726 PASSIVE IMMUNIZATION SERUM THERAPY 



If any nerves are exposed, antitoxin should be injected into them. The 

 injection of 1500 units of antitoxin is generally advised as the first prophy- 

 lactic dose. 



2. From the fact that tetanus antitoxin is one of the albuminous 

 constituents of horse serum that are foreign to the human system, in the 

 human being the antitoxin is rapidly eliminated in from eight to ten 

 days after the injection is administered. Knorr has found, as the result 

 of animal experiments, that by the sixth day only one-third, and by the 

 twelfth day only one-fiftieth, of the optimum quantity remained in the 

 blood. Hence it is important, if antitoxin is to prove useful, that it should 

 be present in the system for two or three weeks after receipt of the injury, 

 especially as it cannot be determined when the tetanus bacillus first gained 

 access to the wound. There should be a second intramuscular injection 

 of 1000 units of antitoxin about the end of the first week, and perhaps a 

 similar dose at the end of the second week. While certain individuals may 

 develop serum sickness, no dangerous symptoms have been observed 

 to result from the use of tetanus antitoxin. 



3. If the surgeon is first consulted several days after the injury has 

 been inflicted, the wound should be opened and dressed as previously 

 described, and, in addition to the intramuscular injection of 1500 units 

 of antitoxin in the neighborhood of the wound, it will be good practice 

 to inject an additional 5000 or 10,000 units intravenously. It requires 

 at least twenty-four hours for the antitoxin to be absorbed from the 

 subcutaneous tissues, and immediate neutralization of any toxin present 

 in the blood may mean a great deal from the standpoint of prognosis 

 if tetanus should develop. 



Treatment of Tetanus. While the great value of antitetanic serum 

 as a preventive is unquestioned, as a specific cure it has fallen short of 

 the earliest expectations. It has been shown experimentally, however, 

 that tetanus antitoxin may save the lives of animals already manifesting 

 the symptoms of an otherwise fatal intoxication. In order to accomplish 

 this result the serum must be given in doses several hundred times the 

 size required merely for protective purposes, and it must be injected 

 within a short time from twenty-four to thirty-six hours after the 

 onset of the tetanus. Furthermore, statistics favor the use of the serurn 

 as the mortality has been reduced from 80 to 85 per cent, to 60 or 65 per 

 cent, in cases receiving serum treatment. 



The recognition of the natural limitations of the serum treatment of 

 tetanus will serve to emphasize the importance of its proper adminis- 

 tration. A large number of units must be given, and must be injected 



