Andreas Claesson

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

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 programs 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 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 dispatch of regular emergency medical services (EMS). The aim is to investigate if trained CFRs can successfully recognize 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 September 1st, 2025, and August 31st, 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. Conclusion: Safe, early and effective management of opioid overdoses by trained CFRs prior to EMS arrival may reduce morbidity and mortality among people who use opioids. Findings from the current trial may contribute to further knowledge on how to implement and improve CFR systems for opioid overdoses globally. ClinicalTrials.gov-ID: NCT07079241 . Article Summary: Strengths and limitations of this study: - The RESPONDER trial introduces a novel community first responder system for time-critical opioid overdose reversal in addition to out-of-hospital cardiac arrest. - The trial aims to enhance access to naloxone and raise community awareness, improving the likelihood of early and potentially life-saving overdose reversal. - A study-specific course introduces a novel naloxone algorithm which has been developed by expertise in the fields of resuscitation, First Aid and opioid use disorder. - The study group consists of researchers and clinicians with a broad range of expertise concerning opioid overdose management, substance use disorders, First Aid education, emergency medical services, emergency medical dispatch centre operations and community first responder systems, adding several in-depth perspectives to this community first responder model. - A limitation may be that overdose events unreported to emergency dispatch centres will not reach the trial’s community first responders.

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.

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.

Background: In animal models, early initiation of therapeutic cooling, intra-arrest, or restored circulation has been shown to be neuroprotective shortly after cardiac arrest. We aimed to assess the feasibility and cooling efficacy of transnasal evaporative cooling, initiated as early as possible after hospital arrival in patients randomized to cooling in the TTM2 trial. Methods: This study took the form of a single-center (Södersjukhuset, Stockholm) substudy of the TTM2 trial (NCT02908308) comparing target temperature management (TTM) to 33 °C versus normothermia in OHCA. In patients randomized to TTM33 °C, transnasal evaporative cooling was applied as fast as possible. The primary objectives were the feasibility aspects of initiating cooling in different hospital locations (i.e., in the emergency department, coronary cathlab, intensive care unit (ICU), and during intrahospital transport) and its effectiveness (i.e., time to reach target temperature). Transnasal cooling was continued for two hours or until patients reached a core temperature of <34 °C. Cooling intervals were compared to participants at the same site who were randomized to hypothermia and treated at 33 °C but who for different reasons did not receive transnasal evaporative cooling. Results: From October 2018 to January 2020, 32 patients were recruited, of which 17 were randomized to the TTM33. Among them, 10 patients (8 men, median age 69 years) received transnasal evaporative cooling prior to surface systemic cooling in the ICU. In three patients, cooling was started in the emergency department; in two patients, it was started in the coronary cathlab, and in five patients, it was started in the ICU, of which three patients were subsequently transported to the coronary cathlab or to perform a CT scan. The median time to initiate transnasal cooling from randomization was 9 min (range: 5 to 39 min). The median time from randomization to a core body temperature of 34 °C was 120 min (range 60 to 334) compared to 178 min among those in the TTM33 group that did not receive TNEC and to 33 °C 230 min (range: 152 to 351) vs. 276 min (range: 150 to 546). No feasibility or technical issues were reported. No adverse events occurred besides minor nosebleeds. Conclusions: The early induction of transnasal cooling in out-of-hospital cardiac arrest patients was feasible to initiate in the emergency department, coronary cathlab, ICU, and during intrahospital transport. Time to target temperature was shortened compared to standard cooling.

To study aetiologies of in-hospital cardiac arrests (IHCAs) and their association with 30-day survival. Observational study with data from national registries. Specific aetiologies (n = 22) of IHCA patients between April 2018 and December 2020 were categorized into cardiac vs. non-cardiac and six main aetiology categories: myocardial ischemia, other cardiac causes, pulmonary causes, infection, haemorrhage, and other non-cardiac causes. Main endpoints were proportions in each aetiology, 30-day survival, and favourable neurological outcome (Cerebral Performance Category scale 1–2) at discharge. Among, 4320 included IHCA patients (median age 74 years, 63.1% were men), approximate 50% had cardiac causes with a 30-day survival of 48.4% compared to 18.7% among non-cardiac causes (P < 0.001). The proportion in each category were: myocardial ischemia 29.9%, pulmonary 21.4%, other cardiac causes 19.6%, other non-cardiac causes 11.6%, infection 9%, and haemorrhage 8.5%. The odds ratio (OR) for 30-day survival compared to myocardial ischemia for each category were: other cardiac causes OR 1.48 (CI 1.24–1.76); pulmonary causes OR 0.36 (CI 0.3–0.44); infection OR 0.25 (CI 0.18–0.33); haemorrhage OR 0.22 (CI 0.16–0.3); and other non-cardiac causes OR 0.56 (CI 0.45–0.69). IHCA caused by myocardial ischemia had the best favourable neurological outcome while those caused by infection had the lowest OR 0.06 (CI 0.03–0.13). In this nationwide observational study, aetiologies with cardiac and non-cardiac causes of IHCA were evenly distributed. IHCA caused by myocardial ischemia and other cardiac causes had the strongest associations with 30-day survival and neurological outcome.