Final answer:
The priority action by the nurse using Maslow's hierarchy of needs is to determine respiratory status, as it is the most pressing physiological need for a client with pneumonia.
Step-by-step explanation:
Based on Maslow's hierarchy of needs, the priority action for a nurse when an older adult client with pneumonia refuses hospital admission is to determine respiratory status. This takes precedence because according to Maslow's hierarchy, physiological needs such as breathing are the most fundamental and must be met before addressing higher-level needs. Respiratory status is critical in pneumonia patients, as it can deteriorate quickly and poses a direct threat to the patient's life. Ensuring that patients are able to maintain adequate oxygenation and respiratory function is essential in managing pneumonia effectively. Although it is important to address the emotional and educational needs of the patient, such as encouraging verbalization of fears and providing teaching about new medications, these actions are secondary to the immediate physiological requirement of stabilizing the patient's breathing and oxygenation.