High-intensity hemodialysis: the wave of the future?

Various modalities of high-intensity hemodialysis are gathering increasing popularity. Some of the advantages of these new dialysis regimens are presented. Time and the increasing use of these novel approaches will ultimately determine their role in the overall management of patients with endstage renal disease.

Triage: Napoleon to the present day.

Triage, the sorting of patients according to the severity of their injuries and the need for urgent surgery was a concept developed by Dr. Larrey, a military surgeon in Napoleon's army. The evolution of the concept in military medicine from that time to the present is described. Triage in civilian practice first became a serious issue with the development of dialysis for chronic renal failure in the 1960s and the problem of the allocation of this scarce and very expensive treatment. With new developments in organ transplantation and technology it continues to be an issue today.

Health-related quality of life among dialysis patients in Seattle and Aichi.

We used the 36-item Short-Form Health Survey to compare health-related quality of life (HRQOL) between 104 dialysis patients in Seattle, WA, and 2,178 patients in Aichi, JAPAN: Compared with Aichi patients, Seattle patients had lower scores on three scales related to physical HRQOL: Physical Functioning (PF; P = 0.03), Role-Physical (RP; P = 0.004), and Vitality (VT; P < 0.001). However, scores related to mental HRQOL were higher for Seattle patients compared with those of Aichi patients, which included scores for Role-Emotional (RE; P = 0.005) and Mental Health (MH; P < 0.001). Scores for Bodily Pain, General Health Perception, and Social Functioning did not differ significantly between the two groups. These differences persisted even after potential confounding factors were controlled for. However, after taking into account national norm data for the United States and Japan, differences in PF and VT disappeared, whereas differences in RP, RE, and MH persisted. These results suggest that the higher scores for PF and VT in Aichi patients were partly explained by the higher physical HRQOL of the Japanese general population. Although these data may not be representative of the total dialysis populations in the United States and Japan, they suggest potential differences in HRQOL between patients in the two countries. Additional research is needed to confirm these results and understand the factors associated with these differences. The findings suggest the need for further attention to the physical limitations of US dialysis patients and the mental health of Japanese dialysis patients.

Pentosan polysulfate decreases proliferation and extracellular matrix deposition by vascular smooth muscle cells isolated from failed hemodialysis access grafts.

BACKGROUND: Vascular access failure is a major cause of morbidity, and increased costs in patients undergoing maintenance hemodialysis. Stenosis, the most common underlying cause of loss of patency in failed grafts, appears to be caused by an obstructing mass of tissue containing proliferating smooth muscle cells and their associated extracellular matrix. METHODS: To determine whether this process was amenable to pharmacologic intervention and/or prevention, we obtained samples of the material occluding vascular accesses from 7 patients undergoing revision surgery in order to characterize the cells contributing to the stenosis. In all 7 patients the outgrowth contained predominantly smooth muscle-like cells admixed with fibroblasts, which produced a large amount of type IV and type I collagen. RESULTS: Treatment with pentosan polysulfate inhibited cell proliferation and significantly reduced the accumulation of types I and type IV collagens. This was associated with increase in metalloproteinase-9 (MMP-9) and a shift of tissue inhibitor of metalloproteinase-3 (TIMP-3) from the cell layer into the medium. CONCLUSION: These data suggest that pentosan polysulfate (PPS) may have a favorable effect in patients with a polytetrafluoroethylene (PFTE) graft by decreasing cell proliferation and collagen deposition.

Dialysate made from dry chemicals using citric acid increases dialysis dose.

A new dry dialysate concentrate acidified with citric acid (citrate dialysate) has been used in two separate clinical studies of hemodialysis patients. The first compared a single treatment using this dialysate, with one dialysis using regular standard dialysate acidified with acetic acid (regular dialysate) in a prospective, randomized, crossover study of 74 dialyses. Changes in blood levels of electrolytes and other blood constituents during dialysis were calculated by subtracting postdialysis from predialysis blood concentrations. Compared with acetic acid dialysate, citrate dialysate was associated with significantly greater decreases in total and ionized calcium, magnesium, and chloride levels. Citrate dialysate was also associated with greater increases in serum sodium and citrate concentrations, although their postdialysis concentrations remained within or just outside normal ranges. Changes in other blood constituents were similar with both dialysates. The second study used citrate dialysate exclusively for all dialyses over a 12-week period in 25 patients. Predialysis blood samples were drawn at the start of the study and at 4-week intervals thereafter, and postdialysis blood samples were obtained after the first and last dialysis. Repeated-measure analysis showed that although predialysis blood concentrations of magnesium, potassium, and citrate remained within the normal range, there was a significant declining trend over the course of the study. At the same time, predialysis serum bicarbonate levels increased, and significantly more patients had a predialysis bicarbonate concentration within the normal range at the end of the study than at the start (15 versus 8 patients; P = 0.001, chi-square). In 19 patients (excluding 3 patients for whom the type of dialyzer was changed during the study), the dose of dialysis for the first and last dialysis was calculated by urea reduction ratio and Kt/V. There was a significant increase in both measurements without changes in dialysis time, blood and dialysate flows, or dialyzer used. The urea reduction ratio increased from 68% +/- 5.9% to 73% +/- 5.3% (P < 0. 03), and the Kt/V from 1.23 +/- 0.19 to 1.34 +/- 0.20 (P = 0.01) from the first to last dialysis, respectively. In conclusion, this citric acid dialysate was well tolerated, and intradialytic changes in blood chemistries were similar to those seen with regular dialysate. Using dialysate containing citric instead of acetic acid increases the delivered dialysis dose.

