Effect of Sodium Citrate on Blood Coagulation. 105 



from subcutaneous tissues, give notoriously inaccurate results. 

 With the present patient on several occasions, blood so obtained 

 and examined in capillary tubes coagulated in from ten to forty 

 minutes at times when the venous blood was known to coagulate 

 in one to two hours. 



The injection of 150 cubic centimeters of normal blood from 

 another person mixed with 0.3 gram of sodium citrate shortened 

 the coagulation time of the patient's blood taken ten minutes 

 after the transfusion from one hour fifteen minutes (beginning 

 coagulation at fifty minutes) to seventeen minutes (beginning 

 coagulation twelve minutes). Twenty-four hours later, however, 

 the coagulation time was found to be practically the same as 

 before the transfusion, namely one hour fifteen minutes for com- 

 plete coagulation (beginning coagulation forty-five minutes). 

 The coagulation time of blood obtained nine days later was one 

 hour, thirty-five minutes (beginning coagulation one hour and 

 twenty minutes). 



The intravenous injection of 0.6 gram of sodium citrate (20 cubic 

 centimeters of 3 per cent, citrate solution) shortened the coagulation 

 time of the blood obtained ten minutes after the injection from 

 one hour thirty-five minutes (one hour twenty minutes beginning 

 coagulation) to twenty-five minutes. Forty-eight hours later, 

 however, the coagulation time was found to have been lengthened 

 out to two hours and fifty minutes (beginning coagulation one 

 hour and twenty-five minutes). 



At this time when the coagulation of the blood was at its 

 longest, an experiment was made to see whether there was any 

 immediate effect of citrate on coagulation after the citrate was 

 injected into a muscle. The result was negative; the coagulation 

 time taken thirty-five minutes after the intragluteal injection of 

 0.72 grams of sodium citrate was two hours and fifty-three minutes 

 (beginning coagulation two hours). The coagulation time of the 

 patient was not determined again for two weeks when it was 

 found to have returned to approximately the same level as had 

 been usual before the citrate injections, namely one hour (be- 

 ginning coagulation forty-five minutes). 



The citrate injections and the blood transfusion produced no 

 ill effects whatever. The patient continued to have occasional 



