Introduction Cardiac arrest registries can benchmark, enhance quality of care and provide data for research. Key stakeholders from Emergency Medical Communication Centre (EMCC), Emergency Medical Services (EMS), In-Hospital Care Providers (IHCP) and Recovery and Rehabilitation Providers (RRP) have different perspectives, and registry results and patient cohorts should be tailored to facilitate benchmarking, quality improvement projects and research in all sections of the chain of survival. In this paper, we describe different cohorts of interest, exemplified by data from the Norwegian Cardiac Arrest Registry (NorCAR). Method Data from NorCAR for patients registered in 2022 is presented as descriptive statistics. Results The patient cohort with treatment initiated by EMCC comprised 3591 patients (67/100,000 inhabitants). EMS attended 4150 patients with confirmed cardiac arrest (77/100,000 inhabitants) and started cardiopulmonary resuscitation (CPR) in 3083 patients (57/100,000 inhabitants). The patient cohort eligible for treatment by IHCP consists of 1114 patients admitted to hospital alive or with ongoing CPR, along with 1230 in-hospital cardiac arrest cases. The cohort eligible for rehabilitation and follow-up consists of 1227 patients who were alive 24 h after cardiac arrest, 705 out-of-hospital cardiac arrests and 522 in-hospital cardiac arrests. Conclusion It is essential to clearly define the cohort of interest when engaging with different stakeholders and to provide data that facilitates quality improvement projects in all areas of the chain of survival. We recommend defining several subgroups of cardiac arrest patients to accommodate benchmarking, quality improvement projects and research relevant for all stakeholders involved in resuscitation and care of cardiac arrest patients.

Introduction: Self-perceived health status data is usually collected using patient-reported outcome measures. Information from the patients' perspective is one of the important components in planning person-centred care. The study aimed to compare EQ-5D-5L in survivors after out -ofhospital cardiac arrest (OHCA) with data for Norwegian population controls. Secondary aim included comparing characteristics of respondents and non-respondents from the OHCA population. Methods: In this cross-sectional survey, 714 OHCA survivors received an electronic EQ-5D-5L questionnaire 3-6 months following OHCA. EQ-5D5L assesses for five dimensions of health (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with five-point descriptive scales and overall health on a visual analogue scale from 0 (worst) to 100 (best) (EQ VAS). Results are used to calculate the EQ index ranging from -0.59 (worst) to 1 (best). Patient responses were matched for age and sex with existing data from controls, collected through a postal survey (response rate 26%), and compared with Chi-square tests or t-tests as appropriate. Results: Of 784 OHCA survivors, 714 received the EQ-5D-5L, and 445 (62%) responded. Respondents had higher rates of shockable first rhythm and better cerebral performance category scores than the non-respondents. OHCA survivors reported poorer health compared to controls as assessed by EQ-5D-5L dimensions, the EQ index (0.76 +/- 0.24 vs 0.82 +/- 0.18), and EQ VAS (69 +/- 21 vs 79 +/- 17), except for the pain/discomfort dimension. Conclusions: Norwegian OHCA survivors reported poorer health than the general population as assessed by the EQ-5D-5L. PROMs use in this population can be used to inform follow-up and health care delivery.

Aim of the studyCardiac arrest research has not received as much scientific attention as research on other topics. Here, we aimed to identify cardiac arrest research barriers from the perspective of an international group of early career researchers.MethodsAttendees of the 2022 international masterclass on cardiac arrest registry research accompanied the Global Out-of-Hospital Cardiac Arrest Registry collaborative meeting in Utstein, Norway, and used an adapted hybrid nominal group technique to obtain a diverse and comprehensive perspective. Barriers were identified using a web-based questionnaire and discussed and ranked during an in-person follow-up meeting. After each response was discussed and clarified, barriers were categorized and ranked over two rounds. Each participant scored these from 1 (least significant) to 5 (most significant).ResultsNine participants generated 36 responses, forming seven overall categories of cardiac arrest research barriers. “Allocated research time” was ranked first in both rounds. “Scientific environment”, including appropriate mentorship and support systems, ranked second in the final ranking. “Resources”, including funding and infrastructure, ranked third. “Access to and availability of cardiac arrest research data” was the fourth-ranked barrier. This included data from the cardiac arrest registries, medical devices, and clinical studies. Finally, “uniqueness” was the fifth-ranked barrier. This included ethical issues, patient recruitment challenges, and unique characteristics of cardiac arrest.ConclusionBy identifying cardiac arrest research barriers and suggesting solutions, this study may act as a tool for stakeholders to focus on helping early career researchers overcome these barriers, thus paving the road for future research.

