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...

Abstract

In our efforts to meet the vitamin C requirements of dialysis patients we confront a medical dilemma - do we allow the patient to become depleted of vitamin C, with the accompanying hematological and other consequences (Scylla), or do we provide for adequate tissue levels of vitamin C, which has been thought to carry the risk of oxalosis (Charybdis). Many practitioners are certain that either one outcome (deficiency) or the other (oxalic acid toxicity) is inevitable, and much like Odysseus, no...

Introduction

The average age of the dialytic population has increased by about 2 years in the past 3 years. This is due to the fact that, on average, new incident patients are older and the prevalent patients (those already on dialysis) are surviving to a much older age. In addition, there has been an increase in the transplantation rate which normally affects younger patients. The number of diabetic patients has also increased at the same pace, and similarly the incidence of patients with catheters has...

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

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...