Final answer:
The nurse is providing initial emergency care to a patient experiencing acute shortness of breath.
Step-by-step explanation:
The actions of the nurse in this scenario can be described as providing initial emergency care to a patient experiencing acute shortness of breath. By elevating the head of the patient's bed, checking the pulse oximetry, and administering oxygen, the nurse is taking immediate steps to address the patient's respiratory distress. Notifying the patient's physician afterwards ensures that ongoing medical attention and further treatment can be provided if necessary.