DIALYSIS, KIDNEY

Two principal therapies exist for patients who develop irreversible kidney failure and require renal replacement therapy to survive: kidney dialysis and kidney transplantation. The topic of kidney transplantation is addressed elsewhere in the Encyclopedia. This entry discusses kidney dialysis.

The two main techniques for kidney dialysis are hemodialysis and peritoneal dialysis. In hemodialysis, blood is pumped from a patient's body by a dialysis machine to a dialyzer—a filter composed of thousands of thin plastic membranes that uses diffusion to remove waste products—and then returned to the body. The time a hemodialysis treatment takes varies with the patient's size and remaining kidney function; most patients are treated for three and one-half to four and one-half hours three times a week in a dialysis unit staffed by nurses and technicians. In peritoneal dialysis, a fluid containing dextrose and electrolytes is infused into the abdominal cavity; this fluid, working by osmosis and diffusion, draws waste products from the blood into the abdominal cavity and then is drained from the abdominal cavity and discarded. Most patients on peritoneal dialysis perform four procedures at home daily about six hours apart to drain out the fluid with the accumulated wastes and instill two to two and one-half liters of fresh fluid. This technique is called continuous ambulatory peritoneal dialysis (CAPD). An automated form of peritoneal dialysis at home, called continuous cycling peritoneal dialysis (CCPD), is also available.

Both hemodialysis and peritoneal dialysis require a means to enter the body, called an access. In hemodialysis, access to the blood is obtained by removing blood through needles inserted into surgically created conduits, called fistulas or synthetic grafts, from arteries to veins. In peritoneal dialysis, access to the abdominal cavity is obtained with a plastic catheter, which is surgically implanted into the abdominal wall with the tip of the catheter positioned in the abdominal cavity.

Dialysis is a benefit to patients with severe kidney failure because it removes metabolic waste products and excess fluid, electrolytes, and minerals that build up in the blood when the kidneys are not functioning normally. Without the removal of these substances, patients become very weak, short of breath, and lethargic and eventually die. While dialysis is lifesaving for these patients and some can return to their prior level of functioning, most do not, because they do not feel well. Despite dialysis and medications, patients may experience anemia, bone pain and weakness, hypertension, heart disease, strokes, infections or clotting of the dialysis access, and bleeding. In addition to these medical problems, dialysis may impose other burdens on dialysis patients and their families, including extra costs for medications and for transportation to the dialysis center, loss of time spent in the treatments and travel to the dialysis center, and loss of control over the patient and family schedule to accommodate dialysis treatments. For these reasons, renal transplantation is considered to be the preferable form of treatment for severe kidney-failure patients who are able to undergo this major surgical procedure.

Kidney dialysis predates other life-sustaining therapies. In 1945 in the Netherlands, Willem Kolff first used hemodialysis to save the life of a woman with acute renal failure. In subsequent years, Kolff and others improved hemodialysis, but it could not be provided to patients with chronic, irreversible renal failure, or what has been called end-stage renal disease (ESRD), until 1960, when Dr. Belding Scribner of Seattle, Washington, used plastic tubes to form a shunt that could be left in an artery and vein for repeated dialysis access.

By most standards, kidney dialysis can be considered a very successful life-sustaining treatment. In the United States alone, since the inception of the Medicare-funded ESRD program in 1973, well over 1 million patients have had their lives sustained by dialysis, and at least some of them have survived for longer than twenty-five years. This program has been costly, however; in 1999, for example, the cost of keeping ESRD patients alive in the United States exceeded 17 billion dollars. Because dialysis preceded many other modern life-sustaining medical technologies, and because initially there was a scarcity of resources to pay for it, many of the ethical concerns subsequently discussed for other modern medical technologies were initially debated regarding dialysis: patient-selection criteria, rationing, access to care, the just allocation of scarce resources, the right to die (by having dialysis withheld or withdrawn), end-of-life care, and conflicts of interest (in dialysis unit ownership). This entry examines a number of these concerns in the United States ESRD program and compares them with those in other countries.

Patient-Selection Criteria and Overt Rationing

The first ethical concern to arise for physicians was how to select patients for dialysis. In the early 1960s in the United States, 10,000 people were estimated to be dying of renal failure every year, but there were not enough dialysis machines or trained physicians and nurses to treat these patients. Furthermore, the cost of treatment for one patient for one year, $15,000, was prohibitively expensive for most patients. Dialysis centers like the Seattle Artificial Kidney Center, founded in 1962, were able to treat only a small number of patients. It was therefore necessary to restrict the number of patients selected for dialysis; in other words, criteria had to be developed for the rationing of dialysis.

The problem of selecting patients had major ramifications because the patients denied access would die. The solution of the physicians of the Seattle dialysis center was to ask the county medical society to appoint a committee of seven laypersons to make the selection decisions for them from among persons they had identified as being medically appropriate. The doctors recognized that the selection decision went beyond medicine and would entail value judgments about who should have access to dialysis and be granted the privilege of continued life. Historian David Rothman says that their decision to have laypersons engaged in life-and-death decision making was the historic event that signaled the entrance of bioethics into medicine. Bioethics scholar Albert Jonsen believes that the field of bioethics emerged in response to these events in Seattle because they caused a nationwide controversy that stimulated the reflection of scholars regarding a radically new problem at the time, the allocation of scarce lifesaving resources.

The doctors regarded children and patients over the age of forty-five as medically unsuitable, but they gave the committee members no other guidelines with which to work. At first the committee members considered choosing patients by lottery, but they rejected this idea because they believed that difficult ethical decisions could be made about who should live and who should die. In the first few meetings, the committee members agreed on factors they would weigh in making their decisions: age and sex of the patient, marital status and number of dependents, income, net worth, emotional stability, educational background, occupation, and future potential. They also decided to limit potential candidates to residents of the state of Washington.

As the selection process evolved, a pattern emerged of the values the committee was using to reach its decisions. They weighed very heavily a person's character and contribution to society (Alexander).

Once public, the Seattle dialysis patient-selection process was subjected to harsh criticism. The committee was castigated for using middle-class American values and social-worth criteria to make decisions (Fox and Swazey). The selection process was felt to have been unfair and to have undermined American society's view of equality and the value of human life.

In 1972, lobbying efforts by nephrologists, patients, their families, and friends culminated in the passage by the U.S. Congress of Public Law 92–603 with Section 299I. This legislation classified patients with a diagnosis of ESRD as disabled, authorized Medicare entitlement for them, and provided the financial resources to pay for their dialysis. The only requirement for this entitlement was that the patients or their spouses or (if dependent children) parents were insured or entitled to monthly benefits under Social Security. The effect of this legislation was to virtually eliminate the need to ration dialysis.

When Congress passed this legislation, its members believed that money should not be an obstacle to providing lifesaving therapy (Rettig, 1976, 1991). Although the legislation stated that patients should be screened for appropriateness for dialysis and transplantation, the primary concern was to make dialysis available to those who needed it. Neither Congress nor physicians thought it necessary or proper for the government to determine patient-selection criteria.

By 1978, many U.S. physicians believed that it was morally unjustified to deny dialysis treatment to any patient with ESRD (Fox and Swazey). As a consequence, patients who would not previously have been accepted as dialysis candidates were started on treatment. A decade later, the first report of the U.S. Renal Data System documented the progressively greater acceptance rate of patients onto dialysis (U.S. Renal Data System), and subsequent reports have shown that the sharp rise in the number of dialysis patients could be explained in part by the inclusion of patients who had poor prognoses, especially the elderly and those with diabetic nephropathy (Hull and Parker). By 2000, of the new patients starting dialysis 48 percent were sixty-five years of age or older and 45 percent had diabetes as the cause of their ESRD.

Observers have raised concerns about the appropriateness of treating patients with a limited life expectancy and limited quality of life (Fox; Levinsky and Rettig). Specifically, questions have been raised about the appropriateness of providing dialysis to two groups of patients: those with a limited life expectancy despite the use of dialysis and those with severe neurological disease. The first group includes patients with kidney failure and other life-threatening illnesses, such as atherosclerotic cardiovascular disease, cancer, chronic pulmonary disease, and AIDS. The second group includes patients whose neurological disease renders them unable to relate to others, such as those in a persistent vegetative state or with severe dementia or cerebrovascular disease (Rettig and Levinsky).

The Institute of Medicine Committee for the Study of the Medicare End-Stage Renal Disease Program, which issued its report in 1991, acknowledged that the existence of the public entitlement for treatment of ESRD does not obligate physicians to treat all patients who have kidney failure with dialysis or transplantation (Levinsky and Rettig). For some kidney-failure patients, the burdens of dialysis may substantially outweigh the benefits; the provision of dialysis to these patients would violate the medical maxim: Be of benefit and do no harm. This committee recommended that guidelines be developed for identifying such patients and that the guidelines allow physicians discretion in assessing individual patients. Such guidelines might help nephrologists make decisions more uniformly, with greater ease, and in a way that promotes patient benefit and the appropriate use of dialysis resources. Subsequent studies have demonstrated that nephrologists differ on how they make decisions to start or stop dialysis for patients (Moss et al., 1993; Singer).

Access to Dialysis and the Just Allocation of Scarce Resources

The numbers of dialysis patients steadily grew each year, resulting in an ever increasing cost of the Medicare ESRD program. In the 1980s the United States experienced recordbreaking budget deficits, and questions began to be raised about continued federal funding for the ESRD program. Observers wondered if the money was well spent or if more good could be done with the same resources for other patients (Moskop).

