Patients' use of Danish emergency medical services before and during the COVID-19 pandemic: a register-based study.

BACKGROUND: During the COVID-19 pandemic, disturbing images of ambulances unable to respond to the demands for prehospital assistance appeared from several parts of the world. In Denmark, however, a notion occurred that the demands for emergency medical assistance declined. The purpose of this study was to compare the patients' use of the Danish Emergency Medical Services (EMS) before and during the COVID-19 pandemic. Furthermore, we investigated the overall mortality of the ambulance population, the main reason for calling the emergency medical dispatch centre, and the diagnosis assigned to the admitted patients. METHODS: The study was a nationwide registry-based cohort study based on the national prehospital medical records and the Danish National Patient Registry. The primary outcome was the requested number of ambulances. Secondary outcomes included the primary reason for contact with the dispatch centre (reflected by the dispatch criteria), patient mortality, and the diagnoses assigned to the patients transported to the hospital by ambulance during the COVID-19 pandemic in Denmark in March-December 2020. Comparisons were made using a similar period in 2019 before the pandemic. RESULTS: In comparison with the baseline values before the pandemic, the total number of patients treated by the EMS was reduced by 4.5% during the COVID-19 pandemic. The number of patients transported to the hospital during the pandemic was similarly reduced by 3.5%. Compared with baseline values, fewer were patients hospitalised with respiratory diseases during the pandemic (a reduction of 53.3% from April 2019 to April 2020). Compared to the baseline period, there were significant increases in both the 48-h mortality (from 1.4% to 1.5%) and the 30-day mortality (from 4.9% to 5.4%) (p < 0.03 and p < 0.001, respectively), in patients hospitalised during the pandemic. CONCLUSION: During the first wave of the COVID-19 pandemic, the Danish EMS experienced an overall reduction in the requests for and the use of ambulances and, especially, in the number of patients admitted to hospitals for respiratory diseases. Despite the overall reduction in EMS requests, the mortality of the ambulance population increased, indicating that despite the reduced ambulance use, the prehospital population was more severely ill during the pandemic.

Survival of the fastest? A descriptive analysis of severely injured trauma patients primarily admitted or secondarily transferred to major trauma centers in a Danish inclusive trauma system.

BACKGROUND: Trauma systems are crucial for enhancing survival and quality of life for trauma patients. Understanding trauma triage and patient outcomes is essential for optimizing resource allocation and trauma care. AIMS: The aim was to explore prehospital trauma triage in Region Zealand, Denmark. Specifically, characteristics for patients who were either primarily admitted or secondarily transferred to major trauma centers were described. METHODS: A retrospective descriptive study of severely injured trauma patients was conducted from January 2017 to December 2021. RESULTS: The study comprised 744 patients including 55.6% primary and 44.4% secondary patients. Overall, men accounted for 70.2% of patients, and 66.1% were aged 18-65 years. The secondary patients included more women-34.2% versus 26.3% and a higher proportion of Injury Severity Score of ≥ 15-59.6% versus 47.8%, compared to primary patients. 30-day survival was higher for secondary patients-92.7% versus 87%. Medical dispatchers assessed urgency as Emergency level A for 98.1% of primary patients and 86.3% for secondary patients. Physician-staffed prehospital units attended primary patients first more frequently-17.1% versus 3.5%. Response times were similar, but time at scene was longer for primary patients whereas time from injury to arrival at a major trauma center was longer for secondary patients. CONCLUSIONS: Secondary trauma patients had higher Injury Severity Scores and better survival rates. They were considered less urgent by medical dispatchers and less frequently assessed by physician-staffed units. Prospective quality data are needed for further investigation of optimal triage and continuous quality improvement in trauma care.

Time From Distress Call to Percutaneous Coronary Intervention and Outcomes in Myocardial Infarction.

