Plate, Coil, and Hollow-Fiber Cuprammonium Cellulose Dialyzers: Discrepancy Between Incidence of Anaphylactic Reactions and Degree of Complement Activation

During the past 10 years, the incidence of severe anaphylactic reactions during dialysis [type A first-use syndrome (FUS)] at our center has been much lower when using cuprammonium cellulose plate (CC-P) dialyzers (0/37, 750 dialyses) or coil (CC-C) dialyzers (0/32, 500) than when using cuprammonium cellulose hollow-fiber (CC-F) dialyzers (8/21,022 dialyses, p less than 0.005 by Chi-square). To determine if the difference in type A FUS incidence between the three dialyzer types could be explained by differences in complement activation, we compared plasma concentrations of C3a des-arginine (des arg) in patients undergoing dialysis with these three varieties of dialyzers. Plasma C3a des arg values increased markedly in the dialyzer outflow blood with the three dialyzer configurations. The levels were similar with the dialyzer types when results were corrected for membrane surface area. Also, the degree of leukopenia was not markedly different with the three dialyzer types. Our findings suggest that complement activation per unit surface area is similar during dialysis with plate, coil, and hollow-fiber cuprammonium cellulose dialyzers. The lack of correlation between the degree of complement activation and the incidence of type A FUS suggests that membrane-induced complement activation is not of primary importance to type A dialyzer hypersensitivity reactions.     

Dialyzer Reuse Following Manual Reprocessing with a New Sterilant, RenNew-D

Dialysis patients are at risk for toxicity from formaldehyde used in the reprocessing of dialyzers for reuse; therefore, replacing formaldehyde as a dialyzer sterilant would be advantageous. The potential for RenNew-D as a sterilizing agent was investigated in seven stable in-center hemodialysis patients over 20 consecutive dialyses with cuprammonium cellulose hollow-fiber dialyzers. Treatment with RenNew-D showed no toxicity to patients or dialyzers except for two blood leaks occurring in one patient. The mean number of dialyzer uses was 4.9. In all the dialyzers that passed functional testing small solute clearances were maintained with reuse. The ability of RenNew-D to improve the biocompatibility of reused dialyzers was documented with mean neutrophil counts falling to only 78% of initial values during first reuse of dialyzers processed with RenNew-D compared with a decrease in neutrophil count to 2% of initial values during first use of the same dialyzers. Our results suggest that RenNew-D may be a useful alternative to formaldehyde for the purpose of dialyzer reuse. A reuse procedure that includes processing with RenNew-D is associated with improved biocompatibility, possibly because of maintenance of the blood-derived membrane coating established during prior dialysis.     

Beta 2-microglobulin kinetics in maintenance hemodialysis: a comparison of conventional and high-flux dialyzers and the effects of dialyzer reuse

beta 2-Microglobulin (beta 2M) forms synovial and bony amyloid deposits in long-term hemodialysis patients. To define the kinetics of beta 2M during hemodialysis and the effects of dialyzer reprocessing, we measured serum beta 2M, plasma C3a, and neutrophil counts immediately predialysis; 15, 90, and 180 minutes after beginning dialysis; and 15 minutes postdialysis in ten chronic hemodialysis patients. The studies were performed during first and third uses of cuprammonium rayon and polysulfone dialyzers processed by rinsing with water, then bleach, in an automated system (Seratronics DRS 4) and then packed in 1.5% formaldehyde. Mean serum beta 2M (corrected for ultrafiltration) decreased by 16.6% +/- 18.1% with new cuprammonium dialyzers and 57.1% +/- 12.8% with new polysulfone dialyzers. Dialyzer reprocessing had no significant effect on this decline. Predialysis serum beta 2M decreased by 30.4% +/- 15.5% 1 month after switching from cuprammonium to polysulfone dialyzers; these levels remained stable after 3 months of dialysis with polysulfone. Complement activation and neutropenia during dialysis were significantly more marked with cuprammonium, but were not affected by reprocessing of either dialyzer. In vitro adsorption of 124I-beta 2M to polysulfone fibers was greater than to cuprammonium; adsorption was not influenced by dialyzer reprocessing.     

Anaphylactoid reactions associated with reuse of hollow-fiber hemodialyzers and ACE inhibitors.

