Treat and release: an observational study of non-conveyed high-acuity dispatches in a Danish emergency medical system.

Non-conveyance refers to the practice of treating a patient on-site without transporting them to a medical facility. It may decrease unnecessary hospital transfers and improve patient satisfaction. Nonetheless, ensuring patient safety remains paramount. The objective of the study was to assess admission to hospital and mortality in non-conveyed patients. This population-based cohort study included all high-acuity dispatches in Region Zealand, Denmark between 2019 and 2022. The primary outcome was admission within 48 h, and the secondary outcome was 30-day mortality. Descriptive statistical analyses were conducted, and logistic regression models were used to estimate adjusted odds ratios and 95% confidence intervals. A non-conveyance rate of 14% was identified in 95,238 transports. Admission within 48 h was seen in 22% of non-conveyed patients vs. 95% in conveyed patients, p < 0.001. The adjusted analysis showed a decreased likelihood of admission within 48 h within non-conveyed patients, with an aOR of 0.01 95% CI (0.01-0.01). Non-conveyed patients had a crude 30-day mortality rate of 2 vs. 6% among conveyed patients, p < 0.001. The adjusted analysis showed an increased likelihood of 30-day mortality in non-conveyed patients with an odds ratio of 1.21, 95% CI (1.05-1.40). Non-conveyed patients constitute a substantial proportion of patients assessed by ambulances following high-acuity dispatch. Less than one in four non-conveyed patients were admitted within 48 h. Despite the low crude mortality in this study, an increased likelihood of mortality was found within the non-conveyed population. However, additional investigation is warranted in future research.

Foreign body airway obstruction resulting in out-of-hospital cardiac arrest in Denmark - Incidence, survival and interventions.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Emergency Medical Services dispatcher recognition of stroke: A systematic review.

PURPOSE: Stroke treatments are time-sensitive, and thus early and correct recognition of stroke by Emergency Medical Services is essential for outcomes. This is particularly important with the adaption of mobile stroke units. In this systematic review, we therefore aimed to provide a comprehensive overview of Emergency Medical Services dispatcher recognition of stroke. METHODS: The review was registered on PROSPERO and the PRISMA guidelines were applied. We searched PubMed, Embase, and Cochrane Review Library. Screening and data extraction were performed by two observers. Risk of bias was assessed using the QUADAS-2 instrument. FINDINGS: Of 1200 papers screened, 24 fulfilled the inclusion criteria. Data on sensitivity was reported in 22 papers and varied from 17.9% to 83.0%. Positive predictive values were reported in 12 papers and ranged from 24.0% to 87.7%. Seven papers reported specificity, which ranged from 20.0% to 99.1%. Six papers reported negative predictive value, ranging from 28.0% to 99.4%. In general, the risk of bias was low. DISCUSSION: Stroke recognition by dispatchers varied greatly, but overall many patients with stroke are not recognised, despite the initiatives taken to improve stroke literacy. The available data are of high quality, however Asian, African, and South American populations are underrepresented. CONCLUSION: While the data are heterogenous, this review can serve as a reference for future research in emergency medical dispatcher stroke recognition and initiatives to improve prehospital stroke recognition.

Association between mortality and phone-line waiting time for non-urgent medical care: a Danish registry-based cohort study.

