Underlying reasons for sex difference in survival following out-of-hospital cardiac arrest: a mediation analysis.

AIMS: Previous studies have indicated a poorer survival among women following out-of-hospital cardiac arrest (OHCA), but the mechanisms explaining this difference remain largely uncertain.This study aimed to assess the survival after OHCA among women and men and explore the role of potential mediators, such as resuscitation characteristics, prior comorbidity, and socioeconomic factors. METHODS AND RESULTS: This was a population-based cohort study including emergency medical service-treated OHCA reported to the Swedish Registry for Cardiopulmonary Resuscitation in 2010-2020, linked to nationwide Swedish healthcare registries. The relative risks (RR) of 30-day survival were compared among women and men, and a mediation analysis was performed to investigate the importance of potential mediators. Total of 43 226 OHCAs were included, of which 14 249 (33.0%) were women. Women were older and had a lower proportion of shockable initial rhythm. The crude 30-day survival among women was 6.2% compared to 10.7% for men [RR 0.58, 95% confidence interval (CI) = 0.54-0.62]. Stepwise adjustment for shockable initial rhythm attenuated the association to RR 0.85 (95% CI = 0.79-0.91). Further adjustments for age and resuscitation factors attenuated the survival difference to null (RR 0.98; 95% CI = 0.92-1.05). Mediation analysis showed that shockable initial rhythm explained ∼50% of the negative association of female sex on survival. Older age and lower disposable income were the second and third most important variables, respectively. CONCLUSION: Women have a lower crude 30-day survival following OHCA compared to men. The poor prognosis is largely explained by a lower proportion of shockable initial rhythm, older age at presentation, and lower income.

Changes in temperature in preheated crystalloids at ambient temperatures relevant to a prehospital setting: an experimental simulation study with the application of prehospital treatment of trauma patients suffering from accidental hypothermia.

BACKGROUND: Accidental hypothermia is common in all trauma patients and contributes to the lethal diamond, increasing both morbidity and mortality. In hypotensive shock, fluid resuscitation is recommended using fluids with a temperature of 37-42°, as fluid temperature can decrease the patient's body temperature. In Sweden, virtually all prehospital services use preheated fluids. The aim of the present study was to investigate how the temperature of preheated infusion fluids is affected by the ambient temperatures and flow rates relevant for prehospital emergency care. METHODS: In this experimental simulation study, temperature changes in crystalloids preheated to 39 °C were evaluated. The fluid temperature changes were measured both in the infusion bag and at the patient end of the infusion system. Measurements were conducted in conditions relevant to prehospital emergency care, with ambient temperatures varying between - 4 and 28 °C and flow rates of 1000 ml/h and 6000 ml/h, through an uninsulated infusion set at a length of 175 cm. RESULTS: The flow rate and ambient temperature affected the temperature in the infusion fluid both in the infusion bag and at the patient end of the system. A lower ambient temperature and lower flow rate were both associated with a greater temperature loss in the infusion fluid. CONCLUSION: This study shows that both a high infusion rate and a high ambient temperature are needed if an infusion fluid preheated to 39 °C is to remain above 37 °C when it reaches the patient using a 175-cm-long uninsulated infusion set. It is apparent that the lower the ambient temperature, the higher the flow rate needs to be to limit temperature loss of the fluid.

Epidemiology of patients assessed for trauma by Swedish ambulance services: a retrospective registry study.

BACKGROUND: There is a lack of knowledge regarding the epidemiology of severe trauma assessed by Swedish emergency medical services (EMS). AIM: To investigate the prevalence of trauma in Sweden assessed by EMS from a national perspective and describe patient demography, aetiology, trauma type, prehospital triage and clinical outcomes. METHODS: Data from two national quality registries, the Swedish Ambulance Registry and the Swedish Trauma Registry (SweTrau) were collected from January 1 to December 31, 2019. Inclusion criteria were an Emergency Symptoms and Signs code equivalent to trauma in the Swedish Ambulance Registry and criteria fulfilled for SweTrau inclusion. Exclusion criteria were patients < 18 years old, those not transported to a hospital and those without a personal identification number. RESULTS: In total, 53,120 patients with trauma were included (14% of primary EMS missions involving a personal identification number). Of those, 2,278 (4.3%) patients (median age: 45 years; 32% women) were reported in SweTrau to have severe or potentially severe trauma (penetrating: 7%, blunt: 93%). In terms of including all causes of trauma, the code for 'trauma alert activation' was most frequent (55%). The most frequent injury mechanism was an injury caused by a car (34%). Most (89%) cases were assigned Priority 1 (life-threatening condition) at the dispatch centre. 62% were regarded as potentially life threatening upon EMS arrival, whereas 29% were assessed as non-life-threatening. Overall, 25% of the patients had new injury severity scores > 15. 12% required invasive treatment, 11% were discharged with severe disability and the 30-day mortality rate was 3.6%. CONCLUSION: In this cross-sectional study, 14% of the primary EMS missions for one year were caused by trauma. However, only a small proportion of these cases are severe injuries, and the risk of severe disabilities and death appears to be limited. The most frequent aetiology of a severe trauma is injury caused by a car, and most severe traumas are blunt. Severe traumas are given the highest priority at the dispatch centre in the vast majority of cases, but nearly one-third of these cases are considered a low priority by the EMS nurse. The latter leaves room for improvement.

