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Here we report the results of a study on the association between drug delivery via intravenous route or intraosseous route in out-of-hospital cardiac arrest. Intraosseous drug delivery is considered an alternative option in resuscitation if intravenous access is difficult or impossible. Intraosseous uptake of drugs may, however, be compromised. We have performed a retrospective cohort study of all Danish patients with out-of-hospital cardiac arrest in the years 2016–2020 to investigate whether mortality is associated with the route of drug delivery. Outcome was 30-day mortality, death at the scene, no prehospital return of spontaneous circulation, and 7- and 90-days mortality. 17,250 patients had out-of-hospital cardiac arrest. 6243 patients received no treatment and were excluded. 1908 patients had sustained return of spontaneous circulation before access to the vascular bed was obtained. 2061 patients were unidentified, and 286 cases were erroneously registered. Thus, this report consist of results from 6752 patients. Drug delivery by intraosseous route is associated with increased OR of: No spontaneous circulation at any time (OR 1.51), Death at 7 days (OR 1.94), 30 days (2.02), and 90 days (OR 2.29). Intraosseous drug delivery in out-of-hospital cardiac arrest is associated with overall poorer outcomes than intravenous drug delivery. [ABSTRACT FROM AUTHOR]

Background: Prehospital emergency physicians have to navigate complex decision-making in out-of-hospital cardiac arrest (OHCA) treatment that includes ethical considerations. This study explores Danish prehospital physicians' experiences of ethical issues influencing their decision-making during OHCA. Methods: We conducted a multisite ethnographic study. Through convenience sampling, we included 17 individual interviews with prehospital physicians and performed 22 structured observations on the actions of the prehospital personnel during OHCAs. We collected data during more than 800 observation hours in the Danish prehospital setting between December 2019 and April 2022. Data were analysed with thematic analysis. Results: All physicians experienced ethical considerations that influenced their decision-making in a complex interrelated process. We identified three overarching themes in the ethical considerations: Expectations towards patient prognosis and expectations from relatives, bystanders, and colleagues involved in the cardiac arrest; the values and beliefs of the physician and values and beliefs of others involved in the cardiac arrest treatment; and dilemmas encountered in decision-making such as conflicting values. Conclusion: This extensive qualitative study provides an in-depth look at aspects of ethical considerations in decision-making in prehospital resuscitation and found aspects of ethical decision-making that could be harmful to both physicians and patients, such as difficulties in handling advance directives and potential unequal outcomes of the decision-making. The results call for multifaceted interventions on a wider societal level with a focus on advance care planning, education of patients and relatives, and interventions towards prehospital clinicians for a better understanding and awareness of ethical aspects of decision-making. [ABSTRACT FROM AUTHOR]

Background: Cardiac arrest following trauma is a leading cause of death, mandating urgent treatment. This study aimed to investigate and compare the incidence, prognostic factors, and survival between patients suffering from traumatic cardiac arrest (TCA) and non-traumatic cardiac arrest (non-TCA). Methods: This cohort study included all patients suffering from out-of-hospital cardiac arrest in Denmark between 2016 and 2021. TCAs were identified in the prehospital medical record and linked to the out-of-hospital cardiac arrest registry. Descriptive and multivariable analyses were performed with 30-day survival as the primary outcome. Results: A total of 30,215 patients with out-of-hospital cardiac arrests were included. Among those, 984 (3.3%) were TCA. TCA patients were younger and predominantly male (77.5% vs 63.6%, p = < 0.01) compared to non-TCA patients. Return of spontaneous circulation occurred in 27.3% of cases vs 32.3% in non-TCA patients, p < 0.01, and 30-day survival was 7.3% vs 14.2%, p < 0.01. An initial shockable rhythm was associated with increased survival (aOR = 11.45, 95% CI [6.24 – 21.24] in TCA patients. When comparing TCA with non-TCA other trauma and penetrating trauma were associated with lower survival (aOR: 0.2, 95% CI [0.02–0.54] and aOR: 0.1, 95% CI [0.03 – 0.31], respectively. Non-TCA was associated with an aOR: 3.47, 95% CI [2.53 – 4,91]. Conclusion: Survival from TCA is lower than in non-TCA. TCA has different predictors of outcome compared to non-TCA, illustrating the differences regarding the aetiologies of cardiac arrest. Presenting with an initial shockable cardiac rhythm might be associated with a favourable outcome in TCA. [ABSTRACT FROM AUTHOR]