Background: Early percutaneous coronary intervention (PCI) is recommended for ST-segment elevation myocardial infarction (STEMI) treatment. Delays in time-to-PCI, kept within guideline recommendations, have seldom been investigated. Objectives: The purpose of this study was to investigate the consequences of delay, due to system factors or hospital distance, for the time between last patient distress call and PCI. Methods: Registry-based cohort study including times of first call to medical services, admission and PCI for patients admitted with STEMI in Copenhagen, Denmark (2014-2018). The main combined outcome included death, recurrent myocardial infarction, or heart failure estimated at 30 days and 1 year from event. Outcomes according to time from call to PCI (system delay) and door-to-balloon time were standardized to the STEMI population using multivariate logistic regression. Results: In total, 1,822 STEMI patients (73.5% male, median age 63.3 years [Q1-Q3: 54.6-72.9 years]) called the emergency services ≤72 hours before PCI (1,735, ≤12 hours). The combined endpoint of 1-year cumulative incidence was 13.9% (166/1,196) for patients treated within 120 minutes of the call and 21.2% (89/420) for patients treated later. Standardized 30-day outcomes were 7.33% (95% CI: 5.41%-9.63%) for patients treated <60 minutes, and 11.1% (95% CI: 8.39%-14.2%) for patients treated >120 minutes. Conclusions: The risk of recurrent myocardial infarction, death, and heart failure following PCI treatment of STEMI increases rapidly when delay exceeds 1 hour. This indicates a particular advantage of minimizing time from first contact to PCI.

Prevalence and prognostic relevance of electrocardiographic abnormalities among patients with ANCA-associated vasculitis.

OBJECTIVES: Current guidelines provide limited evidence for cardiovascular screening in ANCA-associated vasculitis (AAV). This study aimed to investigate the prevalence of electrocardiogram (ECG) abnormalities and associations between no, minor or major ECG abnormalities with cardiovascular mortality in AAV patients compared with matched controls. METHOD: Using a risk-set matched cohort design, patients diagnosed with granulomatosis with polyangiitis or microscopic polyangiitis with digital ECGs were identified from Danish registers from 2000-2021. Patients were matched 1:3 to controls without AAV on age, sex, and year of ECG measurement. Associated hazards of cardiovascular mortality according to ECG abnormalities were assessed in Cox regression models adjusted for age, sex, and comorbidities, with subsequent computation of 5-year risk of cardiovascular mortality standardized to the age- and sex-distribution of the sample. RESULTS: A total of 1431 AAV patients were included (median age: 69 years, 52.3% male). Median follow-up was 4.8 years. AAV was associated with higher prevalence of left ventricular hypertrophy (17.5% vs 12.5%), ST-T deviations (10.1% vs 7.1%), atrial fibrillation (9.6% vs 7.5%), and QTc prolongation (5.9% vs 3.6%). Only AAV patients with major ECG abnormalities demonstrated significantly elevated risk of cardiovascular mortality [HR 1.99 (1.49-2.65)] compared with controls. This corresponded to a 5-year risk of cardiovascular mortality of 19.14% (16-22%) vs 9.41% (8-11%). CONCLUSION: Patients with AAV demonstrated a higher prevalence of major ECG abnormalities than controls. Notably, major ECG abnormalities were associated with a significantly increased risk of cardiovascular mortality. These results advocate for the inclusion of ECG assessment into routine clinical care for AAV patients.

Prehospital Pulse-Dose Glucocorticoid in ST-Segment Elevation Myocardial Infarction: The PULSE-MI Randomized Clinical Trial.

Importance: In patients with ST-segment elevation myocardial infarction (STEMI), acute inflammation is related to the extent of myocardial damage and may increase infarct size. Thus, administration of pulse-dose glucocorticoid in the very early phase of infarction may reduce infarct size. Objective: To determine the cardioprotective effect of prehospital pulse-dose glucocorticoid in patients with STEMI. Design, Setting, and Participants: This was a 1:1 investigator-initiated, blinded, placebo-controlled, randomized clinical trial conducted between November 14, 2022, and October 17, 2023, with last follow-up on January 17, 2024. Patients 18 years and older with less than 12 hours of acute chest pain and STEMI were included in the prehospital setting throughout the Region Zealand and Capital Region of Denmark and transferred to Rigshospitalet, Denmark. Intervention: Patients were randomly allocated to intravenous glucocorticoid (methylprednisolone, 250 mg) or placebo in the prehospital setting. Main Outcomes and Measures: The primary outcome was final infarct size on cardiac magnetic resonance (CMR) at 3 months. The power calculation was based on an anticipated final infarct size of 13%. Secondary outcomes included CMR outcomes on acute scan and at 3 months, peak of cardiac biomarkers, clinical end points at 3 months, and adverse events. Results: Of 530 included patients (median [IQR] age, 65 [56-75] years; 418 male [78.9%]) with STEMI, 401 (76%) were assessed for the primary outcome, with 198 patients treated with glucocorticoid and 203 with placebo. Median final infarct size was similar in the treatment groups (glucocorticoid, 5%; IQR, 2%-11% vs placebo, 6%; IQR, 2%-13%; P = .24). Compared with placebo, the glucocorticoid group had smaller acute infarct size (odds ratio, 0.78; 95% CI, 0.61-1.00), less microvascular obstruction (relative risk ratio, 0.83; 95% CI, 0.71-0.99), and greater acute left ventricular ejection fraction (mean difference, 4.44%; 95% CI, 2.01%-6.87%). Other secondary outcomes were similar in both groups. Conclusions and Relevance: In patients with STEMI, treatment with prehospital pulse-dose glucocorticoid did not reduce final infarct size after 3 months. However, the trial was likely underpowered as the final infarct size was smaller than anticipated. The glucocorticoid group had improved acute parameters compared with placebo. Trial Registration: ClinicalTrials.gov Identifier: NCT05462730.