Exercise coaching and rehabilitation counseling improve quality of life for predialysis and dialysis patients.

Advances in medical treatment have improved the rehabilitation potential of predialysis (P) and dialysis (D) patients, but deficits remain in their physical and vocational functioning. We studied 18 P (expected to begin dialysis in 6-12 months) and 18 D patients (on dialysis 1-5 years) for 1 year. Exercise coaching and rehabilitation counseling were provided at no cost for the first 6 months to half of each patient group (rehabilitation group = R); the other half were assigned randomly to controls (C). No R services were provided during 6 months of follow-up. PR walked further in 6 min at 6 months (+3.9 m) and 12 months (+4.1 m) than initially (p < 0.01). Hematocrit increased in R (p < 0.05), but not in C. Symptom scores were stable in D, worsened 21% in PC, and improved 15% in PR. Sickness impact profile scores were better in PR than PC at 6 months (p < 0.05) and 12 months (NS). Comorbidity correlated with symptoms (r = +0.34, p < 0.05), self-rated affect (r = -0.35, p < 0.05), and self-rated Karnofsky index of disability (r = -0.37, p < 0.05), but not with physician-rated affect or physician-rated Karnofsky index of disability. Thus, quality of life was stable or improved in PR, but declined in PC; PR benefited more than DR. Rehabilitation services are more beneficial before than after patients stabilize on dialysis, and quality of life monitoring should continue indefinitely.

The early years of chronic dialysis: The Seattle contribution.

Long-term hemodialysis for chronic renal failure first became possible with development of the Teflon shunt by Belding Scribner and coworkers at the University of Washington, Seattle, in 1960. Over the next 4 years, many of the advances in dialysis occurred in Seattle. These included recognition and treatment of complications such as malignant hypertension, gouty episodes due to uric acid accumulation, subcutaneous calcification, anemia, iron overload, and peripheral neuropathy. Technical advances included improving the shunt, and in collaboration with Professor A.L. Babb, development of a proportioning system to make dialysate from concentrate and water and the first automated home hemodialysis machine. Dr. Boen and Dr. Tenckhoff developed automated peritoneal dialysis equipment and peritoneal access devices. The world's first outpatient dialysis center, the Seattle Artificial Kidney Center, was established in 1962, and used an anonymous lay committee to select from medically suitable patients those to be treated by the center. This triage was an important step in the development of biomedical ethics, and in 1964, Scribner's presidential address to the American Society for Artificial Internal Organs discussed the problems of patient selection, termination of treatment, patient suicide, death with dignity, and selection for transplantation.

Comparison of mortality with home hemodialysis and center hemodialysis: a national study.

We sought to determine whether lower mortality rates reported with hemodialysis (HD) at home compared to hemodialysis in dialysis centers (center HD) could be explained by patient selection. Data are from the United States Renal Data System (USRDS) Special Study Of Case Mix Severity, a random national sample of 4,892 patients who started renal replacement therapy in 1986 to 1987. Intent-to-treat analyses compared mortality between home HD (N = 70) and center HD patients (N = 3,102) using the Cox proportional hazards model. Home HD patients were younger and had a lower frequency of comorbid conditions. The unadjusted relative risk (RR) of death for home HD patients compared to center HD was 0.37 (P < 0.001). The RR adjusted for age, sex, race and diabetes, was 44% lower in home HD patients (RR = 0.56, P = 0.02). When additionally adjusted for comorbid conditions, this RR increased marginally (RR = 0.58, P = 0.03). A different analysis using national USRDS data from 1986/7 and without comorbid adjustment showed patients with training for self care hemodialysis at home or in a center (N = 418) had a lower mortality risk (RR = 0.78, P = 0.001) than center HD patients (N = 43,122). Statistical adjustment for comorbid conditions in addition to age, sex, race, and diabetes explains only a small amount of the lower mortality with home HD.

A brief history of home hemodialysis.

Home hemodialysis for the treatment of end-stage renal disease was first developed in the early 1960s. Because of the benefits and cost-effectiveness, this modality of treatment was increasingly used; by 1973, when the Medicare End-Stage Renal Disease Program began, approximately 40% of all dialysis patients in the United States were on home hemodialysis. Since then, both the percentage and the number of patients on this treatment has steadily decreased, and such patients now comprise approximately 1.3% of the US dialysis population. Nevertheless, there has been a recent resurgence of interest in home hemodialysis, particularly related to reports of excellent results with daily home hemodialysis and the development of new equipment specifically designed for use in the home. Thus, this modality of treatment may be used more widely in the near future.

