Which statement correctly describes the structure of the cardiac arrest algorithm in ACLS?

Which statement correctly describes the structure of the cardiac arrest algorithm in ACLS?

• A. The algorithm has two pathways - one for VF/pVT and one for PEA/Asystole.
• B. PEA and asystole are shockable rhythms.
• C. Epinephrine is given after every second cycle of CPR.
• D. The first step is to start chest compressions immediately without assessing rhythm.

Answer: (A)

The key idea is that the ACLS cardiac arrest algorithm splits into two pathways based on the detected rhythm: a shockable pathway for VF or pulseless VT, and a non-shockable pathway for PEA or asystole. When the rhythm is shockable, defibrillation is the immediate priority to terminate the chaotic electrical activity, followed by CPR and rapid reassessment. When the rhythm is non-shockable, you don’t defibrillate; instead you push for high-quality CPR, early vasopressor support (epinephrine at regular intervals), and investigation and treatment of reversible causes, continuing CPR and reassessment until the rhythm becomes shockable or ROSC occurs. This branching structure is what guides why defibrillation is used for VF/pVT but not for PEA/asystole. The other statements don’t fit this structure. PEA and asystole are not shockable rhythms, so they are not treated with defibrillation. Epinephrine is given at intervals of about every 3–5 minutes, not after every second CPR cycle. And the algorithm doesn’t skip rhythm assessment entirely; recognizing the rhythm first determines which pathway to follow.

The key idea is that the ACLS cardiac arrest algorithm splits into two pathways based on the detected rhythm: a shockable pathway for VF or pulseless VT, and a non-shockable pathway for PEA or asystole. When the rhythm is shockable, defibrillation is the immediate priority to terminate the chaotic electrical activity, followed by CPR and rapid reassessment. When the rhythm is non-shockable, you don’t defibrillate; instead you push for high-quality CPR, early vasopressor support (epinephrine at regular intervals), and investigation and treatment of reversible causes, continuing CPR and reassessment until the rhythm becomes shockable or ROSC occurs. This branching structure is what guides why defibrillation is used for VF/pVT but not for PEA/asystole.

The other statements don’t fit this structure. PEA and asystole are not shockable rhythms, so they are not treated with defibrillation. Epinephrine is given at intervals of about every 3–5 minutes, not after every second CPR cycle. And the algorithm doesn’t skip rhythm assessment entirely; recognizing the rhythm first determines which pathway to follow.