Answer: Although the first description of “reusing” hemodialyzers dates back to 1963,₁ any discussion relating to this topic remains controversial.  Inevitably, three questions are asked: Why are dialyzers reused? How are dialyzers reprocessed? What effect do reprocessed dialyzers have on treatment adequacy and outcome?

The prevalence of dialyzer reuse or reprocessing for use in the same patient varies throughout the world. Data from the Centers for Disease Control and Prevention (CDC) showed that in the United States in 1999 of the 3,483 centers surveyed, 80 percent practiced reprocessing, representing a small decline from 1997 when 82 percent were reusing. However, in Japan , law prohibits the reuse of dialyzers, while its use in many European countries varies. This variation may be attributed to two factors: reimbursement for the cost of dialysis and legislation related to product labeling.

The US reimbursement rate has been frozen since 1982 leading to the continued use of “large surface area, bio-compatible high efficiency/high flux dialyzers,” which are dependent on reuse. Paradoxically, in Canada , which has a higher reimbursement rate than the United States , there is nevertheless also increased use of reprocessing.₂ In European countries, the introduction of the Medical Devices Directive has led to the discontinuation of reuse of medical devices labeled for single use. For example, Portugal , which had 77 percent of its patients reusing before the directive, has prohibited the practice of reuse in compliance with this directive. In the UK , despite the directive, 10 percent of the renal units continue reprocessing, all using high flux dialyzers. Within the UK , the reimbursement rate is not on a per treatment basis but rather a global lump sum, budgeted for each dialysis unit that increases at a lower rate than the increase in dialysis population and operational costs. Although the UK is committed to applying the directive on reuse, this has not yet been fully implemented. The cost implications in stopping reuse have already generated intense debate on how to cover the cost shortfall in the clinics that are reusing but wish to continue to offer high flux treatment to their patients. It is likely that unless additional funding is made available, high flux high efficiency dialysis treatments will be discontinued.

The reasons for the differences in device labeling may be attributed to the fact that within the United States , dialyzer reuse was an established fact of life and complying with the U.S. Food and Drug Administration only recognized what had already been done for years. Such compliance however, is not merely a difference in labeling. Manufacturers of dialyzers also have to provide potential customers with documentation, quality control and studies detailing the procedures by which dialyzers can be reused.

In countries where labor costs are low, the cost of the dialyzer represents a much higher portion of the overall cost of hemodialysis treatment than in the United States and consequently the financial incentive to reuse is much greater. For example, in Poland 88 percent of patients are dialyzed on reused dialyzers, while in Bulgaria 100 percent of patients reuse dialyzers. Reuse also offers the availability of treatment to patients in countries where despite many pressing primary care medical needs, hemodialysis treatment would not be otherwise available, for example South Africa. In such countries, even with reuse, access to dialysis remains limited. Other countries such as Singapore , through the National Kidney Foundation of Singapore (NKFS), aim to “provide highly subsidized, quality treatment, essential drugs and patient care” - a strategy that is only possible with reuse.

With the introduction of highly automated production facilities for dialyzers, economies of scale can be achieved. This has meant that there has been a reduction in the cost of high efficiency/high flux dialyzers in the United States . This has resulted in the largest dialysis provider within the United States implementing a phased move towards single use of dialyzers.

The reasons for this are not hard to understand. First, as stated above, high efficiency/high flux dialysis is now affordable in a single use package. Second, using these dialyzers means that in most cases patients can still receive the same high quality treatment previously only available by reprocessing the more expensive dialyzers. Third, with the cost issue generally removed, why would dialysis providers subject themselves to the extensive policies, procedures and quality controls to operate a reuse program when there is no or little financial incentive to do so? Operating a reuse program requires constant attention to detail and ongoing quality control. This is a step that would be eliminated in the day-to-day operation of a clinic.

