PALS Pharmacology 5 — Questions and Answers
Question 1: A 7-year-old with known asthma is in severe bronchospasm not responding to albuterol. Which PALS medication is considered next?
- Adenosine
- Magnesium sulfate IV (Correct answer)
- Amiodarone
- Lidocaine
Correct answer: Magnesium sulfate IV
IV magnesium sulfate (25–50 mg/kg, max 2 g) is indicated for severe or life-threatening asthma refractory to bronchodilators.
Question 2: Dobutamine is preferred over dopamine in cardiogenic shock because dobutamine primarily:
- Causes peripheral vasoconstriction to raise BP
- Increases cardiac contractility with less tachycardia and vasoconstriction (Correct answer)
- Provides renal-protective vasodilation at low doses
- Blocks beta-2 receptors to reduce myocardial demand
Correct answer: Increases cardiac contractility with less tachycardia and vasoconstriction
Dobutamine is a beta-1 agonist that improves cardiac output without the excessive tachycardia or vasoconstriction seen with higher dopamine doses.
Question 3: A 10-year-old girl receives glucose 0.5–1 g/kg for symptomatic hypoglycemia. What concentration is typically used for IV administration in older children?
- D5W (5%)
- D10W (10%)
- D25W (25%) (Correct answer)
- D50W (50%)
Correct answer: D25W (25%)
D25W (25% dextrose) is typically used for older children, while D10W is preferred for neonates and infants to avoid hyperosmolarity.
Question 4: Which of the following is the correct second dose of adenosine if the first dose fails to convert SVT?
- 0.1 mg/kg (same as first dose)
- 0.2 mg/kg (maximum 12 mg) (Correct answer)
- 0.3 mg/kg (maximum 18 mg)
- 0.5 mg/kg (maximum 6 mg)
Correct answer: 0.2 mg/kg (maximum 12 mg)
If the first dose of adenosine (0.1 mg/kg) fails, the second dose is doubled to 0.2 mg/kg, with a maximum of 12 mg.
Question 5: A child receives epinephrine via endotracheal tube (ETT) because no IV/IO access is available. The correct ETT dose compared to IV is:
- The same dose as IV
- One-tenth the IV dose
- 10 times the IV dose (Correct answer)
- Five times the IV dose
Correct answer: 10 times the IV dose
ETT epinephrine dose is 10 times the IV dose (0.1 mg/kg) because absorption via the lung is unreliable and IV/IO is strongly preferred.
Question 6: Vasopressin is occasionally used in pediatric resuscitation as an alternative to epinephrine. Its mechanism is:
- Beta-1 and beta-2 adrenergic agonism
- Non-adrenergic vasoconstriction via V1 receptors (Correct answer)
- Alpha-2 adrenergic agonism causing sedation
- Calcium channel activation in cardiac muscle
Correct answer: Non-adrenergic vasoconstriction via V1 receptors
Vasopressin causes vasoconstriction through V1 receptor activation independent of adrenergic pathways, which may be effective when catecholamines fail.
Question 7: A child with organophosphate poisoning presents with bradycardia, excessive secretions, and miosis. The antidote targeting muscarinic receptors is:
- Pralidoxime alone
- Atropine (with or without pralidoxime) (Correct answer)
- Physostigmine
- Naloxone
Correct answer: Atropine (with or without pralidoxime)
Atropine reverses muscarinic effects of organophosphate poisoning (SLUDGE syndrome); pralidoxime reactivates acetylcholinesterase and is given concurrently.
PALS Pharmacology 5
A 7-year-old with known asthma is in severe bronchospasm not responding to albuterol.
Which PALS medication is considered next?