Gazmuri R J, Weil M H, Tang W
Department of Medicine, University of Health Sciences, Chicago Medical School, Illinois 60064, USA.
Rev Med Chil. 1991 Nov;119(11):1301-10.
When immediate defibrillation fails, successful cardiac resuscitation is contingent on prompt reestablishment of myocardial blood flow. Conventional methods of closed-chest resuscitation generates only critical levels of myocardial blood flow and therefore are of limited value for successful resuscitation. Methods that optimize the site, depth, rate and duration of precordial compression may increase myocardial blood flow, however, the lack of objective measurements of their hemodynamic effects limits the optimal performance of this resuscitation method. With the recognition that elimination of CO2 is flow limited, measurement of end-expired PCO2 has emerged as a practical option for continuous assessment of systemic blood flow and coronary perfusion pressure. With measurement of the end-expired PCO2, operator fatigue may be recognized, the technique of precordial compression may be optimized, and the likelihood of restoring spontaneous circulation may be estimated. When conventional cardiac resuscitation fails or is predicted to fail by measurements of end-tidal PCO2, more effective interventions such as open-chest direct cardiac massage may be instituted. Regarding the vast resuscitation polypharmacy, only agents that act by selectively augmenting coronary perfusion pressure and myocardial blood flow are of proven benefit for successful resuscitation.
当即时除颤失败时，心脏复苏成功与否取决于能否迅速重建心肌血流。传统的闭胸复苏方法只能产生临界水平的心肌血流，因此对成功复苏的价值有限。优化胸前按压部位、深度、频率和持续时间的方法可能会增加心肌血流，然而，缺乏对其血流动力学效应的客观测量限制了这种复苏方法的最佳效果。认识到二氧化碳的排出受血流限制后，呼气末二氧化碳分压的测量已成为连续评估全身血流和冠状动脉灌注压的一种实用选择。通过测量呼气末二氧化碳分压，可以识别操作者的疲劳，优化胸前按压技术，并估计恢复自主循环的可能性。当传统的心脏复苏失败或根据呼气末二氧化碳分压测量预测会失败时，可以采取更有效的干预措施，如开胸直接心脏按摩。关于大量用于复苏的药物，只有通过选择性增加冠状动脉灌注压和心肌血流起作用的药物才被证明对成功复苏有益。
