AUTOSERUM THERAPY 839 



with cerebrospinal fluid, so that no air will be injected. The serum is 

 then poured into the syringe, and permitted to flow slowly by means of 

 gravity into the subarachnoid space. At times it is necessary to insert 

 the plunger of the syringe to inject the last 5 c.c. of fluid. It is im- 

 portant that the larger part of the serum should be injected by gravity, 

 and if the rubber tubing is not more than 40 cm. long, the pressure cannot 

 be higher than 400 mm. Usually the serum flows in easily even under 

 a lower pressure. By the gravity method the danger of suddenly in- 

 creasing the intraspinous pressure to the danger-point, such as might 

 occur with rapid injection with a syringe, is avoided (Swift and Ellis). 



The method of injection by gravity is described on p. 746. In the 

 absence of a suitable manometer for estimating cerebrospinal fluid pres- 

 sure the blood-pressure may be taken as a guide; in any event the serum 

 should be injected slowly. 



McCaskey consumes about six or seven minutes in administering 

 the salvarsan intravenously, and advises withdrawing the blood twenty 

 minutes thereafter, instead of waiting an hour in order to secure a 

 larger quantity of the drug in the serum. He injects 15 c.c. of serum in 

 50 per cent, dilution intraspinally, and has not observed any increased 

 irritative effects. 



Swift and Ellis inject the serum in strengths of 50 to 60 per cent, or 

 even higher in patients who do not exhibit reactions following the injec- 

 tion of 40 per cent, serum. Boggs and Snowden withdraw from 75 to 

 100 c.c. of blood one hour after the salvarsan injection, secure the serum, 

 heat it at 56 C. for one-half hour, and inject the undiluted serum in a 

 dose equal to the amount of fluid withdrawn, whether this is only a few 

 or as much as 30 c.c. 



The method employed by Marinesco and Minea, 1 whereby the 

 patient's serum is salvarsanized in vitro, is not to be regarded as the 

 same as the method of Swift and Ellis. The first-named investigators 

 sought to administer larger doses of salvarsan by this method, but in a 

 preliminary report, covering the treatment of 20 cases receiving injec- 

 tions every seven to eight days, the results are said to have been disap- 

 pointing. The recent unfortunate outcome of this form of therapy in 

 the County Hospital of Los Angeles is ascribed to the oxidation and 

 consequent toxicity of the neosalvarsan as a result of allowing the sal- 

 varsanized serum to stand for twenty hours before injecting it. 



After-treatment. The patient should be kept in bed for twenty-four 

 hours and the foot of the bed should be elevated for part of this time. 

 1 Bull, de 1'Acad. de Med., 1914, Ixxvii, No. 7. 



