In ventilator settings, what does high PEEP indicate?

High Positive End-Expiratory Pressure (PEEP) is applied in ventilator settings primarily to improve oxygenation in patients with severely compromised lung function. It keeps the alveoli open at the end of expiration, thus preventing them from collapsing and facilitating better gas exchange. When a patient exhibits poorly compliant lungs, which can occur in conditions such as Acute Respiratory Distress Syndrome (ARDS) or pneumonia, higher levels of PEEP may be necessary to maintain adequate lung recruitment and improve ventilation-perfusion matching.

In such situations where lung compliance is poor, more PEEP can help to recruit collapsed or poorly ventilated areas of the lungs, allowing for greater surface area available for gas exchange. This is critical in managing patients with significant respiratory failure or those who are dependent on mechanical ventilation. Hence, a high PEEP setting indicates an attempt to optimize lung mechanics in the context of less compliant lung tissue, underscoring its relevance in respiratory management in critical care.