FAQs: Basic Life Support (CPR)

This page contains answers to your frequently asked questions on Basic Life Support (CPR).

Below, you'll find a series of topics relating to Basic Life Support. When you click the topic, you will see all of the questions and answers on this topic.

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These questions relate to adult basic life support. To view the answers, click the question or the + sign next to the question.

Yes, it is safe to defibrillate a victim who is lying on a metallic or wet surface. If the self-adhesive pads are applied correctly, and provided there is no direct contact between the user and the victim when the shock is delivered, there is no direct pathway that electricity could take that would cause the user to experience shock. 

If the victim is wet, their chest should be dried so that the self-adhesive AED pads will stick properly. As with any attempt at defibrillation, particular care should be taken to ensure that no one is touching the victim when a shock is delivered.

The initial shout for help has been removed as a separate step for simplicity and to reduce delay in starting CPR and getting an AED - a key evidence-based intervention linked to the Chain of Survival. 

A bystander may shout for help at any stage during the initial assessment and subsequent resuscitation attempt. 80% of out of hospital cardiac arrests occur in the home and the rescuer is likely to know if others are present and whether a shout for help is indicated. Observational data report that in most out-of-hospital cardiac arrests in the home, only a single bystander is present.

Whenever possible, the call to emergency services should be made from the patient’s side to allow a real-time assessment of the patient’s status by the dispatch operator and for them to provide CPR instruction if required.

There has been no change in who should deliver the full paediatric BLS sequence with Guidelines 2015. The full paediatric BLS sequence of 15:2 is still aimed at healthcare professionals with a duty to respond to paediatric emergencies (e.g. Emergency Department staff, paediatric doctors and nurses, paramedics). These people usually work in teams of two or more rescuers.

Members of the public should be taught the adult BLS sequence of 30 compressions : 2 ventilations.

Cardiorespiratory arrest occurs less frequently in children and many children do not receive resuscitation because potential rescuers fear causing harm. This fear is unfounded; it is far better to use the adult BLS sequence for resuscitation of a child than to do nothing. Guidelines 2015 reiterate this approach and promote the delivery of BLS by the general public and the use of the same sequence on children who are not responsive and not breathing normally. 

Members of the public with responsibility for the care of children (e.g. teachers, lifeguards) should be taught the adult BLS sequence of 30:2 with the following modification that makes it more suitable for use on children:

  • Give 5 initial breaths before starting chest compressions.
  • If on your own, perform CPR for approximately 1 minute before going for help.
  • Compress the chest by one-third of its depth, approximately 4 cm for an infant and approximately 5 cm for an older child. Use two fingers for an infant under one year; use one or two hands for a child over one year to achieve an adequate depth of compression.

There are other potential rescuers such as dentists, general practitioners, health visitors, and school nurses who are healthcare professionals working with children, but they often work alone. Although they may have to resuscitate a child, this would be a very unusual event and they are more likely to have to resuscitate a parent or grandparent. It would be sufficient to teach these groups the adult sequence of 30:2 with the paediatric modifiers unless they express a particular wish or interest to learn the full paediatric sequence.
 

These questions relate to cardiopulmonary resuscitation (CPR). To view the answers, click the question or the + sign next to the question.

The letters CPR stand for cardiopulmonary resuscitation. The term embraces all the procedures from basic first aid to the most advanced medical interventions that can be used to restore the breathing and circulation in someone whose heart and breathing have stopped.

For lay people and first aiders, CPR refers to the basic first aid procedures that can be used to keep someone alive until the emergency medical services can get to the scene. The most important skills are chest compressions to pump blood around the body, and rescue breaths to provide oxygen. Rescue breaths are also known as ‘mouth to mouth’.

Cardiac arrest means that the heart has stopped pumping blood around the body. This may occur for many reasons, but loss of the electrical coordination that controls the normal heartbeat is usually responsible.

The most likely cause is ventricular fibrillation, in which the normal orderly electrical signal that controls the heartbeat becomes completely disorganised and chaotic, and the heart is unable to act as a pump. Ventricular fibrillation can be treated with a defibrillator that delivers a high energy shock to restore the heart’s normal rhythm.

No, the terms mean different things. Although ‘heart attack’ is often used to refer to a sudden cardiac arrest, this is incorrect. A heart attack (or myocardial infarction, to use the medical term) occurs when an artery supplying the heart with blood becomes blocked. This usually causes chest pain and leads to damage to some of the muscle of the heart. It may cause cardiac arrest, particularly in the early stages, but this is not inevitable.

