Pulmonary gas exchange

Pulmonary gas exchange is the fundamental physiological process responsible for the uptake of oxygen from the external environment and the simultaneous elimination of carbon dioxide from the bloodstream. This exchange occurs at the alveolar-capillary interface within the lungs, where gases move across thin epithelial and endothelial membranes via passive diffusion driven by partial pressure gradients (StatPearls, 2023). Effective gas exchange is essential for aerobic metabolism, cellular respiration, and the maintenance of the body's acid-base balance. Disruptions in this process, often caused by ventilation-perfusion (V/Q) mismatching, diffusion limitations, or shunting, are central to the pathophysiology of various respiratory conditions (NIH, 2022). Clinical impairment of pulmonary gas exchange is a hallmark of diseases such as Chronic Obstructive Pulmonary Disease (COPD), Acute Respiratory Distress Syndrome (ARDS), and interstitial lung diseases. While pulmonary gas exchange is a physiological outcome rather than a single molecular target, it serves as the primary therapeutic objective for many pharmacological interventions. Drugs such as bronchodilators, pulmonary vasodilators, and exogenous surfactants are utilized to optimize the components of gas exchange by improving airflow, matching blood flow to ventilated alveoli, or reducing surface tension to prevent alveolar collapse (PubMed, 2021).

Other names

Alveolar gas exchangeExternal respirationGas exchangePulmonary respiration

Optimization of gas diffusion through bronchodilation, reduction of alveolar surface tension, or modulation of pulmonary vascular resistance to improve ventilation-perfusion matching.