CPR and Automated External Defibrillators: Recognising Arrest, Acting and AED Safety

Direct answer. If someone is unresponsive, call the local emergency service immediately. If they are not breathing normally, start CPR and follow the dispatcher’s instructions. Use an available AED as soon as possible and follow its prompts. This adult-focused guide explains current emergency guidance and preparation; do not keep reading instead of making the emergency call.

Table of contents

• Evidence summary
• What it is
• How it works
• The evidence-based treatments
• Supplement and lifestyle evidence
• What works and what does not
• Risks and side effects
• Important interactions
• Who needs assessment
• Clinician-led use and follow-up
• Animal and in-vitro evidence
• Funding and source roles
• Frequently asked questions
• Sources and funding notes

Evidence summary

Confidence is high in the need for prompt emergency activation, CPR and appropriate AED use, supported by converging public guidance. Personal circumstances and local emergency instructions matter. This is an attributed care map, not a new comparative trial review. Confidence in a supplement replacing clinical care is insufficient in the eligible evidence assessed here. The full funding chains behind guideline drug and device trials have not been cleared.

What it is

Cardiopulmonary resuscitation, or CPR, provides emergency support when a person’s circulation has failed. An automated external defibrillator, or AED, analyses the rhythm and can deliver or instruct a shock when appropriate. Cardiac arrest and a heart attack are different events, although a heart attack can cause an arrest. NHLBI distinction; FDA device explanation.

This page focuses on community adult response, not hospital advanced life support, professional drug treatment or every special circumstance. Local emergency services and the device’s own prompts guide the real event. Country-specific telephone numbers in sources are not interchangeable; use the emergency number where you are.

How it works

Chest compressions support circulation while help is arriving. Defibrillation is a different action: a selected electrical shock treats certain dangerous rhythms. An AED checks whether a shock is indicated; a “no shock” message does not establish that the person is safe or that CPR should be abandoned. NHLBI basic care context.

The device system includes batteries and electrode pads, not just the case on the wall. FDA describes semi-automatic models that prompt a button press and fully automatic models that deliver the indicated shock. Follow the actual device rather than another model’s demonstration. FDA system distinctions.

The evidence-based treatments

RCUK’s public adult response guidance recommends calling immediately for an unresponsive person, then assessing breathing with dispatcher assistance. Gasping or panting is abnormal breathing. Start CPR when the person is unresponsive and not breathing normally; place the hands over the centre of the chest, allow recoil and minimise interruptions. RCUK public response guidance.

For adults, that guidance describes 100–120 compressions per minute and 5–6 cm depth. Trained rescuers can use 30 compressions followed by two rescue breaths; untrained rescuers use continuous chest compressions with dispatcher support. The newer UK guideline says to begin on a bed rather than delay by moving the person to the floor. Current adult recommendations.

Ask another available person to bring an AED while CPR continues. Open it, turn it on if needed, apply the pads as shown and follow the prompts. Do not postpone the emergency call to find equipment or read a product comparison. The relevant goal in this moment is to activate help and act, not to select the most expensive device. FDA public response context.

Supplement and lifestyle evidence

No supplement provides the circulation or electrical treatment needed during cardiac arrest. A claim about antioxidant activity, clot breakdown, heart strength or stress relief is not an alternative emergency response. This review has not established an independently screened oral rescue product, and supplies no emergency supplement dose.

After survival, follow-up addresses the cause, prescribed treatment, recovery and support. Activity needs the team’s clearance; an encouraging recovery story is not an individual exercise prescription. NHLBI selected follow-up context.

What works and what does not

Emergency recognition does not require a bystander to establish the precise cause. NHLBI’s symptom guidance says not to spend time finding a pulse; its separate older treatment page still mentions a pulse check. This guide follows the no-delay recognition approach, supported by the newer UK recommendations, rather than reproduce the conflicting wording.

Training can improve preparation, but a course certificate is not a prerequisite for following a dispatcher or using an available AED. No paid course, training app or manufacturer is endorsed here. A registry listing or institutional logo also does not by itself establish an independently measured improvement in survival.

For an organization, an AED’s location, access, serviceability and response plan are practical questions. A purchase receipt alone cannot show that people can find and operate it during an emergency. The device and its accessories need a named person responsible for the manufacturer’s actual maintenance schedule.

Risks and side effects

Protect the rescuer, the affected person and bystanders from hazards. During AED rhythm analysis or shock delivery, keep people clear as the prompts instruct. Resume CPR promptly when directed, including when no shock is advised. Adult AED safety guidance.

CPR can cause injury; current adult guidance still supports lay action for presumed arrest. That is not a guarantee of success. Follow the dispatcher and attend to scene hazards. Risk balance.

The event may be distressing for bystanders and families. After the emergency, ask for appropriate support. A resuscitation outcome should not be turned into a simple judgement of a bystander’s skill; many clinical and system factors affect recovery.

Important interactions

CPR and an AED are emergency actions, not a medicine combination to self-adjust. Tell emergency clinicians what is known about the person, but do not delay the call or compressions to assemble a complete medical or supplement history. Advanced treatment decisions belong to the responding professionals.

