A first city-wide early defibrillation project in a German city: 5-year results of the Bochum against sudden cardiac arrest study

Accessibility of automatic external defibrillators and survival rate of people with out-of-hospital cardiac arrest: A systematic review of real-world studies

OBJECTIVE

To evaluate the relationship between the accessibility of automatic external defibrillators (AEDs) and the survival rate of patients who have out-of-hospital cardiac arrest (OHCA).

METHODS

The systematic review was conducted according to the Cochrane Handbook of Systematic Reviews. We searched the Chinese and English literature databases from 2009 to 2019. Study selection and data collection were conducted by three reviewers. One-month survival rates of OHCA with different AEDs accessibility were estimated using meta-analysis.

RESULTS

Overall 16 studies with 55,537 participants were included. The overall one-month survival rate for OHCA was 27.4%. The one-month survival rate was 35.2% for people receiving AEDs within 5 min, 36.6% between 5 min to 10 min, and 28.4% for longer than 10 min. By distance between the location of the AEDs and the location of the cardiac arrest, the one-month survival rate was 37.1% for those ≤100 m, 22.0% for 100 m-200 m, and 12.8% for >200 m, respectively. The one-month survival rate was 39.3% in schools, sports venues and airports compared with 23.5% in other sites. The number of AEDs allocation was positively correlated, while the time and distance were negatively correlated with the one-month survival rate adjusted for other factors, but they were all non-significant correlations.

CONCLUSION

The improvement of accessibility of AEDs may increase the survival rate of OHCA and the survival rate may be higher in playgrounds, airports, and schools equipped with AEDs. However, the strength of evidence was limited by the considerably heterogeneity of included studies. Verification of these findings in further studies is warranted.

Safety and applicability of a pre-stage public access ventilator for trained laypersons: a proof of principle study

BACKGROUND

Contemporary resuscitation guidelines for basic life support recommend an immediate onset of cardiac compressions in case of cardiac arrest followed by rescue breaths. Effective ventilation is often omitted due to fear of doing harm and fear of infectious diseases. In order to improve ventilation a pre-stage of an automatic respirator was developed for use by laypersons.

METHODS

Fifty-two healthy volunteers were ventilated by means of a prototype respirator via a full-face mask in a pilot study. The pre-stage public access ventilator (PAV) consisted of a low-cost self-designed turbine, with sensors for differential pressure, flow, FO₂, FCO₂ and 3-axis acceleration measurement. Sensor outputs were used to control the respirator and to recognize conditions relevant for efficiency of ventilation and patients' safety. Different respiratory manoeuvres were applied: a) pressure controlled ventilation (PCV), b) PCV with controlled leakage and c) PCV with simulated airway occlusion. Sensor signals were analysed to detect leakage and airway occlusion. Detection based upon sensor signals was compared with evaluation based on clinical observation and additional parameters such as exhaled CO₂.

RESULTS

Pressure controlled ventilation could be realized in all volunteers. Leakage was recognized with 93.5% sensitivity and 93.5% specificity. Simulated airway occlusion was detected with 91.8% sensitivity and 91.7% specificity.

CONCLUSION

The pre-stage PAV was able to detect potential complications relevant for patients' safety such as leakage and airway occlusion in a proof of principle study. Prospectively, this device provides a respectable basis for the development of an automatic emergency respirator and may help to improve bystander resuscitation.

[Identification of common locations of out-of-hospital cardiac arrests in a German metropolis]

BACKGROUND

Most patients who suffer a sudden cardiac arrest initially have a shockable rhythm. Fast defibrillation and correctly performed cardiopulmonary resuscitation (CPR) are key factors for patient survival. These can be carried out by bystanders if an automated external defibrillator (AED) is available even in the absence of emergency services.

AIM

The place and time of CPRs in a German city were investigated and the strategic placement of emergency medical services and AEDs necessary were evaluated.

METHODS

All prehospital resuscitation attempts by Bochum's emergency services in 2011 were retrospectively analyzed. The city was divided into a grid, according to the city map to describe the location of every resuscitation. The distribution of cases was correlated to the city grid and time of day.

RESULTS

There were 299 cardiac arrests (mean age 74.2 ± 12.47 years; 59% of patients were male). Most resuscitations happened in a home environment between 8 am and 8 pm. There was a higher proportion of resuscitation attempts in grid squares with a high population density. Of the resuscitations in public places 16 of 47 (34%) happened in city district centers. In 72% of all cases, only a nonshockable rhythm could be documented as primary arrhythmia on the arrival of the emergency services. Of the 299 attempted resuscitations, a return of spontaneous circulation was achieved in 41%.

