Pathogenesis of diffusion dysfunction

Many people are not particularly familiar with diffusion dysfunction, which refers to the entry of oxygen, carbon monoxide and other gases into the alveolar membrane, causing an obstructive symptom. It often leads to an imbalance in the ratio of air and blood flow in patients, causing hypoxia in patients. This is also quite harmful to patients. The amount of diffusion, diffusion time, molecular weight of the gas and gas partial pressure all have important relationships.

Pathogenesis of diffusion dysfunction

1. Decreased diffusion area: The diffusion area of ​​the alveolar membrane of a normal adult is about 80m2. At rest, the alveolar diffusion area is about 35m2 to 40m2. Because of its large reserve, ventilation dysfunction will only occur when it is reduced by more than half. Reduced alveolar membrane area can be seen in pulmonary consolidation, atelectasis, emphysema, and lobectomy.

The amount of diffusion depends on the difference in gas partial pressure on both sides of the membrane, the diffusion area, distance, time, gas molecular weight and its solubility in the diffusion medium. Emphysema and other lung tissue lesions, diffuse pulmonary interstitial fibrosis and other diseases can cause reduced diffusion function. Clinically, when lung lesions produce diffusion dysfunction, there is often a significant ventilation/perfusion imbalance, which results in hypoxia.