Cardiopulmonary resuscitation.

Performing cardiopulmonary resuscitation is a key competency for healthcare professionals. Training in immediate and advanced life support is a requirement for UK doctors; this is depicted in the Foundation training programme competencies and in the Internal Medicine Training curriculum. It requires being able to identify unwell patients, perform a structured assessment and treatment approach, master relevant procedural aspects and demonstrate non-technical skills including leading the resuscitation team. The Resuscitation Council UK has recently provided updated guidance on basic and advanced life support. These guidelines align with similar international guidelines, taking into account evidence from clinical trials of cardiac arrest management and national data on cardiac arrest outcomes in the community and in the hospital. The guidance includes considerations regarding individuals with suspected or confirmed coronavirus disease (COVID-19). The complex ethical aspects around escalation of care, advance care planning, 'Do Not Attempt Cardiopulmonary Resuscitation' decisions and communication with patients and their loved ones are also discussed. This chapter summarizes the current guidance on cardiopulmonary resuscitation.

In the hospital setting, a robust system for identifying deteriorating patients, escalating concerns, getting expert help and acting promptly is paramount to prevent deterioration and cardiac arrest

All hospital staff must be trained in basic life support, while certain staff are required to have up-to-date advanced life support training

The challenges around escalation of care, advance care planning, ‘Do Not Attempt Cardiopulmonary Resuscitation’ decisions and communication with patients and their loved ones are well recognized. The regulatory bodies provide clear guidance on these issues and clinicians should be given training on how to approach such discussions efficiently

The coronavirus disease (COVID-19) pandemic has impacted the practice of resuscitation, and the Resuscitation Council UK has updated the guidance on how to treat patients with suspected or confirmed COVID-19 infection in the community and in hospital settings

Introduction

As defined by the American Heart Association and the American College of Cardiology, ‘cardiac arrest is the sudden cessation of cardiac activity so that the victim becomes unresponsive, with no normal breathing and no signs of circulation. If corrective measures are not taken rapidly, this condition progresses to sudden death. Cardiac arrest should be used to signify an event as described above, which may be reversed, usually by cardiopulmonary resuscitation (CPR) and/or defibrillation or cardioversion, or cardiac pacing’.

According to the Resuscitation Council UK (RCUK), the annual incidence of out-of-hospital cardiac arrest (OHCA) is approximately 55 per 100,000 population, while the annual incidence of in-hospital cardiac arrest (IHCA) is 1–1.5 per 1000 hospital admissions. Bystander CPR is attempted in 7 out of 10 cases of OHCA. The average ambulance response time is reported as 6.9 minutes. The prognosis of OHCA is very poor even when prompt bystander resuscitation is attempted, as only about 9% of patients survive to hospital discharge after OHCA. The statistics are somewhat better for IHCA, as approximately a quarter (23.6%) of those who are treated by the hospital's resuscitation team survive to hospital discharge.

The outcomes of cardiac arrest in the UK are closely monitored by the Out of Hospital Cardiac Arrest Outcomes registry (for OHCA) and the National Cardiac Arrest Audit (for IHCA).

Ethical considerations

The RCUK has produced comprehensive guidance on the ethical issues that surround resuscitation. , These address a variety of areas including advance care planning, patient preferences and choices, communication with patients and families, deciding when to start and when to stop CPR, family presence during resuscitation, acceptable patient outcomes and ‘Do Not Attempt CPR’ (DNACPR).

Advance care planning, which identifies individuals’ wishes and promotes shared decision-making, is crucial. Resuscitation should be discussed with all individuals at increased risk of cardiac arrest or poor outcome in the event of cardiac arrest. It should be addressed along with other treatment decisions such as invasive mechanical ventilation and advance care plans. The RCUK guidance is clear that CPR should not be offered in cases where resuscitation would be futile. Therefore, if a DNACPR decision is made on clear clinical grounds that CPR would not be successful, the clinicians should inform the person of this decision and explain the reason for it. Effective communication during these discussions is paramount, and clinicians should be trained to improve their communication skills in supporting patients to have end-of-life discussions.

Those close to the patient should also be informed unless a patient's wish for confidentiality prevents this. In the case of incapacitated patients, the DNACPR decision should be communicated to those close to them, or the legally appointed representative if there is one. If the decision is not accepted by the individual, their representative or their loved ones, a second opinion should be offered.

