A nurse is caring for a patient on mechanical ventilation who suddenly develops severe respiratory distress with decreased oxygen saturation, asymmetrical chest movement, and absent breath sounds on the right side. The ventilator alarm is sounding with high peak pressures. What is the nurse's immediate priority action?

Severe distress with asymmetrical chest movement, absent breath sounds, and high peak pressures indicates tension pneumothorax, requiring immediate chest tube insertion for decompression. Other options like suctioning or bronchodilators do not address this life-threatening emergency.

Understanding the Clinical Scenario
The patient is exhibiting the classic triad of a tension pneumothorax: severe respiratory distress, asymmetrical chest movement, and absent breath sounds on the affected side. In the context of mechanical ventilation, the high peak pressure alarm is a critical clue. The ventilator is encountering increased resistance as it tries to force air into a lung that is collapsing under pressure from air trapped in the pleural space. This trapped air not only collapses the lung but also pushes the mediastinum, compressing the heart and great vessels, which leads to rapid cardiovascular collapse if not immediately addressed.

Why the Other Options Are Incorrect
- Option 1 (Increase FiO2 to 100% and notify the respiratory therapist): While increasing oxygen is a supportive measure, it does nothing to relieve the pressure building in the chest. The primary problem is mechanical compression, not a diffusion or ventilation-perfusion mismatch that can be corrected with oxygen. Waiting for a respiratory therapist delays the life-saving decompression that a nurse can and must initiate.
- Option 2 (Suction the endotracheal tube and reposition the patient): This action addresses a potential mucus plug or tube malposition, which could cause high pressures and unequal breath sounds. However, the sudden onset of distress with absent breath sounds on one side and high peak pressures in a ventilated patient is pathognomonic for tension pneumothorax, not a simple obstruction. Suctioning and repositioning would waste precious time.
- Option 3 (Administer a prescribed bronchodilator via the ventilator circuit): Bronchodilators treat bronchospasm, which typically presents with wheezing and is a bilateral process. This intervention is ineffective against a mechanical barrier caused by air in the pleural space and does not address the imminent threat of cardiovascular collapse.

Pathophysiology and Clinical Reasoning
The mechanism described in the provided case reports directly explains this emergency. Positive pressure ventilation can overdistend alveoli, leading to barotrauma and the rupture of a bleb or weakened area of the lung ^[1]. Air then enters the pleural space. A one-way valve effect can develop, where air enters the pleural space on inspiration but cannot exit on expiration. This rapidly increases intrathoracic pressure, causing a tension pneumothorax. The rising pressure collapses the ipsilateral lung (causing absent breath sounds) and shifts the mediastinum to the opposite side (compromising the contralateral lung and kinking the great vessels). This leads to the sudden hypoxemia and cardiovascular collapse described in the literature [1, 2].

The Nurse's Immediate Priority
The immediate priority is to relieve the pressure. The definitive treatment is chest tube insertion, but the life-saving immediate action is needle decompression. The case report by Prasad and Gaiwal explicitly states that after tension pneumothorax was suspected, "immediate needle decompression followed by right chest tube thoracostomy" was performed . In the NCLEX-RN context, "prepare for immediate chest tube insertion" encompasses the nurse's role in recognizing the emergency, gathering equipment, and assisting the physician with the procedure, which is the correct priority action after ensuring the patient is positioned and oxygenated. Recognizing that a sudden drop in oxygen saturation with high ventilator pressures demands a rapid clinical assessment for this life-threatening complication is the core of this scenario ^[1].