What does Positive End-Expiratory Pressure (PEEP) do?

Positive End-Expiratory Pressure (PEEP) is a mode of mechanical ventilation that plays a critical role in maintaining alveolar stability. By maintaining a certain level of pressure in the airways at the end of expiration, PEEP helps prevent the collapse of alveoli. This is particularly important in conditions where alveoli can become collapsed or filled with fluid, such as in pneumonia or acute respiratory distress syndrome (ARDS).

By preventing the collapse of these small air sacs, PEEP enhances gas exchange and improves oxygenation. This is because alveoli that remain open can participate in the exchange of oxygen and carbon dioxide more effectively, reducing minute ventilation requirements and the work of breathing.

The other options do not accurately reflect the primary functions of PEEP. While PEEP does not directly increase the volume of air inhaled during each breath, it can contribute to improved oxygenation by ensuring more alveoli are available for gas exchange. PEEP does not influence heart rate as part of its function, nor is it primarily utilized for diagnosing respiratory diseases. Its main purpose is therapeutic, aiming to improve lung mechanics and gas exchange by maintaining airway pressure at the end of expiration, thereby facilitating better overall respiratory function.