Positive End-Expiratory Pressure (PEEP) is commonly used in mechanical ventilation. Which of the following is a primary physiological benefit of applying PEEP?

Explanation

PEEP maintains positive pressure in the airways at the end of expiration. Its primary physiological benefit is to prevent alveolar collapse (atelectasis), recruit collapsed alveoli, increase functional residual capacity (FRC), and improve ventilation-perfusion (V/Q) matching, thereby enhancing oxygenation. While PEEP can have systemic effects, such as decreasing cardiac preload (due to increased intrathoracic pressure impeding venous return) and potentially increasing pulmonary vascular resistance (especially at high levels), these are generally considered potential side effects or complications rather than primary therapeutic benefits. PEEP can also increase intracranial pressure, not reduce it, by impeding cerebral venous outflow.