Depressed Response to Intravenous Sympathicomimetic Agents in Humans During Acidosis

¹ The Departments of Surgery and Physiology, Univ. of Minnesota Medical school.

1. Healthy human subjects were given intravenous epinephrine during eupnea (blood pH 7.37), during 10 per cent carbon dioxide inhalation (blood pH 7.23), and during voluntary hyperventilation (blood pH 7.61). Arterial pressor and ECG changes following identical doses of epinephrine were minimal during acidosis and maximal during alkalosis. During respiratory alkalosis one subject exhibited ventricular extrasystoles and transient absence of T waves following epinephrine.

2. Clinical patients with septicemia and shock who had become refractory to pressor agents were studied. During this refractory period, arterial blood studies revealed severe metabolic acidosis with arterial blood pH as low as 7.06. Following the partial or complete correction of this acidosis by intravenous administration of molar sodium lactate, blood pressure response to sympathicomimetic agents increased.