Reviewed October 2026 — ERC 2025 and AHA 2025 resuscitation guidelines. This replaces a historical 2015 AED buying guide. Device photographs below are retained for illustration, not as a current model comparison or purchasing recommendation.
What is an AED?
An automated external defibrillator (AED) is designed for suspected cardiac arrest. It analyses the rhythm and advises or delivers a shock when appropriate, mainly for ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT). It is not used to cardiovert atrial fibrillation or atrial flutter; these are managed with different devices/protocols when cardioversion is indicated. Asystole and pulseless electrical activity are non-shockable rhythms.
How to respond to suspected cardiac arrest
- Ensure safety and call emergency services (112 in much of Europe, including Switzerland). If a person is unresponsive, call immediately and assess breathing with dispatcher assistance. Abnormal or gasping breathing is not normal breathing.
- Start CPR. Give chest compressions at 100–120/min, 5–6 cm deep in adults, with full recoil and minimal interruptions. If trained and able, use 30 compressions to 2 breaths; otherwise continue compressions.
- Get an AED as soon as possible. Switch it on and follow the spoken/visual instructions. Expose the chest and apply pads as shown. Continue compressions during pad placement when another rescuer is available.
- Stand clear during rhythm analysis and shock delivery. Resume CPR immediately after a shock or a no-shock instruction. Continue until professional help takes over or the person shows clear signs of life.
Children
Follow the AED’s child-specific instructions. For infants and children below approximately 25 kg (roughly 8 years), activate paediatric mode/attenuation if available. If unavailable, use the standard mode rather than withholding the AED. For smaller children, use an anteroposterior pad position according to the device instructions, avoiding contact between pads.
Choosing and maintaining a public-access AED
Practical criteria include clear prompts, availability of child mode, ease of pad placement, self-tests, replacement-pad and battery availability, maintenance costs, outdoor temperature tolerance where relevant, accessibility 24/7, and registration in local AED location systems. Verify current certification, local service support and the manufacturer’s latest documentation before purchase.
Historical AED models (2015 article archive)
Philips HeartStart HS1 — historical photograph:
ZOLL AED Plus — historical photograph:
LIFEPAK CR Plus — historical photograph:
Technical specification images from the original article are preserved for archival reference, not for current clinical or purchasing decisions: Philips HS1 archive; ZOLL archive; LIFEPAK archive. The old dollar prices and 2010-guideline comparisons have been retired.
References: ERC Guidelines 2025; Adult BLS guidance; ERC 2025 paediatric life support; AHA 2025 adult BLS.
