Who Benefits from Guidelines

Have patients benefited from guidelines We do not know. To the extent they are followed, adoption of certain guidelines may well harm some patients. Bringing patients to the K DOQI PTH goal of 150-300 pg ml may be partly responsible for the epidemic of adynamic bone disease. Raising the upper level of hemoglobin from 12 to 13 g dl may harm some patients, considering that higher levels of hemoglobin have been associated with excess mortality in two prospective studies, both of which were stopped...

The Ca Model and Ca Buffer Pool

The model is again depicted in figure 2 where another compartment, termed a Ca 'buffer pool', is shown. This buffer pool is defined as a source of very rapid Ca mobilization (M+Ca) into extracellular fluid (ECW) or sequestration (M-Ca) beyond ECW during dialysis when there is a concentration gradient between plasma and dialysate. As shown quantitatively below, such a Ca pool rapidly buffering changes in plasma concentration was found to be required mathematically to close mass balance of...

Elimination

Besides adding a substantial fraction of convective iP removal to the conventional HD treatment, extending daily or weekly treatment time seems to be the most promising way to neutral phosphorus balance. Hemodia-filtration has been demonstrated to enhance phosphate removal by 30-40 up to 1,200 mg treatment and, on the long-run, to reduce the predialysis plasma iP concentration 13, 14 . Increased intradialytic iP removal has been reported to be associated with a faster and steeper phosphate...

Decreasing Catheter Risk

Dialysis catheters play an important role in the provision of hemodialysis because they can provide immediate access for emergent dialysis and alternatives for patients with inadequate vasculature or medical conditions that preclude alternative access. Ideally catheters function as a short-term bridge to AV fistula or AV graft placement. Unfortunately, catheter use is often prolonged even when not medically necessary. In 2004, 63 of patients maintained on hemodialysis for < 0.5 years, 36 on...

Materials and Methods

The study was divided into two phases. Phase 1 was used for the detection of prevalence and the level of inflammation in the entire dialytic population of the Vicenza hemodialysis center. Blood samples were collected from 81 pa tients under sterile conditions immediately after needle insertion but before any intravenous fluid was given (mid-week dialysis session) to measure the inflammatory parameters and make microbiological analyses (standard and molecular). Phase 2 was used for the molecular...

Restriction and PB Therapy

From a general viewpoint, it can be stated that it should always be possible to reduce intestinal iP absorption to a level which can be balanced by dialysis phosphorus elimination. That neutral phosphorus balance can be achieved with the combined efforts of today's treatment options has been demonstrated by various studies on the efficacy of PBs. In the treat-to-goal study normophosphatemia was achieved within a couple of weeks after study initiation 24 . The 'secret' of this success lies in...

Finding a Safe Path between Scylla and Charybdis

Multiple factors contribute to vitamin C deficiency in dialysis patients dietary restriction, losses during dialysis, and fear of oxalosis. This uncertainty is compounded by difficulties in measurement of plasma vitamin C, which is very unstable in the blood sample 38, 39 . Currently, plasma vitamin C is rarely determined. Standardized clinical methods for measuring plasma vitamin C are urgently needed, which would allow measurement of vitamin C to be done as a routine procedure to assess...

An Alternative Hypothesis

The reduced survival in MHD patients with a low BMI has recently been explained by a novel hypothesis 7 . Briefly, both in healthy and MHD subjects, visceral organ mass (i.e. high metabolic rate compartment, HMRC) relative to whole body mass (HMRC BW) is inversely related to weight and urea distribution volume (V). V, as determined by urea kinetic modeling, is closely related to MM (fig. 1), whereas fat mass contributes only marginally. Viscera are the most likely source of uremic toxins, and...

Hou CdiCa

Plasma Ca profiles calculated from the data of Hou et al. 1 with and without fitting values for M Ca. moval from VCa and recovery in dialysate could be calculated with both sets of measurement and directly compared for validity to predict mass balance. Analysis of their CCaT data with the Ca kinetic model is shown in figure 6 combined with the Hou data. Excellent agreement between the calculated removal from the body and measured recovery in dialysate can be seen over a total flux range...

Clinical and Organizational Monitoring

IMS Working with Guidelines (EBPG) and SOPs Orientation towards quality and continual improvement is a fundamental principle within Fresenius Medical Care and a key element of management policy for all business sectors. Within the Patient Care Business Unit, FME aims to set and achieve higher standards of dialysis care supported by both internal, corporate requirements as well as external standards. FME's overall approach to quality assurance is based on the principles of continuous quality...