Critics of the ESRD program observed that it satisfied neither of the first principles of distributive justice: equality and utility. On neither a macronor a microallocation level did the ESRD program provide equality of access. On the macroallocation level, observers asked, as a matter of fairness and equality, why the federal government should provide almost total support for one group of patients with end-stage disease—those with ESRD—and deny such support to those whose failing organs happened to be hearts, lungs, or livers (Moskop; Rettig, 1991). On a microallocation level, only 93 percent of patients with ESRD have been eligible for Medicare ESRD benefits. The poor and ethnic minorities are thought to constitute most of the ineligible. The Institute of Medicine Committee for the Study of the Medicare End-Stage Renal Disease Program recommended that the U.S. Congress extend Medicare entitlement to all citizens and resident aliens with ESRD (Rettig and Levinsky).

From a utilitarian perspective, the ESRD program could not be argued to be maximizing the good for the greatest number. In the 1980s, more than 5 percent of the total Medicare budget was being spent on dialysis and transplant patients, who represented less than 0.2 percent of the active Medicare patient population. A similar disproportionate expense has continued into the twenty-first century. Furthermore, while in 2000 more than 40 million Americans were without basic health insurance, the cost to treat one ESRD patient on dialysis—of whom there were over 300,000—exceeded $50,000 per year. Despite the high cost, ESRD patient unadjusted one-year mortality approached 25 percent; for many, as Anita Dottes noted, life on dialysis was synonymous with physical incapacitation, dependency, chronic depression, and disrupted family functioning (Dottes).

Withholding and Withdrawing Dialysis

After cardiovascular diseases and infections, withdrawal from dialysis is the third most common cause of dialysis-patient death. In one large study, dialysis withdrawal accounted for 22 percent of deaths (Neu and Kjellstrand). Older patients and those with diabetes have been found to be most likely to stop dialysis. Over time, as the percentage of diabetic and older patients (those sixty-five or over) on dialysis increased, withdrawal from dialysis became more common. According to surveys of dialysis units performed in the 1990s, most dialysis units had withdrawn one or more patients from dialysis in the preceding year with the mean being three. (Moss et al., 1993).

Because of the increased frequency of decisions to withhold and withdraw dialysis in the 1980s and 1990s, the clinical practices of nephrologists in reaching these decisions with patients and families generated heightened interest. Discussions of the ethics and process of withholding or withdrawing dialysis became more frequent (Hastings Center, U.S. President's Commission). Two ethical justifications were given for withholding or withdrawing dialysis: the patient's right to refuse dialysis, which was based on the right of self-determination, and an unfavorable balance of benefits to burdens to the patient that continued life with dialysis would entail. Nephrologists and ethicists recommended that decisions to start or stop dialysis be made on a case-by-case basis, because individual patients evaluate benefits and burdens differently. They noted that such decisions should result from a process of shared decision making between the nephrologist and the patient with decision-making capacity. If the patient lacked decision-making capacity, the decisions should be made on the basis of the patient's expressed wishes (given either verbally or in a written advance directive) or, if these were unknown, the patient's best interests. They also advised that in such cases a surrogate be selected to participate with the physician in making decisions for the patient.

Questions were identified to help nephrologists evaluate a patient's request to stop dialysis. For example, why does the patient want to stop? Does the patient mean what he or she says and say what he or she means? Does the patient have decision-making capacity, or is his or her capacity altered by depression, encephalopathy, or another disorder? Are there any changes that can be made that might improve life on dialysis for the patient? How do the patient's family and close friends view his or her request? Would the patient be willing to continue on dialysis while factors responsible for the patient's request to stop are addressed?

If, after patient evaluation based on these questions, the patient still requested discontinuation of dialysis, nephrologists were counseled to honor the competent patient's request. In several studies, nine out of ten nephrologists indicated that they would stop dialysis at the request of a patient with decision-making capacity (Moss et al., 1993; Singer).

In half or more of the cases in which decisions have been made to withdraw dialysis, patients have lacked decisionmaking capacity. Nephrologists have expressed a willingness to stop dialysis of irreversibly incompetent patients who had clearly said they would not want dialysis in such a condition, but they have disagreed about stopping dialysis in patients without clear advance directives (Singer). In general, there has been a presumption in favor of continued dialysis for patients who cannot or have not expressed their wishes. The patient's right to forgo dialysis in certain situations has therefore usually been difficult to exercise.

The Patient Self-Determination Act, which applied to institutions participating in Medicare and Medicaid and which became effective December 1, 1991, was intended to educate healthcare professionals and patients about advance directives and to encourage patients to complete them. Although the ESRD program is almost entirely funded by Medicare, dialysis units were inadvertently left out of the act. Nonetheless, the completion of advance directives by dialysis patients has been specifically recommended for three reasons: (1) the elderly, who constitute roughly half of the dialysis population, are those who are most likely to withdraw or be withdrawn from dialysis; (2) dialysis patients have a significantly shortened life expectancy compared to non-renal patients; and (3) unless an advance directive to withhold cardiopulmonary resuscitation (CPR) is given, it will automatically be provided, and CPR rarely leads to extended survival in dialysis patients (Moss et al., 1992).

When patients lack decision-making capacity and have not completed advance directives, ethically complex issues may arise in the decision whether to start or stop dialysis. Many nephrologists have indicated that they would consult an ethics committee, if available, for assistance in making decisions in different cases (Moss et al., 1993). Ethics consultations are most frequently requested for decisions regarding the withholding or withdrawing of life-sustaining therapy such as dialysis.

By the end of the twentieth century, nephrologists recognized the need for a guideline on starting and stopping dialysis. Such a guideline, which would address appropriateness of patients for dialysis (patient-selection criteria), had been recommended by the Institute of Medicine Committee for the Study of the Medicare ESRD Program almost a decade earlier. In a 1997 survey of the American Society of Nephrology (ASN) and the Renal Physicians Association (RPA) leadership, the respondents gave the highest priority among twenty-four choices to the development of an evidencebased clinical practice guideline on starting and stopping dialysis. In the context of a changing patient population, the RPA and ASN leaderships believed that an evidence-based clinical practice guideline would assist patients, families, and the nephrology team in making difficult decisions about initiating, continuing, and stopping dialysis. The resultant clinical practice guideline, Shared Decision-Making in the Appropriate Initiation of and Withdrawal from Dialysis, was developed by a working group of physicians, nurses, social workers, patients, dialysis administrators, a bioethicist, and a health policy expert (RPA and ASN, 2000). The objectives for the guideline were to:

• Synthesize available research evidence on patients with acute renal failure and ESRD as a basis for making recommendations about withholding and withdrawing dialysis;
• Enhance understanding of the principles and processes useful for and involved in making decisions to withhold or withdraw dialysis;
• Promote ethically as well as medically sound decision-making in individual cases;
• Recommend tools that can be used to promote shared decision-making in the care of patients with acute renal failure or ESRD;
• Offer a publicly understandable and acceptable ethical framework for shared decisionmaking among healthcare providers, patients, and their families.

The guideline makes nine recommendations. These recommendations encourage the process of shared decisionmaking, the obtaining of informed consent or refusal for dialysis, estimating prognosis as part of informed dialysis decision-making, systematic approaches to conflict resolution, the use and honoring of advance directives, withholding or withdrawing dialysis for patients under certain circumstances, the use of time-limited trials to assist in reaching decisions about continuing or stopping dialysis, and the use of palliative care for ESRD patients who decide to forgo dialysis. By defining the appropriate use of dialysis and the process to be used in making dialysis decisions, this guideline should also prove to be very useful to ethics consultants when they are called to help resolve conflicts over starting or stopping dialysis (Moss).

End-of-Life Care

In the wake of public dissatisfaction with end-of-life care and efforts to legalize physician-assisted suicide in several states, physician groups, including the RPA and ASN, recognized their ethical responsibility to improve end-of-life care for their patients. In 1997 in a joint position statement on Quality Care at the End of Life, the RPA and the ASN urged nephrologists and others involved in the care of ESRD patients to obtain education and skills in palliative care. They noted that palliative care knowledge and skills were especially important for nephrologists because they treat ESRD patients who die from complications despite the continuation of dialysis or after withholding or withdrawing dialysis. For example, in 1999, 48,000 patients died from complications while continuing dialysis and 12,000 died after a decision to stop dialysis.

One issue unresolved in the 1997 position statement was whether cardiopulmonary resuscitation ought always to be provided if cardiac arrest were to occur while patients are receiving dialysis, even if individual dialysis patients preferred not to undergo it. Data suggested that as many as one-third of dialysis units performed cardiopulmonary resuscitation on all patients who arrested while on dialysis, including those who refused the procedure. The concerns driving the uniform resuscitation of dialysis patients were two: The cardiac arrest might be iatrogenic, i.e., due to a complication of the dialysis procedure; and other patients might be troubled if the dialysis team made no attempt at cardiopulmonary resuscitation.

In 1999 the Robert Wood Johnson Foundation convened a series of workgroups to evaluate how end-of-life care could be improved for special populations of patients. The Robert Wood Johnson Foundation included the ESRD population because they perceived a readiness to address end-of-life care issues among the healthcare professionals treating ESRD patients.

