Characteristics and outcome among patients who dial for the EMS due to chest pain

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.

Development and validation of a prediction rule for patients suspected of acute coronary syndrome in primary care: a cross-sectional study

OBJECTIVE

To develop and validate a symptom-based prediction rule for early recognition of acute coronary syndrome (ACS) in patients with acute chest discomfort who call out-of-hours services for primary care (OHS-PC).

DESIGN

Cross-sectional study. A diagnostic prediction rule was developed with multivariable regression analyses. All models were validated with internal-external cross validation within seven OHS-PC locations. Both age and sex were analysed as statistical interaction terms, applying for age non-linear effects.

SETTING

Seven OHS-PC in the Netherlands.

PARTICIPANTS

2192 patients who called OHS-PC for acute chest discomfort (pain, pressure, tightness or discomfort) between 2014 and 2017. Backed up recordings of telephone triage conversations were analysed.

PRIMARY AND SECONDARY OUTCOMES MEASURES

Diagnosis of ACS retrieved from the patient's medical records in general practice, including hospital specialists discharge letters. Performance of the prediction rules was calculated with the c-statistic and the final model was chosen based on net benefit analyses.

RESULTS

Among the 2192 patients who called the OHS-PC with acute chest discomfort, 8.3% females and 15.3% males had an ACS. The final diagnostic model included seven predictors (sex, age, acute onset of chest pain lasting less than 12 hours, a pressing/heavy character of the pain, radiation of the pain, sweating and calling at night). It had an adjusted c-statistic of 0.77 (95% CI 0.74 to 0.79) with good calibration.

CONCLUSION

The final prediction model for ACS has good discrimination and calibration and shows promise for replacing the existing telephone triage rules for patients with acute chest discomfort in general practice and OHS-PC.

TRIAL REGISTRATION NUMBER

NTR7331.

Clinical presentation in EMS patients with acute chest pain in relation to sex, age and medical history: prospective cohort study

OBJECTIVE

To assess symptom presentation related to age, sex and previous medical history in patients with chest pain.

DESIGN

Prospective observational cohort study.

SETTING

Two-centre study in a Swedish county emergency medical service (EMS) organisation.

PARTICIPANTS

Unselected inclusion of 2917 patients with chest pain cared for by the EMS during 2018.

DATA ANALYSIS

Multivariate analysis on the association between symptom characteristics, patients' sex, age, previous acute coronary syndrome (ACS) or diabetes and the final outcome of acute myocardial infarction (AMI).

RESULTS

Symptomology in patients assessed by the EMS due to acute chest pain varied with sex and age and also with previous ACS or diabetes. Women suffered more often from nausea (OR 1.6) and pain in throat (OR 2.1) or back (OR 2.1). Their pain was more often affected by palpation (1.7) or movement (OR 1.4). Older patients more often described pain onset while sleeping (OR 1.5) and that the onset of symptoms was slow, over hours rather than minutes (OR 1.4). They were less likely to report pain in other parts of their body than their chest (OR 1.4). They were to a lesser extent clammy (OR 0.6) or nauseous (OR 0.6). These differences were present regardless of whether the symptoms were caused by AMI or not.

CONCLUSIONS

A number of aspects of the symptom of chest pain appear to differ in unselected prehospital patients with chest pain in relation to age, sex and medical history, regardless of whether the chest pain was caused by a myocardial infarction or not. This complicates the possibility in prehospital care of using symptoms to predict the underlying aetiology of acute chest pain.

The potential of new prediction models for emergency medical dispatch prioritisation of patients with chest pain: a cohort study

Objectives

To develop emergency medical dispatch (EMD) centre prediction models with high sensitivity and satisfying specificity to identify high-priority patients and patients suitable for non-emergency care respectively, when assessing patients with chest pain.

Methods

Observational cohort study of 2917 unselected patients with chest pain who contacted an EMD centre in Sweden due to chest pain during 2018. Multivariate logistic regression was applied to develop models predicting low-risk or high-risk condition, that is, occurrence of time-sensitive diagnosis on hospital discharge.

Results

Prediction models were developed for the identification of patients suitable for high- and low-priority dispatch, using 11 and 10 variables respectively. The area under the receiver-operating characteristic curve (AUROC) for the high-risk prediction model was 0.79 and for the low-risk model it was 0.74. When applying the high-risk prediction model, 56% of the EMS missions were given highest priority, compared with 65% with the current standard. When applying the low-risk model, 7% were given the lowest priority compared to 1% for the current standard. The new prediction models outperformed today’s dispatch priority accuracy in terms of sensitivity as well as positive and negative predictive value in both high- and low-risk prediction. The low-risk model predicted almost six times as many patients as having low-risk conditions compared with today’s standard. This was done without increasing the number of high-risk patients wrongly assessed as low-risk.

Conclusions

By introducing prediction models, based on logistic regression analyses, using variables obtained by standard EMD-questions on age, sex, medical history and symptomology, EMD prioritisation can be improved compared with using current criteria index-based ones. This will allow a more efficient emergency medical services resource allocation.

Guideline adherence among prehospital emergency nurses when caring for patients with chest pain: a prospective cohort study

Background

The emergency medical services (EMS) use guidelines to describe optimal patient care for a wide range of clinical conditions and symptoms. The intent is to guide personnel to provide patient care in line with best practice. The aim of this study is to describe adherence to such guidelines among prehospital emergency nurses (PENs) when caring for patients with chest pain.

Objective

To describe guideline adherence among PENs when caring for patients with chest pain. To investigate whether guideline adherence is associated with patient age, sex or final diagnosis of acute myocardial infarction on hospital discharge.

