Success of the total hip arthroplasty depends on the measures that optimize perioperative conditions. They increase the emotional stress of the staff and error probability. It is planned to evaluate semi-closed loop infusion system, its adaption for infusion application's influence to near and far treatment outcomes done by prospective randomized clinical trial. This is done by performing total hip arthroplasty. It's expected to evaluate the semi-closed loop system's influence on the doctor's emotional tension during the decision making.