What role does moderate PEEP play in the lung protective strategy?

Moderate PEEP (Positive End-Expiratory Pressure) is utilized in lung protective strategies primarily to aid in recruiting collapsed or under-inflated alveoli, improving overall lung function and oxygenation. By keeping the alveoli open during expiration, PEEP helps maintain functional residual capacity (FRC) and prevents alveolar collapse, which can occur in conditions such as Acute Respiratory Distress Syndrome (ARDS). This recruitment increases the surface area available for gas exchange, enhancing oxygenation and reducing the work of breathing.

The application of moderate PEEP thus allows for better distribution of ventilation and improves the ventilation-perfusion ratio, which is critical in optimizing lung mechanics and reducing the risk of ventilator-induced lung injury. Maintaining open alveoli not only aids in providing adequate oxygenation but also reduces shunting and improves overall respiratory efficiency.