Methods

Guideline adherence in terms of patient examination and pharmaceutical treatment was analysed in a cohort of 2092 EMS missions carried out in 2018 in Region Halland, Sweden. Multivariate regression was used to describe how guideline adherence is associated with patient age, sex and diagnosis on hospital discharge.

Results

Guideline adherence was high regarding examination of vital signs (93%) and electrocardiogram (ECG) registration (96%) but lower in terms of pharmaceutical treatment (ranging from 28 to 90%). Adherence was increased in cases in which the patient ended up with acute myocardial infarction (AMI) as diagnosis on discharge. Patients with AMI were given acetylsalicylic acid by PENs in 50% of cases. Women were less likely than men to receive treatment with acetylsalicylic acid and oxycodone.

Conclusions

Guideline adherence among PENs when caring for patients with chest pain is satisfactory in terms vital signs and ECG registration. Regarding pharmaceutical treatment guideline adherence is defective. Improved adherence is mainly associated with male sex in patients and a diagnosis of AMI on hospital discharge. Defective adherence excludes measures known to improve patients’ prognoses such as treatment with acetylsalicylic acid.

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.

Gender-stratified analyses of symptoms associated with acute coronary syndrome in telephone triage: a cross-sectional study

OBJECTIVES

To identify clinical variables that are associated with the diagnosis acute coronary syndrome (ACS) in women and men with chest discomfort who contact out-of-hours primary care (OHS-PC) by telephone, and to explore whether there are indications whether these variables differ among women and men.

DESIGN

Cross-sectional study in which we compared patient and call characteristics of triage call recordings between women with and without ACS, and men with and without ACS.

SETTING

Nine OHS-PC in the Netherlands.

PARTICIPANTS

993 women and 802 men who called OHS-PC for acute chest discomfort (pain, pressure, tightness or discomfort) between 2014 and 2016.

PRIMARY OUTCOME MEASURE

Diagnosis of ACS retrieved from the patient's medical record in general practice, including hospital specialists' discharge letters.

RESULTS

Among 1795 patients (mean age 58.8 (SD 19.5) years, 55.3% women), 15.0% of men and 8.6% of women had an ACS. In both sexes, retrosternal chest pain was associated with ACS (women with ACS vs without 62.3% vs 40.3%, p=0.002; men with ACS vs without 52.5% vs 39.7%, p=0.032; gender interaction, p=0.323), as was pressing/heavy/tightening pain (women 78.6% vs 61.5%, p=0.011; men 82.1% vs 57.4%, p=<0.001; gender interaction, p=0.368) and radiation to the arm (women 75.6% vs 45.9%, p<0.001; men 56.0% vs 34.8%, p<0.001; gender interaction, p=0.339). Results indicate that only in women were severe pain (65.4% vs 38.1%, p=0.006; gender interaction p=0.007) and radiation to jaw (50.0% vs 22.9%, p=0.007; gender interaction p=0.015) associated with ACS.Ambulances were dispatched equally in women (72.9%) and men with ACS (70.0%).

CONCLUSION

Our results indicate there were more similarities than differences in symptoms associated with the diagnosis ACS for women and men. Important exceptions were pain severity and radiation of pain in women. Whether these differences have an impact on predicting ACS needs to be further investigated with multivariable analyses.

TRIAL REGISTRATION NUMBER

NTR7331.

Prehospital stratification in acute chest pain patient into high risk and low risk by emergency medical service: a prospective cohort study

OBJECTIVES

To describe contemporary characteristics and diagnoses in prehospital patients with chest pain and to identify factors suitable for the early recognition of high-risk and low-risk conditions.

DESIGN

Prospective observational cohort study.

SETTING

Two centre study in a Swedish county emergency medical services (EMS) organisation.

PARTICIPANTS

Unselected inclusion of 2917 patients with chest pain contacting the EMS due to chest pain during 2018.

PRIMARY OUTCOME MEASURES

Low-risk or high-risk condition, that is, occurrence of time-sensitive diagnosis on hospital discharge.

RESULTS

Of included EMS missions, 68% concerned patients with a low-risk condition without medical need of acute hospital treatment in hindsight. Sixteen per cent concerned patients with a high-risk condition in need of rapid transport to hospital care. Numerous variables with significant association with low-risk or high-risk conditions were found. In total high-risk and low-risk prediction models shared six predictive variables of which ST-depression on ECG and age were most important. Previously known risk factors such as history of acute coronary syndrome, diabetes and hypertension had no predictive value in the multivariate analyses. Some aspects of the symptoms such as pain intensity, pain in the right arm and paleness did on the other hand appear to be helpful. The area under the curve (AUC) for prediction of low-risk candidates was 0.786 and for high-risk candidates 0.796. The addition of troponin in a subset increased the AUC to >0.8 for both.

CONCLUSIONS

A majority of patients with chest pain cared for by the EMS suffer from a low-risk condition and have no prognostic reason for acute hospital care given their diagnosis on hospital discharge. A smaller proportion has a high-risk condition and is in need of prompt specialist care. Building models with good accuracy for prehospital identification of these groups is possible. The use of risk stratification models could make a more personalised care possible with increased patient safety.

Evaluation and treatment of pain in the pre-hospital setting. A comparison between patients with a hip injury, chest pain and abdominal pain

BACKGROUND

A large proportion of patients who call 112 in Sweden do so because of pain. The purpose of this study was to compare three of the most common types of pain presented by the patients: chest pain, abdominal pain and hip injury, in terms of initial assessment, intensity, treatment and effect of treatment. The overall rationale was to evaluate whether the early assessment and treatment of pain in the pre-hospital setting is optimal or whether there is room for improvement.

METHODS

Observational study during 2016 including 1234 patients triaged to chest pain, abdominal pain and hip injury by the Emergency Medical Services (EMS) in Gothenburg, Sweden.