Trends in survival after cardiac arrest: a Swedish nationwide study over 30 years.

AIMS: Trends in characteristics, management, and survival in out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) were studied in the Swedish Cardiopulmonary Resuscitation Registry (SCRR). METHODS AND RESULTS: The SCRR was used to study 106 296 cases of OHCA (1990-2020) and 30 032 cases of IHCA (2004-20) in whom resuscitation was attempted. In OHCA, survival increased from 5.7% in 1990 to 10.1% in 2011 and remained unchanged thereafter. Odds ratios [ORs, 95% confidence interval (CI)] for survival in 2017-20 vs. 1990-93 were 2.17 (1.93-2.43) overall, 2.36 (2.07-2.71) for men, and 1.67 (1.34-2.10) for women. Survival increased for all aetiologies, except trauma, suffocation, and drowning. OR for cardiac aetiology in 2017-20 vs. 1990-93 was 0.45 (0.42-0.48). Bystander cardiopulmonary resuscitation increased from 30.9% to 82.2%. Shockable rhythm decreased from 39.5% in 1990 to 17.4% in 2020. Use of targeted temperature management decreased from 42.1% (2010) to 18.2% (2020). In IHCA, OR for survival in 2017-20 vs. 2004-07 was 1.18 (1.06-1.31), showing a non-linear trend with probability of survival increasing by 46.6% during 2011-20. Myocardial ischaemia or infarction as aetiology decreased during 2004-20 from 67.4% to 28.3% [OR 0.30 (0.27-0.34)]. Shockable rhythm decreased from 37.4% to 23.0% [OR 0.57 (0.51-0.64)]. Approximately 90% of survivors (IHCA and OHCA) had no or mild neurological sequelae. CONCLUSION: Survival increased 2.2-fold in OHCA during 1990-2020 but without any improvement in the final decade, and 1.2-fold in IHCA during 2004-20, with rapid improvement the last decade. Cardiac aetiology and shockable rhythms were halved. Neurological outcome has not improved.

Lived experiences of being cared for by ambulance clinicians when experiencing breathlessness-A phenomenological study.

BACKGROUND: Breathlessness is a serious and distressing symptom and a common reason why patients require prehospital care by ambulance clinicians. However, little is known about how patients experience this care when they are in a state of breathlessness. AIM: The aim of this study is to describe the lived experiences of being cared for by ambulance clinicians when experiencing breathlessness. METHODS: Fourteen lifeworld interviews were conducted with patients who experienced breathlessness and were cared for by ambulance clinicians. The interviews were analysed using a qualitative phenomenological approach. FINDINGS: The essential meaning of being cared for by ambulance clinicians when experiencing breathlessness is described in two ways: existential humanising care, in which the experience is that of being embraced by a genuine presence or existential dehumanising care, in which feeling exposed to an objectifying presence is the main experience. This meaning has four constituents: surrendering to and trusting in the care that will come; being exposed to an objectifying presence is violating; being embraced by a genuine presence is relieving; and knowing is dwelling. CONCLUSION: The findings reveal that the ability of ambulance clinicians to provide existential humanising and trustful care, which is the foundation of professional judgement, was essential in how patients responded to and handled the overall situation when breathlessness.

Inequalities in Income and Education Are Associated With Survival Differences After Out-of-Hospital Cardiac Arrest: Nationwide Observational Study.

