Final answer:
To properly size an oropharyngeal airway, measure from the patient's mouth to the angle of the jaw, ensuring the OPA is neither too small nor too large to prevent obstruction or trauma.
Step-by-step explanation:
To measure for the correct sizing of an oropharyngeal airway (OPA), the most common method involves estimating the size of the airway device by measuring from the patient's mouth to the angle of their jaw (mandible). This measurement correlates to the approximate distance from the lips to the pharynx. An OPA that is too small may not effectively hold the tongue out of the way, whereas an OPA that is too large can cause trauma to the oropharynx. Once a size is selected, it is important to monitor the patient for any signs of obstruction or distress.