Optimizing Chest Compressions for Bradycardia during Neonatal Resuscitation

摘要 出生窒息对全球健康造成巨大负担，每年导致100万新生儿死亡。 目前新生儿复苏计划(NRP)建议提供体外胸腔 在提供有效的外按压后新生儿心率保持在每分钟60次以下的按压 呼吸30秒。这份协议是基于专家的意见，而不是证据。这项提议的目的是 就是确定开始胸外按压的心率范围，以优化流向大脑的血液 还有心脏。新生儿出生时的低心率通常是由于气体交换受损，我们的初步研究 研究表明，在心脏还在跳动的情况下，进行胸外按压(CC)可能是有害的。 我们假设，持续的低心率(每分钟60英镑)的体外呼吸，以及药物，如 肾上腺素，只有在脉搏/心率减慢的情况下才会启动心脏外按压。这种方法 可以改善气体交换，导致更好的脑和心肌灌注，减少建立 心率达到每分钟≥100，减少脑部和心脏损伤。我们的具体目标将有助于确定 开始外按压时的最佳心率临界值(HR 60-40或40-20 bpm) 通过评估以下内容来定义羔羊模型： 1.气体交换和血液流向脑和心脏； 2.在进行胸外按压时失去固有心跳，并花费时间 达到理想的心率； 3.CC在脑和心脏损伤中的作用。 我们可以直接测量冠脉血流量，这是以前没有报道的，这将有助于建立 过渡期间流向心脏的正常和异常血流及其对体外循环的影响 压缩，这是一个新的观察结果。提出的研究对于找出当前的方法是否 提供新生儿复苏的可能性是可以改进的，这不是基于证据的。使用以下组合 血流动力学、生物标志物和成像技术，这些数据可以直接转化为新生儿 复苏。在产房使用心电图仪检测心率增加了 提供3倍的胸部按压，如果过度使用可能会造成更大的损害。也有可能是 早产儿心动过缓的复苏可能需要与足月妊娠不同的治疗方案。它是 了解当前做法所涉及的大脑和心脏损伤的风险非常重要。专注于 必要时提供体外呼吸和胸部按压，目的是限制心脏和窒息 在每年140万新生儿的复苏过程中，脑损伤将对全球产生重大影响。

ABSTRACT The result of birth asphyxia is a huge burden on global health contributing to 1 million neonatal death each year. The current recommendations by the neonatal resuscitation program (NRP) to provide external chest compressions when a newborn’s heart rate remains below 60 beats per minute after providing effective external breaths for 30 seconds. This protocol is based on expert opinion, but not evidence. The objective of this proposal is to determine the heart rate range for starting external chest compression to optimize blood flow to the brain and the heart. Low heart rate at birth in a newborn is normally due to impaired gas exchange, and our preliminary studies show that performing external chest compressions (CC) could be harmful when the heart is still beating. We hypothesize that continuing external breaths for low heart rate (<60 per minute), along with medications like epinephrine and only initiating external cardiac compressions if there is a loss of pulse/heart rate. This approach could improve gas exchange, leading to better cerebral and myocardial perfusion, reducing time to establish a heart rate of ≥ 100 per minute, and decrease brain and heart injury. Our specific aims will help determine the best heart rate cut-off (HR 60-40 or 40-20bpm) for initiating external compressions using both a preterm and term lamb model by evaluating: 1. Gas exchange and blood flows to brain and heart; 2. The loss of intrinsic heart beat when external chest compressions are performed and time taken to achieve the desired heart rate; 3. The role of CC on cerebral and cardiac injury. We can measure coronary blood flow directly which has not been reported before, which will help establish normal and abnormal blood flow to the heart during transition and the influence of performing external chest compressions, which is a novel observation. The proposed research is significant to find out, if the current method of providing neonatal resuscitation, which is not evidence based, could be improved. Using a combination of hemodynamics, biomarkers and imaging techniques, these data could be translated to direct neonatal resuscitation. Use of electrocardiogram in the delivery room to detect heart rate has increased the frequency of providing chest compressions by 3-fold, and may be causing more damage if over used. It is also possible that resuscitation in preterm bradycardia could require different treatment protocols than at term gestation. It is important to understand the risk of brain and cardiac damage involved with the current practice. Focusing on providing external breaths with chest compressions when needed, with the objective to limit cardiac and asphyxia brain injury will have a great impact globally during resuscitation of 1.4 million newborns each year.