BACKGROUND: Despite the acknowledged importance of socioeconomic factors as regards cardiovascular disease onset and survival, the relationship between individual-level socioeconomic factors and survival after out-of-hospital cardiac arrest is not established. Our aim was to investigate whether socioeconomic variables are associated with 30-day survival after out-of-hospital cardiac arrest. METHODS: We linked data from the Swedish Registry for Cardiopulmonary Resuscitation with individual-level data on socioeconomic factors (ie, educational level and disposable income) from Statistics Sweden. Confounding and mediating variables included demographic factors, comorbidity, and Utstein resuscitation variables. Outcome was 30-day survival. Multiple modified Poisson regression was used for the main analyses. RESULTS: A total of 31 373 out-of-hospital cardiac arrests occurring in 2010 to 2017 were included. Crude 30-day survival rates by income quintiles were as follows: Q1 (low), 414/6277 (6.6%); Q2, 339/6276 (5.4%); Q3, 423/6275 (6.7%); Q4, 652/6273 (10.4%); and Q5 (high), 928/6272 (14.8%). In adjusted analysis, the chance of survival by income level followed a gradient-like increase, with a risk ratio of 1.86 (95% CI, 1.65-2.09) in the highest-income quintile versus the lowest. This association remained after adjusting for comorbidity, resuscitation factors, and initial rhythm. A higher educational level was associated with improved 30-day survival, with the risk ratio associated with postsecondary education ≥4 years being 1.51 (95% CI, 1.30-1.74). Survival disparities by income and educational level were observed in both men and women. CONCLUSIONS: In this nationwide observational study using individual-level socioeconomic data, higher income and higher educational level were associated with better 30-day survival after out-of-hospital cardiac arrest in both sexes.

Prehospital recognition of stroke is associated with a lower risk of death.

OBJECTIVE: Among patients assessed by the emergency medical service (EMS) and hospitalized with a final diagnosis of stroke, to describe delays, patient characteristics, actions taken and outcome in relation to the early recognition of stroke by the EMS clinician. METHODS: Patients admitted to any of six stroke units in Region Västra Götaland, Sweden, with a final diagnosis of stroke from 1 January 2013 to 31 December 2015 were included. Data on follow-up were retrieved from the Swedish Stroke Register. RESULTS: In all, 5467 patients were included. Stroke was recognized by the EMS clinician in 4396 cases (80.4%). The mean difference in the time from dialling 112 until arrival at the stroke unit was 556 min shorter when stroke was recognized, while the mean difference in the time from dialling 112 until a preliminary report from a computed tomography (CT) scan was 219 min shorter as compared with the patients in whom stroke was not recognized. After adjustment for age, sex, neurological deficits and coma, a lack of suspicion of stroke on EMS arrival was associated with an increased risk of death during three months of follow-up (odds ratio 1.66; 95% confidence interval 1.19-2.32; p = .003). CONCLUSION: Among patients with a stroke, more than 80% were recognized by the EMS clinician. Early recognition of stroke was associated with a markedly shorter time until arrival at the stroke unit and until the preliminary report of a CT scan. A lack of early stroke recognition was associated with an increased risk of death.

Development of a prehospital prediction model for risk stratification of patients with chest pain.

INTRODUCTION: Chest pain is one of the most common reasons for contacting the emergency medical services (EMS). About 15% of these chest pain patients have a high-risk condition, while many of them have a low-risk condition with no need for acute hospital care. It is challenging to at an early stage distinguish whether patients have a low- or high-risk condition. The objective of this study has been to develop prediction models for optimising the identification of patients with low- respectively high-risk conditions in acute chest pain early in the EMS work flow. METHODS: This prospective observational cohort study included 2578 EMS missions concerning patients who contacted the EMS in a Swedish region due to chest pain in 2018. All the patients were assessed as having a low-, intermediate- or high-risk condition, i.e. occurrence of a time-sensitive diagnosis at discharge from hospital. Multivariate regression analyses using data on symptoms and symptom onset, clinical findings including ECG, previous medical history and Troponin T were carried out to develop models for identification of patients with low- respectively high-risk conditions. Developed models where then tested hold-out data set for internal validation and assessing their accuracy. RESULTS: Prediction models for risk-stratification based on variables mutual for both low- and high-risk prediction were developed. The variables included were: age, sex, previous medical history of kidney disease, atrial fibrillation or heart failure, Troponin T, ST-depression on ECG, paleness, pain debut during activity, constant pain, pain in right arm and pressuring pain quality. The high-risk model had an area under the receiving operating characteristic curve of 0.85 and the corresponding figure for the low-risk model was 0.78. CONCLUSIONS: Models based on readily available information in the EMS setting can identify high- and low-risk conditions with acceptable accuracy. A clinical decision support tool based on developed models may provide valuable clinical guidance and facilitate referral to less resource-intensive venues.

