Avoid the Trap: Nonexpanding Lung.

Nonexpanding lung is a mechanical complication in which part of the lung is unable to expand to the chest wall, preventing apposition of the visceral and parietal pleura. This can result from various visceral pleural disease processes, including malignant pleural effusion and empyema. Nonexpanding lung can be referred to as trapped lung or lung entrapment, both with distinct clinical features and management strategies. Early evaluation of pleural effusions is important to address underlying causes of pleural inflammation and to prevent the progression from lung entrapment to trapped lung. Some patients with trapped lung will not experience symptomatic relief with pleural fluid removal. Therefore, misrecognition of trapped lung can result in patients undergoing unnecessary procedures with significant cost and morbidity. We reviewed the current understanding of nonexpanding lung, which included causes, common presentations, preventative strategies, and recommendations for clinical care.