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Gerontologizing Nephrology

1999; American Society of Nephrology; Volume: 10; Issue: 8 Linguagem: Inglês

10.1681/asn.v1081824

1533-3450

Robert Luke, Laurence H. Beck,

Aging, Health, and Disability

The American Geriatrics Society has been sponsoring a series of geriatric educational retreats by the John A. Hartford Foundation. The goal of these retreats is to integrate geriatrics into the subspecialties of internal medicine. The basic belief of the sponsors is that the art and science of geriatrics is best utilized when these skills are integrated into all aspects of the care of the elderly by both primary care and subspecialty physicians rather than by an approach emphasizing referral of “geriatric problems” to subspecialist geriatricians. Geriatrics, in this construct, remains an academic, teaching, research, and tertiary referral discipline. Many geriatric patients are seen by general internists and by the subspecialists of internal medicine. Thus, knowledge of the essentials of geriatrics is essential to the optimum practice of all internists. This past summer a conference including some of the leaders of the disciplines of geriatrics and nephrology was held in Jasper, Alberta, Canada. The goals of the conference were to develop strategies to enhance the training of subspecialty fellows with skills in geriatric medicine, to focus the interest of academic and teaching subspecialists on research in prevalent geriatric problems, and to develop knowledge of geriatrics within nephrology. We also hoped to develop a draft curriculum and to attempt to ensure that the appropriate licensing exams included relevant geriatric content. Those attending represented the leadership of the American Society of Nephrology, the Renal Physicians Association, the National Kidney Foundation, and the American Geriatrics Society. Also included were nephrologists active in the American Board of Internal Medicine and the Nephrology Residency Review Committee. The purpose of this report is to describe the major conclusions and outcomes of this conference. The average age of patients starting dialysis for end-stage renal disease (ESRD) in the United States is 62 yr and continues to increase. Twenty percent of all treated ESRD patients in this country are over the age of 75, and about 50% of all patients on hemodialysis are over the age of 65. The prevalence of the major diseases causing ESRD—hypertension and diabetes mellitus—increases substantially with aging; likewise, the annual incidence rates of new ESRD are highest in the age group 65 to 74 yr at approximately one per thousand. Because of the increase in older patients in our population, including minorities with an even higher prevalence of renal disease, a growing number of elderly patients will require renal replacement therapy. Nephrologists will increasingly require a working knowledge of geriatrics. Approximately three million Americans are now over the age of 85, and this group will increase to 10 to 50 million by the year 2050. Nursing home beds are estimated to increase from 1.5 million in 1993 to 5 million in 2040. At the same time, acute beds will fall from 1 million to 500,000. The percentage of health care expenditures in the United States going to those over 65 is likely to move from its current 38% to 75% by the year 2030. The annual incidence of ESRD is still increasing by 6 to 7% annually, and estimates of the number of U.S. patients on dialysis in the year 2010 are in the range 600,000 to 800,000. The pressure of changing demographics is thus overwhelming, and our educational, research, and service efforts in nephrology must reflect these changes. Nephrologists attending the meeting learned much from the geriatricians' presentations in addition to the striking demographic changes that we face. Like those of nephrologists, the patients of geriatricians are extremely complex with involvement of multiple organ systems. However, geriatricians focus on a functional approach, especially when addressing the realities and demands of daily living in the frail elderly with multisystem disease problems. A National Institutes of Health consensus conference found that “comprehensive geriatric assessment is a multidisciplinary evaluation in which the multiple problems of older persons are uncovered, described, and explained, if possible, and in which sources and strengths of the person are catalogued, need for services assessed, and a coordinated care plan developed to focus intervention on the person's problem.” The domains of assessment are medical (e.g., gait, vision, hearing); functional (e.g., activities of daily living); psychologic (e.g., cognition and affect); and social (e.g., financial security, support network, advance directives.) Quality of life issues are usually of higher value than cure of disease. Geriatricians observed that nephrology had developed a system giving a continuum of care to patients with ESRD undergoing renal replacement therapy and that this system could be a model of geriatric care for elderly patients with complex problems. Nephrologists work with a team of providers that includes trained