Mechanical cardiopulmonary resuscitation for patients with cardiac arrest

Cardiopulmonary resuscitation (CPR), also called basic life support, is an emergency medical procedure performed to restore blood flow (circulation) and breathing. The goal of CPR is to provide oxygen quickly to the brain, heart, lungs, and other organs until normal function of the heart and lung is restored. CPR can help prevent brain damage and death in children. It is reported that approximately 600 000 individuals suffer from cardiac arrest and receive cardiopulmonary resuscitation in the United States and Europe each year. Although modern CPR substantially decreases the mortality induced by cardiac arrest, cardiac arrest still accounts for over 50% of deaths caused by cardiovascular diseases. he success rate of CPR ranging widely from 5% to 10% is based on many factors such as (1) causes of cardiac or respiratory arrest; (2) underlying health conditions of victims; (3) time elapse between arrest and CPR; and (4) techniques for CPR. The survival rate is affected not only by CPR but more importantly by its quality. Effective CPR can contribute more blood flow to the brain, heart and other organs, and thus increase the survival rate of patients with cardiac arrest. In November 2005 the AHA revised CPR guidelines to emphasize chest compression and its effect on blood pressure. Studies However, during CPR even with the best manual chest compressions, cardiac output is approximately 20% to 30% of normal value, and performer's fatigue may also reduce the quality of the compressions. Besides, chest compressions can not be performed during the transportation of patients, which prolong the time between the arrest and CPR, and also increase the diffi culty of resuscitation. Therefore, to avoid or reduce these negative factors and to improve the