How should a nurse proceed upon finding a patient with a history of pulmonary embolism suddenly reporting dyspnea and chest pain postoperatively?

Pulmonary embolism is an acute obstruction of pulmonary arteries by a thrombus, leading to ventilation-perfusion mismatch, increased pulmonary vascular resistance, right ventricular strain, hypoxemia, and potential cardiovascular collapse. Postoperative patients are at high risk due to venous stasis and hypercoagulability. Rationale: A. Encouraging deep breathing exercises does not address the acute obstruction in the pulmonary circulation. While beneficial for atelectasis prevention, it is inappropriate as a primary response to suspected pulmonary embolism. B. Elevating the head of bed improves ventilation and reduces work of breathing, while immediate notification of the provider ensures urgent diagnostic and therapeutic intervention (e.g., anticoagulation or thrombolysis). This is the priority response to suspected pulmonary embolism. C. Morphine may be used cautiously for severe chest pain and anxiety in confirmed cases, but it does not treat the underlying embolic obstruction and should not delay emergency escalation and assessment. D. Chest percussion therapy is used for secretion mobilization in conditions like pneumonia or atelectasis. It is contraindicated in pulmonary embolism and does not address the vascular obstruction causing symptoms.