For sudden cardiac arrest victims, it’s impossible to tell beforehand how much energy will be required to convert a shockable rhythm to normal sinus rhythm. Each defibrillation attempt leads to an interruption in CPR which can have a negative influence on coronary perfusion pressure and myocardial blood flow, and is associated with poort neurologic outcomes.

While 200J is enough for many patients, it’s not enough for all. Increasing the dose of subsequent shocks above the first shock has been shown to be more effective for terminating VF than simply repeating a failed dose.

Moreover, no evidence exists that escalating to a higher level of energy is harmful to the heart. For difficult-to-defibrillate patients, LIFEPAK defibrillators give you the option to escalate energy to 360J—the most potent dose available—for the best chance of survival.