Cardiopulmonary resuscitation (CPR) is an emergency first aid procedure for a victim of cardiac arrest. It is part of the chain of survival, which includes early access (to emergency medical services), early CPR, early defibrillation, and early advanced care. It is also performed as part of the choking protocol if all else has failed. It can be performed by trained laypersons or by health care or emergency response professionals. It is normally begun on an unbreathing unconscious person and continued until the underlying cause can be identified and a pulse is restored. CPR consists of chest compressions and rescue breaths (i.e. artificial blood circulation and lung ventilation) and is intended to maintain a flow of oxygenated blood to the brain and the heart, thereby extending the brief window of opportunity for a successful resuscitation without permanent brain damage.
Many countries have official guidelines on how CPR should be provided, and these naturally override the general description of CPR in this article.
In 2005, new CPR guidelines were published with input from International Resuscitation Councils, and was agreed at the 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science. The primary goal was to simplify CPR for lay rescuers and healthcare providers alike to maximise the potential for early resuscitation. The important changes for 2005 are as follow.
As research has shown that lay personnel cannot accurately detect a pulse in about 40% of cases and cannot accurately discern the absence of pulse in about 10%, the pulse check step has been removed from the CPR procedure completely for lay persons and de-emphasized for healthcare professionals.
The medical term for the condition in which a person's heart has stopped is cardiac arrest (also referred to as cardiorespiratory arrest). CPR appropriate for cardiac arrest. If the patient still has a pulse, but is not breathing, this is called respiratory arrest and rescue breathing is more appropriate.
However, since people often can't tell the difference (can't accurately feel a pulse to determine whether the heart is still beating), CPR is often recommended for both.
The most common cause of cardiac arrest outside of a hospital is ventricular fibrillation (VF), a potentially fatal arrhythmia that is usually (but not always) caused by a heart attack. Other causes of cardiac arrest include drowning, drug overdose, poisoning, electrocution.
Sudden cardiac arrest is a leading cause of death, approximately 250,000 per annum outside a hospital setting in the USA. CPR can double or triple the victim's chances of survival when commenced immediately. According to American Heart Association, only two thirds of victims of a witnessed cardiac arrest are administered CPR. Rapid access to defibrillation is also vital.
Blood circulation and lung ventilation are absolute requirements in transporting oxygen to the tissues. The brain may sustain damage after four minutes and irreversible damage after about seven minutes The heart also rapidly loses the ability to maintain a normal rhythm. Low body temperatures as seen in drownings prolong the time the brain survives. Following cardiac arrest, effective CPR enables enough oxygen to reach the brain to delay brain death, and allows the heart to remain responsive to defibrillation attempts.
CPR is taught to the general public because they are the only ones present in the crucial few minutes before emergency personnel are available. Simple training is the goal of the 2005 guidelines to maximise the prospect that CPR will be performed successfully.
CPR is almost never effective if started more than 15 minutes after collapse because permanent brain damage has probably already occurred, especially if the person has stopped breathing, since the brain can only survive for 4-6 minutes without oxygen. A notable exception is cardiac arrest occurring in conjunction with exposure to very cold temperatures. Hypothermia seems to protect the victim by slowing down metabolic and physiologic processes, greatly decreasing the tissues' need for oxygen. There are cases where CPR, defibrillation, and advanced warming techniques have revived victims after substantial periods of hypothermia.
Used alone, few patients will make a complete recovery, and those that do survive often develop serious complications. Estimates vary, but many organizations stress that CPR does not "bring anyone back," it simply preserves the body for defibrillation and advanced life support. However, in the case of "non-shockable" rhythms such as Pulseless Electrical Activity (PEA), defibrillation is not indicated, and the importance of CPR rises. On average, only 5%-10% of people who receive CPR survive. The purpose of CPR is not to "start" the heart, but rather to circulate oxygenated blood, and keep the brain alive until advanced care (especially defibrillation) can be initiated. As many of these patients may have a pulse that is unpalpable by the layperson rescuer, the current consensus is to perform CPR on a patient that is not breathing. A pulse check is not required in basic CPR since it is so often missed when present, or even felt when absent, even by health care professionals
Studies have shown the importance of immediate CPR followed by defibrillation within 3–5 minutes of sudden VF cardiac arrest improve survival. In cities such as Seattle where CPR training is widespread and defibrillation by EMS personnel follows quickly, the survival rate is about 30 percent. In cities such as New York City, without those advantages, the survival rate is only 1-2 percent.
CPR is often severely misportrayed in movies and television as being highly effective in resuscitating a person who is not breathing and has no circulation. A 1996 study published in the New England Journal of Medicine showed that CPR success rates in television shows was 75%.
It is considered by a number of international bodies that in order for CPR to be effective, the guidelines must be simple and easy to remember.
CPR is a practical skill and needs professional instruction followed up by regular practice on a resuscitation mannequin to gain and maintain full competency. Training is available through many commercial, volunteer and government organizations worldwide.
CPR training is not confined to the medical professionals. To be effective, CPR must be applied almost immediately after a patient's heart has stopped. Early CPR on the scene of an incident is essential to the prevention of brain damage during a cardiac arrest. Blood flow and air supply to the brain and other major organs is maintained until a defibrillator and professional medical help arrives. Almost anyone is able to perform CPR with training, and health organizations advocate the development of CPR skills throughout the general public.
