So now let’s take a closer look at dopamine.
Dopamine is a naturally occurring catecholamine.
It has direct alpha and beta adrenergic effects depending on the dose.
Now when a medium dose is given, like 5-10 mcg per kg per minute, dopamine acts directly
on beta1 receptors which causes increased myocardial contractility and increased heart
rate.
When used in doses greater than 10 mcg per kg per minute alpha receptors are stimulated,
which results in an increase in systemic vascular resistance, in other words vasoconstriction.
Dopamine can be a very effective drug in treating hypotension with signs and symptoms of shock.
Dopamine is typically used as a second line drug for symptomatic bradycardia after atropine.
Now dopamine may cause tachyarrhythmias and excessive vasoconstriction and should be used
with caution in patients who are suffering from cardiogenic shock with associated symptoms
of Congestive Heart Failure.
Now it’s important to correct hypovolemia with volume replacement before we initiate
dopamine therapy.
The adult dosage for dopamine should be administered via IV and it’s most common infusion rate
is 2 to 20 mcg per kg per minute.
We want to be sure to titrate the dosage and drip rate to patient’s response slowly and
carefully.