Is it safe to use an AED on a child?

Yes. The incidence of shockable rhythms requiring defibrillation in children is very low but can occur. The priority must always be for high-quality CPR and getting expert help. However, the AED can be used across all age groups if this is the only available machine.

The paediatric advanced life support Guidelines 2015 state that if using an AED on a child of less than eight years, a paediatric attenuated shock energy should be used if possible. 

Experience with the use of AEDs (preferably with dose attenuator) in children younger than one year is limited. The use of an AED is acceptable if no other option is available as, on balance, it is probably better to give a 50 J shock than nothing at all. The upper safe limit for dosage in this group is unknown.