The role of technology in hemodialysis

The evolution of hemodialysis therapy has been characterized over the years by the search for reliable devices and supplies, for more efficient treatments and finally for a more tolerable therapy in long term dialysis patients. In this view, three steps can be identified: a) the first step was the creation of safe and reliable vascular access, dialyzers and machines. This step led to the birth of modern dialysis and treatment personalization was the logical consequence. Each patient is a single entity and he requires a specific therapy prescription and delivery. From this concept the search for adequacy and better outcomes has been generated, with the inevitable consequence that newer techniques were explored in the attempt to perform a more efficient and clinically tolerated dialysis therapy. b) The second step was the attempt to consider the intratreatment variations as possible source for dialytic morbidity. In this view, efforts were made to pre-set ultrafiltration and dialysate sodium profiles in the machine to counterbalance the negative effects of uncontrolled water and solute removal. However, this approach failed to provide significant results, because ultrafiltration and sodium profiles were predetermined and no adaptations could be made if the designed profile was inadequate. c) The third step in the evolution of dialysis was the understanding that on-line signals from the machine and from the patients were required in order to prepare and carry out the adequate response and variation of treatment parameters. For this reason a series of sensors have been developed including urea and blood volume sensors which are offering the most important signals from the patient. In this way, accurate responses could be made during treatment and from a simple manual feedback, we have today a completely automatic form of biofeedback. The question that now arises is where to find the financial resources to afford the upcoming technology. Another question is whether this new technology should be for everybody in routine dialysis or it should be designed for specific conditions. In other words, are these toys for nice experimental studies and speculations or are they tools to improve dialytic outcomes and morbidity? Probably, technology cannot be stopped in its evolution. What is exceptional today will probably be part of the routine of tomorrow. It seems that we are struggling more with the complex physiology of human body than with mechanical or electronic problems that certainly find their solution before or after. The increasing use of computers and the evolution of the applied software will certainly help in reducing the costs and improving the performances of our newer dialysis devices.