Discussion on automated external defibrillator configuration optimization strategy of rapidly developing city: a case study of Bao'an, Shenzhen / 中华危重病急救医学

Objective:To explore the automated external defibrillator (AED) configuration optimization strategy in line with the characteristics of the rapidly developing cities by analyzing the actual coverage of AED in Bao'an District based on the real world data of out-of-hospital cardiac arrest (OHCA) in Bao'an District, Shenzhen City.Methods:The data of cardiac arrest database registered in Bao'an District of Shenzhen City from March 1, 2019 to February 29, 2020 were included in a retrospective observational study. The AED coverage of public and non-public areas was analyzed by calculating the minimum distance between the occurrence place of each OHCA event and the nearest AED. The minimum distance ≤100 m was set as AED coverage, and the minimum distance > 100 m was set as non-AED coverage. It was assumed that one AED was configured for each OHCA hotspot area, then the AED coverage changes were analyzed. Based on the actual situation that the AED in schools, governments, sports venues, subways, tourist attractions and parks of public areas in Bao'an District could not be obtained at any time within 24 hours, it was assumed that all AED in the public areas could be obtained at any time within 24 hours, the impact of AED available at any time on AED coverage was analyzed.Results:A total of 525 cases of OHCA were enrolled. The highest incidence of OHCA was found in residential and industrial areas [54.5% (286/525) and 14.3% (75/525), respectively]. There were 252 AED in Bao'an District, Shenzhen, and 115 OHCA events occurred within the coverage area of AED. Even if all AED met the ideal state that could be obtained at any time within 24 hours, the coverage rate was only 21.9% (115/525). The AED coverage rate of the public areas and non-public areas was 31.6% (37/117) and 19.1% (78/408) respectively, with uneven distribution, and the AED coverage rate of non-public areas was low. Assuming that the residential community and industrial zone with more than 2 OHCA cases were respectively equipped with one AED, the coverage rate of AED in the non-public areas increased from 19.1% (78/408) to 28.2% (115/408), basically meeting the requirement that AED could be obtained at any time when OHCA events occurred. Some AED in the public areas of Bao'an District were not available at any time within 24 hours. If the ideal state that all AED in the public area could be obtained at any time within 24 hours could be achieved, the AED coverage rate of all regions increased from 16.8% (88/525) to 21.9% (115/525), the AED coverage rate of the public areas increased from 29.1% (34/117) to 31.6% (37/117), the AED coverage rate of the non-public areas increased from 13.2% (54/408) to 19.1% (78/408).Conclusions:AED configuration in Bao'an District was unevenly distributed, and the coverage rate of AED in non-public areas was low. The allocation strategy for AED in fast-growing cities like Shenzhen should be as follows: on the premise of ensuring AED availability for 24 hours, priority should be given to covering the number of AED in the non-public areas including residential communities and industrial zones; AED is available in the public areas for 24 hours.

Layperson’s performance on an unconversant type of AED device: A prospective crossover simulation experimental study / 世界急诊医学杂志（英文）

@#BACKGROUND: Diverse models of automated external defibrillators (AEDs) possess distinctive features. This study aimed to investigate whether laypersons trained with one type of AED could intelligently use another initial contact type of AED with varying features. METHODS: This was a prospective crossover simulation experimental study conducted among college students. Subjects were randomly trained with either AED1 (AED1 group) or AED2 (AED2 group), and the AED operation performance was evaluated individually (Phase I test). At the 6-month follow-up AED performance test (Phase II test), half of the subjects were randomly switched to use another type of AED, which formed two switches (Switch A: AED1-1 group vs. AED2-1 group; Switch B: AED2-2 group vs. AED1-2 group). RESULTS: A total of 224 college students participated in the study. In the phase I test, a significantly higher proportion of successful defibrillation and shorter shock delivery time to achieve successful defibrillation was observed in the AED2 group than in the AED1 group. In the phase II test, no statistical differences were observed in the proportion of successful defibrillation in Switch A (51.4% vs. 36.6%, P=0.19) and Switch B (78.0% vs. 53.7%, P=0.08). The median shock delivery time within participants achieving successful defibrillation was significantly longer in the switched group than that of the initial group in both Switch A (89 [81–107] s vs. 124 [95–135] s, P=0.006) and Switch B (68 [61.5–81.5] s vs. 95.5 [55–131] s, P<0.001). CONCLUSION: College students were able to effectively use AEDs different from those used in the initial training after six months, although the time to shock delivery was prolonged.

