PLEURITIS. 1 



Prognosis. — Mild cases of pleurisy generally recover in a 

 few days to a week. The more serious cases, however, 

 where there is much effusion of lymph, are of longer dura- 

 tion, and though the prognosis is, in most cases, favourable, 

 yet the changes in the pleural membrane, and the adhesions 

 formed between the two layers, often continue for life. 



Cases of pleurisy associated with specific influences are 

 liable to be much protracted, or even prove fatal from the 

 effused lymph becoming purulent. This condition is termed 

 empysema. 



Morbid Anatomy. — The inflammatory process commences 

 in hypercemia of the pleural membrane. Exudation of fluid 

 and blood- cells into the pleural cavity soon follow. 



Gradually the surfaces become opaque, roughened, and 

 very vascular, and covered over with a fibrinous layer, 

 whilst more or less fluid transudes into the cavity. 



The exudation from the vessels forms a soft, elastic 

 membranous or reticulated coating, enclosing many cells in 

 its meshes. 



In this way the opposed surfaces of the pleural membrane 

 may be glued together. 



The exuded liquid varies considerably in amount, and is 

 always turbid, in this respect difi'ering from the non- 

 inflammatory efi'usions. 



It contains flakes and masses of coagulated fibrin, and 

 many cells, which in the early stages are almost entirely 

 emigrants. 



If now the inflammation subsides, and the efi'used fluid is 

 not sufficient to prevent the two surfaces coming into con- 

 tact, they may become adherent, the union being effected 

 by the formation of connective-tissue. If, however, the 

 inflammation is severe, or there is much effusion, organi- 

 zation and adhesion cannot be effected. 



The presence of much fluid interferes with its own 