Background: Substantial variation in survival following out‐of‐hospital cardiac arrest (OHCA) is described both internationally and nationally. The Utstein factors account for half of the variation, but the remaining is not fully understood. Local regulations or guidelines concerning the withholding and termination of resuscitation may influence the reporting of cardiac arrests when comparing outcomes between different Emergency Medical Service systems. Method: We have developed an online cross‐sectional mixed‐methods explanatory design survey aimed at describing the international and national variations in the initiation, the termination of resuscitation, and the refraining from resuscitation of adult patients (>18 years of age) suffering from non‐traumatic OHCA. The respondents will be national experts and the questionnaire will be distributed among members of European Prehospital Research Alliance, the International Liaison Committee of Resuscitation, the European Resuscitation Council, and the Resuscitation Academy. Each invited country will have to identify at least two national experts with special expertise in prehospital resuscitation practices. We exclude countries with less than two respondents. Results: The survey will provide both quantitative and qualitative data. Quantitative data will be presented as frequencies and proportions. Qualitative data will be analyzed using content analysis. Conclusion: This survey could be of importance in understanding the multiple factors leading to the substantial variation in survival found following OHCA. Furthermore, the interpretation of future studies on OHCA from different settings may be improved to further increase survival following OHCA. [ABSTRACT FROM AUTHOR]

Aim of the Database: The aim of the Danish Cardiac Arrest Registry is to monitor the quality of prehospital cardiac arrest treatment, evaluate initiatives regarding prehospital treatment of cardiac arrest, and facilitate research. Study Population: All patients with prehospital cardiac arrest in Denmark treated by the emergency medical services in whom resuscitation or defibrillation has been attempted. Main Variables: The Danish Cardiac Arrest Register records descriptive and qualitative variables as outlined in the "Utstein" template for reporting out-of-hospital-cardiac arrest. Main variables include whether the case was witnessed, whether the cardiac arrest was electrocardiographically monitored, the timing of cardiopulmonary resuscitation, and the timing of the first analysis of the cardiac rhythm. The outcome measures are the status of the patient at handover to the hospital, return of spontaneous circulation, and 30-day survival after event. Database Status: The Danish Cardiac Arrest Registry was established in June 2001, and all Danish emergency medical services are reporting to the database. Conclusion: The Danish Cardiac Arrest Registry is among the oldest Danish national clinical registries, with a high quality of clinical data and coverage. This registry provides the prerequisite for all research on out-of-hospital cardiac arrest research in Denmark and is essential for monitoring and improving the quality of care for patients suffering from out-of-hospital cardiac arrest. [ABSTRACT FROM AUTHOR]

Background: Decision-making in out-of-hospital cardiac arrest should ideally include clinical and ethical factors. Little is known about the extent of ethical considerations and their influence on prehospital resuscitation. We aimed to determine the transparency in medical records regarding decision-making in prehospital resuscitation with a specific focus on ethically relevant information and consideration in resuscitation providers' documentation.Methods: This was a Danish nationwide retrospective observational study of out-of-hospital cardiac arrests from 2016 through 2018. After an initial screening using broadly defined inclusion criteria, two experienced philosophers performed a qualitative content analysis of the included medical records according to a preliminary codebook. We identified ethically relevant content in free-text fields and categorised the information according to Beauchamp and Childress' four basic bioethical principles: autonomy, non-maleficence, beneficence, and justice.Results: Of 16,495 medical records, we identified 759 (4.6%) with potentially relevant information; 710 records (4.3%) contained ethically relevant information, whereas 49 did not. In general, the documentation was vague and unclear. We identified four kinds of ethically relevant information: patients' wishes and perspectives on life; relatives' wishes and perspectives on patients' life; healthcare professionals' opinions and perspectives on resuscitation; and do-not-resuscitate orders. We identified some "best practice" examples that included all perspectives of decision-making.Conclusions: There is sparse and unclear evidence on ethically relevant information in the medical records documenting resuscitation after out-of-hospital cardiac arrests. However, the "best practice" examples show that providing sufficient documentation of decision-making is, in fact, feasible. To ensure transparency surrounding prehospital decisions in cardiac arrests, we believe that it is necessary to ensure more systematic documentation of decision-making in prehospital resuscitation. [ABSTRACT FROM AUTHOR]