From July 18 through November 27, 1989, 12 anaphylactoid reactions (ARs) occurred in 10 patients at a hemodialysis center in Virginia. One patient required hospitalization; no patients died. ARs occurred within minutes of initiating dialysis and were characterized by peripheral numbness and tingling, laryngeal edema or angioedema, facial or generalized sensation of warmth, and/or nausea or vomiting. All 12 ARs occurred with dialyzers that had been reprocessed with an automated reprocessing system. A cohort study, including all patients undergoing dialysis sessions on the six days when an AR occurred, showed that the patients who experienced ARs were significantly more likely than patients who did not to be treated with angiotensin-converting enzyme (ACE) inhibitors (7/10 vs. 3/33; relative risk = 7.9; 95% confidence interval = 2.5 to 25.2) and to have been exposed to reused dialyzers rather than to new dialyzers (12/70 sessions vs. 0/31; P = 0.016). In those sessions using a reused dialyzer, the mean number of dialyzer uses in case-sessions was significantly higher than for noncase-sessions (10.3 vs. 6.2; P = 0.016). After reuse of dialyzers was discontinued at the center, no further ARs occurred, despite the continued administration of ACE inhibitors. This is the first report of an outbreak of ARs associated exclusively with reused dialyzers. We hypothesize that interactions between a dialyzer that has been repeatedly reprocessed and reused, blood, and additional factors, such as ACE inhibitors, increased the risk of developing ARs.     

Ethylene Oxide (ETO) as a Major Cause of Anaphylactoid Reactions in Dialysis (A review)

Ethylene oxide (ETO), an alkylating compound of high chemical reactivity, is widely used for gas sterilization, but recently serious ETO side reactions have been recognized. With chronic ETO exposure, increased spontaneous abortion, sister chromatid exchange, and leukemia are observed. After medical use of ETO outside nephrology, contact dermatitis, cardiopulmonary shock (during cardiopulmonary surgery), allergic local reactions to ETO sterilized lenses, and anaphylactoid reactions to ETO sterilized catheters have been described. In numerous dialysis patients widespread hypersensitivity to ETO has been documented by skin prick test and ETO radioallergosorbent test (RAST). Furthermore an anaphylactoid "first-use reaction" was described in dialyzed patients, most of whom were using hollow-fiber dialyzers. After long discussions whether complement activation versus hypersensitivity is the cause of such acute anaphylactoid reactions, more recent studies using either ETO RAST or basophil degranulation tests implicate ETO hypersensitivity as their major cause. The high prevalence of sensitization to ETO and the frequency, unpredictability, and potential danger of anaphylactoid reactions to ETO lead to the conclusion that ETO sterilization of dialyzers should be discontinued, since alternative modalities of sterilization are currently available.     

A Survey on Hypersensitivity Reactions in Hemodialysis

This survey was conducted from 1982 through 1984 by a cooperative effort among the Health Industries Manufacturers Association, seven dialyzer manufacturers, and the Food and Drug Administration. This article presents an analysis of the 1982-83 survey data and a summary of the 1984 data. Most of the reactions reported (99%) were associated with hollow-fiber dialyzers. About 50% of these reactions were experienced by patients using a dialyzer model for the first time, and greater than 98% of the reactions were related to new (unused) dialyzers. On average, there were 180 reactions reported per year, with greater than 90% being considered severe, including death, by the reporting center. A plot of the number of reactions versus time from 1982 through 1984 shows periods of 12-15 months in which the reaction rate remained practically constant. During these periods, the rate of reported reactions alternated from 60 to 150% of the average. Analysis of the survey data showed a strong correlation of the number of reactions with the race and age of the patients. Blacks and other minorities experience nearly three times as many reactions as white patients. Also, patients under 29 years of age seem to have nearly twice as many reactions as patients in the 30- to 49-year-old range, whereas patients over 50 years old have nearly half the number of reactions of the 30- to 49-year-old range. The average reactivity of the U.S. hemodialysis patient population was calculated to be 3.3 reactions per year per 1,000 patients exposed to hollow-fiber dialyzers and 0.3 reaction per year per 1,000 patients exposed to flat-plate dialyzers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ethylene Oxide in Dialyzer Rinsing Fluid: Effect of Rinsing Technique, Dialyzer Storage Time, and Potting Compound

