For biphasic defibrillators, what energy dosing is recommended?

• A. Use the highest energy dose for all shocks without manufacturer's guidance
• B. If initial dose is not known, use the lowest energy for first shock
• C. Follow manufacturer's recommendations for the initial dose (usually between 120 and 200 J). Subsequent doses should be the same or higher; if unknown, use highest energy for first and all shocks
• D. Set energy to 360 J for biphasic

Answer: (C)

Biphasic defibrillators are most effective when you follow the device’s own dosing guidance instead of applying a one-size-fits-all energy. The best practice is to deliver the initial shock at the energy recommended by the manufacturer (normally in the range of 120–200 J). After the first shock, use the same energy for subsequent shocks or go higher if needed, because staying at or increasing the dose improves the chance of termination without underdosing. If you don’t know the initial dose, delivering the highest energy that the device allows within its recommended range for the first shock and continuing with the same or higher energy for subsequent shocks is the safer, more effective approach.

This differs from using the maximum possible energy for every shock, which isn’t advised without device guidance, and from using very low energy, which can fail to terminate the rhythm. Also, 360 J is typical of older monophasic devices and is not the standard for modern biphasic machines. Always refer to the specific defibrillator’s manual for exact values.