Optimized Procedure to Evaluate the Thermal Energy Transfer in Hemodialysis Treatment

Hemodialysis treatment is biased by some complications during its operative phases. One of these potential accidents consists in intradialytic hypotension, that certainly causes discomfort to the patient but may even increase death risk. Therefore, it is very suitable, for reasons of prevention, predicting such events in the clinical routine procedures. As a cause of hypotension occurrence might be found in thermal energy/heat exchanges between extracorporeal system and the surrounding environment because of the operating temperatures during the clinical therapy. In the present work, a model for evaluating such heat losses is proposed and improved in order to maintain constant patient’s blood temperature as much as possible. By means of a deep investigation on these issues, the authors have defined a convenient procedure to improve and optimize the clinical treatment process. Differently from most of the hemodialysis machines used nowadays which control automatically the dialysate solution temperature starting from peripheral body temperature measurements, the proposed method is based on the control of only two important parameters: i) the pre-dialysis core temperature of the patient, and ii) the temperature of the blood entering the artery from the extracorporeal circuit after the treatment in the dialyzer. Measurements of arterial and venous blood temperatures are obtained in a non-invasive way by means of a suitable estimation of thermal energy exchanges between the blood and the environment during the extracorporeal recirculation. The suggested model guarantees a constant core temperature of the patient, improving prevention from intradialytic hypotension.