294: DISEASES OF THE PLEURA. 



ID pneumothorax they have disappeared, or become prominent. 3. In 

 emphysema the vesicular breathing is weak, but is not absolutely want- 

 ing ; or we hear the sounds of bronchitis in its place. In pneumotho- 

 rax we never hear vesicular murmur, but metallic sounds are frequent- 

 ly audible. 4. In emphysema the pectoral fremitus is perceptible ; in 

 pneumothorax it is hardly ever present. 



Pneumothorax is to be distinguished from large, empty, superficial- 

 ly situated cavities over which upon percussion we hear the metallic 

 ring, and in which amphoric breathing and metallic tinkling are audi- 

 ble upon auscultation by the following points of difference : 1. The 

 thorax is depressed over a large superficial cavern ; over a pneumo- 

 thorax it is dilated. 2. Where a cavity exists, the pectoral fremitus 

 frequently is strengthened ; in pneumothorax it is imperceptible. 3. 

 The rdles in a cavity are usually loud and numerous ; in pneumothorax 

 they are few and faintly audible. 4. Where there is only a cavity, 

 the neighboring organs are not dislocated ; in pneumothorax the dis- 

 placement is generally well marked. 5. In a cavity the pitch of the 

 tympanitic percussion-sound is altered by opening and shutting the 

 mouth. This is not the case in pneumothorax. 



TREATMENT. The treatment of pneumothorax can only be a pallia- 

 tive one, and a treatment of symptoms. In many cases, particularly 

 where the volume of the blood is not as yet diminished, as in the trau- 

 matic form of the malady, venesection may be urgently demanded at 

 the outset. We may even be required to repeat the venesection, 

 should the uncompressed lung become so intensely hyperaemic as to be 

 unable to fulfil its function. The pain which arises from straining of 

 the diaphragm and commencing pleuritis should be treated by local 

 blood-letting and cold applications. Opiates are indispensable, for the 

 mitigation of the distress of the patient, and to procure him rest. 



Puncture of the thorax with a fine trocar is indispensable, as a 

 means of relieving the dyspnoea of the patient, although the effect ob- 

 tained is merely palliative. The operation does not benefit the lung 

 of the affected side, but rather the sound lung, when the mediastinum 

 is displaced by pressure of the accumulated ah* and exudation, and 

 hence encroaches upon the unperforated pleura. 



The principles laid down for the treatment of pleuritis are appli 

 cable to the treatment of the more advanced stages of pneumothorax. 



CHAPTER IV. 



TUBERCULOSIS OF THE PLEURA. 



L GRAY miliary tubercle of the pleura occurs almost exclusively in 

 acute miliary tuberculosis, simultaneously with miliary tubercles of the 



