Advanced Cardiovascular Life Support (ACLS) Practice Exam

For a patient with sinus bradycardia of 40/min where atropine is ineffective, what is the appropriate dose of dopamine?

1. 1 to 5 mcg/kg per minute

2. 2 to 10 mcg/kg per minute

3. 5 to 15 mcg/kg per minute

4. 10 to 20 mcg/kg per minute

The correct answer is: 2 to 10 mcg/kg per minute

Dopamine is used as a second-line treatment for symptomatic bradycardia when atropine is ineffective. The appropriate dosing for dopamine in this context is crucial for achieving the desired pharmacological effects, particularly in increasing heart rate and improving cardiac output. When administering dopamine for bradycardia, the recommended dosing range is typically between 2 to 10 mcg/kg per minute. At this dosage range, dopamine acts primarily on beta-adrenergic receptors, which can lead to increased heart rate and improved myocardial contractility. At lower doses (2 to 5 mcg/kg per minute), dopamine primarily stimulates dopaminergic receptors, while at higher doses (beyond 10 mcg/kg per minute), it begins to exert significant alpha-adrenergic effects which can lead to increased vascular resistance and could potentially worsen hemodynamics in a bradycardic patient. This careful balance is why the choice of 2 to 10 mcg/kg per minute is appropriate. It provides adequate heart rate stimulation without excessively increasing vascular resistance, which is particularly important in emergency cardiovascular situations where bradycardia can compromise hemodynamic stability. Thus, administering dopamine within this specific range ensures effective management of bradycardia while minimizing risks associated with