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Activating EMS and Effective Cardiopulmonary Resuscitation

This year, there will be 350,000 people in the US and Canada who will suffer from cardiac arrest and receive attempted resuscitation.1-5 In-hospital cardiac arrest is estimated to be 3 to 6 per 1,000 admissions.2-4 Modest improvement in survival is all it takes to save thousands of lives every year. The American Heart Association (AHA) 2010 guidelines displayed a breakthrough in Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC).

The adult chain of survival represents well-coordinated steps and procedures to address cardiac arrest. The goals of successful resuscitation include:

  1. Immediate recognition of cardiac arrest and activation of the emergency response system.
  2. Early CPR with an emphasis on chest compressions.
  3. Rapid defibrillation.
  4. Effective advanced life support.
  5. Integrated post–cardiac arrest care.
  6. This article will explain clearly and concisely the first two links in the adult chain of survival.

First link: Immediate recognition of cardiac arrest and activation of the emergency response system

Immediate recognition of patients in need of cardiopulmonary resuscitation is a key component before activating the emergency response system and progressing through the adult chain of survival. The healthcare provider should be able to immediately recognize unresponsive patients who are in cardiac arrest. Healthcare providers should identify patients who are without apneic or not breathing normally.  No normal breathing is defined as cardiac arrest patients with “agonal gasps”.12 These are short gasping, ineffective breaths following cardiac arrest and may confuse rescuers. . One major change from the 2005 guidelines is that the “Look, listen and feel” step for breathing is no longer part of the algorithm.

Once the healthcare provider identifies that the patient is unresponsive, the emergency response system should be activated. It is important to attend to the patient right away. If there is someone around to assist then the healthcare provider should instruct him/her to retrieve the automatic external defibrillator (AED) or crash cart. Next, the rescuer should check for pulse within 10 seconds. If no pulse is felt, then the healthcare provider should begin CPR and prepare the defibrillator once available. 

Second link: Early CPR with an emphasis on chest compressions.

The new AHA guidelines reiterate the importance of effective chest compressions.  It is imperative that all healthcare providers provide high quality chest compressions (push hard and fast) on the center of the chest to all patients in cardiac arrest, keeping in mind the following:

  1. A rate of 100 to 120 chest compressions per minute.
  2. Adequate depth of 2 inches or 5 centimeters.
  3. Complete chest recoil after each compression.
  4. Uninterrupted chest compressions.
  5. Avoiding excessive ventilation.

This emphasis on immediate and effective chest compressions has radically changed the algorithm from A-B-C (airway, breathing, and chest compressions) to C-A-B (chest compressions, airway, and breathing). The majority of adult patients in cardiac arrest are determined to be in ventricular fibrillation or pulseless ventricular tachycardia; these patients have a better chance of survival compared to those who are in asystole or pulseless electrical activity.1,6-7 There is a 50% increase in survival for witnessed ventricular fibrillation cardiac arrest when immediate chest compressions and early defibrillation are employed.8-11 By changing the sequence to C-A-B, chest compressions are delivered faster with minimal delay in ventilations.

It is recommended to give 2 rescue breaths after 30 chest compressions for single health care providers; however, when multiple rescuers are present one breath every 6 to 8 seconds (8 to 10 breaths per minute) is adequate.  When giving rescue breaths opening the airway via head-tilt chin-lift or jaw thrust will provide optimal oxygenation. Ventilations are important when the cause of arrest is of an asphyxial nature. If a lone rescuer is not able to perform rescue breaths (i.e. untrained rescuer or trained rescuer but not proficient), then chest compressions without ventilation are acceptable.

Health care providers should use their judgment and tailor their rescue to different scenarios. For example, a rescuer should provide chest compressions and rescue breathing if the patient is a victim of asphyxial arrest (i.e. drowning). In this case, a delay in acquiring the AED is acceptable. In contrast, an AED should be sought immediately when an arrest is witnessed. In this scenario, it is assumed that the victim has had a primary cardiac arrest with a shockable rhythm.

In the 2010 AHA guidelines, there is an increased focus on teamwork and teams of rescuers. It is possible to simultaneously manage the individual components of the adult chain of survival to increase resuscitation proficiency. For example, one member of the team activates the emergency response system, another obtains the AED, another starts chest compressions and another provides ventilations. Therefore, training is focused on building a team as each rescuer arrives and designating a team leader once multiple rescuers are present.


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  13. 2016 American Heart Association Basic Life Support Provider Manual