Biocompatibility of hemodialysis membranes: interrelations between plasma complement and cytokine levels.

Hemodialysis (HD) membrane biocompatibility is defined as absence of complement activation. We have recently shown that circulating levels of interleukin (IL) 1 and IL-2 predict death and survival, respectively, of HD patients. Studies have assessed IL-1 in treatments with biocompatible and less biocompatible dialysis membranes, but no study has correlated circulating levels of all these immunoreactants. We assessed these immunoreactants, and temperature as an outcome, during HD in patients treated with different membranes. Twelve stable patients, receiving thrice-weekly chronic bicarbonate HD, were randomly dialyzed with three different types of membranes, composed of: Cuprophan, cuprammonium rayon modified cellulose, and Hemophan. Blood was drawn from the arterial line port before (Pre) and 15, 30, and 60 min during and after (Post) HD. Patients' temperatures were measured before and after each treatment. The plasma concentrations of IL-1 and IL-2 and factors C3a and C5a were assessed by ELISA. There were no differences between baseline levels of any of the immunoreactants in patients treated with different dialyzers. C3a, C5a, and IL-1 levels increased significantly during HD treatments with all three different membranes. C3a, C5a, and IL-1 levels during Cuprophan and Hemophan treatments were significantly higher than the levels during modified cellulose treatment at 30 and 60 min and Post (p < 0.01). For all the immunoreactants, however, the Post levels were higher than the Pre levels. In contrast to IL-1, there were no differences in mean IL-2 levels during treatments when different membranes were compared. There were few correlations of plasma C3a and C5a levels with plasma IL-1 levels, but there was only one treatment time in one dialyzer group during which IL-2 and any of the other factors were correlated. Pre and Post temperature values and percent change in temperature were not correlated with any of the immunoreactants measured. These data show that C3a, C5a, and IL-1 responses are similar, but not identical, during treatments with different membranes. The response of circulating IL-2 levels to treatments is quite different from that of plasma C3a, C5a and IL-1 levels and suggests that these changes are not solely due to treatment factors. Treatment with modified cellulose membranes is associated with a different immunoreactive profile as compared with patients dialyzed using other cellulose membranes. We suggest that circulating IL-1 levels are good biocompatibility markers.

How a multidisciplinary vascular access care program enables implementation of the DOQI guidelines. Part I.

This comprehensive, proactive, multidisciplinary team approach to access management has enabled the achievement of center-specific best-demonstrated clinical practiCes for vascular access care. It has also resulted in significant cost savings to the health care delivery process. It has not been an easy task; if it were, access care outcomes would be better nationally than they are today. The VACP approach to vascular access care improvement employs four key implementation principles that ensure the success of Gambro's program and form the infrastructure supporting any successful team approach to care. These core processes, known as the four "C's, include: 1. Commitment, 2. Continuous Quality Improvement, 3. Core Competency, and 4. Communication.

Moderate metabolic acidosis and its effects on serum parameters in hemodialysis patients.

We screened the laboratory data of 50 chronic hemodialysis patients selected randomly over a 21-month period to generate 158 data points which identified two groups: (1) those with a predialysis total CO(2) concentration less than or equal to 19 mEq/l (data A; n = 57) and (2) those with a predialysis total CO(2) concentration greater than 19 mEq/l (data B; n = 101). Then, both groups were compared for the following parameters: predialysis blood urea nitrogen (BUN), serum phosphorus, uric acid, creatinine, and albumin concentrations, Kt/V, urea reduction ratio, normalized protein catabolic rate, dry weight, ultrafiltration, blood flow and dialysis flow rates, duration of dialysis treatment, and blood pressure. Group data A had significantly higher predialysis BUN, phosphorus, and uric acid concentrations than group data B. There were significant inverse correlations between predialysis serum bicarbonate and predialysis BUN, phosphorus, and uric acid concentrations. Although it is not clear what the long term side effects of moderate metabolic acidosis are, we recommend its correction.

Lessons learned. Implementing a vascular access quality improvement program. Part II.

