|Why do some airlines carry cardiac defibrillators on their aircraft?|
Cardiac arrest is one of the most common causes of sudden death. It is caused by an abnormal heart rhythm which rapidly stops the heart pumping blood round the body. This usually happens during a heart attack, but can also occur with a number of other heart conditions. If a normal heart rhythm cannot be restored in a few minutes, the person will die. It may be possible to keep the person alive by giving them life support (CPR - cardiopulmonary resuscitation), but usually a normal heart rhythm can only be restored by using a heart ‘defibrillator’.
The heart muscle has to contract in a regular and coordinated way to pump blood around the body. ‘Ventricular fibrillation’ is the most common cause of a cardiac arrest and it leads to the heart muscle beating in a completely irregular and uncoordinated way. A defibrillator causes an electrical shock to be passed through the body, which will often change a fibrillating heart to a normally beating one.
The cardiac defibrillators that are carried on aircraft, and are sometimes seen in other public places such as train stations, shopping centres and sports grounds, are known as ‘automated external defibrillators’ or ‘AEDs’. They are very simple to use and once attached to a person are able to automatically detect the heart rhythm and decide if a shock is needed. They are also very safe to use, as they will only allow a shock to be given if it is necessary. Non-medical people can be trained to use them as part of a first aid or life support training course.
Every year a small number of people collapse and die when travelling on aircraft and some of them will have had a cardiac arrest. Some airlines have chosen to carry AEDs and to train their cabin crew to use them, in the hope that some of these lives can be saved.
Why isn’t it compulsory for airlines to carry a defibrillator on an aircraft?
All airlines are legally required to train their cabin crew in first aid and to carry first aid kits on their aircraft. However, there is no legal requirement for them to carry defibrillators and some people have suggested that the regulations should be changed to make this compulsory.
Cases of sudden cardiac arrest are very rare when compared to the number of passengers. The evidence from those airlines that have been carrying defibrillators is that although a few lives are saved, in most cases the use of a defibrillator is not successful. This is partly because some of the cases are not due to ventricular fibrillation and a defibrillator will not be able to restore a normal rhythm. Also, even if a normal heart rhythm can be restored, the cause of the abnormal rhythm – such as a heart attack – cannot be treated until the person gets to hospital and this can take several hours.
Although defibrillators are now more commonly found in public places, they are not a legal requirement even in places where large numbers of people gather. There is no evidence that airline passengers are at increased risk of sudden cardiac arrest and most authorities do not consider that it would be justified to make it compulsory for all aircraft to carry defibrillators.