BACKGROUND AND IMPORTANCE: Telephone calls are often patients' first healthcare service contact, outcomes associated with waiting times are unknown. OBJECTIVES: Examine the association between waiting time to answer for a medical helpline and 1- and 30-day mortality. DESIGN, SETTING AND PARTICIPANTS: Registry-based cohort study using phone calls data (January 2014 to December 2018) to the Capital Region of Denmark's medical helpline. The service refers to hospital assessment/treatment, dispatches ambulances, or suggests self-care guidance. EXPOSURE: Waiting time was grouped into the following time intervals in accordance with political service targets for waiting time in the Capital Region: <30 s, 0:30-2:59, 3-9:59, and ≥10 min. OUTCOME MEASURES AND ANALYSIS: The association between time intervals and 1- and 30-day mortality per call was calculated using logistic regression with strata defined by age and sex. MAIN RESULTS: In total, 1 244 252 callers were included, phoning 3 956 243 times, and 78% of calls waited <10 min. Among callers, 30-day mortality was 1% (16 560 deaths). For calls by females aged 85-110 30-day mortality increased with longer waiting time, particularly within the first minute: 9.6% for waiting time <30 s, 10.8% between 30 s and 1 minute and 9.1% between 1 and 2 minutes. For calls by males aged 85-110 30-day mortality was 11.1%, 12.9% and 11.1%, respectively. Additionally, among calls with a Charlson score of 2 or higher, longer waiting times were likewise associated with increased mortality. For calls by females aged 85-110 30-day mortality was 11.6% for waiting time <30 s, 12.9% between 30 s and 1 minute and 11.2% between 1 and 2 minutes. For calls by males aged 85-110 30-day mortality was 12.7%, 14.1% and 12.6%, respectively. Fewer ambulances were dispatched with longer waiting times (4%/2%) with waiting times <30 s and >10 min. CONCLUSION: Longer waiting times for telephone contact to a medical helpline were associated with increased 1- and 30-day mortality within the first minute, especially among elderly or more comorbid callers.

Ambulance response times and 30-day mortality: a Copenhagen (Denmark) registry study.

BACKGROUND AND IMPORTANCE: Ensuring prompt ambulance responses is complicated and costly. It is a general conception that short response times save lives, but the actual knowledge is limited. OBJECTIVE: To examine the association between the response times of ambulances with lights and sirens and 30-day mortality. DESIGN: A registry-based cohort study using data collected from 2014-2018. SETTINGS AND PARTICIPANTS: This study included 182 895 individuals who, during 2014-2018, were dispatched 266 265 ambulances in the Capital Region of Denmark. OUTCOME MEASURES AND ANALYSIS: The primary outcome was 30-day mortality. Subgroup analyses were performed on out-of-hospital cardiac arrests, ambulance response priority subtypes, and caller-reported symptoms of chest pain, dyspnoea, unconsciousness, and traffic accidents. The relation between variables and 30-day mortality was examined with logistic regression. RESULTS: Unadjusted, short response times were associated with higher 30-day mortality rates across unadjusted response time quartiles (0-6.39 min: 9%; 6.40-8.60 min: 7.5%, 8.61-11.80 min: 6.6%, >11.80 min: 5.5%). This inverse relationship was consistent across subgroups, including chest pain, dyspnoea, unconsciousness, and response priority subtypes. For traffic accidents, no significant results were found. In the case of out-of-hospital cardiac arrests, longer response times of up to 10 min correlated with increased 30-day mortality rates (0-6.39 min: 84.1%; 6.40-8.60 min: 86.7%, 8.61-11.8 min: 87.7%, >11.80 min: 85.5%). Multivariable-adjusted logistic regression analysis showed that age, sex, Charlson comorbidity score, and call-related symptoms were associated with 30-day mortality, but response time was not (OR: 1.00 (95% CI [0.99-1.00])). CONCLUSION: Longer ambulance response times were not associated with increased mortality, except for out-of-hospital cardiac arrests.

Pre-hospital symptoms associated with acute bacterial meningitis differs between children and adults.

Community acquired bacterial meningitis (CABM) is a medical emergency requiring timely appropriate action. More knowledge about pre-hospital symptoms is needed. Retrospective observational study of pre-hospital management in patients with CABM between 2016 and 2021 admitted to a hospital in the Capital Region of Denmark. Reported symptoms were extracted from archived audio files of the initial phone call to emergency medical service. The majority of the 209 patients (82%) were adults. The most common symptoms were altered mental state (58%) and fever (57%), while neck stiffness was less common (9%). Children more often presented with fever, fatigue, rashes, and neck stiffness, while adults more often presented with altered mental state, and leg pain. Most patients (85%) reported at least 1 of the 3 symptoms in the classical triad of meningitis, while 3% reported all 3. Children more often presented at least 2 of 3 symptoms in the triad. One child (3%) and 7 adults (4%) received antibiotics pre-admission. Patients with CABM reported a variety of symptoms that differed significantly in children and adults. The classic triad was rare. Very few patients received antibiotics pre-admission. We suggest that questioning relevant symptoms should be done in febrile or mentally altered patients.