Implementing a CQI program for vascular access can seem an overwhelming task. It encompasses many areas that are not in the nephrologists' or dialysis facilities' control. However, involving the right multidisciplinary team members in the process and aligning the goals and objectives creates an environment conducive to success. Ongoing communication is critical. Everyone needs to be a part of the change process.

Outcome of an opportunistic infection after polymicrobial peritonitis in an HIV-infected patient treated with peritoneal dialysis.

The prevalence of human immuodeficiency virus (HIV)-infected patients with end stage renal disease (ESRD) is likely to increase and many of them will be on peritoneal dialysis as renal replacement therapy. Infectious complications are a major problem associated with peritoneal dialysis (PD). It has been speculated that the HIV-positive peritoneal dialysis population may develop peritonitis more frequently than other peritoneal dialysis patients. We present the complications and unexpected good response to medical management of PD-associated peritonitis in a young HIV-infected black male. He had two unusual and serious infections; the first was a polymicrobial peritonitis which predisposed the patient to an unusual infection caused by Corynebacteria JK for which he was successfully treated without catheter removal.

Women issues in female patients receiving peritoneal dialysis.

About 50% of the population receiving peritoneal dialysis (PD) in the United States are women. Nephrologists generally address medical issues related to end-stage renal disease, ie, anemia, hypercholesterolemia, secondary hyperparathyroidism. In female PD patients, specific topics should also be addressed. They include menstruation, birth control methods, osteoporosis, child bearing, postmenopausal hormone replacement and its consequences, screening of gynecological malignancies, sexual problems, and hemoperitoneum. We briefly describe in a multidisciplinary view the management of these issues.

The impact of residual renal function and total body water volume on achieving adequate dialysis in CAPD.

AIMS: The objective is to evaluate the impact of residual renal function (RRF) and total body water (TBW) on achieving adequate dialysis. METHODS: Sixty three CAPD patients performing four 2 liter exchanges daily were evaluated for RRF, total weekly Kt/V (TWKt/V), total weekly creatinine clearance (TWCC) and TBW. RESULTS: In patients with residual renal function (N = 41), TWKt/V and TWCC were 2.2 +/- 0.8 and 77.4 +/- 24.5 L, respectively. In patients without RRF (N = 22), TWKt/V was 1.6 +/- 0.4 and TWCC 42.6 +/- 9.2 L. TBW correlated negatively with TWKt/V in the group without RRF (r = -0.75, P<0.001). CONCLUSION: It is not possible for larger patients without RRF treated with CAPD (2L x 4 exchanges) to achieve the acceptable targets for TWKt/V and TWCC due to TBW.

Biochemical parameters, nutritional status and efficiency of dialysis in CAPD and CCPD patients.

BACKGROUND/AIMS: Several studies indicate that small solute transport is influenced by peritoneal dialysate volume and dwell time. This study focuses on the clinical impact of peritoneal dialysis modality, continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD). METHODS: We studied 18 patients on CAPD and 11 on CCPD for 18 months and assessed biochemical parameters, nutritional status and efficiency of dialysis at 6-month intervals. RESULTS: Four-hour D/P urea and creatinine ratios were similar in both CAPD and CCPD patients. However, 24-hour D/P urea and creatinine ratios were significantly higher in CAPD than in CCPD patients (0.9 +/- 0.1 vs. 0.8 +/- 0.2 and 0.8 +/- 0.1 vs. 0.6 +/- 0.2, p < 0.05 and p < 0.01, respectively). The dialysate urea nitrogen concentration was significantly different between the two groups (65 +/- 14 mg/dl in CAPD, 48 +/- 13 mg/dl in CCPD; p < 0.05). Total weekly Kt/V and total weekly creatinine clearance were not significantly different between CAPD and CCPD patients at 18 months (1.6 +/- 0.4 vs. 1.7 +/- 0.3 and 52 +/- 21 vs. 50 +/- 12 liters, respectively). Two-way ANOVA with a post-hoc Bonferroni-Dunn test showed serum potassium concentration was significantly lower in CCPD patients at 18 months (3.8 +/- 0.5 mEq/l, p < 0.05), and significant increases in triglyceride levels in the CAPD groups by 18 months (301 +/- 286 mg/dl, p < 0.05). CONCLUSION: This study demonstrates that the mean serum triglyceride level increases in CAPD patients over time, and the mean serum potassium concentration decreases in CCPD patients at 18 months. Dialysis adequacy and nutritional status are not significantly different between the two peritoneal dialysis modalities, CAPD and CCPD. We suggest the peritoneal dialysis prescription for CAPD or CCPD with respect to volume and frequency of exchanges be individualized to achieve adequate of therapy.

