Avoid the Trap: Non-expanding Lung.

ABSTRACT Non-expanding lung (NEL) 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 (MPE) and empyema. NEL can be referred to as trapped lung (TL) or lung entrapment (LE), both with distinct clinical features and management strategies. Early evaluation of pleural effusions is important to address underlying causes of pleural inflammation and prevent the progression from LE to TL. Some patients with TL will not experience symptomatic relief with pleural fluid removal. Therefore, misrecognition of TL can result in patients undergoing unnecessary procedures with significant cost and morbidity. This paper will review the current understanding of NEL including causes, common presentations, preventative strategies, and recommendations for clinical care.