Perioperative infusion support of surgical patients is the main and non-alternative element of treatment. At the same time, the tactics of infusion therapy continues to be the subject of study. Ideas about the optimal quantitative and qualitative composition of the fluid transfused to patients are being revised as ideas about the pathogenesis of critical conditions evolve. The basis of pathogenetic analysis of compensatory hemodynamic capabilities, as a point of application of infusion treatment, previously consisted mainly of invasive monitoring techniques, replaced in recent years by the control of routine parameters with proven high correlation with invasive ones. In current studies devoted to the problems of infusion correction of hemodynamic abnormalities, the most discussed issues are the applicability of isotonic and balanced polyionic crystalloids, less often colloidal solutions in various clinical situations, and the results of such studies do not always allow to unambiguously determine the choice of infusion media, and sometimes simply incomparable. Some researchers advocate the use of isotonic crystalloids, some works prove the best effectiveness of balanced salt solutions. With the volumes of treatment corresponding to the perioperative period, in most studies there are no differences in the effectiveness of the main composite groups of crystalloids at all. We see the reason for this in the peculiarities of randomization methods, when statistical limitations do not allow us to avoid discrete data analysis: their comparative grouping occurs according to the principle of selecting a target parameter, and all the others are classified as auxiliary or secondary. It seems to us that the involvement of arrays of data obtained in real clinical practice as a result of a combination of local theoretical and empirical ideas about corrective treatment regimens correlated with their effectiveness could smooth out the inconsistency of the results of such studies, especially since clinicians have a sample with a volemic load at their disposal, allowing them to predict the hemodynamic reaction of the patient's body to infusion and a set of routine parameters for more fine-tuning of therapy.