The move by some dialysis providers from reuse to single use in the United States does not necessarily mean reuse does not have a place in the treatment of end-stage renal disease. There are still many providers, where even with the lower cost of the new generation of dialyzers, such as the Fresenius F70 or the Optiflux 160, that will need to rely upon reuse for their economic viability. In addition, some patients will continue to require treatment with the more expensive large surface area dialyzers and if there is a significant number of these patients in a clinic, reuse may still need to be practiced for financial reasons. Furthermore, if the discontinuation of reuse limits the available devices for specific patients or patient groups, this would not be considered acceptable.₃ Lower dialyzer prices could resolve the issue of reuse but this does not seem likely to happen soon.

The reprocessing of dialyzers involves several discrete steps; a major element of this is the rinsing and cleaning of the device and its disinfection and storage prior to the next use. A number of different cleaning techniques are available, which include the use of formaldehyde (used by 33 percent of the dialysis centers reusing in 1999), peracetic acid (58 percent) glutaraldehyde (6 percent) and heat with or without citric acid (3 percent), the latter eliminating all the potential pitfalls associated with chemical reprocessing. The effect of reprocessing on the removal of small molecules such as urea during dialysis with a reprocessed dialyzer is relatively minor. Alterations in the removal of mid-sized molecules may, on the other hand, differ which in turn may influence long-term well-being. 

Retrospective analysis of patient outcomes when reusing, based on patients treated in the 1980s and published in the mid 1990s, have suggested an association between dialyzer reuse with peracetic acid mixtures and an increased risk of death with certain types of patients._4,5 These reports were subsequently challenged and indicated that factors other than reuse itself were responsible for the increased mortality. The method of reuse rather than the effect of the specific germicide may have been responsible. It should be stressed that many of the patients treated in these studies were using unmodified cellulose-based dialysis membranes, which have little relevance in contemporary dialysis practices.

In conclusion, reuse, provided the appropriate safety procedures and validated procedures are applied, such as those provided by the dialyzer and germicide manufacturer, RD47 2002 Reuse of Hemodialyzers from the Association for the Advancement of Medical Instrumentation (AAMI), the National Association of Nephrology Technicians (NANT) and the Centers for Disease Control and Prevention, Atlanta, Georgia (CDC) produce a substantial cost saving without compromising patient safety or effectiveness of the treatment delivered. In view of this, coupled with the unlikely increase in the cost of treatment reimbursement, the reprocessing of dialyzers will continue to form a part of therapy in a fraction of the dialysis population.

References:

1. Shaldon S, Silva H, Rosen SM: Technique of refrigerated coil preservation hemodialysis withfemoral Venous catheterization. Br Med J 1:1716-1717, 1963.

2. Blagg CR, Seminars in Dialysis - Vol 11, No 5 (September-October) 1998 pp 279-281.

3. Levin NW, Levin R, Folden T. Vol 11, No 5 (September-October) 1998 pp 281-282.

4. Held PJ, Wolfe RA, Gaylin DS, Port FK, Levin NW, Turenne MN. Analysis of the association of dialyzer reuse practices and patient outcomes. Am J Kidney Disease 23:692-708, 1994.

5. Feldman HI, Kinosian M, Bilker WB, Holmes JH, Paul MV, Escarce JJ: Effect of dialyzer reuse on survival of patients treated with hemodialysis. JAMA 276:620, 1996.

Answer provided by Robert Levin, MD and Nicholas Hoenich, PhD. Dr. Levin is the Technical Director at the Renal Research Institute. Dr. Hoenich is the past Visiting Research Laboratory Director at the Renal Research Institute. He is currently a lecturer at the School of Clinical Sciences, University of Newcastle, Newcastle-upon-Tyne, UK.

The Dear Doctor column provides readers with an opportunity to submit renal related health questions to healthcare professionals who specialize in the area of concern. The answers are not to be construed as a diagnosis and therefore, altercations in current healthcare should not occur until the patient's physician is consulted.

This article originally appeared in aakpRENALIFE, January 2003 Volume 18 Number 4. 

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