To the Editor:—
In your editorial of July 2, 1960, page 1032, "Use of Air Pressure to Speed up Blood Transfusion," mention is made of the intravenous administration of calcium. I would like to offer a note of caution, since calcium given intravenously would be dangerous to a patient who has been digitalized. In many instances such patients are very ill, and, if they have been receiving digitalis, calcium should not be used. It is well known that calcium given intravenously depresses the cardiac pacemaker and increases the excitability of ventricular muscle. Some deaths have been reported when calcium was administered intravenously to patients who had been receiving digitalis.