Cardiac Arrest Circular Algorithm Explained

Introduction to the Cardiac Arrest Circular Algorithm

During cardiac emergencies, the Cardiac Arrest Circular Algorithm provides essential life-saving steps.

The Cardiac Arrest Circular Algorithm guides providers on the correct procedures to provide high-quality cardiopulmonary resuscitation. It begins after recognizing that a patient is in cardiac arrest (no pulse and no normal breathing).

The first step is to provide chest compressions with ventilations. In the hospital setting or during a paramedic rescue, essential equipment will be available for use. That involves oxygen delivery equipment and positive-pressure ventilation devices, such as an oxygen tank and a bag-mask device. 

Another essential device is a manual defibrillator. The manual defibrillator is applied to the patient as soon as possible, being careful to minimize interruptions in chest compressions as it is being attached to the patient. 

Once the defibrillator is connected, the provider should perform a rhythm check immediately. If a shockable rhythm is present, the device is charged. While charging, chest compressions and ventilations resume. As soon as the device is charged, the patient is cleared and the shock is administered. Afterward, the provider immediately performs five cycles or two minutes of high-quality CPR.¹

Healthcare providers must utilize the essential equipment immediately during CPR, keeping in mind the key actions: (1) early diagnosis of cardiac arrest, (2) immediately performing CPR, and (3) immediate defibrillation.

Read: Acute Coronary Syndrome – The ACS Algorithm

Push Hard and Fast in the Center of the Chest

To initiate CPR, the provider utilizes chest compressions. Using the two-handed technique rescuers should remember to push hard and push fast in the center of the chest. Chest compressions are applied to the lower half of the sternum. Depressions should be at least 2–2.4 inches, allowing for full chest recoil on the upstroke at a rate of 100–120 per minute.

Chest compression technique is important. Push hard and allow the chest to recoil after each push.

Related Video – CPR for Adults with 2 Rescuers

Positive-Pressure Ventilation

When using a bag-mask device or other barrier device to provide positive-pressure ventilation, the rescuer should provide two breaths after sets of 30 chest compressions with 100% supplemental oxygen. This cycle is performed for 2 minutes. During this time, high-quality CPR should be maintained.²

Adjustments are made as needed. The provider should make sure compression depth, full chest recoil, and compression rate are being followed. When providing ventilations, the provider should ensure there is a visible chest rise as each breath is being provided. That is an indication that the ventilations are adequate.

Related Video – Understanding Bag Valve Mask Usage During CPR

Pulse Check and Rhythm Check

After two minutes, the provider should perform a pulse and rhythm check. If there is no pulse but a shockable rhythm is present, clear the patient is cleared and a shock is delivered. At this point, the rescuers must switch places to prevent rescuer fatigue. Studies show that once a rescuer feels arm strain and fatigue, the quality of chest compression decreases. 

Chest compressions and ventilations are resumed immediately after giving the shock.

Intravenous Medications: Epinephrine

The circular algorithm is repeated. The provider should consider gaining intravenous (IV) or intraosseous access for epinephrine. Once access is established, 1 mg of epinephrine is administered intravenously at a dilution of 1:10,000 followed by a bolus 10-mL normal saline flush every 3–5 minutes. 

It is recommended to elevate the extremity where the IV access is in place while administering drugs in cardiac arrest patients. Also, drugs should be administered with chest compressions. These actions facilitate the flow of the drugs to the central circulation.

Intravenous Medications: Amiodarone

If the patient remains in a shockable rhythm after three shocks, amiodarone is initially administered at 300 mg intravenously followed by a 10-mL normal saline flush. Again, the extremity should be elevated and chest compressions continued when giving these drugs to facilitate transport to the central circulation. Subsequent doses of amiodarone can be given but at a lower dose of 150 mg.

Airway Management

Providers should consider inserting an advanced airway, such as endotracheal intubation with quantitative waveform capnography. Once the endotracheal tube is inserted, asynchronous ventilations can be performed. That means that while performing uninterrupted chest compressions, the rescuer should give one breath every six seconds timed at the full chest recoil of the chest compression phase. 

Quantitative waveform capnography can be used to assess CPR quality. If the measured end-tidal pCO₂ concentration is below 10 mm Hg, then CPR techniques need improvement or there could be a problem with chest compressions and ventilation.

The favorable outcome in providing high-quality CPR is the return of spontaneous circulation (ROSC). ROSC is confirmed if a pulse and blood pressure are present. Quantitative waveform capnography will show an increase of pCO₂ concentration to more than 40 mm Hg.³

Reversible Causes of Cardiac Arrest

This article introduced the Cardiac Arrest Circular Algorithm. Recognition of cardiac arrest prompts care providers to begin the steps of the algorithm. High-quality CPR is the first and most important step in treating patients in cardiac arrest.