Aim: Children constitute an important and distinct subgroup of out -of -hospital cardiac arrest (OHCA) patients. This population -based cohort study aims to establish current age -specific population incidence, precipitating causes, circumstances, and outcome of paediatric OHCA, to guide a focused approach to prevention and intervention to improve outcomes. Methods: Data from the national Norwegian Cardiac Arrest Registry was extracted for the six -year period 2016-21 for persons aged <18 years. We present descriptive statistics for the population, resuscitation events, presumed causes, treatment, and outcomes, alongside age -specific incidence and total paediatric mortality rates. Results: Three hundred and eight children were included. The incidence of OHCA was 4.6 per 100 000 child -years and markedly higher in children <1 year at 20.9 child -years. Leading causes were choking, cardiac and respiratory disease, and sudden infant death syndrome. Overall, 21% survived to 30 days and 18% to one year. Conclusion: A registry -based approach enabled this study to delineate the characteristics and trajectories of OHCA events in a national cohort of children. Precipitating causes of paediatric OHCA are diverse compared to adults. Infants aged <1 year are at particularly high risk. Mortality is high, albeit lower than for adults in Norway. A rational community approach to prevention and treatment may focus on general infant care, immediate first aid by caretakers, and identification of vulnerable children by primary health providers. Cardiac arrest registries are a key source of knowledge essential for quality improvement and research into cardiac arrest in childhood.

Aim: Compare lung injury and hemodynamic effects in synchronized ventilations (between two chest compressions) vs. unsynchronized ventilations during cardiopulmonary resuscitation (CPR) in a porcine model of cardiac arrest.Methods: Twenty pigs were randomized to either synchronized or unsynchronized group. Ventricular fibrillation was induced electrically and left for 1.5 minutes. Four minutes of basic chest compression:ventilation (30:2) CPR was followed by eight minutes of either synchronized or unsynchronized ventilations (10/min) during continuous compressions before defibrillation was attempted. Aortic, right atrial and intracerebral pressures, carotid and cerebral blood flow and cardiac output were measured. Airway monitoring included capnography and respiratory function monitor. Macro and microscopic lung injuries were assessed post-mortem.Results: There were no significant differences between groups in any of the measured hemodynamic variables or inspiration time (0.4 vs. 1.0 s, p = 0.05). The synchronized ventilation group had lower median peak inspiratory airway pressure (57 vs. 94 cm H2O, p < 0.001), lower minute ventilation (3.7 vs. 9.4 l min-1, p < 0.001), lower pH (7.31 vs. 7.53, p < 0.001), higher pCO2 (5.2 vs. 2.5 kPa, p < 0.001) and lower pO2 (31.6 vs. 54.7 kPa, p < 0.001) compared to the unsynchronized group after 12 minutes of CPR. There was significant lung injury after CPR in both synchronized and unsynchronized groups.Conclusion: Synchronized and unsynchronized ventilations resulted in similar hemodynamics and lung injury during continuous mechanical compressions of pigs in cardiac arrest. Animals that received unsynchronized ventilations with one second inspiration time at a rate of ten ventilations per minute were hyperventilated and hyperoxygenated. Institutional protocol number: FOTS, id 6948.

Patients undergoing cardiopulmonary ressuscitation (CPR) may respond through rhythm transitions between different rhythms ventricular fibrillation (VF), ventricular tachycardia (VT), asystole (AS), pulseless electrical activity (PEA) and pulse generating rhythm (PR). Rhythm recognition is crucial to address adequate resuscitation efforts, and in this study we applied a deep neural network to classify ECG rhythms during cardiac arrest. Artifact-free four second segments were extracted from 100 patients in out-of-hospital cardiac arrest. A convolutional neural network (CNN) was trained to discriminate between five cardiac arrest rhytm types. Experiments were conducted with increasing number of layers. For each model, training was repeated 10 times to explore variations in the results. A five layer network provided the best performance with an accuracy of 80. 3 (78.1,81.3)% (median(25th, 75th quartiles)). We have proposed a deep learning approach to automatically recognise five cardiac arrest rhythms common during resuscitation.

Aim: We wanted to assess the implementation and use of a supraglottic airway (SGA) for on-call firefighter first responders in out-of-hospital cardiac arrest.Methods: We trained 502 firefighter first responders, located at 35 fire stations in the South-East of Norway, in the use of SGA during cardiopul-monary resuscitation in adult out-of-hospital cardiac arrest. Training consisted of 45 minutes of theoretical and practical training in small groups. Primary outcome was successful ventilation with SGA assessed by both firefighter first responders and first paramedic arriving on-scene. Secondary outcomes included time expenditure and complications related to the procedure, evaluation of the training, and descriptive characteristics of the out-of-hospital cardiac arrest cases.Results: An SGA was used by firefighter first responders in 23 out-of-hospital cardiac arrests, and successful ventilation was achieved in 20 (87%) cases. Air-leak was described in the three unsuccessful cases. The median procedural time was 30 seconds (IQR = 15-40), with no observed pro-cedural complications. Firefighter first responders arrived in median time 9 minutes (IQR = 6-10 min) before the ambulance. They performed chest compressions on all patients and 6 (26%) of the patients received shock with semi-automatic external defibrillator. After training, all participants were able to successfully ventilate a manikin with the SGA. The cost of the SGA equipment for all fire stations was 3955 GBP.Conclusion: Implementation of an SGA for firefighter first responders in out-of-hospital cardiac arrest management seems feasible, safe and can be introduced with limited amount of training and limited use of resources.