In its report the ESRD workgroup noted that

most patients with end-stage renal disease, especially those who are not candidates for renal transplantation, have a significantly shortened life expectancy. In the United States, dialysis patients live about one-third as long as non-dialysis patients of the same age and gender. The unadjusted five-year probability of survival for all incident ESRD patients is only 39 percent; and for the 48 percent of incident ESRD patients who are 65 years of age or older, it is only 18 percent. Life expectancy is also shortened by comorbid conditions. 45 percent of new ESRD patients have diabetes, and many have other comorbid conditions including hypertension, congestive heart failure, ischemic heart disease, and peripheral vascular disease.… It is clear from the foregoing information that the care of ESRD patients requires expertise not only in the medical and technical aspects of maintaining patients on dialysis, but also in palliative care—encompassing pain and symptom management, advance care planning, and attention to ethical, psychosocial, and spiritual issues related to starting, continuing, withholding, and stopping dialysis. (p. 5)

The ESRD workgroup noted the following with regard to the unresolved issue of cardiopulmonary resuscitation in the dialysis unit: (1) research studies of cardiopulmonary resuscitation have indicated that the outcomes for ESRD patients are poor; (2) most dialysis patients express a preference for undergoing cardiopulmonary resuscitation, but over 90 percent believe that a dialysis patient's wish not to undergo cardiopulmonary resuscitation should be respected by dialysis unit personnel (Moss et al., 2001); and (3) it is necessary for nephrologists and other members of the renal team to educate dialysis patients about the likely outcome of cardiopulmonary resuscitation based on patients' particular medical conditions. They recommended that "dialysis units should adopt policies regarding cardiopulmonary resuscitation in the dialysis unit that respect patients' rights of self-determination, including the right to refuse cardiopulmonary resuscitation and to have a do-not-resuscitate order issued and honored" (Robert Wood Johnson Foundation, p. 10). The RPA and the ASN accepted this recommendation and revised their position statement on Quality Care at the End of Life in 2002 to include this and other recommendations of the ESRD workgroup.

The Effect of Reimbursement

Reimbursement has affected both dialysis techniques and quality of care provided to dialysis patients. In the 1980s cost was the federal policymakers' primary concern about the ESRD program, and federal reimbursement rates for dialysis were reduced twice. By 1989, the average reimbursement rate—adjusted for inflation—for freestanding dialysis units was 61 percent lower than it had been when the program began (Rettig and Levinsky).

When the U.S. Congress established the Medicare ESRD program, the highest estimate for cost of the program by 1977 was $250 million; the actual cost was approximately $1 billion (Fox and Swazey). At least two major reasons were held to be responsible for the higher cost: the increasing number of patients being started on dialysis, some of whom would have been unthinkable dialysis candidates ten years earlier, and the growth of in-center dialysis while the use of less costly home dialysis declined.

Despite inflation and increases in the costs of salaries, equipment, and supplies, there were only two modest increases in the Medicare reimbursement to dialysis providers in the 1990s. By the end of the twentieth century, the rate of reimbursement for dialysis by Medicare adjusted for inflation was only one-third of the amount in 1973. A longstanding historian of the ESRD program, Richard Rettig, observed, "No other part of Medicare has been subjected to this severe, even punitive, economic discipline" (2001, p. 16). Meanwhile, the incidence of ESRD in the United States had tripled compared to twenty years earlier. Almost 100,000 new patients were starting dialysis each year.

Conflicts of Interest

A conflict of interest occurs when there is a clash between a physician's personal financial gain and the welfare of his or her patients. While a conflict of interest generally exists for all physicians who practice fee-for-service medicine, there is a potentially greater conflict of interest for physicians who share in the ownership of for-profit dialysis units in which they treat patients. Physicians who receive a share of the profits are financially rewarded for reducing costs. Although measures to reduce costs may simply lead to greater efficiency, they may also compromise patient welfare if they entail decreasing dialysis time; purchasing cheaper, possibly less effective dialyzers and dialysis machines; and hiring fewer registered nurses, social workers, and dietitians. In the past, for-profit dialysis companies were quite open about their policy of giving physicians a financial stake in their companies. Such companies flourished under the ESRD program (Kolata).

Physicians and dialysis units are paid on a per-patient and per-treatment basis, respectively, under the ESRD program, and the acceptance rate of patients to dialysis in the United States is higher than anywhere else in the world (Hull and Parker). This higher rate has been at least partly attributed to the acceptance on dialysis in the United States of a much greater number of patients with poor prognoses. Some have argued that this high acceptance rate was a sign that nephrologists and dialysis units were seeking to maximize their incomes, while others have commented that many physicians believed they were obligated to dialyze all patients with ESRD who wanted it (Fox).

In the 1990s, the concerns about conflicts of interest heightened. Two-thirds of ESRD patients were being dialyzed in for-profit units. Short dialysis times were found disproportionately in for-profit units and associated with increased mortality. Patients treated in for-profit dialysis units were noted to have a 20 percent higher mortality rate and a referral rate for renal transplantation 26 percent lower than that for not-for-profit units (Levinsky). The nephrologist who owned all or a share of a for-profit unit was confronted with a clear conflict of interest. In responding to financial pressures created by a dialysis reimbursement rate that failed to keep up with inflation and in instituting cost-cutting measures, he or she was believed to be treading a very fine line between maintaining adequate profit to keep the dialysis unit open and compromising patient care.

A decade earlier, nephrologist and New England Journal of Medicine editor Arnold Relman had anticipated the predicament nephrologist owners of dialysis units would face. He had warned that the private enterprise system—the so-called new medical-industrial complex—had a particularly striking effect on the practice of dialysis, and he urged physicians to separate themselves totally from any financial participation so as to maintain their integrity as professionals (Relman). Education of nephrologists about these issues, both in training and in continuing education courses, was advocated to help them to identify present and potential conflicts of interest and resolve them in a way that places patients' interests first.

To hold dialysis units, both for-profit and non-profit, accountable for the quality of care they provide, the Medicare ESRD program through the eighteen ESRD Networks established quality indicators to measure the performance of individual dialysis units and all the dialysis units within a region. These measures monitor adequacy of dialysis, anemia management, vascular access placement, and standardized mortality ratios as well as other indicators.

Racial Disparities

Racial differences in access to effective medical procedures are known to be a problem in the United States. Black patients are less likely than white patients to undergo renal transplantation, coronary artery bypass surgery, and many other procedures. Despite the tendency to undertreatment in other areas, black patients are significantly overrepresented in the dialysis population, comprising 32 percent of all ESRD patients but only 13 percent of the United States population. There is also an overrepresentation of other racial and ethnic minority groups in the ESRD population. The increased susceptibility of nonwhite populations to ESRD has not been fully explained and probably represents a complex interaction of genetic, cultural, and environmental influences. Disparities in treatment for racial minority ESRD patients have been noted, including the following:(1) they are less likely to be referred for home dialysis and renal transplantation; (2) they are more likely to be underdialyzed; and (3) they are more likely to have less desirable synthetic grafts (shorter patency and more complications) rather than fistulas as permanent dialysis access. Nonetheless, blacks have better survival and quality of life compared to whites, and they are also less likely to withdraw from dialysis. The better outcomes despite less than optimal treatment present an opportunity to study and further improve ESRD care for minority patients.

International Perspective

Economics plays the leading role in determining the availability of dialysis in countries throughout the world. The countries with the largest numbers of patients on dialysis are among the richest: the United States, Japan, and Germany. The number of patients per million population treated with dialysis correlates highly with the gross national product per capita. Countries with a per capita gross national product of less than $3,000 per year treat a negligible number of patients with dialysis and transplantation. Approximately three-quarters of the world's population live in these poorer countries.

In parts of the world where dialysis technology and money for healthcare are limited, dialysis is severely rationed. Two sets of criteria have been used to select patients for dialysis. In India, China, Egypt, Libya, Tunisia, Algeria, Morocco, Kenya, and South Africa, money and political influence play an important role in deciding which patients will have access to dialysis and transplantation. In Eastern Europe, ESRD patients with primary renal disease who have a lower mortality and who are more likely to be rehabilitated tend to be selected (Kjellstrand and Dossetor).

Conclusion

Dialysis was one of the earliest life-sustaining treatments. Since its inception, dialysis has raised many ethical issues to be analyzed and resolved. In the 1960s the attempt to make difficult yet socially acceptable ethical decisions about patient-selection criteria and the rationing of dialysis failed because of the use of social worth criteria. The dialysis community and others learned from this experience. In the 1990s, prompted by the dramatic expansion of the ESRD program and a belief by many that not all patients on dialysis were appropriate for it, the renal professional societies succeeded in developing patient-selection criteria—based on likelihood of benefit and shared decision making—that have been widely endorsed. Other examples of analyzed and resolved ethical issues in dialysis that are broadly applicable are the ethical justifications for allowing patients to forgo dialysis, a life-sustaining treatment, and the development of an approach to hold providers accountable when there is a major and continuing conflict of interest.

Kidney dialysis has succeeded beyond all expectations in its ability to sustain life for hundreds of thousands of patients worldwide. Refinements in the technology have allowed patients who were previously considered not to be candidates for dialysis to experience several or more years of extended life. Its success brings with it three major challenges: how to finance the expensive treatments for a larger and larger number of patients; how to maintain the quality of dialysis care in the United States with the provision of dialysis increasingly being provided by for-profit dialysis corporations who have an inherent conflict of interest; and how to humanely care for an increasingly older, frail population with multiple medical problems and a significantly shortened life expectancy.

Because of the continuing challenges it poses, dialysis will likely continue to break new ground with regard to ethical analyses that will subsequently be helpful to other modern medical technologies.

alvin h. moss (1995)

revised by author

SEE ALSO: Artificial Hearts and Cardiac Assist Devices; Biomedical Engineering; Body; Cybernetics; Healthcare Resources; Life, Quality of; Lifestyles and Public Health; Life Sustaining Treatment and Euthanasia; Medicaid; Organ and Tissue Procurement; Organ Transplants; Technology; Xenotransplantation

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Rettig, Richard A., and Levinsky, Norman G. 1991. Kidney Failure and the Federal Government. Washington, D.C.: National Academy Press.

