Another valid method to measure an OPA is from the side of the mouth to which landmark?

• A. Ear lobe
• B. Nose
• C. Glabella
• D. Cheekbone

Answer: (A)

Measuring an oropharyngeal airway length is all about lining up the device with the depth of the oropharynx so the tip sits behind the tongue without extending too far. The side of the mouth to the ear lobe is a reliable, quick external landmark because that distance roughly corresponds to how far back the airway sits in the throat when the patient is unconscious. It gives a consistent estimate of the needed length and is easy to identify in the field. Other landmarks like the nose, the glabella, or the cheekbone don’t correlate well with the depth of the oropharynx, so they aren’t used for sizing. (Note: another common method is measuring from the corner of the mouth to the angle of the mandible.)