Final answer:
After an AED indicates no shock is advised, you should perform CPR. AEDs are equipped to perform a diagnosis and deliver necessary shocks, while providing guidance to users. CPR is often recommended before AED use in emergency situations.
Step-by-step explanation:
When an AED prompts that no shock is advised, the next crucial step is typically to perform cardiopulmonary resuscitation (CPR). Very large currents from defibrillation can cause the heart and diaphragm to contract, halting the heart and breathing, but they often return to normal post-shock. On the other hand, ventricular fibrillation, an arrhythmic condition caused by smaller currents, requires a shock for potential recovery. AEDs are automated to diagnose the heart's condition and deliver appropriate shocks, while prompting the user through the process. It is also common for CPR to be administered before using an AED to improve the chances of survival. These devices are designed to be used by laypersons and can be found in many public places.