Which law explains the phenomenon of atelectasis in ARDS patients?

The phenomenon of atelectasis in patients with Acute Respiratory Distress Syndrome (ARDS) is best explained by Laplace's Law. This law describes the relationship between the pressure inside a spherical structure and the surface tension of the fluid lining that structure. In the context of the lungs, alveoli can be considered as small spheres.

According to Laplace's Law, the pressure required to keep the alveoli open is directly proportional to the surface tension and inversely proportional to the radius of the alveoli. In ARDS, the alveoli often become filled with fluid and inflammatory cells, increasing surface tension and making it more difficult for the alveoli to remain open. Smaller alveoli require higher pressure to stay inflated, which can lead to atelectasis if the pressure is not sufficient, as they collapse when the surface tension overcomes the ability of the surrounding air to keep them expanded.

Understanding this law is critical in comprehending how surfactant deficiency affects lung mechanics and contributes to atelectasis in ARDS patients. This aspect highlights the importance of surfactants in reducing surface tension and maintaining alveolar stability, which can inform treatment approaches.

The other options relate to different physical principles: Boyle's Law pertains to the relationship between pressure and volume