Pediatric Advanced Life Support (PALS) Practice Test

Atropine is recognized for its ability to increase heart rate by blocking the effects of the vagus nerve on the heart. However, in certain circumstances, particularly when administered in high doses or too rapidly, atropine can actually lead to paradoxic bradycardia. This phenomenon occurs because initially, atropine may cause a transient increase in vagal tone or a direct effect on the heart that can result in slower heart rates.

In pediatric patients, the vagal response can be quite pronounced, and the fewer receptors available at higher doses can lead to complications such as bradycardia. Thus, understanding the dosing and administration of atropine is crucial in clinical practice to avoid this adverse effect.

Other medications listed, such as epinephrine, dopamine, and lidocaine, do not typically result in bradycardia; rather, they are used for their positive chronotropic (increasing heart rate) effects or for arrhythmias but lack the paradoxical outcome associated with atropine when it is mishandled in dosing or administration.