Final answer:
To prevent postoperative pneumonia and atelectasis, the nurse should prioritize educating the client on the use of incentive spirometry, as it's effective in maintaining lung volume and clearance of secretions in patients with reduced mobility after surgery.
Step-by-step explanation:
Among the postoperative interventions to prevent postoperative pneumonia and atelectasis, the priority should be educating the client on the use of incentive spirometry. Incentive spirometry is particularly useful for patients with reduced mobility after surgery as it encourages voluntary deep breathing. This not only helps in keeping the air passages open but also prevents fluid accumulation in the lungs, which is crucial for the prevention of atelectasis and pneumonia. Unlike the administration of inhaled corticosteroids or oropharyngeal suctioning, which are specific medical treatments, or pursed-lip breathing, which is more beneficial for chronic obstructive pulmonary disease (COPD) management, incentive spirometry is a preventative measure that physically assists in maintaining lung volume and avoiding the pooling of secretions.