It is best to obtain training in CPR before a medical emergency occurs. One needs hands-on training by experts to perform CPR safely, and guidelines change, so that training should be repeated every one or two years. Training in first aid is often available through community organizations such as the Red Cross and St. John Ambulance. In many countries in the Commonwealth of Nations, St. John Ambulance and the Medic First Aid Organization provide CPR training. In Scotland, St. Andrew's Ambulance Association provides first aid training. In the United States, the American Red Cross, American Heart Association and American CPR Training also offer CPR training. In addition, many employees at public areas or community centres are trained in CPR. Lifeguards are also trained in CPR and other first aid protocols.
In most CPR Classes a simple shortform is used for people to remember everything they need to do. The most common one used worldwide is DRABCD which stands for Danger, Response, Airway, Breathing, Compressions and Defibrillation.
CPR has been known in theory, if not practice, for many hundreds or even thousands of years; some claim it is described in the Bible, discerning a superficial similarity to CPR in a passage from the Books of Kings (II 4:34), wherein the Hebrew prophet Elisha warms a dead boy's body and "places his mouth over his". In the 19th century, doctor H. R. Silvester described a method (The Silvester Method) of artificial respiration in which the patient is laid on their back, and their arms are raised above their head to aid inhalation and then pressed against their chest to aid exhalation. The procedure is repeated sixteen times per minute. This type of artificial respiration is occasionally seen in movies made in the early part of the 20th century.
A second technique, described in the first edition of the Boy Scout Handbook in the United States in 1911, described a form of artificial respiration where the person was laid on their front, with their head to the side, and a process of lifting their arms and pressing on their back was utilized, essentially the Silvester Method with the patient flipped over. This form is seen well into the 1950s (it is used in an episode of Lassie during the Jeff Miller era), and was often used, sometimes for comedic effect, in theatrical cartoons of the time. This method would continue to be shown, for historical purposes, side-by-side with modern CPR in the Boy Scout Handbook until its ninth edition in 1979.
However it wasn't until the middle of the 20th century that the wider medical community started to recognise and promote it as a key part of resuscitation following cardiac arrest. Peter Safar wrote the book ABC of resuscitation in 1957. In the U.S., it was first promoted as a technique for the public to learn in the 1970s. Early marketing efforts oversold the effectiveness of CPR in rescuing heart attack and other victims, and this misperception continues even today, as the success rate for CPR is only 1/20.
A form of "self-CPR" termed "Cough CPR" may help a person maintain blood flow to the brain during a heart attack while waiting for medical help to arrive and has been used in a hospital emergency room in cases where "standard CPR" was contraindicated. While this technique is not in widespread use, one researcher has recommended that it be taught broadly to the public However, the American Heart Association (AHA), does not endorse "Cough CPR", which it terms a misnomer as it is not a recognized form of resuscitation. The AHA does recognize a limited legitimate use of the coughing technique:
This coughing technique to maintain blood flow during brief arrhythmias has been useful in the hospital, particularly during cardiac catheterization. In such cases the patient's ECG is monitored continuously, and a physician is present.
"Cough CPR" was the subject of a hoax chain e-mail entitled "How to Survive a Heart Attack When Alone" which wrongly cited "ViaHealth Rochester General Hospital" as the source of the technique. Rochester General Hospital has denied any connection with the technique.
1. To check an unconscious victim, place two fingers under his chin and a hand on his forehead. Tilt his head back to open his airway. Remove any obstructions from his mouth.
3. Check the victim's circulation by feeling for a pulse at the side of his windpipe (carotid artery). If there is no pulse, begin CPR immediately.
1. If a victim is unconscious but breathing, bend his near arm up at a right angle to his body. Hold the back of his far hand to his near cheek. With the near leg straight, pull the far knee toward you.
2. With the victim on his side, place his uppermost leg at a right angles to his body. His head will be supported by the hand of the uppermost arm. Tilt his head back so that he will not choke if he vomits.
1. To ensure an open airway, first clear the victim's mouth of obstructions, then place one hand under his chin and one on his forehead, and tilt his head back.
2. Pinching the victim's nose shut, clamp your mouth over his mouth, and blow steadily for about two seconds until his chest rises. Remove your mouth and let his chest fall, then repeat.
3. Listen for the victim's breathing and check his pulse. If he still has a pulse, give 10 breaths per minute until help arrives or the victim is breathing by himself. If the pulse has stopped, combine rescue breathing with chest compressions.
If a person's heart has stopped, give cardiopulmonary resuscitation (CPR). This consists of chest compressions to maintain the blood flow to the brain, combined with rescue breathing to oxygenate the blood. Give chest compressions at a rate of 80 per minute, counting "one-and-two-and..."
1. Place the heel of your hand two finger-widths up from the end of the sternum and your other hand on top of the first. Press down firmly, then release.
2. Check for a pulse. After 15 chest compressions, give the victim two breaths of rescue breathing. Repeat until the pulse restarts, professional help arrives, or you are too exhausted to continue.
Control of the airway is the single most important task for emergency resuscitation. If the patient has inadequate oxygenation or ventilation, inability to protect the airway due to altered sensorium from illness or drugs, or external forces compromising the airway (i.e., trauma), he or she may need advanced airway techniques as described in this chapter.