What does the PEP device do during expiration?

The PEP (Positive Expiratory Pressure) device is designed to enhance expiratory flow by creating resistance during expiration. This controlled resistance helps to keep the airways open and can facilitate the mobilization of secretions from the lungs. By regulating expiratory resistance, the PEP device helps to improve ventilation by preventing airway collapse, especially in individuals with conditions that may lead to obstructive airway issues.

The primary goal of using a PEP device is to improve airway clearance and enhance lung function. Patients who use the device exhale into it, which causes the pressure inside the airways to increase, effectively helping to keep the small airways open and allowing for better air exchange. This action can reduce the work of breathing and can be particularly beneficial in conditions like cystic fibrosis or COPD.

In this context, the other choices do not accurately reflect the mechanism of action of the PEP device. It does not increase airway obstruction, assist with inhalation, or provide supplemental oxygen. Instead, it focuses primarily on enhancing expiratory performance and aiding in airway clearance through controlled resistance.