RESPIRATORY REGULATION OF THE CO, CAPACITY 
OF THE BLOOD. 
II. LOW LEVELS OF CO; AND ALKALI INDUCED BY ETHER. THEIR 
PREVENTION AND REVERSAL. 
By YANDELL HENDERSON anv H. W. HAGGARD. 
aan the Physiological Laboratory, Yale Medical School, New Haven.) 
(Received for publication, Detanner 31; 1917.) 
In the light of present knowledge it appears probable that 
many, perhaps most, of the functional disturbances induced by 
anesthesia are due to the production of an abnormal CO, ca- 
pacity (alkaline reserve) in the blood, or to deeper effects of 
which the CO, capacity is an index. 
At present such effects are generally interpreted as “acidosis.” 
Our observations show that, at least under ether, they are of a 
very different origin. 
Morriss! has shown that in patients under ether a lowering of 
the alkaline reserve of the plasma occurs. On the basis of some 
preliminary experiments on dogs Prince and the authors? have 
verified Morriss’ observation and have obtained results indi- 
cating that the effect is due to the respiratory excitement in- 
duced by ether. An abnormally great amount of CO, is venti- 
lated out of the blood by the excessive breathing and the CO, 
content is thus lowered. Sometimes when this blowing off has 
been very rapid the result is failure of respiration: apnea vera. 
When the blowing off is less rapid but is prolonged another 
change occurs which (as Prince first pointed out to us) is of a 
compensatory character. This consists (as set forth in general 
terms in the first paper of this series) in a decrease of the CO2- 
combining power (alkaline reserve) of the blood. The simplest 
supposition upon which to explain it is that when the alkalinity 
1 Morriss, W. H., J. Am. Med. Assn., 1917, Ixviii, 1391. 
2 Henderson, Y., Prince, A. L., and Haggard, H. W., J. Am. Med. Assn., 
1917, lxix, 965. 
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