Final answer:
After a transesophageal echocardiogram, if the client has no active gag reflex, the nurse should withhold food and fluids to prevent complications.
Step-by-step explanation:
After a transesophageal echocardiogram, if the nurse observes that the client has no active gag reflex, it is important to withhold food and fluids. This is because the absence of a gag reflex can indicate a risk of aspiration, where food or fluids may enter the airway and cause complications. By withholding food and fluids, the nurse can help prevent this from happening.