Prevention of Blood Clotting. 



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184 (1362) 



The prevention of blood clotting by Dakin's sodium hypochlorite 



solution. 



By T. S. Githens and S. J. Meltzer. 



[From the Department of Physiology and Pharmacology of the Rocke- 

 feller Institute for Medical Research.] 



It has been shown by Austin and Taylor that Dakin's solution 

 dissolves necrotic tissue in wounds and washes away blood clots. 

 Sweet has stated that the dressing of wounds with this solution 

 favored hemorrhage from them. We made experiments to deter- 

 mine whether the solution prevented the clotting of blood in vitro 

 and wish to record some of the facts observed. 



We found that Dakin's solution of sodium hypochlorite added 

 to blood in vitro was able to prevent clotting. If blood of a dog 

 is drawn directly into Dakin's solution in the proportion of one 

 part of Dakin's to ten of blood, clotting is usually prevented en- 

 tirely. In a few instances such blood showed the formation of 

 small, soft clots after standing several days. In no case was there 

 any sign of clotting when as much as 1.5 c.c. of Dakin's to 10 c.c. 

 of blood were used, even after standing as much as four weeks. 

 There is a slight difference between the blood of different species; 

 thus cat blood is prevented from clotting by rather smaller amounts 

 than are required for the dog, while rabbit blood requires rather 

 more and guinea-pig blood needs about 4 c.c. for each 10 of blood. 



Dakin's solution on standing is said to lose its effectiveness as 

 an antiseptic and its toxicity when injected intraperitoneally. 

 Its power to prevent clotting was found to be reduced to about 

 half in a week and it remained at this point for several weeks. 

 Thus of a certain sample 0.8 c.c. were required to prevent clotting 

 in 10 c.c. of blood when fresh; 1.4 c.c. when 10 days old and 1.5 

 c.c. when 40 days old. 



Blood preserved from clotting by Dakin's solution is not af- 

 fected by calcium salts but is readily caused to clot by tissue ex- 

 tracts. When the Dakin-blood mixture is fresh the clot formed on 

 addition of tissue extract, forms promptly and becomes firm, but 



