A nurse is caring for a 72-year-old patient who underwent total hip replacement surgery 2 days ago. The patient reports sudden onset of chest pain, shortness of breath, and anxiety. Vital signs are: temperature 98.6°F (37°C), heart rate 110 bpm, respiratory rate 28/min, blood pressure 90/60 mmHg, and oxygen saturation 88% on room air. What is the priority nursing intervention?

The priority is to apply supplemental oxygen and notify the physician immediately due to suspected pulmonary embolism, a life-threatening post-surgical complication. Other interventions are secondary to stabilizing oxygenation and obtaining urgent medical evaluation.

Clinical Presentation and Pathophysiology
The patient’s sudden-onset chest pain, dyspnea, tachypnea (respiratory rate 28/min), tachycardia (heart rate 110 bpm), hypotension (blood pressure 90/60 mmHg), and critically low oxygen saturation (88% on room air) 2 days after a total hip replacement is a classic presentation for an acute pulmonary embolism (PE). Orthopedic surgeries, particularly hip arthroplasty, carry a high risk for deep vein thrombosis (DVT), which can dislodge and obstruct pulmonary arteries ^[2][3]. When a thrombus obstructs pulmonary vasculature, it increases pulmonary artery pressure and strains the right ventricle, leading to reduced cardiac output and impaired contractility, a condition known as right ventricular dysfunction (RVD) ^[3]. This explains the hypotension and tachycardia, as the heart struggles to maintain forward flow against increased resistance, while the ventilation-perfusion mismatch causes severe hypoxemia ^[3].

Priority Nursing Intervention
In this hemodynamically unstable patient with suspected PE, the immediate priority is to address life-threatening hypoxemia and ensure rapid medical intervention. Applying supplemental oxygen directly targets the critical hypoxemia that is driving the patient’s distress and organ dysfunction . Simultaneously notifying the physician is essential because definitive management—such as emergent computed tomography pulmonary angiography for diagnosis, anticoagulation, or in severe cases, thrombolysis or surgical thrombectomy—must be initiated without delay ^[2][3]. The case report by Hu et al. highlights how rapid deterioration can occur, with patients progressing to hemodynamic collapse requiring advanced interventions like veno-arterial extracorporeal membrane oxygenation when first-line measures fail ^[2]. Therefore, the nurse’s role is to stabilize oxygenation and activate the emergency response system immediately.

Analysis of Incorrect Options
Administering prescribed pain medication (Option 1) is inappropriate because while chest pain is present, the priority is treating the underlying hypoxemia and hemodynamic instability. Pain medication could cause respiratory depression, further compromising the patient’s already precarious oxygenation status. Encouraging deep breathing and coughing (Option 2) is beneficial for preventing atelectasis and pneumonia postoperatively but is insufficient and potentially harmful as a sole intervention for a massive PE; the patient needs immediate oxygen supplementation and advanced medical care. Positioning in high Fowler’s position (Option 3) can assist with chest expansion and is a supportive measure, but it does not directly correct the profound hypoxemia. The evidence summary on perioperative hypoxemia management emphasizes that nursing interventions must be prioritized based on the severity of the oxygen deficit, with oxygen therapy being a foundational, immediate action .