The Influence of Adrenergic Blocking Agents on Metabolic Events in Hemorrhagic Shock in the Dog

Dibenamine hydrochloride administered intravenously 30 min. after the onset of hemorrhage in anesthetized dogs, in which hemorrhagic hypotension (43–45 mm. Hg for 90 min.) of the Wiggers' type had been produced, resulted in an increased rate of survival as compared to that of untreated controls. The mean increase in plasma amino nitrogen and the percentage decrease in total arterial oxygen transport were significantly less in the Dibenamine-treated group. In animals treated with Dibenamine or Dibenzyline hydrochloride 85 min. after hemorrhage as compared to untreated controls, there were no significant differences in survival rate, plasma amino nitrogen, lactate, pyruvate, lactate/pyruvate ratio, bicarbonate content, or blood pH. The arterial oxygen transport, however, was significantly higher after than before treatment and also in the postinfusion period was higher in the two treated groups than in the untreated group. In these two late-treated groups, however, the plasma amino nitrogen increase was significantly greater in the fatalities than in the survivors during both the hypotensive and postinfusion periods. In the untreated group, differences between survivors and fatalities appeared only after the reinfusion of the withdrawn blood.