Hemodynamic effects of combined digoxin and dopamine administration in postoperative patients with cardiac...

In 10 patients with postoperative cardiac dysfunction which required dopamine for inotropic and hemodynamic support, we observed the cardiovascular effects of short-term digoxin administration. The average dosage of dopamine was 7.45 micrograms/kg per minute and was maintained while the patients were given 1 mg of digoxin over 8 hours. The dosage of dopamine was then tapered over the next 4 hours. We observed a significant increase in the cardiac index (4 hours) and a reduction in the heart rate (8 hours) before the dopamine dosage was reduced. After a reduction in dopamine dosage to 2.28 micrograms/kg per minute, these effects persisted. No significant changes were noted in systemic vascular resistance or pulmonary artery diastolic pressure during digoxin administration. These results indicate that the inotropic effects of dopamine and digoxin are additive when given in combination and that digoxin can be used to significantly reduce the dopamine dosage in patients with postoperative cardiac failure. Thus, the combination of an acute inotropic agent, dopamine, and a chronic inotropic agent, digoxin, appears to be clinically useful in postoperative cardiac dysfunction.