A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group.

BACKGROUND: Serum creatinine concentration is widely used as an index of renal function, but this concentration is affected by factors other than glomerular filtration rate (GFR). OBJECTIVE: To develop an equation to predict GFR from serum creatinine concentration and other factors. DESIGN: Cross-sectional study of GFR, creatinine clearance, serum creatinine concentration, and demographic and clinical characteristics in patients with chronic renal disease. PATIENTS: 1628 patients enrolled in the baseline period of the Modification of Diet in Renal Disease (MDRD) Study, of whom 1070 were randomly selected as the training sample; the remaining 558 patients constituted the validation sample. METHODS: The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equations in the validation sample. RESULTS: To simplify prediction of GFR, the equation included only demographic and serum variables. Independent factors associated with a lower GFR included a higher serum creatinine concentration, older age, female sex, nonblack ethnicity, higher serum urea nitrogen levels, and lower serum albumin levels (P < 0.001 for all factors). The multiple regression model explained 90.3% of the variance in the logarithm of GFR in the validation sample. Measured creatinine clearance overestimated GFR by 19%, and creatinine clearance predicted by the Cockcroft-Gault formula overestimated GFR by 16%. After adjustment for this overestimation, the percentage of variance of the logarithm of GFR predicted by measured creatinine clearance or the Cockcroft-Gault formula was 86.6% and 84.2%, respectively. CONCLUSION: The equation developed from the MDRD Study provided a more accurate estimate of GFR in our study group than measured creatinine clearance or other commonly used equations.

Peritoneal dialysis-associated peritonitis caused by Propionibacteria species.

There are an increasing number of reports about unusual causes of peritonitis in peritoneal dialysis (PD) patients. The Propionibacteria species is a microorganism that is a normal skin flora. Under the presence of certain risk factors, it may produce serious infections. Patients at risk of having Propionibacteria sp infections have malignancy, diabetes mellitus, foreign bodies, or immunodeficiency. We describe a PD-associated peritonitis in a 51-year-old woman that was caused by Propionibacteria sp. This patient's risk factors for developing Propionibacteria sp peritonitis include a history of CREST syndrome, malignancy of the breast, and recent catheter surgery. To our knowledge, this is the first case of a PD-associated peritonitis caused by Propionibacteria sp reported in the literature.

Hemofiltration and double high flux dialysis: risks and benefits.

Convective therapies such as hemofiltration, hemodiafiltration and double high flux dialysis have been shown to improve treatment delivered and treatment tolerance when compared to conventional dialysis therapies. The risk associated with these treatments is primarily in the quality of the substitution fluid. Technological advances now permit on-line produced substitution fluid, thereby significantly reducing the cost associated with hemofiltration and hemodiafiltration. The quality of the substitution fluid is only assured when the quality of the RO water used is within the guidelines set by the Association for the Advancement of Medical Instrumentation (AAMI). Therefore, the success of the application of this therapy is dependent on the water treatment protocols in the dialysis units. The success of this modality as a treatment for chronic renal failure is dependent on identifying those patient groups who will benefit most from this more efficient but more expensive treatment.

Treatment of human immunodeficiency virus (HIV)-associated nephropathy.

