Smartphone based alerting of first responders during the corona virus disease-19 pandemic: An observational study

Automatic measurement of departing times in smartphone alerting systems: A pilot study

AIM

Smartphone alerting systems (SAS) alert volunteers in close vicinity of suspected out-of-hospital cardiac arrest. Some systems use sophisticated algorithms to select those who will probably arrive first. Precise estimation of departing times and travel times may help to further improve algorithms. We developed a global positioning system (GPS) based method for automatic measurements of departing times. The aim of this pilot study was to evaluate feasibility and precision of the method.

METHODS

Region of Lifesavers alerting app (iOS/ Android, version 3.0, FirstAED ApS, Denmark) was used in this study. 27 experiments were performed with 9 students, who were instructed to stay in their flats during the study days. A geofence was set for each alarm in the alerting system with a radius of 10 m (8 cases), 15 m (10 cases), and 20 m (9 cases) around the GPS position at which the alarm was accepted in the app. The system logged responders as being departed when the smartphone position was registered outside the geofence. The students were instructed to manually start a stopwatch at the time of the alert and to stop the stopwatch once they had entered the street in front of their flat.

RESULTS

The median difference between automatically and manually retrieved times were -16 seconds [interquartile range IQR 50 seconds] (geofence 10 m), 30 seconds [IQR 25 seconds] (15 m), and 20 seconds [IQR 13 seconds] (20 m), respectively. The 20 m geofence was associated with the smallest interquartile range.

CONCLUSION

Departing times of volunteer responders in SAS can be retrieved automatically using GPS and a geofence.

Out-of-ospital cardiac arrest & Smartphonespndr trial ( Trial): Methodology and study protocol of a pre-post-design trial of the effect of implementing a smartphone alerting system on survival in out-of-hospital cardiac arrest

Background

Since 2021, international guidelines for cardiopulmonary resuscitation recommend the implementation of so-called "life-saving systems". These systems include smartphone alerting systems (SAS), which enable dispatch centres to alert first responders via smartphone applications, who are in proximity of a suspected out-of-hospital cardiac arrest (OHCA). However, the effect of SAS on survival remains unknown.

Aim

The aim is to assess the rate of survival to hospital discharge in adult patients with OHCA not witnessed by emergency medical services (EMS): before and after SAS implementation.

Design

Multicentre, prospective, observational, intention-to-treat, pre-post design clinical trial.

Population

Adults (aged ≥ 18 years), OHCA not witnessed by EMS, no traumatic cause for cardiac arrest, cardiopulmonary resuscitation initiated or continued by EMS.

Setting

Dispatch-centre-based.

Outcomes

Primary: survival to hospital discharge. Secondary: time to first compression, rate of basic life support measures before EMS arrival, rate of patients with shockable rhythm at EMS arrival, Cerebral Performance Category at hospital discharge, and duration of hospital stay.

Sample size

Assuming an absolute difference in survival rates to hospital discharge of 4% in the two groups (11% before implementation of the SAS versus 15% after) and 80% power, and a type 1 error rate of 0.05, the required sample size is N = 1,109 patients per group (at least N = 2,218 evaluated patients in total).

Conclusions

The HEROES trial will investigate the effects of a SAS on the survival rate after OHCA.

Trial registration

German Clinical Trials Register (DRKS, ID: DRKS00032920).

Telephone cardiopulmonary resuscitation, first responder systems, cardiac arrest centers, and global campaigns to save lives

PURPOSE OF REVIEW

The latest resuscitation guidelines contain a new chapter, which focuses on systems improving care for patients with out-of-hospital cardiac arrest (OHCA). In this article, we describe recent developments regarding telephone cardiopulmonary resuscitation (CPR), first responder systems, cardiac arrest centers, and global campaigns.

RECENT FINDINGS

Telephone CPR has been implemented in many countries, and recent developments include artificial intelligence and video calls to improve dispatch assisted CPR. However, the degree of implementation is not yet satisfying. Smartphone alerting systems are effective in reducing the resuscitation-free interval, but many regions do not yet use this technology. Further improvements are needed to reduce response times. Cardiac arrest centers increase the survival chance after OHCA. Specific criteria need to be defined and professional societies should establish a certification process. Global campaigns are effective in reaching people around the world. However, we need to evaluate the effects of the campaigns.

