Oropharyngeal Airway Sizing and Placement

Introduction to Oropharyngeal Airway Sizing

The American Heart Association recommends measuring the distance from the patient's maxillary incisors (or corner of the mouth) to the angle of the mandible for selecting an appropriately sized oropharyngeal airway (OPA), with the maxillary incisors-to-angle measurement providing superior ventilation outcomes 1, 2

Avoid measurement techniques using the little finger or anterior nares, as these do not correlate with airway anatomy and are unreliable 3

OPAs should only be used in unconscious (unresponsive) patients with no cough or gag reflex and should be inserted only by trained personnel 1, 2
Incorrect insertion can displace the tongue into the hypopharynx, causing complete airway obstruction rather than relieving it 1, 2
The airway facilitates bag-mask ventilation by preventing tongue obstruction, though no studies have specifically validated their use in cardiac arrest patients 1, 2
In patients where oral airway placement is contraindicated (clenched jaw, intact gag reflex), nasopharyngeal airways are better tolerated 1, 2
However, in the presence of known or suspected basal skull fracture or severe coagulopathy, an oral airway is strongly preferred over nasopharyngeal routes 2, 3