Robert Wood Johnson Foundation Promoting Excellence in End-of-Life Care Program. 2002. End-Stage Renal Disease Workgroup Recommendations to the Field. Princeton, NJ: Author.

Rothman, David J. 1991. Strangers at the Bedside: A History of How Law and Bioethics Transformed Medical Decision Making. New York: Basic Books.

Singer, Peter A. 1992. "Nephrologists' Experience with and Attitudes Towards Decisions to Forego Dialysis: The End-Stage Renal Disease Network of New England." Journal of the American Society of Nephrology 2(7): 1235–1240.

U.S. President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. 1983. Deciding to Forego Life-Sustaining Treatment: A Report on the Ethical, Medical, and Legal Issues in Treatment Decisions. Washington, D.C.: U.S. Government Printing Office.

U.S. Renal Data System. 1989. Annual Data Report, 1989. Bethesda, MD: National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Division of Kidney, Urologic, and Hematologic Diseases.

Dialysis, Kidney

Definition

Dialysis treatment replaces the function of the kidneys, which normally serve as the body's natural filtration system. Through the use of a blood filter and a chemical solution known as dialysate, the treatment removes waste products and excess fluids from the bloodstream, while maintaining the proper chemical balance of the blood. There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Purpose

Dialysis can be used in the treatment of patients suffering from poisoning or overdose, in order to quickly remove drugs from the bloodstream. Its most prevalent application, however, is for patients with temporary or permanent kidney failure. For patients with end-stage renal disease (ESRD), whose kidneys are no longer capable of adequately removing fluids and wastes from their body or of maintaining the proper level of certain kidney-regulated chemicals in the bloodstream, dialysis is the only treatment option available outside of kidney transplantation. In 1996 in the United States, over 200,000 people underwent regular dialysis treatments to manage their ESRD.

Precautions

Blood pressure changes associated with hemodialysis may pose a risk for patients with heart problems. Peritoneal dialysis may be the preferred treatment option in these cases.

Peritoneal dialysis is not recommended for patients with abdominal adhesions or other abdominal defects, such as a hernia, that might compromise the efficiency of the treatment. It is also not recommended for patients who suffer frequent bouts of diverticulitis, an inflammation of small pouches in the intestinal tract.

Description

There are two types of dialysis treatment: hemodialysis and peritoneal dialysis:

Hemodialysis

Hemodialysis is the most frequently prescribed type of dialysis treatment in the United States. The treatment involves circulating the patient's blood outside of the body through an extracorporeal circuit (ECC), or dialysis circuit. Two needles are inserted into the patient's vein, or access site, and are attached to the ECC, which consists of plastic blood tubing, a filter known as a dialyzer (artificial kidney), and a dialysis machine that monitors and maintains blood flow and administers dialysate. Dialysate is a chemical bath that is used to draw waste products out of the blood.

Since the 1980s, the majority of hemodialysis treatments in the United States have been performed with hollow fiber dialyzers. A hollow fiber dialyzer is composed of thousands of tube-like hollow fiber strands encased in a clear plastic cylinder several inches in diameter. There are two compartments within the dialyzer (the blood compartment and the dialysate compartment). The membrane that separates these two compartments is semipermeable. This means that it allows the passage of certain sized molecules across it, but prevents the passage of other, larger molecules. As blood is pushed through the blood compartment in one direction, suction or vacuum pressure pulls the dialysate through the dialysate compartment in a countercurrent, or opposite direction. These opposing pressures work to drain excess fluids out of the bloodstream and into the dialysate, a process called ultrafiltration.

A second process called diffusion moves waste products in the blood across the membrane into the dialysate compartment, where they are carried out of the body. At the same time, electrolytes and other chemicals in the dialysate solution cross the membrane into the blood compartment. The purified, chemically balanced blood is then returned to the body.

Most hemodialysis patients require treatment three times a week, for an average of three-four hours per dialysis "run." Specific treatment schedules depend on the type of dialyzer used and the patient's current physical condition. While the treatment prescription and regimen is usually overseen by a nephrologist (a doctor that specializes in the kidney), dialysis treatments are typically administered by a nurse or patient care technician in outpatient clinics known as dialysis centers, or in hospital-based dialysis units. In-home hemodialysis treatment is also an option for some patients, although access to this type of treatment may be limited by financial and lifestyle factors. An investment in equipment is required and another person in the household should be available for support and assistance with treatments.

Peritoneal dialysis

In peritoneal dialysis, the patient's peritoneum, or lining of the abdomen, acts as a blood filter. A catheter is surgically inserted into the patient's abdomen. During treatment, the catheter is used to fill the abdominal cavity with dialysate. Waste products and excess fluids move from the patient's bloodstream into the dialysate solution. After a waiting period of six to 24 hours, depending on the treatment method used, the waste-filled dialysate is drained from the abdomen, and replaced with clean dialysate.

There are three types of peritoneal dialysis:

• Continuous ambulatory peritoneal dialysis (CAPD). A continuous treatment that is self-administered and requires no machine. The patient inserts fresh dialysate solution into the abdominal cavity, waits four to six hours, and removes the used solution. The solution is immediately replaced with fresh dialysate. A bag attached to the catheter is worn under clothing.
• Continuous cyclic peritoneal dialysis (CCPD). An overnight treatment that uses a machine to drain and refill the abdominal cavity, CCPD takes 10-12 hours per session.
• Intermittent peritoneal dialysis (IPD). This hospital-based treatment is performed several times a week. A machine administers and drains the dialysate solution, and sessions can take up to 24 hours.

Peritoneal dialysis is often the treatment option of choice in infants and children, whose small size can make vascular (through a vein) access difficult to maintain. Peritoneal dialysis can also be done outside of a clinical setting, which is more conducive to regular school attendance.

Preparation

Patients are weighed immediately before and after each hemodialysis treatment to assess their fluid retention. Blood pressure and temperature are taken and the patient is assessed for physical changes since their last dialysis run. Regular blood tests monitor chemical and waste levels in the blood. Prior to treatment, patients are typically administered a dose of heparin, an anticoagulant that prevents blood clotting, to ensure the free flow of blood through the dialyzer and an uninterrupted dialysis run for the patient.

Aftercare

Both hemodialysis and peritoneal dialysis patients need to be vigilant about keeping their access sites and catheters clean and infection-free during and between dialysis runs.

Dialysis is just one facet of a comprehensive treatment approach for ESRD. Although dialysis treatment is very effective in removing toxins and fluids from the body, there are several functions of the kidney it cannot mimic, such as regulating high blood pressure and red blood cell production. Patients with ESRD need to watch their diet and fluid intake carefully and take medications as prescribed to manage their disease.

Risks

Many of the risks and side effects associated with dialysis are a combined result of both the treatment and the poor physical condition of the ESRD patient. Dialysis patients should always report side effects to their healthcare provider.

Anemia

Hematocrit (Hct) levels, a measure of red blood cells, are typically low in ESRD patients. This deficiency is caused by a lack of the hormone erythropoietin, which is normally produced by the kidneys. The problem is elevated in hemodialysis patients, who may incur blood loss during hemodialysis treatments. Epoetin alfa, or EPO (sold under the trade name Epogen), a hormone therapy, and intravenous or oral iron supplements are used to manage anemia in dialysis patients.

Cramps, nausea, vomiting, and headaches

Some hemodialysis patients experience cramps and flu-like symptoms during treatment. These can be caused by a number of factors, including the type of dialysate used, composition of the dialyzer membrane, water quality in the dialysis unit, and the ultrafiltration rate of the treatment. Adjustment of the dialysis prescription often helps alleviate many symptoms.

Hypotension

Because of the stress placed on the cardiovascular system with regular hemodialysis treatments, patients are at risk for hypotension, a sudden drop in blood pressure. This can often be controlled by medication and adjustment of the patient's dialysis prescription.

Infection

Both hemodialysis and peritoneal dialysis patients are at risk for infection. Hemodialysis patients should keep their access sites clean and watch for signs of redness and warmth that could indicate infection. Peritoneal dialysis patients must follow the same precautions with their catheter. Peritonitis, an infection of the peritoneum, causes flu-like symptoms and can disrupt dialysis treatments if not caught early.

Infectious diseases

Because there is a great deal of blood exposure involved in dialysis treatment, a slight risk of contracting hepatitis B and hepatitis C exists. The hepatitis B vaccination is recommended for most hemodialysis patients. As of 1997, there had only been one documented case of HIV being transmitted in a United States dialysis unit to a staff member, and no documented cases of HIV ever being transmitted between dialysis patients in the United States. The strict standards of infection control practiced in modern hemodialysis units makes the chance of contracting one of these diseases very small.

Normal results

Puffiness in the patient related to edema, or fluid retention, may be relieved after dialysis treatment. The patient's overall sense of physical well-being may also be improved. Because dialysis is an ongoing treatment process for many patients, a baseline for normalcy can be difficult to gauge.

Resources

ORGANIZATIONS

American Association of Kidney Patients. 100 S. Ashley Dr., #280, Tampa, FL 33602. (800) 749-2257. 〈http://www.aakp.org〉.

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800) 638-8299. 〈http://216.248.130.102/Default.htm〉.

National Kidney Foundation. 30 East 33rd St., New York, NY 10016. (800) 622-9010. 〈http://www.kidney.org〉.