SUMMARY

Telephone CPR, first responder systems, cardiac arrest centers, and global campaigns are highlighted in the recent resuscitation guidelines. However, the degree of implementation is not yet sufficient. We do not only need to implement these measures, but we should also aim to monitor the systems regarding their performance and further improve them.

How technology can save lives in cardiac arrest

PURPOSE OF REVIEW

Technology is being increasingly implemented in the fields of cardiac arrest and cardiopulmonary resuscitation. In this review, we describe how recent technological advances have been implemented in the chain of survival and their impact on outcomes after cardiac arrest. Breakthrough technologies that are likely to make an impact in the future are also presented.

RECENT FINDINGS

Technology is present in every link of the chain of survival, from prediction, prevention, and rapid recognition of cardiac arrest to early cardiopulmonary resuscitation and defibrillation. Mobile phone systems to notify citizen first responders of nearby out-of-hospital cardiac arrest have been implemented in numerous countries with improvement in bystanders' interventions and outcomes. Drones delivering automated external defibrillators and artificial intelligence to support the dispatcher in recognising cardiac arrest are already being used in real-life out-of-hospital cardiac arrest. Wearables, smart speakers, surveillance cameras, and artificial intelligence technologies are being developed and studied to prevent and recognize out-of-hospital and in-hospital cardiac arrest.

SUMMARY

This review highlights the importance of technology applied to every single step of the chain of survival to improve outcomes in cardiac arrest. Further research is needed to understand the best role of different technologies in the chain of survival and how these may ultimately improve outcomes.

Dispatching citizens as first responders to out-of-hospital cardiac arrests: a systematic review and meta-analysis

Mobile phone technologies to alert citizen first responders to out-of-hospital cardiac arrests (OHCAs) were implemented in numerous countries. This systematic review and meta-analysis aim to investigate whether activating citizen first responders increases bystanders' interventions and improves outcomes. We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to 24 November 2021, for studies comparing citizen first responders' activation versus standard emergency response in the case of OHCA. The primary outcome was survival at hospital discharge or 30 days. Secondary outcomes were discharge with favourable neurological outcome, bystander-initiated cardiopulmonary resuscitation (CPR), and the use of automated external defibrillators (AEDs) before ambulance arrival. Evidence certainty was evaluated with GRADE. Our search strategy yielded 1215 articles. After screening, we included 10 studies for a total of 23 351 patients. OHCAs for which citizen first responders were activated had higher rates of survival at hospital discharge or 30 days compared with standard emergency response [nine studies; 903/9978 (9.1%) vs. 1104/13 247 (8.3%); odds ratio (OR), 1.45; 95% confidence interval (CI), 1.21-1.74; P < 0.001], return of spontaneous circulation [nine studies; 2575/9169 (28%) vs. 3445/12 607 (27%); OR, 1.40; 95% CI, 1.07-1.81; P = 0.01], bystander-initiated CPR [eight studies; 5876/9074 (65%) vs. 6384/11 970 (53%); OR, 1.75; 95% CI, 1.43-2.15; P < 0.001], and AED use [eight studies; 654/9132 (7.2%) vs. 624/14 848 (4.2%); OR, 1.82; 95% CI, 1.31-2.53; P < 0.001], but similar rates of neurological intact discharge [three studies; 316/2685 (12%) vs. 276/2972 (9.3%); OR, 1.37; 95% CI, 0.81-2.33; P = 0.24]. Alerting citizen first responders to OHCA patients is associated with higher rates of bystander-initiated CPR, use of AED before ambulance arrival, and survival at hospital discharge or 30 days.

Activation of Citizen Responders to Out‐of‐Hospital Cardiac Arrest During the COVID‐19 Outbreak in Denmark 2020

Background

Little is known about how COVID‐19 influenced engagement of citizen responders dispatched to out‐of‐hospital cardiac arrest (OHCA) by a smartphone application. The objective was to describe and analyze the Danish Citizen Responder Program and bystander interventions (both citizen responders and nondispatched bystanders) during the first COVID‐19 lockdown in 2020.

