[Dialysis treatment: an unfulfilled promise]

In the last 50 years, the morbidity and mortality of patients on maintenance dialysis treatment has remained unacceptably high. This is because insufficient attention is paid to the main task of the kidneys: body fluid volume regulation. While nobody denies these basic physiologic principles, several developments have contributed to their neglect. First, a tendency towards short dialysis sessions and even more unfortunately the emphasis of opinion leaders on removal of urea, the least toxic of the metabolites. The necessity of severe dietary salt restriction is insufficiently stressed. Thus most patients remain slightly volume expanded, causing not only hypertension, but also dilatation of the heart. This leads to cardiovascular damage and even pulmonary oedema ('heart failure'), an entirely preventable complication. While several authors have shown better results by applying these principles, the focus on randomised controlled trials, which are practically unfeasible in this setting, still precludes their general acceptance.