Hemodynamic effects of Gd-DTPA administered via rapid bolus or slow infusion: a study in dogs

The hemodynamic effects of rapid (10 sec) versus slow (1 min) IV injection of Gd-DTPA were compared in normal, pentobarbital-anesthetized mongrel dogs. Hypertonic mannitol and isotonic saline were used as equiosmotic and equivolumetric controls. Two dose levels of Gd-DTPA were administered: 0.1 mmol/kg and 0.5 mmol/kg, corresponding to dose volumes of 0.2 and 1.0 ml/kg, respectively. The rapid injection of a high dose (0.5 mmol/kg) produced a transient decrease in arterial blood pressure (21 mm Hg, p less than .001), which returned to control values within 1 min after the injection. Slow IV infusion at this high dose had no statistically significant hemodynamic effects. There were no statistically significant effects of the lower dose (0.1 mmol/kg) administered as a bolus or by infusion, nor of the saline or osmotic control solutions. These results suggest that acute hemodynamic effects of Gd-DTPA are not observed at clinically relevant doses and the vasodilation observed at a higher dose may result from a direct action of the contrast agent.