Automated External Defibrillator (AED) Use and Defibrillation
The sequence
Turn the AED on and follow its prompts: bare and dry the chest, apply pads to the upper right chest and the left lateral chest (or anterior-posterior), let the device analyze, ensure no one is touching the patient, deliver the shock, and immediately resume compressions without checking a pulse or rhythm. Continue 2-minute cycles of CPR, letting the AED reanalyze at each pause. Defibrillation is most effective early, so do not interrupt compressions longer than necessary; a second rescuer should apply pads while the first keeps compressing.
Special situations
Move the patient out of standing water and dry the chest. Remove transdermal medication patches from the pad sites. Avoid placing a pad directly over an implanted pacemaker or ICD generator. For a very hairy chest, shave or apply and remove a set of pads, then use a fresh set. Pediatric attenuated pads are preferred for children under 8 years or under about 25 kg when available, but a standard adult AED should be used rather than delaying a shock.
Traps
Frequent distractor answers: "check the rhythm/pulse before resuming compressions after a shock," "shock asystole to be safe," "wait for the AED to charge before stopping compressions," or "do not use an AED in pregnancy" (it is safe). Another trap is failing to clear the patient - always announce and visually confirm that no one is in contact.
Rule of thumb
Shock, then compressions immediately - the post-shock pause is the deadliest gap in the cycle. The only reliable rule is: hands on the chest until the moment of the shock and back on within seconds after it.