Semi-automatic External Defibrillators Research Articles

Out of hospital cardiac arrests—the experience of one hospital in Singapore

In Singapore, all public emergency ambulances are equipped with semi-automatic external defibrillators and the crew is trained in their use. This is the first paper from Singapore reporting the survival rate in patients presenting to an urban public hospital with acute coronary syndrome (ACS) who developed out-of-hospital cardiac arrest (OHCA). All consecutive patients who presented to the ED of a public hospital with OHCA or ACS were surveyed from 1 April 1999 to 30 September 1999. There were 392 patients among whom 115 (28.5%) had OHCA. There was no significant difference in age and gender distribution between the OHCA and non-OHCA patients. More than 2/3 of the OHCA patients had no report of chest pain or breathlessness before they collapsed. Forty five (39.1%) of the 115 OHCA patients were noted to have initial rhythms of ventricular tachycardia (VT) or ventricular fibrillation (VF) and received pre-hospital defibrillation. The mean time from collapse to first DC shock was 12.07±7.2 min. Twenty (17.4%) of the OHCA patients had return of spontaneous circulation after resuscitation in the ED. Four patients (3.5%), all with an initial rhythm of VF were discharged alive from the hospital. Much remains to be done to reduce the time interval to first DC shock for the OHCA group.

Teaching colleagues and the general public about automatic external defibrillators.

Every year 250,000 or more people with cardiovascular disease die within an hour of symptom onset and before they arrive at a hospital. With appropriate early defibrillation and follow-up treatment many people who might have died can now live. Nurses are key health care professionals for using automatic external defibrillators in hospitals and for teaching other first responders--inside and outside hospitals--how to use automatic external defibrillators. Features of automatic and semiautomatic external defibrillators are reviewed as well as ethical considerations for the use of automatic external defibrillators.

Anomalous ECG downloads from semi-automatic external defibrillators

The coincidental print-out by two different Laerdal® systems (subsequently called `system A' and `system B') of the same medical control module (MCM) for a Laerdal® Heartstart 2000 semi-automatic external defibrillator (SAED) led to the discovery of three deficiencies in the information storage and printing processes. First, we noted that the impedance reported via system A was consistently higher. Second, we found the attachment of `mysterious' ECG samples in the reports from system B, but not from system A. A third problem was the unpredictable (in)ability of system B to print out the information from the MCMs. Further investigations with help from the company suggested that the above-mentioned problems were caused by incompatibilities between the software in the different parts of equipment used (i.e. SAED devices, MCMs, printing systems and a computer program to store the information in a database). These observations demonstrate the need for strict medical supervision on all aspects of a SAED project, and for feed-back from clinicians to manufacturers.

9. Software safety and semi-automatic external defibrillators

9. Software safety and semi-automatic external defibrillators

9. Software safety and semi-automatic external defibrillators

9. Software safety and semi-automatic external defibrillators

An airline cardiac arrest program.

As many as 1000 lives are lost annually from cardiac arrest in commercial aircraft. Ventricular fibrillation (VF), the most common mechanism, can be treated effectively only with prompt defibrillation, whereas the current policy of most airlines is to continue cardiopulmonary resuscitation pending aircraft diversion. The objective of this study was to assess the impact of making semiautomatic external defibrillators (AEDs) available for use on airline passengers with cardiac arrest. AEDs were installed on international Qantas aircraft and at major terminals, selected crew were trained in their use, and all crew members were trained in cardiopulmonary resuscitation. Supervision was provided by medical volunteers or (remotely) by airline physicians. During a 64-month period, AEDs were used on 109 occasions: 63 times for monitoring an acutely ill passenger and 46 times for cardiac arrest. Twenty-seven episodes of cardiac arrest occurred in aircraft, often (11 of 27 [41%]) unwitnessed, and they were usually (21 of 27 [78%]) associated with asystole or pulseless idioventricular rhythm. All 19 arrests in terminals were witnessed; VF was present in 17 (89%). Overall, defibrillation was initially successful in 21 of 23 cases (91%). Long-term survival from VF was achieved in 26% (2 of 6 in aircraft and 4 of 17 in terminals). The ability to monitor cardiac rhythm aided decisions on diversion, which was avoided in most passengers with asystole or idioventricular rhythm. AEDs in aircraft and terminals, with appropriate crew training, are helpful in the management of cardiac emergencies. Survival from VF is practicable and is comparable with the most effective prehospital ambulance emergency services. Costly aircraft diversions can be avoided in clearly futile situations, enhancing the cost-effectiveness of the program.