United States Renal Data System (USRDS). The University of Michigan, 315 W. Huron, Suite 240, Ann Arbor, MI 48103. (734) 998-6611. 〈http://www.med.umich.edu/usrds〉.

KEY TERMS

Access site— The vein tapped for vascular access in hemodialysis treatments. For patients with temporary treatment needs, access to the bloodstream is gained by inserting a catheter into the subclavian vein near the patient's collarbone. Patients in long-term dialysis require stronger, more durable access sites, called fistulas or grafts, that are surgically created.

Dialysate— A chemical bath used in dialysis to draw fluids and toxins out of the bloodstream and supply electrolytes and other chemicals to the bloodstream.

Dialysis prescription— The general parameters of dialysis treatment that vary according to each patient's individual needs. Treatment length, type of dialyzer and dialysate used, and rate of ultrafiltration are all part of the dialysis prescription.

Dialyzer— An artificial kidney usually composed of hollow fiber which is used in hemodialysis to eliminate waste products from the blood and remove excess fluids from the bloodstream.

Erythropoietin— A hormone produced by the kidneys that stimulates the production of red blood cells by bone marrow.

ESRD— End-stage renal disease; chronic or permanent kidney failure.

Extracorporeal circuit (ECC)— The path the hemodialysis patient's blood takes outside of the body. It typically consists of plastic tubing, a hemodialysis machine, and a dialyzer.

Hematocrit (Hct) level— A measure of red blood cells.

Peritoneum— The abdominal cavity; the peritoneum acts as a blood filter in peritoneal dialysis.

Kidney Dialysis

Definition
Purpose
Demographics
Description
Diagnosis/Preparation
Aftercare
Risks
Normal results
Morbidity and mortality rates
Alternatives

Definition

Dialysis treatment replaces the function of the kidneys, which normally serve as the body’s natural filtration system. Through the use of a blood filter and a chemical solution known as dialysate, the treatment removes waste products and excess fluids from the bloodstream, while maintaining the proper chemical balance of the blood. There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Purpose

Dialysis is most commonly prescribed for patients with temporary or permanent kidney failure. People with end-stage renal disease (ESRD) have kidneys that are no longer capable of adequately removing fluids and wastes from their body or of maintaining the proper level of certain kidney-regulated chemicals in the bloodstream. For these individuals, dialysis is the only treatment option available outside of kidney transplantation. Dialysis may also be used to simulate kidney function in patients awaiting a transplant until a donor kidney becomes available. Also, dialysis may be used in the treatment of patients suffering from poisoning or overdose in order to quickly remove drugs from the bloodstream.

Demographics

As of 2003, in the United States, over 287,494 people were undergoing regular dialysis treatments to manage their ESRD. Diabetes mellitus is the leading single cause of ESRD: 40% of dialysis patients in the United States have ESRD caused by diabetes, 28% by hypertension, 11.6% by glomerulonephritis, and 4.7% by cystic (bladder) or other urologic conditions.

Among children and young adults under 20 on dialysis, glomerulonephritis is the leading cause of ESRD (31%), and hereditary, cystic, and congenital diseases account for 37%. Pediatric patients typically spend less time on dialysis than adults; according to the USRDS the average waiting period for a kidney transplant for patients under age 20 is 10 months, compared to the adult wait of approximately two years.

Description

There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Hemodialysis

Hemodialysis is the most frequently prescribed type of dialysis treatment in the United States. The treatment involves circulating the patient’s blood outside of the body through an extracorporeal circuit (ECC), or dialysis circuit. Two needles are inserted into the patient’s vein, or access site, and are attached to the ECC, which consists of plastic blood tubing, a filter known as a dialyzer (artificial kidney), and a dialysis machine that monitors and maintains blood flow and administers dialysate. Dialysate is a chemical bath that is used to draw waste products out of the blood.

Since the 1980s, the majority of hemodialysis treatments in the United States have been performed with hollow fiber dialyzers. A hollow fiber dialyzer is composed of thousands of tube-like hollow fiber strands encased in a clear plastic cylinder several inches in diameter. There are two compartments within the dialyzer (the blood compartment and the dialysate compartment).

The membrane that separates these two compartments is semipermeable. This means that it allows the passage of certain sized molecules across it, but prevents the passage of other, larger molecules. As blood

KEY TERMS

Access site— The vein tapped for vascular access in hemodialysis treatments. For patients with temporary treatment needs, access to the bloodstream is gained by inserting a catheter into the subclavian vein near the patient’s collarbone. Patients in long-term dialysis require stronger, more durable access sites, called fistulas or grafts, that are surgically created.

Dialysate— A chemical bath used in dialysis to draw fluids and toxins out of the bloodstream and supply electrolytes and other chemicals to the bloodstream.

Dialysis prescription— The general parameters of dialysis treatment that vary according to each patient’s individual needs. Treatment length, type of dialyzer and dialysate used, and rate of ultrafiltration are all part of the dialysis prescription.

Dialyzer— An artificial kidney usually composed of hollow fiber which is used in hemodialysis to eliminate waste products from the blood and remove excess fluids from the bloodstream.

Erythropoietin— A hormone produced by the kidneys that stimulates the production of red blood cells by bone marrow.

ESRD— End-stage renal disease; chronic or permanent kidney failure.

Extracorporeal circuit (ECC)— The path the hemodialysis patient’s blood takes outside of the body. It typically consists of plastic tubing, a hemodialysis machine, and a dialyzer.

Glomerulonephritis— A disease of the kidney that causes inflammation and scarring and impairs the kidney’s ability to filter waste products from the blood.

Hematocrit (Hct) level— A measure of red blood cells.

Glomerulonephritis— Kidney disease caused by scarring of the glomeruli, the small blood vessels in the nephrons, or filtering centers, of the kidneys.

Peritoneum— The abdominal cavity; the peritoneum acts as a blood filter in peritoneal dialysis.

is pushed through the blood compartment in one direction, suction or vacuum pressure pulls the dialysate through the dialysate compartment in a countercurrent, or opposite direction. These opposing pressures work to drain excess fluids out of the bloodstream and into the dialysate, a process called ultrafiltration.

A second process called diffusion moves waste products in the blood across the membrane and into the dialysate compartment, where they are carried out of the body. At the same time, electrolytes and other chemicals in the dialysate solution cross the membrane into the blood compartment. The purified, chemically balanced blood is then returned to the body.

Most hemodialysis patients require treatment three times a week, for an average of three to four hours per dialysis “run.” Specific treatment schedules depend on the type of dialyzer used and the patient’s current physical condition.

Blood pressure changes associated with hemodialysis may pose a risk for patients with heart problems. Peritoneal dialysis may be the preferred treatment option in these cases.

Peritoneal dialysis

In peritoneal dialysis, the patient’s peritoneum, or lining of the abdomen, acts as a blood filter. A catheter is surgically inserted into the patient’s abdomen. During treatment, the catheter is used to fill the abdominal cavity with dialysate. Waste products and excess fluids move from the patient’s bloodstream into the dialysate solution. After a waiting period of six to 24 hours, depending on the treatment method used, the waste-filled dialysate is drained from the abdomen and replaced with clean dialysate.

There are three types of peritoneal dialysis:

• Continuous ambulatory peritoneal dialysis (CAPD). CAPD is a continuous treatment that is self-administered and requires no machine. The patient inserts fresh dialysate solution into the abdominal cavity, waits four to six hours, and removes the used solution. The solution is immediately replaced with fresh dialysate. A bag attached to the catheter is worn under clothing.
• Continuous cyclic peritoneal dialysis (CCPD). Also called automated peritoneal dialysis (APD), CCPD is an overnight treatment that uses a machine to drain and refill the abdominal cavity, CCPD takes 10 to 12 hours per session.
• Intermittent peritoneal dialysis (IPD). This hospital-based treatment is performed several times a week. A machine administers and drains the dialysate solution, and sessions can take 12 to 24 hours.

Peritoneal dialysis is often the treatment option of choice in infants and children, whose small size can make vascular (through a vein) access difficult to maintain. Peritoneal dialysis can also be done outside of a clinical setting, which is more conducive to regular school attendance.

Peritoneal dialysis is not recommended for patients with abdominal adhesions or other abdominal defects, such as a hernia, that might compromise the efficiency of the treatment. It is also not recommended for patients who suffer frequent bouts of diverticulitis, an inflammation of small pouches in the intestinal tract.

Diagnosis/Preparation

Patients are weighed immediately before and after each hemodialysis treatment to evaluate their fluid retention. Blood pressure and temperature are taken and the patient is assessed for physical changes since their last dialysis run. Regular blood tests monitor chemical and waste levels in the blood. Prior to treatment, patients are typically administered a dose of heparin, an anticoagulant that prevents blood clotting, to ensure the free flow of blood through the dialyzer and an uninterrupted dialysis run for the patient.

Aftercare

Both hemodialysis and peritoneal dialysis patients need to be vigilant about keeping their access sites and catheters clean and infection-free during and between dialysis runs.

Dialysis is just one facet of a comprehensive treatment approach for ESRD. Although dialysis treatment is very effective in removing toxins and fluids from the body, there are several functions of the kidney it cannot mimic, such as regulating high blood pressure and red blood cell production. Patients with ESRD need to watch their dietary and fluid intake carefully and take medications as prescribed to manage their disease.

Risks

Many of the risks and side effects associated with dialysis are a combined result of both the treatment and the poor physical condition of the ESRD patient. Dialysis patients should always report side effects to their healthcare provider.