Background Early identification of warning symptoms among out-of-hospital cardiac arrest (OHCA) patients remains challenging. Thus, we examined the registered prodromal symptoms of patients who called medical helpline services within 30-days before OHCA. Methods Patients unwitnessed by emergency medical services (EMS) aged ≥18 years during their OHCA were identified from the Danish Cardiac Arrest Registry (2014–2018) and linked to phone records from the 24-h emergency helpline (1−1−2) and out-of-hours medical helpline (1813-Medical Helpline) in Copenhagen before the arrest. The registered symptoms were categorized into chest pain; breathing problems; central nervous system (CNS)-related/unconsciousness; abdominal/back/urinary; psychiatric/addiction; infection/fever; trauma/exposure; and unspecified (diverse from the beforementioned categories). Analyses were divided by the time-period of calls (0-7 days/8-30 days preceding OHCA) and call type (1–1-2/1813-Medical Helpline). Results Of all OHCA patients, 18% (974/5442) called helpline services (males 56%, median age 76 years[Q1-Q3:65–84]). Among these, 816 had 1145 calls with registered symptoms. The most common symptom categories (except for unspecified, 33%) were breathing problems (17%), trauma/exposure (17%), CNS/unconsciousness (15%), abdominal/back/urinary (12%), and chest pain (9%). Most patients (61%) called 1813-Medical Helpline, especially for abdominal/back/urinary (17%). Patients calling 1–1-2 had breathing problems (24%) and CNS/unconsciousness (23%). Nearly half of the patients called within 7 days before their OHCA, and CNS/unconsciousness (19%) was the most registered. The unspecified category remained the most common during both time periods (32%;33%) and call type (24%;39%). Conclusions Among patients who called medical helplines services up to 30-days before their OHCA, besides symptoms being highly varied (unspecified (33%)), breathing problems (17%) were the most registered symptom-specific category. [Display omitted] • Nearly 1 out of 5 patients called the medical helpline services within a month before their cardiac arrest. • Despite prodromal symptoms being highly varied during these calls, breathing problems were the most registered symptom-specific category and nearly twice more common than chest pain. • Almost half of the patients called within the week before their OHCA, where CNS-realted symptoms/unconsciousness was the most registered symptom-specific category. • More patients called the non-emergency number than the emergency number. [ABSTRACT FROM AUTHOR]

Aim: There is limited evidence regarding prodromal symptoms of out-of-hospital cardiac arrest (OHCA). We aimed to describe patient characteristics, prodromal symptoms, and prognosis of patients contacting emergency medical services (EMS) within 24 hours before OHCA.Methods: We identified all OHCA treated by Copenhagen EMS from 2016 through 2018 using the Danish Cardiac Arrest Registry and linked them to emergency calls. We included all pre-arrest calls by patients or bystanders if they were performed 1) within 24 hours before the OHCA call or 2) during the OHCA event for EMS-witnessed OHCA. Calls were reviewed by healthcare professionals using a survey guide.Results: Among 4,071 patients, 481 patients (12 %) had 539 calls within 24 hours prior to OHCA (60 % male, median age 74 years of age). The patient spoke on the phone in 25 % of calls. The most common symptoms were breathing problems (59 %), confusion (23 %), unconsciousness (20 %), chest pain (20 %), and paleness (19 %). Patients with breathing problems compared to chest pain were more likely to be ≤ 75 years of age (55 % versus 35 %), less likely to be male (52 % versus 73 %), have shockable rhythm (10 % versus 38 %), receive bystander defibrillation (6 % versus 19 %) or EMS defibrillation (15 % versus 65 %), achieve return of spontaneous circulation (37 % versus 68 %) and survive 30 days following OHCA (10 % versus 50 %).Conclusion: More than 10% of patients with OHCA had a call to EMS within 24 hours before OHCA. The most common symptom was breathing problems which compared to chest pain had lower 30-day survival. [ABSTRACT FROM AUTHOR]