The risk of cardiac arrest, however, emphasises the importance of calling for immediate help if anyone is suspected of having a heart attack, so that they can receive treatment to reduce the damage to their heart and reduce the risk of a cardiac arrest occurring.

If bystanders who witness a cardiac arrest perform CPR, sufficient blood containing oxygen will reach the brain, heart and other organs to keep the person alive for several minutes. CPR by itself will not restart the heart, but it ‘buys time’ for the emergency medical services to reach the scene. Effective CPR more than doubles the chance of someone surviving a cardiac arrest.

Compression-only CPR describes the performance of uninterrupted chest compressions without rescue breathing. In many adults who suffer a cardiac arrest, the heart stops abruptly; breathing will have been normal (or nearly normal), so the blood should be well oxygenated. In this situation compression-only CPR may be effective for the first few minutes after the heart stops. This may provide time for the emergency services to arrive or an AED to be collected. Ultimately the oxygen will be used up and rescue breaths are required to give the victim the best chance of resuscitation.

Where cardiac arrest is caused by lack of oxygen (as in drowning and most arrests that occur in children) compression-only CPR will be much less effective.

Chest compression alternating with rescue breaths is the ideal first aid procedure, but for untrained bystanders or those unwilling to give rescue breaths, compression-only CPR (hands only) is a useful alternative.

When the heart stops, blood supply to the brain also stops. The victim will collapse unconscious and will be unresponsive. Breathing also stops, although it may take a few minutes to stop completely. For the first few minutes the victim may take noisy, infrequent or gasping breaths. The key features of cardiac arrest are therefore someone who is unconscious, unresponsive and NOT BREATHING NORMALLY. Noisy, infrequent or gasping breaths is not normal breathing.

If you have any doubt whether someone is breathing normally or not, assume it is NOT normal: call 999 immediately and start CPR. 

The Chain of Survival describes a sequence of steps that together maximise the chance of survival following cardiac arrest.

Chain of survival
Figure 1: Chain of Survival

 

  • The first link in the chain is the immediate recognition of cardiac arrest and calling for help.
  • The second is the prompt initiation of CPR.
  • The third is performing defibrillation as soon as possible.
  • The fourth is optimal post resuscitation care. 

Like any chain, it is only as strong as its weakest link. If one stage is weak, the chances of successful resuscitation are compromised.

When the heart is restarted after a cardiac arrest, recovery is not immediate. Admission to hospital is always required for further treatment and investigation to establish the cause. Provided good CPR has been performed while the heart has stopped and defibrillation has been carried out promptly, the outlook is very good with most patients making an excellent recovery.

In the UK fewer than 10% of all the people in whom a resuscitation attempt is made outside hospital survive. Improving this figure is a major priority for RCUK, the Department of Health and Social Care, ambulance services and first aid organisations.

When all the stages in the Chain of Survival take place promptly, the figures are very much better. This is possible where the arrest is recognised immediately, bystanders perform CPR, and an automated defibrillator is used before the ambulance service arrive. Survival rates in excess of 50% have been reported under these circumstances.

It is very unlikely that someone in the UK who acted in good faith when trying to help another person would be held legally liable for an adverse outcome. No such action has ever been brought against someone who performed CPR and, in general, the courts in the UK look favourably on those who go to the assistance of others.

Resuscitation Council UK has published detailed guidance on the legal status of those who attempt resuscitation. This provides answers to most of the commonly asked questions on the subject.

Training in CPR is provided by many organisations, and some classes also include instruction in the use of an AED. Many different kinds of training are provided, ranging from ‘hands-on’ classes with training manikins to purely internet-based distance-learning instruction. It is recommended that training should include practice on a training manikin.

Many ambulance services also teach the general public: contact your local service for further details.

The voluntary first aid organisations (for example St John Ambulance, St. Andrew’s Ambulance, The British Red Cross and the Royal Life Saving Society) provide instruction; contact the branch nearest to you for details. There are also many private first aid training companies that provide training, and an internet search will identify those in your area. 

The core principles of CPR - ventilation to provide breathing and chest compressions to support the circulation - apply equally to children and adults.

Many children do not receive CPR because potential rescuers are not sure if there are specific methods recommended for children, and are afraid of causing harm. This fear is unfounded; it is far better to use the adult CPR sequence for resuscitation of a child than to do nothing. When performing chest compressions, compress the child's chest by 1/3 to 1/2 of its depth - don't be afraid to push hard.

Although slightly different techniques are taught to those people (particularly healthcare workers) who have special responsibilities for the care of children, the differences are not crucial, and it is far more important to do something using the techniques you have been taught.