Ethylene oxide (ETO) is recognized as one of the main causes of dialyzer-associated hypersensitivity reactions. We studied the amount of ETO in the rinsing fluid of ETO-sterilized hollow-fiber dialyzers as a function of rinsing technique, dialyzer storage time, and the amount of potting compound (known to be an ETO reservoir) in the dialyzer. The results suggested that the initial 500 ml of rinsing fluid removes much of the residual ETO in the dialyzer. Ethylene oxide extraction was enhanced substantially by rinsing at 37 degrees C versus 5 degrees C. However, considerable amounts of ETO remained in the dialyzer after an initial 500 ml rinse, some of which could be removed by rinsing with an additional 1,500 ml. High concentrations of ETO were measured in fluid that had been recirculated through the dialyzer for 10 min or longer and in fluid that had been allowed to remain in the dialyzer for 10 min under zero-flow conditions. The amount of ETO in the rinsing fluid decreased markedly as the dialyzer storage time was increased from 4 to 8 weeks and in dialyzers in which a portion of the potting compound had been replaced with a polycarbonate ring. Our results suggest that the dose of ETO administered to the patient at the outset of dialysis can be minimized by rinsing the dialyzer with 2 L of fluid at 37 degrees C and by avoiding administration of rinsing fluid that has been allowed to remain in contact with the dialyzer for more than several minutes. Use of a long storage interval and use of dialyzers containing reduced amounts of potting material will also reduce the ETO load.     

Anaphylactoid reactions in hemodialysis patients treated with the AN69 dialyzer.

During an 11 week period (May to July, 1990), we observed six anaphylactoid reactions (AR) in six different hemodialysis patients occurring at the onset of treatment with a new AN69 hollow-fiber dialyzer. Four patients required cardiopulmonary resuscitation and one of these expired. Four patients were also receiving an angiotensin converting enzyme (ACE) inhibitor while the other two were not on medication known to affect the renin-angiotensin system. Only patients treated with AN69 dialyzers were affected. A review of the literature indicated that out of 1087 patients reported, 72 patients were on the combination of an AN69 dialyzer and ACE inhibitor therapy and 41 (57%) demonstrated AR. Only two patients (0.4%; both from our series) treated with an AN69 dialyzer without ACE inhibitor therapy developed AR. AR did not occur in patients treated with a variety of other dialyzers during this 11 week period, with or without ACE inhibition. Possible causes for AR are discussed and include: (1.) blood-AN69 membrane interaction leading to the production of bradykinin and other vasodilators, the breakdown of which may be delayed by the presence of ACE inhibitors; (2.) hypersensitivity to ethylene oxide; (3.) passage of bacterial products from dialysate to blood; (4.) changes in membrane manufacturing specifications. Recommendations are proposed for the prevention and treatment of AR.     

Effect of dialyzer geometry on granulocyte and complement activation

During hemodialysis with cuprophan membranes, the complement system as well as leukocytes become activated. In order to clarify the role of dialyzer geometry, the effect of hollow-fiber versus flat-sheet dialyzers and of different surface areas on C3a generation and leukocyte degranulation was investigated. Plasma levels of leukocyte elastase in complex with alpha 1-proteinase inhibitor were significantly increased after 1 h (+55%) and 3 h (+62%) of hemodialysis with flat-sheet dialyzers as compared to hollow-fiber devices. In addition, plasma levels of lactoferrin, released from the specific granules of leukocytes during activation, were significantly higher (+42%) 3 h after the onset of dialysis treatment with flat-sheet than with hollow-fiber dialyzers. With respect to surface area, larger dialyzers tended to cause more release of leukocyte elastase as compared to dialyzers with smaller surface areas, irrespectively of the configuration of the dialyzer used. On the other hand, activation of the complement system, as measured by the generation of C3a-desarg, did not differ with both types of configurations. The same held true for leukopenia, which was almost identical for hollow-fiber and flat-sheet dialyzers. From these findings two lines of evidence emerge: First, not only the type of membrane material used in a dialyzer may influence its biocompatibility, but the geometry of the extracorporeal device also determines the degree of compatibility. Hence, the extent of leukocyte activation correlated with both configuration of the dialyzer and surface area of the membrane.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dialyzer Performance in the Clinic: Comparison of Six Low-Flux Membranes

The aim of this study is to assess the clinical performance of 6 different low-flux dialysis membranes under steady-state conditions in terms of urea and phosphate clearances. Ten stable hemodialysis patients were examined. The following dialyzers were studied, all in 1.5- to 1.6-m2 format: cuprammonium, cellulose acetate, cellulose diacetate, hemophane, polysulfone (low-flux), and polysynthane. The following parameters were examined: urea reduction ratio, phosphate reduction ratio, "instantaneous dialyzer clearance" for urea and phosphate, and total amount of urea and phosphate removed in the dialysate over a 1-week (three dialyses) period. Although there were differences between the membranes, all produced results within a narrow range. There was no one membrane that produced superior clearances in all categories. The cellulose acetate membrane was the least satisfactory membrane. Phosphate clearances were at best one third that of urea clearances. When choosing a low-flux dialysis membrane, urea and phosphate clearances are so similar amongst different membranes that other criteria are likely to have a greater influence on the choice of membrane.     

