Neonatal Pulmonary Physiology
Importance: The importance of this chapter on pulmonary physiology is that it provides the reader with an understanding of normal and abnormal lung mechanics, lung volumes, and gas movement during each breath. In addition, the chapter provides an understanding of the elements of pulmonary gas exchange and how those elements can be altered by conditions in the neonate, with and without co existing pulmonary disease. Objective: To make complex physiological issues relevant to practicing neonatal physicians and other clinicians. Design: The chapter is divided between an explanation of lung mechanics and pulmonary gas exchange, with the effort of linking these two topics when possible. Conclusion: Knowledge of the functional components of lung volume and the mechanical properties of the lungs plays an important role in the understanding of neonatal respiratory physiology. The lungs have physical and mechanical properties including elastic recoil, airway resistance and inertance that resist inflation. The dynamic interactions between these properties are responsible for the effort required during normal spontaneous tidal breathing. The movement of oxygen from ambient air to alveolar air to blood to tissue and the reverse movement of carbon dioxide from tissue to lung to the exhaled gas cannot stop or be profoundly impaired for more than a few minutes before death ensues. Even in healthy infants, the lungs function as multiple discrete gas exchanging units. Subdividing of lung areas becomes particularly problematic when the adverse impacts of preterm birth are superimposed.
Avery's Diseases of the Newborn
Functional residual capacity (FRC) Respiratory system compliance and resistance; Newborn pulmonary mechanics measurements; Pulmonary gas exchange; Ventilation perfusion ratios
Truog WE, Manimtim WM. Neonatal pulmonary physiology. Avery’s Diseases of the Newborn (11th Ed). Published online 2024:548-558. doi:10.1016/b978-0-323-82823-9.00039-8