National survey of awareness and training experience of automated external defibrillator

OBJECTIVE: Public concerns and awareness of automated external defibrillators (AEDs) are essential for improving the survival outcomes of out-of-hospital cardiac arrest (OHCA) in the community. On the other hand, the proportion of OHCA, in which AED is used in a prehospital setting, is very low in Korea. The aim of this study was to identify the barriers and training issues of AEDs. METHODS: A nationwide population-based survey was conducted to analyze the current public trends in AED awareness, training, and intention to use in 2017 (n=506). The barriers and training issues of AEDs were then documented. For trend analysis, previous tri-temporal surveys were obtained in 2007, 2011, and 2015. RESULTS: Public awareness of AEDs has increased: from 5.8% in 2007, to 30.6% in 2011, 82.6% in 2015, and 79.4% in 2017 (P<0.001). The training experience of AEDs has increased over time: from 0.5% in 2007 to 8.2% in 2011 and 33.2% in 2017. Thirty-two percent of respondents knew how and where to find the AEDs, but only 12.5% were able to certainly locate their public-access AED near their residency or work places. The reasons for being unwilling to use the AED included not knowing how to use (65.0%), fear of causing harm to the victim (21.3%), and legal liability (11.7%). CONCLUSION: Not knowing the location of AED and how to use it, and being unaware of the Good Samaritan Law were the major barriers to public access defibrillation. Further research is urgently needed if AEDs are to be increased and more lives saved.

Prevention of sudden cardiac death in athletes, sportspersons and marathoners in India

The annual incidence of sudden cardiac death (SCD) in athletes is significantly lower than the general population. However, when SCD occurs in an athlete during sporting event or training, it sends shockwaves in the society and raises questions about cardiovascular effects of sports and exercise. This document reviews the causes and mechanism of SCD in sports and exercise in young and older athletes. In the Indian context, we suggest a ‘pre-participation screening’ of young and older athletes and consider a ‘supervised, graded exercise regime’ for the uninitiated, older sports participant. Finally, the document proposes medical infrastructure required to successfully revive a victim of sudden cardiac arrest during a sporting event.

Automated External Defibrillator (AED) Use Among Paramedics in the Emergency Department – What are the Obstacles in Using the Automated External Defibrillator in the Pre-Hospital Care Settings?

This study determined factors that influence usage of automated external defibrillation (AED) on out-of-hospital cardiac arrest among paramedics in Emergency Department of Universiti Kebangsaan Malaysia Medical Centre (UKMMC). It was a cross sectional prospective study conducted between December 2013 and January 2014. Paramedics from Emergency Department were enrolled and assessed using the self-filled questionnaire consisting of multiple sections including knowledge assessment, training and practice. In total, 53 paramedics participated in this study. Only 62% participants used AEDs previously. Not more than 83% participants admitted that they would use it if required. A positive correlation was observed between age and work experience with knowledge on AED usage (p=0.001 and p=0.005, respectively). Government’s institute graduates possess better knowledge and higher confidence level than private institutions graduates (p<0.001). Positive correlation existed between working experience and confidence level in deciding to use (p=0.006), application (p=0.019) and troubleshooting in regards of AED use (p=0.002). The main factor for low confidence level of AED use was lack of training (73.6%) which resulted in reduced confidence to initiate use (45.3%). Eighty eight percent agreed that training is essential before any AED use. Forty one percent felt that Malaysian public is not ready for AEDs use. As a conclusion, AED usage and knowledge among paramedics is still poor and further training is crucial for the improvement of pre-hospital care in Malaysia.

Characterization of available automated external defibrillators in the market based on the product manuals in 2014 / 世界急诊医学杂志（英文）

@#BACKGROUND: To popularize the wide-spread use of automated external defibrillator (AED) to save life in sudden cardiac arrest, we compared the strength and weakness of different types of AEDs to enable a sound selection based on regional requirement. METHODS: This was a retrospective descriptive study. Different types of AEDs were compared according to the information of AEDs from manuals and brochures provided by the manufacturers. Fifteen types of AEDs were divided into 3 groups, basic, intermediate and advanced. RESULTS: Lifeline? AUTO AED had the best performance in price, portability and user-friendly among AEDs of basic level. It required less time for shock charging. Samaritan PAD defibrillator was superior in price, portability, durability and characteristic among AEDs of intermediate level. It had the longest warranty and highest protection against water and dust. Lifeline? PRO AED had the best performance in most of the criteria among AEDs of advanced level and offered CPR video and manual mode for laypersons and clinicians respectively. CONCLUSION: Lifeline? AUTO AED, Samaritan PAD defibril ator, Lifeline? PRO AED are superior in AEDs of basic, intermediate and advanced levels, respectively. A feasible AED may be chosen by users according to the regional requirement and the current information about the best available products.

