Dopamine Therapy

Introduction to Dopamine Effects

Dopamine exerts different physiological effects at different dosages, with low doses (<2 μg/kg/min) primarily affecting dopaminergic receptors, medium doses (2-10 μg/kg/min) affecting β-adrenergic receptors, and high doses (>10 μg/kg/min) predominantly stimulating α-adrenergic receptors 1

Dopamine stimulates peripheral dopaminergic receptors, causing vasodilation in renal, splanchnic, coronary, and cerebral vascular beds, and may improve renal blood flow, glomerular filtration rate, diuresis, and sodium excretion 1
Dopamine enhances response to diuretic agents in patients with renal hypoperfusion 1

Dopamine stimulates β-adrenergic receptors directly and indirectly, increasing myocardial contractility and cardiac output 1, 2

Dopamine stimulates α-adrenergic receptors, increasing peripheral vascular resistance, causing vasoconstriction, and may be beneficial in hypotensive patients, but can be deleterious in acute heart failure by increasing left ventricular afterload, pulmonary artery pressure, and pulmonary resistance 1, 2

Dopamine may enhance diuresis in combination with diuretics 1
Dopamine is used for hemodynamic support in cardiogenic shock 2
Dopamine increases cardiac contractility and output 1, 2
The European Society of Cardiology recommends administering dopamine at 2-5 mcg/kg/min initially for renal effects, with titration up to 5-10 mcg/kg/min for inotropic effects, and potentially up to 10-20 mcg/kg/min for vasopressor effects based on clinical response 2, 3, 4
Infusion rates >20 mcg/kg/min may result in excessive vasoconstriction, as noted by the American Heart Association 5

Dopamine should be administered preferentially through a central venous catheter, but can be given through a peripheral venous cannula placed in a large bore vein or an intra-osseous cannula when central access is unavailable or staff lacks experience with central lines 6
Standard dilution is 250 mg dopamine in 500 mL of crystalloid solution, and when pumps are unavailable, a drop regulator or micro-infusion set can be used 6
An infusion pump, preferably a volumetric pump, must be used, and arterial blood pressure and heart rate should be measured frequently (every 5-15 minutes) during infusion 6
The infusion site should be frequently checked for signs of extravasation 6
Continuous clinical monitoring and ECG telemetry are required due to increased risk of arrhythmias, particularly at higher doses (>5 mcg/kg/min) which increase the risk of tachycardia, arrhythmias, and α-adrenergic stimulation with vasoconstriction 2, 3

Dopamine is associated with more arrhythmic events (24.1%) compared to norepinephrine (12.4%), as reported in the Intensive Care Medicine guidelines 7
The use of dopamine should be carefully considered due to its potential to cause tachyarrhythmias, decreased urine output, excessive vasoconstriction, and tissue ischemia with extravasation, as warned by the Intensive Care Medicine guidelines 7
If extravasation occurs, treatment with local phentolamine injection (0.1-0.2 mg/kg up to 10 mg diluted in 10 mL of 0.9% sodium chloride) should be considered 8

Norepinephrine may be preferable to dopamine in patients with marked circulatory instability and decompensated shock 5
Norepinephrine is preferred over dopamine for septic shock according to current guidelines from the Surviving Sepsis Campaign, Critical Care Medicine, and Intensive Care Medicine 7, 9, 5
Alternative vasopressors may be preferable in certain situations:

Low-dose dopamine is no longer recommended for renal protection due to lack of beneficial effects, as stated by the Intensive Care Medicine guidelines 7
The American Heart Association recommends that dopamine infusions at rates exceeding 10 mcg/kg/min should be administered through a central venous line due to increased risk of tissue necrosis and vasoconstriction with peripheral administration 5
Peripheral administration of dopamine is acceptable at low to medium doses (1-10 mcg/kg/min) but requires caution and close monitoring, especially with small distal veins 5