Monash Newborn, Monash Children's Hospital, Melbourne, Victoria, Australia;
Departments of Paediatrics and.
Pediatrics. 2021 Mar;147(3). doi: 10.1542/peds.2020-016972.
The transition from intrauterine life to extrauterine existence encompasses significant cardiorespiratory adaptations. These include rapid lung aeration and increase in pulmonary blood flow (PBF). Perinatal asphyxia and fetal growth restriction can severely hamper this transition. Hypoxia is the common denominator in these 2 disease states, with the former characterized by acute insult and the latter by utero-placental insufficiency and a chronic hypoxemic state. Both may manifest as hemodynamic instability. In this review, we emphasize the role of physiologic-based cord clamping in supplementing PBF during transition. The critical role of lung aeration in initiating pulmonary gas exchange and increasing PBF is discussed. Physiologic studies in animal models have enabled greater understanding of the mechanisms and effects of various therapies on transitional circulation. With data from sheep models, we elaborate instrumentation for monitoring of cardiovascular and pulmonary physiology and discuss the combined effect of chest compressions and adrenaline in improving transition at birth. Lastly, physiologic adaptation influencing management in human neonatal cohorts with respect to cardiac and vascular impairments in hypoxic-ischemic encephalopathy and growth restriction is discussed. Impairments in right ventricular function and vascular mechanics hold the key to prognostication and understanding of therapeutic rationale in these critically ill cohorts. The right ventricle and pulmonary circulation seem to be especially affected and may be explored as therapeutic targets. The role of comprehensive assessments using targeted neonatal echocardiography as a longitudinal, reliable, and easily accessible tool, enabling precision medicine facilitating physiologically appropriate treatment choices, is discussed.
从宫内生活到宫外生存的转变包括重要的心肺适应。这些适应包括快速肺部充气和肺血流量（PBF）的增加。围产期窒息和胎儿生长受限会严重阻碍这种转变。缺氧是这两种疾病状态的共同特征，前者以急性损伤为特征，后者以子宫胎盘功能不全和慢性低氧血症为特征。两者都可能表现为血流动力学不稳定。在这篇综述中，我们强调了基于生理的脐带夹闭在过渡期间补充 PBF 的作用。讨论了肺充气在启动肺气体交换和增加 PBF 中的关键作用。动物模型的生理研究使我们更好地理解了各种治疗方法对过渡循环的机制和影响。根据绵羊模型的数据，我们详细介绍了监测心血管和肺生理的仪器，并讨论了胸部按压和肾上腺素联合使用改善出生时过渡的效果。最后，讨论了与缺氧缺血性脑病和生长受限相关的心脏和血管损伤的人类新生儿队列的生理适应对管理的影响。右心室功能和血管力学的损伤是预后的关键，也是理解这些危重病儿治疗原理的关键。右心室和肺循环似乎受到特别影响，可能作为治疗靶点进行探索。使用靶向新生儿超声心动图进行全面评估作为一种纵向、可靠和易于获取的工具的作用，能够促进精准医疗，从而做出符合生理的治疗选择，这一点值得讨论。
