falla renal cronica estadio IV

The Clinical Problem

Chronic kidney disease is characterized by a progressive decline in the GFR; the diagnosis is made on the basis of a reduced GFR for a minimum of 3 months, often accompanied by albuminuria. The Kidney Disease Outcomes Quality Initiative of the National Kidney Foundation has proposed a classification scheme for chronic kidney disease that has been widely adopted (Table 1Table 1Stages of Chronic Kidney Disease and Prevalence in Adults.). Stage IV chronic kidney disease denotes a severe decline in the GFR to 15 to 29 ml per minute per 1.73 m².1 Table 2Table 2Major Causes of Severe Chronic Kidney Disease. shows the major causes of severe chronic kidney disease among people in the United States.
Several studies have examined the incidence of chronic kidney disease overall, although less is known about the incidence of stage IV disease specifically. Chronic kidney disease (defined in the Framingham Study as a GFR that is <60% of the normal level) developed in about 9% of the subjects in the Framingham Study cohort during an 18-year follow-up period.5 In the Atherosclerosis Risk in Communities study, chronic kidney disease (defined as a persistent rise in the serum creatinine level) developed in 4.4 of 1000 white subjects and 8.8 of 1000 black subjects during a 14-year follow-up period.6 Data from the National Health and Nutrition Examination Surveys of 1988 to 1994 and 1999 to 2004 suggest that the prevalence of chronic kidney disease increased from 10 to 13% over the 10-year period from 1994 to 2004.2 This rise is probably attributable to a progressively aging population and the increased prevalence of obesity, diabetes, and hypertension.
Chronic kidney disease is a well-known risk factor for cardiovascular disease (Figure 1Figure 1Cardiovascular Disease in Patients with Chronic Kidney Disease.). Several conditions (e.g., diabetes and hypertension) may promote the development of chronic kidney disease and, together with proteinuria, are also risk factors for cardiovascular disease.7-9
Less than 2% of patients with chronic kidney disease ultimately require renal-replacement therapy.7 In part, this low rate is explained by the increased risk of death from cardiovascular causes before progression to end-stage renal disease can occur.7,8 Cardiovascular disease is the most frequent cause of death among patients with chronic kidney disease in longitudinal studies, but these studies involve primarily older patients and patients with diabetes and a history of cardiovascular disease.7,8 In a retrospective study of relatively young, well-nourished patients without diabetes and with a low prevalence of proteinuria, cardiovascular disease, and risk factors for cardiovascular disease, there was a higher incidence of kidney failure than of death during the course of the study.9
Cardiovascular complications associated with chronic kidney disease include angina pectoris, myocardial infarction, heart failure, stroke, peripheral vascular disease, arrhythmias, and sudden death (Figure 1).10 The risk of each of these conditions increases from early-stage to advanced chronic kidney disease.10 The increased risk of death and poor outcomes after myocardial infarction in patients with stage III or stage IV chronic kidney disease may be related to the frequent proximity of lesions to the coronary ostia.11 In laboratory animals, uremia is associated with cardiac fibrosis.12 In patients with advanced chronic kidney disease, uremic cardiomyopathy is characterized by diastolic dysfunction, heart failure, and left ventricular hypertrophy; these abnormalities, in combination with myocardial ischemia and electrolyte shifts, probably contribute to the high incidence of sudden death.10

Strategies and Evidence

Evaluation

An approach to the management of chronic kidney disease requires a correct diagnosis of the primary renal disease, attention to coexisting conditions, and an understanding of the systemic complications. Potentially reversible causes that may contribute to the decline in GFR in patients with chronic kidney disease should be identified. These include hypovolemia and hypotension; conditions associated with a decreased effective arterial-blood volume, such as cirrhosis and the nephrotic syndrome; obstructive uropathy, urinary tract infection, or occlusive renovascular disease; the use of nonsteroidal antiinflammatory drugs; and severe hypokalemia or hypercalcemia. A substantial loss of functioning nephrons is associated with functional, structural, and metabolic adaptations that contribute to the glomerular, vascular, and tubulointerstitial changes that are seen in patients with chronic kidney disease (Figure 2Figure 2Mechanisms Underlying the Progression from Early-Stage to Advanced Chronic Kidney Disease.). These maladaptive responses and associated complications are common mechanisms that are not specific to the primary cause of chronic kidney disease but that contribute to the progression of the disease. A comprehensive strategy to treat these complications is essential for slowing the progression to end-stage renal disease.

General Management

Renal function should be followed closely (every 1 to 3 months, depending on the rate of progression), by periodic estimation of the GFR4 (see the Supplementary Appendix, available with the full text of this article at NEJM.org). Although serum cystatin C has been proposed as a reliable marker for the estimation of the GFR, other factors besides the GFR may influence cystatin C levels, and this measurement is not used routinely in practice.13
The guidelines of the Kidney Disease Outcomes Quality Initiative recommend that patients with stage IV chronic kidney disease be referred to a nephrologist.1 However, this recommendation is not widely followed; in one study of U.S. veterans, less than 30% of the veterans with stage IV chronic kidney disease were seen by a nephrologist.14 Although there are no data from clinical trials to establish the optimal referral time, delayed referral of patients with late-stage chronic kidney disease is associated with suboptimal outcomes, including increased mortality.14,15 The practical challenges of providing adequate therapy for patients with chronic kidney disease include the large number of medicines that are often needed and the high rate of coexisting conditions16,17 that require meticulous follow-up at each visit. However, even among patients with chronic kidney disease who receive ongoing care from nephrologists, the management of the disease is not always optimal; the rates of use of ACE inhibitors, aspirin, statins, and beta-blockers that were reported in one study were only 41%, 65%, 24%, and 65%, respectively.17


http://www.nejm.org/doi/pdf/10.1056/NEJMcp0906797