The pathophysiological characteristics of shock can be divided into three stages, which are early, middle and late stages of shock. In the early stage of shock, due to the related neurohumoral regulatory mechanism, the peripheral vasculature shows a contracted state, and the microvasculature shows a “less perfusion and less flow” characteristic with less perfusion and less outflow during this period. With the progress of shock, the accumulation of a large number of acidic metabolites and the formation of microthrombi will often cause the pre-capillary sphincter diastole and increase the posterior resistance of microcirculation, which will form the microcirculatory characteristics of “more perfusion and less flow”. If the shock is not corrected, plasma extravasation and blood concentration will further aggravate the ischemia and hypoxia of tissue cells, and further decrease the amount of cardiac blood return and cardiac output, resulting in a decrease in effective circulating blood volume. This eventually leads to the degeneration and necrosis of tissue cells, causing the microcirculation to be almost completely filled with microthrombi, and eventually forming the irreversible late stage of shock, also called the DIC stage, during which the microcirculation is characterized by “no flow and no perfusion”.