RESULTS

Severe pain on the arrival of the EMS was described by 39% of patients with a hip injury, 27% with abdominal pain and 15% with chest pain. Analgesics were given to 58% of patients with a hip injury, 35% with chest pain and 34% with abdominal pain. A lower intensity of pain at re-evaluation was observed in 80% of patients with a hip injury, 57% with chest pain and 43% with abdominal pain. Administration of analgesics increased with the duration of pre-hospital care time in all three groups.

CONCLUSIONS

Patients with a hip injury had the most severe pain and they received most pain-relieving medication. Overall, a relatively small proportion of patients with pain received pain-relieving medication and there appears to be an extensive room for improvement.

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.

Accuracy of telephone triage in primary care patients with chest discomfort: a cross-sectional study

OBJECTIVE

To assess the accuracy of semi-automatic assisted telephone triage in patients with acute chest discomfort against the diagnosis of acute coronary syndrome (ACS) or other life-threatening events (LTEs).

METHODS

A cross-sectional study was performed of telephone conversations with 2023 patients with acute chest discomfort (pain, pressure, tightness or discomfort) who called out-of-hours services for primary care (OHS-PC) between 2014 and 2016. Sensitivity, specificity, positive and negative predicted values were calculated for a high urgency (patient seen within one hour) against the diagnoses of ACS and other LTEs. Diagnoses were retrieved from the patients' medical records in general practice, including hospital specialists' discharge letters.

RESULTS

Of 2023 patients who called because of chest discomfort, 227 (11.2%) had an ACS (men 14.9%, women 8.2%) and 58 (2.9%) had another LTE (men 3.6%, women 2.3%). The sensitivity and specificity of a high Netherlands Triage System (NTS) urgency allocation against ACS/other LTEs were 0.73 (95% CI 0.68 to 0.78) and 0.43 (95% CI 0.40 to 0.45), respectively. In 13.2% of the calls the triage nurse overruled the NTS urgency, mostly by upscaling (11.0%). The sensitivity and specificity of the final urgency allocation were 0.86 (95% CI 0.81 to 0.90) and 0.34 (95% CI 0.32 to 0.37). The positive and negative predictive values of the final urgency were 0.18 (95% CI 0.17 to 0.19) and 0.94 (95% CI 0.92 to 0.95), respectively.

CONCLUSIONS

The semi-automatic triage NTS tool underestimated the urgency in 27% of patients with ACS/other LTEs. Overruling by triage nurses improved safety, but still 14% of men and women with ACS/other LTEs received too low urgency, while efficiency remained poor.

TRIAL REGISTRATION NUMBER

NTR7331.

Chest discomfort at night and risk of acute coronary syndrome: cross-sectional study of telephone conversations

BACKGROUND

During telephone triage, it is difficult to assign adequate urgency to patients with chest discomfort. Considering the time of calling could be helpful.

OBJECTIVE

To assess the risk of acute coronary syndrome (ACS) in certain time periods and whether sex influences this risk.

METHODS

Cross-sectional study of 1655 recordings of telephone conversations of patients who called the out-of-hours services primary care (OHS-PC) for chest discomfort. Call time, patient characteristics, symptoms, medical history and urgency allocation of the triage conversations were collected. The final diagnosis of each call was retrieved at the patient's general practice. Absolute numbers of patients with and without ACS were plotted and risks per hour were calculated. The risk ratio of ACS at night (0 to 9 am) was calculated by comparing to the risk at other hours and was adjusted for gender and age.

RESULTS

The mean age of callers was 58.9 (standard deviation ±19.5) years, 55.5% were women and, in total, 199 (12.0%) had an ACS. The crude risk ratio for an ACS at night was 1.80 (confidence interval 1.39-2.34, P < 0.001): 2.33 (1.68-3.22, P < 0.001) for men and 1.29 (0.83-1.99, P = 0.256) for women. The adjusted risk ratio for ACS of all people at night was 1.82 (1.07-3.10, P = 0.039).

CONCLUSIONS

Patients calling the OHS-PC for chest discomfort between 0 and 9 am have almost twice a higher risk of ACS than those calling other hours, a phenomenon more evident in men than in women. At night, dispatching ambulances more 'straightaway' could be considered for these patients with chest discomfort.

TRIAL NUMBER

NTR7331.

Limited reliability of experts' assessment of telephone triage in primary care patients with chest discomfort

OBJECTIVE

Root cause analyses of serious adverse events (SAE) in out-of-hours primary care (OHS-PC) often point to errors in telephone triage. Such analyses are, however, hampered by hindsight bias. We assessed whether experts, blinded to the outcome, recognize (un)safety of triage of patients with chest discomfort, and we quantified inter-rater reliability.

STUDY DESIGN AND SETTING

This is a case-control study with triage recordings from 2013-2017 at OHS-PC. Cases were missed acute coronary syndromes (ACSs, considered as SAE). These cases were age- and gender-matched 1:8 with the controls, sampled from the remainder of people calling for chest discomfort. Fifteen experts listened to the recordings and rated the safety of triage. We calculated sensitivity and specificity of recognizing an ACS and the intraclass correlation.

RESULTS

In total, 135 calls (15 SAE, 120 matched controls) were relistened. The experts identified ACSs with a sensitivity of 0.86 (95% CI: 0.71-0.95) and a specificity of 0.51 (95% CI: 0.43-0.58). Cases were rated significantly more often as unsafe than the controls (73.3% vs. 22.5%, P < 0.001). The inter-rater reliability for safety was poor: ICC 0.16 (95% CI: 0.00-0.32).

CONCLUSIONS

Blinded experts rated calls of missed ACSs more often as unsafe than matched control calls, but with a low level of agreement among the experts.

