What is a Nasopharyngeal Airway?
A nasopharyngeal airway, also referred to as an NPA, is a type of basic airway adjunct. The nasopharyngeal airway tube is designed to be inserted into the nasal passageway to help secure an open airway.
After a patient loses consciousness, the muscles in the jaw will usually relax. This unfortunately creates a situation where the tongue slides back to obstruct the patient’s airway. When this happens, airway management becomes a necessity for healthcare providers, and a nasopharyngeal airway is one of the available tools they can use.
The purpose of the flared end is to prevent the device from becoming lost inside the patient’s nose.
An NPA is often used as an alternative to an OPA (oropharyngeal airway) in patients who require a basic airway management adjunct to keep the airway patent. A nasopharyngeal airway is a soft rubber or plastic uncuffed tube that provides a conduit or passage for airflow between the nares and the pharynx.
Unlike oral airways, NPAs can be used in patients who are conscious, semiconscious, or unconscious, for patients with an intact cough and gag reflex. A nasopharyngeal airway is indicated when the insertion of an OPA is technically difficult or dangerous.
Examples of this include patients with a gag reflex, trismus (or lockjaw), wiring of the jaws, or massive trauma around the mouth. A nasopharyngeal airway can also be used in neurologically impaired patients, including poor pharyngeal tone or coordination leading to upper airway obstruction.
How to Choose the Correct Size of Nasopharyngeal Airway
The correct size of a nasopharyngeal airway is chosen by measuring the device on the patient. Healthcare providers will compare the outer circumference of the nasopharyngeal airway with the inner aperture of the nares. The device should reach from the patient’s nostril to the earlobe along the angle of the jaw.
The NPA mustn’t be too large. If it is, it may cause sustained blanching of the nostrils. Some providers will also use the diameter of the patient’s smallest finger as a guide to selecting the proper size.
How to Insert a Nasopharyngeal Airway
Inserting a nasopharyngeal airway once healthcare providers have selected the proper size entails just three steps:
- Lubricate the nasopharyngeal airway with a water-soluble lubricant or anesthetic jelly.
- Insert the airway through the nostril in a posterior direction perpendicular to the plane of the face.
- Pass the nasopharyngeal airway gently along the floor of the nasopharynx.
Sometimes healthcare professionals will encounter resistance while inserting an NPA. When this happens, there are two alternative courses of action:
- Slightly rotate the NPA tube to facilitate insertion at the angle of the nasal passage and nasopharynx.
- Attempt placement through the other nostril; patients will often have different sized nasal passages, and it may fit into the other more easily.
Healthcare providers will need to reevaluate the patient frequently and maintain head tilt by providing anterior displacement of the mandible using a chin lift or jaw thrust. Blood, vomit, mucus, or the soft tissues of the pharynx can obstruct the nasopharyngeal airway, which has a small internal diameter. Therefore, frequent evaluation and suctioning of the patient’s airway may be necessary to ensure patency.
There are several things to be aware of when using an NPA to secure a patient’s airway.
- Care should be taken when inserting an NPA to avoid complications. The airway can irritate the mucosa or lacerate adenoidal tissue and cause bleeding, with possible aspiration of clots into the trachea.
- An improperly sized nasopharyngeal airway could accidentally enter the esophagus. With active ventilation (using bag-mask ventilation), the NPA may cause gastric inflation and possible hypoventilation.
- An NPA may cause laryngospasm and vomiting, even though it is usually tolerated by semiconscious patients.
- Use caution when inserting a nasopharyngeal airway in patients with facial trauma because of the risk of misplacement into the cranial cavity through a fractured cribriform plate.
Precautions when Using NPAs and OPAs
There are some general precautions to take when using an OPA or NPA:
- Always check spontaneous respirations immediately after insertion of either an OPA or NPA
- If respirations are inadequate or absent, start positive-pressure ventilations immediately using an appropriate device
- If adjuncts are unavailable, use mouth-to-mask barrier device ventilation