ACLS Pulseless 5 — Questions and Answers
Question 1: A patient in refractory VF is suspected to have hypomagnesemia. Which drug and dose is recommended?
- Magnesium sulfate 1–2 g IV over 5–20 minutes (Correct answer)
- Magnesium sulfate 4 g IV bolus
- Magnesium oxide 400 mg PO
- Magnesium chloride 500 mg IO
Correct answer: Magnesium sulfate 1–2 g IV over 5–20 minutes
Magnesium sulfate 1–2 g IV is indicated for torsades de pointes (polymorphic VT) and suspected hypomagnesemia-related VF.
Question 2: How is the adequacy of CPR best monitored in an intubated patient during cardiac arrest?
- Pulse oximetry waveform
- Arterial blood gas pH trending
- Continuous waveform capnography (PETCO2) (Correct answer)
- Heart rate on the cardiac monitor
Correct answer: Continuous waveform capnography (PETCO2)
Continuous waveform capnography provides real-time feedback on CPR quality; rising PETCO2 toward ≥10–20 mmHg indicates improving perfusion.
Question 3: A patient with cardiac tamponade goes into pulseless electrical activity. What is the definitive treatment?
- Immediate defibrillation at 200 J
- Emergency pericardiocentesis (Correct answer)
- Epinephrine infusion at 20 mcg/min
- Synchronized cardioversion at 150 J
Correct answer: Emergency pericardiocentesis
Emergency pericardiocentesis relieves the tamponade and is the definitive treatment for PEA caused by cardiac tamponade.
Question 4: Which finding would most strongly suggest that ongoing resuscitation efforts should be terminated?
- PETCO2 consistently 12 mmHg at 10 minutes
- No ROSC after 20+ minutes of ACLS with all reversible causes addressed (Correct answer)
- Rhythm changes from VF to asystole after second shock
- Initial PEA with a rate of 60 bpm
Correct answer: No ROSC after 20+ minutes of ACLS with all reversible causes addressed
Failure to achieve ROSC after prolonged ACLS with no reversible causes identified is a reasonable basis for considering termination of resuscitation.
Question 5: What is the correct ventilation rate during CPR for an adult patient with an advanced airway in place?
- 1 breath every 3–4 seconds (15–20/min)
- 1 breath every 6 seconds (10/min) (Correct answer)
- 2 breaths every 30 compressions
- 1 breath every 10 seconds (6/min)
Correct answer: 1 breath every 6 seconds (10/min)
Once an advanced airway is placed, deliver 1 breath every 6 seconds (10 breaths/min) without interrupting continuous chest compressions.
Question 6: During a cardiac arrest, sodium bicarbonate administration is most clearly indicated in which scenario?
- Asystole unresponsive to epinephrine
- Suspected hyperkalemia or pre-existing metabolic acidosis (Correct answer)
- VF that persists after two defibrillation attempts
- PEA with a heart rate of 80 bpm
Correct answer: Suspected hyperkalemia or pre-existing metabolic acidosis
Sodium bicarbonate may be beneficial in cardiac arrest with known or suspected hyperkalemia and in patients with severe pre-existing metabolic acidosis.
Question 7: A patient achieves ROSC after 18 minutes of CPR and remains comatose with no purposeful movement. Current ACLS guidelines recommend which temperature target?
- Active warming to 38–39°C
- Targeted temperature management (TTM) at 32–36°C for at least 24 hours
- Maintain normothermia (36–37.5°C) with aggressive fever prevention (Correct answer)
- Induce hypothermia to 28–30°C for neuroprotection
Correct answer: Maintain normothermia (36–37.5°C) with aggressive fever prevention
Current evidence supports preventing fever (>37.5°C) in post-arrest comatose patients; strict TTM at 33°C vs. 36°C showed similar outcomes, and fever prevention is the primary goal.
ACLS Pulseless 5
A patient in refractory VF is suspected to have hypomagnesemia.
Which drug and dose is recommended?