During CPR with an AED, if you are the sole rescuer and the AED indicates a shock, how many shocks should you deliver before resuming CPR?

• A. 2
• B. 3
• C. 1
• D. 0

Answer: (C)

When you’re the sole rescuer using an AED during CPR, and the AED directs a shock, you deliver a single shock and then immediately resume CPR. Giving just one shock minimizes the interruption to chest compressions, which are essential for maintaining blood flow during cardiac arrest. After delivering that one shock, start rescuers’ high-quality CPR right away (continue with chest compressions at a rate of about 100–120 per minute and a depth of about 2 inches/5 cm for adults) and let the AED reanalyze after the next complete CPR cycle (roughly every 2 minutes). Delivering additional shocks without resuming compressions would unnecessarily delay perfusion; thus a single shock followed by immediate resumption of CPR is the best approach.