Pneumothorax.
DEFINITION.—A collection of atmospheric air or of gas in the pleural cavity. Pneumothorax ([Greek: pneuma] and [Greek: thôrax]).
In ancient times gaseous collections were frequently noticed in serous cavities, especially on opening the chest for empyema and at post-mortem examinations. The presence of air resulting from laceration of the lungs by fractured ribs was known and designated as emphysema thoracis. Air in the pleura was considered as an accidental complication which occurred with empyema or as formed after death. Morgagni and others mentioned the presence of gas as formed in the pleural cavity. Itard223 was the first to speak of it as a disease and to name it pneumothorax. Owing to the imperfect knowledge of pathology at that period, he attributed the production of the air to the decay of the lung from chronic suppuration, and to the decomposition of the long-retained pus. Laennec was the first to give an accurate anatomical and clinical account of the disease.
223 Thèse de Paris, 1803.
HISTORY.—Pure pneumothorax—that is, pneumothorax caused by the presence of air alone in the pleura—is but rarely met with, except for a short time, when it has been introduced from without by traumatic injuries. The irritating effects of gas, unless it comes in small quantities through the ribs from wounds in the chest-walls, are very frequently followed in a short time by the production of a quantity of serosity or of pus. If air is introduced into the pleural cavity from perforation of the lung, there is also liquid matter from the lungs of such a character as at once to provoke inflammatory action. Such a condition is then denominated hydro-pneumothorax or pyo-pneumothorax. The latter was, in fact, recognized by Hippocrates by the sign of succussion, though not so designated.
ETIOLOGY.—Laennec divided pneumothorax into three distinct varieties: 1st, essential pneumothorax, resulting from the spontaneous formation of gas in the pleural cavity; 2d, pneumothorax from putrid decomposition of liquids effused into the pleura; 3d, pneumothorax by perforation, due to rupture into the pleura or to an accidental opening by which atmospheric air or gas from the lungs is introduced into the pleural cavity. This division, having Laennec's high authority, was for a long time generally received. It has now been established that the pleuræ cannot secrete air.
Proust224 collected 25 cases of so-called spontaneous pneumothorax, and showed that they could all be otherwise satisfactorily explained. In some cases errors of diagnosis had been made by mistaking tympanitic sonority at the anterior-superior portion of the chest, or the existence of the amphoric breathing found in pleurisy, for pneumothorax. Some were cases of pneumonia in which tympanitic percussion resonance deceived observers. Then, again, there was found, among the cases cited, pneumothorax resulting from rupture of a tubercular cavity or of a hydatid. In tubercular cases Proust found that the orifices made were so small—no larger, as Gairdner of Edinburgh had stated, than a pin's point—that they could not be detected, or that they had cicatrized before the post-mortem examination, or perhaps closed by adhesive false membranes. Other investigations by Ewald225 and Jaccoud226 have confirmed Proust's views that essential pneumothorax does not occur. Researches in pathological physiology disprove the possibility of a serous membrane producing a secretion of gas or of its passing from the blood through the capillary walls. We therefore conclude that pneumothorax from secretion of air within the pleura is contrary to physiological facts generally accepted, and is disproved by pathological investigations.
224 Ibid., 1862.
225 Quoted by Fraentzel, Ziemssen, vol. iv.
226 Gaz. hébd., 2ème serie, 1864.