Post-cardiac arrest syndrome is one of the most common conditions that occurs in emergency departments after cardiac arrest when the patient has regained some voluntary circulation through cardiopulmonary resuscitation. This syndrome includes brain damage, such as pathological and physiological changes that occur after cardiac arrest because of cerebrovascular ischemia. Myocardial damage occurs, and patients who are hemodynamically unstable after cardiopulmonary resuscitation after a cardiac arrest can experience varying degrees of myocardial injury. Systemic ischemia-reperfusion injury occurs. After cardiopulmonary resuscitation, chest compressions can only address the blood supply to the heart, because of myocardial insufficiency, hemodynamic instability, and impaired microcirculation, so reperfusion injury occurs.