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9.
Tec
hnical Specifications
Pediatric Waveform
Defibtech’s pediatric defibrillation is supported by publications by Tang et al.
2
and by Atkins et al.
3
As with the
adult Defibtech defibrillation waveform, the data provided by Defibtech demonstrates that the pediatric waveforms
from Philips and Defibtech are almost identical. The Tang animal study tested the defibrillation waveform used for
defibrillation success and safety on a pediatric model (swine). The Atkins clinical study was published in 2005 and
evaluated the same waveform in a post-market study.
The prospective, randomized animal study included piglets weighing 3.5 ± 0.5, 7 ± 1, 14 ± 1 and 25 ± 1 kg. The
study was divided into two (2) phases: In phase 1, 20 experiments were completed in four (4) groups of piglets
weighing 3.8, 7.5, 15 and 25 kg (average). After ventricular fibrillation (VF) was induced and maintained for 7 minutes,
a 50J biphasic truncated exponential shock was delivered (up to 3 shocks) by a manual defibrillator. In phase 2, nine
(9) experiments were completed on piglets weighing 3.7, 13.5 and 24.2 kg (average). The same VF duration was
treated with the AED waveform using a 150J biphasic waveform attenuated to deliver a 50J shock. All animals in
both groups were successfully defibrillated with return of spontaneous circulation. No differences were observed
in hemodynamic and myocardial measurements before cardiac arrest and after successful resuscitation. No
myocardial injury was observed during the autopsy in any of the animals. The study demonstrated that this 150J adult
defibrillation waveform attenuated to a 50J shock, successfully defibrillated and restored spontaneous circulation
without post shock dysfunction in this pediatric model.
Atkins et al. is a post-market observational study on pediatric patients intended to evaluate reported uses of pediatric
pads that reduced energy delivered by the Philips AEDs such that they could be used with pediatric patients. Pediatric
pads are designed for use on children 0 - 8 years old or up to 25 kg (55 lbs) that reduces the energy delivered by the
AED waveform from 150J (for adults) to 50J. Users of pediatric pads were asked to report to the original equipment
manufacturer for any use of the pads, even if no shock was delivered and to provide details about the event, caregiver
and patient. Electrocardiograms (ECGs) and information from the AED’s internal memory (when available) were
reviewed and confirmed by the principle investigator. All submitted information was also periodically reviewed by a
Data Monitoring and Safety Board. From May 2001 to November 2004, 30 cases were reported, and three (3) cases
were later excluded as being false reports and not included in the remaining analysis. Nineteen (19) cases were from
the US and the remaining eight (8) from outside the US. Ventricular fibrillation was reported in eight (8) cases, ages 4.5
months to 10 years. An average of 1.9 shocks were delivered. All patients had termination of VF and were admitted
to the hospital. Five (5) patients survived to hospital discharge. Until the attenuated pediatric pads for use with an
AED were first introduced in 2001, shock delivery to pediatric patients did not occur until a manual defibrillator arrived.
These reports indicate that the biphasic AED waveform performed appropriately since in all cases where VF was the
presenting rhythm, the VF was terminated via the AED, and five (5) survived to hospital discharge.
Defibtech DDU-2000 Series AED (continued)
DAC-U2510EN-BF rev H
56
