Circulatory Compromise:Opportunities to improve outcome

描述(由申请人提供)： 创伤方案：失血性休克是创伤后死亡的主要原因。辅助正压通气(PPV)对低血容量患者心输出量的不利影响一直被低估。PPV尚未被认为是预后中的一个负混杂变量。最近对严重出血的研究表明，较低的通气率显著改善了血流灌注和存活率。具有讽刺意味的是，急救人员仍在接受培训，以便在低血压创伤患者中使用高比率的PPV。我们的中心假设：医院前常用的辅助通气率对创伤后低血压患者的死亡率和神经预后有不利影响，使用较低的通气率，如每分钟6次呼吸将显著改善预后。具体目的：确定当急救护理人员提供受控的PPV时，与目前不控制PPV的做法相比，创伤后低血压患者的存活率和神经结局显著改善。此外，使用6/分钟的受控通风率比12/分钟的通风率获得了进一步的改善。心脏骤停方案：即使接受了标准的手动CPR技术，大多数在院外心脏骤停的患者仍然在到达医院之前死亡。许多因素导致了这些糟糕的存活率统计数据，包括CPR技术本身的低效。CPR仅提供正常心肌灌注的10%至20%，即使在早期进行也只提供生理正常脑灌注的20%至30%。在这项建议中，我们选择了我们认为最有希望改善CPR效率、患者存活率和心脏骤停后神经预后的方法。这种方法是主动按压减压(ACD)CPR和阻抗阈值装置(ITD)的结合，这是一种称为ACD+ITD CPR的技术，它在CPR减压阶段增强了重要器官的血流灌注。具体目的：确定与标准的闭胸式CPR相比，ACD+ITD CPR是否能改善院外心脏骤停(主要终点)成人患者出院后的存活率和神经预后。

DESCRIPTION (provided by applicant): Trauma Protocol: Hemorrhagic shock is a dominant cause of death after trauma. The detrimental effects of assisted positive pressure ventilation (PPV) on cardiac output in hypovolemic patients has been under-appreciated. PPV has not been recognized as a negative confounding variable in outcome. Recent studies of severe hemorrhage show that perfusion and survival are significantly improved with lower ventilatory rates. Ironically, emergency care personnel are still being trained to use high rates of PPV in hypotensive trauma patients. Our central hypothesis: assisted ventilation rates commonly used in the pre.hospital setting adversely affect mortality and neurological outcome in patients with post-traumatic hypotension and that using a lower ventilation rate such as 6 breaths per minute will improve outcome significantly. Specific Aims: To establish that survival and neurological outcome are significantly improved in cases of post-traumatic hypotension when emergency care providers deliver controlled rates of PPV as compared with the current practice of uncontrolled rates of PPV. In addition, further improvements are gained using controlled ventilation rates of 6/minute compared with 12/minute. Cardiac arrest protocol: Even when receiving standard, manual CPR techniques, most patients who have out-of-hospital cardiac arrest still die prior to arriving at a hospital. Many factors contribute to these poor survival statistics, including the inefficiency of the CPR technique itself. CPR provides only 10% to 20% of normal myocardial perfusion, and only 20% to 30% of physiologically normal cerebral perfusion even when performed early. In this proposal, we have selected what we believe is the most promising approach to improving CPR efficiency, patient survival, and neurological outcome following cardiac arrest. This approach is the combination of active compression-decompression (ACD) CPR and the impedance threshold device (ITD), a technique termed ACD+ITD CPR, which enhances vital organ perfusion during the decompression phase of CPR. Specific aim: To determine whether ACD+ITD CPR will improve survival to hospital discharge and neurological outcome after witnessed, out-of-hospital cardiac arrest in adults (primary endpoint) when compared with standard closed chest CPR.