Pneumonectomy, or surgical removal of an entire lung, is performed most frequently for management of bronchogenic carcinoma. In this setting, pneumonectomy is required over lesser resection, such as lobectomy, when the tumor is located in a main stem bronchus or the proximal bronchus intermedius, adjacent to the right upper lobe orifice, or when the tumor extends across a major fissure . Pneumonectomy may rarely be performed for pulmonary metastases or for a variety of benign diseases, such as inflammatory lung disease (eg, pulmonary tuberculosis, fungal infections, and bronchiectasis), traumatic lung injury, congenital lung disease, and bronchial obstruction with a destroyed lung .
Pneumonectomy is associated with a variety of reasonably predictable anatomic changes, significant decrements in pulmonary function, and a number of potential complications that involve the respiratory system, the cardiovascular system, and the pleural space  (table 1). The preoperative evaluation of the patient being considered for pneumonectomy, and clinical issues relating to the outcome, sequelae, and complications following pneumonectomy will be reviewed here. A general discussion of preoperative evaluation prior to lung resection surgery is presented separately. (See "Preoperative evaluation for lung resection".)
Immediately following pneumonectomy, air fills the space previously occupied by the lung (ie, the postpneumonectomy space, or PPS). Unlike the situation with most other forms of thoracic surgery, a chest tube is not inserted following pneumonectomy, and the air is therefore not evacuated. Over time, a number of changes result in a decrease in the size of the PPS, including elevation of the hemidiaphragm, hyperinflation of the remaining lung, and shifting of the mediastinum towards the PPS. At the same time, there is progressive resorption of air in the PPS and replacement with fluid.
Chest radiographic findings immediately after surgery demonstrate the trachea to be midline and the PPS to be filled with air (image 1A-B). Within 24 hours the ipsilateral hemidiaphragm becomes slightly elevated, the mediastinum shifts slightly towards the PPS, and fluid starts accumulating in the PPS. As a general rule, fluid accumulates at a rate of approximately two rib spaces per day. After two weeks, 80 to 90 percent of the PPS is filled with fluid.
By chest radiograph, complete opacification of the hemithorax after pneumonectomy takes an average of approximately 4 months, with a range from 3 weeks to 7 months . Unexpectedly rapid accumulation of fluid into the PPS in the immediate postoperative period should raise concerns for hemorrhage into the PPS, infection of the PPS, or the development of a chylothorax. While the chest radiograph typically demonstrates complete opacification of the hemithorax, chest CT scans demonstrate that only a small fraction of patients have obliteration of their PPS, with most patients having residual fluid and/or air . The length of time following pneumonectomy does not correlate with complete obliteration of the space nor the amount of fluid remaining in the space.