Fortunately, out-of-hospital cardiac arrest (OHCA) in childhood is a rare event. Studies of OHCA in children and adolescents (excluding infants under one year old) report an incidence between 3 and 9 per 100,000 per year. The rates reported in infants are generally much higher (between 11 and 72 per 100,000 infants per year). The cause in this latter group is often attributed to the Sudden Infant Death Syndrome (SIDS).

The incidence of cardiac arrest from a primarily cardiac cause (which includes cases referred to as “sudden cardiac arrest” or SCA) has been reported to be 2 – 3 per 100,000 per year in children and adolescents. SCA is more common in boys than girls, and more likely to occur during or just after sporting activity. 

Warning symptoms for future SCA may include previous episodes of collapse or near-collapse, dizziness, palpitations, chest pain, shortness of breath or unexplained episodes of brief seizure-like activity. Such symptoms may not always be present, however, and can be difficult to interpret in the setting of sporting activity, where those participating may often be pushing themselves to the point of exhaustion. A family history of cardiovascular disease and unexplained death at a young age may also be highly relevant.

Survival rates of 1.9 – 11.1% following attempted resuscitation have been reported, with good neurological outcome in many. Survival is more likely with witnessed events and a shockable rhythm on first ECG analysis - conditions often seen when an arrest occurs in a public location, like a school.

These questions relate to defibrillators. To view the answers, click the question or the + sign next to the question.

Resuscitation Council UK and British Heart Foundation have written a Guide to Automated External Defibrillators (AEDs) which gives full information about the use of AEDs in the community. We urge you to read this as it will answer your questions in more detail.

Sudden cardiac arrest (SCA) occurs because the normal electrical rhythm that controls the heart is replaced by a chaotic disorganised electrical rhythm called ventricular fibrillation (VF).

An AED delivers a high energy electric shock to a victim in SCA caused by VF to restore the heart’s normal rhythm. AEDs are compact, portable, easy to use and guide the operator through the process with prompts and commands. The AED analyses precisely the victim’s heart rhythm and will only deliver a shock if it is required. 

AEDs are very reliable and will not allow a shock to be given unless it is needed. They are extremely unlikely to do any harm to a person who has collapsed in suspected Sudden Cardiac Arrest. They are safe to use and present minimal risk to the rescuer. These features make them suitable for use by members of the public with little or no training).

Public Access Defibrillation describes the use of AEDs by members of the public. AEDs can now be found in many busy public places including airports, mainline railway stations, shopping centres, and gyms. They are meant to be used by members of the public if they witness a cardiac arrest.

RCUK has designed a sign which many public spaces equipped with a PAD will display. There are many different signs that mark the location of the AED. When you call the ambulance service you will be directed to the nearest registered device. Staff working at the location should also know the location of an AED nearby.

AEDs have been used by untrained people to save lives. Clear, spoken instructions and visual illustrations guide users through the process. Lack of training should not be a barrier to someone using one. If a person is in cardiac arrest, do not be afraid to use an AED.

Yes, it is usually safe to use an AED on a victim who is lying on a metallic, wet or other conductive surface. If the self-adhesive pads are applied correctly, and provided there's no direct contact between the user and the victim when the shock is delivered, there is no direct pathway that electricity can take that would cause the user to experience a shock. If the victim is wet, his/her chest should be dried so that the self-adhesive AED pads will stick properly.

Yes. The incidence of shockable rhythms requiring defibrillation in in children is very low but can occur. The priority must always be for high-quality CPR and getting expert help. However, the AED can be used across all age groups if this is the only available machine.

The paediatric advanced life support Guidelines 2015 state that if using an AED on a child of less than eight years, a paediatric attenuated shock energy should be used if possible. 

Experience with the use of AEDs (preferably with dose attenuator) in children younger than one year is limited. The use of an AED is acceptable if no other option is available as, on balance, it is probably better to give a 50 J shock than nothing at all. The upper safe limit for dosage in this group is unknown.

Yes. Fortunately cardiac arrest is rare in people who are pregnant, but if it were to occur it is quite appropriate to use an AED. The procedure is the same as in the non-pregnant but it is important to place the pads clear of enlarged breasts.

Fortunately, sudden cardiac arrest (SCA) in school-age children is rare. Resuscitation attempts at schools are more likely to be made on an adult (staff member or visitor) than a pupil. The presence of an AED at a school therefore provides potential benefit for everyone present at the site.

An additional and important advantage of having an AED prominently located at a school is that students become familiar with them and can learn about first aid, resuscitation and the purpose of defibrillation.

