EFFECT OF PROLONGED INFUSION OF ISOPROTERENOL ON PLASMA VOLUME AND BLOOD LACTATE AND PYRUVATE IN THE DOG

Abstract

An essential preliminary to therapeutic trial of isoproterenol in the treatment of shock was to ascertain whether prolonged infusion of this drug could of itself cause reduction in plasma volume or increase in blood lactic acid levels. In six dogs the levels of plasma volume and of blood lactate and pyruvate were determined at three dosages, 0.067, 0.13, and 0.33 μg/kg per minute, each maintained for 2 hours, before and after splenectomy. There was a small decrease in plasma volume (average, 4.0%) which was not related to the dosage level. The smalt increases in lactate and pyruvate levels (average, 11.4 and 0.4 mg/100 ml, respectively) were also unrelated to dosage. Excess lactate resulting from infusion (average, 6.0 mg/100 ml) did not differ significantly from zero. It was concluded that these changes were of insufficient magnitude to contraindicate the further trial of isoproterenol in the treatment of shock.