Role of Dialyzer Contaminants in the Allergic Epiphenomena of Hemodialysis

Abstract: Cuprophan hollow-fiber dialyzers contain contaminants including 1,2,3-propanetriol, carbohydrates, Limulus amebocyte lysate-reactive material, and particulates. In a clinical study, the role of these substances in the allergic-type response seen in some hemodialysis patients was examined. Patients were dialyzed three times per week for 6-week intervals with each of four dialyzer preparations designed to vary the burden of contaminants presented to the patient. Predialysis eosinophil counts and serum immunoglobulin (Ig) E levels were obtained weekly. White cell and platelet counts and plasma C3a and C5a levels were measured during dialysis for each dialyzer preparation. Dialyzer preparation had no effect on predialysis eosinophil counts or IgE levels. All patients demonstrated transient leukopenia and complement activation during dialysis, the magnitudes of which were unaffected by the type of dialyzer preparation. At the levels found in the dialyzers studied, it was questioned whether water-soluble extractables or particulates play any role in the allergic epiphenomena of hemodialysis.     

Residual Formaldehyde in Dialyzers: Quantity, Location, and the Effect of Different Methods of Rinsing

When formalin-sterilized dialyzers were rinsed by our standard technique (similar to that used in many other dialysis centres) undesirable concentrations of formaldehyde were found in the dialyzers at the start of dialysis. When the technique was modified by passing part of the saline through the blood compartment immediately before connection and discarding the saline left in the dialyzer at the time of connection, the concentration of formaldehyde infused into the patient fell below 2 μg/ml. However, the dialyzers still contained up to 13 mg of formaldehyde which leached slowly from the dialyzer during simulated dialysis. Some residual formaldehyde was found in several components of the dialyzer but the great majority was contained in the cellulose membrane.     

Computational Evaluation of Dialysis Fluid Flow in Dialyzers With Variously Designed Jackets

Dialyzer performance strongly depends on the flow of blood and dialysis fluid as well as membrane performance. It is necessary, particularly to optimize dialysis fluid flow, to develop a highly efficient dialyzer. The objective of the present study is to evaluate by computational analysis the effects of dialyzer jacket baffle structure, taper angle, and taper length on dialysis fluid flow. We modeled 10 dialyzers of varying baffle angles (0, 30, 120, 240, and 360°) with and without tapers. We also modeled 30 dialyzers of varying taper lengths (0, 12.5, 25.0, and 50.0 mm) and angles (0, 2, 4, and 6°) based on technical data of APS-SA dialyzers having varying surface areas of 0.8, 1.5, and 2.5 m² (Rexeed). Dialysis fluid flow velocity was calculated by the finite element method. The taper part was divided into 10 sections of varying fluid resistances. A pressure of 0 Pa was set at the dialysis fluid outlet, and a dialysis fluid flow rate of 500 mL/min at the dialysis fluid inlet. Water was used as the dialysis fluid in the computational analysis. Results for dialysis fluid flow velocity of the modeled dialyzers indicate that taper design and a fully surrounded baffle are important in making the dialysis fluid flow into a hollow-fiber bundle easily and uniformly. However, dialysis fluid flow channeling occurred particularly at the outflowing part with dialyzers having larger taper lengths and angles. Optimum design of dialysis jacket structure is essential to optimizing dialysis fluid flow and to increasing dialyzer performance.     

Mediation of Hypersensitivity Reactions During Hemodialysis by IgE Antibodies Against Ethylene Oxide