Predicting acute coronary syndrome in males and females with chest pain who call an emergency medical communication centre

Background

Chest pain is a frequent reason for calls in emergency medical communication centre (EMCC). Detecting a coronary origin by phone is a challenge. This is especially so as the presentations differ according to gender. We aimed to establish and validate a sex-based model to predict a coronary origin of chest pain in patients calling an EMCC.

Methods

This prospective cohort study enrolled patients at 18 years of age or older who called the EMCC because of non-traumatic chest pain. The main outcome was the diagnosis of acute coronary syndrome (ACS) determined by expert evaluation of patient files.

Results

During 18 months, 3727 patients were enrolled: 2097 (56%) men and 1630 (44%) women. ACS was diagnosed in 508 (24%) men and 139 (9%) women. For men, independent factors associated with an ACS diagnosis were age, tobacco use, severe and permanent pain; retrosternal, breathing non-related and radiating pain; and additional symptoms. The area under the receiver operating characteristic curve (AUC) was 0.76 (95% confidence interval [CI] 0.73–0.79) for predicting ACS. The accuracy of the male model to predict ACS was validated in a validation dataset (Hosmer-Lemeshow test: p = 0.554); the AUC was 0.77 (95%CI 0.73–0.80). For women, independent factors associated with an ACS diagnosis were age ≥ 60 years, personal history of coronary artery disease, and breathing non-related and radiating pain. The AUC was 0.79 (95%CI 0.75–0.83). The accuracy of the female model to predict ACS was not validated in the validation dataset (Hosmer-Lemeshow test: p = 0.035); the AUC was 0.67 (95%CI 0.60–0.74).

Conclusions

Predictors of an ACS diagnosis in patients calling an EMCC for chest pain differ between men and women. We developed an accurate predictive model for men, but for women, the accuracy was poor.

Trial registration

This study is registered with ClinicalTrials.gov (NCT02042209).

Chest pain in the ambulance; prevalence, causes and outcome - a retrospective cohort study

BACKGROUND

Chest pain is common in acute ambulance transports. This study aims to characterize and compare ambulance-transported chest pain patients to non-chest pain patients and evaluate if patient characteristics and accompanying symptoms accessible at the time of emergency call can predict cause and outcome in chest pain patients.

METHODS

Retrospective, observational population-based study, including acute ambulance transports. Patient characteristics and symptoms are included in a multivariable risk model to identify characteristics, associated with being discharged without an acute cardiac diagnosis and surviving 30 days after chest pain event.

RESULTS

In total, 10,033 of 61,088 (16.4%) acute ambulance transports were due to chest pain. In chest pain patients, 30-day mortality was 2.1% (95%CI 1.8-2.4) compared to 6.0% (95%CI 5.7-6.2) in non-chest pain patients. Of chest pain patients, 1054 (10.5%) were diagnosed with acute myocardial infarction, and 5068 (50.5%) were discharged without any diagnosis of disease. This no-diagnosis group had very low 30-day mortality, 0.4% (95%CI 0.2-0.9). Female gender, younger age, chronic pulmonary disease, absence of accompanying symptoms of dyspnoea, radiation, severe pain for > 5 min, clammy skin, uncomfortable, and nausea were associated with being discharged without an acute cardiac diagnosis and surviving 30 days after a chest pain event.

CONCLUSION

Chest pain is a common reason for ambulance transport, but the majority of patients are discharged without a diagnosis and with a high survival rate. Early risk prediction seems to hold a potential for resource downgrading and thus cost-saving in selected chest pain patients.

Optimisation of telephone triage of callers with symptoms suggestive of acute cardiovascular disease in out-of-hours primary care: observational design of the Safety First study

INTRODUCTION

In the Netherlands, the 'Netherlands Triage Standard' (NTS) is frequently used as digital decision support system for telephone triage at out-of-hours services in primary care (OHS-PC). The aim of the NTS is to guarantee accessible, efficient and safe care. However, there are indications that current triage is inefficient, with overestimation of urgency, notably in suspected acute cardiovascular disease. In addition, in primary care settings the NTS has only been validated against surrogate markers, and diagnostic accuracy with clinical outcomes as the reference is unknown. In the Safety First study, we address this gap in knowledge by describing, understanding and improving the diagnostic process and urgency allocation in callers with symptoms suggestive of acute cardiovascular disease, in order to improve both efficiency and safety of telephone triage in this domain.

METHODS AND ANALYSIS

An observational study in which 3000 telephone triage recordings (period 2014-2016) will be analysed. Information is collected from the recordings including caller and symptom characteristics and urgency allocation. The callers' own general practitioners are contacted for the final diagnosis of each contact. We included recordings of callers with symptoms suggestive of acute coronary syndrome (ACS) or transient ischaemic attack (TIA)/stroke. With univariable and multivariable logistic regression analyses the diagnostic accuracy of caller and symptom characteristics will be analysed in terms of predictive values with urgency level, and ACS and TIA/stroke as outcomes, respectively. To further improve our understanding of the triage process at OHS-PC, we will carry out additional studies applying both quantitative and qualitative methods: (i) case-control study on serious adverse events (SAE), (ii) conversation analysis study and (iii) interview study with triage nurses.

ETHICS AND DISSEMINATION

The Medical Ethics Committee Utrecht, the Netherlands endorsed this study (National Trial Register identification: NTR7331). Results will be disseminated at scientific conferences, regional educational sessions and publication in peer-reviewed journals.

Symptom description in patients with chest pain-A qualitative analysis of emergency medical calls involving high-risk conditions

AIMS AND OBJECTIVES

To explore the symptoms descriptions and situational information provided by patients during ongoing chest pain events caused by a high-risk condition.

