Fisiopatologia do desenvolvimento pulmonar

Abstract

The purpose of the present article is to summarise current thought on lung development seen as a dynamic process occurring before and after birth. The article is divided into 6 sections: morpho-functional basis; abnormalities of ventilation; abnormalities of perfusion; hyaline membrane disease; agenesis, aplasia and hypoplasia; and conclusions. In each section pulmonary pathophysiology is discussed based not only on its specific mechanisms but also on its effects on pulmonary development. The final conclusions are as follows: 1) In the first years of life, the human lung is a fragile organ, though ready to perform it respiratory role. 2) The structural immaturity that characterizes that period (since acinar development is postnatal) reduces the functional reserve of the lung to its minimum, allowing for any pathophysiological change to acutely affect respiration. 3) The child's lung is more prepared to respond to pathophysiological changes without acute respiratory effects; nevertheless, and until adult life, and disease can affect normal lung development by reducing acinar growth. 4) Modern techniques are creating a growing population of children whose lungs, though hypoplastic for a certain period, recover and grow afterwards in normal conditions. Very little is know about the structural and functional recover of these lungs.