Final answer:
When a patient regurgitates vomit during ventilation with a bag-mask device, the oral airway should be removed and the patient should be rolled onto their side to prevent further obstruction of the airway and aspiration of vomit into the lungs.
Step-by-step explanation:
When a patient starts regurgitating large amounts of vomit while being ventilated with a bag-mask device, the oral airway should be removed to prevent further obstruction of the airway. Rolling the patient onto their side can help facilitate the removal of the oral airway and prevent aspiration of vomit into the lungs. This position also helps to maintain an open airway and allows for effective drainage of fluids.