Anemia

Hematocrit (Hct) levels, a measure of red blood cells, are typically low in ESRD patients. This deficiency is caused by a lack of the hormone erythropoietin, which is normally produced by the kidneys. The problem is elevated in hemodialysis patients, who may incur blood loss during hemodialysis treatments. Epoetin alfa, or EPO (sold under the trade name Epogen), a hormone therapy, and intravenous or oral iron supplements are used to manage anemia in dialysis patients.

Cramps, nausea, vomiting, and headaches

Some hemodialysis patients experience cramps and flu-like symptoms during treatment. These can be caused by a number of factors, including the type of dialysate used, composition of the dialyzer membrane, water quality in the dialysis unit, and the ultrafiltration rate of the treatment. Adjustment of the dialysis prescription often helps alleviate many symptoms.

Hypotension

Because of the stress placed on the cardiovascular system with regular hemodialysis treatments, patients are at risk for hypotension, a sudden drop in blood pressure. This can often be controlled by medication and adjustment of the patient’s dialysis prescription.

Infection

Both hemodialysis and peritoneal dialysis patients are at risk for infection. Hemodialysis patients should keep their access sites clean and watch for signs of redness and warmth that could indicate infection. Peritoneal dialysis patients must follow the same precautions with their catheter. Peritonitis, an infection of the peritoneum, causes flu-like symptoms and can disrupt dialysis treatments if not caught early.

Infectious diseases

Because there is a great deal of blood exposure involved in dialysis treatment, a slight risk of contracting hepatitis B and hepatitis C exists. The hepatitis B vaccination is recommended for most hemodialysis patients. As of 2001, there has only been one documented case of HIV being transmitted in a United States dialysis unit to a staff member, and no documented cases of HIV ever being transmitted between dialysis patients in the United States. The strict standards of infection control practiced in modern hemodialysis units minimizes the chance of contracting one of these diseases.

Normal results

Because dialysis is an ongoing treatment process for many patients, a baseline for normalcy can be

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

The dialysis treatment prescription and regimen s usually overseen by a nephrologist (a doctor that pecializes in the kidney). The hemodialysis treatment itself is typically administered by a nurse or patient are technician in outpatient clinics known as dialysis enters, or in hospital-based dialysis units. In-home hemodialysis treatment is also an option for some patients, although access to this type of treatment may be limited by financial and lifestyle factors. An nvestment in equipment is required and another per-on in the household should be available for support and assistance with treatments. Peritoneal dialysis is also performed at home by the patient, perhaps with he aide of a home health-care worker.

difficult to gauge. Puffiness in the patient related to edema, or fluid retention, may be relieved after dialysis treatment. The patient’s overall sense of physical well being may also be improved.

Monthly blood tests to check the levels of urea, a waste product, help to determine the adequacy of the dialysis prescription. Another test, called Kt/V (dialyzer clearance multiplied by time of treatment and divided by the total volume of water in the patient’s body), is also performed to assess patient progress. A urea reduction ratio (URR) of 65% or higher, and a Kt/V of at least 1.2 are considered the benchmarks of dialysis adequacy by the Kidney Disease Outcomes Quality Initiative (K/ DOQI) of the National Kidney Foundation.

Morbidity and mortality rates

The USRDS reports that mortality rates for individuals on dialysis are also significantly higher than both kidney transplant patients and the general population, and expected remaining lifetimes of chronic dialysis patients are only one-fourth to one-fifth that of the general population. The hospitalization rates for people with ESRD are four times greater than that of the general population.

Alternatives

The only alternative to dialysis for ESRD patients is a successful kidney transplant. However, demand for donor kidneys has traditionally far exceeded supply. As of 2006, there were 70,000 patients on the United Network for Organ Sharing (UNOS) waiting

QUESTIONS TO ASK THE DOCTOR

• When and where will my dialysis treatments be scheduled?
• How should my diet change now that I’m on dialysis?
• What kind of vascular access will I get?
• Does my new dialysis center have a dialyzer reuse program? If so, what safety checks are in place to ensure I receive a properly treated dialyzer?
• What can I do to make dialysis more effective?
• Can you refer me to any ESRD patient support groups?
• Should I change my medication routine?

list for a kidney transplant. In 2005, about 16,000 patients received a kidney.

For patients with diabetes, the number one cause of chronic kidney failure in adults, the best way to avoid ESRD and subsequent dialysis is to maintain tight control of blood glucose levels through diet, exercise, and medication. Controlling high blood pressure is also important.

Resources

BOOKS

Brenner, B. M., et al. Brenner & Rector’s The Kidney. 7th ed. Philadelphia: Saunders, 2004.

Wein, A. J., et al. Campbell-Walsh Urology. 9th ed. Philadelphia: Saunders, 2007.

PERIODICALS

Eknoyan G., G. J. Beck, et al. “Effect of Dialysis Dose and Membrane Flux in Maintenance Hemodialysis.” New England Journal of Medicine 347 (December 19, 2002): 2010–2019.

ORGANIZATIONS

American Association of Kidney Patients. 3505 E. Frontage Rd., Suite 315, Tampa, FL 33607. (800) 749-2257. http://www.aakp.org.

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800) 638-8299. http://www.akfinc.org.

National Kidney Foundation. 30 East 33rd St., Suite 1100, New York, NY 10016. (800) 622-9010. http://www.kidney.org.

United States Renal Data System (USRDS), Coordinating Center. The University of Minnesota, 914 South 8th Street, Suite D-206, Minneapolis, MN 55404. 1-888-99USRDS. http://www.usrds.org.

Paula Anne Ford-Martin

Kidney dialysis

Definition

Dialysis treatment replaces the function of the kidneys, which normally serve as the body's natural filtration system. Through the use of a blood filter and a chemical solution known as dialysate, the treatment removes waste products and excess fluids from the bloodstream, while maintaining the proper chemical balance of the blood. There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Purpose

Dialysis is most commonly prescribed for patients with temporary or permanent kidney failure. People with end-stage renal disease (ESRD) have kidneys that are no longer capable of adequately removing fluids and wastes from their body or of maintaining the proper level of certain kidney-regulated chemicals in the bloodstream. For these individuals, dialysis is the only treatment option available outside of kidney transplantation . Dialysis may also be used to simulate kidney function in patients awaiting a transplant until a donor kidney becomes available. Also, dialysis may be used in the treatment of patients suffering from poisoning or overdose in order to quickly remove drugs from the bloodstream.

Demographics

As of December 31, 2000, in the United States, over 275,000 people were undergoing regular dialysis treatments to manage their ESRD. Diabetes mellitus is the leading single cause of ESRD. According to the 2002 Annual Data Report of the United States Renal Data System (USRDS), 42% of non-Hispanic dialysis patients in the United States have ESRD caused by diabetes. People of Native American and Hispanic descent are at an elevated high risk for both kidney disease and diabetes. ESRD caused by diabetes occurred in 65% of Hispanic dialysis patients. And of those Native Americans who had been on dialysis for one year in 1999, 82% had diabetes.

Hypertension (high blood pressure) is the second leading cause of ESRD in adults, accounting for 25.5% of the patient population, followed by glomerulonephritis (8.4%). African-Americans are more likely to develop hypertension-related ESRD than whites and Hispanics.

Among children and young adults under 20 on dialysis, glomerulonephritis is the leading cause of ESRD (31%), and hereditary, cystic, and congenital diseases account for 37%. Pediatric patients typically spend less time on dialysis than adults; according to the USRDS the average waiting period for a kidney transplant for patients under age 20 is 10 months, compared to the adult wait of approximately two years.

Description

There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Hemodialysis

Hemodialysis is the most frequently prescribed type of dialysis treatment in the United States. The treatment involves circulating the patient's blood outside of the body through an extracorporeal circuit (ECC), or dialysis circuit. Two needles are inserted into the patient's vein, or access site, and are attached to the ECC, which consists of plastic blood tubing, a filter known as a dialyzer (artificial kidney), and a dialysis machine that monitors and maintains blood flow and administers dialysate. Dialysate is a chemical bath that is used to draw waste products out of the blood.

Since the 1980s, the majority of hemodialysis treatments in the United States have been performed with hollow fiber dialyzers. A hollow fiber dialyzer is composed of thousands of tube-like hollow fiber strands encased in a clear plastic cylinder several inches in diameter. There are two compartments within the dialyzer (the blood compartment and the dialysate compartment).

The membrane that separates these two compartments is semipermeable. This means that it allows the passage of certain sized molecules across it, but prevents the passage of other, larger molecules. As blood is pushed through the blood compartment in one direction, suction or vacuum pressure pulls the dialysate through the dialysate compartment in a countercurrent, or opposite direction. These opposing pressures work to drain excess fluids out of the bloodstream and into the dialysate, a process called ultrafiltration.

A second process called diffusion moves waste products in the blood across the membrane and into the dialysate compartment, where they are carried out of the body. At the same time, electrolytes and other chemicals in the dialysate solution cross the membrane into the blood compartment. The purified, chemically balanced blood is then returned to the body.

Most hemodialysis patients require treatment three times a week, for an average of three to four hours per dialysis "run." Specific treatment schedules depend on the type of dialyzer used and the patient's current physical condition.

Blood pressure changes associated with hemodialysis may pose a risk for patients with heart problems. Peritoneal dialysis may be the preferred treatment option in these cases.