Patients with human immunodeficiency virus (HIV) nephropathy (HIVN) face improved outlooks both before and after starting renal replacement therapy for end-stage renal disease, compared with the situation a little over a decade and a half before, when the disease was first recognized. Therapy with cyclosporin, glucocorticoids, and angiotensin-converting enzyme inhibitors provides the prospect of longer courses of renal insufficiency for patients with HIVN, and perhaps the hope of blunting progression of the disease when patients are treated early. Trials of patients with biopsy-proven HIVN are important to evaluate further the role of such newer therapies. HIV-infected patients with end-stage renal disease have been treated with hemodialysis, peritoneal dialysis, and renal transplantation. The course of therapy for dialysis patients may be improving, but ultimately depends on the stage of the viral illness. The disparities in the demographic composition of the patient populations probably underlies findings reported from different centers. Transplantation is currently a low-priority treatment option for HIV-infected patients with ESRD, but several studies provide fascinating insights into viral-host interactions.

Assessment of PD treatment delivered by 125I-Iothalamate plasma disappearance.

The calculation of treatment delivered to PD patients requires the collection of PD effluent, plasma and urine samples. 125I-Iothalamate plasma disappearance, which eliminates the need for PD effluent collections, was tested as an alternate method to measure the weekly PD treatment delivered. Two protocols were designed. In protocol A, a 35 microCi dose of 125I-Iothalamate was injected in three subjects and allowed to equilibrate. A plasma sample was taken and patients returned on both of the following two days with timed labeled effluent bags and a 24-hour urine collection for each day. The timed PD effluent and 24-hour urine collections were measured for 125I-Iothalamate, urea and creatinine concentrations. 125I-Iothalamate and urea clearances were strongly correlated for both PD (R2 = 0.76, n = 24) and renal (R2 = 0.92, n = 6) clearances. In protocol B, thirteen subjects were given a 35 microCi injection of 125I-Iothalamate. A blood sample was taken one hour post injection and a second blood sample taken on day five. Kt/V were calculated from the 125I-Iothalamate plasma disappearance curve and compared to weekly Kt/V values extrapolated from one day's collections (Traditional Method). The comparison of Kt/V values found by 125I-Iothalamate Method vs. the "Traditional Method" yielded R2 = 0.79, n = 13. In conclusion, the plasma disappearance of 125I-Iothalamate is an alternate method of determining weekly Kt/V, over an extended period of time, which eliminates the need for PD effluent collections.

Equal levels of blood pressure control in ESRD patients receiving high-efficiency hemodialysis and conventional hemodialysis.

The present study compared the status of hypertension and adequacy of blood pressure control in 73 end-stage renal disease (ESRD) patients treated with four different modalities of hemodialysis, namely, conventional hemodialysis (CHD) with cuprophan 1.1 m2 at a blood flow rate of 300 mL/min, high-efficiency hemodialysis (HED) with cuprophan 1.6 m2 at a blood flow rate of 450 to 500 mL/min, high-flux hemodialysis (HFD) with F80 polysulfone 1.8 m2 at a blood flow rate 500 mL/min, and high-flux hemodiafiltration (HDF) with F80 2 x 1.8 m2 in series at a blood flow rate of 600 to 650 mL/min. Thirty of the 73 patients (41%) were receiving one or more antihypertensive agents to control their hypertension. The percentage of patients taking antihypertensive medication was less in the groups treated with HED, HFD, and HDF compared with the CHD group: 38%, 39%, and 39%, respectively, in the HED, HFD, and HDF groups versus 56% in the CHD group. Control of systolic and diastolic hypertension was achieved in a higher percentage of patients treated with HED, HFD, and HDF compared with patients treated with CHD. Sixty-two percent of HED, 58% of HFD, and 61% of HDF patients compared with 44% of CHD patients had systolic blood pressure less than 150 mm Hg, whereas 77% of HED, 76% of HFD, and 78% of HDF patients compared 56% of CHD patients had diastolic blood pressure less than 90 mm Hg. However, the differences in the use of antihypertensive medication and control rates of hypertension did not reach statistical significance. The average blood pressure of all patients was 144/89 mm Hg; this did not differ significantly between the four groups. There also were no significant differences in etiology of ESRD, hematocrit, biochemical data, as well as use and dose of recombinant human erythropoietin between the four groups. Compared with the CHD patients, the average treatment times with high-efficiency treatments were shorter, with HDF patients showing the shortest mean treatment time of 157+/-41 minutes per hemodialysis session. The mean Kt/V was higher in the groups treated with HED, HFD, or HDF (1.31+/-0.3, 1.30+/-0.4, and 1.43+/-0.3, respectively) than in the CHD group (1.12+/-0.3; P < 0.05). Interdialytic weight gain also did not differ among the four groups. There was no correlation between predialysis mean arterial pressure and either treatment time (r = 0.04, P = NS), Kt/V (r = 0.03, P = NS), ultrafiltration rate (r = 0.06, P = NS), or interdialytic weight gain (r= -0.08, P = NS). There also was no significant association between Kt/V and use of antihypertensive medications (chi-square = 1.76, P = NS). There was, however, a significant positive correlation between interdialytic weight gain and treatment time (r = 0.33, P < 0.01). We conclude that the use of short dialysis sessions with efficient hemodialysis treatments, namely, HFD and HDF, was associated with similar levels of blood pressure control in ESRD patients.

