504 PUNCTURE FOR EMPYEMA. 



removing pleuritic effusion gradually, points to the use of trocars 

 of moderate calibre. In carnivora, and to a less extent in horses 

 and oxen, rapid discharge of large quantities of fluid is liable to produce 

 sudden changes of intra-thoracic pressure, determining grave dis- 

 turbance of circulation, which may occasion not only fresh exudation, 

 but pulmonary bleeding, syncope, or even sudden death. The danger 

 is greatest in left-side effusion, by which the heart has been pushed 

 towards the right side. Frequently, in horses, the whole of the 

 fluid is removed at one operation, and if the chest refills the operation 

 is repeated. Some practitioners advise removing only 10 to 15 

 pints at one time, and a further quantity some hours later, or on 

 the following day. From the position of the tapping, the complete 

 evacuation of the pleural sac is impossible ; but even if it were possible, 

 as already pointed out, it would not be desirable. In too many 

 cases further effusion soon takes place. When sufficient fluid is 



Fig. .388. — Special trocar and cannula. The second limb is provided with a 

 long rubber tube, allowing the instrument to be used as an aspirator. 



believed to have been removed, the stilette, previously cleansed, 

 is again introduced, and the cannula carefully removed, the wound 

 rinsed with a disinfectant, powdered with iodoform, and closed with 

 wound gelatine, or collodion, or a suture may be inserted. The 

 benefits of paracentesis mainly result from its modifying intra-thoracic 

 pressure, relieving compression of the lungs, and improving conditions 

 for absorption. 



Thoracic puncture for empyema, or for abscess in the lungs, is 

 not often employed, and rarely proves successful. The procedure 

 is the same as for pleuritic effusion, particular attention being paid 

 to antiseptic precautions. Exploratory punctures may sometimes 

 be needful for diagnosis. 



After complete removal of the contents, it may be desirable to 

 wash out the pleural cavity. For this purpose, towards the roof 

 of the chest a new opening is made, through which weak disinfectants, 

 warmed to blood heat, are introduced, and afterwards withdrawn 

 through the cannula placed in the lower opening. Hoffmann employed 



