Return of spontaneous circulation (ROSC) is the resumption of a sustained heart rhythm that perfuses the body after cardiac arrest. It is commonly associated with significant respiratory effort. Signs of return of spontaneous circulation include breathing, coughing, or movement and a palpable pulse or a measurable blood pressure. Someone is considered to have sustained return of spontaneous circulation when circulation persists and cardiopulmonary resuscitation has ceased for at least 20 consecutive minutes. [1]
There are multiple factors during cardiopulmonary resuscitation (CPR) and defibrillation that are associated with success of achieving return of spontaneous circulation. One of the factors in CPR is the chest compression fraction, which is a measure of how much time during cardiac arrest are chest compressions performed. A study measured the effects of chest compression fraction on return of spontaneous circulation in out-of-hospital cardiac arrest patients with a non-ventricular fibrillation arrhythmia and it showed a trend to achieving return of spontaneous circulation with an increased chest compression fraction. [2] Another study highlighted the benefits of minimizing chest compression intervals before and after shocking a patient's rhythm, which would in turn increase chest compression fraction. [3] A coronary perfusion pressure of 15 mmHg is thought to be the minimum necessary to achieve ROSC. [4]
Pertaining to defibrillation, the presence of a shockable rhythm (ventricular fibrillation or pulseless ventricular tachycardia) is associated with increased chances of return of spontaneous circulation. [5] Although a shockable rhythm increases chances for return of spontaneous circulation, a cardiac arrest can present with pulseless electrical activity or asystole, which are non-shockable cardiac rhythms. [6]
Return of spontaneous circulation can be achieved through cardiopulmonary resuscitation and defibrillation. Though ROSC is necessary for survival, it is not, itself, a predictor of a favorable medium- or long-term outcome. [7] Patients have died not long after their circulation has returned. One study showed that those who had had an out-of-hospital cardiac arrest and had achieved return of spontaneous circulation, 38% of those people had a cardiac re-arrest before arriving at the hospital with an average time of 3 minutes to re-arrest. [8] Patients with sustained ROSC generally present with post-cardiac arrest syndrome (PCAS). Longer time-to-ROSC is associated with a worse presentation of PCAS. [9]
Lazarus phenomenon is the rare spontaneous return of circulation after cardiopulmonary resuscitation attempts have stopped in someone with cardiac arrest. This phenomenon most frequently occurs within 10 minutes of cessation of resuscitation, thus passive monitoring is recommended for 10 minutes following CPR cessation. [10]
Cardiac arrest, also known as sudden cardiac arrest, is when the heart suddenly and unexpectedly stops beating. As a result, blood cannot properly circulate around the body and there is diminished blood flow to the brain and other organs. When the brain does not receive enough blood, this can cause a person to lose consciousness. Coma and persistent vegetative state may result from cardiac arrest. Cardiac arrest is also identified by a lack of central pulses and abnormal or absent breathing.
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation, or mouth to mouth in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is recommended for those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations.
Cardioversion is a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs. Synchronized electrical cardioversion uses a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle, restoring the activity of the electrical conduction system of the heart. Pharmacologic cardioversion, also called chemical cardioversion, uses antiarrhythmia medication instead of an electrical shock.
Advanced cardiac life support, advanced cardiovascular life support (ACLS) refers to a set of clinical guidelines established by the American Heart Association (AHA) for the urgent and emergent treatment of life-threatening cardiovascular conditions that will cause or have caused cardiac arrest, using advanced medical procedures, medications, and techniques. ACLS expands on Basic Life Support (BLS) by adding recommendations on additional medication and advanced procedure use to the CPR guidelines that are fundamental and efficacious in BLS. ACLS is practiced by advanced medical providers including physicians, some nurses and paramedics; these providers are usually required to hold certifications in ACLS care.
Defibrillation is a treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation (V-Fib) and non-perfusing ventricular tachycardia (V-Tach). A defibrillator delivers a dose of electric current to the heart. Although not fully understood, this process depolarizes a large amount of the heart muscle, ending the arrhythmia. Subsequently, the body's natural pacemaker in the sinoatrial node of the heart is able to re-establish normal sinus rhythm. A heart which is in asystole (flatline) cannot be restarted by a defibrillator; it would be treated only by cardiopulmonary resuscitation (CPR) and medication, and then by cardioversion or defibrillation if it converts into a shockable rhythm.
Ventricular fibrillation is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and no pulse. This is followed by sudden cardiac death in the absence of treatment. Ventricular fibrillation is initially found in about 10% of people with cardiac arrest.
Asystole is the absence of ventricular contractions in the context of a lethal heart arrhythmia. Asystole is the most serious form of cardiac arrest and is usually irreversible. Also referred to as cardiac flatline, asystole is the state of total cessation of electrical activity from the heart, which means no tissue contraction from the heart muscle and therefore no blood flow to the rest of the body.
An automated external defibrillator or automatic electronic defibrillator (AED) is a portable electronic device that automatically diagnoses the life-threatening cardiac arrhythmias of ventricular fibrillation (VF) and pulseless ventricular tachycardia, and is able to treat them through defibrillation, the application of electricity which stops the arrhythmia, allowing the heart to re-establish an effective rhythm.