Accuracy of the Automatic External Defibrillator on an Electric Mattress: Simulation Study

PURPOSE: The accuracy of the automated external defibrillator (AED) is susceptible to environmental factors such as vibration, motion artifacts, and electromagnetic interference (EMI). The purpose of this study was to evaluate whether the EMI produced by an electric mattress can affect the performance of AEDs. METHODS: Four commercially available AEDs were evaluated under four ECG rhythm settings (normal sinus rhythm, asystole, ventricular fibrillation, and ventricular tachycardia) with or without an electric mattress. The sensitivity, specificity, positive predictable value, negative predictable value, and accuracy of AEDs were calculated to differentiate shockable from nonshockable rhythms. Times required to interpret the ECGs were checked with and without an electric mattress. RESULTS: A total of 320 tests were recorded, and each AED was tested a total of 80 times. Depending on the AED model used on an electric mattress, sensitivity ranged from 55% to 90% with a specificity of 100%, and accuracy ranged from 77.5% to 95%. For some AEDs, sensitivity was reduced compared to the control. Although there was no significant difference in times required to interpret ECG signals with or without an electric mattress, some AEDs detected a relatively small interference as motion artifacts when an electric mattress was used. All recorded ECG rhythms on an electric mattress showed baseline artifacts and these artifacts lessened with increasing distance from an electric mattress. CONCLUSION: This study suggests that an electric mattress could affect the shockable rhythm performance of some AEDs. Electromagnetic interference generated by an electric mattress could interfere with the ability of some commercial AEDs to correctly interpret stimulated ECG rhythms and provide appropriate defibrillation.

Accuracy of the Automatic External Defibrillator on an Electric Mattress: Simulation Study

PURPOSE: The accuracy of the automated external defibrillator (AED) is susceptible to environmental factors such as vibration, motion artifacts, and electromagnetic interference (EMI). The purpose of this study was to evaluate whether the EMI produced by an electric mattress can affect the performance of AEDs. METHODS: Four commercially available AEDs were evaluated under four ECG rhythm settings (normal sinus rhythm, asystole, ventricular fibrillation, and ventricular tachycardia) with or without an electric mattress. The sensitivity, specificity, positive predictable value, negative predictable value, and accuracy of AEDs were calculated to differentiate shockable from nonshockable rhythms. Times required to interpret the ECGs were checked with and without an electric mattress. RESULTS: A total of 320 tests were recorded, and each AED was tested a total of 80 times. Depending on the AED model used on an electric mattress, sensitivity ranged from 55% to 90% with a specificity of 100%, and accuracy ranged from 77.5% to 95%. For some AEDs, sensitivity was reduced compared to the control. Although there was no significant difference in times required to interpret ECG signals with or without an electric mattress, some AEDs detected a relatively small interference as motion artifacts when an electric mattress was used. All recorded ECG rhythms on an electric mattress showed baseline artifacts and these artifacts lessened with increasing distance from an electric mattress. CONCLUSION: This study suggests that an electric mattress could affect the shockable rhythm performance of some AEDs. Electromagnetic interference generated by an electric mattress could interfere with the ability of some commercial AEDs to correctly interpret stimulated ECG rhythms and provide appropriate defibrillation.

