What is the role of PEEP in mechanical ventilation for ARDS?

PEEP, or Positive End-Expiratory Pressure, plays a crucial role in the mechanical ventilation of patients with Acute Respiratory Distress Syndrome (ARDS). Its primary function is to prevent alveolar collapse at the end of expiration. By maintaining a baseline level of pressure in the airways, PEEP helps to keep the alveoli open, which is essential in a condition like ARDS where alveolar stability is compromised due to fluid accumulation and inflammatory processes.

By preventing alveolar collapse, PEEP improves overall lung compliance and surface area available for gas exchange, thereby enhancing oxygenation. This is particularly important in ARDS patients, who often suffer from significant hypoxemia due to collapsed or fluid-filled alveoli. The application of PEEP helps to recruit collapsed lung units, improving ventilation-perfusion matching and ultimately leading to better oxygenation.

Thus, the correct option highlights PEEP's significant role in enhancing oxygen delivery to the bloodstream by keeping the alveoli open and functioning effectively, which is vital for managing patients with ARDS.