Pads, batteries and other accessories must be suitable for the actual AED. FDA’s US regulatory page separates device and accessory approvals and describes compatibility. A generic marketplace description cannot establish that two parts work together. Check equipment ahead of time with the responsible service or manufacturer. FDA device/accessory context.

Who needs assessment

The adult compression dimensions in this guide should not be copied onto infants or young children. Paediatric resuscitation differs in assessment, breathing support and technique. Follow the emergency dispatcher, the device’s paediatric instructions and appropriate child-specific training. Current paediatric guideline.

An unconscious person who is breathing normally needs a different assessment and response from presumed arrest. Do not use a remembered slogan to override what the dispatcher establishes about the person’s breathing and condition. Uncertainty is a reason to request emergency help, rather than withhold it.

Clinician-led use and follow-up

There is no CPR medicine or supplement dose here. Activate emergency help, use speakerphone where possible and follow the instructions given. If several people are present, identify who is calling, who is doing CPR and who can fetch the available AED; avoid assuming that somebody else has already called.

Prepare in advance by learning the local emergency number, finding accessible AED locations and practising response skills. If your workplace or community has a device, ask who checks pads, batteries, software or recalls and what happens outside opening hours. This guide does not specify a universal inspection interval or authorize a retailer’s maintenance package.

Animal and in-vitro evidence

Laboratory effects on heart cells cannot establish that an oral product reverses cardiac arrest. Device engineering or a manikin practice result is also different from real-patient survival, which depends on the emergency system, timing and clinical circumstances. This guide has not audited the full financial chain of comparative AED or training-outcome studies, and reports no vendor-specific survival advantage.

Funding and source roles

Commercial interests include AEDs, disposable pads and batteries, maintenance services, training manuals, courses and software. RCUK explicitly earns income from courses and related products; FDA receives regulated-industry user fees. These roles are disclosed without treating an institutional label as complete independence. The clinical response is attributed to guidelines and public originals; manufacturer outcomes and paid-provider superiority claims are excluded from the independent verdict.

This guide concerns emergency response; particular devices and training products have their own owners and manufacturing origins. Providers, pharmaceutical companies, device manufacturers and supplement sellers can receive revenue from different care choices. That is an incentive analysis, not an allegation of improper care. This source set is concentrated in the United States and United Kingdom. Retail manufacturing origin, batch quality and the complete financial chain of original treatment trials were not established.

Funding tier measures proximity to the subject; the credibility grade evaluates transparency and accuracy incentives. Provisional classifications are not a declaration that every conflict has been excluded. Public financial support for an educational page does not turn commercially supported underlying trials into independent efficacy evidence.

Frequently asked questions

Must I find a pulse first?
A lay rescuer should not delay emergency action to search for a pulse.

Can an untrained person use an AED?
Yes. Follow its prompts and emergency-dispatcher instructions; preparation and training can help.

Will the device always shock?
No. It analyses the rhythm and advises a shock only when appropriate.

Is this a complete child-resuscitation manual?
No. Child-specific techniques and circumstances differ; follow emergency instructions.

Can I wait for an app or supplement?
No. Neither replaces calling for help and acting during presumed cardiac arrest.

Sources and funding notes

• RCUK original public CPR response page — Emergency recognition, dispatcher help and adult response; paid book/training claims excluded.
• RCUK adult basic life support, October 2025 — Current attributed adult emergency framework.
• NHLBI cardiac arrest symptoms, May 2022 — Recognition and no lay pulse-search delay.
• NHLBI cardiac arrest treatment, May 2022 — Basic CPR/AED and subsequent hospital-care context; dated protocols excluded.
• FDA original AED and accessory information — Device role, US approval and maintenance context.
• FDA original public AED information — Voice prompts, operator assistance and regulatory scope.
• RCUK paediatric life support, October 2025 — Child/adult scope distinction; not a full child protocol.
• RCUK original 2025 guidelines process — Methods and conflict-management process, not full author clearance.
• NHLBI life after arrest, May 2022 — Selected follow-up and emotional-support context.
• RCUK own funding and governance page — Paid courses, royalties, donations and ownership route.
• RCUK own current corporate-partnership page — Named partnerships and funding solicitation.
• RCUK original annual report 2023/24 — Historical income routes; not current guideline allocation.
• UK Charity Commission RCUK register — 2025 accounts indexed; direct latest PDF blocked.
• FDA actual FY2026 operating plan — Appropriations and industry fees.
• NHLBI budget and legislative information — institutional public funding and gift-fund context; not a page-level donor audit.

NHLBI clinical originals, FDA device pages and its actual FY2026 financial plan, the 2025 RCUK clinical/methods pages and its current funding/partnership pages were opened. The historical 2024 RCUK annual report was retrieved; 2025 accounts were indexed in the charity register, but full direct latest-PDF access was blocked. No original vendor or training-outcome trial was financially cleared. Education, financial self-disclosure and therapeutic outcome evidence are separate roles. No manufacturer-supported outcome study establishes the independent verdict in this guide. A complete systematic review, author-by-author financial audit and current local prescribing comparison were not completed. These limitations constrain the conclusion; they do not prove that clinical treatment is ineffective.

Last reviewed: October 4, 2026. Educational information; during a real emergency, call the local emergency service immediately and follow dispatcher instructions.