Introduction Opioid use continues to cause harm and fatalities worldwide, despite ongoing preventive efforts. Early administration of the antidote naloxone can reverse potentially fatal opioid overdoses. Naloxone distribution programmes have increased survival across regions; however, additional efforts are needed to reduce opioid overdose mortality. One approach is to expand naloxone availability within communities.Methods and analysis The feasibility trial RESPONDER (REgion Skåne Preventing Overdose deaths through Naloxone Distribution with Emergency Runners) introduces a unique smartphone alerting system with community first responders (CFRs) dispatched to suspected opioid overdoses, in addition to the dispatch of regular emergency medical services (EMS). The aim is to investigate if trained CFRs can successfully recognise and reverse overdoses caused by opioids, prior to EMS arrival. The CFRs will be equipped with nasal naloxone and introduced to a novel naloxone algorithm during a study-specific course prior to participation. The course will offer practical training in basic life support and first aid, and it will also assess competence in the low-arousal approach, as well as the legal and ethical aspects of being a CFR.Main outcomes of the trial are feasibility, acceptability and safety. The trial will be performed in the region of Skåne, Sweden, between 1 September 2025 and 31 August 2027, with every CFR followed for up to 12 months.Ethics and dissemination The trial has been approved by the Swedish Ethical Review Authority (file number 2024–05887-01). Written informed consent is required from participating CFRs. This is also required of overdose survivors to allow the collection of clinical data from hospital records.Information regarding the project and recruitment will be disseminated via social media, news media, through the healthcare region’s communication channels and within public transportation hubs. Outcomes and analyses will be submitted to peer-reviewed journals.ClinicalTrials.gov-ID NCT07079241

BACKGROUND:Double sequential defibrillation (DSD) is a promising treatment for patients with out-of-hospital cardiac arrest (OHCA) with refractory ventricular fibrillation. The reproducibility and generalisability of previous studies are unknown. Additionally, whether DSD could improve survival if applied earlier has never been studied. The DoubleD trial aims to establish whether early DSD (as soon as possible after the first shock) is superior to standard defibrillation. This pilot study evaluated the safety and feasibility of this strategy in preparation for the main trial. METHODS:This Swedish, prehospital, open-label, randomised controlled external pilot trial enrolled patients with OHCA who were still in cardiac arrest after at least one defibrillation in the standard (anterior-lateral) position. Enrolment required two ambulances with manual defibrillators to be present. The inclusion goal was 40 patients, randomised 3:1 to early DSD (with a second defibrillator in the anterior-posterior position) or continued standard defibrillation. Data were collected from study questionnaires, medical charts and defibrillators. The main feasibility and safety outcomes were randomisation prior to three shocks, adherence to protocol and defibrillator malfunction. RESULTS:Between June 2024 and April 2025, 40 patients were randomised: 29 to early DSD and 11 to standard defibrillation. Overall, 32/40 (80%) were randomised before the third defibrillation. In the DSD group, 20/21 (95%) of patients who still had a shockable rhythm after randomisation received DSD. One case of treatment crossover occurred in both DSD and control groups. No defibrillator malfunctions or adverse events were observed. 30-day survival was 12/29 (41%) and 1/11 (9%) for the DSD and control group respectively. CONCLUSION:This is the first time that early DSD has been investigated in clinical practice. The strategy is feasible and appears to be safe. The findings have informed the design of the DoubleD main trial, powered to assess 30-day survival (NCT07174986). TRIAL REGISTRATION NUMBER:NCT06447805.

