Here are a few Frequently Asked Questions about the ZOLL E Series®.

Why Biphasic?

Quite simply, biphasic is better for your patients!
High energy, monophasic shocks, are associated with more post-shock dysfunction and complications in patients. Biphasic waveforms lower the defibrillation threshold of myocardium, making it possible to successfully terminate VF with smaller amounts of energy than would be necessary with a monophasic defibrillator. While the exact mechanism is not fully understood, and many potential mechanisms have been put forward and one thing is clear, low-energy biphasic defibrillation, has been shown to reduce the severity of Post Resuscitation Myocardial Dysfunction (PRMD)*.
*Tang, W., Weil, M. H., & Sun, S. (2000). Low-energy biphasic waveform defibrillation reduces the severity of postresuscitation myocardial dysfunction. Crit Care Med, 28(Suppl. 11), N222.

Why use 200J? Isn’t 360J better?

Energy is not what defibrillates the heart, average current (or current density) is.
Energy is a combination of Voltage, Current and Time(duration) of shock.
Energy can be changed by varying voltage, current or time.

So what happens when we change these variables?

Voltage
(or potential) is limited by the capacitor in the defibrillator. Any defibrillator has a set amount of electrical energy that it can store for a shock. ZOLL defibrillators have the largest capacitors.

Time
The time of the shock can be varied, however, longer shock times are associated with post shock dysfunction also. Long shock times reduce the average current applied because the whole time the shock is applied, the current level decays.

Current
Current is limited by the patient’s resistance or impedance. Ohm’s Law states, the higher the patient’s resistance, the more voltage is required to pass the energy through at the same flow rate.

All current is not the same and it is not constantly delivered; It decays. The pattern of delivery (or waveform) counts. It is the rate of decay and length of shock that effects the amount of harmful high peak current required to generate the current density (or average current) required.

We need to deliver current in such a way that rapid decay of the current does not occur and therefore a high peak (or initial) current is not required. That is the basis of using a rectilinear waveform.

You can see that units that vary time to increase the number of Joules are really dealing in a false economy and that high energy does not equal high current.

How hard is it to change the screen mode?

Colour screens do not provide optimal viewing in all light conditions. The tri-mode screen is easily activated by holding down the contrast button for 3 seconds to toggle between screens.

How do I upgrade my parameters?

ZOLL units are often upgradable, however the unit will have to be sent back to ZOLL to have the relevant modules switched on internally. Once this is done, you are free to plug in the appropriate probe for measurement of the parameter.

How and what data is able to be transmitted?

The E series is able to transmit 12 lead data by Bluetooth to a PDA or laptop to emails and fax. The E Series is also capable of sending transmissions by fax by connecting to the unit.

The E series will transmit 12 lead waveforms in addition to numerical data and vital sign trend analysis.

Is the E Series available with invasive lines?

The E Series units cannot be upgraded to include invasive lines. The ZOLL M Series® CCT units are the only units that have invasive lines as an optional parameter.

I have an AC unit, but need to use DC power? Can it be done?

DC inverters are available to convert AC units for use with DC power sources. If you have a DC unit and wish to use it with AC power, a permanent conversion can be performed at ZOLL’s service centre.