PALS Tachycardia 5

Question 1

A 6-year-old with SVT is being monitored; the team cannot obtain IV access. What alternative route can adenosine be given?

Accepted Answer

Intraosseous (IO)

Answer

Intraosseous (IO) access is an acceptable alternative to IV for adenosine administration when IV access cannot be established rapidly.

Question 2

Which of the following best describes the mechanism of action of adenosine in terminating SVT?

Accepted Answer

Transiently blocks AV nodal conduction, interrupting re-entry circuits

Answer

Adenosine acts on A1 receptors to transiently block AV nodal conduction, which interrupts the re-entry circuit responsible for most SVT.

Question 3

A 4-year-old with SVT converts to sinus rhythm after adenosine but then reverts to SVT 30 seconds later. What does this most likely indicate?

Accepted Answer

The dose was adequate but the underlying trigger needs treatment

Answer

Recurrence of SVT after successful adenosine conversion often indicates a persistent underlying trigger (e.g., fever, electrolyte abnormality) or an accessory pathway; the next dose should be doubled or an alternative agent considered.

Question 4

What is the maximum single dose of adenosine in a pediatric patient?

Accepted Answer

12 mg

Answer

The maximum single dose of adenosine in children is 12 mg, regardless of weight, to prevent excessive side effects.

Question 5

Which sign most reliably indicates that a child with tachycardia has progressed to cardiovascular compromise requiring immediate intervention?

Accepted Answer

Altered mental status and poor perfusion despite tachycardia

Answer

Altered mental status combined with poor perfusion (weak pulses, mottling, prolonged cap refill) indicates end-organ compromise and mandates immediate treatment.

PALS - Pediatric Advanced Life Support Practice Test

PALS - Pediatric Advanced Life Support Practice Test

PALS Tachycardia 5