STUDIES OF OXYGEN IN THE VENOUS BLOOD : IV. DETERMINATIONS ON FIVE PATIENTS WITH INCOMPENSATED CIRCULATORY DISTURBANCES.

1. A report is made of 103 determinations of the oxygen unsaturation of the venous blood of five patients with incompensated heart diseases. 2. Values for the oxygen unsaturation within normal limits were found only under two circumstances: (a) in a stage of full compensation, and (b) in a stage of incompensation where the symptoms were rapidly lessening. 3. Values above the upper normal extreme were met with under three circumstances: (a) during incompensation, (b) during compensation just before the clinical symptoms of incompensation had developed, and (c) at times in patients with auricular fibrillations in a condition of complete and stable compensation. 4. A comparison has been drawn between the directly found value for the oxygen unsatilration and the values for the oxygen consumption calculated from previous experiments by the writer on the blood flow (minute volume of the heart), in patients with similar clinical conditions. A close agreement existed. 5. It seems probable from our experience with patients under digitalis therapy that the oxygen unsaturation affords, an objective criterion of the positive effect of the therapy.