How do you determine the correct size for an oropharyngeal airway?

• A. Measure from nostril opening to earlobe
• B. Measure from lips to jawline
• C. Measure from chin to base of tongue
• D. Measure from corner of the mouth to angle of mandible

Answer: (D)

Sizing an oropharyngeal airway hinges on matching the device’s length to the path into the back of the throat so the tongue is effectively displaced without irritating tissues. The best way to estimate that length is to measure from the corner of the mouth to the angle of the mandible. This landmark-based measurement corresponds to the distance the airway must travel to reach the base of the tongue and sit with the flange at the lips, allowing the tip to rest at the back of the oropharynx to keep the airway open in an unconscious patient. If the airway is too short, the tongue can continue to block the passage; if it’s too long, it can irritate or injure tissues or trigger gagging in a semi-conscious patient. The other suggested measurements don’t reliably reflect the appropriate external length of the airway device: nostril-to-ear measurements pertain to nasopharyngeal sizing, while other options don’t correspond to a consistent anatomical landmark for this purpose.