A retrospective study on machine learning-assisted stroke recognition for medical helpline calls.

Advanced stroke treatment is time-dependent and, therefore, relies on recognition by call-takers at prehospital telehealth services to ensure fast hospitalisation. This study aims to develop and assess the potential of machine learning in improving prehospital stroke recognition during medical helpline calls. We used calls from 1 January 2015 to 31 December 2020 in Copenhagen to develop a machine learning-based classification pipeline. Calls from 2021 are used for testing. Calls are first transcribed using an automatic speech recognition model and then categorised as stroke or non-stroke using a text classification model. Call-takers achieve a sensitivity of 52.7% (95% confidence interval 49.2-56.4%) with a positive predictive value (PPV) of 17.1% (15.5-18.6%). The machine learning framework performs significantly better (p < 0.0001) with a sensitivity of 63.0% (62.0-64.1%) and a PPV of 24.9% (24.3-25.5%). Thus, a machine learning framework for recognising stroke in prehospital medical helpline calls may become a supportive tool for call-takers, aiding in early and accurate stroke recognition.

Prehospital interventions and outcomes in traumatic cardiac arrest: a population-based cohort study using the Danish Helicopter Emergency Medical Services data.

BACKGROUND AND IMPORTANCE: Traumatic cardiac arrest is associated with poor prognosis, and timely evidence-based treatment is paramount for increasing survival rates. Physician-staffed helicopter emergency medical service use in major trauma has demonstrated improved outcomes. However, the sparsity of data highlights the necessity for a comprehensive understanding of the epidemiology of traumatic cardiac arrest. OBJECTIVES: The primary objective of the present study was to evaluate survival and return of spontaneous circulation (ROSC) and to investigate the characteristics of patients with traumatic cardiac arrest assessed by the Danish HEMS. DESIGN: This was a population-based cohort study based on data from the Danish helicopter emergency medical service database. SETTINGS AND PARTICIPANTS: The study included all patients assessed by the Danish helicopter emergency medical services between 2016 and 2021. OUTCOME MEASURES AND ANALYSIS: Data were analysed using descriptive statistics, non-parametric testing and logistic regression analyses. Descriptive analysis of prehospital interventions included cardiopulmonary resuscitation, defibrillation, airway management, administration of blood products, and thoracic decompression. The primary outcome was 30-day survival, and the key secondary outcome was prehospital ROSC. MAIN RESULTS: A total of 223 patients with TCA were included. The median age was 54 years (IQR 34-68), and the majority were males. Overall, 23% of patients achieved prehospital ROSC, and the 30-day survival rate was 4%. Factors associated with an increased likelihood of ROSC were an initial shockable cardiac rhythm, odds ratio (OR) of 3.78 (95% CI 1.33-11.00) and endotracheal intubation, OR 7.10 (95% CI 2.55-22.85). CONCLUSION: This study highlights the low survival rates observed among patients with traumatic cardiac arrest assessed by helicopter emergency medical services. The findings support the positive impact of an initial shockable cardiac rhythm and endotracheal intubation in improving the likelihood of ROSC. The study contributes to the limited literature on traumatic cardiac arrests assessed by physician-staffed helicopter emergency services. Finally, the findings emphasise the need for further research to understand and improve outcomes in this subgroup of cardiac arrest.

The Danish National Child Health Register.