The Effect of Semi-Automatic External Defibrillation by Emergency Medical Technicians on Survival After Out-Of-Hospital Cardiac Arrest: An Observational Study in Urban and Rural Areas in Belgium

SummaryThe introduction of semi-automatic external defibrillators (SAEDs) allowed emergency medical technicians (EMTs) to deliver electroshocks in cases of out-of-hospital ventricular fibrillation (VF) or ventricular tachycardia (VT), often many minutes before the arrival of the mobile intensive care unit (MICU) team. In this observational study we report on the results obtained by the EMTs from the fire departments of Gent, Aalter and Brugge.In Gent, an SAED project started in May 1991. By December 1995, the SAED’s electrodes had been attached in 367 cardiac arrest patients. The first rhythm detected by the device was asystole or electromechanical dissociation (EMD) in 241 patients (66%): only 5 of these patients survived to hospital discharge (2%). In the remaining 126 VF/VT cases (34%) the survival rate was 21% (26/126). In 14 of these 26 patients the shock(s) delivered by the EMTs restored spontaneous circulation before the arrival of the MICU team, with only venous cannulation and/or intubation being performed by the MICU team. In 4 other VF patients, the shock(s) delivered by EMTs converted the VF, with the MICU team successfully taking care of VF/VT relapses or postcountershock EMD. In the remaining 8 VF/VT cases, only the MICU attempts could resuscitate the patient. The SAED project in Aalter was set up in April 1993. By December 1995, care was taken for only 21 patients. None of the 4 VF/VT patients and the 17 asystole/EMD patients survived. In Brugge, there were 240 cardiac arrest cases treated with SAED between January 1991 and December 1995. Among the 89 VF/VT cases, there were 20 survivors (22%): 8 cases survived (hanks to SAED shock(s) delivered by EMTs, in 3 cases survival was due to the combination of SAED shock(s) by EMTs and extensive ALS treatment by the MICU team, and in 9 cases restoration of spontaneous circulation was only obtained after application of ALS techniques by the MICU team. This observational study seems to show a beneficial effect of the introduction of SAED in Gent and Brugge. In Aalter the number of treated cases is too low to draw conclusions. Anyhow, the global survival rate in the three areas remains low. Therefore, more efforts are needed to strengthen the other links of the chain of survival (early access to the emergency medical services-system, early basic cardiopulmonary resuscitation and early advanced life support).

P-49 Study of the efficiency of Semi Automatic External Defibrillation by the “100” ambulancemen during extrahospital cardiopulmonary resuscitation

P-49 Study of the efficiency of Semi Automatic External Defibrillation by the “100” ambulancemen during extrahospital cardiopulmonary resuscitation

Semi-automatic external defibrillation and implanted cardiac pacemakers: understanding the interactions during resuscitation

Many emergency medical service (EMS) systems are currently implementing semi-automatic external defibrillation (AED) by emergency medical technicians. Surprisingly little information is available on the possible interactions between AEDs and implanted cardiac pacemakers. Therefore, at present there are no clear guidelines for the use of AEDs on patients having a cardiac pacemaker. During resuscitation, multiple interactions between pacemakers and AEDs are possible. External defibrillation can cause damage to several functions of the pacemaker. On the other hand, the presence of pacemaker spikes during cardiac arrest might prohibit recognition of the ventricular fibrillation by the AED. We report on two resuscitation attempts in which the interaction between the ventricular fibrillation, an implanted dual chamber pacemaker and the AED was decisive for the defibrillation success. A clear understanding of these possible interactions is necessary for the further refining of diagnostic algorithms and clinical strategies of prehospital defibrillation.

P145 Semi-automatic external defibrillator (AED): The Italian experience

P145 Semi-automatic external defibrillator (AED): The Italian experience

Semi-automatic external defibrillator (AED): the italian experience

Semi-automatic external defibrillator (AED): the italian experience

Flying squad response to out of hospital cardiac arrest — A decade of experience

The Flying Squad (MEDIC I) based at the Royal Infirmary, Edinburgh, commenced operation in 1980. The MEDIC I response to out of hospital non-traumatic cardiac arrest over the past decade is reported. On-scene resuscitation was attempted in 384 patients. A total of 149 (39%) patients were successfully resuscitated and transferred to hospital. Thirty-six (9.4%) patients survived to discharge from hospital. Patients receiving basic life support prior to the arrival of MEDIC I and in ventricular fibrillation had a survival rate of 14.5% (25/174). During 1988-89, 21 patients were initially attended by ambulance crews equipped with semi-automatic external defibrillators and eight (38%) of these patients survived. The response of a hospital-based flying squad to support trained ambulance crews, especially when equipped with a defibrillator may provide an economically and operationally feasible alternative to training all first responders in the full range of paramedic skills.

Flying squad response to out-of-hospital cardiac arrest--a decade of experience.

The Flying Squad (MEDIC I) based at the Royal Infirmary, Edinburgh, commenced operation in 1980. The MEDIC I response to out of hospital non-traumatic cardiac arrest over the past decade is reported. On-scene resuscitation was attempted in 384 patients. A total of 149 (39%) patients were successfully resuscitated and transferred to hospital. Thirty-six (9.4%) patients survived to discharge from hospital. Patients receiving basic life support prior to the arrival of MEDIC I and in ventricular fibrillation had a survival rate of 14.5% (25/174). During 1988-89, 21 patients were initially attended by ambulance crews equipped with semi-automatic external defibrillators and eight (38%) of these patients survived. The response of a hospital-based flying squad to support trained ambulance crews, especially when equipped with a defibrillator may provide an economically and operationally feasible alternative to training all first responders in the full range of paramedic skills.