Final answer:
An incorrectly sized oropharyngeal airway can cause inadequate ventilation, which may lead to hypoxia or cardiac arrest due to an obstructed airway.
Step-by-step explanation:
If an oropharyngeal airway device is not the correct size for the patient, it can lead to numerous complications. An incorrectly sized oropharyngeal airway can result in inadequate ventilation, potentially causing an obstruction of the airway. If the device is too small, it may not effectively prevent the tongue from obstructing the pharynx; if too large, it could cause trauma to the soft tissues and even push the epiglottis down, worsening the airway obstruction. This could lead to hypoxia (decreased oxygen reaching the tissues), increased risk of aspiration, and possibly cardiac arrest if the airway is not opened promptly.