Microcirculatory alterations and dysfunction in sepsis

Sepsis is fundamentally a microcirculatory disease in which microvascular failure is the final common pathway leading to multiple organ dysfunction. A major challenge in clinical management is “macro–microcirculatory decoupling,” in which microvascular dysfunction persists despite normalized systemic hemodynamics. This review outlines the mechanisms underlying microcirculatory dysfunction, emphasizing endothelial glycocalyx degradation and perfusion heterogeneity. It also evaluates bedside monitoring techniques, including capillary refill time, hand-held vital microscopy, and contrast-enhanced ultrasound, and examines key quantitative metrics, including the microvascular flow index and perfused boundary region. Incorporating these parameters into resuscitation protocols supports a transition to microcirculation-responsive therapy, optimizing tissue oxygenation while minimizing fluid overload. Finally, this review discusses the potential of artificial intelligence to standardize microcirculatory assessment and advance personalized, objective hemodynamic management.