INFLAMMATION OF THE PLEURA. 273 



notwithstanding that a part of the pulmonary capillaries has perished, 

 the right side of the heart, which is then always somewhat hypertro- 

 phied and dilated, is still capable of so accelerating the current of the 

 blood in the sound parts of the lung as to avert derangement of the 

 circulation. 



When an empyema " points " or opens externally, an cedematous 

 swelling of the integument makes its appearance, not, however, at the 

 most dependent part of the chest, but generally in the neighborhood 

 of the fourth or fifth rib. Soon a hard, firm tumor protrudes through 

 the intercostal space, which, after a time, begins to show fluctuation, 

 and finally discharges a large amount of pus. This termination very 

 rarely results in complete recovery, and in reinflation of the lung and 

 reoccupation of the space restored by discharge of the pus. It is 

 much more common in such cases for the thorax to collapse, and for 

 secondary displacements of the organs to occur. Still more commonly 

 there remains an imperfect closure of the thoracic opening (after point- 

 ing of an empyema), and a thoracic fistula forms, from which pus con- 

 stantly flows, either in a continuous stream or in occasional profuse 

 Cashes. A patient with such a fistula may live for many years. 



When empyema points inwardly, that is to say, into the lung, the 

 perforation is sometimes preceded by the symptoms of a slight pneu- 

 monia, bloody sputa, a renewal of the stitch in the side, etc. At other 

 times it takes place without warning, the patient suddenly discharg- 

 ing an enormous amount of purulent sputa after a violent fit of cough- 

 ing. Here, too, in very rare instances, recovery with or without retrac- 

 tion of the thorax may ensue, but symptoms of suffocation, or of pyo- 

 pneumothorax, are the more usual result (see Chapter III.). 



Perforation of empyema through the diaphragm, or into neighbor- 

 ing organs, produces violent peritonitis. 



A fatal result in recent pleurisy generally arises from collateral hy- 

 persemia, leading to intense oedema in the healthy portions of the lung. 

 Rattling sounds, frothy and often bloody sputa, and great dyspnoea 

 arise; carbonic-acid poisoning follows; the sensorium becomes be- 

 numbed, the action of the heart is weakened, the pulse grows small, 

 the extremities cool, and the sufferer soon expires. 



In other cases, compression of the lung and its capillaries gives rise 

 to incomplete filling of the left ventricle, and to engorgement and ob- 

 struction of the right ventricle and the veins of the aortic system. 

 B artels points out that, in displacement of the heart to the right, the 

 vena cava suffers flexure at its point of emergence from the foramen 

 quadrilaterum of the diaphragm, causing disturbance of the circulation. 

 This imperfect filling of the aortic system frequently gives rise, not 

 only to a small pulse, but to an excessive diminution and concentration 

 19 



