Физиологические основы целенаправленной инфузионной терапии в кардиохирургии (обзор)

Abstract

Goal-directed fluid therapy is a paradigm in perioperative medicine, which includes haemodynamic monitoring and individualized haemodynamic management in high-risk patients by means of fluid therapy. This approach has certain benefits compared with the traditional model of fluid therapy during the perioperative period of cardiac surgery. The required fluid volume can be hard to determine. Traditionally, fluid therapy was guided by static preload parameters, such as central venous pressure and pulmonary artery occlusion pressure, which failed to provide adequate precision. In opposition to static parameters, a number of dynamic indices and tests were developed to assess fluid responsiveness. The cornerstone of dynamic indices are cyclic preload changes due to intrathoracic pressure variations during mechanical ventilation. Dynamic tests are circulatory stress tests involving preload changes. The most frequently used tests are passive leg raise, fluid challenge test, and some others. However, in spite of their satisfactory predictive value, dynamic indices and tests have certain limitations, which must be taken into consideration. For instance, mechanical ventilation, sinus rhythm, intact thorax, and normal respiratory mechanics are obligatory conditions for applying dynamic indices. Thus, using dynamic indices can be difficult in cardiac surgery, making the search for new methods to overcome their limitations highly important.