Background: Regular exercise is known to prevent cardiovascular disorders, but it may also trigger acute cardiac events. This study examined the incidence, prognosis, and outcomes of out-of-hospital cardiac arrest (OHCA) related to exercise in the general population of Denmark.Methods: This retrospective cohort study examined all the OHCAs in the Danish Cardiac Arrest Registry from 2016 to 2019. OHCA related to exercise was identified in a nationwide electronic database and coupled to the patient register. Descriptive statistics were used in combination with a multivariate logistic regression model to assess predefined factors.Results: A total of 20,470 OHCAs were identified, of which 459 (2.2%) were related to exercise. Most were male (75.3%), with a median age of 61 years. Further, 95% of exercise-related OHCA received bystander cardiopulmonary resuscitation, compared to 77.4% in non-exercise-related OHCA (p < 0.001), and 38.3% received defibrillation by bystanders versus 7.5% in the non-exercise group (p < 0.001). Exercise-related OHCAs had a 30-day survival rate of 57.7% compared to 12.6% in the non-exercise group, yielding an adjusted odds ratio of 5.56. The 30-day survival rate of exercise-related subjects aged 15-35 years was 80.0%, compared to 25.0% in the non-exercise group. When comparing sports categories, team sports were associated with the greatest chance of survival (odds ratio of 18.5 versus a non-exercise odds ratio of 0.09).Conclusion: Exercise-related OHCA has a low incidence and is related to a significantly better prognosis when compared to non-exercise OHCA. Furthermore, many patients experiencing exercise-related OHCA received defibrillation and cardiopulmonary resuscitation by bystanders. These findings could help plan and execute campaigns and education. [ABSTRACT FROM AUTHOR]

Background: Bystander-initiated basic life support (BLS) plays an important role in improving survival after out-of-hospital cardiac arrest. In 2009, laws mandating BLS course participation when acquiring a driver's licence were implemented in Denmark. The aim of this study was to characterise Danish BLS course participants.Methods: This study is a Danish, registry-based, follow-up study that examined all Danish BLS course participants from 2016 to 2019. Data concerning BLS course participation were supplied by the major Danish BLS course providers. Socio-economic and healthcare data on all Danish inhabitants were assessed using national registers from Statistics Denmark.Results: Between January 1, 2016, and January 1, 2020, 3.6% of the entire adult population of Denmark attended certified BLS courses annually. Since the implementation of a law mandating BLS course participation when acquiring a driver licence in 2009, approximately 44% of the adult population has participated in a BLS course. BLS course participants were commonly younger and healthier than the general population (mean 31.3 years old vs. 51.3 years old, P < 0.001). Furthermore, law-mandated BLS course participants had a lower disposable income (adjusted OR: 0.23; 95% CI: 0.23-0.23; P < 0.001) and were more likely to live in rural areas (adjusted OR: 0.57; 95% CI: 0.57-0.58; P < 0.001).Conclusion: In Denmark, 3.6% of the entire adult population attend certified courses annually. BLS participants are commonly male, younger, healthier, less likely to have small children in the household, and more likely to live in rural areas. Law-mandated BLS course participation prior to acquiring a driver's licence has been successful in reaching segments of the society that are known to have limited participation. [ABSTRACT FROM AUTHOR]

Foreign body airway obstruction (FBAO) stands as an important contributor to accidental fatalities, yet prompt bystander interventions have been shown to improve survival. This study aimed to evaluate the incidence, interventions, and survival outcomes of patients with out-of-hospital cardiac arrest (OHCA) related to FBAO in comparison to patients with non-FBAO OHCA. In this population-based cohort study, we included all OHCAs in Denmark from 2016 to 2022. Cases related to FBAO were identified and linked to the patient register. Descriptive and multivariable analyses were performed to evaluate prognostic factors potentially influencing survival. A total of 30,926 OHCA patients were included. The incidence rate of FBAO-related OHCA was 0.78 per 100,000 person-years. Among FBAO cases, 24% presented with return of spontaneous circulation upon arrival of the emergency medical services. The 30-day survival rate was higher in FBAO patients (30%) compared to non-FBAO patients (14%). Bystander interventions were recorded in 26% of FBAO cases. However, no statistically significant association between bystander interventions or EMS personnels' use of Magill forceps and survival was shown, aOR 1.47 (95 % CI 0.6–3.6) and aOR 0.88 (95% CI 0.3–2.1). FBAO-related OHCA was rare but has a higher initial survival rate than non-FBAO related OHCA, with a considerable proportion of patients achieving return of spontaneous circulation upon arrival of the emergency medical service personnel. No definitive associations were established between survival and specific interventions performed by bystanders or EMS personnel. These findings highlight the need for further research in this area. [ABSTRACT FROM AUTHOR]