Aim of the Database: The aim of the National Child Health Registry is to provide comprehensive insight into children's health and growth on a national scale by continuously monitoring the health status of Danish children. Through this effort, the registry assists the health authorities in prioritizing preventive efforts to promote better child health outcomes. Study Population: The registry includes all Danish children, however, incomplete coverage persists. Main Variables: The National Child Health Registry contains information on exposure to secondhand smoking, breastfeeding duration, and anthropometric measurements through childhood. The information in the registry is divided into three datasets: Smoking, Breastfeeding, and Measurements. Beside specific information on the three topics, all datasets include information on CPR-number, date of birth, sex, municipality, and region of residence. Database Status: The National Child Health Registry was established in 2009 and contains health information on children from all Danish municipalities, collected through routinely performed health examinations conducted by general practitioners and health nurses. Conclusion: The National Child Health Register is an asset to epidemiological and health research with nationwide information on children's health and growth in Denmark. Due to the unique Danish Civil Registration System, it is possible to link data from the National Child Health Register to information from several other national health and social registers which enables longitudinal unambiguous follow-up.

Is dispatcher-assisted cardiopulmonary resuscitation affected by a bystander's emotional stress state in out-of-hospital cardiac arrest?

AIM: The study aimed to investigate whether a bystander's emotional stress state affects dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) in out-of-hospital cardiac arrest (OHCA). The primary outcome was initiation of chest compressions (Yes/No). Secondarily we analysed time until chest compressions were initiated and assessed how dispatchers instructed CPR. METHOD: The study was a retrospective, observational study of OHCA emergency calls from the Capital Region of Denmark. Recorded calls were evaluated by five observers using a pre-defined code catalogue regarding the variables wished investigated. RESULTS: Included were 655 OHCA emergency calls, of which 211 callers were defined as emotionally stressed. When cardiac arrest was recognized, chest compressions were initiated in, respectively, 76.8% of cases with an emotionally stressed caller and 73.9% in cases with a not emotionally stressed caller (2.18 (0.80-7.64)). Cases with an emotionally stressed caller had a longer time until chest compressions were initiated compared to cases with a not emotionally stressed caller, however non-significant (164 s. vs. 146 s.; P = 0.145). The dispatchers were significantly more likely to be encouraging and motivating, and to instruct on speed and depth of chest compressions in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller (1.64 (1.07-2.56); 1.78 (1.13-2.88)). Barriers to CPR were significantly more often reported in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller (1.83 (1.32-2.56)). CONCLUSION: There was no significant difference in initiation of chest compressions or in time until initiation of chest compressions in the two groups. However, the dispatchers were overall more encouraging and motivating, and likely to instruct on speed and depth of chest compressions when the caller was emotionally stressed. Furthermore, barriers to CPR were more often reported in cases with an emotionally stressed caller compared to cases with a not emotionally stressed caller. TRIAL REGISTRATION: We applied for ethical approval from The Danish National Committee on Health Research Ethics, but formal approval was waived. We received permission for storage of data and to use these for research of OHCAs in the Capital Region of Denmark by Danish Data Protection Agency (P-2021-670) and Danish Health Authorities (R-2,005,114). The study is registered at ClinicalTrials (NTC05113706).

Association between using a prehospital assessment unit and hospital admission and mortality: a matched cohort study.

OBJECTIVES: This study aimed to compare hospital admission and 30-day mortality between patients assessed by the prehospital assessment unit (PAU) and patients not assessed by the PAU. DESIGN: This was a matched cohort study. SETTING: This study was conducted between November 2021 and October 2022 in Region Zealand, Denmark. PARTICIPANTS: 989 patients aged >18, assessed by the PAU, were identified, and 9860 patients not assessed by the PAU were selected from the emergency calls using exposure density sampling. EXPOSURE: Patients assessed by the PAU. The PAU is operated by paramedics with access to point-of-care test facilities. The PAU is an alternative response vehicle without the capability of transporting patients. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was hospital admission within 48 hours after the initial call. The key secondary outcomes were admission within 7 days, 30-day mortality and admission within 6 hours. Descriptive statistical analyses were conducted, and logistic regression models were used to estimate adjusted OR (aOR) and 95% CI. RESULTS: Among the PAU assessed, 44.1% were admitted within 48 hours, compared with 72.9% of the non-PAU assessed, p<0.001. The multivariable analysis showed a lower risk of admission within 48 hours and 7 days among the PAU patients, aOR 0.31 (95% CI 0.26 to 0.38) and aOR 0.50 (95% CI 0.38 to 0.64), respectively. The 30-day mortality rate was 3.8% in the PAU-assessed patients vs 5.5% in the non-PAU-assessed patients, p=0.03. In the multivariable analysis, no significant difference was found in mortality aOR 0.99 (95% CI 0.71 to 1.42). No deaths were observed in PAU-assessed patients without subsequent follow-up. CONCLUSION: The recently introduced PAU aims for patient-centred emergency care. The PAU-assessed patients had reduced admissions within 48 hours and 7 days after the initial call. Study findings indicate that the PAU is safe since we identified no significant differences in 30-day mortality. TRIAL REGISTRATION NUMBER: NCT05654909.

