DIAGNOSTIC APPLICATIONS OF THE BLOOD-COUNT 223 



the variation in the red corpuscles. Thus, in a case of severe 

 sepsis of any sort the red corpuscles and haemoglobin may fall 

 enormously in a few days. This is a very valuable test for 

 puerperal fever. Under ordinary circumstances the amount of 

 blood lost at parturition should not lower the corpuscles below 

 4,000,000, and if a count greatly below this is found in a few days' 

 time, there having been no severe haemorrhage in the meantime, 

 the diagnosis of septic infection is probable, whatever be the 

 numbers of the leucocytes ; if at a later date the numbers are 

 lower still, the diagnosis is almost certain. The haemoglobin 

 may fall 10 per cent, per day, or even more in a severe 

 case. 



Conversely, a rise in the number of red corpuscles and hsemo- 

 globin is a good sign when the existence of septic infection is 

 certain, whatever be the clinical condition ; a cessation of the fall 

 is good also, but to a less extent. (Beware, however, of mistaking 

 a concentration of the blood from diarrhoea or profuse vomiting 

 for a true rise.) As an example I may quote the case of a patient 

 under Dr. Hayes in King's College Hospital, in whom about a 

 fortnight after parturition there were 1,306,000 reds, 26 per cent, 

 haemoglobin, 13,400 leucocytes, of which 87 per cent, were 

 polynuclears. Here 2,700,000 reds had been lost in two weeks, 

 indicating a very severe sepsis. Her condition appeared desperate, 

 yet in a week the reds had increased to 2,750,000, in a fortnight 

 more to 3,760,000, when for the first time she showed clinical 

 improvement. In nine days more they had reached 4,000,000, 

 and the patient was out of danger. Here a good prognosis was 

 given solely on the blood-count. 



In these cases a great diminution or total disappearance of the 

 eosinophiles is a bad sign, their reappearance a good one. 



2. Suppuration. — Where the sepsis is localized and not so severe, 

 so that a limited focus of suppuration occurs, there is a leucocy- 

 tosis which, in round figures, exceeds 20,000, and the increase is 

 mainly due to a rise in the polynuclears. Various writers give 

 different figures as that above which pus is indicated : some take 

 15,000, which I find to be reached fairly often when there is no 

 pus ; others 25,000, which is frequently not reached when sup- 

 puration has occurred. The number 20,000 has been taken as 

 the result of a considerable amount of experience of all forms of 

 suppuration, and will prove a correct indication in at least 90 per 

 cent, of all cases. It is especially useful in appendicitis, in which 



