General Surgery 17 



in mind that the greater the concentration the quicker to develop 

 and the more widespread the anesthesia. The maximum dose which 

 can be employed hypodermically without causing any constitutional 

 disturbance must not exceed one-sixteenth of a grain per pound 

 bodyweight. On mucous surfaces this amount may be slightly ex- 

 ceeded, particularly in parts possessing much density of mucosa, 

 such as the vagina where absorption does not readily occur. 



The anesthetic effect develops in from two to eight minutes and 

 lasts from fifteen to sixty minutes and covers an area about an inch in 

 diameter. It may be intensified by dissolving the cocaine in a quarter 

 per cent c. p. sodium chloride or a five per cent phenol solution. It 

 may also be considerably prolonged by the addition of one-fifth the 

 amount of morphine. There is an additional advantage in combin- 

 ing the last named drug in that it possesses antidotal power over 

 cocaine. Cocaine is most conveniently carried in the form of 

 tablets of definite strength as prepared by the manufacturing phar- 

 macists. X 



Solutions are applied to the conjunctiva and other mucous 

 surfaces by means of the camel's hair brush or medicine dropper. 

 In this manner some slight anesthetic eflfect may be obtained on the 

 skin itself in parts where the latter is thinnest. 



To properly anesthetize the skin in the area of operation, the 

 point of the needle should not be immediately thrust through the 

 skin as in administering an ordinary hypodermic injection but must 

 first stop within the skin which should receive a few drops of the 

 fluid. When an extended area is to be operated on, a series of in- 

 jections should be made, the point of the needle being reinserted 

 within and near the periphery of the wheal produced by the pre- 

 vious injection. In the case of a tumor, a circle of injections can 

 be made to surround the area. 



Eucaine is preferred to cocaine by some practitioners. Its 

 anesthetic effect is somewhat slower to develop but it lasts longer 

 and is just as complete and is also less toxic and may be safely ad- 

 ministered in doses of one-half grain per pound bodyweight. 



Eudrenine is a combination of cocaine and adrenalin. It pos- 

 sesses an advantage over cocaine alone in that the adrenalin dimin- 

 ishes vascularity of the part and thereby hinders absorption of the 

 cocaine, besides tending to render minor operations bloodless. 



3 