When making decisions about CPR, clinicians should aim to explore and understand, where possible, the value that the person places on specific outcomes. The family members or other loved ones should be included in this discussion, with the individual's permission, and can help provide valuable insight into the patient's wishes, especially in the case of incapacitated individuals.

The ReSPECT process (Recommended Summary Plan for Emergency Care and Treatment) is a very helpful tool for clinicians. It creates a summary of personalized recommendations for a person's clinical care in case of an emergency if they lose the capacity to make informed choices. Such choices can include a cardiac arrest but are not limited to this. During the ReSPECT process, the patient and their family have discussions with their healthcare professionals with the aim of understanding what is important to the patient and what is realistic in terms of their care and treatment.

The importance of allowing family members or other loved ones to be present during the resuscitation attempt if they wish to do so has been recognized, and clinicians are advised to offer families this opportunity. Taking a family through this experience is challenging, and clinicians should be given training on how best to provide support.

Guidelines on cardiopulmonary resuscitation

The RCUK recently produced updated guidelines on CPR. These address the whole spectrum of resuscitation, including adult, paediatric and newborn basic and advanced life support (ALS). Similar guidelines are provided by the European Resuscitation Council. The RCUK has also produced quality standards for the management of cardiorespiratory arrest, whether in or out of hospital. These include guidance on the education and training of staff, principles of organization of the ‘resuscitation team’ within hospitals, support on ethical decisions around resuscitation, and promotion of audit and research.

Recognizing the deteriorating patient

Most patients who have an IHCA deteriorate progressively: in approximately 80% of cases there is deterioration of clinical signs during the few hours before the cardiac arrest. Early recognition of the deteriorating patient and prompt treatment may prevent the cardiac arrest. The RCUK has developed a ‘chain of prevention’ of cardiac arrest, a tool to help ensure that deterioration is identified as early as possible, and action is taken to prevent progression into cardiac arrest. It comprises the following elements:

education of staff in assessing and identifying signs of deterioration and how to escalate concerns appropriately

monitoring and patient assessment including measurement of vital signs using the National Early Warning Score (NEWS) or the more comprehensive A–E assessment

recognition of deterioration or any ‘red flags’. This is aided by tools available to identify patients in need of additional monitoring or intervention, including vital signs charts that highlight the need to escalate monitoring or to call for more expert help

call for help protocols for escalating concerns regarding a deteriorating patient being universally known and unambiguous. Hospitals should ensure that all staff feel empowered to ask for help. The use of structured communication tools to call for help is encouraged

response to a deteriorating patient in a timely manner by staff with appropriate skills and expertise who have access to the appropriate equipment being assured.

Establishing treatment escalation plans for all inpatients and considering DNACPR discussions early during the admission process is paramount.

Basic life support (BLS)

The RCUK recently updated the guidelines on basic life support. These highlight the importance of supporting members of our communities to have the confidence, knowledge and skills to act when someone sustains an OHCA. It is more important that people feel able to do something to help than they become focused on small details or concerned about causing harm. No greater harm can occur than failing to act when someone requires CPR and defibrillation. Members of the public should start CPR for presumed cardiac arrest without concerns of causing harm to those not in cardiac arrest. Bystander CPR and use of an automated external defibrillator (AED) increase the chances of survival 2–4-fold and are a critical part of UK government's strategies to improve survival from cardiac arrest.

The recommended adult BLS is shown in Figure 1 . The guidelines suggest that CPR should be initiated in any unresponsive person with absent or abnormal breathing. Slow, laboured breathing (agonal breathing) should be considered a sign of cardiac arrest.

Figure 1

Adult basic life support algorithm 2021. Reproduced with the kind permission of the Resuscitation Council UK.

A lone rescuer with a mobile phone should dial 999, activate the speaker or another hands-free option on the mobile phone and immediately start CPR assisted by the dispatcher. If only one bystander is present and they must leave a victim to ask for help, they should alert the ambulance service first and then start CPR.

Chest compressions should be initiated as soon as possible. Ideally, they should be performed on a firm surface (on the floor rather than on a bed). Chest compressions are delivered on the lower half of the sternum (‘in the centre of the chest’). Compression to a depth of at 5–6 cm at a rate of 100–120 per minute with as few interruptions as possible is recommended, allowing the chest to recoil completely after each compression. If the rescuer is trained to provide rescue breaths, they should alternate between providing 30 compressions and 2 rescue breaths. If they are unable or unwilling to provide ventilation, they should give continuous chest compressions (see the next section).