BACKGROUND

Chest pain is a common symptom in patients contacting emergency dispatch centres. Only 15% of these patients are later classified as suffering from a high-risk condition. Prehospital personnel are largely dependent on symptom characteristics when trying to identify these patients.

DESIGN

Qualitative descriptive.

METHODS

Manifest content analysis of 56 emergency medical calls involving patients with chest pain was carried out. A stratified purposive sampling was used to obtain calls concerning patients with high-risk conditions. These calls were then listened to and transcribed. Thereafter, meaning units were identified and coded and finally categorised. Consolidated criteria for reporting qualitative studies guidelines have been applied.

RESULTS

A wide range of situational information and symptoms descriptions was found. Pain and affected breathing were dominating aspects, but other situational information and several other symptoms were also reported. The situational information and these symptoms were classified into seven categories: Pain narrative, Affected breathing, Bodily reactions, Time, Bodily whereabouts, Fear and concern and Situation management. The seven categories consisted of 17 subcategories.

CONCLUSIONS

Patients with chest pain caused by a high-risk condition present a wide range of symptoms which are described in a variety of ways. They describe different kinds of chest pain accompanied by pain from other parts of the body. Breathing difficulties and bodily reactions such as muscle weakness are also reported. The variety of symptoms and the absence of a typical symptomatology make risk stratification on the basis of symptoms alone difficult.

RELEVANCE TO CLINICAL PRACTICE

This study highlights the importance of an open mind when assessing patients with chest pain and the requirement of a decision support tool in order to improve risk stratification in these patients.

The final assessment and its association with field assessment in patients who were transported by the emergency medical service

Background

In patients who call for the emergency medical service (EMS), there is a knowledge gap with regard to the final assessment after arriving at hospital and its association with field assessment.

Aim

In a representative population of patients who call for the EMS, to describe a) the final assessment at hospital discharge and b) the association between the assessment in the field and the assessment at hospital discharge.

Methods

Thirty randomly selected patients reached by a dispatched ambulance each month between 1 Jan and 31 Dec 2016 in one urban, one rural and one mixed ambulance organisation in Sweden took part in the study. The exclusion criteria were age < 18 years, dead on arrival, transport between health-care facilities and secondary missions. Each patient received a unique code based on the ICD code at hospital discharge and field assessment.

Results

In all, 1080 patients took part in the study, of which 1076 (99.6%) had a field assessment code. A total of 894 patients (83%) were brought to a hospital and an ICD code (ICD-10-SE) was available in 814 patients (91% of these cases and 76% of all cases included in the study). According to these ICD codes, the most frequent conditions were infection (15%), trauma (15%) and vascular disease (9%). The most frequent body localisation of the condition was the thorax (24%), head (16%) and abdomen (13%). In 118 patients (14% of all ICD codes), the condition according to the ICD code was judged as time critical. Among these cases, field assessment was assessed as potentially appropriate in 75% and potentially inappropriate in 12%.

Conclusion

Among patients reached by ambulance in Sweden, 83% were transported to hospital and, among them, 14% had a time-critical condition. In these cases, the majority were assessed in the field as potentially appropriate, but 12% had a potentially inappropriate field assessment. The consequences of these findings need to be further explored.

Electronic supplementary material

The online version of this article (10.1186/s13049-018-0579-x) contains supplementary material, which is available to authorized users.

Sensitivity, specificity, and predictive value of cardiac symptoms assessed by emergency medical services providers in the diagnosis of acute myocardial infarction: a multi-center observational study

Objective

For patients with acute myocardial infarction (AMI), symptoms assessed by emergency medical services (EMS) providers have a critical role in prehospital treatment decisions. The purpose of this study was to evaluate the diagnostic accuracy of EMS provider-assessed cardiac symptoms of AMI.

Methods

Patients transported by EMS to 4 study hospitals from 2008 to 2012 were included. Using EMS and administrative emergency department databases, patients were stratified according to the presence of EMS-assessed cardiac symptoms and emergency department diagnosis of AMI. Cardiac symptoms were defined as chest pain, dyspnea, palpitations, and syncope. Disproportionate stratified sampling was used, and medical records of sampled patients were reviewed to identify an actual diagnosis of AMI. Using inverse probability weighting, verification bias-corrected diagnostic performance was estimated.

Results

Overall, 92,353 patients were enrolled in the study. Of these, 13,971 (15.1%) complained of cardiac symptoms to EMS providers. A total of 775 patients were sampled for hospital record review. The sensitivity, specificity, positive predictive value, and negative predictive value of EMS provider-assessed cardiac symptoms for the final diagnosis of AMI was 73.3% (95% confidence interval [CI], 70.8 to 75.7), 85.3% (95% CI, 85.3 to 85.4), 3.9% (95% CI, 3.6 to 4.2), and 99.7% (95% CI, 99.7 to 99.8), respectively.

Conclusion

We found that EMS provider-assessed cardiac symptoms had moderate sensitivity and high specificity for diagnosis of AMI. EMS policymakers can use these data to evaluate the pertinence of specific prehospital treatment of AMI.

Does the prehospital National Early Warning Score predict the short-term mortality of unselected emergency patients?

OBJECTIVES

The prehospital research field has focused on studying patient survival in cardiac arrest, as well as acute coronary syndrome, stroke, and trauma. There is little known about the overall short-term mortality and its predictability in unselected prehospital patients. This study examines whether a prehospital National Early Warning Score (NEWS) predicts 1-day and 30-day mortalities.

METHODS

Data from all emergency medical service (EMS) situations were coupled to the mortality data obtained from the Causes of Death Registry during a six-month period in Northern Finland. NEWS values were calculated from first clinical parameters obtained on the scene and patients were categorized to the low, medium and high-risk groups accordingly. Sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and likelihood ratios (PLRs and NLRs) were calculated for 1-day and 30-day mortalities at the cut-off risks.

