ACLS Emergency Pharmacology 5 — Questions and Answers
Question 1: Which antiarrhythmic is most appropriate for stable monomorphic VT with preserved LV function?
- Digoxin 0.5 mg IV over 30 min
- Procainamide 20–50 mg/min IV (Correct answer)
- Magnesium 2 g IV push
- Atropine 1 mg IV push
Correct answer: Procainamide 20–50 mg/min IV
Procainamide 20–50 mg/min IV (max 17 mg/kg) is a first-line agent for stable monomorphic VT with preserved ejection fraction.
Question 2: After ROSC, a patient is hypotensive with MAP 55 mmHg. Which vasopressor infusion is recommended first-line?
- Vasopressin 0.04 units/min
- Epinephrine 0.1–0.5 mcg/kg/min
- Norepinephrine 0.1–0.5 mcg/kg/min (Correct answer)
- Phenylephrine 100–200 mcg/min
Correct answer: Norepinephrine 0.1–0.5 mcg/kg/min
Norepinephrine is a first-line vasopressor for post-cardiac arrest hypotension due to its potent alpha-1 vasoconstriction with mild beta-1 support.
Question 3: A patient has pulseless electrical activity (PEA) from suspected tension pneumothorax. What drug should be given while preparing needle decompression?
- Epinephrine 1 mg IV immediately (Correct answer)
- Atropine 1 mg IV immediately
- Amiodarone 300 mg IV immediately
- No drugs — only mechanical intervention helps
Correct answer: Epinephrine 1 mg IV immediately
Epinephrine 1 mg IV/IO every 3–5 minutes is given per ACLS protocol for PEA while reversible causes like tension pneumothorax are corrected.
Question 4: What is the correct endotracheal dose of epinephrine if IV/IO access cannot be established?
- 0.5 mg diluted in 5–10 mL NS
- 1 mg diluted in 5–10 mL NS
- 2–2.5 mg diluted in 5–10 mL NS (Correct answer)
- 5 mg diluted in 10 mL NS
Correct answer: 2–2.5 mg diluted in 5–10 mL NS
The endotracheal dose of epinephrine is 2–2.5 times the IV dose (2–2.5 mg) diluted in 5–10 mL of sterile water or NS.
Question 5: A patient with SVT receives adenosine 6 mg without effect. What is the appropriate next step?
- Repeat adenosine 6 mg immediately
- Give adenosine 12 mg IV rapid push (Correct answer)
- Switch to amiodarone 150 mg IV over 10 min
- Perform synchronized cardioversion at 50 J
Correct answer: Give adenosine 12 mg IV rapid push
If the initial 6 mg adenosine dose does not convert SVT, the second dose is 12 mg IV rapid push.
Question 6: Which drug interaction must be considered before giving adenosine to a patient on theophylline?
- Theophylline enhances adenosine's effect, requiring half the dose
- Theophylline blocks adenosine receptors, requiring a higher dose (Correct answer)
- Theophylline has no interaction with adenosine
- Theophylline prolongs adenosine's half-life, increasing toxicity
Correct answer: Theophylline blocks adenosine receptors, requiring a higher dose
Theophylline competitively blocks adenosine receptors, so patients on theophylline may require a higher adenosine dose to terminate SVT.
Question 7: In opioid-induced cardiac arrest, what modification to the standard ACLS algorithm is recommended?
- Give double-dose epinephrine and skip naloxone
- Administer naloxone 0.4–2 mg IV/IO/IM as soon as possible (Correct answer)
- Replace amiodarone with naloxone for rhythm control
- Skip epinephrine and use only naloxone
Correct answer: Administer naloxone 0.4–2 mg IV/IO/IM as soon as possible
Naloxone 0.4–2 mg IV/IO/IM should be given as soon as possible in suspected opioid-induced cardiac arrest alongside standard ACLS.
ACLS Emergency Pharmacology 5
Which antiarrhythmic is most appropriate for stable monomorphic VT with preserved LV function?