Better outcomes from exercise-related out-of-hospital cardiac arrest in males and in the young: findings from the Swedish Registry of Cardiopulmonary Resuscitation.

BACKGROUND: Survival from out-of-hospital cardiac arrest (OHCA) is higher if the arrest is witnessed and occurs during exercise, however, there is contradicting data on prognosis with regards to sex and age. The purpose of this study was to compare the outcomes and circumstances of exercise-related OHCA in different age groups and between sexes in a large unselected population. METHODS: Data from exercise-related OHCAs reported to the Swedish Registry of Cardiopulmonary Resuscitation from 2011 to 2014 and from 2016 to 2018 were analysed. All cases of exercise-related OHCA in which emergency medical services attempted resuscitation were included. The primary outcome was survival to 30 days. RESULTS: In total, 635 cases of exercise-related OHCA outside of the home were identified. The overall 30-day survival rate was 44.5% with highest survival rate in the age group 0-35 years, compared with 36-65 years and >65 years (59.6% vs 46.0% and 40.4%, p=0.01). A subgroup analysis of 0-25 years showed a survival rate of 68.8%. Exercise-related OHCA in females (9.1% of total) were witnessed to a lower extent (66.7% vs 79.6%, p=0.03) and median time to cardiopulmonary resuscitation (CPR) was longer (2.0 vs 1.0 min, p=0.001) than in males. Females also had lower rates of ventricular fibrillation (43.4% vs 64.7%, p=0.003) and a lower 30-day survival rate (29.3% vs 46.0%, p=0.02). CONCLUSION: In exercise-related OHCA, younger victims have a higher survival rate. Exercise-related OHCA in females was rare, however, survival rates were lower compared with males and partly explained by a lower proportion of witnessed events, longer time to CPR and lower frequency of a shockable rhythm.

Discriminatory cardiac arrest care? Patients with low socioeconomic status receive delayed cardiopulmonary resuscitation and are less likely to survive an in-hospital cardiac arrest.

AIMS: Individuals with low socioeconomic status (SES) face widespread prejudice in society. Whether SES disparities exist in treatment and survival following in-hospital cardiac arrest (IHCA) is unclear. The aim of the current retrospective registry study was to examine SES disparities in IHCA treatment and survival, assessing SES at the patient level, and adjusting for major demographic, clinical, and contextual factors. METHODS AND RESULTS: In total, 24 217 IHCAs from the Swedish Register of Cardiopulmonary Resuscitation were analysed. Education and income constituted SES proxies. Controlling for age, gender, ethnicity, comorbidity, heart rhythm, aetiology, hospital, and year, primary analyses showed that high (vs. low) SES patients were significantly less likely to receive delayed cardiopulmonary resuscitation (CPR) (highly educated: OR = 0.89, and high income: OR = 0.98). Furthermore, patients with high SES were significantly more likely to survive CPR (high income: OR = 1.02), to survive to hospital discharge with good neurological outcome (highly educated: OR = 1.27; high income: OR = 1.06), and to survive to 30 days (highly educated: OR = 1.21; and high income: OR = 1.05). Secondary analyses showed that patients with high SES were also significantly more likely to receive prophylactic heart rhythm monitoring (highly educated: OR = 1.16; high income: OR = 1.02), and this seems to partially explain the observed SES differences in CPR delay. CONCLUSION: There are clear SES differences in IHCA treatment and survival, even when controlling for major sociodemographic, clinical, and contextual factors. This suggests that patients with low SES could be subject to discrimination when suffering IHCA.

Cardiac arrest in COVID-19: characteristics and outcomes of in- and out-of-hospital cardiac arrest. A report from the Swedish Registry for Cardiopulmonary Resuscitation.

