Cipani Simone, Bartolozzi Carlo, Ballo Piercarlo, Sarti Armando
Department of Anaesthesia and Intensive Care, Santa Maria Nuova Hospital, Florence, Italy.
Department of Health Sciences, Anaesthesiology and Intensive Care Unit, University of Florence, Careggi Hospital, Florence, Italy.
J Intensive Care Soc. 2019 Feb;20(1):2-10. doi: 10.1177/1751143718778486. Epub 2018 Jun 18.
The mechanisms by which closed chest cardiac massage produces and maintains blood flow during cardiopulmonary resuscitation are still debated. To date, two main theories exist: the "cardiac pump", which assumes that blood flow is driven by direct cardiac compression and the "chest pump", which hypothesizes that blood flow is caused by changes in intrathoracic pressure. Newer hypotheses including the "atrial pump", the "lung pump", and the "respiratory pump" were also proposed. We reviewed studies supporting these different theories as well as the clinical evidences on the utility of mechanical devices proposed to optimize cardiopulmonary resuscitation, in view of their pathophysiological assumptions with regard to the underlying theory. On the basis of current evidence, a single theory is probably not sufficient to explain how cardiac massage produces blood flow. This suggests that different simultaneous mechanism might be involved. The relative importance of these mechanisms depends on several factors, including delay from collapse to starting of resuscitation, compression force and rate, body habitus, airway pressure, and presenting electrocardiogram. The complexity of the physiologic events occurring during cardiopulmonary resuscitation, together with the need of adequate training for a correct and prompt utilization of mechanical devices, might also partially explain the disappointing results of these devices in most clinical studies.
在心肺复苏过程中，胸外心脏按压产生并维持血流的机制仍存在争议。迄今为止，主要存在两种理论：“心泵”理论，该理论认为血流是由直接心脏按压驱动的；以及“胸泵”理论，该理论假设血流是由胸内压力变化引起的。还提出了包括“心房泵”“肺泵”和“呼吸泵”在内的更新的假说。鉴于这些机械装置在潜在理论方面的病理生理假设，我们回顾了支持这些不同理论的研究以及关于旨在优化心肺复苏的机械装置效用的临床证据。根据目前的证据，单一理论可能不足以解释心脏按压如何产生血流。这表明可能涉及不同的同时发生的机制。这些机制的相对重要性取决于几个因素，包括从心脏停搏到开始复苏的延迟、按压力度和频率、体型、气道压力以及呈现的心电图。心肺复苏过程中发生的生理事件的复杂性，以及正确、及时使用机械装置所需的充分培训，也可能部分解释了这些装置在大多数临床研究中令人失望的结果。