Aim: As proxy for initiation of the first link in the Chain of Survival by the dispatcher, we aimed to investigate the effect of time to first dispatch on 30-day survival among patients with OHCA ultimately receiving the highest-level emergency medical response.Methods: We linked data on all OHCA unwitnessed by emergency medical services (EMS) treated by Copenhagen EMS from 2016 through 2018 to corresponding emergency call records. Among patients receiving highest priority emergency response, we calculated time to dispatch as time from start of call to time of first dispatch.Results: We included 3548 patients with OHCA. Of these, 94.1% received the highest priority response (median time to dispatch 0.84 min, 25th-75th percentile 0.58-1.24 min). Patients with time to dispatch within one minute compared to three or more minutes were more likely to receive bystander cardiopulmonary resuscitation (77.3 vs 54.2%), bystander defibrillation (11.5 vs 6.5%) and defibrillation by emergency medical services (24.1 vs 7.5%) and were 2.6-fold more likely to survive 30 days after the OHCA (P = 0.004). Results from multivariate logistic regression were similar: odds ratio (OR) of survival 0.83 per minute increase (95% confidence interval 0.70-1.00, P = 0.04). However, survival was similar between those who received highest priority response and those who did not: OR of survival 0.88 (95% confidence interval 0.53-1.46, P = 0.61).Conclusion: Rapid time to dispatch among patients with highest priority response was significantly associated with a higher probability of 30-day survival following OHCA. [ABSTRACT FROM AUTHOR]

Aim: To examine incidence and outcome following out-of-hospital cardiac (OHCA) arrest in a high-risk area characterised by high density of potential bystanders and easy access to nearby automated external defibrillators (AEDs).Methods: This retrospective observational study investigated pre-hospital and in-hospital treatment, as well as survival amongst persons with OHCA at Copenhagen International Airport between May 25, 2015 and May 25, 2019. OHCA data from pre- and in-hospital medical records were obtained and compared with public bystander witnessed OHCAs in Denmark.Results: Of the 23 identified non-traumatic OHCAs, 91.3% were witnessed by bystanders, 73.9% received bystander cardiopulmonary resuscitation (CPR), and 43.5% were defibrillated by a bystander. Survival to hospital discharge was 56.5%, with 100% survival among persons with an initial shockable heart rhythm. Compared with nationwide bystander witnessed OHCAs, persons with OHCA at the airport were less likely to receive bystander CPR (73.9% vs. 89.4%, OR 0.33; 95% CI, 0.13-0.86), more likely to receive bystander defibrillation (43.5% vs. 24.8%, OR 2.32; 95% CI, 1.01-5.31), to achieve return of spontaneous circulation (78.2% vs. 50.6%, OR 3.51; 95% CI, 1.30-9.49), and survive to hospital discharge (56.5% vs. 45.2%, OR 1.58; 95% CI, 0.69-3.62).Conclusion: We found a high proportion of bystander defibrillation indicating that bystanders will quickly apply an AED, when accessible. Importantly, 56% of all persons, and all persons with a shockable heart rhythm survived. These findings suggest increased potential for survival following OHCA and support current guidelines to strategically deploy accessible AEDs in high-risk OHCA areas. [ABSTRACT FROM AUTHOR]

