OHSU heads one of 24 community-based research centers in the Public Access Defibrillation Trial.
"This means that it will be important to make AEDs more available in busy public sites and encourage volunteers to be trained in CPR and the use of AEDs at these sites," said Mohamud Daya, M.D., OHSU's principal investigator in the study and associate professor of emergency medicine in the OHSU School of Medicine.
There have been numerous cases of AEDs used to save lives in airports and other public places. However this is the first randomized, controlled study to scientifically determine whether nonmedical volunteers can be trained to perform CPR and use AEDs effectively and if they can save more lives than volunteers who just perform CPR. In both circumstances, early activation of the local emergency medical services (EMS) was a part of the study design. AEDs in this study were only approved for use in adults with cardiac arrest.
Twice as many people who suffered cardiac arrest survived when the volunteer called 911, performed CPR and used an AED. However, this does not decrease the value of performing CPR when there is a rapid local EMS response because a significant number of people survived with this treatment alone.
The PAD trial trained approximately 20,000 volunteers who received two to four hours of initial training, and most were retrained one or more times during the study. A very important aspect of the study was the presence of volunteers willing to be trained and respond to a medical emergency at their work sites.
As part of the study Daya and his team coordinated the training of more than 1,500 community volunteers at 80 sites in the Portland metro area, Salem and Vancouver. Half of the sites received training in CPR, while the other half received training in AED use as well as training in CPR. At the end of the study, all sites were offered AEDs, donated by Philips Medical and training regarding their use.
Community participation and EMS support in Oregon and southwest Washington were key to the success of the study. "Our site volunteers and private and public EMS agencies made the study possible," said Daya.
Researchers used the PAD data to determine two other key findings. The study found that volunteers at CPR plus AED sites were more likely to perform CPR than the volunteers at sites without AEDs. This suggests that either people are more motivated to help others when they have the support of an AED or the voice commands given by the AED help guide the resuscitation. Researchers also found that trained volunteers could perform CPR and use an AED without hurting themselves or the patient.
"Knowing that AEDs can be used by properly trained volunteers in a variety of workplace environments is an important first step to introducing these devices in additional public settings," said Jerris Hedges, M.D., chairman of the Department of Emergency Medicine at the OHSU School of Medicine, co-principal investigator and one of the authors of the safety and CPR use sub-studies.
The two-year study was funded by the National Heart, Lung and Blood Institute, the American Heart Association, Cardiac Science/Survivalink, Medtronic Physio-Control, Philips Medical Systems, Laerdal and Guidant Corp.
There are more then 460,000 deaths from "out-of-hospital" cardiac arrests each year in the United States, about half of which occur suddenly. Most sudden cardiac arrests are caused when the heart stops beating effectively due to an abnormal heart rhythm. AEDs are able to quickly jump-start the heart back into a normal rhythm with an electrical shock. The time it takes from the cardiac arrest until the patient receives a rhythm-stabilizing electrical shock can be the difference between life and death. Nationally the survival rate from sudden cardiac arrest is 5 percent, and 20 percent of arrests occur in public locations. The NHLBI is currently funding a multi-center 7,000- patient study designed to evaluate whether providing the devices to families of heart attack patients will improve survival if a cardiac arrest occurs in that person's home. This is an important next step because 80 percent of cardiac arrests occur in the home.
Additional information from the PAD trial is still being analyzed, including long-term survival results, quality of life, mental function of survivors, and the cost of implementing each type of system (including the costs of identifying and training volunteers and placement of AEDs).
Other members of OHSU's PAD study team include: Jonathan Jui, M.D.; Terri Schmidt, M.D.; Lynn Wittwer, M.D. (Southwest Washington Medical Center); Maggie Gunnels, Ph.D.; Heather Brooks; Denise Griffith; and Chris Burke.
Mohamud Daya, M.D., principal investigator for OHSU PAD center, associate professor of emergency medicine in the OHSU School of Medicine, OHSU Hospital emergency physician and OHSU Heart Research Center scientist.
Jerris Hedges, M.D., co-principal investigator for OHSU PAD center, professor and chairman of the Department of Emergency Medicine at the OHSU School of Medicine, OHSU Hospital emergency physician and OHSU Heart Research Center scientist.