Cardiac arrest, (also known as cardiopulmonary arrest or circulatory arrest) is the cessation of normal circulation of the blood due to failure of the heart to contract effectively. Medical personnel can refer to an unexpected cardiac arrest as a sudden cardiac arrest or SCA.
A cardiac arrest is different from (but may be caused by) a heart attack, where blood flow to the muscle of the heart is impaired
Arrested blood circulation prevents delivery of oxygen to the body. Lack of oxygen to the brain causes loss of consciousness, which then results in abnormal or absent breathing. Brain injury is likely if cardiac arrest goes untreated for more than five minutes. For the best chance of survival and neurological recovery, immediate and decisive treatment is imperative.
Cardiac arrest is a medical emergency that, in certain situations, is potentially reversible if treated early. When unexpected cardiac arrest leads to death this is calledsudden cardiac death (SCD). The treatment for cardiac arrest is cardiopulmonary resuscitation (CPR) to provide circulatory support, followed by defibrillation if a shockable rhythm is present. If a shockable rhythm is not present after CPR and other interventions, clinical death is inevitable.
CPR is a critical part of the management of cardiac arrest. It should be started as soon as possible and interrupted as little as possible. The component of CPR which seems to make the greatest difference is thechest compressions. Tracheal intubation has not been found to improve survival rates in cardiac arrest cases. A 2009 study has found that assisted ventilation may worsen outcomes over placement of an oral airway with passive oxygen delivery. Intubation in the prehospital environment has been found to decrease survival. Correctly performed bystander CPR has been shown to increase survival; it is performed in less than 30% of out of hospital arrests.
Shockable and non–shockable causes of cardiac arrest is based on the presence or absence of ventricular fibrillation or pulseless ventricular tachycardia. The shockable rhythms are treated with CPR and defibrillation.
In addition, there is increasing use of public access defibrillation. This involves placing automated external defibrillators in public places, and training staff in these areas how to use them. This allows defibrillation to take place prior to the arrival of emergency services, and has been shown to lead to increased chances of survival. Some defibrillators even provide feedback on the quality of CPR compressions, encouraging the lay rescuer to press the patient’s chest hard enough to circulate blood. In addition, it has been shown that those who suffer arrests in remote locations have worse outcomes following cardiac arrest: these areas often have first responders, whereby members of the community receive training in resuscitation and are given a defibrillator, and called by the emergency medical services in the case of a collapse in their local area.
Medications, while included in guidelines, have been shown not to improve survival to hospital discharge post out of hospital cardiac arrest. This includes the use of epinephrine, atropine, and amiodarone. Epinephrine does however increase return of spontaneous circulation and there is a non-significant trend towards improvement in long term survival. World Heart Association has removed its recommendation for using atropine in pulseless electrical activity and asystole.
A cardiac arrest & heart attack: What’s the difference?
Cardiac arrest is an abrupt cessation of pump function in the heart (as evidenced by the absence of a palpable pulse). Prompt intervention can usually reverse a cardiac arrest, but without such intervention it will almost always lead to death. In certain cases, it is an expected outcome to a serious illness.
However, due to inadequate cerebral perfusion, the patient will be unconscious and will have stopped breathing. The main diagnostic criterion to diagnose a cardiac arrest, (as opposed to respiratory arrest which shares many of the same features), is lack of circulation, however there are a number of ways of determining this. Near death experiences are reported by 10-20% of people who survived cardiac arrest.
A heart attack is the constriction of blood to the heart muscle caused by blocked arteries, commonly linked to unhealthy lifestyles and old age. A cardiac arrest is totally different and can occur in the young and healthy if the heart goes into a dangerous rhythm, unable to pump blood around the body.
World of football in SHOCK last week following a players from Bolton Wanderers been critically ill after doctor classified it as Cardiac arrest.
Coronary heart disease is the leading cause of sudden cardiac arrest. Many other cardiac and non-cardiac conditions also increase ones risk.
Cardiac arrest is synonymous with clinical death. A cardiac arrest is usually diagnosed clinically by the absence of a pulse. In many cases lack of carotid pulse is the gold standard for diagnosing cardiac arrest, but lack of a pulse (particularly in the peripheral pulses) may be a result of other conditions (e.g. shock), or simply an error on the part of the rescuer. Studies have shown that rescuers often make a mistake when checking the carotid pulse in an emergency, whether they are healthcare professionals or lay persons.
The technique should be used only by healthcare professionals with specific training and expertise, and even then that it should be viewed in conjunction with other indicators such as agonal respiration.
Rescuers to look for “signs of circulation”, but not specifically the pulse. These signs included coughing, gasping, colour, twitching and movement. However, in face of evidence that these guidelines were ineffective, mthat cardiac arrest should be diagnosed in all casualties who are unconscious and not breathing normally.
Positive outcomes following cardiac arrest unlikely, an effort has been spent in finding effective strategies to prevent cardiac arrest. With the prime causes of cardiac arrest being ischemic heart disease, efforts to promote a healthy diet, exercise, and smoking cessation are important. For people at risk of heart disease, measures such as blood pressure control, cholesterol lowering, and other medico-therapeutic interventions are used.
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