The NPA is a tube that is designed to be inserted into the nasal passageway to secure an open airway. When a patient becomes unconscious, the muscles in the jaw commonly relax and can allow the tongue to slide back and obstruct the airway. This makes airway management necessary, and an NPA is one of the available tools. The purpose of the flared end is to prevent the device from becoming lost inside the patient's nose.
As with other catheters, NPAs are measured using the French catheter scale.
These devices are used by emergency care professionals such as EMTs and paramedics in situations where an artificial form of airway maintenance is necessary, but tracheal intubation is impossible, inadvisable, or outside the practitioner's scope of practice. An NPA is often used in conscious patients where an oropharyngeal airway would trigger the gag reflex.