Low-dose dopamine in severe right heart failure and chronic obstructive pulmonary disease.

OBJECTIVE

To describe the beneficial effects of low-dose dopamine infusion (2-5 micrograms/kg/min) in a patient with severe cor pulmonale complicating chronic obstructive pulmonary disease (COPD).

CASE SUMMARY

A 53-year-old woman with severe cor pulmonale and generalized edema complicating COPD received low-dose dopamine to stabilize blood pressure and, perhaps, improve cardiac output. Low-dose dopamine also improved her renal function and enhanced the diuretic response to furosemide therapy.

DISCUSSION

Previous studies of dopamine in such patients were reviewed. Both dopamine infusion (4 micrograms/kg/min) and oral administration of its precursor, L-dopa, can increase the cardiac output, decrease pulmonary vascular resistance, and enhance oxygen delivery in patients who are stable with cor pulmonale secondary to COPD. In patients with COPD during acute respiratory failure, high-dose dopamine (10 micrograms/kg/min) has been shown to increase the diaphragmatic blood flow and contraction. Low-dose dopamine also has been reported to be useful in patients with congestive heart failure or cirrhosis of the liver.

CONCLUSIONS

Low-dose dopamine is useful in the acute management of patients with severe cor pulmonale complicating COPD because of the drug's beneficial effects on blood pressure, cardiac output, renal perfusion, natriuresis, and diuresis. Low-dose dopamine also may enhance the natriuretic and diuretic response to loop diuretics, decrease pulmonary vascular resistance, and enhance oxygen delivery.