April 6, 2002 started out like any other busy day during the National Cherry Blossom Festival, with crowds of tourists pouring into Washington, D.C., to view the blooming cherry trees and tour the Washington Monument, Lincoln’s Tomb and the Vietnam Veterans’ Memorial.
Officer Mark Varanelli was prepared for any emergency that might arise. As an experienced emergency services worker, he was trained in cardiopulmonary resuscitation (CPR) and in the use of automated external defibrillators (AEDs), portable devices that deliver a potentially life-saving electric shock to the hearts of victims suffering from sudden cardiac arrest. When he reported for work that morning, he had no idea he would use an AED later in the day to try to save a life.
While patrolling, Varanelli received a call that a tow truck operator was having trouble breathing. Within 2 minutes, Varanelli was at the Washington Monument, deploying an AED on the driver, Walter Kilpatrick. Because Varanelli was educated on the four steps in the cardiac chain of survival, Kilpatrick survived the incident and later was able to testify before Congress on the importance of public deployment of AEDs.
The four steps in the cardiac chain of survival are: 1) early recognition and early activation of 9-1-1 or the local emergency number; 2) initiating CPR; 3) early defibrillation using an AED; and 4) early advanced life support.
“Chances of survival from sudden cardiac arrest decreases 10 percent each minute after collapse,” said Mary Newman, executive director for the National Center for Early Defibrillation. “The key to survival is quick action on the part of those near the victim, so it is critical that people be prepared.”
In the time it takes you to read this article, sudden cardiac arrest will have claimed another victim. Statistics show that more than 300,000 Americans die of sudden cardiac arrest every year. As many as 50,000 of these deaths could have been prevented if someone had initiated the cardiac chain of survival.
Brain death starts to occur 4 to 6 minutes after someone experiences cardiac arrest if no CPR and defibrillation occurs during that time. If bystander CPR is not provided, a sudden cardiac arrest victim’s chances of survival fall 7 percent to 10 percent for every minute of delay until defibrillation. Few attempts at resuscitation are successful if CPR and defibrillation are not provided within minutes of collapse. About 900 Americans die every day due to sudden cardiac arrest.
Sudden cardiac arrest most often is caused by an abnormal heart rhythm called ventricular fibrillation (VF). Cardiac arrest also can occur after the onset of a heart attack or as a result of electrocution or near-drowning. When sudden cardiac arrest occurs, the victim collapses, becomes unresponsive to gentle shaking, stops normal breathing and after two rescue breaths, still isn’t breathing normally, coughing or moving.
Once witnesses have determined that a person is suffering from sudden cardiac arrest (SCA) and have called 9-1-1, the next step in the cardiac chain of survival is to begin CPR.
According to the American Heart Association (AHA), most victims of SCA demonstrate ventricular fibrillation (VF) at some point in their arrest. Resuscitation is most successful if defibrillation is performed in about the first 5 minutes after collapse. Because the interval between call to EMS and arrival of EMS personnel at the victim’s side is typically longer than 5 minutes, achieving high survival rates depends on a public trained in CPR and on well-organized public access defibrillation programs.
The AHA says the best results of lay rescuer CPR and AED programs have occurred in controlled environments, with trained, motivated personnel; a planned and practiced response; and short response times. Examples of such environments are airports, airlines, casinos and hospitals. Significant improvement in survival from out-of-hospital VF SCA also has been reported in well-organized police CPR and AED rescuer programs.
CPR is important both before and after shock delivery, according to AHA. When performed immediately after collapse from VF SCA, CPR can double or triple the victim’s chance of survival. CPR should be provided until an AED or manual defibrillator is available.
After about 5 minutes of VF with no treatment, the outcome may be better if shock delivery (attempted defibrillation) is preceded by a period of CPR with effective chest compressions that deliver some blood to the coronary arteries and brain. CPR also is important immediately after shock delivery, because most victims demonstrate asystole or pulseless electrical activity (PEA) for several minutes after defibrillation. CPR can convert these rhythms to a perfusing rhythm.
Not all adult deaths are due to SCA and VF. An unknown number have an asphyxial mechanism, such as in cases of drowning or drug overdose. Asphyxia is also the mechanism of cardiac arrest in most children, although about 5 percent to 15 percent have VF. Studies in animals have shown that the best results for resuscitation from asphyxial arrest are obtained by a combination of chest compressions and ventilations, although chest compressions alone are better than doing nothing.
The authors of the 2005 AHA Guidelines for CPR and ECC simplified the BLS sequences, particularly for lay rescuers, to minimize differences in the steps and techniques of CPR used for infant, child and adult victims. For the first time, a universal compression-ventilation ratio (30:2) is recommended for all single rescuers of infant, child and adult victims (excluding newborns).
Some skills (e.g., rescue breathing without chest compressions) will no longer be taught to lay rescuers. The goal of these changes is to make CPR easier for all rescuers to learn, remember and perform.