AIM: To study the characteristics and outcome among cardiac arrest cases with COVID-19 and differences between the pre-pandemic and the pandemic period in out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA). METHOD AND RESULTS: We included all patients reported to the Swedish Registry for Cardiopulmonary Resuscitation from 1 January to 20 July 2020. We defined 16 March 2020 as the start of the pandemic. We assessed overall and 30-day mortality using Cox regression and logistic regression, respectively. We studied 1946 cases of OHCA and 1080 cases of IHCA during the entire period. During the pandemic, 88 (10.0%) of OHCAs and 72 (16.1%) of IHCAs had ongoing COVID-19. With regards to OHCA during the pandemic, the odds ratio for 30-day mortality in COVID-19-positive cases, compared with COVID-19-negative cases, was 3.40 [95% confidence interval (CI) 1.31-11.64]; the corresponding hazard ratio was 1.45 (95% CI 1.13-1.85). Adjusted 30-day survival was 4.7% for patients with COVID-19, 9.8% for patients without COVID-19, and 7.6% in the pre-pandemic period. With regards to IHCA during the pandemic, the odds ratio for COVID-19-positive cases, compared with COVID-19-negative cases, was 2.27 (95% CI 1.27-4.24); the corresponding hazard ratio was 1.48 (95% CI 1.09-2.01). Adjusted 30-day survival was 23.1% in COVID-19-positive cases, 39.5% in patients without COVID-19, and 36.4% in the pre-pandemic period. CONCLUSION: During the pandemic phase, COVID-19 was involved in at least 10% of all OHCAs and 16% of IHCAs, and, among COVID-19 cases, 30-day mortality was increased 3.4-fold in OHCA and 2.3-fold in IHCA.

Prehospital assessment of patients with abdominal pain triaged to self-care at home: an observation study.

BACKGROUND: Patients who call for emergency medical services (EMS) due to abdominal pain suffer from a broad spectrum of diseases, some of which are time sensitive. As a result of the introduction of the concept of 'optimal level of care', some patients with abdominal pain are triaged to other levels of care than in an emergency department (ED). We hypothesised that it could be challenging in a patient safety perspective. AIM: This study aims to describe consecutive patients who call for EMS due to abdominal pain and are triaged to self-care by EMS clinicians. METHODS: This was an observational study performed in an EMS organisation in Western Sweden during 2020. The triage tool Rapid Emergency Triage and Treatment System (RETTS), which included Emergency Signs and Symptom (ESS) codes, was used to find medical records where patients with abdominal pain have been triaged to self-care and 194 patients was included in the study. RESULTS: Of total 48,311 ambulance missions, A total of 1747 patients were labelled with ESS code six (abdominal pain), including 223 (12.8%) who were given the code for self-care and 194 who were further assessed by the research group. Of these patients, 32 (16.3%) had a return visit within 96 hours due to the same symptoms and 11 (5.6%) were hospitalised. In six of these patients, the EMS triage was evaluated retrospectively and assessed as inappropriate. These patients had a final diagnosis of ruptured abdominal aneurysm (n = 1), acute appendicitis with peritonitis (n = 2) and acute pancreatitis (n = 3). All these patients required extensive evaluation and different treatments, including acute surgery, antibiotics and fluid therapy. CONCLUSION: Amongst the 1747 patients assessed by EMS due to abdominal pain, 223 (12.8%) were triaged to self-care. Of the 194 patients who were further assessed, 16.3% required a return visit to the ED within 96 hours and 5.6% were hospitalised. Six patients had obvious time-sensitive conditions. Our study highlights the difficulties in the early assessment of abdominal pain and the requirement for an accurate decision support tool.

Outcome prediction for patients assessed by the medical emergency team: a retrospective cohort study.

BACKGROUND: Medical emergency teams (METs) have been implemented to reduce hospital mortality by the early recognition and treatment of potentially life-threatening conditions. The objective of this study was to establish a clinically useful association between clinical variables and mortality risk, among patients assessed by the MET, and further to design an easy-to-use risk score for the prediction of death within 30 days. METHODS: Observational retrospective register study in a tertiary university hospital in Sweden, comprising 2,601 patients, assessed by the MET from 2010 to 2015. Patient registry data at the time of MET assessment was analysed from an epidemiological perspective, using univariable and multivariable analyses with death within 30 days as the outcome variable. Predictors of outcome were defined from age, gender, type of ward for admittance, previous medical history, acute medical condition, vital parameters and laboratory biomarkers. Identified factors independently associated with mortality were then used to develop a prognostic risk score for mortality. RESULTS: The overall 30-day mortality was high (29.0%). We identified thirteen factors independently associated with 30-day mortality concerning; age, type of ward for admittance, vital parameters, laboratory biomarkers, previous medical history and acute medical condition. A MET risk score for mortality based on the impact of these individual thirteen factors in the model yielded a median (range) AUC of 0.780 (0.774-0.785) with good calibration. When corrected for optimism by internal validation, the score yielded a median (range) AUC of 0.768 (0.762-0.773). CONCLUSIONS: Among clinical variables available at the time of MET assessment, thirteen factors were found to be independently associated with 30-day mortality. By applying a simple risk scoring system based on these individual factors, patients at higher risk of dying within 30 days after the MET assessment may be identified and treated earlier in the process.

