CARDIAC ARREST ALGORITHM

The Cardiac Arrest Algorithm provides a structured approach to managing patients in cardiac arrest. It emphasizes the importance of high-quality CPR, early defibrillation (when indicated), and the administration of appropriate medications.

INITIAL STEPS

1. Assess the Patient: Check for responsiveness and breathing. If the patient is unresponsive and not breathing normally (or only gasping), activate the emergency response system (e.g., call 911 or your local emergency number).

2. Start CPR: Begin chest compressions immediately. The compression-to-ventilation ratio is 30:2 if no advanced airway is in place. Once an advanced airway (e.g., endotracheal tube) is placed, provide continuous chest compressions at a rate of 100-120 per minute with one breath every 6 seconds (10 breaths per minute).

3. Attach Monitor/Defibrillator: As soon as available, attach a cardiac monitor/defibrillator to assess the patient’s heart rhythm.

RHYTHM ANALYSIS

The monitor will display one of four rhythms:

• Ventricular Fibrillation (VF): A chaotic, disorganized electrical activity in the ventricles.
• Pulseless Ventricular Tachycardia (pVT): A rapid, regular heartbeat originating in the ventricles, but without a pulse.
• Asystole: The absence of electrical activity in the heart.
• Pulseless Electrical Activity (PEA): Electrical activity is present on the monitor, but there is no palpable pulse.

SHOCKABLE RHYTHMS (VF/pVT)

If the rhythm is VF or pVT:

1. Deliver a Shock: Deliver one electrical shock using the defibrillator.
2. Resume CPR: Immediately resume CPR for 2 minutes, starting with chest compressions.
3. Reassess Rhythm: After 2 minutes of CPR, reassess the heart rhythm.
4. If the rhythm is still shockable, deliver another shock and repeat the cycle of CPR and rhythm checks.
5. Administer Epinephrine: Administer epinephrine 1 mg IV/IO every 3-5 minutes.
6. Consider an Antiarrhythmic: If the rhythm remains refractory to defibrillation, consider administering amiodarone (300 mg IV/IO first dose, 150 mg IV/IO second dose) or lidocaine (1-1.5 mg/kg IV/IO first dose, 0.5-0.75 mg/kg IV/IO second dose).

NON-SHOCKABLE RHYTHMS (Asystole/PEA)

If the rhythm is asystole or PEA:

1. Continue CPR: Continue high-quality CPR for 2 minutes.

2. Administer Epinephrine: Administer epinephrine 1 mg IV/IO every 3-5 minutes.

3. Search for and Treat Reversible Causes (Hs and Ts): Consider and address potential reversible causes of cardiac arrest. These can be remembered using the mnemonic “Hs and Ts”:

   • Hs:
     • Hypovolemia: Low blood volume.
     • Hypoxia: Lack of oxygen.
     • Hydrogen ion (acidosis): Excessive acidity in the blood.
     • Hyper/hypokalemia: Abnormal potassium levels in the blood.
     • Hypothermia: Low body temperature.
   • Ts:
     • Tension pneumothorax: Air trapped in the chest cavity, collapsing the lung.
     • Tamponade (cardiac): Fluid buildup around the heart, preventing it from pumping effectively.
     • Toxins: Poisoning.
     • Thrombosis (pulmonary or coronary): Blood clots in the lungs or coronary arteries.

POST-RESUSCITATION CARE

After return of spontaneous circulation (ROSC), focus on post-cardiac arrest care, including:

• Optimizing ventilation and oxygenation
• Managing blood pressure
• Targeted temperature management
• Identifying and treating the underlying cause of the cardiac arrest

The Cardiac Arrest Algorithm provides a clear and systematic approach to managing cardiac arrest. Healthcare professionals should be thoroughly familiar with this algorithm to ensure effective and timely intervention.