A client has just been admitted to the postsurgical unit following a below-the-knee amputation. Which of the following measures should her care team prioritize to prevent atelectasis during the client's immediate recovery?

Atelectasis — the collapse or partial collapse of lung alveoli — is a common postoperative complication, particularly following surgery requiring anesthesia, which depresses respiratory drive and inhibits deep breathing. The most effective evidence-based interventions to prevent atelectasis are deep-breathing exercises (including incentive spirometry) and early mobilization. Deep breathing recruits collapsed alveoli by increasing tidal volume and reinflating collapsed lung segments, while early ambulation promotes normal diaphragmatic excursion and reduces splinting of the chest wall. These nonpharmacological measures are the cornerstone of postoperative pulmonary care. Limited hydration would actually thicken secretions and impair mucociliary clearance, worsening atelectasis risk; a high-humidity environment alone is insufficient. Bedrest and supplementary oxygen address hypoxemia but do not treat or prevent the underlying alveolar collapse — rest in fact promotes retention of secretions. Administration of bronchodilators is appropriate for reactive airway disease or bronchospasm but is not a first-line prophylactic measure for simple postoperative atelectasis in a patient without a documented obstructive pulmonary condition. Therefore, deep-breathing exercises combined with early mobilization is the highest-priority intervention.