Background: Cardiac arrests are often categorized into two separate groups depending on the location of the arrest: in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA). Despite this distinction, few studies have compared the two groups directly. The aim of this study was to compare patient characteristics, cardiac arrest characteristics, and outcomes for IHCA and OHCA patients.Methods: Data on IHCA and OHCA in Denmark were obtained from two nationwide, prospective registries. All adult (≥18 years old) patients with index IHCA or OHCA from January 1, 2017 to December 31, 2018 were included. Supplementary information on outcomes, hospitalizations, and chronic diseases came from additional national registries. The primary outcome was 30-day survival and secondary outcomes were return of spontaneous circulation (ROSC) and 1-year survival.Results: The study included 3501 patients with IHCA and 8846 patients with OHCA. The two groups were similar in demographics, most comorbidities, and initial cardiac arrest rhythm. In the unadjusted analysis, IHCA was associated with increased survival to 30 days compared to OHCA (risk ratio [RR] = 1.41; 95% CI, 1.30; 1.54) and 1 year (RR = 1.46; 95% CI, 1.33; 1.61). Adjusting for age, sex, and comorbidities did not change the RR substantially. When cardiac arrest characteristics were added to the model, the RR decreased from 1.51 (95% CI, 1.39; 1.65) to 1.06 (95% CI, 0.93; 1.20) for survival to 30 days and from 1.66 (95% CI, 1.50; 1.84) to 1.09 (95% CI, 0.94; 1.26) for survival to 1 year. In all subgroup analyses based on cardiac arrest characteristics (e.g. witnessed status), the association between location and outcome was substantially mitigated compared to the primary analyses.Conclusions: In this large, national study, we found that IHCA and OHCA patients were remarkably similar in demographics and most comorbidities. IHCA patients had better outcomes compared to OHCA patients, although these differences disappeared when comparing patients with similar cardiac arrest characteristics. [ABSTRACT FROM AUTHOR]

Out-of-hospital cardiac arrest (OHCA) is a frequent and lethal condition with a yearly incidence of approximately 5000 in Denmark. Thirty-day survival is associated with the patient's prodromal complaints prior to cardiac arrest. This paper examines the odds of 30-day survival dependent on the reported prodromal complaints among OHCAs witnessed by the emergency medical services (EMS). EMS-witnessed OHCAs in the Capital Region of Denmark from 2016-2018 were included. Calls to the emergency number 1-1-2 and the medical helpline for out-of-hours were analyzed according to the Danish Index; data regarding the OHCA was collected from the Danish Cardiac Arrest Registry. We performed multiple logistic regression to calculate the odds ratio (OR) of 30-day survival with adjustment for sex and age. We identified 311 eligible OHCAs of which 79 (25.4%) survived. The most commonly reported complaints were dyspnea (n = 209, OR 0.79 [95% CI 0.46: 1.36]) and 'feeling generally unwell' (n = 185, OR 1.07 [95% CI 0.63: 1.81]). Chest pain (OR 9.16 [95% CI 5.09:16.9]) and heart palpitations (OR 3.15 [95% CI 1.07:9.46]) had the highest ORs, indicating favorable odds for 30-day survival, while unresponsiveness (OR 0.22 [95% CI 0.11:0.43]) and blue skin or lips (OR 0.30, 95% CI 0.09, 0.81) had the lowest, indicating lesser odds of 30-day survival. Experiencing chest pain or heart palpitations prior to EMS-witnessed OHCA was associated with higher 30-day survival. Conversely, complaints of unresponsiveness or having blue skin or lips implied reduced odds of 30-day survival. [ABSTRACT FROM AUTHOR]

Background: Emergency medical dispatchers fail to identify approximately 25% of cases of out of hospital cardiac arrest, thus lose the opportunity to provide the caller instructions in cardiopulmonary resuscitation. We examined whether a machine learning framework could recognize out-of-hospital cardiac arrest from audio files of calls to the emergency medical dispatch center.Methods: For all incidents responded to by Emergency Medical Dispatch Center Copenhagen in 2014, the associated call was retrieved. A machine learning framework was trained to recognize cardiac arrest from the recorded calls. Sensitivity, specificity, and positive predictive value for recognizing out-of-hospital cardiac arrest were calculated. The performance of the machine learning framework was compared to the actual recognition and time-to-recognition of cardiac arrest by medical dispatchers.Results: We examined 108,607 emergency calls, of which 918 (0.8%) were out-of-hospital cardiac arrest calls eligible for analysis. Compared with medical dispatchers, the machine learning framework had a significantly higher sensitivity (72.5% vs. 84.1%, p < 0.001) with lower specificity (98.8% vs. 97.3%, p < 0.001). The machine learning framework had a lower positive predictive value than dispatchers (20.9% vs. 33.0%, p < 0.001). Time-to-recognition was significantly shorter for the machine learning framework compared to the dispatchers (median 44 seconds vs. 54 s, p < 0.001).Conclusions: A machine learning framework performed better than emergency medical dispatchers for identifying out-of-hospital cardiac arrest in emergency phone calls. Machine learning may play an important role as a decision support tool for emergency medical dispatchers. [ABSTRACT FROM AUTHOR]

