PALS - Pediatric Advanced Life Support Tachycardia With a Pulse Questions and Answers

Question 1

A 3-year-old child presents with a regular, narrow-complex tachycardia at a rate of 230/min. The child is irritable but has strong peripheral pulses, a capillary refill of 2 seconds, and normal blood pressure for age. According to the PALS algorithm, which of the following is the most appropriate initial intervention?

Accepted Answer

Attempt vagal maneuvers, such as applying ice to the face.

Answer

For a child with stable supraventricular tachycardia (SVT), the first-line intervention is to attempt vagal maneuvers. If these are unsuccessful, the next step is pharmacologic therapy with adenosine. Synchronized cardioversion is reserved for unstable tachycardia.

Question 2

A 6-year-old child is lethargic with cool, mottled skin. The monitor shows a regular, wide-complex tachycardia with a QRS duration of 0.12 seconds and a rate of 190/min. The blood pressure is 68/40 mmHg. What is the most critical and immediate intervention?

Accepted Answer

Perform immediate synchronized cardioversion.

Answer

This child is exhibiting signs of unstable tachycardia (altered mental status, poor perfusion, hypotension). The PALS algorithm for any unstable tachycardia with a pulse, regardless of QRS width, is immediate synchronized cardioversion. Delaying for other diagnostics or therapies is inappropriate.

Question 3

When analyzing a pediatric ECG, which QRS duration is the threshold that differentiates a narrow-complex from a wide-complex tachycardia according to PALS guidelines?

Accepted Answer

Greater than 0.09 seconds

Answer

In pediatric patients, the PALS guidelines define a wide-complex tachycardia as having a QRS duration greater than 0.09 seconds. A QRS duration of 0.09 seconds or less is considered a narrow-complex tachycardia.

Question 4

A 4-year-old with a history of fever and vomiting presents with a heart rate of 170/min. The ECG shows a narrow QRS complex and visible P waves before each QRS. The heart rate decreases when the child's fever is treated. Which of the following is the most likely rhythm?

Accepted Answer

Sinus Tachycardia

Answer

Sinus tachycardia is a physiologic response to stressors like fever or dehydration. Key features include a heart rate typically less than 180 bpm in a child, the presence of normal P waves, and rate variability that responds to treatment of the underlying cause. SVT typically has a rate over 180 bpm in children and absent or abnormal P waves.

Question 5

You are preparing to administer the initial dose of adenosine to a 10 kg infant with stable SVT that was unresponsive to vagal maneuvers. What is the correct dose and administration technique?

Accepted Answer

1 mg (0.1 mg/kg) as a rapid IV push, followed by a saline flush.

Answer

The initial dose of adenosine for stable SVT in pediatric patients is 0.1 mg/kg, with a maximum first dose of 6 mg. For a 10 kg infant, this is 1 mg. Due to its very short half-life, it must be administered as a rapid IV push immediately followed by a rapid saline flush to ensure it reaches the heart.

PALS - Pediatric Advanced Life Support Practice Test

PALS - Pediatric Advanced Life Support Practice Test

PALS - Pediatric Advanced Life Support Tachycardia With a Pulse Questions and Answers