What Are the Current Limitations of PB Therapy

Patient incompliance with PB prescription is assumed to be a major reason for hyperphosphatemia including inadequate timing of PB intake in relation to the meal, completely neglecting PB intake and taking less than the prescribed amount. Fixed PB dosing regimens, such as 2 PB pills with each meal, are another problem. This strategy does not take into account the normal day-to-day variations in meal phosphorus content. Our own observations show that dietary iP intake for breakfast, lunch and...

Reconciliation of RCT Results with OS Results

Observational studies result in ever higher minimum adequate dosage recommendation due to the powerful effect of dose targeting error as illustrated by the HEMO data. It is a self-fulfilling prophecy inherent in the design of observational studies. Many patients had to have a reduction in dose to fit even the higher spKt V 1.40 target for the standard arm of HEMO. This caused concern about inadequate dialysis, especially in patients who did not quite reach the spKt V goal of 1.40....

Abstract

A kinetic model of Ca mass balance during dialysis has been developed. It is a single-compartment, variable-volume model to compute Ca mass balance during dialysis in its volume of distribution, the extracellular fluid. The model was used to analyze literature data which were suitable for the assessment of Ca mass balance over the course of dialysis. The modeled analyses predicted the serial plasma Ca concentrations very well. The mass balance analyses revealed a pool of rapidly diffusible Ca...

Problems with High Small Solute Clearances Large K

Blood Flow and Efficiency of Dialysis Short dialysis with fixed Kt Vurea leads to maximization of dialysis efficiency by using higher efficiency dia-lyzers and high blood and dialysate flows however, the influence of blood flow on the efficiency of dialysis is markedly lower than dialysis time. Removal of MMs (including phosphorus) is only slightly dependent on blood and dialysate flows 13 . so compensating shortened dialysis time by increasing blood flow is not effective. This is not only...

Limitations of Studies to Date

The critical point is that BMI does not differentiate between fat and muscle BMI and changes in BMI do not exclusively reflect total adipose tissue mass (TATM) or changes in TATM. MM contributes significantly to BMI, and at any given BMI the relative contributions of TATM (and its components, VAT and SAT) and muscle tissue to it may vary substantially between individuals. Consequently, body composition cannot be inferred from BMI data accurately and across the whole spectrum of BMIs. Moreover,...

Methods

Hemoglobin results for approximately 95,000 patients per quarter were included in this analysis. Patients were included regardless of modality (HD vs. PD), setting (in-center vs. home), admission status (permanent or transient), or medication use. No patients or laboratory results were excluded. For each time period, intra-patient 3-month averages were determined as the mean of all HGB values in the 3 months. For creation of histograms, the 3-month averages were rounded to the nearest 0.1 g dl....

Hemofiltration

Hemodialysis and hemofiltration share a common ex-tracorporeal circuit design blood is continuously extracted from the patient through a central venous catheter or through a specially constructed vascular access. Occlusive roller pumps applied to the blood tubing pull blood from the patient and push it through a hollow-fiber dialyzer, whence it then returns to the patient via the same vascular access device. Attempts to use the patients own blood pressure (continuous arteriovenous...

Introduction

The process of haemodialysis relies upon a diffusive gradient across the membrane contained in the haemo-dialyser or artificial kidney to facilitate solute and fluid removal from the patient during treatment as well as to normalise electrolyte imbalances. To permit this, whilst blood flows on one side of the membrane or is contained within the hollow fibre, dialysis fluid, a buffered electrolyte solution, flows on the outer side of the membrane or around the hollow fibre. This article focuses...

Discussion

The gold standard until the 2006 K DOQI guidelines were adopted was based on the CANUSA study 7 , which clearly showed a difference in mortality between different delivered Kt V values, a 0.1 unit of Kt V increase conferring a 5 advantageous RR of survival. Interestingly the CANUSA study had a higher death rate in US patients compared to Canadians, and the former had a higher BSA. Peritoneal Kt V was 1.5 in Americans and 1.7 in Canadians (the renal Kt V was not different between the 2 groups)....

Conclusions

Looking at the many problems with guidelines we ask, do we really need them at all Why are there no guidelines for dentists, veterinarians, or lawyers These professions have kept control of their destinies by rejecting direct third-party reimbursement, and all the strings that come attached with this. Ultimately, guidelines and P4P become means to bypass the doctor-patient relationship and centrally determine how medical care is delivered. They replace the art of medicine with paint-by-numbers....