The effects of increasing exchange volume and frequency on peritoneal dialysis adequacy.

AIM: Peritoneal dialysis adequacy guidelines are generally not met with the standard prescription of continuous ambulatory peritoneal dialysis (CAPD), four 2-liter (1) exchanges daily. The aim of this study is to determine the effects of increasing exchange volume singularly or in combination with frequency on peritoneal dialysis adequacy. PATIENTS AND METHODS: Fourteen stable ESRD patients receiving peritoneal dialysis were evaluated for adequacy and nutritional status between the fourth and sixth months during a six-month baseline period in which the dialysis prescription was four two-liter exchanges daily and during a six-month intervention period in which patients (n = 7) from group 1 were prescribed CAPD four 2.5-liter exchanges daily while patients (n = 7) from group 2 were prescribed continuous cycling peritoneal dialysis (CCPD - 12 l) using four 2.5 liters during the night and a 2-liter wet day. RESULTS: Mean total weekly urea Kt/V (TWKt/V) increased significantly from 1.6 +/- 0.2 to 2.1 +/- 0.2, p <0.01 in group 1, and from 1.6 +/- 0.4 to 2.1 +/- 0.5, p <0.001 in group 2. Mean normal total weekly creatinine clearance increased significantly from 51 +/- 11 to 60 +/- 8 l/1.73 m2, p <0.05 in group 1, and from 45 +/- 6 to 58 +/- 9 l/1.73 m2, p <0.01 in group 2. Serum albumin of almost all patients in the intervention groups were higher than in the baseline groups. Mean serum albumin increased from 3.6 +/- 0.4 to 4.0 +/- 0.4 g/dl, p <0.01 in group 1, and from 3.8 +/- 0.2 to 4.0 +/- 0.4, p <0.05 in group 2. The magnitude of the decrement in BUN and serum creatinine were greater in group 2 than group 1 (p <0.001 and p <0.05, respectively). When the two intervention groups were compared to each other, no significant differences in the delivered dialysis dose or nutritional status were noted. CONCLUSION: In conclusion, it is possible to achieve currently proposed adequacy target by increasing the exchange volume singularly or in combination with frequency in most peritoneal dialysis patients.

Capitation in nephrology: the time has come.

Nephrology represents a powerful example of the impact of new medical technology; almost 200,000 patients are alive in the United States because of renal replacement therapy. However, ESRD patient morbidity and life expectancy are still serious concerns despite advances in medical treatment. A capitated payment system for end-stage renal disease (ESRD) could be a great benefit to the renal community as it would force us to rethink the way ESRD care is provided. By applying the concepts of integration of services, disease management, and case management to ESRD care under a capitated payment system, providers may be able to improve patient outcomes and overall well-being.