Peritoneal dialysis

In peritoneal dialysis, the patient's peritoneum, or lining of the abdomen, acts as a blood filter. A catheter is surgically inserted into the patient's abdomen. During treatment, the catheter is used to fill the abdominal cavity with dialysate. Waste products and excess fluids move from the patient's bloodstream into the dialysate solution. After a waiting period of six to 24 hours, depending on the treatment method used, the waste-filled dialysate is drained from the abdomen and replaced with clean dialysate.

There are three types of peritoneal dialysis:

• Continuous ambulatory peritoneal dialysis (CAPD). CAPD is a continuous treatment that is self-administered and requires no machine. The patient inserts fresh dialysate solution into the abdominal cavity, waits four to six hours, and removes the used solution. The solution is immediately replaced with fresh dialysate. A bag attached to the catheter is worn under clothing.
• Continuous cyclic peritoneal dialysis (CCPD). Also called automated peritoneal dialysis (APD), CCPD is an overnight treatment that uses a machine to drain and refill the abdominal cavity, CCPD takes 10 to 12 hours per session.
• Intermittent peritoneal dialysis (IPD). This hospital-based treatment is performed several times a week. A machine administers and drains the dialysate solution, and sessions can take 12 to 24 hours.

Peritoneal dialysis is often the treatment option of choice in infants and children, whose small size can make vascular (through a vein) access difficult to maintain. Peritoneal dialysis can also be done outside of a clinical setting, which is more conducive to regular school attendance.

Peritoneal dialysis is not recommended for patients with abdominal adhesions or other abdominal defects, such as a hernia, that might compromise the efficiency of the treatment. It is also not recommended for patients who suffer frequent bouts of diverticulitis, an inflammation of small pouches in the intestinal tract.

Diagnosis/Preparation

Patients are weighed immediately before and after each hemodialysis treatment to evaluate their fluid retention. Blood pressure and temperature are taken and the patient is assessed for physical changes since their last dialysis run. Regular blood tests monitor chemical and waste levels in the blood. Prior to treatment, patients are typically administered a dose of heparin, an anticoagulant that prevents blood clotting, to ensure the free flow of blood through the dialyzer and an uninterrupted dialysis run for the patient.

Aftercare

Both hemodialysis and peritoneal dialysis patients need to be vigilant about keeping their access sites and catheters clean and infection-free during and between dialysis runs.

Dialysis is just one facet of a comprehensive treatment approach for ESRD. Although dialysis treatment is very effective in removing toxins and fluids from the body, there are several functions of the kidney it cannot mimic, such as regulating high blood pressure and red blood cell production. Patients with ESRD need to watch their dietary and fluid intake carefully and take medications as prescribed to manage their disease.

Risks

Many of the risks and side effects associated with dialysis are a combined result of both the treatment and the poor physical condition of the ESRD patient. Dialysis patients should always report side effects to their healthcare provider.

Anemia

Hematocrit (Hct) levels, a measure of red blood cells, are typically low in ESRD patients. This deficiency is caused by a lack of the hormone erythropoietin, which is normally produced by the kidneys. The problem is elevated in hemodialysis patients, who may incur blood loss during hemodialysis treatments. Epoetin alfa, or EPO (sold under the trade name Epogen), a hormone therapy, and intravenous or oral iron supplements are used to manage anemia in dialysis patients.

Cramps, nausea, vomiting, and headaches

Some hemodialysis patients experience cramps and flu-like symptoms during treatment. These can be caused by a number of factors, including the type of dialysate used, composition of the dialyzer membrane, water quality in the dialysis unit, and the ultrafiltration rate of the treatment. Adjustment of the dialysis prescription often helps alleviate many symptoms.

Hypotension

Because of the stress placed on the cardiovascular system with regular hemodialysis treatments, patients are at risk for hypotension, a sudden drop in blood pressure. This can often be controlled by medication and adjustment of the patient's dialysis prescription.

Infection

Both hemodialysis and peritoneal dialysis patients are at risk for infection. Hemodialysis patients should keep their access sites clean and watch for signs of redness and warmth that could indicate infection. Peritoneal dialysis patients must follow the same precautions with their catheter. Peritonitis, an infection of the peritoneum, causes flu-like symptoms and can disrupt dialysis treatments if not caught early.

Infectious diseases

Because there is a great deal of blood exposure involved in dialysis treatment, a slight risk of contracting hepatitis B and hepatitis C exists. The hepatitis B vaccination is recommended for most hemodialysis patients. As of 2001, there has only been one documented case of HIV being transmitted in a United States dialysis unit to a staff member, and no documented cases of HIV ever being transmitted between dialysis patients in the United States. The strict standards of infection control practiced in modern hemodialysis units minimizes the chance of contracting one of these diseases.

Normal results

Because dialysis is an ongoing treatment process for many patients, a baseline for normalcy can be difficult to gauge. Puffiness in the patient related to edema, or fluid retention, may be relieved after dialysis treatment. The patient's overall sense of physical well being may also be improved.

Monthly blood tests to check the levels of urea, a waste product, help to determine the adequacy of the dialysis prescription. Another test, called Kt/V (dialyzer clearance multiplied by time of treatment and divided by the total volume of water in the patient's body), is also performed to assess patient progress. A urea reduction ratio (URR) of 65% or higher, and a Kt/V of at least 1.2 are considered the benchmarks of dialysis adequacy by the Kidney Disease Outcomes Quality Initiative (K/DOQI) of the National Kidney Foundation.

Morbidity and mortality rates

The USRDS reports that mortality rates for individuals on dialysis are also significantly higher than both kidney transplant patients and the general population, and expected remaining lifetimes of chronic dialysis patients are only one-fourth to one-fifth that of the general population. The hospitalization rates for people with ESRD are four times greater than that of the general population.

Alternatives

The only alternative to dialysis for ESRD patients is a successful kidney transplant. However, demand for donor kidneys has traditionally far exceeded supply. As of March 1, 2003, there were 53,619 patients on the United Network for Organ Sharing (UNOS) waiting list for a kidney transplant, with an additional 2,405 waiting for a combination kidney and pancreas transplant. In the entire year of 2001, only 14,095 donors gave kidneys, according to UNOS.

For patients with diabetes, the number one cause of chronic kidney failure in adults, the best way to avoid ESRD and subsequent dialysis is to maintain tight control of blood glucose levels through diet, exercise , and medication. Controlling high blood pressure is also important.

Resources

books

Cameron, J. S. Kidney Failure: The Facts. New York: Oxford University Press, 1999.

National Kidney Foundation. Dialysis Outcomes Quality Initiatives (NOQI). Vol. 1-5. New York: National Kidney Foundation, 1997.

U.S. Renal Data System. USRDS 2002 Annual Data Report: Atlas of End-Stage Renal Disease in the United States. Bethesda, MD: The National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, 2002.

periodicals

Eknoyan G., G. J. Beck, et al. "Effect of Dialysis Dose and Membrane Flux in Maintenance Hemodialysis." New England Journal of Medicine 347 (December 19, 2002): 2010–2019.

organizations

American Association of Kidney Patients. 3505 E. Frontage Rd., Suite 315, Tampa, FL 33607. (800) 749-2257. <http://www.aakp.org>.

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800) 638-8299. <http://www.akfinc.org>.

National Kidney Foundation. 30 East 33rd St., Suite 1100, New York, NY 10016. (800) 622-9010. <http://www.kidney.org>.

United States Renal Data System (USRDS), Coordinating Center. The University of Minnesota, 914 South 8th Street, Suite D-206, Minneapolis, MN 55404. 1-888-99USRDS. <http://www.usrds.org>.

Paula Anne Ford-Martin

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

The dialysis treatment prescription and regimen is usually overseen by a nephrologist (a doctor that specializes in the kidney). The hemodialysis treatment itself is typically administered by a nurse or patient care technician in outpatient clinics known as dialysis centers, or in hospital-based dialysis units. In-home hemodialysis treatment is also an option for some patients, although access to this type of treatment may be limited by financial and lifestyle factors. An investment in equipment is required and another person in the household should be available for support and assistance with treatments. Peritoneal dialysis is also performed at home by the patient, perhaps with the aide of a home health-care worker.

QUESTIONS TO ASK THE DOCTOR

• When and where will my dialysis treatments be scheduled?
• How should my diet change now that I'm on dialysis?
• What kind of vascular access will I get?
• Does my new dialysis center have a dialyzer reuse program? If so, what safety checks are in place to ensure I receive a properly treated dialyzer?
• What can I do to make dialysis more effective?
• Can you refer me to any ESRD patient support groups?
• Should I change my medication routine?

Dialysis, kidney

Definition

Dialysis treatment replaces the function of the kidneys , which normally serve as the body's natural filtration system. Through the use of a blood filter and a chemical solution known as dialysate, dialysis removes waste products and excess fluids from the bloodstream, while maintaining the proper chemical balance of the blood. There are two types of dialysis treatment: hemodialysis and peritoneal dialysis .

Purpose

Dialysis also can be used to remove overdosed drugs or poisons from the bloodstream more quickly than normally functioning kidneys. Its most prevalent application, however, is for patients with temporary or permanent kidney failure. For patients with end-stage renal disease (ESRD), dialysis is the only renal replacement

therapy available other than kidney transplantation. In the United States, nearly 250,000 patients receive regular dialysis treatments to manage ESRD.

Precautions

Blood pressure changes during hemodialysis may pose a risk for patients with heart disease. Peritoneal dialysis may be the preferred treatment option for these patients. Peritoneal dialysis is not recommended for patients with abdominal adhesions or other abdominal defects, such as a hernia, which might compromise the efficiency of the treatment. It is also not recommended for patients who suffer frequent bouts of diverticulitis (inflammation of diverticuli, small pouches in the colon).

