Studies That Show The Efficiency Of The AEDs

AED Mandates and State Requirements - A series of studies have been made in the past concerning AEDs and EMTs intervention as well as manual defibrillation vs. automatic defibrillation. Here are some informative guidelines concerning different parts of the US where significant results and conclusions have been reached concerning the use of automated external defibrillators.

AED efficiency in Seattle

In Seattle , Washington a team led by Cummings in 1987 conducted a survey and tests were performed on 147 patients who suffered from ventricular fibrillation. Cummings and his team put side by side the intervention of emergency medical technicians (EMTs) and the automatic external defibrillators (AEDs) in order to evaluate their efficiency. He also evaluated the EMTs with manual defibrillators in his research. The results of his research showed that there are no noteworthy differences in the rates of admission - the figures being very close 54% for AED and 50% for manual defibrillators. Also the survival to discharge was 30% for AEDs and 23% for manual defibrillators and this is yet another insignificant difference.

In 1988, the use of an AED by non-medical personnel was brought into light. A 3.3 minute response time was required by this non-EMT. The paramedics needed 8.8 minutes to respond.

A group led by Weaver carried out another research. It was conducted on 504 patients with ventricular fibrillation. Weaver has also reached the conclusion of the previous studies carried out by Cummings. There were only slight differences in admission rates: 59% AED compared to 53% EMT. Anyway, the percentage of survival to discharge was superior for AED intervention in this study, 30% in comparison to the EMT 19%. This means that AEDs are more effective in saving lives than the intervention of medical technicians.

AED efficiency in Iowa

In the late 1980s a research performed by Stults and Brown evaluated the efficiency of EMTs using AEDs and EMTs using manual defibrillators. The research was carried out on 88 patients in VF. The results were similar to the Cummings studies. There are slightly notable differences in rates of admission - 29% for AED and 32% for manual. The rate of survival was 17% for AED and 13% for manual defibrillation.

AED efficiency in Minnesota

In this region other results have been reported. The studies carried out by Bachman and his team could not validate the results from Seattle and Iowa . The reason for this difference might be due to the fact that this research was made in the northern rural area. The figures in this study were as follows: survival rate to discharge 11% for paramedics, 5% for EMTs using manual defibrillators and an alarming 2.5% for interventions performed by basic EMTs. A distinct study was not carried out for VF. Also in this study, there were no survivors with sudden cardiac arrest that hadn't been assisted. These poor results may prove that in the rural areas of northern Minnesota , AEDs might not be very popular.

However, during another research performed in rural southeast Minnesota , other conclusions were reached. Vukov observed the EMTs intervention with manual and automatic defibrillators on 63 patients. He found that EMTs using automated external defibrillators had larger admission rates -30% compared to 12% - using manual defibrillators. The survival rates were way greater when employing the AEDs - 17% compared to the 4% rate of survival for EMTs that did not use AEDs.

AED efficiency in Tennessee

In a research carried out in 1988 by Gentile, the response of 23 patients in VF was observed. All 23 patients were administrated AEDs shocks. The intervention was performed by EMTs. The patients responded on average after 7.6 minutes.

The survival rate was 9%, and all the patients that survived were administrated shocks within the first 4 minutes after the sudden cardiac arrest.

AED efficiency in Detroit , Chicago , and New York

In Detroit an unofficial research was carried out on 595 patients, out of which only 20% were in VF. All the interventions were performed by basic EMTs using automatic external defibrillators. Only about 5% of these patients were brought into the hospital, but unfortunately the survival rate was 0%. This failure in saving none of the patients in due to the fact that the EMTs intervention appeared only after more than 10 minutes following the occurrence of the heart arrest, and once again this proves the fact that immediate intervention is essential in order to get results in first aid resuscitation.

Analogous figures have been published in Chicago and New York . Again, the survival rate was very low in both locations: 4% in Chicago while in New York was 5%. These unsatisfactory results are due to the fact that the EMTs responded on average only after 10-12 minutes following the incident.

Fore more resources on AEDs and other defibrillator information please see our other articles.