The rate of formation and lymphatic removal of fluid in pleural effusions.

Courtice and Simmonds (1) have shown the importance of lymphatic drainage from the serous cavities. They showed that protein labeled with T-1824 and injected into the pleural cavity in cats is removed exclusively by the lymphatic vessels. The rate of removal of labeled protein from the pleural cavity therefore is a measure of lymphatic flow. Burgen and Stewart (2) described a method for measuring the rate of formation and removal of protein-containing fluid from the pleural cavity in dogs. In the present paper, a method of measuring the average lymphatic flow of fluid out of the pleural cavity and the net fluid entry into the pleural cavity is described. This method afforded an opportunity to measure the rates of formation and removal of protein-containing fluid in established pleural effusions of varying etiology in man.