Background Persistent shockable rhythms (refractory to or recurring after three or more defibrillation attempts) are associated with poorer survival following out-of-hospital cardiac arrest, but little is known about this relationship following in-hospital cardiac arrest (IHCA). This study therefore explored the association between the number of defibrillation attempts and 30-day survival following IHCA.Method This was a national retrospective cohort study using prospectively collected data from the Swedish Registry for Cardiopulmonary Resuscitation. All cases of adult IHCA between 1 January 2010 and 31 December 2020 presenting with a shockable rhythm who received at least one defibrillation attempt were included. Comorbidity data originated from the Swedish National Patient Register. The exposure was the total number of defibrillation attempts and the primary outcome was 30-day survival. A descriptive analysis was performed, followed by multivariable logistic regression with adjustment for patient and cardiac arrest factors. Missing data were imputed.Results In total, 5325 IHCA cases were included. Persistent shockable rhythms occurred in 907 (17%) cases. 30-day survival decreased rapidly from 73% in patients receiving one defibrillation attempt to 41% in patients requiring four defibrillation attempts but subsequently plateaued with a minimum value (24%) at nine defibrillation attempts. An unwitnessed arrest (adjusted OR (aOR) 0.50, 95% CI 0.39 to 0.64), the absence of continuous cardiac monitoring (aOR 0.63, 95% CI 0.54 to 0.74) and a longer time to the first defibrillation attempt (aOR 0.89, 95% CI 0.86 to 0.91 per min) were potentially modifiable in-hospital factors associated with decreased survival.Conclusions A persistent shockable rhythm occurred in around one sixth of IHCAs with an initial shockable rhythm. Successive defibrillation attempts were associated with a rapid fall in survival followed by a plateau phase. These findings warrant further investigation, as patients with IHCA may also benefit from novel strategies to more rapidly terminate shockable rhythms.

Background:Drone dispatch in out-of-hospital cardiac arrest (OHCA) may shorten time to AED-attachment, however little is known about barriers for dispatchers to refer bystanders to retrieve and attach AEDs after delivery. This study aims to evaluate characteristics of drone delivered AEDs (D-AEDs) before and after implementing an educational bundle. Methods:This retrospective before-after observational study included all cases of D-AEDs arriving before EMS in suspected OHCA in Sweden (2020-2023). A supportive educational bundle was implemented at the dispatch centre in June 2022. Dispatcher-caller interactions were evaluated through audits of 112 voice logs using a modified CARES protocol. Results:Out of 123 deliveries of D-AEDs to suspected OHCAs before EMS arrival, 62 cases (50%) received bystander CPR. Dispatcher referral of bystanders to retrieve the D-AED occurred in totally 30/62 (48%) cases with an increase from 7/22 (32%) before, to 23/40 (58%) after bundle implementation. D-AED attachment occurred in 26/62 (42%), increase from 6/22 (27%) to 20/40 (50%). Cases with referral to a D-AED more often involved multiple bystanders onsite, 77% vs 23% in single bystander cases (p = 0.005). Median time difference between D-AED and EMS arrival was 03:14 (IQR 01:46-05:31) in the referral group and 01:49 (IQR 01:10-05:03) with non-referral (p = 0.8). Conclusion:Drones can deliver AEDs at an early stage in selected suspected OHCA cases. Implementation of an educational bundle at the dispatch centre was associated with increased dispatcher referral and bystander attachment of D-AEDs. D-AED referral was influenced by the number of bystanders onsite. When dispatcher referral occurred, D-AEDs were used in a majority of cases.

BACKGROUND:Severe coronary artery disease has been suggested as the main cause of out-of-hospital cardiac arrest (OHCA) requiring high number of defibrillations. We investigated the association between an increased degree of treatment refractoriness, defined as an increase in the number of defibrillation attempts, to coronary angiography findings and PCI in OHCA. METHODS:We included all OHCA patients in Sweden, 18-80 years old, with initial shockable rhythm during January 1, 2010, and December 31, 2019, who underwent coronary angiography. Patients were stratified by the number of defibrillations: 1-3, 4-6, 7-9, and ≥10, coronary angiography findings and interventions were described. RESULTS:In total, 3282 patients (19 % women, median age 64 years old) were included. Most patients had at least one significant stenosis, 80-67 %, with the highest proportions among those receiving 1-3 defibrillations. Acute coronary occlusions were present in similar proportions between the groups, 30-34 %. The proportion of patients receiving PCI was highest in the group with 1-3 defibrillations (68 %) and declined for those receiving more than 3 defibrillations, 57-52 %. There was a negative association between 1-year survival and increased number of defibrillations (75-39 %; p < 0.001), a difference unaffected when adjusting for coronary angiography findings and PCI in an adjusted multivariable model. CONCLUSIONS:In this nationwide study including all OHCA patients undergoing coronary angiography during a ten-year period, we can show that defibrillation attempts is not related to the burden of coronary artery disease and does not aid in selecting patients for coronary angiography following OHCA.

