Diedericks C, Crossley K J, Davies I M, Blank D A, Cramer S J E, Wallace M J, Te Pas A B, Kitchen M J, Hooper S B
The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.
FASEB J. 2025 Oct 15;39(19):e71064. doi: 10.1096/fj.202502372R.
The chest wall significantly impacts respiratory function after birth, but its role in the newborn remains poorly understood as it is structurally and functionally different from adults. In neonates, the chest wall is highly compliant, which allows it to expand to accommodate the incoming air and the lung liquid cleared into the pulmonary interstitium during lung aeration. However, the high neonatal chest wall compliance predisposes it to distortion, which reduces breathing efficiency and necessitates respiratory muscle activation to stabilize it. This increases the work of breathing and, when combined with fewer fatigue-resistant Type I muscle fibers (slow twitch, high oxidative capacity) in the diaphragm muscle, the risk of respiratory fatigue is increased. Nevertheless, as the chest wall is highly compliant in the newborn, recent studies have demonstrated that extra-thoracic pressures can influence chest wall mechanics. Positive extra-thoracic pressures (such as those applied with tight swaddling) limit chest wall expansion, whereas a small constant negative extra-thoracic pressure stabilizes the chest wall and improves oxygenation in neonates. In this review, we aim to summarize the current evidence on chest wall function in fetuses and neonates, particularly during lung liquid clearance, lung aeration, and breathing after birth. Furthermore, we will explore how knowledge from newborn respiratory physiology may inform our understanding of the respiratory consequences of pulmonary oedema in adults, such as occurred during the initial stages of the COVID-19 pandemic.
出生后胸壁对呼吸功能有显著影响，但由于其在结构和功能上与成年人不同，其在新生儿中的作用仍知之甚少。在新生儿中，胸壁顺应性很高，这使其能够扩张以容纳吸入的空气以及在肺通气过程中清除到肺间质中的肺液。然而，新生儿胸壁的高顺应性使其容易变形，从而降低呼吸效率，并且需要呼吸肌激活来使其稳定。这增加了呼吸功，并且当与膈肌中抗疲劳的I型肌纤维（慢肌纤维，高氧化能力）较少相结合时，呼吸疲劳的风险就会增加。尽管如此，由于新生儿的胸壁顺应性很高，最近的研究表明胸外压力可以影响胸壁力学。正的胸外压力（如紧裹襁褓时施加的压力）会限制胸壁扩张，而小的恒定负胸外压力则能稳定胸壁并改善新生儿的氧合。在这篇综述中，我们旨在总结目前关于胎儿和新生儿胸壁功能的证据，特别是在肺液清除、肺通气和出生后呼吸过程中的证据。此外，我们将探讨新生儿呼吸生理学知识如何有助于我们理解成人肺水肿的呼吸后果，例如在新冠疫情初期所发生的情况。
