialyzer performance, measured as blood-side urea clearance, may decline as a result of dialyzer reuse 1.
Studies have shown that urea clearance can decrease as the number of reuses increases, with some reports showing up to 20% decrease in urea clearance by 10 reuses even when following conventional reprocessing practices 1.
The HEMO Study showed that average loss of urea clearance was only 1-2% per 10 reuses for both low-flux and high-flux membranes reprocessed with different germicidal regimens 1.
Infection and Pyrogenic Reactions
Risks include potential for infection, pyrogenic reactions, toxicity from disinfectants, reduced dialyzer performance, and impaired removal of large molecules 1.
Hemodialysis patients are at increased risk for healthcare-associated infections due to their compromised immune systems and management of bloodstream through catheters 3.
Waterborne pathogens, including nontuberculous mycobacteria and gram-negative bacilli, can cause infections in dialysis patients if proper water management protocols are not followed 3.
Bacterial Contamination
Dialysis devices can become contaminated with bacteria, particularly Staphylococcus species, which are a common cause of hemodialysis catheter-related bloodstream infections 4.
Areas frequently touched by healthcare workers, such as touch screens, show higher contamination rates, with 48.2% of Staphylococcus species demonstrating high resistance to methicillin 4.
Prevention Strategies
Adherence to Reprocessing Guidelines
Dialysis facilities choosing to reuse dialyzers should follow the Association for the Advancement of Medical Instrumentation (AAMI) recommendations for reprocessing 1.
Dialyzers intended for reuse should have a blood compartment volume not less than 80% of the original measured volume or a urea (or ionic) clearance not less than 90% of the original measured clearance 1.
Monitoring relevant patient data, specifically examination of Kt/V and/or URR over time, is essential to ensure that all parameters relating to dialyzer clearance are being met 1.
Water Quality Management
Dialysis clinics should adhere to recommendations regarding monitoring and maintaining acceptable levels of bacteria and endotoxin in hemodialysis water and dialysate 3.
Regular sterilization of dilution water lines with low concentration sodium hypochlorite (30-100 ppm) can significantly reduce endotoxin levels 5.
Using sterile filtration with hollow fiber modules of polyamid can help achieve bacteria-free and endotoxin-free dialysate, which has been shown to reduce side effects such as blood pressure drops, headaches, muscular cramps, and nausea 6.
Monitoring Dialyzer Function
Total Cell Volume (TCV) measurements, ionic clearance, or urea clearances can all be used to assess the function of either fresh or reused dialyzers 1.
A 10% decrease in urea clearance could lead to inadequate dialysis if the dialysis prescription was marginal to begin with, so the patient's dialysis prescription should take into account the potential 10% loss in clearance (20% loss in TCV) that may occur with dialyzer reuse 1.
Direct measurements of ionic clearance (conductivity or sodium clearance) or urea clearances correlate closely with TCV results and can be used as alternatives to assess dialyzer function 1.
Special Considerations
The choice of germicide for reprocessing affects dialyzer performance. For example, high-flux polysulfone dialyzers reprocessed with bleach showed markedly increased β2-microglobulin clearances, whereas reprocessing the same dialyzer with peracetic acid appeared to have the opposite effect 1.
The use of poorly biocompatible, unmodified cellulose dialyzer membranes for hemodialysis is discouraged due to their association with adverse effects including activation of the complement pathway 1.
Rinsing associated with the reprocessing procedure may help remove undesirable dialyzer residuals such as ethylene oxide, bore fluids, potting compound fragments, and other noxious substances remaining after dialyzer manufacture 1.