What does PEEP indicate in mechanical ventilation?

PEEP stands for Positive End Expiratory Pressure, which refers to a mode of mechanical ventilation that maintains a certain amount of pressure in the airways at the end of expiration. This positive pressure helps keep the alveoli (the small air sacs in the lungs) open, thereby increasing functional residual capacity and improving oxygenation.

By preventing the collapse of alveoli and allowing for better gas exchange, PEEP plays a crucial role in enhancing lung compliance and minimizing ventilatory work. This is particularly important in patients with conditions such as acute respiratory distress syndrome (ARDS), where maintaining adequate oxygenation is critical.

The other terms presented do not accurately define PEEP: the idea of "pressure during inspiratory effort" refers to a different aspect of ventilation, "pulse end expiratory pressure" does not have any relevance in this context, and "preventive end expiratory pressure" is not a recognized term in mechanical ventilation. Thus, PEEP's role in providing positive end expiratory pressure is essential for effective respiratory support in mechanically ventilated patients.