%0 Journal Article
%T Blood flow maintenance by cardiac massage during cardiopulmonary resuscitation: Classical theories, newer hypotheses, and clinical utility of mechanical devices
%A Armando Sarti
%A Carlo Bartolozzi
%A Piercarlo Ballo
%A Simone Cipani
%J Journal of the Intensive Care Society
%D 2019
%R 10.1177/1751143718778486
%X 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 ˇ°cardiac pumpˇ±, which assumes that blood flow is driven by direct cardiac compression and the ˇ°chest pumpˇ±, which hypothesizes that blood flow is caused by changes in intrathoracic pressure. Newer hypotheses including the ˇ°atrial pumpˇ±, the ˇ°lung pumpˇ±, and the ˇ°respiratory pumpˇ± 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
%K Cardiopulmonary resuscitation
%K cardiac arrest
%K cardiac pump theory
%K thoracic pump theory
%U https://journals.sagepub.com/doi/full/10.1177/1751143718778486