What characteristic helps differentiate between a BVM and an NPA?

The characteristic that helps differentiate between a bag-valve-mask (BVM) and a nasopharyngeal airway (NPA) is that a BVM provides positive pressure ventilation, while an NPA does not.

When using a BVM, it is essential for ensuring adequate ventilation in patients who are unable to breathe effectively on their own. The device creates a seal over the patient’s mouth and nose, allowing the operator to deliver air (or oxygen) into the lungs by squeezing the bag. This method effectively increases intrathoracic pressure, forcing air into the lungs, hence the term "positive pressure ventilation."

On the other hand, an NPA is primarily a device used to maintain airway patency by providing a clear passage for air to enter the trachea. It does not introduce air into the lungs on its own, nor does it provide any form of ventilation; its role is solely to prevent airway obstruction by facilitating airflow through the nasal passage when the patient is unable to protect their airway.

Understanding these roles is fundamental in airway management and highlights the distinct purposes of each device in emergency care.