How a dose of Dopamine works

Explain how a dose of dopamine works to help treat Mr. P’s heart failure. Mr. P., 82 years of age, is receiving dopamine at a dose of 5 mcg/kg/min for heart failure. Mr. P’s vital signs are as follows:

Blood pressure:150/88 mm Hg, the Pulse rate: 92 beats/min, Respiration rate:16 breaths/min. While at rest, he has no shortness of breath but has had some dyspnea when getting up to the bedside commode. He has edema in his lower legs rated as 2+ edema.

What is dopamine’s duration of action and half-life?

How does knowing the information about dopamine affect your plan of care?