AIM:To assess the feasibility and safety of drone-delivered automated external defibrillators (AEDs) in real out-of-hospital cardiac arrests (OHCAs) in Denmark, addressing the critical need for timely defibrillation in OHCAs. METHODS:In this prospective clinical study in Aalborg, Denmark, an AED-carrying drone was dispatched for suspected OHCAs, from June 2022 to April 2023. The drone was stationed in an urban area (maximum flight-radius 6 km, covering 110,000 inhabitants) within designated airspace not requiring preflight approval from air-traffic control. Upon OHCA-suspicion, the emergency medical dispatcher activated the drone, which autonomously took off and flew beyond-visual-line-of-sight to the OHCA-location. On-site, a remote drone pilot (stationed cross-border) winched down the AED near the patient's location. Flights were restricted to dry weather, mean windspeeds < 8 m/s, and 8 am to 10 pm. RESULTS:Of 76 suspected OHCAs, 27 occurred during non-operating hours (nighttime). Of the remaining 49 OHCAs, 16 (33%) were eligible for drone take-off, all of which resulted in successful AED-delivery, without any adverse events. Weather caused 14 cancellations (29%), technical issues (dispatch centre, drone, or hangar problems) 13 (27%), and closed airspace 6 (12%). The median drone response time from activation to AED-delivery was 04:47 min (IQR 03:45-05:27), and the corresponding ambulance response time was 03:25 min (IQR 02:43-04:14). No drone-delivered AEDs were attached. CONCLUSION:This study demonstrates the safety and feasibility of drone-delivered AEDs to real OHCAs. Improved time to AED delivery was limited due to swift ambulance service, highlighting the importance of strategic AED drone placement.

Background: : Drones are able to deliver automated external defibrillators in cases of out-of-hospital cardiac arrest (OHCA) but can be deployed for other purposes. Our aim was to evaluate the feasibility of sending live photos to dispatch centres before arrival of other units during time-critical incidents. Methods: : In this retrospective observational study, the regional dispatch centre implemented a new service using five existing AED-drone systems covering an estimated 200 000 inhabitants in Sweden. Drones were deployed automatically over a 4-month study period (December 2022-April 2023) in emergency calls involving suspected OHCAs, traffic accidents and fires in buildings. Upon arrival at the scene, an overhead photo was taken and transmitted to the dispatch centre. Feasibility of providing photos in real time, and time delays intervals were examined. Results: : Overall, drones were deployed in 59/440 (13%) of all emergency calls: 26/59 (44%) of suspected OHCAs, 20/59 (34%) of traffic accidents, and 13/59 (22%) of fires in buildings. The main reasons for non-deployment were closed airspace and unfavourable weather conditions (68%). Drones arrived safely at the exact location in 58/59 cases (98%). Their overall median response time was 3:49 min, (IQR 3:18-4:26) vs. emergency medical services (EMS), 05:51 (IQR: 04:29-08:04) p-value for time difference between drone and EMS = 0,05. Drones arrived first on scene in 47/52 cases (90%) and the largest median time difference was found in suspected OHCAs 4:10 min, (IQR: 02:57-05:28). The time difference in the 5/52 (10%) cases when EMS arrived first the time difference was 5:18 min (IQR 2:19-7:38), p = NA. Photos were transmitted correctly in all 59 alerts. No adverse events occurred. Conclusion: : In a newly implemented drone dispatch service, drones were dispatched to 13% of relevant EMS calls. When drones were dispatched, they arrived at scene earlier than EMS services in 90% of cases. Drones were able to relay photos to the dispatch centre in all cases. Although severely affected by closed airspace and weather conditions, this novel method may facilitate additional decision-making information during time-critical incidents.

