External Biphasic Defibrillator Problems Being Reviewed by FDA

The FDA has launched an investigation into potential problems with external biphasic defibrillators after receiving a number of reports that some appear to be too low powered.

An initial communication was issued by the FDA on November 5 to health care professionals, as well as the American Heart Association and others, seeking information on whether low-powered defibrillators are effective in saving the lives of people undergoing a cardiac event.

The agency indicates that at least 14 reports have been received since 2006 of instances where biphasic defibrillators with an energy level of 200 Joules or less were ineffective and the patient’s life was saved by switching to higher-powered defibrillators.

In its communication, the FDA said that it is seeking input from health care professionals on how to interpret the reports. There has been only one scientific study on how the power levels of defibrillators factor into the success rate, but that study found no detectable differences in clinical outcomes. However, the study did find that escalating the energy levels during the course of the procedure resulted in a higher survival rate for patients.

The FDA is asking health care professionals to report any situation where a patient required multiple shocks from multiple defibrillators to its MedWatch adverse events reporting program. Specifically, the agency would like health care professionals to include information on:

• Energy levels
• Waveform
• Acute vs. chronic cardiac rhythms
• Drug therapy
• Oxygenation
• Paddles vs. pads
• Delay in therapy
• Make and model of devices
• Time from collapse to shock.

“FDA is seeking additional information in order to interpret the significance of these events, and to determine whether FDA activities are advised,” the communication states. “So far, our analysis of the 14 cases does not suggest the need for any change to current clinical practice.”

The FDA said that the feedback it receives will help determine whether there is any need for regulatory action or guidance on defibrillator power levels.