Extravasation of body fluids is a typical symptom of CLS, which is a common complication during the treatment of patients with severe trauma and shock, and is essentially a process of redistribution of body fluids with the development of shock. It is very important to take appropriate treatment during this process to maintain the stability of the body’s major organ functions. The therapeutic goals of CLS are to prevent and treat CLS, restore normal blood volume, improve circulatory function, and maintain adequate oxygen supply. In order to achieve this goal, the following preventive measures are needed. 1, active prevention of primary diseases The most effective way to prevent CLS is to eliminate the causes of CLS, actively treat primary diseases, reduce the production of inflammatory mediators, and prevent capillary leakage. In critically ill patients, sepsis and SIRS are the most common causes of capillary leakage, so effective treatment is needed to address the causes of sepsis and SIRS. 2. Fluid therapy The purpose of fluid therapy is to restore blood volume, improve hemodynamics, and ensure organ perfusion. During the exacerbation period, due to the increase of capillary permeability, plasma infiltration from blood vessels to tissue interstitial space, tissue interstitial edema is obvious, blood pressure and central venous pressure are reduced, and blood is concentrated. In order to ensure the effective circulating blood volume and ensure the perfusion of important organs, fluid should be replenished under the condition of close monitoring of hemodynamics, with artificial colloid as the main supplement. However, the amount of rehydration should be controlled under the premise of ensuring circulation, because excessive rehydration can aggravate interstitial edema, cellular edema and pulmonary edema of tissues, affecting gas exchange of lungs and oxygen supply of tissue cells; at the same time, increased exudation from pericardium, thoracic and abdominal cavities, etc. also aggravates the damage of organ function. However, when capillary permeability improves and plasma leakage into the tissue interstitial space decreases during the recovery period, while a large amount of fluid leaks back into the capillary space from the tissue interstitial space and the effective circulating blood volume increases, pulmonary edema should be alerted, blood pressure and central venous pressure should be monitored, and fluid rehydration should be restricted and appropriate diuresis should be performed to reduce pulmonary edema. 3.Increase plasma colloid osmotic concentration In order to maintain the effective circulating blood volume in CLS, blood volume is restored after giving rehydration, but tissue edema becomes more serious and further affects organ function. Therefore, whether to give crystals or colloids for fluid therapy in capillary leakage has long been under close attention and also controversial. 4.Improve capillary permeability Methylprednisolone 80mg at 12 hours interval. 5.Ensure tissue oxygenation CLS in the lung shows a pathological process similar to ARDS, both of which are interstitial edema and decreased lung compliance caused by increased capillary permeability, and a higher concentration of inhaled oxygen should be used to ensure tissue oxygenation. If severe hypoxemia occurs, mechanical ventilation is feasible to avoid organ failure induced by hypoxia in tissues and organs. The mechanical ventilation strategy is consistent with that in ARDS, increasing positive end-expiratory pressure and prolonging inspiratory time. 6. Anti-inflammatory mediators Activated protein C (APC) is an endogenous anticoagulant substance with the efficacy of anti-inflammatory response and anti-coagulant activity, which can reduce capillary leakage in sepsis with definite efficacy. In addition, anti-inflammatory mediator therapy with IL-l receptor antagonists, platelet-activating factor antagonists, and prostacyclin inhibitors are still in the research stage and are not widely used in clinical practice.