AIM:Bystander cardiopulmonary resuscitation (CPR) significantly increases the survival rate after out-of-hospital cardiac arrest. Using population-based registries, we investigated the impact of lockdown due to Covid-19 on the provision of bystander CPR, taking background changes over time into consideration. METHODS:Using a registry network, we invited all registries capable of delivering data from 1. January 2017 to 31. December 2020 to participate in this study. We used negative binominal regression for the analysis of the overall results. We also calculated the rates for bystander CPR. For every participating registry, we analysed the incidence per 100000 inhabitants of bystander CPR and EMS-treated patients using Poisson regression, including time trends. RESULTS:Twenty-six established OHCA registries reported 742 923 cardiac arrest patients over a four-year period covering 1.3 billion person-years. We found large variations in the reported incidence between and within continents. There was an increase in the incidence of bystander CPR of almost 5% per year. The lockdown in March/April 2020 did not impact this trend. The increase in the rate of bystander CPR was also seen when analysing data on a continental level. We found large variations in incidence of bystander CPR before and after lockdown when analysing data on a registry level. CONCLUSION:There was a steady increase in bystander CPR from 2017 to 2020, not associated with an increase in the number of ambulance-treated cardiac arrest patients. We did not find an association between lockdown and bystanders' willingness to start CPR before ambulance arrival, but we found inconsistent patterns of changes between registries.

Aim: To compare health-related quality of life (HRQoL) in young survivors of out-of-hospital cardiac arrest (OHCA) in Norway with an age and sex-matched reference population and to assess the associations between exercise volume prior to OHCA and HRQoL after. Methods: We present data from survivors aged 18-50 years registered with OHCA in the Norwegian Cardiac Arrest Registry between January 1st 2015 and December 31st 2017. Survivors were invited to answer two questionnaires; (1) the Short Form 36 (SF-36) Health Survey Version 1, and (2) about exercise habits prior to OHCA. Respondents were randomly matched 1:1 for age and sex with a reference population (data were available from the Norwegian Centre for Research Data). Results: Of the 175 survivors invited, 95 (54%) responded, median age was 44 (range 35-48) years, 26 (27%) females. Valid results for SF-36 were available for 91 survivors, of whom 87 reported pre-OHCA exercise-volume. Prior to OHCA, 21 did no regular exercise, 44 exercised 1-4 hours/week and 22 exercised >5 hours/week. Compared to the reference population survivors had significantly (p < 0.01) poorer SF-36 scores for scales relating to physical-and mental health. SF-36 scale scores were similar in survivors who did and did not exercise regularly. Within the regular exercisers, survivors reporting >5 hours of exercise/week had better SF-36 scores than those exercising less. Conclusion: Poorer HRQoL in survivors compared to the reference population should prompt us to explore how treatment and rehabilitation could be improved and adapted. More exercise before OHCA favoured better HRQoL after, which aligns well with the recognised positive association between HRQoL and physical activity in general.

Introduction: Regular exercise is associated with reduced risk of cardiovascular disease. Paradoxically, an increased risk of sudden cardiac arrest (SCA) is documented during or immediately after exercise and in athletes compared to the nonathletic population. Our objective was to identify, through multiple sources, the total number of exercise-related versus non-exercise-related SCA in the young population in Norway. Methods: We collected primary data from the prospective Norwegian Cardiac Arrest Registry (NorCAR) for all patients aged 12-50 suffering SCA of presumed cardiac cause from 2015 to 2017. We collected secondary data about prior physical activity and the SCA, through questionnaires. We searched media reports for SCA incidents in sports. Exercise-related SCA is defined as SCA during or < 1 h after exercise. Results: Overall, 624 patients, median age 43 years, were included from NorCAR. Two thirds (393) replied to the study invitation, of whom 236 answered the questionnaires: 95 survivors and 141 next of kin. The media search resulted in 18 relevant hits. With a multiple source approach, we identified 63 cases of exercise--related SCA, equivalent to an incidence of 0.8/100 000 person-years, versus 7.8/100 000 person-years of non-exercise-related SCA. Among those who answered (n = 236), almost two thirds (59%) exercised regularly, most commonly (45%) 1-4 h/week. Endurance exercise (38%) was the most prevalent type of regular exercise and the most common activity during exercise-related SCA (53%). Conclusion: The burden of exercise--related SCA was low (0.8 per 100 000 person-years) and ten times lower than non-exercise-related SCA in the young population in Norway.