Predictors of short- and long-term mortality in critically ill, older adults admitted to the emergency department: an observational study.

BACKGROUND: In the future, we can expect an increase in older patients in emergency departments (ED) and acute wards. The main purpose of this study was to identify predictors of short- and long-term mortality in the ED and at hospital discharge. METHODS: This is a retrospective, observational, single-center, cohort study, involving critically ill older adults, recruited consecutively in an ED. The primary outcome was mortality. All patients were followed for 6.5-7.5 years. The Cox proportional hazards model was used. RESULTS: Regarding all critically ill patients aged ≥ 70 years and identified in the ED (n = 402), there was a significant association between mortality at 30 days after ED admission and unconsciousness on admission (HR 3.14, 95% CI 2.09-4.74), hypoxia on admission (HR 2.51, 95% CI 1.69-3.74) and age (HR 1.06 per year, 95% CI 1.03-1.09), (all p < 0.001). Of 402 critically ill patients aged ≥ 70 years and identified in the ED, 303 were discharged alive from hospital. There was a significant association between long-term mortality and the Charlson Comorbidity Index (CCI) > 2 (HR 1.90, 95% CI 1.46-2.48), length of stay (LOS) > 7 days (HR 1.72, 95% CI 1.32-2.23), discharge diagnosis of pneumonia (HR 1.65, 95% CI 1.24-2.21) and age (HR 1.08 per year, 95% CI 1.05-1.10), (all p < 0.001). The only symptom or vital sign associated with long-term mortality was hypoxia on admission (HR 1.70, 05% CI 1.30-2.22). CONCLUSIONS: Among critically ill older adults admitted to an ED and discharged alive the following factors were predictive of long-term mortality: CCI > 2, LOS > 7 days, hypoxia on admission, discharge diagnosis of pneumonia and age. The following factors were predictive of mortality at 30 days after ED admission: unconsciousness on admission, hypoxia and age. These data might be clinically relevant when it comes to individualized care planning, which should take account of risk prediction and estimated prognosis.

Suboptimal prehospital decision- making for referral to alternative levels of care - frequency, measurement, acceptance rate and room for improvement.

BACKGROUND: The emergency medical services (EMS) have undergone dramatic changes during the past few decades. Increased utilisation, changes in care-seeking behaviour and competence among EMS clinicians have given rise to a shift in EMS strategies in many countries. From transport to the emergency department to at the scene deciding on the most appropriate level of care and mode of transport. Among the non-conveyed patients some may suffer from "time-sensitive conditions" delaying diagnosis and treatment. Thus, four questions arise: 1) How often are time-sensitive cases referred to primary care or self-care advice? 2) How can we measure and define the level of inappropriate clinical decision-making? 3) What is acceptable? 4) How to increase patient safety? MAIN TEXT: To what extent time-sensitive cases are non-conveyed varies. About 5-25% of referred patients visit the emergency department within 72 hours, 5% are hospitalised, 1-3% are reported to have a time-sensitive condition and seven-day mortality rates range from 0.3 to 6%. The level of inappropriate clinical decision-making can be measured using surrogate measures such as emergency department attendances, hospitalisation and short-term mortality. These measures do not reveal time-sensitive conditions. Defining a scoring system may be one alternative, where misclassifications of time-sensitive cases are rated based on how severely they affected patient outcome. In terms of what is acceptable there is no general agreement. Although a zero-vision approach does not seem to be realistic unless under-triage is split into different levels of severity with zero-vision in the most severe categories. There are several ways to reduce the risk of misclassifications. Implementation of support systems for decision-making using machine learning to improve the initial assessment is one approach. Using a trigger tool to identify adverse events is another. CONCLUSION: A substantial number of patients are non-conveyed, including a small portion with time-sensitive conditions. This poses a threat to patient safety. No general agreement on how to define and measure the extent of such EMS referrals and no agreement of what is acceptable exists, but we conclude an overall zero-vision is not realistic. Developing specific tools supporting decision making regarding EMS referral may be one way to reduce misclassification rates.

