Best Quality Treatment for Patient Well Being: A Way to Reduce Social Costs and Alleviate Personal Suffering in Dialysis

• Hemodialysis
• Quality of life
• AFB
• Biofeedback system

Introduction

The problem of the quality of life of the patients undergoing renal replacement therapy has in recent years become a crucial issue for dialysis operators, on the one hand due to the natural need to improve the quality of the treatments ((in relation to the increasingly critical conditions of the patients they are addressed to)) ((De Vecchi, [1995])), while on the other due to the unavoidable obstacle of containing the treatment costs ((Società Italiana di Nefrologia, [1997])).

Matching a good quality treatment with a reduction in overall costs is not merely a bookkeeping operation but one that can only be faced in terms of the best possible compromise.

In particular, we can single out two strands: the first one is the containment of direct costs relating to materials and facilities ((currently amounting to 30 and 70 per cent of the dialysis costs, respectively ((Società Italiana di Nefrologia, [1996])))) by the optimisation of the process of service delivery; the second regards the induced costs deriving from the reactions linked to the dialysis therapy ((not yet quantified)) by means of the improvement in the quality of the treatments.

Optimisation of the Service Delivery

Dialysis is a kind of therapy that from certain points of view easily lends itself to process automation. In order to achieve this goal the general concept is to transfer as far as possible the complexity of the operators' processes both on board the machine and on the computerised media. In particular, the phases of the dialysis treatment that can be automated are: 1)) the preparation and management of the machine ((for example, during the preparation of the circuit for extracorporeal circulation, AUTOPRIMING™, Hospal Bologna–Italy)); 2)) the prescription and the therapy ((pre‐‐set and memorised on the specific media DIALPASS™, Hospal Bologna–Italy, or sent via network by computer)); 3)) the management of the dialysis session by means of various monitoring systems ((such as automatic blood pressure, heart rate and blood volume monitors associated to the use of pre‐‐set, personalized alarm thresholds)) by which to intervene successfully and quickly upon the early patient symptoms or even to prevent their onset; 4)) the management of the therapy by means of non‐‐invasive low‐‐cost devices to measure and control the quality of the treatment ((devices for the measurement of the filter dialysance and the volume of purified blood)); 5)) collection and management of the information the machine can supply to the operator ((DIALMASTER™, Hospal Bologna–Italy)), 6)) completion and printing of the dialysis and clinical form. The results and the indications coming from the dialysis centres in which the systems have been adopted show the significant saving in medical‐‐paramedical staff time, and the reduction in the number of interventions and treatments generated by a mistaken prescription and mismanagement of the therapy ((Briganti et al., [1998])).

Quality of the Therapy

Dialysis is a strongly invasive kind of treatment, so an improvement in the patient's clinical picture must necessarily take place through the use of methods that involve the least impact.

Hence, the final goal has to be a device capable of reproducing all the functions of the biological system that it must replace, by continuously reading the status of the rest of the body and reacting in such a way as keep it in stationary and optimal conditions ((artificial organ concept)).

In dialysis therapy a device that matches the definition of an artificial organ must provide for: 1)) the use of more biocompatible materials, 2)) physiologically re‐‐establishing the hydro–electrolytic and acid base.

The biocompatibility of the materials has a marked impact upon the patients' mortality and morbidity as has been already demonstrated several times. Hakim et al. (([1996])) highlighted the fact that the mortality risk is reduced by about 20%% by passing from a cellulose membrane to synthetic ones; Levin and Zasuwa (([1993])) underlined the reduction in the severity of the symptoms associated to the use of more or less biocompatible membranes.

The recovery of the acid–base and hydro–electrolytic balance can be achieved by trying to make the function of the dialysis equipment similar to that of the natural organ. The correction of interdialytic acidosis, simply regulating the mass balance of the hydrocarbon ion alone, is the method that comes closest to the renal control of acidosis. Acetate Free Biofiltration, AFB, born with precisely that goal in mind, achieves a simple correction of the level of plasma bicarbonate, which can be personalised and is capable of not interfering with the patient's cardiovascular stability thanks to the absence of the acetate buffer in the dialysis bath.

