STUDIES OF OXYGEN IN THE VENOUS BLOOD. 
I. TECHNIQUE AND RESULTS ON NORMAL INDIVIDUALS. 
By CHRISTEN LUNDSGAARD. 
(From the Hospital of The Rockefeller Institute for Medical Research.) 
(Received for publication, October 17, 1917.) 
The term oxygen, content of the venous blood has been used 
in the literature in two senses. It is applied to the amount of 
oxygen in the blood in the right heart and also the amount in the 
venous blood of some organ or group of organs. 
In the blood of the right side of the heart the oxygen can be 
determined by using the lungs plus a bag (1-5) or a part of the 
lungs (6) as a tonometer. The air in the lungs is brought to 
equilibrium with the blood gas and a sample of the air is analyzed. 
In animals, samples of. blood can be drawn through a cannula 
introduced into the heart. 
Samples of venous blood from single organs can be obtained 
in animals when the technical difficulties can be overcome. 
Extensive studies have been made in the last few years, partic- 
ularly by Barcroft and his associates (7).! oo 
In adults the superficial veins of the limbs and neck, partic- 
ularly of the arm (vena mediana) are the only sources from which 
venous blood can be obtained.? That means that only blood 
coming from a limited region, consisting chiefly of muscles, can 
be studied. Consequently the field of investigation is limited. 
The conditions can be varied voluntarily only to a small extent. 
The results have to be interpreted chiefly in an empirical way 
and by means of general clinical cbservation. In spite, however, 
of limitations and a priori theoretical difficulties in interpreting 
1 For bibliography see Barcroft (7). | 
2 In the Pediatric Department of Johns Hopkins Hospital venous blood 
is obtained by puncturing the sinus sagittalis in babies. This method 
makes it possible to obtain venous blood without stasis from children 
where the superficial veins are too small. 
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