mid-level practitioners, and employ multidisciplinary data collection and focused care plans. Geriatricians' assessment techniques are in general applied to patients who, from the managed care viewpoint, are “outliers,” just like ESRD patients. Geriatricians, like nephrologists caring for patients with chronic renal failure, continually search for acute-on-chronic disease; even when the underlying progressive organ disease cannot be cured, exacerbating factors can be identified and dealt with to return the patient to his or her previous status. Both disciplines believe that current professional manpower shortages may become worse over the next decade both because of lack of entry of residents into training in our subspecialties and from increasing numbers of patients. Optimum care demands an interdisciplinary team approach in which the primary care physician in the earlier stages of disease is the leader, with the geriatrician or nephrologist becoming the leader as more complex disease interactions develop. Both disciplines also believe that we must begin to help focus primary care efforts in the prevention or at least postponement of irreversible organ failure. Many of these preventive measures are now established and include good nutrition, exercise, treatment of hypertension, hyperlipidemia, diabetes (the incidence of renal complications is similar in both type I and type II), obesity, and cessation of smoking. Involvement of a geriatrician in teams involved in selecting and preparing patients for ESRD care, as well as in a consultant capacity for the complications of dialysis and transplantation most relevant to gerontology, would be beneficial to our discipline. Some of our patients are already in nursing homes, and the percentage of patients requiring renal replacement therapy in such environments (including day care for the elderly) is likely to increase. As we move into increasing requirements for capitated care for patients with ESRD, geriatricians could provide invaluable assistance in selection for dialysis and in end-of-life issues. Nephrologists must be competent pharmacologists because of the importance of the renal route of excretion of many drugs, because all renal syndromes can be produced by medications and because our patients require numerous drugs for optimum therapy. Insight was provided into the dangers of multiple medications especially in the elderly. Compliance with therapy falls off rapidly and adverse side effects increase exponentially once more than five different medications are being taken. About one in four patients taking more than 10 medications per day will have an adverse drug reaction; ESRD patients take a median of 8 to 10 prescription drugs. Epidemiologic and surveillance data demonstrate that drug therapy, in addition to offering improvement in quality and quantity of life, is also a major source of morbidity and mortality for the aged, and especially for the aged renal, patient. We in nephrology must address the complex multiple-drug, multiple-dose regimens we expect our patients to follow both before and after the onset of ESRD. Examples of important pathophysiologic changes relevant to drug therapy in the elderly are decrease in local endothelial nitric oxide formation, impairment of β-adrenoreceptor function, and diminished baroreceptor reflex sensitivity. The latter is associated with a high prevalence of orthostasis, both symptomatic and asymptomatic. The elderly are particularly susceptible to the renal side effects of nonsteroidal antiinflammatory drugs, including acute renal failure, hyperkalemia associated with hyporeninemic hypoaldosteronism, aminoglycoside-induced nephrotoxicity, and analgesic-associated nephropathy. It is still not clear whether nonsteroidal anti-inflammatory drugs, taken alone, can lead to chronic renal failure. Renal problems and diseases especially relevant to the geriatric age group include rapidly progressive glomerulonephritis, analgesic nephropathy, renovascular renal failure, dysregulation of osmolality, and the interaction between osteoporosis and renal osteodystrophy. An elevated serum creatinine and/or proteinuria are very important risk factors for cardiovascular disease; not enough attention is paid to these in the primary care of the elderly. A “normal” serum creatinine, especially in the frail elderly with diminished muscle mass, is compatible with a significantly impaired GFR. Indeed, the Cockroft—Gault formula for creatinine clearance is not well authenticated beyond the age of 70 yr. We therefore need better measures of renal excretory, metabolic, and synthetic function. It is now well documented that systolic hypertension (including the isolated type) is a strong risk factor for cardiovascular events in the elderly; antihypertensive treatment is highly efficacious in prevention of these, and it is likely, but not yet proven, to be effective also in postponing primary hypertensive ESRD. Just as the number of lives requiring treatment to prevent a cardiovascular event is much smaller in the elderly, because of the greater incidence of these events, the same is likely to be true of cardiovascular events in dialysis patients. That