PneumothoraxRadlex concept

An accumulation of air or gas in the pleural space, which may occur spontaneously or as a result of trauma or a pathological process, or be introduced deliberately ( pneumothorax, artificial). (Dorland, 27th ed) [MeSH] Pathophysiology.—Pneumothorax refers to the presence of gas in the pleural space. Qualifiers include spontaneous, traumatic, diagnostic, and tension. Tension pneumothorax is the accumulation of intrapleural gas under pressure. In this situation, the ipsilateral lung will, if normal, collapse completely; however, a less than normally compliant lung may remain partially inflated. Radiographs and CT scans.—On chest radiographs, a visceral pleural edge is visible (Fig 55) unless the pneumothorax is very small or the pleural edge is not tangential to the x-ray beam. Tension pneumothorax may be associated with considerable shift of the mediastinum and/or depression of the hemidiaphragm. Some shift can occur without tension because the pleural pressure in the presence of pneumothorax becomes atmospheric, while the pleural pressure in the contralateral hemithorax remains negative. [Fleischner Society]