Introduction/aim Out-of-hospital cardiac arrest (OHCA) with shockable pulseless ventricular tachycardia or fibrillation not responding to defibrillation is a medical challenge. Novel treatment strategies have emerged for so-called refractory ventricular fibrillation not responding to three or more defibrillations but the evidence for optimal timing for these strategies is sparse. The primary aim of this observational study was to assess survival in relation to total numbers of defibrillations in OHCA. Methods This is a registry-based retrospective cohort study based on data reported by the emergency medical services to the Swedish Registry of Cardiopulmonary Resuscitation and the National Patient Registry. All OHCA patients aged 18 years or older with an initial shockable rhythm in Sweden from January 1, 2010 and December 31, 2020 were included. Exposure was total number of defibrillations, and primary outcome was survival to 30 days. Logistic regression was used to adjust for patient and resuscitation characteristics. Results Over the study period a total of 10,549 patients were included. Among them, 3,006 (28.5%) received only one shock, 1,665 (15.8%) two shocks, 1,336 (12.9%) three shocks, 1,064 (10.1%) four shocks and 3,478 (33.0%) five or more shocks. In the adjusted analysis an exponential decrease in the 30-day survival was found for each additional defibrillation. For patients receiving one, two, three and four defibrillations, the adjusted probability of survival was 42%, 36%, 30% and 25% respectively. Conclusions In this registry-based retrospective cohort study, additional defibrillations were associated with a lower survival. This association persisted after adjustments for patient and resuscitation characteristics.

BACKGROUND: The ongoing TANGO2 (Telephone Assisted CPR. AN evaluation of efficacy amonGst cOmpression only and standard CPR) trial is designed to evaluate whether compression-only cardiopulmonary resuscitation (CPR) by trained laypersons is noninferior to standard CPR in adult out-of-hospital cardiac arrest. This pilot study assesses feasibility, safety, and intermediate clinical outcomes as part of the larger TANGO2 survival trial. METHODS: Emergency medical dispatch calls of suspected out-of-hospital cardiac arrest were screened for inclusion at 18 dispatch centers in Sweden between January 1, 2017, and March 12, 2020. Inclusion criteria were witnessed event, bystander on the scene with previous CPR training, age above 18 years of age, and no signs of trauma, pregnancy, or intoxication. Cases were randomized 1:1 at the dispatch center to either instructions to perform compression-only CPR (intervention) or instructions to perform standard CPR (control). Feasibility included evaluation of inclusion, randomization, and adherence to protocol. Safety measures were time to emergency medical service dispatch CPR instructions, and to start of CPR, intermediate clinical outcome was defined as 1-day survival. RESULTS: Of 11 838 calls of suspected out-of-hospital cardiac arrest screened for inclusion, 2168 were randomized and 1250 (57.7%) were out-of-hospital cardiac arrests treated by the emergency medical service. Of these, 640 were assigned to intervention and 610 to control. Crossover from intervention to control occurred in 16.3% and from control to intervention in 18.5%. The median time from emergency call to ambulance dispatch was 1 minute and 36 s (interquartile range, 1.1–2.2) in the intervention group and 1 minute and 30 s (interquartile range, 1.1–2.2) in the control group. Survival to 1 day was 28.6% versus 28.4% ( P =0.984) for intervention and control, respectively. CONCLUSIONS: In this national randomized pilot trial, compression-only CPR versus standard CPR by trained laypersons was feasible. No differences in safety measures or short-term survival were found between the 2 strategies. Efforts to reduce crossover are important and may strengthen the ongoing main trial that will assess differences in long-term survival. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02401633.

AIMS:Previous studies have indicated a poorer survival among women following out-of-hospital cardiac arrest (OHCA), but the mechanisms explaining this difference remain largely uncertain.This study aimed to assess the survival after OHCA among women and men and explore the role of potential mediators, such as resuscitation characteristics, prior comorbidity, and socioeconomic factors. METHODS AND RESULTS:This was a population-based cohort study including emergency medical service-treated OHCA reported to the Swedish Registry for Cardiopulmonary Resuscitation in 2010-2020, linked to nationwide Swedish healthcare registries. The relative risks (RR) of 30-day survival were compared among women and men, and a mediation analysis was performed to investigate the importance of potential mediators. Total of 43 226 OHCAs were included, of which 14 249 (33.0%) were women. Women were older and had a lower proportion of shockable initial rhythm. The crude 30-day survival among women was 6.2% compared to 10.7% for men [RR 0.58, 95% confidence interval (CI) = 0.54-0.62]. Stepwise adjustment for shockable initial rhythm attenuated the association to RR 0.85 (95% CI = 0.79-0.91). Further adjustments for age and resuscitation factors attenuated the survival difference to null (RR 0.98; 95% CI = 0.92-1.05). Mediation analysis showed that shockable initial rhythm explained ∼50% of the negative association of female sex on survival. Older age and lower disposable income were the second and third most important variables, respectively. CONCLUSION:Women have a lower crude 30-day survival following OHCA compared to men. The poor prognosis is largely explained by a lower proportion of shockable initial rhythm, older age at presentation, and lower income.