Purificaron

W. 111JI I Hemcdktfltiotion (hOF) rfn yS- IV Chinese Society of Blood 111L tlx Hr 1L. Porlflco'lcn Administrotkxi (CS8PAJ C. Ronco, i icenza N.W. Levin, New York, N.Y. Mfilkd ardSftnllfif Nlithns BkH llfitOKI Pdlii l< fcnNe-**< t- HiCJl.ir.d' H. 'I> < Singapore fclr o Sydrej

Absorption

The absorption of drug and nutritional supplements can be reduced or slowed in the CKD patient due to delayed gastric emptying. Given that diabetes mellitus is a common cause of CKD, diabetic gastroparesis is a frequent comorbidity. Delayed gastric emptying will alter the absorption profile of orally administered drugs. The absorption of many drugs is affected by gastric pH. Gastric acidity is reduced in predialysis CKD patients compared to controls 6 . Gastric acidity is further mitigated by...

Calcifications Technical Principles

EBCT has been very well validated in several experimental and clinical studies and has been extensively used in the past for coronary artery calcium scoring. EBCT was therefore considered the reference method (so-called 'gold-standard') for coronary artery calcium scoring against which all new methods must be judged. The heart of the EBCT scanner is a stationary electron gun that runs at a constant tube current of 625 mA and a tube voltage of 130 kV. The EBCT unit generates an electron beam...

Results

The inflammatory markers were evaluated in the whole population (81 patients) and in the same population divided into 2 subgroups a group in which evident causes of inflammation could be clinically demonstrated (43 patients), and a group with inflammation but no evident causes for it (38 patients). The results are shown in table 1. Comparison of the 43 patients with known causes of inflammation with the 38 patients without causes of inflammation reveals a trend to an increase in IL-6 in the...

Architecture Pore Geometry and Steric Hindrance

Existing polymer membranes used in dialysis and ultrafiltration have been extensively studied. The pores in such membranes are formed by extrusion and solvent casting techniques. The geometry and surface chemistry of the pores arise from the chemistry of the polymers and the fluid dynamics of the casting process. In general, the hollow-fiber membranes are fairly thick or employ a multilayer scaffold for mechanical support, and have a distribution of pore sizes rather than a regular array of...

Final OS Anecdote

In 1992 when the data from Charra et al. 11 appeared showing very low mortality with long 6- to 8-hour treatment times, we reported the analysis of our 4-year experience in San Francisco with high flux dialysis 12 and UKM. We examined several of the large international databases and matched each database with respect to age and diabetes to our results with the results shown in figure 15. Certainly the unique data from Charra et al. 11 stand out, but the next lowest mortality rate was in San...

Length with Mortality in Australia and New Zealand

This study was reported simultaneously 4 with the DOPPS study. It was an OS using data from the Australia New Zealand Dialysis Registry (ANZDATA). It is of interest to note that 20 of patients in ANZADATA are on home dialysis which is not a generalizable therapy category with external validity in view of the very low frequency of home dialysis in most countries. Further, the dialyzers most often used are low flux which also raises question about the generalizability of the data. Certainly...

Increasing AV Fistulae

The pathways to increased AV fistula prevalence are now clearly delineated in the K DOQI recommendations and Fistula First change concepts 11, 12 . Patients should be referred for evaluation for access placement approximately 6 months before dialysis initiation. Arterial and venous mapping, typically by ultrasound is performed to identify appropriate vessels for AV fistula creation 13 . This provides visualization of arteries and veins including the approximately 50 of vessels that are not...

Artery Calcifications

In the past numerous imaging modalities have been used to demonstrate coronary calcification, for example fluoroscopy, intravascular ultrasound, EBCT, single-slice CT and MSCT 9 . For a long time fluoroscopy has been used to assess coronary calcifications. However, the capability of fluo- roscopy to detect small calcium deposits is poor. Usually only highly calcified, larger atherosclerotic lesions are detectable with fluoroscopy. In addition, fluoroscopy may suffer from an impaired accuracy...

References

1 Lowrie EG History and organization of the National Cooperative Dialysis Study. Kidney Int Suppl 1983 13 S1-S7. 2 Eknoyan G, Beck G, Cheung A, et al Effect of dialysis dose and membrane flux in maintenance dialysis. N Engl J Med 2002 347 2010-2019. 3 Saran R, Brago-Gresham J, Levin N, Twardowski Z, et al Longer treatment time and slower ultrafiltration in hemodialysis associations with reduced mortality in the DOPPS. Kidney Int 2006 69 1222-1228. 4 Marshall MR, Byrne BG, Kerr PG, McDonald SP...

Microbiological Quality

Febrile reactions were common in the early dialysis procedures. The electrolyte concentrates in use today are manufactured in accordance with internationally recog nised standards such as ISO 13958, Concentrates for Hae-modialysis and Related Therapies. The acid concentrates do not support bacterial growth, however liquid bicarbonate concentrates have been shown to support bacterial growth and there may be a rapid increase in levels after dilution 22 . High levels in the dialysis fluid lead to...

