ADMINISTRATION OF SALVARSAN AND NEOSALVARSAN 865 



the vein and the saline solution or water from the tubing the nozzle ol 

 the latter is fitted into the needle quickly and securely while the latter 

 is held firmly in the vein. The appearance of bulging at the side of the 

 vein and the occurrence of pain indicate that the needle has not been 

 properly inserted. In this event the clamp should be fastened, the 

 needle withdrawn, the tourniquet adjusted, and another vein punctured. 

 It is useless to attempt to enter the same vein at the same point. 



4. The introduction of a full dose of salvarsan or neosalvarsan will 

 usually take from ten to twenty minutes or thereabouts. If the flow is 

 retarded, the needle may be turned gently and slightly so as to change 

 the relation of the bevel to the wall of the vein. 



5. When salt solution forms the first portion of the injection, no 

 harm has been done if perivascular infiltration occurs. This method 

 gives added assurance to the operator; indeed, it should never be 

 omitted when salvarsan is being injected, and it is a good general rule to 

 have the first portion of the injection consist of normal salt solution. 



6. After the requisite dose has been injected, a few cubic centimeters 

 of salt solution are again permitted to flow into the vein, so that the tub- 

 ing and needle are washed free from salvarsan, and at no time does the 

 drug come in contact with the tissues. 



7. The needle is then quickly withdrawn, and the site of the punc- 

 ture sealed with collodion and cotton after the iodin has been removed 

 by washing with alcohol. 



Intravenous Administration of Salvarsan in Concentrated Solution. 

 While animal expermients have shown us that concentrated solutions 

 of salvarsan are not markedly toxic, the administration of concentrated 

 solutions to persons appears to increase the chances of disagreeable 

 after-effects. This is particularly true if the concentrated solution is 

 injected quickly, which is the natural tendency of the physician when 

 all is working smoothly. 



In preparing a concentrated solution, 20 c.c. of hot, sterile, freshly 

 distilled water are placed in a small Erlenmeyer flask or cylinder and the 

 drug added in small amounts followed by brief shaking, until all has 

 been added and dissolved. The clear solution is now neutralized by the 

 addition of a 15 per cent, solution of caustic soda in exactly the same manner 

 as in the preparation of the dilute solution. The physician must never 

 omit this step', the intravenous injection of a concentrated and acid solution 

 of salvarsan is most dangerous and has resulted in fatalities. 



The solution, which should be filtered through sterile gauze or paper, 



is now taken up into a sterile 20- or 30-c.c. syringe and air dispelled; 

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