Recognition of visual symptoms in stroke: a challenge to patients, bystanders, and Emergency Medical Services.

BACKGROUND: Identification of visual symptoms as a sign of acute stroke can be challenging for both first line healthcare professionals and lay persons. Failed recognition of visual symptoms by medical dispatchers at the Emergency Medical Dispatch Center (EMDC-112) or personnel at the Out-of-Hours Health Service (OOHS) may delay stroke revascularization. We aimed to identify correct system response to visual symptoms in emergency calls. METHODS: Phone calls from patient or bystander to the EMDC-112 or OOHS, which included visual symptoms on patients later verified with stroke/Transient ischemic attack (TIA) diagnosis, were analyzed. Data were stratified according to hospitalization within and after 4.5 h from symptom onset. Descriptive and multiple logistic regression analysis were performed. RESULTS: Of 517 calls identified, 290 calls fulfilled inclusion criteria. Only 30% of the patients received correct visitation by the medical dispatchers and referral to the hospital by a high-priority ambulance. Correct visitation was associated with early contact (adjusted OR: 2.37, 95% CI: 1.11, 5.03), contact to the EMDC-112 (adjusted OR: 3.18, 95% CI: 1.80, 5.62), and when the medical dispatcher asked additional questions on typical stroke symptoms (adjusted OR: 6.36, 95% CI: 3.01, 13.43). No specific visual symptom was associated with stroke recognition and fast hospitalization. CONCLUSIONS: First line healthcare professionals had significant problems in identifying visual symptoms as a sign of acute stroke and eliciting correct response. This highlights an urgent need to improve knowledge of visual symptoms in acute stroke and emphasize correct response to stroke symptoms in general.

Traumatic cardiac arrest - a nationwide Danish study.

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.

Geographical Association Between Basic Life Support Courses and Bystander Cardiopulmonary Resuscitation and Survival from OHCA in Denmark.

Introduction: Annually, approximately 4% of the entire adult population of Denmark participate in certified basic life support (BLS) courses. It is still unknown whether increases in BLS course participation in a geographical area increase bystander cardiopulmonary resuscitation (CPR) or survival from out-of-hospital cardiac arrest (OHCA). The aim of the study was to examine the geographical association between BLS course participation, bystander CPR, and 30-day survival from OHCA. Methods: This nationwide register-based cohort study includes all OHCAs from the Danish Cardiac Arrest Register. Data concerning BLS course participation were supplied by the major Danish BLS course providers. A total of 704,234 individuals with BLS course certificates and 15,097 OHCA were included from the period 2016-2019. Associations were examined using logistic regression and Bayesian conditional autoregressive analyses conducted at municipality level. Results: A 5% increase in BLS course certificates at municipality level was significantly associated with an increased likelihood of bystander CPR prior to ambulance arrival with an adjusted odds ratio (OR) of 1.34 (credible intervals: 1.02;1.76). The same trends were observed for OHCAs in out-of-office hours (4pm-08am) with a significant OR of 1.43 (credible intervals: 1.09;1.89). Local clusters with low rate of BLS course participation and bystander CPR were identified. Conclusion: This study found a positive effect of mass education in BLS on bystander CPR rates. Even a 5% increase in BLS course participation at municipal level significantly increased the likelihood of bystander CPR. The effect was even more profound in out-of-office hours with an increase in bystander CPR rate at OHCA.

