4bb OPERATIONS ON THE KESPIEATORY APPARATUS. 



trachea that the index finger could scarcely be inserted into the 

 passage. 



THOKACENTESIS. 



The usual intention of this operation is the removal from the 

 thoracic cavity of suppurative matter {empyema) or blood or se- 

 rous fluid, by puncturing the walls of the chest. It is indicated 

 in hydrothorax and in some traumatisms of the chest, and when- 

 ever there is a large collection of bloody or other fluid in the thorax; 

 in all cases, in fact, where the ordinary forms of treatment have 

 failed to relieve the patient thus affected. Although extensively 

 performed in human surgery, w^here the advantages and facilities 

 of operating are so many and so manifest, it has naturally proved 

 less beneficial to veterinary patients. And still, though probably 

 in the majority of the cases in which it has been employed the 

 rehef which has followed it has been of only a temporary charao- 

 ' ter, and served only to prolong briefly the life of the animal sub- 

 jected to it, some few cases are on record in which it has given 

 very excellent results. The researches of St. Cyr have, moreover, 

 demonstrated that the operation is perfectly harmless, contrary to 

 the opinion formerly held, and that a large proportion of its fail- 

 ures to effect recovery are due to the fact that its application had 

 been too long postponed to justify a reasonable expectation of 

 success ; when, in fact, it had been deferred imtil the accumula- 

 tion of fluid had already become too abundant, and the pleural 

 membranes had already assumed the condition of a tendency to 

 pyogeny. 



On this point, Peuch and Toussaint remark that if the punc- 

 ture is made when only the lower thii'd of the cavity is full, and 

 if after the evacuation of the hquid a diluted solution of tincture 

 of iodine is injected into the pleural sac, as is done in human 

 surgery, perhaps more satisfactory residts might be realized. 

 Our own -view, however, is that the disposition of the pleura and 

 of the ca\dties, which they form, would scarcely justify the in- 

 jection. 



The instruments required are a straight or convex bistomy, 

 and a small trocar, straight or slightly curved. Keul has invented 

 a paracento-injector trocar (Fig. 434), which is used for both the 

 puncture and the subsequent injection of the medical compounds. 

 The use of the aspirator (Dieulafoy) is also recommended. 



