What is the Lifepak defibrillation energy sequence for three shocks?

• A. 200J, 300J, 360J
• B. 360J, 300J, 200J
• C. 300J, 200J, 360J
• D. 200J, 360J, 300J

Answer: (A)

In a LifePak defibrillator, the three-shock sequence is designed to escalate energy to maximize the chance of terminating a shockable rhythm while keeping initial energy lower to reduce myocardial injury. The first shock is delivered at 200 joules, if needed the second shock at 300 joules, and if still unsuccessful, the third shock at 360 joules. This rising-energy approach reflects how biphasic shocks work: they’re effective at lower energies, but increasing the energy if the first attempt doesn’t succeed improves the odds of defibrillation without sticking at a single high energy from the start. Starting with 360 joules would expose the heart to more energy than necessary initially, and subsequent sequences that don’t ascend in energy aren’t aligned with LifePak programming and ACLS guidelines.