The location of AEDs can be found on databases available to the ambulance services or a number of apps available to the public. Once the AED is available it should be switched on, the pads should be applied to the bare chest, and the spoken prompts from the AED should be followed. Interruptions to chest compressions should be minimized as much as possible.

For adults and children with a decreased level of responsiveness resulting from medical illness or non-physical trauma who do not meet the criteria for the initiation of CPR, the RCUK recommends they be placed into a lateral, side-lying recovery position.

Compression-only cardiopulmonary resuscitation

Compression-only CPR describes the performance of uninterrupted chest compressions without rescue breathing. In many adults with cardiac arrest the cause of arrest is cardiac rather than respiratory; therefore, breathing will have been normal until the time of arrest and the blood will be well oxygenated. In this situation compression-only CPR can be effective for the first few minutes of resuscitation. Lay bystanders are more likely to attempt compression-only CPR than standard CPR, and the former is technically easier than the latter. The RCUK therefore recommends that if a bystander is more comfortable with compression-only CPR or has not been trained in rescue breaths, they should perform compressions only.

Most cardiac arrests in children follow respiratory arrest. Therefore, ventilation remains a crucial component of CPR in children. However, rescuers who are unable to unwilling to provide rescue breaths should perform at least compression-only CPR, as the child is far more likely to come to harm if the bystander does nothing.

Compression-only CPR is also recommended in patients with suspected or confirmed coronavirus-19 disease (COVID-19) infection (see ‘Resuscitation during the COVID-19 pandemic’).

Advanced life support

The RCUK ALS algorithm is shown in Figure 2 .

Figure 2

Advanced life support algorithm 2021. Reproduced with the kind permission of the Resuscitation Council UK. PaCO2, partial pressure of carbon dioxide in arterial blood; SpO2, blood oxygen saturation.

All hospital staff should be able to rapidly recognize cardiac arrest, call for help, start CPR and defibrillate (using an AED or manual defibrillator). Hospitals use a standard ‘Cardiac Arrest Call’ telephone number (2222). Trained staff should be able to recognize a cardiac arrest in unresponsive patients by opening the airway using standard airway manoeuvres (head tilt, chin lift, jaw thrust) followed by looking, listening, and feeling for a pulse and respiratory effort for up to 10 seconds. However, this step is different in patients with suspected or confirmed COVID-19 infection (see below). CPR is performed at a ratio of 30 chest compressions to 2 ventilations until a definitive airway is established, at which point uninterrupted chest compressions and ventilations can be started. The instructions for the chest compressions are as stated in the BLS section. Uninterrupted ventilations should be delivered at a rate of 10 breaths per minute, while avoiding hyperventilation (excessive rate or tidal volume).

CPR should continue while a defibrillator is retrieved and the pads are applied. The right electrode should be placed in the right subclavicular area, and the left electrode as far into the left axilla as possible. The pads should not be applied directly over an implantable cardiac device (such as a pacemaker). In patients with such devices the pads should be placed at least 8 cm away from the device. Often, an alternative position of the pads should be chosen (such as an antero-posterior position). The function of the device should be checked after successful resuscitation.

The chest compressions are interrupted for checking the rhythm, but the interruption should be minimal (<5 seconds if possible). Further treatment depends on whether the rhythm is shockable or non-shockable. The shockable rhythms are pulseless ventricular tachycardia (pVT) and ventricular fibrillation (VF), while the non-shockable rhythms are pulseless electrical activity (PEA) and asystole.

If the rhythm is shockable, a shock should be delivered as early as possible. Shocks should be delivered with minimal interruption to chest compressions. This is achieved by continuing chest compressions during defibrillator charging, delivering defibrillation with an interruption in chest compressions of <5 seconds and then immediately resuming chest compressions. Chest compressions should not be interrupted until the after rhythm analysis, unless there is a combination of clinical and physiological signs of return of spontaneous circulation (ROSC) such as waking, purposeful movement, an arterial waveform, or a sharp rise in end-tidal carbon dioxide (ETCO2). However, a rise in ETCO2 in isolation should not be used as an indicator to stop CPR.

Delivering safe and effective defibrillation is paramount. Any oxygen mask must be removed and placed at least 1 m away to minimize the risk of fire. Importantly, if the patient is intubated and connected to an oxygen supply, this can remain attached, as in this case the oxygen circuit is closed and defibrillation can be safely performed. All members of the resuscitation team (including the person performing the chest compressions) should be warned to stay clear of the patient during defibrillation, while minimizing interruptions to the chest compressions.

