Cardiopulmonary ResuscitationEdit
Cardiopulmonary resuscitation (CPR) is a set of life-saving techniques intended to preserve brain function and maintain blood circulation when the heart or lungs have stopped working. The goal is to sustain oxygen delivery to vital organs until normal heart function can be restored or until a decision about care is made. Over the decades, CPR has evolved from simple mouth-to-mouth rescue breathing to a structured set of steps that often emphasizes chest compressions and early defibrillation, while still recognizing the value of breaths in many situations. Cardiopulmonary resuscitation has become a core component of emergency medicine and is routinely taught to laypeople and professionals alike through organizations such as the American Heart Association and the European Resuscitation Council.
Historically, the modern practice of CPR emerged in the mid-20th century through the work of researchers and clinicians who demonstrated that circulating blood, via chest compressions, and providing oxygen can keep a beating heart and brain viable long enough for medical treatment to resume. The field has since matured into a coordinated system that spans Emergency medical services, hospital care, and community training, with ongoing refinements in technique, equipment, and guidelines issued by international bodies like the International Liaison Committee on Resuscitation and translated into national recommendations by bodies such as the American Heart Association and the European Resuscitation Council.
Overview
Definition and purpose
CPR is used in situations where the patient experiences cardiac arrest or a severe respiratory arrest, resulting in a cessation of effective blood flow. The procedure aims to maintain cerebral and myocardial perfusion, thereby increasing the chances of a successful return of spontaneous circulation (ROSC) and reducing the risk of permanent organ damage. The core components include chest compressions to generate circulation, airway management to support breathing, and, when appropriate, rescue breaths or defibrillation with an automated external defibrillator (AED). See also Out-of-hospital cardiac arrest and In-hospital cardiac arrest for context on where CPR is delivered.
Physiology and mechanism
During cardiac arrest, the heart fails to pump effectively, and oxygen delivery to tissues falls precipitously. Chest compressions create a surrogate circulation that can deliver a limited amount of blood to the brain and heart. Oxygen present in the blood at the moment of collapse can help sustain tissues during the first critical minutes, while ventilation helps maintain gas exchange. When a shockable rhythm is present, defibrillation with an AED or manual defibrillator can restore electrical activity of the heart and improve the likelihood of ROSC. See Pulmonary physiology and Cardiac arrest for related topics.
Settings: OHCA vs IHCA
The settings of CPR differ in the field (out-of-hospital) versus the hospital. In OHCA, lay bystanders, EMS, and AEDs in public spaces play a decisive role in early intervention. In IHCA, hospital staff, monitors, and rapid escalation to advanced life support (ALS) protocols influence outcomes. See Bystander CPR and Advanced life support for details.
Techniques and protocols
Basic Life Support (BLS)
BLS refers to the foundational steps used by lay rescuers and first responders. The typical sequence emphasizes high-quality chest compressions at a rate of about 100–120 compressions per minute, with a depth sufficient to produce visible chest rise and recoil between compressions. Compression-only CPR is recommended for untrained bystanders or when rescue breaths are not feasible. If trained and able, a rescue breath component is added, following established ventilation ratios. AEDs should be retrieved and applied as soon as available. See Basic life support and Automated external defibrillator for related topics.
Advanced Life Support (ALS) and hospital care
ALS involves airway management, intubation when appropriate, continuous chest compressions, vascular access, and administration of medications (for example, vasopressors such as epinephrine and antiarrhythmic drugs when indicated). It also covers post-resuscitation care, including targeted temperature management and hemodynamic optimization. See Advanced life support and Targeted temperature management for related topics.
Defibrillation and rhythm management
Defibrillation is a critical step when the rhythm is shockable (such as ventricular fibrillation or pulseless ventricular tachycardia). An AED or advanced defibrillator delivered promptly can dramatically increase survival chances if applied quickly. See Defibrillation and Ventricular fibrillation for more.
Airway, ventilation, and oxygen
Airway management ranges from simple adjuncts to advanced techniques in hospital settings. Ventilation support is tailored to the patient’s needs, balancing adequate oxygen delivery with minimizing harm from excessive ventilation. See Airway management and Ventilation for broader context.
Training, access, and dissemination
Widespread CPR training—among the general public, schools, and workplaces—improves the likelihood that bystanders will intervene before professional responders arrive. Public access to AEDs is a key component of the chain of survival. See CPR training and Public access defibrillation for related topics.
Outcomes and effectiveness
Survival and neurological outcomes
Survival after cardiac arrest depends on multiple factors, including the time to initiation of CPR, the speed of defibrillation, underlying medical conditions, and the quality of post-resuscitation care. When CPR is started promptly and followed by defibrillation and advanced care, survival with good neurological function is more likely. See Cardiac arrest and Survival after cardiac arrest for related discussions.
Variability and disparities
Outcomes vary by setting, population, and available resources. Regions with rapid EMS response, strong hospital networks, and broad CPR training tend to report better survival rates. Ongoing research seeks to understand and reduce disparities related to age, comorbidities, and access to care. See Health disparities and Emergency medical services for broader context.
Ethics and prognosis
In some cases, physicians and families face difficult decisions about continuing resuscitation when prognosis is poor. Advance directives, do-not-resuscitate (DNR) orders, and patient or family preferences shape care decisions, including the use and intensity of resuscitation efforts. See Do-not-resuscitate order and End-of-life care for related topics.
Controversies and debates
Hands-only CPR vs. traditional CPR with rescue breaths
- In layperson emergencies, evidence supports hands-only chest compressions as an effective first response when breaths are not feasible, while trained responders may provide rescue breaths as appropriate. The balance between simplicity for bystanders and the potential benefit of breaths remains a topic of professional discussion. See Hands-only CPR and Resuscitation guidelines for nuance.
Public access to defibrillators
- The expansion of AEDs in public spaces saves lives by enabling rapid defibrillation, but debates continue about cost, maintenance, and placement in high-traffic areas. Proponents emphasize life-saving potential; critics point to logistical and maintenance concerns in some communities. See Automated external defibrillator and Public health policy for related topics.
Training mandates and community programs
- Policy-makers and medical bodies sometimes discuss whether CPR training should be mandatory in schools or workplaces, and how to fund ongoing training. Supporters argue that greater training improves bystander intervention; opponents raise questions about costs, implementation, and resource allocation. See Public health policy and Education policy for broader context.
Post-resuscitation care and resource use
- Decisions about resource allocation after ROSC, including intensive care and targeted temperature management, can raise questions about quality of life, prognosis, and the appropriate use of expensive therapies in certain patient populations. See Intensive care and End-of-life care for related topics.
Ethical considerations in difficult cases
- There are debates about when to initiate or continue resuscitation in patients with extensive comorbidity or irreversible injury, balancing hope with medical realism and resource stewardship. See Medical ethics and Advance directive for related topics.