Pathophysiology
Clinical meaning
A pneumothorax occurs when air enters the pleural space, disrupting the normally negative intrapleural pressure that keeps the lung expanded. This causes partial or total lung collapse. An open pneumothorax results from a penetrating chest wall injury, while a closed pneumothorax occurs after lung surgery or spontaneous alveolar rupture. A tension pneumothorax is the most life-threatening form: air enters the pleural space but cannot escape, causing progressive pressure buildup that shifts mediastinal structures to the unaffected side, compressing the heart and great vessels. The nurse must recognize deteriorating respiratory status, report findings immediately, and assist with emergency interventions as directed.