The use of up to three-stacked shocks may be considered if initial VF or pVT occurs during a witnessed, monitored cardiac arrest with a defibrillator immediately available. It can also be considered in the resuscitation of individuals with suspected or confirmed COVID-19 infection (see below). In any other case, an isolated shock should be performed, followed by a 2-minute cycle of CPR. A range of defibrillation energy levels has been recommended by manufacturers and guidelines, ranging from 120 J to 360 J. In the absence of any clear evidence for the optimal initial and subsequent energy levels, any energy level within this range is acceptable for the initial shock, followed by a fixed or escalating strategy up to maximum output of the defibrillator. The members of the resuscitation team should be familiar with the local protocol and adhere to this. For refractory VF, an alternative defibrillation pad position (e.g. anterior-posterior) should be considered.

Intravenous (i.v.) access should be established as soon as possible during the resuscitation attempt. If attempts at i.v. access are unsuccessful, intraosseous (i.o.) access should be considered early.

During the resuscitation of shockable rhythms, adrenaline (epinephrine) 1 mg i.v. (i.o.) should be given after the third shock, and then the same dose should be repeated every 3–5 minutes while ALS continues. After the third shock, amiodarone 300 mg i.v. (i.o.) should also be administered. After the fifth shock, a further dose of amiodarone 150 mg i.v. (i.o.) should be given. Lidocaine 100 mg i.v. (i.o.) can be used as an alternative to amiodarone, with an additional bolus of lidocaine 50 mg after the fifth defibrillation attempt.

In the case of non-shockable rhythms, adrenaline 1 mg i.v. (i.o.) should be administered as soon as possible and should be repeated every 3–5 minutes while resuscitation continues.

It is crucial to recognize and treat possible reversible causes of cardiac arrest. The mnemonic ‘4 H's and 4 T's’ (Hypoxia, Hypovolaemia, Hypo-/hyperkalaemia/metabolic causes, Hypothermia, and Thrombosis – coronary or pulmonary, Tamponade – cardiac, Toxins and drugs, Tension pneumothorax) has been developed to help the resuscitation team. Each of these factors should be considered and treated appropriately if present. With regard to pulmonary embolism, thrombolytic drug therapy should be considered when pulmonary embolus is suspected as the cause of cardiac arrest. It is worth noting that if thrombolysis is administered, CPR should ideally be performed for 60–90 minutes after this, as cases of late recovery have been reported.

Point-of-care ultrasound (POCUS) should be considered if experienced operators are present but it must not cause additional or prolonged interruptions in chest compression. POCUS may be useful to diagnose treatable causes of cardiac arrest such as cardiac tamponade and pneumothorax.

Finally, extracorporeal CPR can be considered if available as a rescue therapy for selected patients with cardiac arrest when conventional ALS measures are failing and to facilitate specific interventions, such as coronary angiography and percutaneous coronary intervention (PCI).

Ventilation and monitoring during resuscitation

Rescuers should start with basic airway techniques and progress stepwise according to their skills until effective ventilation is achieved. Attempts at establishing the airway should be started as soon as the resuscitation is commenced, and their efficacy should be reviewed throughout the resuscitation. The highest feasible oxygen concentration should be delivered during CPR. Once a tracheal tube or a supraglottic airway has been inserted, the lungs can be ventilated at a rate of 10 breaths per minute and continuous chest compressions can be delivered without interruption for ventilation. Tracheal intubation should be attempted only by rescuers with a high tracheal intubation success rate (>95% within two attempts) and should ideally be performed with a less than 5-second interruption in chest compressions.

Waveform capnography should be used to confirm the tracheal tube position and to monitor the patient during resuscitation. It can help monitor the quality of chest compressions, and an increase in ETCO2 may indicate ROSC. Moreover, high and increasing ETCO2 values have a prognostic value as they are associated with increased chance of ROSC and a better outcome after successful resuscitation. However, low ETCO2 values should not be used in isolation to decide whether resuscitation should be stopped.

Resuscitation during the COVID-19 pandemic

The RCUK guidelines for the resuscitation of individuals with suspected or confirmed COVID-19 infection are different from the traditional BLS and ALS protocols. This is because chest compressions and airway instrumentation are aerosol-generating procedures (AGPs) so appropriate personal protective equipment (PPE) must be worn during these. The need to don PPE may delay CPR, but the resuscitation team's safety is paramount.

