Final answer:
The priority nursing intervention after a transesophageal echocardiogram is to monitor the client's oxygen saturation to ensure that the client is maintaining adequate oxygenation post-procedure.
Step-by-step explanation:
The priority nursing intervention after a client has undergone a transesophageal echocardiogram is to monitor the client's oxygen saturation. This is because the procedure involves sedation and the insertion of a probe into the esophagus, which can potentially impact breathing and oxygen levels. It is essential to ensure that the client is maintaining adequate oxygenation following the procedure. Monitoring vital signs, especially oxygen saturation, is crucial for detecting any immediate post-procedural complications. While administering pain medication, assisting with ambulation, and scheduling follow-up appointments are important, they are not the immediate priority following a transesophageal echocardiogram.