ACLS Provider: Course

Cardiac Arrest Algorithm

The ACLS Cardiac Arrest Algorithm provides a systematic approach to managing patients experiencing cardiac arrest, a critical medical emergency characterized by the sudden cessation of effective cardiac function. The algorithm emphasizes the importance of rapid recognition, high-quality cardiopulmonary resuscitation (CPR), and appropriate interventions based on the identified cardiac rhythm.

Recognizing Cardiac Arrest:

  • No Pulse: The absence of a palpable pulse in a large artery (carotid or femoral) is a primary indicator of cardiac arrest.
  • Unresponsive and Not Breathing (or Only Gasping): The patient will be unresponsive to stimuli and will not have normal respirations. They may exhibit agonal gasps, which are infrequent, irregular, and ineffective breaths. These should be considered a sign of cardiac arrest.

Shockable Rhythms:

  • Ventricular Fibrillation (VF): VF is a chaotic, disorganized electrical activity in the ventricles, resulting in ineffective or absent cardiac contractions.
  • Pulseless Ventricular Tachycardia (pVT): pVT is a rapid, regular ventricular rhythm with wide QRS complexes, but without a palpable pulse, indicating ineffective cardiac output.

Non-Shockable Rhythms:

  • Asystole: Asystole represents the complete absence of electrical activity in the heart, resulting in a flatline or near-flatline ECG tracing.
  • Pulseless Electrical Activity (PEA): PEA is characterized by organized electrical activity on the ECG but without a corresponding palpable pulse, indicating a mechanical failure of the heart to contract effectively.

ACLS Cardiac Arrest Algorithm:

  1. Initiate CPR and provide oxygen. Attach defibrillator or monitor: These are the immediate first steps upon recognizing cardiac arrest.
  • CPR: Begin high-quality CPR immediately, focusing on effective chest compressions (rate of 100–120/min, depth of at least 2 inches, allowing full chest recoil, and minimizing interruptions).
  • Oxygen: Administer supplemental oxygen as soon as possible.
  • Attach Defibrillator/Monitor: Attach a defibrillator or cardiac monitor to assess the patient's heart rhythm.
  1. If the rhythm is shockable (VF/pVT):
  • Deliver 1 Shock: Deliver a single defibrillation shock at the appropriate energy level (based on the defibrillator type and manufacturer recommendations).
  • Resume CPR Immediately for 2 Minutes: Immediately after the shock, resume high-quality CPR for 2 minutes. This is crucial for maintaining coronary and cerebral perfusion.
  • Administer Epinephrine Every 3–5 Minutes: Epinephrine (1 mg IV/IO) is administered every 3–5 minutes during the resuscitation effort to enhance cardiac contractility and vasoconstriction.
  • Consider Amiodarone for Refractory VF/pVT: If VF/pVT persists after multiple defibrillation attempts and epinephrine administration, consider administering an antiarrhythmic medication such as amiodarone (300 mg IV/IO bolus, then 150 mg IV/IO if needed). Lidocaine is an alternative if amiodarone is unavailable.
  1. If the rhythm is non-shockable (asystole/PEA):
  • Continue CPR and Administer Epinephrine Every 3–5 Minutes: High-quality CPR and epinephrine administration are the primary interventions for non-shockable rhythms.
  • Reassess Rhythm Every 2 Minutes: Reassess the patient's rhythm every 2 minutes during CPR. If a shockable rhythm develops, proceed to the shockable rhythm protocol.
  • Identify and Treat Reversible Causes (H's and T's): It is crucial to actively search for and treat potential reversible causes of cardiac arrest, using the "H's and T's" mnemonic:
    • H's: Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia
    • T's: Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary or coronary)

Key Interventions Throughout the Algorithm:

  • Ensure High-Quality CPR at All Times: Maintaining high-quality CPR is paramount throughout the resuscitation effort. Minimize interruptions to chest compressions, ensure adequate compression depth and rate, and allow full chest recoil.
  • Identify and Treat Reversible Causes: Actively searching for and treating reversible causes is crucial for improving the chances of successful resuscitation and patient survival.