A nurse is caring for a patient with a penetrating chest wound. What is the nurse's immediate priority action?

Positioning in high Fowler's optimizes breathing and allows assessment for tension pneumothorax, a life-threatening emergency. Other actions (e.g., occlusive dressing, oxygen, chest tube) are important but secondary to this priority assessment.

Understanding the Clinical Scenario
The patient presents with classic signs of a tension pneumothorax following a penetrating chest wound. The assessment findings—tachycardia (HR 128 bpm), hypotension (BP 90/60 mmHg), tachypnea (RR 32/min), hypoxemia (SpO2 88%), diminished left-sided breath sounds, and asymmetric chest wall movement—indicate a progressive accumulation of air in the pleural space under pressure. The patient's posture (sitting upright, leaning forward) is a compensatory mechanism to facilitate respiratory muscle function. The immediate priority is to address the life-threatening hypoxemia and hemodynamic compromise.

Analysis of the Priority Action
The correct answer is to administer high-flow oxygen via a non-rebreather mask. In the management of trauma, the primary survey follows the ABCDE (Airway, Breathing, Circulation, Disability, Exposure) approach. While all listed interventions are necessary for a tension pneumothorax, the sequence is critical. The patient's oxygen saturation of 88% on room air signifies severe hypoxemia, which directly threatens tissue oxygenation and cardiac function. The Guidelines for Essential Trauma Care emphasize that strengthening the organization of trauma care, including immediate resuscitation priorities, can lower mortality ^[1]. Oxygenation is a foundational step in the "Breathing" assessment and management phase, taking precedence over dressing application, which addresses the wound but not the immediate systemic hypoxia.

Why Other Options Are Not the Immediate Priority
- Applying a three-sided occlusive dressing is a critical intervention for an open pneumothorax to prevent air from entering the pleural space during inspiration while allowing trapped air to escape during expiration. However, the patient is already exhibiting signs of a developing tension pneumothorax, meaning air is accumulating and not exiting. While this dressing prevents further air entry, it does not rapidly correct the existing, life-threatening hypoxemia and hemodynamic instability. Oxygenation must be optimized first.
- Preparing for immediate chest tube insertion is the definitive treatment for a tension pneumothorax, as it evacuates the trapped air and allows the lung to re-expand. However, this is a provider-level procedure that requires preparation and time. The nurse's immediate, independent action is to support the patient's failing physiology with high-flow oxygen while the team prepares for the procedure. The circulatory collapse seen in tension pneumothorax involves obstructed venous return, and maximizing oxygen content in the remaining circulating blood is a vital temporizing measure.
- Positioning the patient in high Fowler's position can facilitate chest expansion and ease breathing for patients with respiratory distress. However, the patient has already self-positioned into an upright, forward-leaning posture, which is optimal for him. Forcibly repositioning him may increase anxiety and oxygen consumption without providing a benefit greater than correcting the critical hypoxemia. The patient's current position is acceptable while the priority of oxygenation is addressed.

Pathophysiological Rationale and Clinical Integration
In a tension pneumothorax, injury to the lung or chest wall creates a one-way valve effect. Air enters the pleural space during inspiration but cannot exit during expiration. As pressure builds, the mediastinum shifts toward the unaffected side, compressing the contralateral lung and, crucially, kinking the great vessels (superior and inferior vena cava). This kinking drastically reduces venous return to the heart, leading to decreased cardiac output and the observed hypotension (obstructive shock). The Guidelines for Essential Trauma Care highlight that injury is a major cause of death and that organized trauma care improves outcomes ^[1]. The immediate provision of high-flow oxygen increases the partial pressure of oxygen in the alveoli, maximizing the oxygen saturation of the hemoglobin that is still circulating. This is the fastest way to mitigate tissue hypoxia while preparing for definitive decompression. This approach aligns with the principle that in trauma resuscitation, physiological stabilization begins simultaneously with assessment, and the most immediately life-threatening physiological derangement—in this case, severe hypoxemia—is addressed first.