Sera from 329 hemodialysis patients, 46 of whom had experienced a hypersensitivity-type reaction during hemodialysis, were screened by an enzyme-allergosorbent test (EAST) for IgE antibodies specific for ethylene oxide (ETO). In seven of nine patients who had experienced a severe hypersensitivity reaction (type II or type III), high titers of IgE antibodies against ETO (greater than 3.0 PRU/mL) were found. However, plasma levels of IgE specific for ETO were in the normal range (less than 0.35 PRU/mL) in most (30/37) patients who had experienced a mild (type I) reaction. Selected sera from patients who had experienced severe reactions were further examined for IgE directed against isopropyl myristate (IPM), 2-chloroethanol, and extracts from unsterilized dialyzers. Importantly elevated serum levels of specific IgE against these substances could not be documented. Extracts of an ETO-sterilized, hollow-fiber dialyzer were positive, whereas extracts of an ETO-sterilized dialyzer containing a flat membrane were negative in the EAST. This difference can be explained by the different amounts of ETO present in the dialyzers. We conclude that ETO causes most severe hypersensitivity reactions by an IgE-mediated mechanism. On the other hand, the pathogenesis of mild (type I) reactions is less clearly associated with ETO allergy. Our results also suggest that other potentially allergenic substances in dialyzers (e.g., IPM, 2-chloroethanol) rarely induce specific IgE antibodies in dialysis patients.     

Outbreak of gram-negative bacteremia and pyrogenic reactions in a hemodialysis center

During the period from April 4, 1988, to April 20, 1988, nine pyrogenic reactions and five gram-negative bacteremias occurred in 11 patients undergoing dialysis. All pyrogenic reactions and gram-negative bacteremias occurred among patients in whom a reprocessed dialyzer was used. The rate of pyrogenic reactions or bacteremias per 100 sessions using a reprocessed dialyzer was higher than in sessions during which a new dialyzer was used (4.5 vs. 0; p = 0.03). Dialyzers were manually reprocessed with 2.5% Renalin germicide. The Renalin concentrations varied widely in 12 dialyzers stored after manual reprocessing during the epidemic period (0.9-4.2%); the median endotoxin concentrations varied from 0 to 246 ng/ml and were higher in dialyzers with Renalin concentrations less than or equal to 1.0% than in dialyzers with higher concentrations (p = 0.01). Experiments using a dilution technique described by a technician resulted in Renalin concentrations ranging from 1.4% at the surface to 3.5% at the bottom of the preparation container. These findings suggest that failure to adequately admix Renalin during dilution may be associated with low levels of disinfectant, high levels of bacteria and endotoxins in dialyzers, and outbreaks of pyrogenic reactions and gram-negative bacteremias in dialysis patients.     

Introduction: Incidence of Hypersensitivity in Hemodialysis

Abstract: Hypersensitivity reactions in hemodialysis are rare. They have been identified only recently, since the U.S. dialysis patient population became sufficiently large for pattern recognition. These reactions might be the result of a variety of factors, including the manufacturing process and patient characteristics. Some reactions may be due to components of the dialysis system other than the dialyzer, such as the tubing sets. Data collected by the Food and Drug Administration showed that in 1982 there were 3.5 severe hypersensitivity reactions per 100,000 hollow-fiber dialyzers sold. This rate of reaction occurrence does not appear to be appreciably different from that in previous years for which information, though scant, was available. Recently, a significant reduction in the rate of the reactions seems to have occurred after some U.S. manufacturers changed their manufacturing procedures.     

A case of anaphylactoid shock induced by the BS polysulfone hemodialyzer but not by the F8-HPS polysulfone hemodialyzer

A 57-year-old woman was admitted because of severe bradycardia and hypotension caused by an anti-arrhythmic agent and beta-blocker. For 19 months before admission, she had been undergoing hemodialysis with an F8-HPS polysulfone membrane hemodialyzer without any complications. In 2 dialysis sessions after admission, when a BS polysulfone membrane was used, she experienced anaphylactoid shock with severe hypotension leading to syncope, dyspnea and vomiting, just after the start of hemodialysis. After the anaphylactoid shock, her dialyzer membrane was changed to a cellulose triacetate membrane and she did not suffer from such attacks. This case indicates that severe anaphylactoid shock may be caused by a biocompatible dialyzer membrane and that the reactions of patients to each polysulfone membrane may differ among polysulfone membranes made by different manufacturers.     

