PALS - Pediatric Advanced Life Support Tachycardia With a Pulse Questions and Answers — 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?
- Perform synchronized cardioversion at 0.5 J/kg.
- Attempt vagal maneuvers, such as applying ice to the face. (Correct answer)
- Administer adenosine 0.1 mg/kg rapid IV push.
- Administer amiodarone 5 mg/kg IV over 20 minutes.
Correct answer: Attempt vagal maneuvers, such as applying ice to the face.
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?
- Obtain a 12-lead ECG to confirm the diagnosis.
- Administer a 20 mL/kg bolus of isotonic crystalloid.
- Consult pediatric cardiology before proceeding.
- Perform immediate synchronized cardioversion. (Correct answer)
Correct answer: Perform immediate synchronized cardioversion.
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?
- Greater than 0.12 seconds
- Less than 0.08 seconds
- Greater than 0.09 seconds (Correct answer)
- Exactly 0.10 seconds
Correct answer: Greater than 0.09 seconds
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?
- Supraventricular Tachycardia (SVT)
- Ventricular Tachycardia
- Atrial Flutter
- Sinus Tachycardia (Correct answer)
Correct answer: Sinus Tachycardia
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?
- 1 mg (0.1 mg/kg) as a rapid IV push, followed by a saline flush. (Correct answer)
- 2 mg (0.2 mg/kg) as a slow IV push over 1 minute.
- 0.5 mg (0.05 mg/kg) as a rapid IV push.
- 6 mg (standard adult dose) as a slow IV infusion.
Correct answer: 1 mg (0.1 mg/kg) as a rapid IV push, followed by a saline flush.
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.
Question 6: A 7-year-old child in the PICU develops an unstable narrow-complex tachycardia. You are preparing for synchronized cardioversion. What is the recommended initial energy dose?
- 4 J/kg
- 10 J/kg
- 0.5 to 1 J/kg (Correct answer)
- 20 J/kg
Correct answer: 0.5 to 1 J/kg
For unstable tachycardia requiring synchronized cardioversion, the initial recommended energy dose is 0.5 to 1 J/kg. If the first shock is unsuccessful, the dose may be increased to 2 J/kg for a subsequent attempt. Higher energy doses are used for defibrillation in cardiac arrest.
PALS - Pediatric Advanced Life Support Tachycardia With a Pulse Questions and Answers
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?