How to Measure and Use OPA and NPA in Airway Management

Sep 10, 2024 Ultrassist

In airway management, two essential tools - Oropharyngeal Airways (OPA) and Nasopharyngeal Airways (NPA) - help keep the airway open in patients who are unable to maintain a patent airway independently. Measuring these devices properly ensures their effectiveness and prevents complications. Here's a detailed guide on how to measure and use OPA and NPA for optimal patient care.

Understanding OPA and NPA

OPA and NPA are both airway adjuncts used to maintain or restore an open airway, particularly in emergencies. While an OPA is placed through the mouth, an NPA is inserted through the nose. These devices prevent the tongue from blocking the airway or create a path through an obstructed nasal passage.

OPA (Oropharyngeal Airway): A curved plastic device designed to fit along the contour of the mouth and throat.
NPA (Nasopharyngeal Airway): A flexible tube inserted into the nasal passage, extending to the pharynx.

How to Measure an OPA

To measure an OPA correctly, follow these steps:

Positioning: Have the patient lie in a supine position, or if they are unconscious, ensure they are in a safe position for airway insertion.
Sizing the OPA: Measure from the corner of the patient’s mouth to the angle of the jaw (just below the ear lobe). This distance indicates the appropriate length of the OPA to use.
Checking Fit: If the OPA is too long, it may push the tongue backward, worsening airway obstruction. If too short, it will not adequately displace the tongue from blocking the airway.
Insertion: Ensure the patient is unresponsive before insertion, as OPA use in conscious patients can trigger gag reflexes.

How to Measure an NPA

Measuring an NPA requires a different approach:

Sizing the NPA: To select the right size, measure from the tip of the patient’s nose to the tragus (the small cartilage part in front of the ear). This distance corresponds to the correct length of the NPA tube.
Diameter Selection: The diameter of the NPA should be slightly smaller than the diameter of the patient’s nostril. Most NPAs are color-coded based on size, but double-check the measurement to ensure an accurate fit.
Insertion: Apply a water-soluble lubricant to the tube. Gently insert the NPA into the nasal passage, directing it along the floor of the nasal cavity until it reaches the back of the throat.

When to Use an OPA or NPA

OPA is generally used for unconscious patients without a gag reflex, such as those under anesthesia or in a deep state of unconsciousness.
NPA is often used for conscious or semi-conscious patients because it is better tolerated in those who retain a gag reflex.

Benefits and Risks

OPA Benefits: Simple, non-invasive airway adjunct that can be used quickly in emergencies.
OPA Risks: Can cause airway trauma or induce vomiting if used on a conscious patient.
NPA Benefits: Versatile option for both conscious and unconscious patients, less risk of airway trauma compared to OPA.
NPA Risks: Incorrect sizing may lead to nasal bleeding or discomfort, and care should be taken with patients who have facial trauma or head injuries.

Proper Care and Maintenance

Airway adjuncts like OPA and NPA should be kept sterile and well-maintained. After use, ensure proper cleaning or disposal according to protocol. Reusable devices should be cleaned thoroughly to prevent cross-contamination.

OPA and NPA are vital tools in airway management, especially in emergency and prehospital settings. Correct measurement and use can make the difference between life and death in situations where airway patency is compromised. Proper training in both OPA and NPA measurement and insertion techniques ensures that healthcare providers are prepared to manage patients' airways effectively.

Recommend: Infant Airway Management Trainer for OPA and NPA measurement and insertion