Randomized comparison of early supplemental oxygen versus ambient air in patients with confirmed myocardial infarction: Sex-related outcomes from DETO2X-AMI.

BACKGROUND: The purpose of this study is to investigate the impact of oxygen therapy on cardiovascular outcomes in relation to sex in patients with confirmed myocardial infarction (MI). METHODS: The DETermination of the role of Oxygen in suspected Acute Myocardial Infarction trial randomized 6,629 patients to oxygen at 6 L/min for 6-12 hours or ambient air. In the present subgroup analysis including 5,010 patients (1,388 women and 3,622 men) with confirmed MI, we report the effect of supplemental oxygen on the composite of all-cause death, rehospitalization with MI, or heart failure at long-term follow-up, stratified according to sex. RESULTS: Event rate for the composite endpoint was 18.1% in women allocated to oxygen, compared to 21.4% in women allocated to ambient air (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.65-1.05). In men, the incidence was 13.6% in patients allocated to oxygen compared to 13.3% in patients allocated to ambient air (HR 1.03, 95% CI 0.86-1.23). No significant interaction in relation to sex was found (P= .16). Irrespective of allocated treatment, the composite endpoint occurred more often in women compared to men (19.7 vs 13.4%, HR 1.51; 95% CI, 1.30-1.75). After adjustment for age alone, there was no difference between the sexes (HR 1.06, 95% CI 0.91-1.24), which remained consistent after multivariate adjustment. CONCLUSION: Oxygen therapy in normoxemic MI patients did not significantly affect all-cause mortality or rehospitalization for MI or heart failure in women or men. The observed worse outcome in women was explained by differences in baseline characteristics, especially age.

Prehospital lactate levels in blood as a seizure biomarker: A multi-center observational study.

OBJECTIVE: The objective of this study was to assess the value of prehospital measurement of lactate level in blood for diagnosis of seizures in cases of transient loss of consciousness. METHODS: Between March 2018 and September 2019, prehospital lactate was measured with a point-of-care device by the emergency medical services in an area serving a population of 900 000. A total of 383 cases of transient loss of consciousness were identified and categorized as tonic-clonic seizure (TCS), other seizure, syncope, or other cause, according to the final diagnosis in the electronic medical records system. Receiver operating characteristic curve analyses were used to identify the optimal lactate cut-off. RESULTS: A total of 383 cases were included (135 TCS, 42 other seizure, 163 syncope, and 43 other causes). The median lactate level in TCS was 7.0 mmol/L, compared to a median of 2.0 mmol/L in all other cases (P < .001). The area under the curve (AUC) of TCS vs nonepileptic causes was 0.87 (95% confidence interval [CI] 0.83-0.91). The optimal cut-off (Youden index, 67.8%) was 4.75 mmol/L, with 79% sensitivity (95% CI 71-85) and 89% specificity (95% CI 85-93) for TCS. SIGNIFICANCE: Prehospital lactate can be a valuable tool for identifying seizures in transient loss of consciousness. For acceptable specificity, a higher cut-off than that previously demonstrated for hospital-based measurements must be used when values obtained close to the time of the event are interpreted.

Difficulties in the prehospital assessment of patients with TIA/stroke.

BACKGROUND: In patients with TIA/stroke, early assessment is critical. AIM: To describe patients who were not directly transported to hospital by ambulance after prehospital assessment. METHODS: Patients hospitalized with TIA/stroke in Gothenburg, Data were obtained from the EMS and hospital case record system. RESULTS: There were 7,812 patients with TIA/stroke, of which 4,853 (62%) were candidates for EMS transport. Among them, 176 (3.6%) were not directly transported to hospital by ambulance. In 45% of them, delay from symptom onset to calling for EMS was ≤24 hours. On EMS arrival, common symptom was dizziness (28%), followed by weakness in arm or leg (21%), loss of sensibility (13%), speech disturbances (7%), and facial numbness (4%). The modified National Institute of Health Stroke Score (mNIHSS) was 0 in 80% and >1 in two per cent. The NIHSS at the emergency department was 1-4 in 39% and 5-15 in six per cent. The EMS clinician made the decision not to transport the patient to hospital by the EMS in 84%, the dispatcher in 12% and the patient or relatives in four per cent. Patients were involved in the decision in 51%. Final diagnosis was stroke in 74% and the proportion who were independent in normal daily activities at hospital discharge decreased by 15% compared with before event. CONCLUSION: About 3%-4% of patients with TIA/stroke were not directly transported to hospital by EMS after prehospital assessment. The most common symptom was dizziness. Decision-support tools for EMS to identify time-sensitive conditions are required.