ImportanceBrain injury is the leading cause of death following cardiac arrest and is associated with severe neurologic disabilities among survivors, with profound implications for patients and their families, as well as broader societal impacts. How these disabilities affect long-term survival is largely unknown.ObjectiveTo investigate whether complete neurologic recovery at hospital discharge after cardiac arrest is associated with better long-term survival compared with moderate or severe neurologic disabilities.Design, Setting, and ParticipantsThis cohort study used data from 4 mandatory national registers with structured and predefined data collection and nationwide coverage during a 10-year period in Sweden. Participants included adults who survived in-hospital cardiac arrest (IHCA) or out-of-hospital cardiac arrest (OHCA) beyond 30 days and who underwent predefined neurologic assessment conducted by health care professionals at hospital discharge using the Cerebral Performance Category (CPC) scale between January 2010 and December 2019. Patients were divided into 3 categories: complete recovery (CPC 1), moderate disabilities (CPC 2), and severe disabilities (CPC 3-4). Statistical analyses were performed in December 2023.ExposureCPC score at hospital discharge.Main Outcomes and MeasuresThe primary outcome was long-term survival among patients with CPC 1 compared with those with CPC 2 or CPC 3 or 4.ResultsA total of 9390 cardiac arrest survivors (median [IQR] age, 69 .0 [58.0-77.0] years; 6544 [69.7%] male) were included. The distribution of functional neurologic outcomes at discharge was 7374 patients (78.5%) with CPC 1, 1358 patients (14.5%) with CPC 2, and 658 patients (7.0%) with CPC 3 or 4. Survival proportions at 5 years were 73.8% (95% CI, 72.5%-75.0%) for patients with CPC 1, compared with 64.7% (95% CI, 62.4%-67.0%) for patients with CPC 2 and 54.2% (95% CI, 50.6%-57.8%) for patients with CPC 3 or 4. Compared with patients with CPC 1, there was significantly higher hazard of death for patients with CPC 2 (adjusted hazard ratio [aHR], 1.57 [95% CI, 1.40-1.75]) or CPC 3 or 4 (aHR, 2.46 [95% CI, 2.13-2.85]). Similar associations were seen in the OHCA and IHCA groups.Conclusions and RelevanceIn this cohort study of patients with cardiac arrest who survived beyond 30 days, complete neurologic recovery, defined as CPC 1 at discharge, was associated with better long-term survival compared with neurologic disabilities at the same time point.

BACKGROUND:Reducing the time to treatment by means of cardiopulmonary resuscitation (CPR) and defibrillation is essential to increasing survival after cardiac arrest. A novel method of dispatching drones for delivery of automated external defibrillators (AEDs) to the site of a suspected out-of-hospital cardiac arrest (OHCA) has been shown to be feasible, with the potential to shorten response times compared with the emergency medical services. However, little is known of dispatchers' experiences of using this novel methodology. METHODS:A qualitative semi-structured interview study with a phenomenological approach was used. Ten registered nurses employed at an emergency medical dispatch centre in Gothenburg, Sweden, were interviewed and the data was analysed by qualitative content analysis. The purpose was to explore dispatcher nurses' experiences of deliveries of AEDs by drones in cases of suspected OHCA. RESULTS:Three categories were formed. Nurses expressed varying compliance to the telephone-assisted protocol for dispatch of AED-equipped drones. They experienced uncertainty as to how long would be an acceptable interruption from the CPR protocol in order to retrieve a drone-delivered AED. The majority experienced that collegial support was important. Technical support, routines and training need to be improved to further optimise action in cases of drone-delivered AEDs handled by dispatcher nurses. CONCLUSIONS:Although telephone-assisted routines for drone dispatch in cases of OHCA were available, their use was rare. Registered nurses showed variable degrees of understanding of how to comply with these protocols. Collegial and technical support was considered important, alongside routines and training, which need to be improved to further support bystander use of drone-delivered AEDs. As the possibilities of using drones to deliver AEDs in cases of OHCA are explored more extensively globally, there is a good possibility that this study could be of benefit to other nations implementing similar methods. We present concrete aspects that are important to take into consideration when implementing this kind of methodology at dispatch centres.