The Department of Education has issued guidance about the installation of AEDs in schools.

If you think an AED should be installed in your workplace, read the Guide to AEDs written by RCUK and the BHF as this will answer your questions in detail. If you wish to proceed, contact your local ambulance service for further advice as described in the Guide.

These questions relate to choking. To view the answers, click the question or the + sign next to the question.

Yes. Choking is an uncommon but potentially treatable cause of accidental death. As most choking events are associated with eating, they are commonly witnessed. As victims are initially conscious and responsive, early interventions can be life-saving. The 'Rebecca' scenario in Lifesaver shows what to do if someone is choking and demonstrates the value of early intervention in choking.

Both adults and children may be victims of choking. It is essential to recognise what is happening. The context may provide important clues. For example, choking is common at mealtimes, or a child may have been playing with small objects.

The victim may go silent and hold or point to their throat. If the obstruction to the airway is only partial, the victim may be able to speak, cough and breathe. Encourage them to cough and clear the obstruction but keep a close eye on them to make certain that the situation does not get worse.

If the airway is severely obstructed, the victim will not be able to talk, but may be able to respond by nodding or shaking their head. Coughing will be ineffective, breathing will be difficult, noisy or, at worst, impossible. Without treatment the victim will ultimately lose consciousness.

Severe airways obstruction is treated by measures that aim to increase the pressure inside the chest and thereby expel the obstruction.

Watch The Chokeables from St John Ambulance.

It may be difficult to carry out abdominal thrusts in a choking victim who is very obese, and abdominal thrusts should be not be performed on a pregnant person. If you are unable to encircle the victim's abdomen, you should stand behind the victim, as for abdominal thrusts, but position your hands somewhat higher, over the lower end of the sternum (breastbone). Pull hard into the chest with quick thrusts.

January 2014

These questions relate to paediatric basic life support. To view the answers, click the question or the + sign next to the question.

There has been no change in who should deliver the full paediatric BLS sequence with Guidelines 2015. The full paediatric BLS sequence of 15:2 is still aimed at healthcare professionals with a duty to respond to paediatric emergencies (e.g. Emergency Department staff, paediatric doctors and nurses, paramedics). These people usually work in teams of two or more rescuers.

Lay people should be taught the adult BLS sequence of 30 compressions : 2 ventilations.

Cardiorespiratory arrest occurs less frequently in children and many children do not receive resuscitation because potential rescuers fear causing harm. This fear is unfounded; it is far better to use the adult BLS sequence for resuscitation of a child than to do nothing. Guidelines 2015 reiterate this approach and promote the delivery of BLS by the general public and the use of the same sequence on children who are not responsive and not breathing normally. 

Members of the public with a responsibility for the care of children (e.g. teachers, lifeguards) should be taught the adult BLS sequence of 30:2 with the following modification that makes it more suitable for use on children:

  • Give 5 initial breaths before starting chest compression.
  • If on your own, perform CPR for approximately 1 minute before going for help.
  • Compress the chest by one-third of its depth, approximately 4 cm for an infant and approximately 5 cm for an older child. Use two fingers for an infant under one year; use one or two hands for a child over one year to achieve an adequate depth of compression.

There are other potential rescuers such as dentists, general practitioners, health visitors, and school nurses who are healthcare professionals working with children, but they often work alone. Although they may have to resuscitate a child, this would be a very unusual event and they are more likely to have to resuscitate a parent or grandparent. It would be sufficient to teach these groups the adult sequence of 30:2 with the paediatric modifiers unless they expressed a particular wish or interest to learn the full paediatric sequence.

October 2015

The full paediatric BLS sequence is for healthcare professionals with a duty to respond to paediatric emergencies (e.g. Emergency Department staff, paediatric doctors and nurses, paramedics). These people usually work in teams of two or more rescuers.

Members of the public with a responsibility for the care of children (e.g. teachers, lifeguards) should be taught the adult sequence with the paediatric modifiers (see note below). It is recognised, however, that there are other potential rescuers that fall between these two groups, where it is unclear which sequence is the more appropriate.  The decision as to what should be taught may be made locally (e.g. by the Resuscitation Committee) according to circumstances and available resources. In coming to a decision, it may be helpful to ask the following questions:

  1. Are the providers healthcare professionals?  
  2. Would they normally be expected to have to resuscitate an infant or child during the course of their work?
  3. Do they usually work in a team?

Generally, the full paediatric sequence and compression: ventilation ratio of 15:2 should be taught to those who give a positive answer to all three questions.