RESULTS

A total of 12,426 EMS calls were included in the study. The overall 1-day and 30-day mortalities were 1.5 and 4.3%, respectively. The 1-day mortality rate for NEWS values ≤12 was lower than 7% and for values ≥13 higher than 20%. The high-risk NEWS group had sensitivities for 1-day and 30-day mortalities 0.801 (CI 0.74-0.86) and 0.42 (CI 0.38-0.47), respectively.

CONCLUSION

In prehospital environment, the high risk NEWS category was associated with 1-day mortality well above that of the medium and low risk NEWS categories. This effect was not as noticeable for 30-day mortality. The prehospital NEWS may be useful tool for recognising patients at early risk of death, allowing earlier interventions and responds to these patients.

Association between use of pre-hospital ECG and 30-day mortality: A large cohort study of patients experiencing chest pain

BACKGROUND

In the assessment of patients with chest pain, there is support for the use of pre-hospital ECG in the literature and in the care guidelines. Using propensity score methods, we aim to examine whether the mere acquisition of a pre-hospital ECG among patients with chest pain affects the outcome (30-day mortality).

METHODS

The association between pre-hospital ECG and 30-day mortality was studied in the overall cohort (n=13151), as well as in the one-to-one matched cohort with 2524 patients not examined with pre-hospital ECG and 2524 patients examined with pre-hospital ECG.

RESULTS

In the overall cohort, 21% (n=2809) did not undergo an ECG tracing in the pre-hospital setting. Among those who had pain during transport, 14% (n=1159) did not undergo a pre-hospital ECG while 32% (n=1135) of those who did not have pain underwent an ECG tracing. In the overall cohort, the OR for 30-day mortality in patients who had a pre-hospital ECG, as compared with those who did not, was 0.63 (95% CI 0.05-0.79; p<0.001). In the matched cohort, the OR was 0.65 (95% CI 0.49-0.85; p<0.001). Using the propensity score, in the overall cohort, the corresponding HR was 0.65 (95% CI 0.58-0.74).

CONCLUSION

Using propensity score methods, we provide real-world data demonstrating that the adjusted risk of death was considerably lower among the cases in whoma pre-hospital ECG was used. The PH-ECG is underused among patients with chest discomfort and the mere acquisition of a pre-hospital ECG may reduce mortality.

Dispatch and prehospital transport for acute septic patients: an observational study

Background

In order to dispatch ambulances with the correct level of urgency, the dispatch center has to balance the perceived urgency and traffic safety considerations with the available resources. As urgency is not clear in all clinical situations, some high urgency patients may end up with a suboptimal mode of transport.

Patients with severe sepsis or septic shock suffer from highly time dependent conditions but they present with a wide range of symptoms, which might be difficult to identify in the dispatch system.

The aim of the study is to investigate the modes of prehospital transport among acute admitted patients with sepsis, severe sepsis and septic shock.

Methods

We included all adult patients (≥15 years) presenting to an acute medical unit at Odense University Hospital with a first-time admission of community-acquired sepsis between September 2010-August 2011. Cases and prehospital ambulance transport were identified by structured manual chart review. In all cases it was registered, whether the ordinary ambulance was assisted by the mobile emergency care unit (MECU), manned by anesthesiologists.

Results

We included 1,713 patients median age 72 years (IQR 57–81), 793 (46.3%) male, 621 (36.3%) had sepsis, 1,071 (62.5%) severe sepsis, and 21 (1.2%) septic shock.

In the group of sepsis patients, 390 (62.8%) arrived without public prehospital transport, 197 (31.7%) were transported by ambulance, and 34 (5.5%) were assisted by MECU. In the group of severe sepsis patients, the same percentage 62.8% arrived without public pre-hospital transport, a lower percentage 28.2% were transported by ambulance, and a larger percentage 9.0% were transported by MECU. Among 21 patients with septic shock, 10 arrived without public pre-hospital transport (47.7%), 7 (33.3%) were transported by ambulance, and 4 (19.0%) by MECU.

The 30-day mortality hazard ratio was associated with mode of transport, with the adjusted highest hazard ratio found in the group of MECU transported patients 1.76 (95%Cl 1.16–2.66).

Conclusions

A substantial proportion of patients with severe sepsis and septic shock arrive to hospital without public prehospital transport or by unspecialized ambulances.

Long-Term Mortality of Emergency Medical Services Patients

STUDY OBJECTIVE

Emergency medical services (EMS) provides out-of-hospital care to patients with life-threatening conditions, but the long-term outcomes of EMS patients are unknown. We seek to determine the long-term mortality of EMS patients in Denmark.

METHODS

We analyzed linked EMS, hospital, and vital status data from 3 of 5 geographic regions in Denmark. We included events from July 1, 2011, to December 31, 2012. We classified EMS events according to primary dispatch category (unconsciousness/cardiac arrest, accidents/trauma, chest pain, dyspnea, neurologic symptoms, and other EMS patients). The primary outcome was 1-year mortality adjusted for age, sex, and Charlson comorbidity index.