This study aimed to design and implement a new variable, the automated external defibrillator (AED) variable, within the Danish Cardiac Arrest Registry. The introduction of the new variable aims to investigate and solve the challenges of reporting out-of-hospital cardiac arrests. This validation study examined all patients with out-of-hospital cardiac arrest from 2016 to 2019. Their medical records were reviewed to establish a variable for AED. All patients with an AED applied were included, and comparative analyses were carried out. The primary outcome was 30-day survival, and the secondary outcome was the return of spontaneous circulation (ROSC) at any time. A total of 1576 cases were included; of those, 747 cases had an AED applied and received a shock, and in 829 cases, an AED was applied without delivering a shock. Most defibrillated patients were witnessed by bystanders n = 541, (72%). They presented a higher number of ROSC (57%) and higher 30-day survival, (35,2%) compared to patients who were not defibrillated. Of this group, only 47% patients were witnessed; 18% survived more than 30 days, p < 0.001. When comparing AED present with no AED present, the AED group were significantly more likely to be witnessed by bystanders and to have cardiopulmonary resuscitation by bystanders. No significant differences were found regarding the initial rhythm between the two groups. 30-day survival rate was 20% in the AED group compared to 14% in the non-AED group, yielding an OR of 1.14 (95% CI 1.20–1.66). This study highlights the differences between OHCA patients receiving defibrillation and those not receiving defibrillation after AED placement. These differences emphasise the need for uniform reporting of out-of-hospital cardiac arrest. This study showed improvement in the completeness of the registration of OHCA by implementing the AED variable. However, a future effort to improve registration completeness is needed. [ABSTRACT FROM AUTHOR]

A machine-learning model trained to recognize emergency calls regarding Out-of-Hospital Cardiac Arrest (OHCA) was tested in clinical practice at Copenhagen Emergency Medical Services (EMS) from September 2018 to December 2019. We aimed to investigate emergency call characteristics where the machine-learning model failed to recognize OHCA or misinterpreted a call as being OHCA. All emergency calls were linked to the dispatch database and verified OHCAs were identified by linkage to the Danish Cardiac Arrest Registry. Calls with either false negative or false positive predictions of OHCA were evaluated by trained auditors. Descriptive analyses were performed with absolute numbers and percentages reported. The machine-learning model processed 169,236 calls to Copenhagen EMS and suspected 5,811 (3.4%) of the calls as OHCA, resulting in 84.5% sensitivity and 97.1% specificity. Among OHCAs not recognised by machine-learning model, a condition completely different from OHCA was presented by caller in 31% of the cases. In 28% of unrecognised calls, patient was reported breathing normally, and language barriers were identified in 23% of the cases. Among falsely suspected OHCA, the patient was reported unconscious in 28% of the cases, and in 13% of the false positive cases the machine-learning model interpreted calls regarding dead patients with irreversible signs of death as OHCA. Continuous optimization of the language model is needed to improve the prediction of OHCA and thereby improve sensitivity and specificity of the machine-learning model on recognising OHCA in emergency telephone calls. [ABSTRACT FROM AUTHOR]

We recognize the importance of the specificity of the machine-learning network, and found in our study, that the machine-learning framework had a specificity of 97.3% (95% CI 97.2%-97.4%). Dr. Müller and Dr. Brejnebøl also suggest that the overall accuracy of the machine-learning framework should be calculated and listed in order to support the statement in the abstract that the machine-learning network overall performed better than dispatchers. [Extracted from the article]

Highlights from the article: B Background: b OHCA is a rare condition for children and young adults. Overall incidence rates are reported as 3.3-5.97 per 100.000 inhabitants.[[1]] Previous studies have identified a diverse and slightly incompatible etiologies.[[2]] The purpose of this study was to analyze presumed etiologies of pediatric OHCA and report incident and survival rates. B Conclusion: b Pediatric OHCA from 2016-2018 had incident rates from 0.83 to 1.34 per 100.000 inhabitants per year, rates of survival to hospital of 46% and the most common cause noted was hypoxia.