Summary

This article discusses the first five Reports presented at the Symposium, those of Drs. Villarroel, Chenowith, Pearson and colleagues, and Henne and colleagues (two presentations). Although Dr. Villarroel Reported hypersensitivity reactions only during hollow-fiber dialysis, this may have been due to the way the information was gathered rather than accurately reflect actual happenings. The Report of the largest number of cases, to date, originated in England and came from a center that used mostly plate dialyzers. Thus, it is probable that any dialyzer may cause the syndrome, although more severe ones may be much more common in hollow-fiber dialyzers. Dr. Chenoweth observed that different membranes activate complement to differing extents but that all cellulosic membranes activate complement. Currently every patient experiences complement activation and neutropenia early in dialysis. It seems unlikely that a biological phenomenon that occurs in almost all dialyses is responsible for a reaction that occurs only in 35 of every 1,000,000 dialyses. Dr. Pearson and co-workers Reported the presence of Limulus amebocyte lysate-reactive material (LAL-RM) in 15 dialyzers tested with three different lysates. All dialyzers with cellulose-based membranes had positive tests with some, but not all, lysate reagents. Second, cell response tests indicative of pyrogenicity in humans were negative. At least two substances could be eluted from hollow-fiber dialyzers. One had a molecular weight of 23,000, the other of 3,100. Both could be inactivated by cellulase. These findings suggest that the LAL-RM is not an endotoxin. As the entire blood path of the dialyzer was rinsed, it is not possible to conclude whether or not the origin of LAL-RM is the headers, casings, or actual fibers. Drs. Henne, Schulze, and co-workers came to the same conclusion as Dr. Pearson; LAL-RM is of cellulosic origin, not an endotoxin. However, in a review of the composition of cotton fiber, the starting material for many dialysis membranes, it is of interest to note that it contains 1.5% protein and 0.6% wax. Perhaps these compounds should be investigated as possible causes of the severe allergic reaction in the rare patient who has it. Drs. Henne, Dietrich, and co-workers Reported on the difficulty of removing ethylene oxide from dialyzers. There are two first-order removal curves. One is for the fibers from which ethylene oxide washes out easily. The second is for the headers and casing. Ethylene oxide seems to be more firmly held in the latter; however much time is spent removing it, ethylene oxide will still leach out during the entire dialysis process. It is difficult to explain “first use syndrome“ allergic reaction by ethylene oxide hypersensitivity. If ethylene oxide were the common cause, one would expect the peak of reactions to occur after the patient had already been sensitized by previous blood transfusions and/or by ethylene oxide-cleaned equipment. Eosinophilia may be associated with the use of ethylene oxide. However, this symptom is not unique to first use syndrome but is a chronic problem with dialysis patients. Perhaps ethylene oxide is a cause of dialysis eosinophilia. This would explain why, in this author's experience, it is more common in hemodialysis patients, followed by continuous peritoneal dialysis (CCPD) patients, and finally by continuous ambulatory peritoneal dialysis patients, since the hemodialyzer exposes the patient to more ethylene oxide than in the tubing used in CCPD.     

Dialyzer reuse--part II: advantages and disadvantages

Although single dialyzer use and reuse by chemical reprocessing are both associated with some complications, there is no definitive advantage to either in this respect. Some complications occur mainly at the first use of a dialyzer: a new cellophane or cuprophane membrane may activate the complement system, or a noxious agent may be introduced to the dialyzer during production or generated during storage. These agents may not be completely removed during the routine rinsing procedure. The reuse of dialyzers is associated with environmental contamination, allergic reactions, residual chemical infusion (rebound release), inadequate concentration of disinfectants, and pyrogen reactions. Bleach used during reprocessing causes a progressive increase in dialyzer permeability to larger molecules, including albumin. Reprocessing methods without the use of bleach are associated with progressive decreases in membrane permeability, particularly to larger molecules. Most comparative studies have not shown differences in mortality between centers reusing and those not reusing dialyzers, however, the largest cluster of dialysis-related deaths occurred with single-use dialyzers due to the presence of perfluorohydrocarbon introduced during the manufacturing process and not completely removed during preparation of the dialyzers before the dialysis procedure. The cost savings associated with reuse is substantial, especially with more expensive, high-flux synthetic membrane dialyzers. With reuse, some dialysis centers can afford to utilize more efficient dialyzers that are more expensive; consequently they provide a higher dose of dialysis and reduce mortality. Some studies have shown minimally higher morbidity with chemical reuse, depending on the method. Waste disposal is definitely decreased with the reuse of dialyzers, thus environmental impacts are lessened, particularly if reprocessing is done by heat disinfection. It is safe to predict that dialyzer reuse in dialysis centers will continue because it also saves money for the providers. Saving both time for the patient and money for the provider were the main motivations to design a new machine for daily home hemodialysis. The machine, developed in the 1990s, cleans and heat disinfects the dialyzer and lines in situ so they do not need to be changed for a month. In contrast, reuse of dialyzers in home hemodialysis patients treated with other hemodialysis machines is becoming less popular and is almost extinct.