Basic life support (BLS) is a level of medical care which is used for patients with life-threatening condition of cardiac arrest until they can be given full medical care by advanced life support providers. It can be provided by trained medical personnel, such as emergency medical technicians, qualified bystanders and anybody who is trained for providing BLS and/or ACLS.
Precordial thump is a medical procedure used in the treatment of ventricular fibrillation or pulseless ventricular tachycardia under certain conditions. The procedure has a very low success rate, but may be used in those with witnessed, monitored onset of one of the "shockable" cardiac rhythms if a defibrillator is not immediately available. It should not delay cardiopulmonary resuscitation (CPR) and defibrillation, nor should it be used in those with unwitnessed out-of-hospital cardiac arrest.
Pulseless electrical activity (PEA) is a form of cardiac arrest in which the electrocardiogram shows a heart rhythm that should produce a pulse, but does not. Pulseless electrical activity is found initially in about 20% of out-of-hospital cardiac arrests and about 50% of in-hospital cardiac arrests.
ABC and its variations are initialism mnemonics for essential steps used by both medical professionals and lay persons when dealing with a patient. In its original form it stands for Airway, Breathing, and Circulation. The protocol was originally developed as a memory aid for rescuers performing cardiopulmonary resuscitation, and the most widely known use of the initialism is in the care of the unconscious or unresponsive patient, although it is also used as a reminder of the priorities for assessment and treatment of patients in many acute medical and trauma situations, from first-aid to hospital medical treatment. Airway, breathing, and circulation are all vital for life, and each is required, in that order, for the next to be effective: a viable Airway is necessary for Breathing to provide oxygenated blood for Circulation. Since its development, the mnemonic has been extended and modified to fit the different areas in which it is used, with different versions changing the meaning of letters or adding other letters.
Commotio cordis is a rare disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart at a critical instant during the cycle of a heartbeat. The condition is 97% fatal if not treated within three minutes. This sudden rise in intracavitary pressure leads to disruption of normal heart electrical activity, followed instantly by ventricular fibrillation, complete disorganization of the heart's pumping function, and cardiac arrest. It is not caused by mechanical damage to the heart muscle or surrounding organs and is not the result of heart disease.
The AutoPulse is an automated, portable, battery-powered cardiopulmonary resuscitation device created by Revivant and subsequently purchased and currently manufactured by ZOLL Medical Corporation. It is a chest compression device composed of a constricting band and half backboard that is intended to be used as an adjunct to CPR during advanced cardiac life support by professional health care providers. The AutoPulse uses a distributing band to deliver the chest compressions. In literature it is also known as LDB-CPR.
The chain of survival refers to a series of actions that, properly executed, reduce the mortality associated with sudden cardiac arrest. Like any chain, the chain of survival is only as strong as its weakest link. The six interdependent links in the chain of survival are early recognition of sudden cardiac arrest and access to emergency medical care, early CPR, early defibrillation, early advanced cardiac life support, and physical and emotional recovery. The first three links in the chain can be performed by lay bystanders, while the second three links are designated to medical professionals. Currently, between 70 and 90% of cardiac arrest patients die before they reach the hospital. However, a cardiac arrest does not have to be lethal if bystanders can take the right steps immediately.
The history of cardiopulmonary resuscitation (CPR) can be traced as far back as the literary works of ancient Egypt. However, it was not until the 18th century that credible reports of cardiopulmonary resuscitation began to appear in the medical literature.
Coronary perfusion pressure (CPP) refers to the pressure gradient that drives coronary blood pressure. The heart's function is to perfuse blood to the body; however, the heart's own myocardium must, itself, be supplied for its own muscle function. The heart is supplied by coronary vessels, and therefore CPP is the blood pressure within those vessels. If pressures are too low in the coronary vasculature, then the myocardium risks ischemia with subsequent myocardial infarction or cardiogenic shock.
Rearrest is a phenomenon that involves the resumption of a lethal cardiac dysrhythmia after successful return of spontaneous circulation (ROSC) has been achieved during the course of resuscitation. Survival to hospital discharge rates are as low as 7% for cardiac arrest in general and although treatable, rearrest may worsen these survival chances. Rearrest commonly occurs in the out-of-hospital setting under the treatment of health care providers.
The Lund University Cardiopulmonary Assist System (LUCAS) device provides mechanical chest compressions to patients in cardiac arrest. It is mostly used in emergency medicine as an alternative to manual CPR because it provides consistent compressions at a fixed rate through difficult transport conditions and eliminates the physical strain on the person performing CPR. The first generation of the LUCAS device was pneumatic, while the second and third generations are battery-operated.
Post-cardiac arrest syndrome (PCAS) is an inflammatory state of pathophysiology that can occur after a patient is resuscitated from a cardiac arrest. While in a state of cardiac arrest, the body experiences a unique state of global ischemia. This ischemia results in the accumulation of metabolic waste which instigate the production of inflammatory mediators. If return of spontaneous circulation (ROSC) is achieved after CPR, then circulation resumes, resulting in global reperfusion and the subsequent distribution of the ischemia products throughout the body. While PCAS has a unique cause and consequences, it can ultimately be thought of as type of global ischemia-reperfusion injury. The damage, and therefore prognosis, of PCAS generally depends on the length of the patient's ischemic period; therefore the severity of PCAS is not uniform across different patients.