"I think we should wait and see": A qualitative study of call-takers' decision-making in consultations with patients suffering unrecognized myocardial infarction.

OBJECTIVES: Call-takers face a complex situation when assessing medical problems in emergency medical services calls. Patients with myocardial infarction experiencing atypical symptoms risk misinterpretation. We examined development in call-takers' decision-making process in telephone consultations with patients having imminent myocardial infarction. METHODS: Recording of 38 calls among 19 patients (two per patient) who contacted Copenhagen Emergency Medical Services (Denmark) at least twice within one week before myocardial infarction diagnosis. The penultimate and last call were compared using qualitative content analysis. RESULTS: Call-takers' assessment of the condition changed from unclear symptom picture and dismissal of heart disease in penultimate call to severe condition, not heart-related, and possible heart disease in last call. Call-takers recommended watchful waiting in the penultimate call. Both calls involved response negotiation, while caution regarding misinterpretation was only seen in the penultimate call. CONCLUSION: Call-takers used different decision-making approaches when the caller's symptom descriptions appeared unclear and not corresponding with the medical understanding of severe conditions. Call-takers did not negotiate the condition's assessment but engaged in discussions about the response choice. PRACTICE IMPLICATIONS: A protocol to negotiate response choice with callers having unclear clinical conditions should be developed. Clarifying watchful waiting as a recommendation may assist call-takers' decision-making.

Head injuries related to bicycle collisions and helmet use - an observational study.

OBJECTIVES: In Denmark, the use of bicycles is widespread, and head injuries are often seen in cyclists involved in collisions. Despite the well-known effects of using a helmet to reduce head injuries, using helmets is not mandatory in Denmark. The primary objective of this study was to provide data regarding injury outcomes and helmet usage. METHODS: Participants were bicyclists who sustained head injuries in bicycle collisions and were assessed by the Copenhagen Emergency Medical Services between 1 January 2016; and 15 June 2019. Patients with suspected head injury were identified in an electronic prehospital patient record. Data were linked to the Danish National Patient Registry to retrieve the diagnosis and were categorized into head injury or no head injury based on the diagnosis. Adjusted logistic regression analyses were reported with odds ratios and corresponding confidence intervals to assess the risk of head injury while adjusting for risk factors like age, sex, alcohol consumption, occurrence during weekends and traumatic brain injury. RESULTS: A total of 407 patients were included in this study. Within this entity, 247 (61%) had sustained a head injury. The use of a helmet was reported in one-third of the included patients. Among the head-injured patients, 13% sustained moderate to severe head injuries. Patients with suspected alcohol involvement were significantly less likely to report the use of a helmet. Helmet use reduced the risk of head injury with an odds ratio of 0.52, (95% CI 0.31 - 0.86). In high-energy trauma, the use of a helmet showed a significant reduction in the risk of sustaining a head injury with an odds ratio of 0.28, (95% CI 0.12 - 0.80). CONCLUSIONS: In this study, using a helmet was associated with a significantly decreased risk of head injury; this association was even more significant in high-energy trauma.

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.

Prediction model for future OHCAs based on geospatial and demographic data: An observational study.