Aim: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is time-dependent. To date, evidence-based training programmes for dispatchers are lacking. This study aimed to reach expert consensus on an educational bundle content for dispatchers to provide DA-CPR using the Delphi method. Method: An educational bundle was created by the Swedish Resuscitation Council consisting of three parts: e-learning on DA-CPR, basic life support training and audit of emergency out-of-hospital cardiac arrest calls. Thereafter, a two-round modified Delphi study was conducted between November 2022 and March 2023; 37 experts with broad clinical and/or scientific knowledge of DA-CPR were invited. In the first round, the experts participated in the e-learning module and answered a questionnaire with 13 closed and open questions, whereafter the e-learning part of the bundle was revised. In the second round, the revised e-learning part was evaluated using Likert scores (20 items). The predefined consensus level was set at 80%. Results: Delphi rounds one and two were assessed by 20 and 18 of the invited experts, respectively. In round one, 18 experts (18 of 20, 90%) stated that they did not miss any content in the programme. In round two, the scale-level content validity index based on the average method (S-CVI/AVE, 0.99) and scale-level content validity index based on universal agreement (S-CVI/UA, 0.85) exceeded the threshold level of 80%. Conclusion: Expert consensus on the educational bundle content was reached using the Delphi method. Further work is required to evaluate its effect in real-world out-of-hospital cardiac arrest calls.

BACKGROUND:Despite declining over the past three decades, unintentional drownings still account for an estimated 236 000 annual deaths worldwide. Susceptibility persists amongst demographic groups and is influenced by sex, age, and socio-economic status, emphasizing the need for targeted interventions. Due to rapidly evolving population dynamics, particularly within Europe, there is a further responsibility to understand the impact of ethnicity on the risks of drowning to guide prevention. METHODS:We conducted a national population-based retrospective study using data from the Swedish National Board of Forensic Medicine and Statistics Sweden for the years 2002 to 2021. The analysis includes variables such as age, sex, presence of alcohol and narcotics as well as activity undertaken at the time of drowning and type of water body. Furthermore, we considered ethnicity to identify subpopulations at greater risks. RESULTS:Results revealed a plateau in unintentional drowning rates in Sweden since 2012, despite an overall decrease from 2002 to 2021. Findings confirm the trend that males are overrepresented within drowning statistics across all age groups, and that individuals aged > 50 constitute over half of all unintentional drownings. Men aged between 40-69 years boating, and individuals of non-Swedish origin, particularly those < 20 years of age, face a notably greater risk of drowning, underscoring the need for subpopulation-targeted prevention strategies. CONCLUSION:The ten-year plateau in unintentional drowning signals the need for an official national prevention strategy with annual evaluations. Suggestions also include improved parental supervision of children, further avoidance of alcohol while swimming and boating, as well as targeted swimming lessons and water competency training for individuals of non-Swedish origin.