Comparing the fully-automated external defibrillator and semi-automated external defibrillator used by laypersons: A simulation study

PURPOSE: This study compared the performance between the fully-automated external defibrillator (F-AED) and the semi-automated external defibrillator (S-AED) when used by laypersons. METHODS: Thirty-three laypersons participated in a mannequin simulation study as part of Cardio-Pulmonary Resuscitation (CPR) training courses. After 30 minutes of didactic education for the Automated External Defibrillator (AED), they watched a video on how to use the fully-automated external defibrillator (F-AED) and a semi-automated external defibrillator (S-AED) instead of a hands-on education. Laypersons performed the S-AED first, then the F-AED. Performances and shock delivery time intervals were recorded and evaluated. RESULTS: The performances in shock delivery were better with the F-AED, although the overall performance was statistically insignificant. In terms of shock delivery interval, the F-AED was shorter than the S-AED (54.48+/-2.84 sec vs. 64.76+/-3.57 sec, respectively, p<0.01). In the post survey, F-AED had a higher preference (F-AED vs. S-AED 23(70%) vs. 5(15%), respectively, p<0.001). CONCLUSION: The F-AED had a better performance and shorter shock delivery time interval than the S-AED. The F-AED should thus be considered for use, outside of the hospital, on cardiac arrest patients for early defibrillation.

Paro cardiorrespiratorio prehospitalario: Desfibrilación de acceso público / Prehospital Cardiac Arrest: Public-Access Defibrillation / Prehospital Cardiac Arrest: Public-Access Defibrillation

La enfermedad cardiovascular es la principal causa de muerte en países de concentración urbana como el nuestro. La mayoría de esas muertes se producirán en el ámbito prehospitalario y sólo una rápida respuesta con maniobras de resucitación cardiopulmonar y desfibrilación precoz puede lograr una sobrevida aceptable. En esta presentación se describe el caso de un individuo que sufrió un paro cardiorrespiratorio mientras circulaba por la vía pública y que fue rescatado exitosamente gracias a la desfibrilación precoz realizada con un desfibrilador externo automático. Se incluyen los registros gráficos del evento y se enfatizan consideraciones sobre la importancia del concepto de acceso público a la desfibrilación.

Cardiovascular disease is the leading cause of death in countries like ours with urban areas. Most of these deaths occur in the prehospital setting and a rapid response with cardiopulmonary resuscitation and early defibrillation are necessary to maximize survival. We describe the case of a subject who suffered a cardiac arrest while walking in the public thoroughfare and was successfully resuscitated with early defibrillation using and automated external defibrillator. The electrocardiograms obtained during the episode are included and the importance of the concept of public access defibrillation is emphasized.

Effect of automated external defibrillator on cardiopulmonary resuscitation and cardiac function / 中华急诊医学杂志

Objective To investigate the efficiency and safety of the automated external defibrillator (AED); and to compare the defibrillating efficacy between the domestic AED and the imported AED. Method Fourteen Peking white swine weighed (30 ± 1 ) kg, were anaesthetized and arterial cannula was inserted into the left femoral artery for collecting blood samples and measuring artery blood pressure, cardiac output (CO) and external vascular lung water index (EVWI) by using PiCCO monitor, and another cannula was inserted into the left femoral vein to place an electrode as a temporary pace maker, and then ventricular fibrillation (VF) was induced by using a programmed electrical stimulation instrument. The swine were divided into two groups randomly ( random number) after VF was confirmed by electrocardio-monitor,and the domestic made AED (M group, n = 7) or imported AED (Z group, n = 7) were used respectively in 7 swine of each group. The electrodes of defibrillator were stuck to the precordium and sternum separately, and defibrillation was delivered by the AED signal. The entire procedure of defibrillation was repeated four times. The number of defibrillation delivery required to get normal cardiac rhythm was recorded. Twenty minutes after restoration of spontaneous circulation (ROSC), blood sample was taken to measure myocardial enzyme. The CO and EVWI were measured too. Measurement data was analyzed by repeated ANOVA and enumeration data was analyzed by Chi-square test. A value of P ＜0.05 was regarded as being significant statistical difference. Results There were 54 episodes of VF induced in 14 swine and only one swine in Z group was dead after 2nd episode of VF, resulting in 98.1% success rate of resuscitation. There were 37 defibrillation deliveries given to swine of M group, and 75.0% produced normal cardiac rhythm after the first delivery of defibrillation,whereas 80.0% in Z group after 32 defibrillation deliveries. The length of time from AED turned on to the recognition of ECG signal of VF was (29 ± 1 ) s. There were 2 occasions in both groups that the AEDs failed to recognize the VF signal emerged on ECG after the first induction of VF by electrical shock. Similarly, there were 2 occasions in Z group that the AED incorrectly recognized the signal of ventricular tachycardia as that of VF, but no harm was done after defibrillation delivery given following the signal of AED. During the entire course of experiment, heart rate,blood pressure and CO of all survived swine were stable,but the EVWI and myoglobin (MYO) gradually increased as time elapsed until the 3rd or 4th episode of VF leading to significant differences from the original ones. There were no significant differences in all biomarkers between two groups. Conclusions The VF can be ceased by AED safely and efficiently. There are no significant differences in signal recognition, efficacy of defibrillation and myocardial injury found between the domestic made AED and imported AED; but AED may not be good to be recommended to the professional staff of resuscitation because of its incorrect reorganization of ECG owing to over-automation.