The Goal Achieving Neutral Phosphate Balance

Neutral phosphorus balance is achieved when total body phosphorus generation (GiP) is balanced by total body phosphorus elimination (JiP). Whole body iP generation is dependent on (i) intestinal iP and protein absorption and (ii) the amount of iP released from or deposited in endogenous tissues, such as bone. Phosphate binders (PBs) are used to decrease GiP by effectively lowering intestinal phosphorus absorption. In the face of lacking renal function, iP elimination in dialysis patients is...

Phosphorus Restriction

Hyperphosphatemia would not be a problem without dietary phosphorus ingestion and vascular calcification would most likely be less of a problem. However, although dietary phosphorus restriction is always listed as a corner stone of phosphate management, it is rarely performed successfully in clinical practice for various reasons. (1) Patients need excessive dietary advice and teaching to be able to restrict phosphorus intake while maintaining an adequate protein calorie intake. In healthy...

Vitamin C Effects on Erythropoiesis

The management of anemia utilizes much of the resources dedicated to patients on dialysis hemoglobin, ferritin, transferrin saturation, erythropoietin therapy and the intravenous administration of iron complexes (IV-iron) are reviewed extensively for each patient, with dose adjustments monthly or even at more frequent intervals. Improved vitamin C status may lead to improved anemia management in these patients. The biochemistry of vitamin C and iron are intimately related at the level of the...

MEMS and ECF Volume Sensing

Critical to the success of an automated dialysis platform is on-line real-time estimation of ECF volume, a complex engineering problem in its own right. Esopha-geal Doppler monitoring (EDM), pulmonary-artery catheters, and peripheral waveform analysis all provide measures of central hemodynamic parameters. Bioimped-ance and hematocrit monitoring may provide estimates Fig. 1. Scanning electron micrograph of a silicon nanopore membrane. Scale bar 30 m. The higher-power inset shows a single pore...

Ca Mass Balance over the Complete Dialysis Cycle

Ca mass balance (accumulation in the body) will be determined by the net intake of Ca minus the removal of Ca as schematically depicted in figure 1. The volume of distribution for ionized Ca (VCa2+) is defined as being anatomically equal to the extracellular fluid volume (VECW). The ultrafiltrate during dialysis is considered uniformly removed from VCa, a well-mixed pool of ionized, diffusible Ca 2+. There is virtually no quantitative understanding of the magnitudes of intake, removal and...

Ca Kinetics in Dialysis Therapy

The primary purposes of Ca kinetic modeling during dialysis are (1) to quantitatively assess Ca mass balance during dialysis with current therapy (2) to determine the feasibility of predicting Ca mass balance from key dialysis prescription parameters so that it can be prospective-ly prescribed and controlled in dialysis therapy, and (3) to minimize accumulation and inhibit vascular calcification and mortality. There are no reported studies that we are aware of attempting to develop a model to...

Clinical Assessment of Dialysis Quality

One may ask what index of dialysis adequacy should be used instead of Kt Vurea. It is tempting to give a simple formula, easy to implement and easy for bureaucrats to control. If such a formula were really developed, nephrol-ogists would not be needed in dialysis centers - computer programs and dialysis technicians would suffice. I do not believe that such a formula will be developed any time soon as dialysis is a very complex procedure. The use of rigid, quantitative guidelines (e.g., spKt...

Problems with Short Dialysis Small t

In the first paper on shorter dialysis duration, Schupak and Merrill 7 reported a markedly higher rate of hypertension problems than in the early reports with longer dialysis 5, 6 . The French Dialysis Registry reported a gradual decrease in hemodialysis duration during the 1970s and a higher rate of hypotensive episodes 25 . In 1983, the European Dialysis and Transplant Association reported 'the proportion of deaths in the Federal Republic of Germany was twice as high in short dialysis' 26 ....

Advantages of Long Dialysis Large T

From the above discussion, the advantages of long dialysis to the patients are obvious better tolerance of dialysis, better control of blood pressure, better removal of MMs, better rehabilitation, and longer survival. The average ratio of patients to dialysis personnel is 3-4 to 1 in the US. Because of better tolerance of dialysis with fewer hypotensive episodes, the same ratio in Tassin is 6 to 1 56 . Thus, the financial disadvantage of longer dialysis may be blunted by a reduced staff...

