There is ample experimental evidence that inhalation of carbon dioxid, properly diluted with air or oxygen, should be a therapeutic agent of great potency. In fact, however, aside from the indirect use of this gas in the rebreathing methods of anesthesia, particularly with nitrous oxid, inhalation of carbon dioxid is not used in surgery. Likewise in internal medicine it is not employed, except perhaps in the Nauheim bath treatment of cardiac conditions; and here there is no agreement as to whether or not the inhalation is a factor.
This lack of use is the more striking when we note the present deficiency in therapeutic agents to stimulate breathing, and the great need for one; for carbon dioxid is Nature's own stimulant to the respiratory center.1
On the circulation its influence is equally important— particularly on the venous return to the right heart. It is the insufficiency of this return
HENDERSON Y, HAGGARD HW, COBURN RC. THE THERAPEUTIC USE OF CARBON DIOXID AFTER ANESTHESIA AND OPERATION. JAMA. 1920;74(12):783-786. doi:10.1001/jama.1920.02620120009003