744 PASSIVE IMMUNIZATION SERUM THERAPY 



Repeating Doses of Serum. It is the general rule to give an intra- 

 spinal injection of serum every day for four days, and then on alternate 

 days until the acute symptoms have subsided, and to resume the treat- 

 ment if an exacerbation or a relapse occurs. In severe fulminant in- 

 fections, and especially if the exudate is thick and only small amounts of 

 serum can be introduced under pressure, it is well to repeat the injection 

 every twelve hours until several doses have been given. Some cases 

 require daily consecutive injections for six or more days; the average 

 case will require from four to six injections if the treatment is begun 

 during the acute stage; in the subacute and chronic cases many more 

 treatments are required. There are two main indications and guides: 



1. The condition of the cerebrospinal fluid. 



2. The clinical condition of the patient. 



1. In most instances the cerebrospinal fluid tends to clear up macro- 

 scopically as the disease improves. This is, however, occasionally 

 misleading, as the fluid may become more turbid as the result of an 

 aseptic meningitis or excitation of a polynuclear leukocytosis due to the 

 serum, while in reality the numbers of meningococci are diminishing 

 and the patient is improving. 



More accurate information is obtained by the microscopic examina- 

 tion of a stained smear of the sediment of the cerebrospinal fluid with- 

 drawn. In fresh acute cases the cocci are numerous and mostly ex- 

 tracellular; improvement is indicated by a diminution in their number, 

 and by the fact that they are mostly intracellular. I generally determine 

 the phagocytic index or the relative proportion of leukocytes that have 

 engulfed cocci and the opsonic index or the relative number of cocci per 

 leukocyte as determined by counting a large number. When many cocci 

 are present, or if they are few in number but mostly extracellular, the 

 indications are to puncture next day, even if the clinical condition of the 

 patient is good and the temperature is lower. The number and position 

 of cocci are, therefore, of more importance as a guide to subsequent 

 injections than is the total number of pus-cells. 



2. .As an indication for repeating the doses of serum the clinical con- 

 dition is of most value when combined with the examination of the 

 cerebrospinal fluid. Occasionally the patient's condition may seem to 

 improve, although the fluid may show numerous cocci, which will sub- 

 sequently aggravate the clinical condition unless the serum is adminis- 

 tered. In favorable cases there is usually a lower temperature the day 

 following an injection, and frequently delirium becomes less marked and 

 there is some return to consciousness. The complexion, which is often 