There are differences in CPR for lay rescuers and EMS or healthcare providers. As provided by AHA, these differences include:
- Lay rescuers immediately should begin cycles of chest compressions and ventilations after delivering two rescue breaths for an unresponsive victim. Lay rescuers are not taught to assess for pulse or signs of circulation for an unresponsive victim.
- Lay rescuers will not be taught to provide rescue breathing without chest compressions.
- The lone healthcare or EMS provider should alter the sequence of rescue response based on the most likely etiology of the victim’s problem.
For sudden collapse in victims of all ages, the lone healthcare provider or EMS responder should telephone the emergency response number and get an AED (when readily available) and then return to the victim to begin CPR and use the AED.
- For unresponsive victims of all ages with likely asphyxial arrest (eg, drowning) the lone healthcare provider or EMS responder should deliver about five cycles (about 2 minutes) of CPR before leaving the victim to telephone the emergency response number and get the AED. The rescuer should then return to the victim, begin the steps of CPR and use the AED.
- After delivery of 2 rescue breaths, healthcare and EMS providers should attempt to feel a pulse in the unresponsive, nonbreathing victim for no more than 10 seconds. If the rescuer does not definitely feel a pulse within 10 seconds, he or she should begin cycles of chest compressions and ventilations.
- Healthcare and EMS providers will be taught to deliver rescue breaths without chest compressions for the victim with respiratory arrest and a perfusing rhythm (i.e., pulses). Rescue breaths without chest compressions should be delivered at a rate of about 10 to 12 breaths per minute for the adult and a rate of about 12 to 20 breaths per minute for the infant and child.
- Healthcare and EMS providers should deliver cycles of compressions and ventilations during CPR when there is no advanced airway (e.g., endotracheal tube, laryngeal mask airway or esophageal-tracheal combitube) in place. Once an advanced airway is in place for infant, child or adult victims, two rescuers no longer deliver “cycles” of compressions interrupted with pauses for ventilation. Instead, the compressing rescuer should deliver 100 compressions per minute continuously, without pauses for ventilation. The rescuer delivering the ventilations should give eight to 10 breaths per minute and should be careful to avoid delivering an excessive number of ventilations. The two rescuers should change compressor and ventilator roles approximately every 2 minutes to prevent compressor fatigue and deterioration in quality and rate of chest compressions. When multiple rescuers are present, they should rotate the compressor role about every 2 minutes. The switch should be accomplished as quickly as possible (ideally in less than 5 seconds) to minimize interruptions in chest compressions.
AEDs are computerized medical devices that can check a person’s heart rhythm and recognize a rhythm that requires a shock. It can advise the rescuer when a shock is needed by utilizing voice prompts, lights and text messages to tell the rescuer the steps to take.
AEDs are very accurate and easy to use. Learning to operate an AED safely takes only a couple of hours of training. There are many different brands of AEDs, but the same basic steps apply to all of them.
Training is key because an AED operator must know how to recognize the signs of a sudden cardiac arrest, when to activate the EMS system and how to do CPR. It also is important for operators to receive formal training on the AED model they will use, so that they become familiar with the device and are able to successfully operate it in an emergency. Training also teaches the operator how to avoid potentially hazardous situations.
Ideally, the American Red Cross would like to have one person in every household trained in first aid and CPR lifesaving skills, and have all Americans be within 4 minutes of an AED and someone trained to use it in the event of sudden cardiac arrest. AHA strongly advocates that all EMS first-response vehicles and ambulances be equipped with an AED or another defibrillation device (semiautomatic or manual defibrillator). AHA also supports placing AEDs in targeted public areas such as sports arenas, gated communities, office complexes, doctor’s offices, shopping malls and schools, among other locations.
When AEDs are placed in the community or a business or facility, AHA strongly encourages that the instruments be part of a defibrillation program in which:
- Persons that acquire an AED notify the local EMS office. It’s important for the local EMS system to know where AEDs are located in the community. In the event of a sudden cardiac arrest emergency, the 9-1-1 dispatcher will know if an AED is on the premises and will be able to notify the EMS system as well as the responders already on the scene.
- A licensed physician or medical authority provides medical oversight to ensure quality control. The licensed physician or medical authority will ensure that all designated responders are properly trained and that the AED is properly maintained. He or she also can help establishments develop an emergency response plan for the AED program.
- Persons responsible for using the AED are trained in CPR and how to use an AED. Early CPR is an integral part of providing lifesaving aid to people suffering sudden cardiac arrest. CPR helps to circulate oxygen-rich blood to the brain. After the AED is attached and delivers a shock, the typical AED will prompt the operator to continue CPR while the device continues to analyze the victim.
The police often are the first responders on the scene when 9-1-1 is called. Some police departments are reluctant to have their officers carry and use AEDs for fear of potential litigation. Agencies such as AHA and the American Red Cross point out that if the person is a trained and licensed medical first responder, an established standard of care is outlined in the law, and those operating within these guidelines are protected under these laws.
These same guidelines pertain to the personnel in the EMS system. If they are not trained and licensed medical first responders, check your state laws to determine if lay rescuers are given limited liability immunity. If not, they may not be protected from litigation. Agencies should seek legal counsel before implementing a defibrillation program.