ExtraCorporeal Membrane Oxygenation in the Therapy for REfractory Septic Shock With Cardiac Function Under Estimated

Inclusion Criteria: * Age between 18 and 75 years. * Patients admitted into ICU and diagnosed as septic shock (sepsis-3.0)13, after adequate fluid resuscitation, high-dose vasoactive drug application \[vasoactive inotropic score (VIS) \> 120\] and conventional therapy together with at least one of the following criteria: (1) sustained hypotension \[mean arterial pressure (MAP) \< 65 mmHg\]; (2) persistent lactacemia (two consecutive values \> 5 mmol/L with at least 30 min interval between samples), with non-decreasing trend on steady doses of inotropes and/or vasopressors; (3) persistent low mixed venous blood oxygen saturation (SvO2) (two consecutive values \< 55% with at least 30 min interval between samples), with non-increasing trend on steady doses of inotropes and/or vasopressors. The above condition lasts more than 5 hours. * Rapidly deteriorating sepsis-induced myocardial impairment is defined by at least one of the following criteria: (1) rapidly deteriorating ventricular function (LVEF \< 35%); (2) cardiac index (CI) \< 2L/min/m2 (\> 3 hr); (3) emerging refractory arrhythmia. * Informed consent provided by the patient or person with decisional responsibility. Exclusion Criteria: * Cardiac dysfunction caused by other causes is excluded, such as acute myocardial infarction, chronic heart failure, congenital cardiac disease, myocardial effusion, moderate to severe aortic regurgitation, severe aortic coarctation and so on. * High suspicion of pulmonary embolism, tension pneumothorax or cardiac tamponade as a cause of shock. * Prolonged cardiac arrest (\> 30 min) before ECMO, or CPR survivors remaining comatose. * Irreversible condition or meet the inclusion criteria for more than 12 hr. * Presence of active bleeding or anticoagulant contraindications. * Peripheral artery disease disabling insertion of outflow cannula to femoral artery. * Irreversible neurological pathology * Severe underlying condition with lift expectancy less than 1 year. * Special population, such as pregnancy, acquired immune deficiency syndrome (AIDS). * Patient included in another interventional clinical trial.