RESULTS

Among 142,125 EMS events, primary dispatch categories were unconsciousness or cardiac arrest 5,563 (3.9%), accidents or trauma 40,784 (28.7%), chest pain 20,945 (14.7%), dyspnea 9,607 (6.8%), neurologic symptoms 17,804 (12.5%), and other EMS patients 47,422 (33.4%). One-year mortality rates were unconscious or cardiac arrest 54.7% (95% confidence interval [CI] 53.4% to 56.1%), accidents or trauma 7.8 (95% CI 7.5% to 8.1%), chest pain 8.5% (95% CI 8.1% to 9.0%), dyspnea 27.7% (95% CI 26.7% to 28.7%), neurologic symptoms 14.1% (95% CI 13.6% to 14.7%), and other EMS patients 11.1% (95% CI 10.8% to 11.4%). Compared with other EMS conditions, adjusted 1-year mortality was higher in unconsciousness or cardiac arrest (risk ratio [RR] 2.6; 95% CI 2.5 to 2.7), dyspnea (RR 1.5; 95% CI 1.4 to 1.5), and in neurologic symptoms (RR 1.1; 95% CI 1.0 to 1.1), but lower in chest pain (RR 0.6; 95% CI 0.6 to 0.7) and accidents or trauma (RR 0.8; 95% CI 0.8 to 0.8).

CONCLUSION

EMS patients with unconsciousness or cardiac arrest, dyspnea, and neurologic symptoms are at highest risk of long-term mortality. Our results suggest a potential for outcome improvement in these patients.

Could prioritisation by emergency medicine dispatchers be improved by using computer-based decision support? A cohort of patients with chest pain

BACKGROUND

To evaluate whether a computer-based decision support system could improve the allocation of patients with acute coronary syndrome (ACS) or a life-threatening condition (LTC). We hypothesised that a system of this kind would improve sensitivity without compromising specificity.

METHODS

A total of 2285 consecutive patients who dialed 112 due to chest pain were asked 10 specific questions and a prediction model was constructed based on the answers. We compared the sensitivity of the dispatchers' decisions with that of the model-based decision support model.

RESULTS

A total of 2048 patients answered all 10 questions. Among the 235 patients with ACS, 194 were allocated the highest prioritisation by dispatchers (sensitivity 82.6%) and 41 patients were given a lower prioritisation (17.4% false negatives). The allocation suggested by the model used the highest prioritisation in 212 of the patients with ACS (sensitivity of 90.2%), while 23 patients were underprioritised (9.8% false negatives). The results were similar when the two systems were compared with regard to LTC and 30-day mortality. This indicates that computer-based decision support could be used either for increasing sensitivity or for saving resources. Three questions proved to be most important in terms of predicting ACS/LTC, [1] the intensity of pain, [2] the localisation of pain and [3] a history of ACS.

CONCLUSION

Among patients with acute chest pain, computer-based decision support with a model based on a few fundamental questions could improve sensitivity and reduce the number of cases with the highest prioritisation without endangering the patients.

Presenting characteristics and processing times for culturally and linguistically diverse (CALD) patients with chest pain in an emergency department: Time, Ethnicity, and Delay (TED) Study II

BACKGROUND

To date there has been limited published data presenting the characteristics and timeliness of the management in an Emergency Department (ED) for culturally and linguistically diverse (CALD) patients presenting with chest pain. This study aimed to describe the presenting characteristics and processing times for CALD patients with chest pain compared to the Australian-born population, and current guidelines.

METHODS

This study was a cross sectional analysis of a cohort of patients who presented with chest pain to the metropolitan hospital between 1 July 2012 and 30 June 2014.

RESULTS

Of the total study population (n=6640), 1241 (18.7%) were CALD and 5399 (81.3%) were Australian-born. CALD patients were significantly older than Australian-born patients (mean age 62 vs 56years, p<0.001). There were no differences in the proportion of patients who had central chest pain (74.9% vs 75.7%, p=0.526); ambulance utilisation (41.7% vs 41.1%, p=0.697); and time to initial treatment in ED (21 vs 22min, p=0.375). However, CALD patients spent a significantly longer total time in ED (5.4 vs 4.3h, p<0.001). There was no difference in guideline concordance between the two groups with low rates of 12.5% vs 13%, p=0.556. Nonetheless, CALD patients were 22% (95% CI, 0.65, 0.95, p=0.015) less likely to receive the guideline management for chest pain.

CONCLUSIONS

The initial emergency care was equally provided to all patients in the context of a low rate of concordance with three chest pain related standards from the two guidelines. Nonetheless, CALD patients spent a longer time in ED compared to the Australian-born group.

Prehospital factors associated with an acute life-threatening condition in non-traumatic chest pain patients - A systematic review

BACKGROUND

Chest pain is a common symptom among patients contacting the emergency medical services (EMS). Risk stratification of these patients is warranted before arrival in hospital, regarding likelihood of an acute life-threatening condition (LTC).

AIM

To identify factors associated with an increased risk of acute LTC among patients who call the EMS due to non-traumatic chest pain.

METHODS

Several databases were searched for relevant articles. Identified articles were quality-assessed using the Scottish Intercollegiate Guidelines Network checklists. Extracted data was analysed using a semi-quantitative synthesis evaluating the level of evidence of each identified factor.

RESULTS

In total, 10 of 1245 identified studies were included. These studies provided strong evidence for an increased risk of an acute LTC with increasing age, male gender, elevated heart rate, low systolic blood pressure and ST elevation or ST depression on a 12-lead ECG. The level of evidence regarding the history of myocardial infarction, angina pectoris or presence of a Q wave or a Left Bundle Branch Block on the ECG was moderate. The evidence was inconclusive regarding dyspnoea, cold sweat/paleness, nausea/vomiting, history of chronic heart failure, smoking, Right Bundle Branch Block or T-inversions on the ECG.

CONCLUSIONS

Factors reflecting age, gender, myocardial ischemia and a compromised cardiovascular system predicted an increased risk of an acute life-threatening condition in the prehospital setting in cases of acute chest pain. These factors may form the basis for prehospital risk stratification in acute chest pain.

Could ten questions asked by the dispatch center predict the outcome for patients with chest discomfort?