Background: Both skeletal and visceral injuries are reported after cardiopulmonary resuscitation (CPR). This subgroup analysis of a randomized clinical study describes/compares autopsy documented injury patterns caused by two mechanical, piston-based chest compression devices: stan-dard LUCAS (R) 2 (control) and LUCAS (R) 2 with active decompression (AD, intervention) in non-survivors with out-of-hospital cardiac arrest (CA). Method: We compared injuries documented by autopsies (medical/forensic) after control and intervention CPR based on written relatives consent to use patients' data. The pathologists were blinded for the device used. The cause of CA and injuries reported were based on a prespecified study autopsy template. We used Pearson's chi-squared test and logistic regression analysis with an alpha level of 0.05. Results: 221 patients were included in the main study (April 2015-April 2017) and 207 did not survive. Of these, 114 (55%, 64 control and 50 inter-vention) underwent medical (N = 73) or forensic (N = 41) autopsy. The cause of CA was cardiac 53%, respiratory 17%, overdose/intoxication 14%, ruptured aorta 10%, neurological 1%, and other 5%. There were no differences between control and intervention in the incidence of rib fractures (67% vs 72%; p-value = 0.58), or sternal fractures (44% vs 48%; p-value = 0.65), respectively. The most frequent non-skeletal complication was bleeding (26% of all patients) and intrathoracic was the most common location. Ten of the 114 patients had internal organ injuries, where lungs were most affected. Conclusion: In non-survivors of OHCA patients, the most frequent cause of cardiac arrest was cardiogenic. Skeletal and non-skeletal fractures/ injuries were found in both control and intervention groups. Bleeding was the most common non-skeletal complication. Internal organ injuries were rare.

Background: Perceptions about expected outcome after out-of-hospital cardiac arrest (OHCA) influence treatment decisions, and there is a need for updated evidence about outcomes for the elderly. Method: We conducted a cross-sectional study of cases reported to the Norwegian Cardiac Arrest Registry from 2015 through 2021 of patients 60 years and older, suffering cardiac arrest in healthcare institutions or at home. We examined reasons for emergency medical service (EMS) with-holding or withdrawing resuscitation. We compared survival and neurological outcome for EMS-treated patients and explored factors associated with survival using multivariate logistic regression.Result: We included 12,191 cases and the EMS started resuscitation in 10,340 (85%). The incidence per capita of OHCA the EMS were alerted to was 267/100,000 in healthcare institutions and 134/100,000 at home. Resuscitation was most frequently withdrawn due to medical history (n = 1251). In healthcare institutions, 72 of 1503 (4.8%) patients survived to 30 days compared to 752 of 8837 (8.5%) at home (P <.001). We found survivors in all age cohorts both in healthcare institutions and at home, and most of the 824 survivors had a good neurological outcome with a Cere-bral Performance Category <2 (88%).Conclusion: Medical history was the most frequent reason for EMS not to start or continue resuscitation, indicating a need for a discussion about, and documentation of, advance directives in this age group. When EMS attempted resuscitation, most survivors had a good neurological outcome, both in healthcare institutions and at home.

Aim This work provides an epidemiological overview of out-of-hospital cardiac arrest (OHCA) in children in Germany between 2007 and 2021. We wanted to identify modifiable factors associated with survival. Methods Data from the German Resuscitation Registry (GRR) were used, and we included patients registered between 1st January 2007 and 31st December 2021. We included children aged between > 7 days and 17 years, where cardiopulmonary resuscitation (CPR) was started, and treatment was continued by emergency medical services (EMS). Incidences and descriptive analyses are presented for the overall cohort and each age group. Multivariate binary logistic regression was performed on the whole cohort to determine the influence of (1) CPR with/without ventilation started by bystander, (2) OHCA witnessed status and (3) night-time on the outcome hospital admission with return of spontaneous circulation (ROSC). Results OHCA in children aged < 1 year had the highest incidence of the same age group, with 23.42 per 100 000. Overall, hypoxia was the leading presumed cause of OHCA, whereas trauma and drowning accounted for a high proportion in children aged > 1 year. Bystander-witnessed OHCA and bystander CPR rate were highest in children aged 1–4 years, with 43.9% and 62.3%, respectively. In reference to EMS-started CPR, bystander CPR with ventilation were associated with an increased odds ratio for ROSC at hospital admission after adjusting for age, sex, year of OHCA and location of OHCA. Conclusion This study provides an epidemiological overview of OHCA in children in Germany and identifies bystander CPR with ventilation as one primary factor for survival. Trial registrations German Clinical Trial Register: DRKS00030989, December 28th 2022. Graphical Abstract