The results obtained by changing from bicarbonate dialysis to AFB have demonstrated a reduction in interdialytic symptoms from 45.6 %% to 22.3 %% ((Zucchelli et al., [1994])).

The patient's wellbeing is mostly perceived in relation to the critical degree of the patient him//herself. For instance, it has been shown ((Figure 1)) that in diabetic patients a statistically significant reduction in intra‐‐ and inter‐‐dialysis symptoms is obtained by passing from traditional bicarbonate dialysis to AFB, even if presenting equal values of natremia and mean arterial pressure ((Verzetti et al., [1998])). Analogous results have been obtained when comparing bicarbonate dialysis and AFB in elderly patients in whom there has been a drop in hypotension during the treatment by 13.8%% and a decline in the intolerance to therapy by 66%% ((Movilli et al., [1996])).

Figure 1. Comparison of frequency distribution of collapses in dialysis in two groups of critical patients in bicarbonate dialysis ((straight line//squares)) and acetate free biofiltration, AFB ((dotted line//triangles)): p < 0.001GLM for repeated measures ((Verzetti et al., [1998])).

Staring from these results there have been attempts to go back to the causes that determine such an improvement by identifying, amongst other things, the nitric oxide synthesis generated by the acetate present in the bath ((even if in moderate doses)) in bicarbonate dialysis. Indeed, the increase in the nitric oxide level compared to the basal values ((0.028 pmol//min)) has proven to be negligible in AFB, while it is equal to 2 pmol//min in bicarbonate dialysis ((Amore et al., [1997])).

The recovery of the normal hydro–electrolytic balance is the result of the removal of the excess water and electrolytes. Although the goal is straightforward, the methods for achieving it can prove to be very complex in that it directly involves cardiovascular stability. A concrete help can occur by controlling the blood volume trend during the treatment by means of biofeedback systems ((HEMOCONTROL™, Hospal Bologna–Italy)) in such a way as to avoid the hypovolemic‐‐related hypotensions. Systems of this kind are today available on the dialysis machines. By means of the continuous reading of the blood volume trend, the machine can modify in real time the therapy parameters ((weight loss rate and bath conductivity)) so that the blood volume follows a pre‐‐set trajectory which is not critical for the patient. A multi input multi output controller is then used to regulate all the main tasks of the treatment, such as blood volume reduction, total weight loss and equivalent conductivity.

The complexity of the blood volume control is thus referred back to the equipment while the physician's task is to determine the correct goals in terms of the patient's hemodynamic status.

The results of a multicentre study over 1,500 dialysis patients show a 30%% reduction in the number of hypotensive episodes. Moreover, the data stratified according to the critical degree of the patients have also shown ((Figure 2)) that the hypotension reduction reaches 70%% in patients who are particularly critical from the standpoint of cardiovascular stability ((Santoro et al., [1998])).

Figure 2. Comparison between bicarbonate dialysis, BD ((grey)), and BD with blood volume tracking ((black)) ((Santoro et al., [1998])).

Conclusions

Although the dialytic population is constantly increasing and the available resources remain virtually unchanged, it is necessary to assure the opportunity to enter into treatment for all. Thus, it is necessary to rationalise the resources bearing in mind that the costs of the facilities today account for about 70%% of the cost of treatment.

Containment of the social costs must come about in two directions: by optimising the process of service delivery and by reducing the induced costs relating to the long‐‐term morbidity of the technique ((non‐‐routine instrumental tests, surgical operations, hospital admissions and days of hospitalisation)), in other words, improving the quality of the treatments. So far there has been no proper quantification of the costs induced in relation to the kind of treatment administered. Thus a European multicentre trial has been started with the aim of evaluating the long‐‐term ((3 years)) effects of AFB in comparison with bicarbonate dialysis.

Uncited References

Lopot et al., [1996]

Santoro and Mancini, [1997]