DIUKESIS 67 



urethra about level of top of symphysis. Tie thread in loose running noose 

 round urethra. Lifting urethra by thread in left hand, cut obliquely half through 

 urethral duct (PI. V, fig. 2) with fine sharp scissors about 3 mm. distal to 

 thread-ligature. 



The glass urethral cannula (PI. V, fig. 3) armed with rubber tube, clamped 

 by clip, filled with Ringer fluid at 37° C, and lying ready to right hand, is then 

 inserted into opening in urethra and passed up so that its free end lies within 

 bladder above the sphincter. Cannula should be 20-30 mm. to neck for this. 

 Tie cannula in position by drawing tight and securing the thread ; the tie must 

 be quite tight or cannula will slip. 



Cover pubic incision, &c., with warm moist swab. 



B. Exposure of external jugular vein and insertion of cannula. Turn to neck : 

 carefully lay bare right ext. jug. vein (PL V, fig. 5). To expose the vein, feel 

 through the skin for the triangular hollow between the sternal and clavicular 

 origins of the sterno-cleidomastoid muscle (see exerc. VI, § VII). Make a 

 skin incision about 4 cm. long from nearly as far forward as the level of the 

 cricoid cartilage along the median edge of the cleidomastoid. 



Pass fine silk in loose running noose round vein, about 4 cm. above top of 

 sternum. Pass similarly another about 6 mm. nearer sternum, and another 

 about 6 mm. nearer still to the sternum. The position of these ligatures must 

 depend upon the side-branches of the vein which you expose. The distal and 

 proximal threads should include between them a length of the vein free from 

 side-branches : see figure. Occlude the vein by means of the third (proximal) 

 ligature by allowing a pair of artery-forceps or light weight to drag slightly on 

 it. Tie tight the first (distal) ligature. Lift the vein slightly by the thread of 

 the first ligature just tied. Open vein by oblique incision half through it just 

 distal to the second (middle) ligature. Insert glass cannula into proximal end of 

 vein and tie it in by tightening and securing silk ligature (middle ligature). 

 Fill cannula with warm Ringer fluid, excluding air. 



IV. Arrange (PI. V, fig. 4) a small dish between hind-limbs and lead a rubber 

 tube from urethral cannula so that its free end, cut obliquely to give a drip- 

 point, overhangs the floor of dish, and fix tube in that position with a little 

 modelling clay. 



Probably there will be no urinary flow ; the blood-pressure is so low that 

 the urinary secretion is in abeyance. Wash out bladder by injecting 30-40 c.c. 

 Ringer-Locke at 37° with glass syringe ; note that most of what you put in 

 does not run out again ; the postural tonus of the bladder adjusts itself to the 

 new quantity. Expel some of the fluid from the bladder by light pressure on 

 the viscus through abdominal wall. Continue observation for urinary flow for 5'. 



K 2 



