26
Slides courtesy of Mark Estes, MD Role of AED’s
Slides courtesy of Mark Estes, MD
Role of AED’s
www.HRSonline.org
1940 Concept Developed
1977 Implantable cardioverter defibrillator
1979 AED developed
2000 American Airlines Trial
1960 Bedside defibrillators
1967 Portable defibrillators
2002 Casino Trial2003 OHare Trial
2005 PAD Trial2004 Miami Trial
AED Milestones
www.HRSonline.org
Approaches to Treatment of Sudden Cardiac Arrest
Out-of-hospital sudden cardiac arrest (SCA) accounts for over 300,000 deaths annually in the U.S.
In 1991, The American Heart Association (AHA) introduced the 4-step “Chain of Survival”Early activation of emergency response system
CPR
Early defibrillation
Advanced Life Support Measures
Operation Heartbeat
www.HRSonline.org
Time in VF in minutes
SCD From VF
www.HRSonline.org
0
10
20
30
40
50
First RespondersFirst Responders
Mossesso WeaveWeaverr
Weaver
% S
urv
ival
Survival RatesFirst responders (AED) vs EMT
EMTEMT
WhiteWhite
P <0.01P <0.001
P<0.02
NS
www.HRSonline.org
AEDs Improve Survival
White RD. Ann Emer Med. 96;28:480-485. Cobb LA. Circ. 92;85:I98-102. Smith SC. Circ. 97;13:1321-1324.
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
National Average Boston,MA Seattle,WA Rochester,MN
www.HRSonline.org
Boston-Survival from SCA
Comparison of AED Training and Survival of Utstein Cardiac Arrest in Boston, 1993-1999
245
686
1393 14821719
3272
2369
14%
18%
21%
26%
20.5%
25%
34%
1993 1994 1995 1996 1997 1998 1999
Year
AED Certified
UtsteinSurvival Rate(%)
USA Today July 30, 2003
www.HRSonline.org
Role of the AED in Preventing SCDLas Vegas Casinos
Valenzuela TD NEJM 2003
www.HRSonline.org
Evidence Based Medicine AEDs
Report Design % Survival STD Rx
AED P Value Benefit
White OBS 42 46 <.02 √
Weaver OBS 18 38 <.001 √
Smith OBS 22 36 <.001 √
Mossenco OBS 8 26 <.01 √
Weaver OBS 28 30 NS X
Page OBS 44 √
Myerburg RCT 11 28 <0.05 √
Valenzuela OBS 44 √
Caffrey OBS 48 √
Capucci RCT 21 44 <.01 √
PAD RCT 15* 29* <.04 √
HAT RCT 6.5** 6.4** 0.77 X
*# of Survivors **total mortality
www.HRSonline.org
To evaluate whether adding AEDs to a CPR based, community volunteer response system increases survival in victims of out-of-hospital cardiac arrest
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
The Public Access Defibrillation Trial: Main Study Objective
www.HRSonline.org
PAD Trial Design
High Risk Community Units
Call 911CPR
Call 911CPRAED
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
Prospective, randomized, controlled clinical trialCompared two lay volunteer-based OOH-CA response systems
www.HRSonline.org
PAD Trial
• 993 Community sites selected based on a 50% probability of OOH-CA in 15 months, EMS response < 15 minutes and no existing AED program
• 24 US and Canadian cities
• 20,000 lay volunteers received standard training
• 1600 AEDs placed
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Trial Location of Cardiac Arrest
0
10
20
30
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Location of Cardiac Arrest
Non-residential Non-residential 85 % 85 %
Residential Residential 15%
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Trial-292 Resuscitation attempts
Survivors44
CPR and 911Survivors
15
CPR, 911, AEDSurvivors
29
Residental 1
Non-residental 14
Residental 1
Non-residental 28
P=0.74
P=0.042
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Trial Results
•Volunteer rescuers responded twice as frequently at CPR & AED sites (23%) as at CPR sites(11%) alone
•No inappropriate shocks
•No failure to shock
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Trial Results
•292 resuscitation attemptsSurvivors: 15-CPR
29-CPR &AED (p=0.04)
•Use of public access defibrillators doubles survival from cardiac arrest
•Results better in public versus residential locations (75% of cardiac arrests are at residential locations)
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
PAD Trial Conclusions
•Trained laypersons can use AEDs safely to provide early defibrillation
•Survival doubles when AEDs are added to CPR trained volunteer response systems
•The survival rate in residential facilities is very low
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
AEDs Available for Home Use With Rx
Estes NAM Circulation 2005
www.HRSonline.org
PAD Trial-Implications
•The PAD Study strengthens the concept that AEDs should be widely available in public locations
•Survival was dependent on the presence of the AED, trained lay persons, and the presence of an emergency response plan
PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645
www.HRSonline.org
Bethesda 36 Guidelines: AEDs
Myerberg R, Estes NAM, Fontaine J, Link, M Zipes Bethesda #36 Conference AEDs, JACC 2005
www.HRSonline.org
AED-Public Policy, Legislation and Legal Liability
State and Federal Polices
Legal Protection for Owners, Users,Medical Directors
Court OpinionsAs evidence-based medicine has defined the
clinical benefits of AED use, public policy, laws, funding programs, and court decisions have served the societal interest of promoting use of AEDs by minimizing legal liability.
England, H Weinberg P, Estes N JAMA 2006
www.HRSonline.org
AED Initiatives
www.HRSonline.org
•Good Samaritan legislation in all states
•Public Access to Defibrillation Programs
•AED in Schools-NY, PA, WI, MA
•Neigborhood AEDs
•AEDs should be available in all schools and public locations where the emergency medical response time for a cardiac arrest is 5 minutes or greater
•AEDs should be used in cardiac arrest for all children older than 2 years of age
AED Initiatives
www.HRSonline.org
Future research
•Home AED Trial (HAT)
•Prospective randomized trial of high risk patients post MI
•Randomized to AED &CPR Training versus CPR training in high risk post MI patients
www.HRSonline.org
Role of the AED in Preventing SCA-The US Experience
•Evidence based medicine demonstrates decreased time to definitive therapy with defibrillation with AED use
•This results in improved survival in victims of SCA
•The benefit of AEDs is mainly in non-residential settings
•Organizational, institutional, state and federal policies, legislation, a laws serve to promote the widespread use of AED
•Further research is need to define optimal strategies for use of AEDs to improve outcomes from SCD
