Restoring microcirculation in anesthesia: Impact, usefulness and controversies

Abstract

Mentioning microcirculation and endothelial dysfunction to explain the pathophysiology of diseases whose relationship was not well understood is a recent phenomenon. Microcirculation is not only compromised by disease but can be altered by conditions that the anesthesiologist faces (agents and anesthetic techniques). There is significant and increasing evidence that anesthetic agents may alter it. The importance? In a state of hypoperfusion, it can be worsened by other factors (mechanical ventilation, vasoactive medications, sedatives, opioids). In shock's late stage, the support to tissue perfusion given by peripheral circulation is weak and disappears. Therefore, is it beneficial to direct targeted therapies only toward macrovascular goals? Methods for identifying early alteration and direct therapies for restoration are important. The clinical evaluation is rapid and reproducible, and measuring body temperature determines alteration indirectly. There are other methods to determine microcirculation objectively: nowadays, optical evaluation techniques using polarized orthogonal spectral light and sidestream dark-field are the best approach. In hemorrhagic shock the degree of organ dysfunction is determined by microvasculature's alteration. Compensatory mechanisms exist for this purpose, making its measurement and use in perioperative period important. Strategies have been studied to improve tissue perfusion (recruitment of microcirculation). The recentness of the study of microcirculation calls its usefulness into question. It is necessary to determine the clinical impact through controlled clinical trials with protocols on resuscitation strategy, which can complement the current perioperative anesthetic practice.