Achievements of a basic life support course taught by medical students / 医学教育

1) Osaka City University Medical School provides basic life support courses in the Skills Simulation Center. Most instructors are members of the Life Support Club, a medical students' extracurricular activity.2) We investigated the numbers and opinions of participants(December 2006 through July 2008). The numbers of trainee and instructors were 1071 and 1223, respectively. The student instructors considered their activities worthwhile.3) The trainees highly appreciated the student instructors and showed that the effectiveness of training was excellent. Our results show that basic life support courses taught by medical students are beneficial for both trainees and student instructors.

Accuracy of Automated External Defibrillators During Ambulance Transport: Simulation Study

PURPOSE: Current resuscitation guideline recommends not using the automated external defibrillator (AED) in a running ambulance, because artifact arising from movement of the ambulance can interfere with rhythm analysis of AED and can simulate ventricular fibrillation (VF). This study was conducted to determine whether the AED can be operated correctly in a running ambulance. METHODS: Five AEDs were tested for their sensitivity, specificity, positive/negative predictive value, and accuracy. Each AED was connected to a manikin randomly simulating coarse and fine VF, asystole, and normal sinus rhythm, and each rhythm was analyzed 5 times by AEDs on the highway. Data about the shock recommendation given and delivery time interval from analysis to shock were collected. ECGs were also downloaded during the analysis time for a normal volunteer to search for baseline artifacts. RESULTS: All AEDs recommended shock delivery correctly for the simulated rhythms whether the ambulance was stopped (0 km/h) or running on unpaved road (20 km/h). The sensitivity, specificity, positive/negative predictive value, and accuracy of AEDs on the highway (100 km/h) were similar to those obtained in previous studies on AED performance in pre-hospital settings. The recorded ECG rhythm of a volunteer in a running car showed no baseline artifacts. CONCLUSION: All AEDs recommended shock delivery correctly in a running ambulance. Therefore, the current recommendation of not using the AED on a running ambulance should be reconsidered.

A Trial of an Objective Structured Clinical Examination for Basic Life Support Using an Automated External Defibrillator / 医学教育

We administered an objective structured clinical examination (OSCE) for basic life support (BLS) using an automated external defibrillator (AED) to fourth-year students of the Akita University School of Medicine. Although medical school graduates should be proficient in advanced cardiovascular life support techniques, this program is still on a trial basis. Furthermore, the general public should also be able to perform BLS. We believe that an OSCE for BLS using an AED is imperative, as Guidelines 2000 include defibrillation under the category of BLS. We formulated the questions, examination method, and standards for evaluation and arranged the schedule for the OSCE. The OSCE was administered without major problems, although some weaknesses were identified. High objectivity on the OSCE can be obtained only by constant evaluation under consistent conditions; however, the variability of evaluation between examiners on the OSCE reduced objectivity. After correcting this problem, the OSCE for BLS with an AED should be used throughout Japan.

Role and Application of Automated External Defibrillator / 医疗卫生装备

Automated external defibrillator(AED) is introduced including its practical functions,easy operation,and its role in the Public Access Defibrillation.The combination of AED with cardiopulmonary resuscitation is clarified,i.e.rescuers ought to perform early defibrillation toward the victim experiencing sudden cardiac arrest with shockable rhythm as rapidly as possible,and then turn to chest compressions without delay.At last,the existing situation and the shortcomings in the utilization of AED in China are pointed out along with its prospects.

Prospective Application of Automated External Defibrillator in Inferior Troops / 医疗卫生装备

The present situation of automated external defibrillator in inferior troops is analyzed.The shortcomings of current equipment are explained from both the troop itself and outer objective conditions from the aspects including false operation,low efficiency,use limited,etc.The potential prospects are given for the application of automated external defibrillator in inferior troops the inferior troops bring in the automated erternal defibrillator,not only the technical personnel,but also the sergent can operate it,making the warking more effectively.[Chinese Medical Equipment Journal,2008,29(2):72-73]