692 
PA THOLOGY: UNDERBILL AND RINGER Proc. N. A. S. 
BLOOD CONCENTRATION CHANGES IN INFLUENZA 
By Frank P. Underhill and Michael Ringer 
Department of Experimental Medicine, School of Medicine, Yale University 
Communicated by L. B. Mendel, October 22, 1920 
From the pathological viewpoint influenza presents a striking simi- 
larity to the respiratory compHcations induced by the lethal war gases, 
chlorine, phosgene and chlorpicrin. In both conditions there are two 
features that stand out prominently, namely, pulmonary edema and a 
pneumonic process. In both, edema may be regarded as the response 
to an intense inflammatory reaction resulting in a loss of the normal 
protective mechanism of the upper respiratory tract, thus allowing bac- 
terial invasion of the lung. 
It has been shown by UnderhilP and his associates that in acute poi- 
soning by the lethal war gases edema of the lungs is accompanied by 
marked changes in the concentration of the blood, which, according to 
Underbill, is the chief factor contributing to death. Blood concentra- 
tion means a failing circulation, an inefficient oxygen carrier, oxygen 
starvation of the tissues, fall of temperature, and finally suspension of 
vital activities. 
During the recent epidemic an opportunity was afforded to study a 
series of cases of influenza in the New Haven Hospital through the co- 
operation of Dr. George Blumer and his staff. The investigation with 
these subjects enables us to state definitely that in the fulminating cases 
of influenza there is a marked increase in the concentration of the blood re- 
sembling closely that observed in the acute stages of gas poisoning. Death in- 
variably followed a marked increase in blood concentration. Again, of the 
cases that recovered in not a single instance was there evidence of a significant 
increase in blood concentration. 
Therefore it is quite apparent that both physiologically and pathologi- 
cally there is a marked resemblance between influenza and war gas 
poisoning. Blood concentration in both conditions is an important 
factor in the cause of death. Blood concentration is incompatible with 
continued existence. 
Under proper conditions, blood concentration changes in influenza 
may be followed by accurate hemoglobin estimations. 
A method of treatment evolved for acute gas poisoning has been ap- 
plied with success in a few cases of influenza. The method consists in 
the maintenance of blood concentration as near the normal level as possi- 
ble by venesection and fluid introduction. 
^ Underbill, The Lethal War Gases: Physiology and Experimental Treatment, Yale 
University, 1920. 
