Infusion therapy is an important component of many diseases treatment – and one of the main methods of intensive care for intensive care patients. Active infusion therapy using different infusion media, large volumes and high rates of intravenous fluid is especially relevant in critical patients, the most severe of which remains patients with septic shock. For more than two centuries of clinical use, infusion therapy has gone through a long evolutionary path and has become more effective and safer. However, like any drug, infusion therapy (in general and specific infusion media) has a number of side effects, especially when used excessively. Therefore, in recent years, the use of infusion therapy is considered as the appointment of any drug, taking into account indications, contraindications, methods of administration, dosing, duration, deescalation. This made it possible to identify the main stages of infusion therapy of critical conditions and shock: intensive infusion therapy (rapid administration of a large fluid volume), optimization of infusion therapy (reduction of the rate and volume of infusion), stabilization of the patient and minimization of infusion, de-resuscitation – removal of excess fluid from the body. With the development of clinical pathophysiology, the basic concepts of maintaining fluid homeostasis of the body in normal and critical conditions were revised, and the negative effects of infusion therapy at all stages of its use were studied. Therefore, in the intensive care of shock, the main clinical questions are: when to start fluid therapy, when to stop active fluid therapy, when to start fluid removal from the body, and when to stop fluid de-resuscitation. Thus, in order to implement the principle of personalized treatment, it is important to determine not only the «tolerance» of infusion therapy, but also the «sensitivity» to the infusion of a particular patient – the ability to maintain hemodynamics without the risk of fluid overload. Evaluation of routine clinical, instrumental and laboratory indicators of the state of macro- and microcirculation does not provide an opportunity to accurately answer these questions. Modern sonographic methods for monitoring central and peripheral cardiohemodynamics, ‘venous excess’ using Doppler and extended focus echocardiography allow us to assess the ‘tolerance of infusion therapy’. The implementation of this new direction will increase the efficiency and safety of infusion therapy and improve the outcomes of the critically ill patients’ treatment.