The typical measurement for a nasopharyngeal airway is from the corner of the nose to the earlobe or tragus.

• A. Corner of the nose to earlobe/tragus
• B. Center of mouth to jaw
• C. Nostrils to chin
• D. Ear to nose

Answer: (A)

Sizing a nasopharyngeal airway relies on using an anatomical landmark to match depth. Measuring from the nostril to the earlobe or tragus estimates how far the airway needs to extend into the nasopharynx. This depth places the tip in the nasal passage behind the soft palate, not too shallow in the nostril and not so deep that it irritates or enters the pharynx or larynx. If the airway is too short, it won’t bypass the tongue and may be ineffective; if it’s too long, it can cause gagging or airway obstruction. This landmark-based approach is practical and works across ages, with size adjustments for pediatric patients as needed.