General practitioners, health visitors, and school nurses, for example, are healthcare professionals working with children, but they often work alone. Although they may have to resuscitate a child, this would be a very unusual event and they are more likely to have to resuscitate a parent or grandparent. It would be sufficient to teach these groups the adult sequence of 30:2 with the paediatric modifiers unless they expressed a particular wish or interest to learn the full paediatric sequence.

Mental Health nurses working in child mental health units are healthcare professionals working in teams of two or more.  Although it would be unusual in most such units to have to resuscitate a child, some may treat high-risk children (such as those with severe anorexia nervosa) so it would be reasonable to allow training decisions to be based on local circumstances.

Note
Modifications to the adult BLS sequence of 30 compressions: 2 ventilations that will make it more suitable for use on children:

  • Give 5 initial breaths before starting chest compressions.
  • If on your own, perform CPR for approximately 1 minute before going for help.
  • Compress the chest by one-third of its depth, approximately 4 cm for an infant and approximately 5 cm for an older child. Use two fingers for an infant under one year; use one or two hands for a child over one year to achieve an adequate depth of compression.
October 2015

These questions relate to CPR and AED training. To view the answers, click the question or the + sign next to the question.

There are no statutory legal provisions in the UK relating to the practice of resuscitation or defibrillation, but both the users of AEDs and those who provide training in their use have obligations under common law. Further details may be found in our publication: CPR, AEDs and the law.

Resuscitation Council UK recommends that those who train others in CPR and the use of AEDs should be appropriately qualified, provided that they are skilled in teaching, and able to demonstrate competency in CPR and the use of an AED. 

Resuscitation Council UK does not currently provide CPR and AED training, nor does it accredit CPR/AED courses or CPR/AED Instructors.

Courses are offered by the voluntary aid societies and voluntary rescue organisations, some ambulance trusts, and private training organisations. Whilst there is no prescriptive course programme, these organisations should be teaching the Resuscitation Council UK recommendations.

There are a number of ways in which training can be delivered. Traditionally, Instructor led training has been used to facilitate acquisition of knowledge and skills. A number of other methods have been employed successfully which involve little or no Instructor involvement. A well designed and validated self-instructional programme using DVD or e-learning can be an effective alternative to Instructor-led training. It is essential that this method includes hands-on practice as part of the programme. Validation can be by the publication (and peer acceptance) of appropriate studies of the DVD programmes, or by the internal validation of such training programmes by the organisation that wishes to use it.

The length of CPR/AED courses across Europe varies and is dependent on the method of delivery; ratio of Instructors to participants; the amount of hands-on training; the equipment available; and, most importantly, the characteristics of the learners. For these reasons, it is not possible to recommend an optimum duration for a CPR/ AED course. The aim is to ensure all participants acquire the knowledge and skills required for them to act correctly in actual cardiac arrests, thereby improving patient outcomes.

It is important that resuscitation skills are refreshed regularly, particularly by those who have a duty to respond in an emergency. The principle is that skills should be maintained at an effective level at all times. Individual employers and organisations should make arrangements for retraining to be available, but the frequency of this refresher training will depend on the individual. For guidance, skills should be refreshed at least once a year, but preferably more often.

Training organisations often provide a certificate of course completion or course attendance. 

The ratio of Instructors to participants will vary according to the method of delivery and time available for instruction. There is inadequate evidence from formal studies to recommend any particular ratio; the important issue is that all students have adequate time to practice. The precise arrangements will be determined by the number of Instructors and training manikins available. Where these are limited, classes will inevitably take longer to ensure that all participants have sufficient experience to feel confident in the techniques that are learning.

Some DVD methods of delivery require a facilitator rather than an Instructor while others consist entirely of DVD / electronic material and require no Instructor or facilitator. Where non-Instructor methods of delivery are employed it remains important to ensure an adequate ratio of manikins to participants.

Ideally every student should have their own manikin and training AED but resources rarely permit this. Once again, the important point is that every student has adequate time to practise in a simulated environment. Where resources are limited more time will need to be invested to ensure all participants have adequate practice. Where individuals undertake distance learning programmes it is important that they have access to manikins and training AEDs to ensure adequate practical experience.

There is no specific legal requirement for employers to provide defibrillators in the workplace. The Health and Safety Executive’s syllabus of first aid training for offshore installations does include the use of defibrillators, but this is not extended to onshore first aid. However, the Health and Safety (First-Aid) Regulations 1981 do not prevent an employer from providing defibrillators which could benefit both their employees and the public.

For information on workplace health and safety legislation please refer to the Health and Safety Executive’s website.

October 2015