Evolution of Dialysis Duration

In the early 1960s chronic hemodialyses were long procedures, usually 20-40 h week on standard Kiil dia-lyzers in-center 5 or 8-10 h three times weekly at home 6 . The first trials of shorter dialysis duration were at- 2007 S. Karger AG, Basel 0253-5068 07 0251-0090 23.50 0 E-Mail Twardowskiz health.missouri.edu tempted in the late 1960s. Schupak and Merrill 7 indicated that shorter dialysis sessions (total duration of 1216 h week with the use of coil dialyzers) achieved biochemical control...

Justification for Short Dialysis

Three factors were necessary for the widespread acceptance of short dialysis economic incentives, technical feasibility, and medical scientific justification 10 . Economic incentives were demonstrated by early proponents of short dialysis. In the meantime, very efficient dialyzers had been designed and their values demonstrated in short-term studies 11, 12 . Nevertheless, short-term studies would not be sufficient for the widespread use of short dialysis. Some scientific support and a...

Water for the Production of Dialysis Fluid

Generally patients undergoing three times weekly dialysis treatments utilise dialysis fluid flow rates of between 500 and 800 ml min, which corresponds to the use of 120-200 litres of fluid over a 4-hour treatment session. In contrast to the normal population, who not only are exposed to significantly lower volumes of water and in whom the gut offers a high degree of protection from impurities that may be present, dialysis patients are not only exposed to higher volumes of water, but during...

Dialysis Prescription

The only widely accepted method to quantify the dose of dialysis is the fractional clearance of urea from body water or Kt VU, where K is dialyzer urea clearance, t is treatment time and V is the urea distribution volume (KDOQI) which is considered to be a dose surrogate for removal of low molecular weight toxins. There have been two prospectively randomized, controlled trials (RCTs) of dialysis therapy 1, 2 and in both these trials the dialysis dose was tightly controlled with urea kinetic...

Reported Clinical Studies

The model was used to analyze four reported clinical studies 1-4 . The analyses consisted of fitting calculated plasma concentrations to the reported values with the model and the calculation of mass balance as described above and comparing to that reported for dialysate. The serial VCa2+ was estimated as 1 3 of total body water (TBW) considered to average 33 liters. If weight loss was given this was used as total Qf and if not (usually the case) it was assumed to be 2 liters. Discussions of...

Hypertension in Hemodialysis Patients

Hypertension occurs in 90 of patients starting hemodialysis and persists in 70-90 of hemodialysis patients in the US 57 . In the large, multicenter Hemodialysis (HEMO) Study more than 70 of patients were hypertensive by JNC VI guidelines, and almost 75 required antihypertensive medications 58 . This is contrary to the situation in the late 1960s, when strict control of true dry body weight was practiced and the majority of patients did not require antihypertensive agents 59 . There is a...

The NCDS Dosing Controversy and HEMO

In addition to the step function in outcome shown in figure 4 , continuous linear and exponential functions relating probability of failure to Kt V could also be written with equivalent p values as described in the mechanistic analysis paper 7 , Subsequently others strongly argued that outcome should be an exponential function as shown in figure 5A because of accumulating OS experiences which indicated continuing improvement in outcome up to spKt V 1.40 8 , The HEMO study 2 was subsequently...

Changing the Fate of Diabetics in the Dialysis Unit

In a symposium on diseases of kidney reported in 1971 Williem J. Kolff was quoted as saying in 1938, 'Gradually the idea grew in me that if we could only remove 20 g of urea and other retention products per day we might relieve this man's nausea and that if we did this from day to day, life might still be possible' 8 . Dunea 8 started his article after this statement and wrote, 'Within three decades dialysis has revolutionized the field of nephrology and opened new vistas in the treatment of...

Chronic Kidney Disease 2007

9th International Conference on Dialysis, January 24-26, 2007, Austin, Texas Claudio Ronco, Vicenza Nathan W. Levin, New York, N.Y. 57 figures, 6 in color, 23 tables, 2007 Basel Freiburg Paris London New York Bangalore Bangkok Singapore Tokyo Sydney Medical and Scientific Publishers Basel Freiburg Paris London New York Bangalore Bangkok Singapore Tokyo Sydney he statements, options and data contained in this publication are solely those of the individual authors and contributors and not of the...

The Production of Dialysis Fluid

Catridge Renal Care

Historically the production of dialysis fluid was by the manual mixing of concentrated electrolyte solution with water in a large tank, which was then heated and pumped to the dialyser 1 . With the advent of single-patient proportioning systems in the late 1960s, the production of the dialysis fluid moved to the patients bedside and whilst this approach remains the most widely used, alternatives such as a central delivery system or systems that incorporate pre-mixed dialysis fluid continue to...