Identification of cerebral perfusion targets during extracorporeal resuscitation

尽管不断努力优化复苏患者的护理，但平均只有8%的患者在院外复苏后存活并可以活着出院。大量的这些复苏患者在成功复苏的情况下也表现出持续的神经功能障碍。各种研究已经证明，在使用胸外按压的常规心肺复苏期间仅实现不足的脑血流量。为了改善心脏骤停后的再灌注，近年来越来越多地使用体外泵系统进行复苏（称为eCPR）。在选定的患者中，eCPR与传统复苏相比的优越性已经得到证实。然而，eCPR仍然是一种基本上不确定的治疗方法。虽然传统复苏有明确的建议，但eCPR仍然没有建议或目标标准。由于缺乏治疗建议，在临床实践中经常针对不同的再灌注流量。复苏导致的神经损伤包括缺血成分和再灌注成分。已知在全脑缺血后或心脏骤停后的再灌注期间，可以观察到即使恢复了具有生理血流的体循环也不显示灌注的脑区域。这种现象被称为无复流现象。迄今为止，这种现象的确切病理机制仍不清楚。过去，一方面讨论了待灌注组织的变化，另一方面讨论了灌注血液的变化。在我们的弗赖堡猪复苏模型中，我们现在首次成功地证明了使用具有高体外流量的体外循环系统（ECC）的无复流现象的可逆性。回流现象提出了高再灌注流量或甚至已知的体外循环副作用对无回流现象的影响程度的问题。本研究将探讨这一点，我们的模型为研究无复流现象的机制提供了可能，同时也为ECC在复苏中的临床应用提供了信息。

Despite continuous efforts to optimize the care of resuscitation patients, on average only 8% of all patients survive out-of-hospital resuscitation and can be discharged from the hospital alive. A large number of these resuscitation patients also exhibit persistent neurological functional impairments in the event of successful resuscitation. Various studies have already demonstrated that only insufficient cerebral blood flows are achieved during conventional cardiopulmonary resuscitation using chest compressions. These insufficient flows contribute to the aggravation of reperfusion injury after ischemia.To improve reperfusion after cardiac arrest, extracorporeal pump systems have been increasingly used in resuscitation in recent years (called eCPR).In selected patients, superiority of eCPR compared to conventional resuscitation has already been demonstrated. However, eCPR remains a largely undefined therapeutic approach. While there are clear recommendations for conventional resuscitation, there are still no recommendations or target criteria for eCPR. Due to this lack of therapeutic recommendations, different reperfusion flows are often targeted in clinical practice.The neurological damage resulting from resuscitation consists of an ischemia component as well as a reperfusion component. It is known that during reperfusion after global cerebral ischemia or after cardiac arrest, cerebral areas can be observed that do not show perfusion even despite restoration of a systemic circulation with physiological blood flows. This phenomenon is called the no-reflow phenomenon. To date, the exact pathomechanism of this phenomenon remains unclear. In the past, changes of the to be perfused tissue on the one hand and changes of the perfusing blood on the other hand have been discussed.In our Freiburg porcine resuscitation model, we have now for the first time succeeded in demonstrating a reversibility of the no-reflow phenomenon using an extracorporeal circulation system (ECC) with high extracorporeal flows.This reversibility of the no-reflow phenomenon raises the question of the extent to which a high reperfusion flow or even known side effects of extracorporeal circulation influence the no-reflow phenomenon. This will be investigated in this project.Our model offers the possibility to investigate the mechanism of the no-reflow phenomenon and to collect information for the clinical use of ECCs in resuscitation at the same time.