Training in Basic Life Support and Bystander-Performed Cardiopulmonary Resuscitation and Survival in Out-of-Hospital Cardiac Arrests in Denmark, 2005 to 2019.

Importance: Strategies to improve survival from out-of-hospital cardiac arrest (OHCA) include mass education of laypersons with no official duty to respond to OHCA. In Denmark, basic life support (BLS) course attendance has been mandated by law in October 2006 for obtaining a driver's license for all vehicles and in vocational education programs. Objectives: To examine the association between yearly BLS course participation rate and bystander cardiopulmonary resuscitation (CPR) and 30-day survival from OHCA and to examine if bystander CPR rate acted as a mediator on the association between mass education of laypersons in BLS and survival from OHCA. Design, Setting, and Participants: This cohort study included outcomes for all OHCA incidents from the Danish Cardiac Arrest Register between 2005 and 2019. Data concerning BLS course participation were supplied by the major Danish BLS course providers. Main Outcomes and Measures: The main outcome was 30-day survival of patients who experienced OHCA. Logistic regression analysis was used to examine the association between BLS training rate, bystander CPR rate, and survival, and a bayesian mediation analysis was conducted to examine mediation. Results: A total of 51 057 OHCA incidents and 2 717 933 course certificates were included. The study showed that the annual 30-day survival from OHCA increased by 14% (odds ratio [OR], 1.14; 95% CI, 1.10-1.18; P < .001) when BLS course participation rate increased by 5% in analysis adjusted for initial rhythm, automatic external defibrillator use, and mean age. An average mediated proportion of 0.39 (95% QBCI, 0.049-0.818; P = .01). In other words, the last result indicated that 39% of the association between mass educating laypersons in BLS and survival was mediated through an increased bystander CPR rate. Conclusions and Relevance: In this cohort study of Danish BLS course participation and survival, a positive association was found between annual rate of mass education in BLS and 30-day survival from OHCA. The association of BLS course participation rate on 30-day survival was mediated by the bystander CPR rate; approximately 60% of the association of BLS course participation rate on 30-day survival was based on factors other than increased CPR rates.

AED applied, not recommending defibrillation - A validation study of the new variable AED in the Danish Cardiac Arrest Registry.

AIM: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

"I just haven't experienced anything like this before": A qualitative exploration of callers' interpretation of experienced conditions in telephone consultations preceding a myocardial infarction.

OBJECTIVES: Callers with myocardial infarction presenting atypical symptoms in telephone consultations when calling out-of-hours medical services risk misrecognition. We investigated characteristics in callers' interpretation of experienced conditions through communication with call-takers. METHODS: Recording of calls resulting in not having an ambulance dispatched for 21 callers who contacted a non-emergency medical helpline, Copenhagen (Denmark), up to one week before they were diagnosed with myocardial infarction. Qualitative content analysis was applied. RESULTS: Awareness of illness, remedial actions and previous experiences contributed to callers' interpretation of the experienced condition. Unclear symptoms resulted in callers reacting to their interpretation by being unsure and worried. Negotiation of the interpretation was seen when callers tested the call-taker's interpretation of the condition and when either caller or call-taker suggested: "wait and see". CONCLUSION: Callers sought to interpret the experienced conditions but faced challenges when the conditions appeared unclear and did not correspond to the health system's understanding of symptoms associated with myocardial infarction. It affected the communicative interaction with the call-taker and influenced the call-taker's choice of response. PRACTICE IMPLICATIONS: Call-takers, as part of the decision-making process, could ask further questions about the caller's insecurity and worry. It might facilitate faster recognition of conditions warranting hospital referral.

Registered prodromal symptoms of out-of-hospital cardiac arrest among patients calling the medical helpline services.

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.

