The Cardiac Arrest Algorithm is a structured, evidence-based approach to managing patients in cardiac arrest. It emphasizes the importance of high-quality CPR, early defibrillation (when applicable), and effective medication administration.
Why It’s Important:
Standardized approach improves survival outcomes. Ensures rapid recognition and treatment of cardiac arrest. Incorporates early defibrillation, medication therapy, and post-resuscitation care.
INITIAL STEPS: IMMEDIATE RESPONSE
Check for responsiveness – Tap the patient and shout. Assess breathing and pulse (simultaneously for no more than 10 seconds). If the patient is unresponsive and has no normal breathing (or only gasping):
Start chest compressions IMMEDIATELY:
Compression-to-ventilation ratio (if no advanced airway): 30:2 Compression rate: 100-120 per minute Compression depth: At least 2 inches (5 cm) in adults Minimize interruptions – Pauses <10 seconds!
If an advanced airway is placed (ETT/LMA): Give 1 breath every 6 seconds (10 breaths per minute). Continue chest compressions continuously without pausing for ventilations.
High-quality CPR is the MOST important factor in cardiac arrest survival!
RHYTHM ANALYSIS: DIFFERENTIATING CARDIAC ARREST RHYTHMSThe monitor will display one of four cardiac arrest rhythms:
| Rhythm Type | Definition |
|---|---|
| Ventricular Fibrillation (VF) | A chaotic, disorganized electrical activity in the ventricles. |
| Pulseless Ventricular Tachycardia (pVT) | A rapid, regular heartbeat from the ventricles, but no pulse. |
| Asystole | Complete absence of electrical activity (flatline). |
| Pulseless Electrical Activity (PEA) | Electrical activity is present, but no palpable pulse. |
Determine whether the rhythm is SHOCKABLE or NON-SHOCKABLE.
SHOCKABLE RHYTHMS: VF/pVT (DEFIBRILLATION REQUIRED) Deliver an IMMEDIATE Shock (Defibrillation)
Resume CPR IMMEDIATELY (for 2 minutes) after shock
Reassess Rhythm & Deliver Additional Shocks (if indicated)
Administer Epinephrine (1 mg IV/IO) every 3-5 minutes
Administer an Antiarrhythmic (If VF/pVT persists after multiple shocks)
Key Takeaway: Continue cycles of CPR → Shock → Medications → Rhythm Check until ROSC or termination of resuscitation.
NON-SHOCKABLE RHYTHMS: Asystole & PEA (NO DEFIBRILLATION) 
Continue High-Quality CPR (for 2 minutes).
Administer Epinephrine 1 mg IV/IO every 3-5 minutes.
Identify & Treat Reversible Causes (Hs & Ts).
Reassess Rhythm Every 2 Minutes
Key Takeaway: In non-shockable rhythms, CPR and identifying the cause (Hs & Ts) are the main priorities!
REVERSIBLE CAUSES OF CARDIAC ARREST: THE “Hs & Ts” Cardiac arrest is often caused by reversible conditions that MUST be identified and treated.
| H Causes | Description |
|---|---|
| Hypovolemia | Severe blood or fluid loss. |
| Hypoxia | Low oxygen levels. |
| Hydrogen Ion (Acidosis) | Severe metabolic or respiratory acidosis. |
| Hyperkalemia/Hypokalemia | Potassium imbalances affecting cardiac function. |
| Hypothermia | Core body temperature too low (<30°C or 86°F). |
| T Causes | Description |
|---|---|
| Tension Pneumothorax | Air trapped in the chest collapses a lung. |
| Tamponade (Cardiac) | Fluid around the heart restricts pumping. |
| Toxins (Overdose, Poisoning) | Drug overdoses, especially opioids. |
| Thrombosis (Pulmonary or Coronary) | Blood clots in the lungs (PE) or heart (MI). |
Key Takeaway: If you do not treat the underlying cause, CPR alone will not be effective!
POST-RESUSCITATION CARE (AFTER ROSC) If the patient regains a pulse (Return of Spontaneous Circulation – ROSC), immediate post-arrest care is critical!
Optimize Ventilation & Oxygenation
Manage Blood Pressure
Consider Targeted Temperature Management (TTM)
Identify & Treat the Underlying Cause
Key Takeaway: Post-cardiac arrest care improves neurological function and long-term survival!
SUMMARY OF THE CARDIAC ARREST ALGORITHM SHOCKABLE RHYTHMS (VF/pVT)
Shock immediately CPR for 2 minutes Reassess rhythm → If shockable, shock again! Epinephrine (1 mg IV/IO every 3-5 min) Antiarrhythmics (Amiodarone or Lidocaine) if needed
NON-SHOCKABLE RHYTHMS (Asystole/PEA) CPR for 2 minutes Epinephrine (1 mg IV/IO every 3-5 min) Treat reversible causes (Hs & Ts) Reassess rhythm every 2 minutes
Continue cycles until ROSC or termination of resuscitation.
FINAL TAKEAWAYS: MASTERING CARDIAC ARREST MANAGEMENT High-quality CPR is the cornerstone of survival. Shock promptly for VF/pVT – defibrillation saves lives! Epinephrine is essential for both shockable and non-shockable rhythms. Identify and treat reversible causes (Hs & Ts). Post-resuscitation care optimizes outcomes after ROSC.
Takeaway: The Cardiac Arrest Algorithm provides a life-saving, structured approach—every healthcare provider must master it!