Download This Paper Open PDF in Browser Add Paper to My Library Share: Permalink Using these links will ensure access to this page indefinitely Copy URL Copy DOI

Importance: Out-of-hospital cardiac arrest (OHCA) is a leading cause of morbidity and mortality in the US and Europe (∼600,000 incident events annually) and around the world (∼3.8 million). With every minute that passes without cardiopulmonary resuscitation or defibrillation, the probability of survival decreases by 10%. Preliminary studies suggest that uncrewed aircraft systems, also known as drones, can deliver automated external defibrillators (AEDs) to OHCA victims faster than ground transport and potentially save lives. Objective: To date, the United States (US), Sweden, and Canada have made significant contributions to the knowledge base regarding AED-equipped drones. The purpose of this Special Communication is to explore the challenges and facilitators impacting the progress of AED-equipped drone integration into emergency medicine research and applications in the US, Sweden, and Canada. We also explore opportunities to propel this innovative and important research forward. Evidence review: In this narrative review, we summarize the AED-drone research to date from the US, Sweden, and Canada, including the first drone-assisted delivery of an AED to an OHCA. Further, we compare the research environment, emergency medical systems, and aviation regulatory environment in each country as they apply to OHCA, AEDs, and drones. Finally, we provide recommendations for advancing research and implementation of AED-drone technology into emergency care. Findings: The rates that drone technologies have been integrated into both research and real-life emergency care in each country varies considerably. Based on current research, there is significant potential in incorporating AED-equipped drones into the chain of survival for OHCA emergency response. Comparing the different environments and systems in each country revealed ways that each can serve as a facilitator or barrier to future AED-drone research. Conclusions and relevance: The US, Sweden, and Canada each offers different challenges and opportunities in this field of research. Together, the international community can learn from one another to optimize integration of AED-equipped drones into emergency systems of care.

Importance:Smartphone dispatch of volunteer responders to nearby out-of-hospital cardiac arrests (OHCAs) has emerged in several emergency medical services, but no randomized clinical trials have evaluated the effect on bystander use of automated external defibrillators (AEDs).Objective:To evaluate if bystander AED use could be increased by smartphone-aided dispatch of lay volunteer responders with instructions to collect nearby AEDs compared with instructions to go directly to patients with OHCAs to start cardiopulmonary resuscitation (CPR).Design, Setting, and Participants:This randomized clinical trial assessed a system for smartphone dispatch of volunteer responders to individuals experiencing OHCAs that was triggered at emergency dispatch centers in response to suspected OHCAs and randomized 1:1. The study was conducted in 2 main Swedish regions: Stockholm and Västra Götaland between December 2018 and January 2020. At study start, there were 3123 AEDs in Stockholm and 3195 in Västra Götaland and 24 493 volunteer responders in Stockholm and 19 117 in Västra Götaland. All OHCAs in which the volunteer responder system was activated by dispatchers were included. Excluded were patients with no OHCAs, those with OHCAs not treated by the emergency medical services, and those with OHCAs witnessed by the emergency medical services.Interventions:Volunteer responders were alerted through the volunteer responder system smartphone application and received map-aided instructions to retrieve nearest available public AEDs on their way to the OHCAs. The control arm included volunteer responders who were instructed to go directly to the OHCAs to perform CPR.Main Outcomes and Measures:Overall bystander AED attachment, including those attached by volunteer responders and lay volunteers who did not use the smartphone application.Results:Volunteer responders were activated for 947 patients with OHCAs. Of those, 461 were randomized to the intervention group (median [IQR] age of patients, 73 [61-81] years; 295 male patients [65.3%]) and 486 were randomized to the control group (median [IQR] age of patients, 73 [63-82] years; 312 male patients [65.3%]). Primary outcome of AED attachment occurred in 61 patients (13.2%) in the intervention arm vs 46 patients (9.5%) in the control arm (difference, 3.8% [95% CI, -0.3% to 7.9%]; P = .08). The majority of AEDs were attached by lay volunteers who were not using the smartphone application (37 in intervention arm, 28 in control). There were no significant differences in secondary outcomes. Among the volunteer responders using the application, crossover was 11% and compliance to instructions was 31%. Volunteer responders attached 38% (41 of 107) of all AEDs and provided 45% (16 of 36) of all defibrillations and 43% (293 of 666) of all CPR.Conclusions and Relevance:In this study, smartphone dispatch of volunteer responders to OHCAs to retrieve nearby AEDs vs instructions to directly perform CPR did not significantly increase volunteer AED use. High baseline AED attachement rate and crossover may explain why the difference was not significant.Trial Registration:ClinicalTrials.gov Identifier: NCT02992873.