Systematic review

The efficacy of Automated external defibrillators programs in the

community

Class- 12 1 st year 2006/2007

Ana Vigário, Daniela Rodrigues, Diana Marques, Fátima Marisa Queirós, Inês Garrido, Leonor Matos, Liliana Tavares

Introduction to Medicine 6 of March of 2007 Porto University Medical school

Class- 12 1st year 2006/2007

• Introduction: • Definition of sudden cardiac death (SCD)

• Epidemiology of SCD in the community

• Prevention of SCD in the community

• Automated external defibrillator programs

• Objective of the study

• Methods and Material• Query used in the systematic review

• Inclusion and exclusion criterias

• Flow Chart of the methods used

• Presentation of all articles on an excel´s table

• Results• SPSS table

• Website map

• Work plannification

Contents

Class- 12 1st year 2006/2007

Sudden Cardiac Death Definition: The expression “sudden death” has been used for several centuries.

Key points in the definition of sudden death: 1. non traumatic event

2. unexpected and instant event

• Natural cause death, secondary to cardiac causes, with sudden lost of conscience, until 1 hour after the onset of the acute symptoms (1).

– The previous existence of cardiac disease can be known

– The timing and death mode are unexpected.

Introduction

1. Priori S, et all. Task Force on sudden cardiac death. Europace; 2002, 4: 3-18

Class- 12 1st year 2006/2007

• Is the most frequent cause of death in the adult population of industrialized countries (2)

• The incidence of out-of-hospital sudden death varies with age, gender and the presence of cardiovascular diseases (3)

• The majority of deaths due to SCD occur in men.(4)• The number of SCD cases occuring at home is much

higher then the number of SCD cases occuring in streets or in public places ( e.g.: 80% of all SCD cases occur at home and 15% occur in streets or in public places (4))

Epidemiology of SCD (I)

2. Cobb L et al. Changing incidence of out-of-hospital ventricular fibrillation, 1980-2000. JAMA 2002; 288: 3008-13

3. DeVreede-Swagemakers et al. Out-of-hospital cardiac arrest in the 1990’: a population based study in the Maastricht area on incedence, characteristics and survival. JACC 1997; 30: 1500-5

4. American Heart Associaion. Heart disease and Stroke statístics – 2005 Update. Dallas, Texas: AHA 2004

Class- 12 1st year 2006/2007

• Most SCD victims present ventricular fibrillation as the main cause of the event (4) and as their first heart rhythm (5) .

• It is likely that many more victims have VF or rapid ventricular

tachycardia (VT) at the time of collapse but, by the time the first

ECG is recorded, their rhythm has deteriorated to asystole (6)

Epidemiology of SCD (II)

5. Rea TD et all. Incidence of SEM-treated out-of-hospital cardiac arrest in the USA. Resuscitation 2004; 63: 17-24

6. Waalewijn RA et all. Prevention of deterioration of ventricular fibrillation by basic life support during out-of-hospital cardiac arrest. Resuscitation 2002; 54: 31-6

Class- 12 1st year 2006/2007

Prevention of SCD in the community• SCD that occurs in apparent healthy individuals cannot be prevented. • The rate of overall survival in out-of-hospital SCD cases is very low (7)• This survival rate does not increase with the existence of advance life

support emergency systems.(8) • The individual survival can be dependent on automated external

defibrillators, however, the rapid availability after onset of the event is crucial. (9)

7. The public access defibrillation trial investigators. Public-access defibrillation and survival after out-of-hospital cardiac arrest. NEJM 2004; 351: 637-468. Stiell I et al. Advanced cardiac life support in out-of-hospital cardiac arrest. EJM 2004; 351: 647-569. European Ressucitation Council. Part 2: Adult basic life support and use of automated external defibrillators. Resuscitation 2005; 67: s7-23

Class- 12 1st year 2006/2007

• The early defibrillation has demonstrated to be critical in the survival improvement of SCD (10)

• Many victims of SCA can survive if bystanders act immediately while VF is still present (11)

• CPR plus defibrillation within 3-5 minutes of collapse can produce survival rates as high as 49-75% (12)

Prevention of SCD in the community

10. Marenco J et al. Improving survival from sudden cardiac arrest: the role of the automated external defibrillator. JAMA 2001; 285: 1193-20011. Larsen MP et al. Predicting survival from out-of-hospital cardiac arrest: a graphic model. Ann Emerg Med 1993; 22:1652-812. White R et al. Evolution of a community-wide defibrillation programme experience over 13 years using police/fire personnel and paramedics as responders. Resuscitation, 2005; 65(3): 279-83.

Class- 12 1st year 2006/2007

What is an automated external defibrillator?What is an automated external defibrillator?

• It’s a small device, consisted of a computerized part that delivers

shock to victims of VF cardiac arrest. The device is attached to the

victim by adhesive pads or electrodes, which records and analyzes

the victims electrocardiogram rhythm, informs the rescuer if a shock

is needed and provides voice and audio prompts to guide the

rescuer through all steps of AED use. (13)

Automated external defibrillator

13. A.W. Diack, W.S. Wellborn, R.G. Rullman et al., An automatic cardiac resuscitator for emergency treatment of cardiac arrest. Med Instrum 13 (1979), pp. 78–81. Abstract-EMBASE | Abstract-INSPEC   | Order Document | Abstract + References in Scopus | Cited By in Scopus

Class- 12 1st year 2006/2007

• Over the past two decades, automatic external defibrillators (AED) have been developed and improved to allow single rescuers to defibrillate victims of cardiac arrest rapidly.(14)

