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Difficulty: HardCardiovascular System

A 62-year-old man suddenly collapses while walking in the hospital corridor. He is unresponsive, pulseless, and apneic. A code blue is activated, and high-quality cardiopulmonary resuscitation (CPR) is immediately initiated. The crash cart arrives, and the defibrillator pads are applied. The cardiac monitor displays coarse ventricular fibrillation. Assuming the patient remains pulseless and the rhythm remains unchanged throughout the resuscitation, arrange the following management steps in the correct chronological sequence according to Advanced Cardiac Life Support (ACLS) guidelines.

  1. 1Deliver an initial unsynchronized biphasic shock
  2. 2Immediately resume cardiopulmonary resuscitation for 2 minutes and establish intravenous access
  3. 3Deliver a second unsynchronized biphasic shock
  4. 4Administer intravenous epinephrine 1 mg
  5. 5Administer intravenous amiodarone 300 mg

Answer

The correct chronological sequence is: 1) Deliver an initial unsynchronized biphasic shock, 2) Immediately resume cardiopulmonary resuscitation for 2 minutes and establish intravenous access, 3) Deliver a second unsynchronized biphasic shock, 4) Administer intravenous epinephrine 1 mg, and 5) Administer intravenous amiodarone 300 mg.
The ACLS protocol for Ventricular Fibrillation follows a strict chronological sequence: First, deliver a shock. Second, immediately resume CPR for 2 minutes and obtain IV access. Third, check rhythm and deliver a second shock for persistent VF. Fourth, resume CPR and administer epinephrine 1 mg. Fifth, deliver a third shock (omitted from these options but chronologically occurring before the next medication). Sixth, resume CPR and administer amiodarone 300 mg.

Step-by-Step Solution

1
Identify the initial rhythm and required intervention.
The rhythm is ventricular fibrillation (VF), which is a shockable rhythm requiring immediate defibrillation (initial unsynchronized shock).
Early defibrillation is the most critical determinant of survival in VF arrest.
2
Determine the action immediately following the first shock.
CPR must be resumed immediately for 2 minutes, and IV/IO access should be established.
Chest compressions maintain coronary and cerebral perfusion; pausing for a rhythm check immediately after a shock severely reduces survival odds.
3
Determine the sequence after the first 2-minute CPR cycle.
A rhythm check reveals persistent VF, necessitating a second unsynchronized shock.
The algorithm dictates a rhythm check and subsequent shock (if indicated) every 2 minutes.
4
Identify the correct timing for epinephrine administration.
Epinephrine 1 mg is administered during the CPR cycle that follows the second shock.
In shockable rhythms, epinephrine is delayed until after the second shock, unlike in non-shockable rhythms (PEA/Asystole) where it is given immediately.
5
Identify the correct timing for amiodarone administration.
Amiodarone 300 mg is given after the third shock.
Antiarrhythmics are indicated only for refractory VF/pVT that has not responded to multiple shocks and a vasopressor.

Key Concept

In the ACLS Cardiac Arrest Algorithm for shockable rhythms (VF/pVT), defibrillation is the highest priority. Epinephrine is delayed until after the second unsuccessful shock, and antiarrhythmics (amiodarone) are reserved for refractory arrhythmias persisting after the third shock.
Estimated Time:1m 30s
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Topics

Cardiovascular System

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