This study used demographic data in a novel prediction model to identify areas with high risk of out-of-hospital cardiac arrest (OHCA) in order to target prehospital preparedness. We combined data from the nationwide Danish Cardiac Arrest Registry with geographical- and demographic data on a hectare level. Hectares were classified in a hierarchy according to characteristics and pooled to square kilometers (km2). Historical OHCA incidence of each hectare group was supplemented with a predicted annual risk of at least 1 OHCA to ensure future applicability. We recorded 19,090 valid OHCAs during 2016 to 2019. The mean annual OHCA rate was highest in residential areas with no point of public interest and 100 to 1000 residents per hectare (9.7/year/km2) followed by pedestrian streets with multiple shops (5.8/year/km2), areas with no point of public interest and 50 to 100 residents (5.5/year/km2), and malls with a mean annual incidence per km2 of 4.6. Other high incidence areas were public transport stations, schools and areas without a point of public interest and 10 to 50 residents. These areas combined constitute 1496 km2 annually corresponding to 3.4% of the total area of Denmark and account for 65% of the OHCA incidence. Our prediction model confirms these areas to be of high risk and outperforms simple previous incidence in identifying future risk-sites. Two thirds of out-of-hospital cardiac arrests were identified in only 3.4% of the area of Denmark. This area was easily identified as having multiple residents or having airports, malls, pedestrian shopping streets or schools. This result has important implications for targeted intervention such as automatic defibrillators available to the public. Further, demographic information should be considered when implementing such interventions.

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.

Association Between Defibrillation Using LIFEPAK 15 or ZOLL X Series and Survival Outcomes in Out-of-Hospital Cardiac Arrest: A Nationwide Cohort Study.

BACKGROUND: Defibrillation is essential for achieving return of spontaneous circulation (ROSC) following out-of-hospital cardiac arrest (OHCA) with shockable rhythms. This study aimed to investigate if the type of defibrillator used was associated with ROSC in OHCA. METHODS AND RESULTS: This study included adult patients with OHCA from the Danish Cardiac Arrest Registry from 2016 to 2021 with at least 1 defibrillation by the emergency medical services. We used multivariable logistic regression and a difference-in-difference analysis, including all patients with or without emergency medical services shock to assess the causal inference of using the different defibrillator models (LIFEPAK or ZOLL) for OHCA defibrillation. Among 6516 patients, 77% were male, the median age (quartile 1; quartile 3) was 70 (59; 79), and 57% achieved ROSC. In total, 5514 patients (85%) were defibrillated using LIFEPAK (ROSC: 56%) and 1002 patients (15%) were defibrillated using ZOLL (ROSC: 63%). Patients defibrillated using ZOLL had an increased adjusted odds ratio (aOR) for ROSC compared with LIFEPAK (aOR, 1.22 [95% CI, 1.04-1.43]). There was no significant difference in 30-day mortality (aOR, 1.11 [95% CI, 0.95-1.30]). Patients without emergency medical services defibrillation, but treated by ZOLL-equipped emergency medical services, had a nonsignificant aOR for ROSC compared with LIFEPAK (aOR, 1.10 [95% CI, 0.99-1.23]) and the difference-in-difference analysis was not statistically significant (OR, 1.10 [95% CI, 0.91-1.34]). CONCLUSIONS: Defibrillation using ZOLL X Series was associated with increased odds for ROSC compared with defibrillation using LIFEPAK 15 for patients with OHCA. However, a difference-in-difference analysis suggested that other factors may be responsible for the observed association.

Prodromal complaints and 30-day survival after emergency medical services-witnessed out-of-hospital cardiac arrest.

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

The Danish Nationwide Electrocardiogram (ECG) Cohort.

The electrocardiogram (ECG) is a non-invasive diagnostic tool holding significant clinical importance in the diagnosis and risk stratification of cardiac disease. However, access to large-scale, population-based digital ECG data for research purposes remains limited and challenging. Consequently, we established the Danish Nationwide ECG Cohort to provide data from standard 12-lead digital ECGs in both pre- and in-hospital settings, which can be linked to comprehensive Danish nationwide administrative registers on health and social data with long-term follow-up. The Danish Nationwide ECG Cohort is an open real-world cohort including all patients with at least one digital pre- or in-hospital ECG in Denmark from January 01, 2000, to December 31, 2021. The cohort includes data on standardized and uniform ECG diagnostic statements and ECG measurements including global parameters as well as lead-specific measures of waveform amplitudes, durations, and intervals. Currently, the cohort comprises 2,485,987 unique patients with a median age at the first ECG of 57 years (25th-75th percentiles, 40-71 years; males, 48%), resulting in a total of 11,952,430 ECGs. In conclusion, the Danish Nationwide ECG Cohort represents a novel and extensive population-based digital ECG dataset for cardiovascular research, encompassing both pre- and in-hospital settings. The cohort contains ECG diagnostic statements and ECG measurements that can be linked to various nationwide health and social registers without loss to follow-up.

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.

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.

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.