ZOLL Aed Plus Administrator's Manual page 45

The difference in efficacy between the rectilinear biphasic and the monophasic shocks was greater in
patients with high transthoracic impedance (greater than 90 ohms). The first shock, first induction
efficacy of biphasic shocks was 100% versus 63% for monophasic shocks for patients with high
impedance (p=0.02, 95% confidence interval of the difference of -0.021% to 0.759% and 90%
confidence interval of the difference of 0.037% to 0.706%).
1st Shock Efficacy (High
Impedance Patients)
p-value
95% Confidence Interval
90% Confidence Interval
A single patient required a second biphasic shock at 150J to achieve 100% efficacy versus six patients
for whom monophasic shocks of up to 360J were required for 100% total defibrillation efficacy.
Conclusion: The data demonstrate the equivalent efficacy of low energy rectilinear biphasic shocks
compared to standard high energy monophasic shocks for transthoracic defibrillation for all patients
at the 95% confidence level. The data also demonstrate the superior efficacy of low energy rectilinear
biphasic shocks compared to standard high energy monophasic shocks in patients with high
transthoracic impedance at the 90% confidence level. There were no unsafe outcomes or adverse
events due to the use of the rectilinear biphasic waveform.
* Kerber, R., et. al., AHA Scientific Statement, Circulation, 1997; 95: 1677-1682:
"... the task force suggests that to demonstrate superiority of an alternative waveform over standard
waveforms, the upper boundary of the 90% confidence interval of the difference between standard and
alternative waveforms must be < 0% (i.e., alternative is greater than standard)."
ZOLL AED PLUS Administrator's Guide
Monophasic Biphasic
63% 100%
0.02
-0.021% to 0.759%
0.037% to 0.706%
35