BACKGROUND AND AIMS

From 2009 to 2010, approximately 14,000 consecutive persons who called for the EMS due to chest discomfort were registered. From the seventh month, dispatchers ask 2285 patient ten pre-specified questions. We evaluate which of these questions was independently able to predict an acute coronary syndrome (ACS), life-threatening condition (LTC) and death.

METHODS

The questions asked mainly dealt with previous history and type of symptoms, each with yes/no answers. The dispatcher took a decision on priority; 1) immediately with sirens/blue light; 2) EMS on the scene within 30min; 3) normal waiting time.We examined the relationship between the answers to these questions and subsequent dispatch priority, as well as outcome, in terms of ACS, LTC and all-cause mortality.

RESULTS

2285 patients (mean age 67years, 49% women) took part, of which 12% had a final diagnosis of ACS and 15% had a LTC. There was a significant relationship between all the ten questions and the priority given by dispatchers. Localisation of the discomfort to the center of the chest, more intensive pain, history of angina or myocardial infarction as well as experience of cold sweat were the most important predictors when evaluating the probability of ACS and LTC. Not breathing normally and having diabetes were related to 30-day mortality.

CONCLUSIONS

Among individuals, who call for the EMS due to chest discomfort, the intensity and the localisation of the pain, as well as a history of ischemic heart disease, appeared to be the most strongly associated with outcome.

Why and when citizens call for emergency help: an observational study of 211,193 medical emergency calls

BACKGROUND

A medical emergency call is citizens' access to pre-hospital emergency care and ambulance services. Emergency medical dispatchers are gatekeepers to provision of pre-hospital resources and possibly hospital admissions. We explored causes for access, emergency priority levels, and temporal variation within seasons, weekdays, and time of day for emergency calls to the emergency medical dispatch center in Copenhagen in a two-year study period (December 1(st), 2011 to November 30(th), 2013).

METHODS

Descriptive analysis was performed for causes for access and emergency priority levels. A Poisson regression model was used to calculate adjusted ratio estimates for the association between seasons, weekdays, and time of day overall and stratified by emergency priority levels.

RESULTS

We analyzed 211,193 emergency calls for temporal variation. Of those, 167,635 calls were eligible for analysis of causes and emergency priority level. "Unclear problem" was the most frequent category (19%). The five most common causes with known origin were categorized as "Wounds, fractures, minor injuries" (13%), "Chest pain/heart disease" (11%), "Accidents" (9%), "Intoxication, poisoning, drug overdose" (8%), and "Breathing difficulties" (7%). The highest emergency priority levels (Emergency priority level A and B) were assigned in 81% of calls. In the analysis of temporal variation, the total number of calls peaked at wintertime (26%), Saturdays (16%), and during daytime (39%).

CONCLUSION

The pattern of citizens' contact causes fell into four overall categories: unclear problems, medical problems, intoxication and accidents. The majority of calls were urgent. The magnitude of unclear problems represents a modifiable factor and highlights the potential for further improvement of supportive dispatch priority tools or educational interventions at dispatch centers. Temporal variation was identified within seasons, weekdays and time of day and reflects both system load and disease occurrence. Data on contact patterns could be utilized in a public health perspective, benchmarking of EMS systems, and ultimately development of best practice in the area of emergency medicine.

A Review of Current Diagnosis, Investigation, and Management of Acute Coronary Syndromes in Elderly Patients

The elderly constitute a sizeable proportion of the acute coronary syndrome (ACS) population, and this population is continually increasing in number. Guideline-directed therapy is frequently underutilized in the elderly due to concerns about patient safety. However, studies suggest that this subgroup could benefit from many of the conventional and newer therapies available. This paper reviews current literature in the context of contemporary American and European guidance.

Outcomes of patients calling emergency medical services for suspected acute cardiovascular disease

Adequate health care is increasingly dependent on prehospital systems and cardiovascular (CV) disease remains the most common cause for hospital admission. However the prevalence of CV dispatches of emergency medical services (EMS) is not well reported and survival data described in clinical trials and registries are subject to selection biases. We aimed to describe the prevalence and prognosis of acute CV disease and the effect of invasive treatment, in an unselected and consecutive prehospital cohort of 3,410 patients calling the national emergency telephone number from 2005 to 2008 with follow-up in 2013. Individual-level data from national registries were linked to the dedicated EMS database of primary ambulance dispatches supported by physician-manned emergency units. Outcome data were obtained from the Central Population Registry, the National Patient Registry, and the National Registry of Causes of Death. In patients calling the national emergency telephone number, a CV related ambulance alarm code was given in 2,541 patients of 3,410 patients (74.5%) resulting in 2,056 of 3,410 primary CV discharge diagnoses (60.3%) with a 30-day and 5-year all-cause mortality of 24.5% and 46.4%, respectively. Stroke, acute heart failure, and ST-segment elevation myocardial infarction (STEMI) carried a 25- to 50-fold adjusted mortality hazard during the first 4 days. In patients with suspected STEMI, 90.5% had an acute angiography performed. Nontransferred, nonreperfused patients with STEMI (9.1%) carried 80% short-term mortality. Noninvasive management of non-ST-segment elevation myocardial infarction was common (37.9%) and associated with an increased adjusted long-term mortality hazard (hazard ratio 4.17 [2.51 to 8.08], p <0.001). Survival in 447 out-of-hospital cardiac arrest patients (13.1%) was 11.6% at 30 days. In conclusion, patients with a CV ambulance alarm call code and a final CV discharge diagnosis constitute most patients handled by EMS with an extremely elevated short-term mortality hazard and a poor long-term prognosis. Although co-morbidities and frailty may influence triage, this study emphasizes the need for an efficient prehospital phase with focus on CV disease and proper triage of patients suitable for invasive evaluation if the outcomes of acute heart disease are to be improved further in the current international context of hospitals merging into highly specialized entities resulting in longer patient transfers.