pneumothorax

(nu-mo-tho’raks) (Gr. rvedua air + θώραξ thorax]. An accumulation of air or gas in the pleural cavity. The air enters either by an external wound, a lung perforation, from burrowing absce es, or from the rupture of a superficial lung cavity. Pneumothorax is apt to be of sudden onset, and to be announced by collapse. It is attended with sudden and severe pain and rapidly increasing dyspnea. Percu ion shows a wide diffusion of the tympanitic sound over the dilated side. There are no rales, but dulne is present as fluid forms, and fluctuation or succu ion, and a metallic echo on strong percu ion over the air. When a communication exists with the bronchi, metallic respiration or tinkling is heard. artificial p., pneumothorax induced intentionally by artificial means, as by the injection of nitrogen gas: employed in the treatment of pulmonary tuberculosis. Cf. For lan in i treatment under treatment. valvular p., that which is characterized by an aperture through the pleura which has a slit with a valve-like action.