Limited need for hospital resources among patients brought to hospital by the emergency medical services.

BACKGROUND: In Sweden, the majority of patients who are transported to hospital by the emergency medical services (EMS) are relatively old and the majority suffer from comorbidity. About half these patients are admitted to a hospital ward and will stay in hospital. However, the other half will only make a visit to the emergency department (ED). The burden on the ED is extensive and many elderly patients have to stay for many hours in the ED. AIM: To describe the patients who are brought to hospital by the EMS, with particular emphasis on those that were discharged from the ED, and to assess the proportion of these patients who did not require hospital resources, which could mean that they were candidates for primary care (PC). METHODS: An observational analysis of a cohort of patients who were transported to hospital by the EMS in 2016 in the Municipality of Gothenburg. RESULTS: In all, 5,326 patients were transported to hospital by the EMS of which 52% were discharged directly from the ED. These patients included 37% assessed as not requiring hospital resources. The three most common causes of contact with the EMS in this subset were abdominal pain (15%), back pain (8%) and non-specified disease (7%). Of these patients, 77% had contact with a physician in the ED, whereas 6% had contact with a nurse and 17% left the ED without any contact. Twenty-six per cent were given advice on follow-up in PC. CONCLUSIONS: Among patients who were brought to hospital by the EMS, more than half were discharged directly from the ED. Among these patients, 37% were assessed as not requiring hospital resources. These patients comprised 15% of the overall study cohort and may be candidates for primary care.

Survival in Out-of-Hospital Cardiac Arrest After Standard Cardiopulmonary Resuscitation or Chest Compressions Only Before Arrival of Emergency Medical Services: Nationwide Study During Three Guideline Periods.

BACKGROUND: In out-of-hospital cardiac arrest, chest compression-only cardiopulmonary resuscitation (CO-CPR) has emerged as an alternative to standard CPR (S-CPR), using both chest compressions and rescue breaths. Since 2010, CPR guidelines recommend CO-CPR for both untrained bystanders and trained bystanders unwilling to perform rescue breaths. The aim of this study was to describe changes in the rate and type of CPR performed before the arrival of emergency medical services (EMS) during 3 consecutive guideline periods in correlation to 30-day survival. METHODS: All bystander-witnessed out-of-hospital cardiac arrests reported to the Swedish register for cardiopulmonary resuscitation in 2000 to 2017 were included. Nonwitnessed, EMS-witnessed, and rescue breath-only CPR cases were excluded. Patients were categorized as receivers of no CPR (NO-CPR), S-CPR, or CO-CPR before EMS arrival. Guideline periods 2000 to 2005, 2006 to 2010, and 2011 to 2017 were used for comparisons over time. The primary outcome was 30-day survival. RESULTS: A total of 30 445 patients were included. The proportions of patients receiving CPR before EMS arrival changed from 40.8% in the first time period to 58.8% in the second period, and to 68.2% in the last period. S-CPR changed from 35.4% to 44.8% to 38.1%, and CO-CPR changed from 5.4% to 14.0% to 30.1%, respectively. Thirty-day survival changed from 3.9% to 6.0% to 7.1% in the NO-CPR group, from 9.4% to 12.5% to 16.2% in the S-CPR group, and from 8.0% to 11.5% to 14.3% in the CO-CPR group. For all time periods combined, the adjusted odds ratio for 30-day survival was 2.6 (95% CI, 2.4-2.9) for S-CPR and 2.0 (95% CI, 1.8-2.3) for CO-CPR, in comparison with NO-CPR. S-CPR was superior to CO-CPR (adjusted odds ratio, 1.2; 95% CI, 1.1-1.4). CONCLUSIONS: In this nationwide study of out-of-hospital cardiac arrest during 3 periods of different CPR guidelines, there was an almost a 2-fold higher rate of CPR before EMS arrival and a concomitant 6-fold higher rate of CO-CPR over time. Any type of CPR was associated with doubled survival rates in comparison with NO-CPR. These findings support continuous endorsement of CO-CPR as an option in future CPR guidelines because it is associated with higher CPR rates and overall survival in out-of-hospital cardiac arrest.