The RCUK guidelines for first aid and community services advise that cardiac arrest should be recognized by looking for an absence of signs of life and an absence of normal breathing. Listening or feeling for breath by approaching the patient's mouth is not advised in this case. When calling the ambulance, bystanders should inform the ambulance service of the risk of COVID-19. The rescuers should place a cloth or towel over the patient's mouth and nose, and perform compression-only CPR and early defibrillation. If the rescuers have access to any form of PPE, this should be worn.

The guidelines advise that, in children, rescue breaths should be attempted if possible, as the cause of cardiac arrest in children is most likely to be respiratory, and chest compressions alone are unlikely to be effective, acknowledging the fact that this will increase the risk of transmission of COVID-19. However, the guidelines highlight that it is likely that the child or infant will be known to the rescuer and that the risk of transmitting the virus is small compared with the risk of taking no action.

Resuscitation in patients with suspected or confirmed COVID-19 within hospital settings is described in Figure 3 . The resuscitation team should also be familiar with the local trust protocols. It is imperative to identify individuals with a COVID-19-like illness at risk of deterioration and take all the appropriate steps to prevent a cardiac arrest. Patients for whom resuscitation is not appropriate should also be identified early, and a DNACPR order should be discussed with the individual and their family.

Figure 3

Reproduced with the kind permission of the Resuscitation Council UK. ET, endotracheal; HCW, healthcare worker.

With regards to recognizing cardiac arrest, healthcare workers without appropriate PPE for AGP can feel for a pulse if they are trained to do so, but they should not listen or feel for breathing as per traditional guidance. When calling 2222 to talk to the cardiac arrest team, the risk of COVID-19 infection should be stated.

If a defibrillator is readily available, shockable rhythms should be defibrillated before starting chest compressions, while the team is getting ready. Full AGP PPE must be worn by all members of the resuscitation team before entering the room. Chest compressions and airway procedures should only be performed with full PPE. Once the resuscitation team is wearing appropriate PPE, compression-only CPR should be started. Mouth-to-mouth ventilation or use of a pocket mask should be avoided. Airway interventions can be performed as per guidelines with appropriate PPE on.

PPE should be removed cautiously at the end of the resuscitation attempt and the equipment used should be meticulously cleaned.

Post-resuscitation care

Optimized care after ROSC plays a primordial role in the person's survival. They should immediately be reassessed using the A–E approach. Blood pressure should be supported if necessary, aiming for a mean blood pressure of 65–80 mmHg; invasive blood pressure monitoring should be considered. ROSC can often be followed by a systemic inflammatory syndrome and multiorgan failure, so the individual should be closely monitored. Neuroprotection should be considered with targeted temperature management and prompt treatment of seizures, arrhythmias, hypotension and hyperglycaemia. If ST elevation myocardial infarction (STEMI) is identified as the cause of the arrest, the patient should be considered for emergency PCI. PCI outside the context of STEMI is controversial and requires careful consideration.

National policies increasingly promote the development of designated cardiac arrest centres, which have expertise in the treatment of cardiac arrest patients and accept all the patients after OHCA.

Human factors and quality in resuscitation

The importance of non-technical skills in the outcome of resuscitation has been very well established. The main non-technical skills at play during resuscitation are situational awareness, decision-making and team-working, including team leadership and task management. Efficient resuscitation depends on efficient team skills, with every member of the team performing their task in harmony with the others. A skilled team leader should be able to step back, maintain awareness of the changing environment at every step of the resuscitation, integrate new information and make decisions accordingly. In a well-functioning team, all members have a common understanding of current events or a shared situational awareness. This requires effective communication, with the relevant information shared in a clear way.

When to stop

The decision to withhold or stop resuscitation is often challenging. Situations when the safety of the provider cannot be assured, there is obvious mortal injury or irreversible death, or there is a valid and relevant advance decision against CPR are considered unequivocal criteria against starting CPR. In the absence of any of these, an initial presumption in favour of attempting CPR should be made. CPR providers often face situations when a discontinuation of CPR is considered. Such situations include persistent asystole despite 20 minutes of ALS in the absence of any reversible cause, unwitnessed cardiac arrest with an initial non-shockable rhythm, individuals whose chance of survival with any meaningful quality of life is minimal, such as those with advanced co-morbidities, or situations when further CPR would not be consistent with the patient's values and wishes or in their best interests. The resuscitation team should ideally reach a consensus to stop CPR, and the reason for stopping CPR should be clearly documented.