Quantitation of hepatitis C viral RNA in sera of hemodialysis patients: gender-related differences in viral load.

Hepatitis C virus (HCV) infection is common in hemodialysis patients, as determined by antibody assays and qualitative polymerase chain reaction (PCR) analysis of serum HCV RNA. To further characterize HCV infection in this population, we measured the viral load in infected hemodialysis patients by a quantitative, competitive PCR assay (QC-PCR) for HCV RNA. Hepatitis C virus RNA levels were correlated with serologic, biochemical, and demographic features of a cohort of hemodialysis patients. Sera from 208 hemodialysis patients were screened for HCV RNA (5' conserved region) by reverse transcriptase PCR (RT-PCR) and HCV-specific antibody. Forty-four patients were antibody positive (21%); among these patients, 34 (77%) were HCV RNA positive. No viremic, seronegative patients were identified. Hepatitis C virus RNA levels quantitated by QC-PCR ranged from 3 x 10(5) to 10(8) molecules of HCV RNA/mL. Male patients had significantly higher mean and median HCV RNA levels (10(7) molecules/mL) compared with female patients (3.6 x 10(6) molecules/mL and 3 x 10(6) molecules/mL, respectfully; P = 0.02). No other demographic or clinical feature of this cohort correlated with HCV RNA levels. Intravenous drug abuse was the most frequently identified risk factor (29% of seropositive patients) for infection with HCV in this population. No association between HCV RNA levels and hepatic enzyme levels (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase) was apparent. Hepatitis C virus infection is highly prevalent in our hemodialysis population, and hemodialysis patients, particularly males, have high levels of HCV in serum.(ABSTRACT TRUNCATED AT 250 WORDS)

The socioeconomic impact of rehabilitation.

Rehabilitation of patients with end-stage renal disease (ESRD) should encompass all aspects of the patient's well-being and include vocational, physical, and medical therapies. This would be best achieved by careful management of the patient before the start of dialysis, as well as by provision of adequate dialysis in the most appropriate setting for the individual patient's needs. Before starting dialysis, blood pressure should be well controlled, nutrition maintained, and human recombinant erythropoetin (epoetin) used as necessary to prevent the development of anemia. In patients who are employed, efforts should be made to maintain employment, and vocational counseling should be provided to unemployed patients who are capable of work. Physical well-being should be maintained by encouraging participation in an exercise program. Social, financial, and other counseling should be provided as necessary, together with patient education regarding treatment, including modalities and other aspects of care. The social impact of these efforts primarily will be on the patient's quality of life, and secondarily, on family members and friends. Quality of life depends on many factors, including modality of treatment and adequacy of dialysis. Economic impact also depends on many factors. Providing optimal care before starting dialysis, including the use of epoetin where appropriate, will increase the cost both for drugs and staff. For patients who are able to continue working or can be successfully retrained, these costs will be offset to some degree in the future by taxes paid by the patient and by the patient not participating in the Social Security Disability Insurance (SSDI) and the Supplemental Security Income (SSI) programs.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum albumin concentration-related Health Care Financing Administration quality assurance criterion is method-dependent: revision is necessary.

The objective of this study was to examine quantitative differences between the two commonly used methods for determining serum albumin concentration, bromcresol green (BCG) and bromcresol purple (BCP), in normal subjects and in 235 unselected dialysis patients in view of recently established Health Care Financing Administration (HCFA) quality assurance review criteria. The mean of normal results by the BCG method was 4.4 g/dL, and 97.5% of values were 3.8 g/dL or higher. The mean of normal results by the BCP method was 3.9 g/dL, and 97.5% of values were 3.3 g/dL or higher. Serum albumin concentrations in samples from the dialysis patients had respectively lower mean values by both methods. For the BCG method, the mean was 3.8 g/dL, and 82% of values were 3.5 g/dL or higher; for the BCP method, the mean was 3.3 g/dL, and 82% of values were 3.0 g/dL or higher. Likewise, for the reference immunonephelometric procedure, the mean value for the dialysis patients was 3.3 g/dL, and 82% of values were 3.0 g/dL or higher. For the samples from the dialysis patients, in comparison with the immunonephelometric method, the BCG method exhibited both constant (intercept = 9.3 g/L) and proportional error (slope = 0.87). The mean albumin value for the BCG method was 3.8 g/dL, 15% higher. In contrast, the BCP method compared closely with the reference method: slope = 1.00, intercept = 0.8 g/L, mean x = 3.3 g/dL, mean y = 3.3 g/dL. The HCFA quality assurance criteria are valid only for the BCG method.(ABSTRACT TRUNCATED AT 250 WORDS)