CONCLUSIONS

The knowledge about increased frequency of resuscitations in city centers provides insight for strategic placement of emergency devices and services in those areas. This can possibly minimize the time until first response and enables early defibrillation with AED in a first-responder program. In addition, bystanders should obtain clear instructions for resuscitation by the dispatcher of the emergency services.

[Ten years of early defibrillation: "Bochum against sudden cardiac death". Acceptance and critical analysis of using automated external defibrillators]

BACKGROUND

There is a comprehensive early defibrillation program in Bochum (Germany); since 2003 a total of 175 automated external defibrillators (AEDs) have been installed in urban areas by the city of Bochum and private companies. These were preferably installed in places with high foot traffic, e.g., public buildings, companies, and event/shopping centers. Approximately 15,000 laypeople who work in the vicinity of the AED locations were trained in the use of defibrillators and in basic resuscitation. In addition, rescue workers on fire trucks and medically trained personnel in physicians' medical practices were equipped as "first responders" with AEDs.

RESULTS

After an initiation phase, all available information after each AED use since August 2004 has been collected by the project coordinator. During the period of data collection (August 2004 to August 2013), an AED was used in a total of 17 patients who had suffered sudden cardiac death (SCD) under the project in Bochum. Eleven patients had primary ventricular fibrillation (VF). Six of these survived without neurological deficit. In another 6 patients, a nondefibrillatable rhythm disorder was diagnosed. The AEDs are reliable and showed impeccable rhythm analysis before the instructions to provide any necessary shock.

DISCUSSION

Compared to the number of existing units and an estimated number of 37-100 SCD/100,000, the use of the AEDs only 17 times appears relatively small. To improve the effectiveness of the AED program in Bochum, an analysis of the emergency service responses, which were necessary because of sudden circulatory collapse, is currently being performed. This will allow areas with an increased incidence of SCD to be identified and a plan for the strategic placement of AED and emergency services can be made.

Defibrillation in rural areas

AIM OF THE STUDY

Automated external defibrillation (AED) and public access defibrillation (PAD) have become cornerstones in the chain of survival in modern cardiopulmonary resuscitation. Most studies of AED and PAD have been performed in urban areas, and evidence is scarce for sparsely populated rural areas. The aim of this review was to review the literature and discuss treatment strategies for out-of-hospital cardiac arrest in rural areas.

METHODS

A Medline search was performed with the keywords automated external defibrillation (617 hits), public access defibrillation (256), and automated external defibrillator public (542). Of these 1415 abstracts and additional articles found by manually searching references, 92 articles were included in this nonsystematic review.

RESULTS

Early defibrillation is crucial for survival with good neurological outcome after cardiac arrest. Rapid defibrillation can be a challenge in sparsely populated and remote areas, where the incidence of cardiac arrest is low and rescuer response times can be long. The few studies performed in rural areas showed that the introduction of AED programs based on a 2-tier emergency medical system, consisting of Basic Life Support and Advanced Life Support teams, resulted in a decrease in collapse-to-defibrillation times and better survival of patients with out-of-hospital cardiac arrest.

CONCLUSIONS

In rural areas, introducing AED programs and a 2-tier emergency medical system may increase survival of out-of-hospital cardiac arrest patients. More studies on AED and PAD in rural areas are required.

Basic life support skills of high school students before and after cardiopulmonary resuscitation training: a longitudinal investigation

BACKGROUND

Immediate bystander cardiopulmonary resuscitation (CPR) significantly improves survival after a sudden cardiopulmonary collapse. This study assessed the basic life support (BLS) knowledge and performance of high school students before and after CPR training.

METHODS

This study included 132 teenagers (mean age 14.6 ± 1.4 years). Students completed a two-hour training course that provided theoretical background on sudden cardiac death (SCD) and a hands-on CPR tutorial. They were asked to perform BLS on a manikin to simulate an SCD scenario before the training. Afterwards, participants encountered the same scenario and completed a questionnaire for self-assessment of their pre- and post-training confidence. Four months later, we assessed the knowledge retention rate of the participants with a BLS performance score.

RESULTS

Before the training, 29.5% of students performed chest compressions as compared to 99.2% post-training (P < 0.05). At the four-month follow-up, 99% of students still performed correct chest compressions. The overall improvement, assessed by the BLS performance score, was also statistically significant (median of 4 and 10 pre- and post-training, respectively, P < 0.05). After the training, 99.2% stated that they felt confident about performing CPR, as compared to 26.9% (P < 0.05) before the training.

CONCLUSIONS

BLS training in high school seems highly effective considering the minimal amount of previous knowledge the students possess. We observed significant improvement and a good retention rate four months after training. Increasing the number of trained students may minimize the reluctance to conduct bystander CPR and increase the number of positive outcomes after sudden cardiopulmonary collapse.