An Automated External Defibrillator is a portable electronic device designed to diagnose life-threatening cardiac arrhythmias of ventricular fibrillation and pulseless ventricular tachycardia. It is built to be used by both laypersons and healthcare professionals during sudden cardiac arrest emergencies. The device analyzes the heart's electrical rhythm through chest electrodes and delivers an electrical shock to restore a normal rhythm if necessary. Time is critical during cardiac arrest; every minute the heart remains in a shockable rhythm decreases the chance of survival by about ten percent.
An AED must only be deployed when a patient exhibits specific clinical criteria indicating sudden cardiac arrest.
AEDs are programmed to identify two specific heart rhythms that respond to defibrillation:
Operating an AED follows a logical sequence. First, turn the power on, which usually activates voice prompts. Expose the patient's bare chest, wiping away moisture or excessive chest hair if necessary. Peel the backing off the adhesive pads and apply them firmly to the skin.
An AED does not replace cardiopulmonary resuscitation; it complements it. Chest compressions circulate oxygenated blood to the brain and heart, while the AED corrects lethal rhythms. When the AED instructs you to clear the patient for analysis or shock delivery, compressions must stop. Immediately after a shock is delivered, or if the device advises no shock, resume chest compressions without delay. Minimize interruptions in chest compressions to maintain coronary perfusion pressure.
Certain environmental and physical conditions require adjustments during AED deployment. Water on the chest or conductive surfaces can misdirect the electrical current, so dry the chest thoroughly before pad placement and move the patient out of puddles. Avoid placing pads directly over implanted pacemakers or medication patches; instead, offset the pad at least an inch away from the device or patch.
Once spontaneous circulation returns, the patient requires continuous monitoring of airway, breathing, and circulation. If the patient remains unconscious, place them in the recovery position unless spinal injury is suspected. Prepare for a structured clinical handover to the incoming emergency team, detailing the duration of arrest, number of shocks delivered, and response to interventions.
Reliability depends on routine equipment checks. AEDs feature self-test functions that flash a status indicator light or emit an audible chirp if a fault is detected. Nursing staff must regularly inspect battery expiration dates, pad integrity, and ensure backup supplies like razors and spare batteries are present. Documenting these checks ensures regulatory compliance and patient safety.