is, greater and earlier benefits from proven interventions would be anticipated in dialysis patients, whose cardiovascular risk is increased at least 30 times over that of the normal age-matched population. This statement is likely to be true also for the approximately two million patients in the U.S. population not on dialysis, with chronic renal failure and serum creatinines greater than 3 mg/dl. Geriatricians have dealt with measuring the burden of disease and quality of life issues in the elderly for some time, but nephrologists are only beginning to tackle these areas, which are especially important in the elderly patient on dialysis. Comorbidity in such patients increases with age; over the age of 70 there are, on average, five comorbid conditions compared with 2.5 in those under 70. Nevertheless, ESRD at age 75 confers a relative risk of death of just under 3, compared with the nonrenal population, whereas at age 45 the relative risk is 20. We are, however, beginning to look at measures other than mortality in ESRD treatment. Morbidity can be measured by the index of coexisting diseases to account for comorbidity in comparing different treatments, such as hemodialysis and peritoneal dialysis; quality of life by the SF-36 health survey; and better measures of patient preference, such as time trade-offs, are available. Managed care is currently struggling to deal with the ill Medicare population; it is likely that similar problems will prevail in applying managed care, especially total capitation, to patients with ESRD. An informal survey of the corporate medical directors of nationwide health plans providing services to the senior population revealed surprisingly little interest or concern for renal disease. When rank-ordered, nephrology was at the bottom both for the provision of clinical services and for professional costs. In disease management, virtually no major health plans focused on any measure of nephropathy. Nephrology has done too little thus far to define its role in managed care and prevention, especially with the geriatric population. In contrast to the lack of interest in disease management for chronic renal disease, much is now being done for patients with diabetes mellitus. The use of expensive, life-prolonging technology raises increasingly tough ethical issues in a capitated payment system, especially in the selection of patients for renal replacement therapy and the potential pressures for withdrawal of often elderly complex patients from dialysis. Withdrawal of dialysis is now the major cause of death in ESRD patients over the age of 70; even in younger patients it is now the second most common cause after cardiovascular diseases. About 50% of patients die within 8 days of cessation of dialysis; hospice treatment may be appropriate. Withdrawal from dialysis is more common in the elderly, but a striking exception occurs in Japan where withdrawal from dialysis falls with age. A related problem is that, in 20% of patients who have become mentally incompetent, the relatives wish to continue dialysis in what most nephrologists would consider a futile therapeutic effort. Ten percent of patients waiting for cadaveric kidney transplants are over the age of 65. Survival after transplant in the elderly is, as in all adult age groups, better than for patients on dialysis. Rehabilitative efforts after transplantation in the elderly must be vigorous for maximum benefit from the procedure. The concept of a “senior citizen panel” for the utilization of cadaveric kidneys from older donors—up to 80 yr of age—is being explored. Grandparent donation is likely to increase. Support was expressed for a “liberal start and stop policy” including a 30-d “trial of dialysis” in elderly patients with substantial comorbidity. There was a strong feeling that there would be a need for an independent ombudsman to oversee patient rights in this area. Obviously, we must redouble our efforts to obtain effective advance directives for all dialysis patients, only 20% of whom have completed these. The new program requirements for nephrology fellowship education in internal medicine, to be implemented in July 1999, state that adequate in-patient and ambulatory experience must include the geriatric age group and emphasize that there must be sufficient numbers of patients over the age of 70 included in training. The renal training program director's committee is working with the American Geriatrics Society to develop a core curriculum that nephrology training program directors can then incorporate as they wish into a formalized nephrology curriculum. Support was given to the idea of a combined Nephrology—Geriatric 3-yr fellowship, perhaps supported by the Hartford Foundation. A review of American Board of Internal Medicine-Nephrology questions showed that 14% of the questions related to patients over 65 and 8% to patients over 75. This will be monitored closely to ensure that this examination reflects the demographics of the population cared for by nephrologists. The next American Society of Nephrology meeting, under the chairmanship of Dr. William Bennett, will include a strong geriatric nephrology component in both