AHA ACLS Cardiac Arrest Algorithm

The AHA ACLS Cardiac Arrest Algorithm is a step-by-step guideline developed by the American Heart Association to manage adult cardiac arrest effectively. It helps healthcare providers deliver timely, evidence-based interventions during life-threatening emergencies.

The Advanced Cardiopulmonary Life Support (ACLS) algorithm covers critical actions like high-quality CPR, rhythm analysis, defibrillation, medication administration, and identifying reversible causes. Its goal is to improve survival and neurological outcomes through organized, team-based care.

Step-by-Step Action to Manage ACLS Cardiac Arrest

1. Start CPR Immediately

The first and most critical step is to begin high-quality CPR as soon as cardiac arrest is recognized. Deliver chest compressions at a rate of 100–120 per minute with a depth of at least 2 inches (5 cm). Ensure full chest recoil between compressions and minimize interruptions to maintain blood flow to vital organs.

2. Check the Rhythm

After starting CPR, quickly assess the patient’s heart rhythm to determine if it’s shockable, such as ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT). Identifying whether the rhythm is shockable or non-shockable (like asystole or pulseless electrical activity) is crucial, as it guides your next life-saving actions.

3. If Shockable (VF/pVT): Deliver 1 Shock

If the victim’s cardiac rhythm is identified as shockable, such as ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT).

Deliver an electric shock using a defibrillator as soon as a shockable rhythm is identified. This shock helps reset the heart’s electrical activity and can restore a normal heartbeat.
Resume high-quality CPR immediately after the shock.
Continue for 2 full minutes without stopping to check the rhythm or pulse.
Maintain proper chest compressions at a rate of 100-120 per minute and a depth of 2-2.4 inches and ventilations to support circulation.

4. If Non-Shockable (Asystole/PEA): Resume CPR

If the cardiac rhythm is identified as non-shockable, such as asystole or pulseless electrical activity (PEA), do not deliver a shock.

Immediately resume high-quality CPR for 2 minutes without interruption to maintain blood flow to the brain and vital organs.
Establish IV or IO access during this cycle.
Administer epinephrine 1 mg as soon as possible, and repeat every 3–5 minutes throughout the resuscitation effort.
Continue rhythm checks every 2 minutes, and actively search for and treat reversible causes (H’s and T’s) to guide ongoing care.

Drug Therapy in ACLS Cardiac Arrest

Drug therapy plays a critical role in improving outcomes during cardiac arrest. Medications are used alongside high-quality CPR and defibrillation to support the heart’s function and increase the chances of return of spontaneous circulation (ROSC).

Epinephrine is the first-line drug in cardiac arrest and should be administered 1 mg IV/IO every 3–5 minutes during resuscitation. It helps improve blood flow to the heart and brain.
Amiodarone or Lidocaine may be given for shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) after the second or third shock.
Establishing IV or IO access early is essential to ensure the timely delivery of medications.
Drug therapy should be continued according to the patient’s rhythm and response, always accompanied by high-quality CPR and frequent rhythm checks.

Advanced Airway Management

Advanced airway management is a critical part of ACLS when basic airway methods are not sufficient to maintain oxygenation and ventilation.

Consider placing an advanced airway, such as an endotracheal tube (ETT) or supraglottic airway, if the patient is not breathing adequately.
Once an advanced airway is in place, switch to continuous chest compressions without pausing for breaths.
Provide 1 breath every 6 seconds (10 breaths per minute) while maintaining effective compressions.
Confirm correct tube placement using waveform capnography (ETCO₂ monitoring) or other reliable methods.
Monitor for signs of return of spontaneous circulation (ROSC) or any changes in the patient’s condition that may require adjustments in airway support.

Identify & Treat Reversible Causes (the “H’s & T’s”)

Reversible causes of cardiac arrest, known as the H’s and T’s, must be quickly identified and treated to improve the chance of successful resuscitation. These are common underlying conditions that can lead to or worsen cardiac arrest.

The H’s:

Hypovolemia – Severe blood or fluid loss
Hypoxia – Inadequate oxygen supply
Hydrogen ion (Acidosis) – Excess acid in the body
Hypo-/Hyperkalemia – Abnormally low or high potassium levels
Hypothermia – Critically low body temperature

The T’s:

Tension pneumothorax – Collapsed lung with pressure on the heart
Cardiac tamponade – Fluid buildup around the heart
Toxins – Drug overdose or poisoning
Pulmonary thrombosis – Blood clot in the lungs (PE)
Coronary thrombosis – Blocked coronary artery (heart attack)

Return of Spontaneous Circulation (ROSC)

Return of Spontaneous Circulation (ROSC) means the heart has started beating on its own again by restoring blood flow. Signs of ROSC include a pulse, normal breathing, or a rise in end-tidal CO₂. Once ROSC is achieved, begin post-cardiac arrest care immediately and focus on supporting breathing, maintaining blood pressure, identifying the cause of the adult cardiac arrest, and preventing complications. Interventions may include oxygen support, ECG monitoring, IV fluids or medications, and targeted temperature management to protect brain function.

Essential Takeaways from ACLS Cardiac Arrest Protocol

When rescuing a cardiac arrest victim, it is essential to follow the correct steps at the right time. High-quality CPR and timely defibrillation are critical interventions that significantly improve the chances of survival. Early rhythm analysis, appropriate medication administration, and identifying reversible causes play a key role in successful resuscitation protocol and achieving return of spontaneous circulation (ROSC). If you want to learn life-saving skills and understand the AHA ACLS algorithm in depth, visit the CPRVAM CPR Training Center at a location near you.

FAQs

1. What is the AHA ACLS Cardiac Arrest Algorithm?

The AHA ACLS Cardiac Arrest Algorithm is a structured, step-by-step guide used by healthcare providers to manage cardiac arrest. It combines high-quality CPR, timely defibrillation, medication administration, advanced airway support, and identification of reversible causes to improve the chances of survival and recovery.

2. What are the steps in the ACLS cardiac arrest algorithm?

The ACLS cardiac arrest algorithm includes these key steps: start high-quality CPR immediately, check the rhythm to see if it’s shockable, deliver a shock if needed, resume CPR for 2 minutes, give epinephrine every 3–5 minutes, consider advanced airway placement, administer antiarrhythmic drugs if indicated, and identify and treat reversible causes (the H’s and T’s). Continue cycles of CPR and rhythm checks until return of spontaneous circulation (ROSC) or termination of efforts.

3. How do I know if a rhythm is shockable or non-shockable?

Shockable rhythms include ventricular fibrillation and pulseless ventricular tachycardia. Non-shockable rhythms are asystole and pulseless electrical activity. The treatment depends on this classification.

4. When should epinephrine be given in ACLS?

Epinephrine should be administered as soon as IV or IO access is established and then repeated every 3–5 minutes during cardiac arrest to help stimulate the heart and improve blood flow to vital organs.

5. What happens after Return of Spontaneous Circulation (ROSC)?

After ROSC, care focuses on stabilizing the patient by ensuring a clear airway, supporting breathing and blood pressure, monitoring vital signs, and preventing brain injury through treatments like targeted temperature management.