What is the initial defibrillation energy for a monophasic defibrillator, and how does it compare to biphasic devices?

What is the initial defibrillation energy for a monophasic defibrillator, and how does it compare to biphasic devices?

• A. Monophasic: 120-200 J; Biphasic devices deliver 360 J initial.
• B. Monophasic: 360 J; Biphasic devices deliver 120-200 J initially according to device specs.
• C. Monophasic: 200 J; biphasic 100 J.
• D. Monophasic: 500 J; biphasic 300 J.

Answer: (B)

Defibrillation energy depends on the waveform used. A monophasic defibrillator delivers a single current in one direction and generally requires a higher energy to reliably terminate ventricular fibrillation, with about 360 joules as a typical initial shock. Biphasic devices deliver current in two phases with a reversal, which makes them more efficient at defibrillation, so their initial energy is lower—commonly around 120 to 200 joules, depending on the device. Because of this efficiency, a biphasic device often achieves success with the lower initial energy, while monophasic systems rely on the higher 360 J initial shock. Device-specific guidelines may vary, and subsequent shocks are guided by the device’s recommended protocol.

Defibrillation energy depends on the waveform used. A monophasic defibrillator delivers a single current in one direction and generally requires a higher energy to reliably terminate ventricular fibrillation, with about 360 joules as a typical initial shock. Biphasic devices deliver current in two phases with a reversal, which makes them more efficient at defibrillation, so their initial energy is lower—commonly around 120 to 200 joules, depending on the device. Because of this efficiency, a biphasic device often achieves success with the lower initial energy, while monophasic systems rely on the higher 360 J initial shock. Device-specific guidelines may vary, and subsequent shocks are guided by the device’s recommended protocol.