• The expansion of the role of defibrillation to both minimally trained first-responders (police officers, firefighters, security guards, flight attendants) and to trained laypersons who witness an arrest.(15)

• The placement of automated external defibrillators (AEDs) in such areas as airports, convention centers, sporting arenas, casinos, shopping malls, and large office buildings. (16)

• An organized and practiced response, with rescuers trained and equipped to recognize emergencies, activate the emergency medical services system, provide CPR, and provide defibrillation in situations where quickness is determinant. (17)

Automated external defibrillator programs

14 Becker S et al. Minimal instructions improve the performance of layperson in the use of semiautomatic and automatic external defibrillators. Critical Care 2005; 9: 110-1615. Davies C et al. A national program for on-site defibrillation by lay peolple is selected high risk areas: inicial results. Heart 2005; 91: 1299-30216. Zipes DP, Wellens HJ. Sudden cardiac death. Circulation. 1998;98:2334-2351

17. Lim S et al. Results of the first five years of the prehospital automatic external defibrillation project in Singapore in the “Utstein style”. Resuscitation, 2005; 64: 49-57 2.

Class- 12 1st year 2006/2007

Improve outcome from sudden Improve outcome from sudden deathdeath ??

The efficacy is not overall stablishedThe efficacy is not overall stablished

Lay rescuer AED programsLay rescuer AED programs may:

• Provide an early recognition and correction of these dysrhythmias by lay rescuers;

• Increase the number of people who receive bystander cardiopulmonary resuscitation (CPR);

•Reduce time to defibrillation.(18)

18. Joseph V. Automatic external defibrillators: lessons from the past, present and future . Resuscitation 1999; 41: 219

Class- 12 1st year 2006/2007

The main objective of this study is to evaluate whether

the utilization of the AED in the community in AED

programs reduces overall mortality of SCD and

increases quality of life of the survivors.

Objective

Class- 12 1st year 2006/2007

Methods

• Systematic review of published articles

• Bibliographic research in medical databases: • PubMed’s

• Searching criteria: • from the earliest achievable date until March 2007. • Terms used: automated external defibrillator, public access

defibrillation, sudden cardiac arrest, out-of-hospital cardiac arrest, ventricular fibrillation or tachycardia

• Manual review of the relative articles of the articles included in the systematic review and manual review of cited references

Class- 12 1st year 2006/2007

Query used to search PubMed:

("automated external defibrillator" OR "automate external defibrillator programs" OR "public access defibrillation" OR "out-of-hospital defibrillation" )

AND

("Death, Sudden, Cardiac"[MeSH] OR "sudden cardiac arrest" OR "sudden cardiac death" OR "out-of-hospital cardiac arrest" OR "Ventricular Fibrillation"[MeSH] OR "ventricular fibrillation" OR "Tachycardia, Ventricular"[MeSH]OR "ventricular tachycardia" OR " emergency life support" OR " cardiopulmunary resuscitation" OR " cardiac arrest" OR " basic life support")

Methods

Class- 12 1st year 2006/2007

Inclusion Criteria:

Initial tracing (inclusion): performed by one group, composed of three reviewers, according to the inclusion criteria mentioned below:

1- Being presented in English, French, Portuguese or Spanish;

2- Using an Automated External Defibrillation;

3 - Aplicated to humans;

4- Studies made only out-of-hospital;

5- Not Being a sistematic review;

6- Lack of information available.

Methods

Class- 12 1st year 2006/2007

Exclusion criteria: • performed by three groups, composed of two reviewers.

• Selection was made by consense of the two reviewers of each group:

• Exclusion criteria: 1 - Not being based on the systematic review’s theme – concerning studies

published about AED programs in the community.

2 – Articles not having information about survival rates at hospital discharge after implementation of AED programs or data that made possible it’s calculation.

3 – Studies with less than 50 patients or programs with a duration of less than 6 months

4 – Studies about AED community programs, where AED’s were used only by medical professionals.

Methods

•Methods Flowchart

•Excel’s table

Class- 12 1st year 2006/2007

ResultsThe articles resulted from the query were analysed by all members

of the group. After applying the inclusion and exclusion criterias, a total of 16 articles were selected at the end. A detailed analysis of those final article was made and it is presented on a SPSS table.

The main points of the final data are:

•The 16 included articles were analyzed in a SPSS table and the data form each article was put together and re-analyzed according to their category, which we named studies.

• In 5 studies it was possible to calculate the survival rate with the use of AED. 50% was the rate for 4 of this studies.

•In 7 studies we calculate the rate of survival for patients whom had FV/TV and the AED was used. In 3 of those studies the rate was higher then 50%.

•The rate of mortality was calculated in 8 studies for patients whom the AED was used. In 3 of these studies the rate was lower then 50%.

Class- 12 1st year 2006/2007

•In 10 studies we calculated the rate of mortality for patients whom had FV/TV and the AED was used. In 5 of those studies the rate was lower then 50%.

•One of the articles compares the survival rate before and after the implementation of the AED. The analysis of this article was made in two studies for a better analysis and understanding of the data. According to this article the rate of survival does not improve with the implementation of the AED in out-of-hospital. The rate of survival decreases from 17.11% to 9.78% after the implementation of the AED. The data obtained in this study was statistically significant for our systematic review.

•Another article was also a particular case. It compares the use of the AED´s exclusively by paramedics and the use of the device also by police officers. The time of fibrillation decreased to 26% and the probability of survival increases 10 times. So it can be conclude that the use of AED by police officers can reduce the time of fibrillation, which consequently increases the rate of ROSC (return of spontaneous circulation).

Class- 12 1st year 2006/2007

• Website map

• Work plannification

•SPSS table