Description

There are two types of dialysis treatment: hemodialysis and peritoneal dialysis.

Hemodialysis

Hemodialysis is the most frequently prescribed type of dialysis in the United States. The treatment involves circulating the patient's blood outside of the body through an extracorporeal circuit (ECC), or dialysis circuit. Two needles are inserted into the patient's vein, or access site, and are attached to the ECC, which consists of plastic blood tubing, a filter known as a dialyzer (artificial kidney), and a dialysis machine that monitors and maintains blood flow and administers dialysate. Dialysate is a chemical bath that is used to draw waste products out of the blood.

Since the 1980s, the majority of hemodialysis treatments in the United States have been performed with hollow fiber dialyzers. A hollow fiber dialyzer is composed of thousands of tube-like hollow fiber strands encased in a clear plastic cylinder several inches in diameter. There are two compartments within the dialyzer (the blood compartment and the dialysate compartment). The membrane that separates these two compartments is semipermeable; it allows the passage of certain sized molecules across it, but prevents the passage of other, larger molecules. As blood is pushed through the blood compartment in one direction, suction or vacuum pressure pulls the dialysate through the dialysate compartment in a counter-current, or opposite direction. These opposing pressures work to drain excess fluids out of the bloodstream and into the dialysate, a process called ultrafiltration.

A second process, called diffusion, moves waste products in the blood across the membrane into the dialysate compartment, where they are carried out of the body. At the same time, electrolytes and other chemicals in the dialysate solution cross the membrane into the blood compartment. The purified, chemically balanced blood is then returned to the body.

Most hemodialysis patients require treatment three times a week, for an average of three to four hours per dialysis "run." Specific treatment schedules depend on the type of dialyzer used and the patient's current physical condition. While the treatment prescription and regimen is usually overseen by a nephrologist (a doctor that specializes in the kidney), dialysis treatments are typically administered by a nurse or dialysis technician in out-patient clinics known as dialysis centers or in hospital-based dialysis units. In-home hemodialysis treatment is also an option for some patients, although access to this type of treatment may be limited by financial and lifestyle factors. An investment in equipment is required and another person in the household should be available for support and assistance with treatments.

Peritoneal dialysis

In peritoneal dialysis, the patient's peritoneum (lining of the abdomen) acts as a blood filter. A catheter is surgically inserted into the patient's abdomen. During treatment, the catheter is used to fill the abdominal cavity with dialysate. Waste products and excess fluids move from the patient's bloodstream into the dialysate solution. After a waiting period of six to 24 hours, depending on the treatment method used, the waste-filled dialysate is drained from the abdomen and replaced with clean dialysate.

There are three types of peritoneal dialysis:

• Continuous ambulatory peritoneal dialysis (CAPD). This treatment is self-administered and requires no machine. The patient inserts fresh dialysate solution into the abdominal cavity, waits four to six hours, and removes the used solution. The solution is immediately replaced with fresh dialysate. A bag attached to the catheter is worn under clothing.
• Continuous cyclic peritoneal dialysis (CCPD). An overnight treatment that uses a machine to drain and refill the abdominal cavity, CCPD takes 10–12 hours per session.
• Intermittent peritoneal dialysis (IPD). This hospital-based treatment is performed several times a week. A machine administers and drains the dialysate solution, and sessions can take up to 24 hours.

Peritoneal dialysis is often the treatment option of choice for infants and children, whose small size can make vascular access difficult to maintain. Peritoneal dialysis also may be performed outside of a clinical setting, which is more conducive to regular school attendance.

Preparation

A dialysis technologist, nurse, or nursing assistant weighs patients immediately before and after each hemodialysis treatment to assess their fluid balance . The dialysis technologist, nurse, or nursing assistant also measures and records blood pressure and temperature and assesses patients for any physical changes since their last dialysis run. Regular blood tests, performed by laboratory technologists, monitor chemical and waste levels in the blood. Prior to treatment, patients are typically administered a dose of heparin (an anticoagulant that prevents blood clotting) to ensure the free flow of blood through the dialyzer and an uninterrupted dialysis run.

Aftercare

Both hemodialysis and peritoneal dialysis patients must be vigilant about keeping their access sites and catheters clean and infection-free during and between dialysis runs.

Dialysis is just one facet of a comprehensive treatment approach for ESRD. Although dialysis treatment is very effective in removing toxins and fluids from the body, there are several functions of the kidney it cannot mimic, such as regulating high blood pressure and red blood cell production. Patients with ESRD need to watch their diet and fluid intake carefully and adhere to prescribed medications to effectively manage their disease.

Complications

Many of the risks and side effects associated with dialysis are a combined result of both the treatment and the poor physical condition of the ESRD patient. Dialysis patients should be instructed to report side effects to their healthcare provider.

Anemia

Hematocrit (Hct) levels, the percentage of whole blood comprised of red blood cells, are typically low in ESRD patients. This deficiency is caused by a lack of the hormone erythropoietin, which is normally produced by the kidneys. The problem is exacerbated in hemodialysis patients, who may incur blood loss during hemodialysis

KEY TERMS

Access site —The vein tapped for vascular access in hemodialysis treatments. For patients with temporary treatment needs, access to the bloodstream is gained by inserting a catheter into the subclavian vein. Patients in long-term dialysis require stronger, more durable access sites, called fistulas or grafts, that are surgically-created.

Dialysate —A chemical bath used in dialysis to draw fluids and toxins out of the bloodstream and supply electrolytes and other chemicals to the bloodstream.

Dialysis prescription —The general parameters of dialysis treatment that vary according to each patient's individual needs. Treatment length, type of dialyzer and dialysate used, and rate of ultrafiltration are all part of the dialysis prescription.

Dialyzer —An artificial kidney usually composed of hollow fiber that is used in hemodialysis to eliminate waste products from the blood and remove excess fluids from the bloodstream.

Erythropoietin —A hormone produced by the kidneys that stimulates the production of red blood cells by bone marrow.

ESRD —End-stage renal disease; chronic or permanent kidney failure.

Extracorporeal circuit (ECC) —The path the hemodialysis patient's blood takes outside of the body. It typically consists of plastic tubing, a hemodialysis machine, and a dialyzer.

Hematocrit (Hct) level —A measure of red blood cells.

Peritoneum —The abdominal cavity; the peritoneum acts as a blood filter in peritoneal dialysis.

treatments. Epoetin alfa, a hormone therapy also known as EPO (sold under the trade name Epogen), and intravenous or oral iron supplements are used to manage anemia in dialysis patients.

Cramps, nausea, vomiting, and headaches

Some hemodialysis patients experience cramps and flu-like symptoms during treatment. These may be caused by a number of factors, including the type of dialysate used, composition of the dialyzer membrane, water quality in the dialysis unit, and the ultrafiltration rate of the treatment. Adjustment of the dialysis prescription often helps alleviate symptoms.

Hypotension

Because of the stress placed on the cardiovascular system with regular hemodialysis treatments, patients are at risk for hypotension, a sudden drop in blood pressure. This can often be controlled by medication and adjustment of the patients' dialysis prescription.

Infection

Both hemodialysis and peritoneal dialysis patients are at risk for infection . Hemodialysis patients should keep their access sites clean and watch for signs of redness and warmth that could indicate infection. Peritoneal dialysis patients must follow the same precautions with their catheters in order to prevent peritonitis. Peritonitis, an infection of the peritoneum, causes flu-like symptoms and can disrupt dialysis treatments if not detected promptly.

Infectious diseases

Because there is a great deal of blood exposure involved in dialysis treatment, a slight risk of contracting hepatitis B and hepatitis C exists. The hepatitis B vaccination is recommended for most hemodialysis patients. As of 1997, there has only been one documented case of HIV being transmitted in a United States dialysis unit to a staff member, and no documented cases of HIV ever being transmitted between dialysis patients in the United States. The strict standards of infection control practiced in modern hemodialysis units makes the chance of contracting one of these diseases very small.

Results

Fluid retention may be relieved after dialysis treatment. The patient's overall sense of physical well being may also be improved. Because dialysis is an ongoing treatment process for many patients, a baseline for normalcy can be difficult to gauge.

Health care team roles

Patients receiving dialysis treatments are cared for by a team that includes nephrologists, dialysis technicians, nurses, radiology technicians, and laboratory technicians. Registered dietitians, nutritionists, and nurses instruct patients about dietary changes to manage their disease.

Resources

BOOKS

Cameron, J. S. Kidney Failure: The Facts. New York, NY: Oxford Univ. Press, 1996.

The Washington Manual of Medical Therapeutics. 30th ed. Philadelphia: Lippincott Williams & Wilkins, 2001.

ORGANIZATIONS

American Association of Kidney Patients (AAKP). 100 S. Ashley Drive, Suite 280, Tampa, FL 33602. (800)749-2257. <http://www.aakp.org>.

American Kidney Fund (AKF). Suite 1010, 6110 Executive Boulevard, Rockville, MD 20852. (800)638-8299. <http://www.arbon.com/kidney>.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Natcher Building, 6AS-13K, 45 Center Drive, Bethesda, MD 20892-6600. <http://www.niddk.nih.gov>.

National Kidney Foundation (NKF). 30 East 33rd Street, New York, NY 10016. (800)622-9020. <http://www.kidney.org>.

United States Renal Data System (USRDS). USRDS Coordinating Center, 315 W. Huron, Suite 240, Ann Arbor, MI 48103. (313)998-6611. <http://www.med.umich.edu/usrds>.

Barbara Wexler