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báo cáo hóa học: " Microcirculatory alterations: potential mechanisms and implications for therapy"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Microcirculatory alterations: potential mechanisms and implications for therapy | De Backer et al. Annals of Intensive Care 2011 1 27 http www.annalsofintensivecare.eom content 1 1 27 Ù Annals of Intensive Care a SpringerOpen Journal REVIEW Open Access Microcirculatory alterations potential mechanisms and implications for therapy Daniel De Backer Katia Donadello Fabio Silvio Taccone Gustavo Ospina-Tascon Diamantino Salgado and Jean-Louis Vincent Abstract Multiple experimental and human trials have shown that microcirculatory alterations are frequent in sepsis. In this review we discuss the characteristics of these alterations the various mechanisms potentially involved and the implications for therapy. Sepsis-induced microvascular alterations are characterized by a decrease in capillary density with an increased number of stopped-flow and intermittent-flow capillaries in close vicinity to well-perfused capillaries. Accordingly the surface available for exchange is decreased but also is highly heterogeneous. Multiple mechanisms may contribute to these alterations including endothelial dysfunction impaired inter-cell communication altered glycocalyx adhesion and rolling of white blood cells and platelets and altered red blood cell deformability. Given the heterogeneous nature of these alterations and the mechanisms potentially involved classical hemodynamic interventions such as fluids red blood cell transfusions vasopressors and inotropic agents have only a limited impact and the microcirculatory changes often persist after resuscitation. Nevertheless fluids seem to improve the microcirculation in the early phase of sepsis and dobutamine also can improve the microcirculation although the magnitude of this effect varies considerably among patients. Finally maintaining a sufficient perfusion pressure seems to positively influence the microcirculation however which mean arterial pressure levels should be targeted remains controversial. Some trials using vasodilating agents especially nitroglycerin showed promising initial results but they were .