The Importance of CPR in Sudden Cardiac Arrest
By Adrian Waller, Public Safety Manager, ZOLL.
Sudden Cardiac Arrest SCA is an indiscriminate killer with a dismal survival rate of between 5 and 7%. While half the victims are elderly and over the age of 67, SCA can strike younger victims, including those appearing to be in excellent health, athletes and even young children. It’s the leading cause of death worldwide and is responsible for over 150,000 deaths a year in the United Kingdom alone. SCA is not the same as a heart attack (acute myocardial infarction or AMI). A heart attack is caused by a blockage in an artery that supplies blood to the heart. The affected heart muscle then begins to die due to lack of oxygen. Symptoms include central crushing chest pain, often radiating to arms and jaw. The patient, however usually remains awake and alert. A heart attack can degenerate into Ventricular Fibrillation when the victim becomes totally unresponsive. The Resuscitation Guidelines 2005 state that the optimum treatment for sudden cardiac arrest or ventricular fibrillation is immediate good quality CPR (Cardio Pulmonary Resuscitation) and electrical “defibrillation” delivered by Compressions within Guidelines.
With Real CPR Help using and AED (Automated External Defibrillator). Several recent studies have also indicated that approximately 50% of SCA victims at the time of the first heart rhythm analysis have deteriorated into aystole or a non- shockable rhythm, where then the only effective treatment becomes good quality CPR, which can reconvert the heart back to ventricular fibrillation to enable the AED to delivery the essential defibrillatory shock.
The resuscitation guidelines 2005 clearly highlight the critical importance of high-quality uninterrupted chest compressions on the survival of the sudden cardiac arrest patient.When a rescuer attempts to deliver CPR, Interruptions to chest compressions must be minimized. As stopping CPR the blood flow through the body decreases significantly; on resuming chest compressions, several compressions are necessary before the coronary flow recovers to its previous level. Recent evidence indicates that unnecessary interruptions to chest compressions occur frequently both in and out of hospital. What does CPR do? CPR provides a small but critical amount of blood to the heart and the brain. CPR can prolong the time VF is present and increases the likelihood that a shock will terminate VF and allow the heart to resume an effective rhythm and effective systemic perfusion.
CPR is especially important if defibrillation isn’t delivered for four or more minutes after a collapse. By that time, the heart has become distended because it has stopped pumping, yet the veins continue delivering blood to the heart. CPR helps evacuate this blood, which significantly increases the chances it will be effective. All victims of SCA need immediate CPR. The principal reason to do CPR is that it helps pump oxygenated blood to the heart; in and of itself, it can bring a person back to life. The 2005 Resuscitation Guidelines elevated CPR as an essential part of the rescue, stating that CPR is critical if an AED advises “No Shock” and in the event a shock is advised, it must be accompanied by good quality CPR.
The 2005 Guidelines made significant changes to the rescue and AED protocols. There was unanimous support for increased emphasis on ensuring that rescuers deliver high-quality CPR, which is what rescuers need to provide.
In all, the 2005 Guidelines reinforce that continuous chest compressions keep perfusion up so the heart, brain and other vital organs get more oxygenated blood together with defibrillation will increase the chance of Return Of Spontaneous Circulation (ROSC) and note that all interruptions are bad because they stop perfusion.
The provision of AED’s in the work place and wider community has been rapidly increasing over the last few years and it is estimated that there are over 10,000 deployed across the UK. The technology used in AED’s has made them easy to use with a minimum amount of training. The real issue is however whether or not the AED will advise shock at the time when you are going to use it and equally as important are you able to deliver the high quality CPR required for a prolonged period of time. The ZOLL AED Plus is unique, in so much that it not only delivers the defibrillatory shock if required, but also it also fully supports the rescuers attempt to deliver good quality CPR. Utilizing a system known as “Real CPR Help®”, this has now become a standard feature across the entire range of all ZOLL’s defibrillators. This gives the rescuer the best real-time feedback to optimize the patient’s opportunity for a return to spontaneous circulation.
Real CPR Help is constantly looking at the delivery of chest compressions and will assist all rescuers with the following feedback and prompting for help in providing effective manual CPR.
For training see www.profaw.co.uk or find an approved instructor at www.first-aid-junction.co.uk. Zoll AED units, Trainers and instructor training, please see ITG First Aid and ITG First Aid Instructor Training