A discussion of the care of patients who are about to be carried through an operation on the heart should include a consideration of the heart beat or, more precisely, a consideration of restoration of the heart beat. I need scarcely state the reason for this inclusion, because every one knows that the coordinated contractions of the heart can be lost during or after an operation on this organ. If one considers restoration of the heart beat, one must consider also respiration and the oxygen required to sustain life, because all three of these are joined together to do one thing, namely, to supply oxygen to the cells. This is shown in the accompanying chart.
PRESERVATION OF VITAL PROCESSES
Oxygen, Respiration and Circulation.
—The distribution of oxygen cannot be interrupted longer than a few minutes without destruction of the respiratory center and other brain centers. It is known that the