Effect Of20Minutes Chest Compression By LUCAS On Porcine Coronary Arterial

Background and ObjectiveIt has been estimated that375,000people in Europe and275,000in the USA are victims of sudden cardiac arrest each year. The great majority occur out of hospital and the1-year survival rate remains extremely poor-less than5%.In China, the number of people who died of sudden cardiac arrest is increasing every year. Sudden cardiac arrest is often treated rapidly and successfully with cardiopulmonary resuscitation (CPR).For the patients that the initial resuscitation efforts are not immediately successful, extended periods of manual chest compressions are needed to maintain coronary and cerebral circulation. In patients who require prolonged CPR, mortality rates are very high. Several experimental studies have revealed that manual external cardiac massage results in, at best, a cardiac output of around20-30%of normal. Studies have revealed that the rescuer was unable to perform compressions for more than approximately1min before beginning to lose effectiveness, and after4min, they achieved only about30%of the chest compression deemed necessary. Furthermore, effective manual chest compressions are difficult to perform during transport of the patient. To achieve more efficient chest compressions, several mechanical devices have been available. Lund University Cardiopulmonary Assist System (LUCAS) is a new device providing automatic chest compression and active decompression. In experimental model on pigs, as well as the data from clinic, LUCAS-CPR produced significantly better circulation during sudden cardiac arrest. But no study about the effection on the coronary artery after LUCAS-CPR has been done yet. Therefore the objective of this study was to investigate the effect of chest compression by LUCAS on the function of coronary artery.Materials and MethodsPorcine coronary arterial endothelial function was studied in organ bath. Sixteen Swedish domestic pigs with a mean weight of32kg were randomized into two groups (8pigs in each). For the first group Chest compression was given by LUCAS (LUCAS-CPR) for20minutes before the hearts were harvested. For the second group(as fresh controls), the heart were harvested immediately after being anesthetized. Segments of the coronary arteries from all the hearts of16pigs were transferred to organ bath immediately. The thromboxane A2and substance P were used for contraction and relaxation of the segments.ResultCompared with fresh controls group’s maximal EDR (98±0.93)%,20minutes LUCAS-CPR group (96±0.94)%has no significant difference (p>0.05). The sensitivity of the Endothelium to substance P, expressed as the pEC50value also has no significant difference between two groups (p>0.05). The diameter of the segments when they achieved the maximal EDR which are1.31±0.15mm and1.27±0.19mm respectively has no significant difference between two groups.Conclusion20minutes LUCAS-CPR doesn’t significantly reduce the function of the coronary artery.