CATHETEEISM OF THE UEETHKA. 557 



reaches the ischial space the stylet must be withdrawn in order to 

 avoid the diiS&culty of bending the catheter over the curve formed 

 at that point in the urethra. At this moment a gentle but firm 

 and. steady pressure upon the end of the instrument (easily felt 

 at the ischial arch), made by an assistant bending it forward, will, 

 with a little careful pushing, effect its entrance into the bladder. 

 This will, of course, become known at once by the cessation of 

 the resistance, and by the escape of the urine which may be con- 

 tained in the bladder. 



The removal of the institmient is effected by simply drawing 

 it carefully from the passage. 



Sometimes simple pressure over the- ischial arch is insufficient, 

 and the bending of the instrument into the proper direction is to 

 be made through the rectum, and hence the indication of ha\dng 

 that organ well emptied before j^roceeding to the oi^eration. 



The indication of great caution in this operation is suggested 

 by a consideration of the fact that (if the canal should chance to 

 be of unusually narrow diameter or its walls softened by disease) 

 there is sometimes danger of forming false passages, by punctur- 

 ing the mucous membrane, and forcing the catheter into the 

 erectile tissue which surrounds the urethra. This is an incident 

 which, however, can be avoided by removing the stylet from the 

 canula before its introduction into the urethra, the canula itself 

 being terminated by a j^erforated oval bulb, perfectly smooth, and 

 thus incapable of inflicting injury. 



In Catheterizing Females, a small catheter may be and is 

 sometimes used, but as a rule, the metallic instrument is prefer- 

 able, the conditions of the method, the shortness of the passage 



CT 



Fig. 468.— Female Catheter. 



and its comparatively large diameter, with the facility with which 

 it can be entered, rendering the metallic on all accoimts more 

 ehgible than the composition or the rubber tube. 



The instrument, being lubricated with oil or vaseline, the oper- 

 ator, opening the vulva with the left hand, introduces his right, 

 holding the instrument, into the vagina, and carries it forward to 

 the meatus urinarius, which he can feel at about six or seven 