the clinical and research arenas. Representatives of the National Institute for Aging (NIA) and of the kidney program within the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) were present. At present, the NIA has virtually no research grants in renal disease. For the growing geriatric population over the age of 75, there is a dearth of information on the effects of pharmacologic agents and concerns about the applicability of findings from younger patients in clinical trials. Important prospective drug and clinical trials have excluded such patients, even in studies aimed at “the elderly,” such as in recent antihypertensive trials. It was suggested that the NIA and the Kidney Program could issue a joint request for applications for study of the pathophysiology of the aging kidney. More research is needed into the interaction among diabetes mellitus, hypertensive vascular changes, and atherosclerosis of the renal vessels with genetic susceptibility to renal damage from these processes and from the effects of aging in general. Although it is widely believed that renal function routinely falls with age, almost one-third of patients in the Baltimore Longitudinal Study of Aging did not show a fall in GFR. The processes of glomerulosclerosis and fibrogenesis, especially tubulointerstitial changes in the aging kidney, are important and likely contribute to the rising incidence of ESRD in the elderly. The role of the immunologic incompetence of aging in the increased prevalence of rapidly progressive glomerulonephritis and vasculitis in the elderly requires further elucidation. In the clinical arena, the science of nephrology was compared to that of cardiology before the determination of relevant risk factors for cardiovascular disease in the Framingham study. It was concluded that more prospective studies of cohorts of patients both for chronic renal failure and for patients receiving renal replacement therapy are needed. This is especially true for cardiovascular risk factors in these patients because this remains the major cause of mortality and morbidity. It was suggested that the time has come for a Joint National Commission for the prevention of renal disease akin to that which has been so successful in cardiovascular disease. The National Institutes of Health, the Agency for Health Care Policy and Research, the Health Care Financing Administration, the Veterans Administration, and the pharmaceutical industry should all cooperate as with the major professional societies in this effort. Cross-sectional studies with disease registries were also suggested, especially for acute renal failure, the prevalence of which and the mortality from which substantially increase in the elderly. The above agencies should also cooperate more in attempting to establish clinical trials for possible preventive measures, such as antihyperlipidemic therapy, for chronic renal failure. In summary, it is concluded that our discipline is underutilizing the skills and knowledge of geriatrics, even though the percentage of our ESRD patients over 75 yr of age is increasing steadily. A new geriatric curriculum for nephrology training is being prepared, and the number of questions relating to elderly renal patients will increase on the Nephrology Boards. Geriatric clinical approaches, which emphasize function, should be incorporated into the selection and care of elderly ESRD patients. We must address the polypharmacy and multiple drug dosing in our patients. We should engage the managed care industry in discussions concerning appropriate disease management and prevention for chronic renal failure and ESRD. In the area of clinical research, we can use better methods to measure comorbidity, quality of life, and patient preferences. Clinical trials should stop excluding patients over age 75, especially for trials involving relevant medications. Research in the structure and function of the aging kidney and the interactions with hypertension and diabetes is deficient; we urge consideration of a joint request for applications to be issued by the Institute of Aging and the Kidney Program/NIDDK to expand research in these areas. We support strongly the establishment of a Joint National Committee—akin to that for hypertension—to encourage prevention of progressive renal disease. Acknowledgments The conference was supported by the John A. Hartford Foundation. The leader of the project is Dr. William Hazzard, who provided inspirational leadership. The contributors to the conference included: Darrell Abernathy, M.D. Christine Abrass, M.D. Itamar Abrass, M.D. Laurence Beck, M.D. William Bennett, M.D. Tomas Berl, M.D. Margaret Bia, M.D. Craig Brater, M.D. Wendy Brown, M.D. Vardaman Buckalew, M.D. James Childress, M.D. Richard Glassock, M.D. William Henrich, M.D. Keith Hruska, M.D. David Humes, M.D. Carl Kjellstrand, M.D. Saulo Klahr, M.D. Juha Kokko, M.D. Joel Kopple, M.D. Andrew Levy, M.D. Julia Lewis, M.D. Paul McGann, M.D. Dimitrios G. Oreopoulos, M.D. Joseph Ouslander, M.D. Robert Schwartz, M.D. David Staskin, M.D. Richard Toto, M.D. Martin White, M.D. James Winchester, M.D. We are also most grateful to Nancy Woolard for all of her arrangements.