Hypothetical interventions on emergency ambulance and prehospital acetylsalicylic acid administration in myocardial infarction patients presenting without chest pain.

BACKGROUND: Myocardial infarction (MI) patients presenting without chest pain are a diagnostic challenge. They receive suboptimal prehospital management and have high mortality. To elucidate potential benefits of improved management, we analysed expected outcome among non-chest pain MI patients if hypothetically they (1) received emergency ambulances/acetylsalicylic acid (ASA) as often as observed for chest pain patients, and (2) all received emergency ambulance/ASA. METHODS: We sampled calls to emergency and non-emergency medical services for patients hospitalized with MI within 24 h and categorized calls as chest pain/non-chest pain. Outcomes were 30-day mortality and a 1-year combined outcome of re-infarction, heart failure admission, and mortality. Targeted minimum loss-based estimation was used for all statistical analyses. RESULTS: Among 5418 calls regarding MI patients, 24% (1309) were recorded with non-chest pain. In total, 90% (3689/4109) of chest pain and 40% (525/1309) of non-chest pain patients received an emergency ambulance, and 73% (2668/3632) and 37% (192/518) of chest pain and non-chest pain patients received prehospital ASA. Providing ambulances to all non-chest pain patients was not associated with improved survival. Prehospital administration of ASA to all emergency ambulance transports of non-chest pain MI patients was expected to reduce 30-day mortality by 5.3% (CI 95%: [1.7%;9%]) from 12.8% to 7.4%. No significant reduction was found for the 1-year combined outcome (2.6% CI 95% [- 2.9%;8.1%]). In comparison, the observed 30-day mortality was 3% among ambulance-transported chest pain MI patients. CONCLUSIONS: Our study found large differences in the prehospital management of MI patients with and without chest pain. Improved prehospital ASA administration to non-chest pain MI patients could possibly reduce 30-day mortality, but long-term effects appear limited. Non-chest pain MI patients are difficult to identify prehospital and possible unintended effects of ASA might outweigh the potential benefits of improving the prehospital management. Future research should investigate ways to improve the prehospital recognition of MI in the absence of chest pain.

Characteristics of low acuity prehospital emergency patients with 48-h mortality, an observational cohort study.

BACKGROUND: Every year an emergency medical technician or paramedic treats and transports up to several hundred patients. Only some patients are acutely seriously ill, and a few of these show only discrete signs and symptoms of their condition. This study aims to describe patients who died within 48 h of being admitted non-emergently to hospital by ambulance, examine the extent to which critically ill patients are recognized prehospitally, and identify clinical warning signs that might be frequently overlooked. METHOD: Registry based follow-up study on patients receiving an ambulance from the Copenhagen EMS in 2018. Data was included regarding the dispatch of the ambulance from the emergency services disposition system, ICD-10 hospital admission diagnoses from the National Patient Register, 48-h mortality from the Central Person Register and assessment and treatment in the ambulance by reviewing the electronic pre-hospital patient record. RESULTS: In 2018 2279 patients died within 48 h after contact with the EMS, 435 cases met inclusion criteria. The patients' median age was 83 years (IQR 75-90), and 374 (86.0%) had one or more underlying serious medical conditions. A triage category based on vitals and presentation was not assigned by the EMS in 286 (68.9%) cases, of which 38 (13.3%) would meet red and 126 (44.1%) orange criteria. For 409 (94.0%) patients, it was estimated that death within 48 h could not have been avoided prehospitally, and for 26 (6.0%) patients it was uncertain. We found 27 patients with acute aortic syndrome as admission diagnosis, of these nine (33.3%) had not been admitted urgently to a hospital with vascular surgery specialty. CONCLUSIONS: It was estimated that death within 48 h could generally not be avoided prehospitally. The patients' median age was 83 years, and they often had serious comorbidity. Patients whose vital parameters met red or orange triage criteria were to a lesser degree triaged prehospitally, compared to patients in the yellow or green categories. Patients with acute aortic syndrome were not recognized by EMS 33.3% of the time.