Methods and Results

All OHCAs from January 1, 2020, to June 30, 2020, with citizen responder activation in 2 regions of Denmark were included. We compared citizen responder engagement for OHCA in the nonlockdown period (January 1, 2020, to March 10, 2020, and April 21, 2020, to June 30, 2020) with the lockdown period (March 11, 2020, to April 20, 2020). Data are displayed in the order lockdown versus nonlockdown period. Bystander cardiopulmonary resuscitation rates did not differ in the 2 periods (99% versus 92%; P=0.07). Bystander defibrillation (9% versus 14%; P=0.4) or return‐of‐spontaneous circulation (23% versus 23%; P=1.0) also did not differ. A similar amount of citizen responders accepted alarms during the lockdown (6 per alarm; interquartile range, 6) compared with the nonlockdown period (5 per alarm; interquartile range, 5) (P=0.05). More citizen responders reported performing chest‐compression‐only cardiopulmonary resuscitation during lockdown compared with nonlockdown (79% versus 59%; P=0.0029), whereas fewer performed standardized cardiopulmonary resuscitation, including ventilations (19% versus 38%; P=0.0061). Finally, during lockdown, more citizen responders reported being not psychologically affected by attending an OHCA compared with nonlockdown period (68% versus 56%; P<0.0001). Likewise, fewer reported being mildly affected during lockdown (26%) compared with nonlockdown (35%) (P=0.003).

Conclusions

The COVID‐19 lockdown in Denmark was not associated with decreased bystander‐initiated resuscitation in OHCAs attended by citizen responders.

First responder systems can stay operational under pandemic conditions: results of a European survey during the COVID-19 pandemic

Background

Dispatching first responders (FR) to out-of-hospital cardiac arrest in addition to the emergency medical service has shown to increase survival. The promising development of FR systems over the past years has been challenged by the outbreak of COVID-19. Whilst increased numbers and worse outcomes of cardiac arrests during the pandemic suggest a need for expansion of FR schemes, appropriate risk management is required to protect first responders and patients from contracting COVID-19. This study investigated how European FR schemes were affected by the pandemic and what measures were taken to protect patients and responders from COVID-19.

Methods

To identify FR schemes in Europe we conducted a literature search and a web search. The schemes were contacted and invited to answer an online questionnaire during the second wave of the pandemic (December 2020/ January 2021) in Europe.

Results

We have identified 135 FR schemes in 28 countries and included responses from 47 FR schemes in 16 countries. 25 schemes reported deactivation due to COVID-19 at some point, whilst 22 schemes continued to operate throughout the pandemic. 39 schemes communicated a pandemic-specific algorithm to their first responders. Before the COVID-19 outbreak 20 FR systems did not provide any personal protective equipment (PPE). After the outbreak 19 schemes still did not provide any PPE. The majority of schemes experienced falling numbers of accepted call outs and decreasing registrations of new volunteers. Six schemes reported of FR having contracted COVID-19 on a mission.

Conclusions

European FR schemes were considerably affected by the pandemic and exhibited a range of responses to protect patients and responders. Overall, FR schemes saw a decrease in activity, which was in stark contrast to the high demand caused by the increased incidence and mortality of OHCA during the pandemic. Given the important role FR play in the chain of survival, a balanced approach upholding the safety of patients and responders should be sought to keep FR schemes operational.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-022-00998-3.

Outcomes of out-of-hospital cardiac arrest in patients with SARS-CoV-2 infection: a systematic review and meta-analysis

INTRODUCTION

Out-of-hospital cardiac arrests increased during the COVID-19 pandemic and a direct mechanism of cardiac arrest in infected patients was hypothesized. Therefore, we conducted a systematic review and meta-analysis to assess outcomes of SARS-CoV-2 patients with out-of-hospital cardiac arrest.

METHODS

PubMed and EMBASE were searched up to April 05, 2021. We included studies comparing out-of-hospital cardiac arrests patients with suspected or confirmed SARS-CoV-2 infection versus noninfected patients. The primary outcome was survival at hospital discharge or at 30 days. Secondary outcomes included return of spontaneous circulation, cardiac arrest witnessed and occurring at home, bystander-initiated cardiopulmonary resuscitation, proportion of nonshockable rhythm and resuscitation attempted, and ambulance arrival time.

