Performance of an automated external defibrillator in a moving ambulance vehicle☆
Received 11 September 2009; received in revised form 16 December 2009; accepted 23 December 2009. published online 01 February 2010.
Abstract
Aim of the study
The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport.
Methods
An ambulance was driven on paved (20–100km/h) and unpaved (10km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5–5m/s2) measured by the vibrometer in the previous phase of the investigation.
Results
The vibration intensity increased with increasing speeds on paved roads (1.98±0.44m/s2 at 100km/h). While driving on unpaved roads, it increased to 6.40±1.06m/s2. Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5–1m/s2, which corresponded to vibration intensities while driving on paved roads at 20–60km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms.
Conclusion
Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient.
ABSTRACT