Ultra-low-tidal-volume ventilation during cardiopulmonary resuscitation in a pig model

该项目旨在评价猪心肺复苏过程中新建立的通气方法（超低潮气量通气，ULTVV）。在一项成功的初步研究显示ULTVV在复苏期间和自主循环恢复（ROSC）后的神经和肺保护作用以及与标准通气（IPPV）相比诱导室颤后的ROSC率普遍增加后，本试验旨在研究先前感知的有益影响是否在长期，更准确地说，将在两种通气策略（ULTVV与IPPV）之间比较两种不同的停搏时间（5与10分钟）。在预定义的、基于指南的复苏周期（约25分钟）后达到ROSC的动物-无论其属于哪个组-将被监测和处理24小时。在此期间，定期采集血液样本，不断监测和保存扩展的心血管测量结果，并详细评估肺功能。在监测期结束时，收获肺、脑和肾，准备进行组织病理学和分子生物学检测，并筛选潜在的机械或缺氧组织损伤。本实验旨在证实先前获得的结果，即复苏期间潮气量高度降低的通气可与增加的ROSC率以及较低的机械诱导的肺损伤和改善的肺功能有关。此外，长期试验旨在支持神经炎症减少的迹象，这些迹象在8小时后突出，但可能不会持续更长时间。增加的停搏时间修改为更长的值提供了临床上更现实的设置，并结合延长的监测期可能有助于阐明ULTVV的积极作用是否持续以及以何种方式持续，或者它们是否随着更长的复苏周期而耗尽。预期的结果和见解计划成为新通气策略的可能临床研究的基础，并可能最终为患者创造一种潜在的新疗法。

The proposed project deals with the evaluation of a newly established ventilation method (ultra-low-tidal-volume ventilation, ULTVV) during cardiopulmonary resuscitation in a porcine model. Following a successful pilot study showing neuro- and lung-protective effects of ULTVV during resuscitation and after return of spontaneous circulation (ROSC) and generally increased ROSC-rates after induced ventricular fibrillation compared to standard ventilation (IPPV), the presented trial aims to investigate whether or not the previously perceived beneficial influences persist in a prolonged, clinically more accurate setting with longer arrest and monitoring periods.More precisely, two different arrest periods (5 vs. 10 minutes) will be compared between two ventilation strategies (ULTVV vs. IPPV). Animals that reach ROSC after a predefined, guideline-based resuscitaion cycle (~25 minutes) -regardless to which group they belong - will be monitored and treated for 24 hours. During this period blood samples are taken regularly, extended cardiovascular measurements are monitored and saved constantly and pulmonary function is assessed in detail. At the end of the monitoring period, lungs, brain and kidneys are harvested, prepared for histopathologic and molecularbiologic testing and are screened for potential mechanical or hypoxic tissue damages.This experiment aims at confirming previously obtained results that ventilation with highly decreased tidal volumes during resuscitation can be linked to increased ROSC rates as well as lower mechanically induced lung damage and ameliorated pulmonary function. Additionally, the long term trials are designed to support signs of decreased neuroinflammation, which were prominent after 8 h but might not persist over a longer period. The added arrest time modification to longer values provides a clinically more realistic setting and combined with the prolonged monitoring period might help to elucidate, if and in what fashion the positive effects of ULTVV persist or if they exhaust with longer resuscitation cycles. The expected results and insights are planned to be the basis of possible clinical studies for the new ventilation strategy and might eventually create a potential new therapy for patients.