RESULTS

In the ten included studies, 18% (1341/7545) of out-of-hospital cardiac arrests occurred in patients with SARS-CoV-2 infection. Patients with out-of-hospital cardiac arrest and SARS-CoV-2 infection had reduced rates of survival (16/856 [1.9%] vs. 153/2344 [6.5%]; odds ratio (OR) = 0.33; 95% confidence interval (CI), 0.17-0.65; P = 0.001; I2 = 28%) and return of spontaneous circulation (188/861 [22%] vs. 640/2403 [27%]; OR = 0.75; 95% CI, 0.65-0.86; P < 0.001; I2 = 0%) when compared to noninfected patients. Ambulance arrived later (15 ± 10 vs. 13 ± 7.5 min; mean difference = 1.64; 95% CI, 0.41-2.88; P = 0.009; I2 = 61%) and nonshockable rhythms (744/803 [93%] vs. 1828/2217 [82%]; OR = 2.79; 95% CI, 2.08-3.73; P < 0.001; I2 = 0%) occurred more frequently. SARS-CoV-2 positive patients suffered a cardiac arrest at home more frequently (1186/1263 [94%] vs. 3598/4055 [89%]; OR = 1.86; 95% CI, 1.45-2.40; P<0.001; I2 = 0%) but witnessed rate (486/890 [55%] vs. 1385/2475 [56%]; OR = 0.97; 95% CI, 0.82-1.14; P = 0.63; I2 = 0%) and bystander-initiated cardiopulmonary resuscitation rate (439/828 [53%] vs. 1164/2304 [51%]; OR = 0.95; 95% CI, 0.73-1.24; P = 0.70; I2 = 53%) were similar.

CONCLUSIONS

One-fifth of out-of-hospital cardiac arrest patients had SARS-CoV-2 infection. These patients had low rates of return of spontaneous circulation and survival and were characterized by higher nonshockable rhythms but similar bystander-initiated cardiopulmonary resuscitation rate.

REVIEW REGISTRATION

PROSPERO - CRD42021243540.

Association of GPS-Based Logging and Manual Confirmation of the First Responders' Arrival Time in a Smartphone Alerting System: An Observational Study

The latest guidelines for cardiopulmonary resuscitation recommend that in case of suspected cardiac arrest first responders, who are close to the emergency location, should be notified by a smartphone app or text message. Smartphone Alerting Systems (SAS) aim to reduce the resuscitation-free interval. Thus, there is a need for uniform reporting of process times. Objective: To compare the response times in a SAS either by using global positioning system (GPS) data or by manual confirmation of first responders arriving at the scene. Methods: In the region of Freiburg (Southern Germany, 1,531 km², 493,000 inhabitants), a SAS is activated when the emergency dispatch center receives a call regarding suspected cardiac arrest. First responders who accept a mission are tracked using GPS. GPS-based times are logged for each responder when their position is within a radius of 100, 50, or 10 meters around the geographical position of the reported emergency. When arriving at the patient location, the first responders manually confirm "arrived" via their app. GPS-based and manually confirmed response arrival times were compared for all cases between 1 October and 31 March. Results: 192 missions with correct manual logging of the arrival time were included. GPS-based times were available in 175 (91%), 100 (52%), and 30 (16%) cases within radii of 100, 50, and 10 meters, respectively. GPS arrival times were approximately 1.5 minutes shorter when using a 100-meter radius and significantly longer when using a 10-meter radius. No difference was found for a 50-meter radius, but this would result in a lack of data in nearly half of the cases. Conclusion: GPS-based logging of arrival times leads to missing data. A 100-meter circle is associated with a low number of missing values, but 1.5 minutes must be added for the last 100 meters the first responder has to move. A wide range of the difference in response times (GPS vs. manual confirmation) must be regarded as a disadvantage. Manual confirmation reveals precise response times, but first responders may forget to confirm when they arrive. Trial registration: DRKS00016625 (14 April 2019).