Frequently asked questions

Q.  How can I get the code to open the AED cabinet if my mobile phone has no signal at that location?
A.  If you call '999' or '112' your mobile will connect to any network for the purposes of the emergency call.

Q.  Do all of our AED locations have a mobile service from at least one provider?
A.  Yes.  In fact, all five of our locations have mobile phone signals from at least three operators.  These vary in strength.  For results of our tests please see our Useful Info.

Q.  What is ventricular fibrillation? 
A.  Ventricular fibrillation is the fatal rhythm that causes sudden cardiac arrest. The heart instantly goes from a normal heart rhythm to a chaotic rhythm called ventricular fibrillation. When the heart goes into VF, the pulse and blood pressure is instantly lost and the person loses consciousness in a few seconds. The only effective treatment is an electric shock across the chest and through the heart. A shock, if delivered in time, can convert the fatal rhythm of VF back to a normal heart rhythm. An AED is a device that automatically analyses the heart’s rhythm and can deliver a shock if VF is present.

Q.  What is the difference between CPR and an AED?
A.  CPR cannot convert VF into a normal rhythm (only an electric shock can do this) but CPR can circulate a small trickle of oxygenated blood to vital organs and thus slow the dying process until an AED arrives. Thus CPR buys time until the AED arrives to deliver a shock.

Q.  How soon must I attach an AED to a person in cardiac arrest? 
A.  The sooner the better. The chances of a successful defibrillation using an AED falls by about 20% with each passing minute.  Therefore the device should be deployed within 5 minutes of the cardiac arrest.

Q.  Can I use an AED on a child?
A.  Yes.  Although some AED's have a paediatric/adult switch Community Heartbeat Trust do not recommend them since there have been instances of a paediatric shock being delivered to an adult which had no effect.  For similar reasons paediatric electrode pads are not supplied as the weight of the child can affect the usefulness of the shock regardless of the patient being within the stated age range.  Use the supplied AED but on a child place the pads on the chest and back.

Q.  Why do I call 999 before attaching the AED? 
A.  If there are two witnesses to the cardiac arrest, one should call 999 while the other retrieves and attaches the AED.  If there is only one rescuer, that person should call 999 in order to get the Ambulance Service responding to the scene. It is worth the extra minute to get help on the way. The emergency operator can tell you how to perform CPR if you have forgotten.  Once the AED arrives, even if you are successful, then Ambulance Service personnel will have to administer medications (to prevent a relapse into VF) and give oxygen or even place a breathing tube down the person’s windpipe.

Q.  What if the AED doesn’t give a shock? 
A.  Not every cardiac arrest is caused by VF. Approximately one third of the time the heart will not be in VF and therefore the AED will not deliver a shock. In this case it will advise the rescuer to check the patient and begin CPR.

Q.  What happens if I am touching the person when the AED shocks? 
A.  Probably nothing. You may feel a slight tingle. Try to not touch the person when the shock is delivered. If you should have latex gloves available, this should also protect you even if you are touching the patients chest at the moment of shock.

Q.  What if the victim is wet or lying on a wet surface? 
A.  Try to dry the chest with a towel before applying the pads. Defibrillation is most safely performed on a dry surface. The risks to rescuers and bystanders associated with defibrillating on a wet surface have to be balanced against the risk to the patient of delaying defibrillation. If the patient cannot be safely and quickly moved to a dry surface, as far as possible all bystanders should move off the wet surface. Anyone that must be on the wet surface should avoid direct contact with the patient, and should avoid contact between their body - particularly above their waist - and the wet surface, as far as possible. Wearing latex gloves will also reduce the likelihood of the rescuer being shocked in the event the rescuer is touching the patient at the moment of defibrillation.

Q.  What if the chest is hairy and the pads won’t stick to the skin? 
A.  There is a disposable razor in the green rescue pouch in the back pocket of the AED case.  It is just for this purpose.

Q.  Can the AED accidentally shock someone who doesn’t need a shock? 
A.  Not likely. The AED is designed to only shock VF. It will not shock any other heart rhythm. Nevertheless, AEDs are not perfect and in 1% of cases it may shock a rhythm other than VF. That’s why it should only be attached to a person who is unconscious and has collapsed.

Q.  What if the victim has a pacemaker? 
A.  Ignore the presence of the pacemaker.

Q.  What do I do if the AED works and the victim starts to wake up? 
A.  That’s great. Unless the person tries to sit up, place the victim on his or her side (the recovery position) so saliva can drain out without blocking the airway.

Q.  Do I have to place the pads in the exact spot shown in the diagram? 
A.  As close as possible. When the pads are in the incorrect location the shock is less effective.

Q.  What if the woman has a bra on? 
A.  Lift the bra up over the breasts and let it bunch up around the neck, then attach the pads.

Q.  Will an AED save everyone in cardiac arrest? 
A.  No. Many factors such as whether the collapse was witnessed, the heart’s rhythm, and the underlying condition of the victim determine whether the victim lives or dies.

Thanks to Dr Mickey Eisenberg, Professor, Medical Director, King County Emergency Medical Services Division for supplying some of these FAQ's from his website Learn AED