Final answer:
PEEP assists in preventing air spaces from collapsing during exhalation and contributes to stable lung inflation by maintaining open alveoli, thus enhancing gas exchange and oxygenation within the lungs.
Step-by-step explanation:
Positive End-Expiratory Pressure (PEEP) is a respiratory therapy concept used particularly in mechanical ventilation to maintain adequate oxygenation and lung volume. PEEP helps to prevent air spaces from collapsing during exhalation, which is essential for proper gas exchange in the lungs.
During expiration, the natural elasticity of the lung tissue causes it to recoil, increasing intrapulmonary pressure and expelling air. However, the surface tension within the alveoli opposes their expansion and could lead to collapse, a tendency that is counteracted by the presence of pulmonary surfactant which reduces surface tension. A key component of lung mechanics is lung compliance, the capacity of the lungs to stretch. Higher lung compliance means a greater potential lung volume, thereby reducing the air pressure within them during inspiration.
PEEP works by applying constant pressure to the airway during the expiratory phase of the breathing cycle, which helps to prop open the alveoli, ensuring they do not collapse and thereby protecting against atelectasis. By doing this, PEEP contributes to stable lung inflation, assisting in maintaining a higher functional residual capacity and improving oxygenation.