Ambulance despatchers' estimation of intensity of pain and presence of associated symptoms in relation to outcome in patients who call for an ambulance because of acute chest pain

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.

Acute coronary syndrome in relation to the occurrence of associated symptoms: A quantitative study in prehospital emergency care

INTRODUCTION

Acute chest pain is a common symptom among prehospital emergency care patients. Therefore, it is crucial that ambulance nurses (ANs) have the ability to identify symptoms and assess patients suffering from acute coronary syndrome (ACS). The aim of this study is to explore the occurrence of dyspnoea and nausea and/or vomiting in the prehospital phase of a suspected ACS and the associations with patients' outcome.

METHODS

This study has a quantitative design based on data from hospital records and from a previous interventional study (randomised controlled trial) including five Emergency Medical Service (EMS) systems in western Sweden in the years 2008-2010.

RESULTS

In all, 1836 patients were included in the interventional study. Dyspnoea was reported in 38% and nausea and/or vomiting in 26% of patients. The risk of death within one year increased with the presence of dyspnoea. The presence of nausea and/or vomiting increased the likelihood of a final diagnosis of acute myocardial infarction (AMI).

CONCLUSION

This study shows that dyspnoea, nausea and/or vomiting increase the risk of death and serious diagnosis among ACS patients. This means that dyspnoea, nausea and/or vomiting should influence the ANs' assessment and that special education in cardiovascular nursing is required.

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.

Chest pain in an out-of-hospital emergency setting: no relationship between pain severity and diagnosis of acute myocardial infarction

BACKGROUND

Chest pain frequently prompts emergency medical services (EMS) call-outs. Early management of acute coronary syndrome (ACS) cases is crucial, but there is still controversy over the relevance of pain severity as a diagnostic criterion.

STUDY OBJECTIVE

The aim of this study was to determine whether there is a relationship between the severity of chest pain at the time of out-of-hospital emergency care and diagnosis of acute myocardial infarction (AMI).

METHODS

This was a subsidiary analysis of prehospital data collated prospectively by EMS in a large suburb. It concerned patients with chest pain taken to hospital by a mobile intensive care unit. Pain was rated on EMS arrival using a visual analog, numeric or verbal rating scale and classified on severe or not severe according to the pain score. A diagnosis of AMI was confirmed or ruled out on the basis of 2 plasma troponin measurements and/or coronary angiography results.

RESULTS

Among the cohort of 2,279 patients included, 234 were suitable for analysis, of which 109 (47%) were diagnosed with AMI. The rate of severe pain on EMS arrival was not significantly different between AMI patients and no myocardial infarction patients (49% [95% CI 40 to 58] and 43% [34 to 52], respectively; P = 0.3; odds ratio 1.3 [0.8 - 2.3] after adjustment for age and gender).

CONCLUSION

In our out-of-hospital emergency setting, the severity of chest pain was not a useful diagnostic criterion for AMI.

Presenting symptoms of myocardial infarction predict short- and long-term mortality: the MONICA/KORA Myocardial Infarction Registry

BACKGROUND

It is unknown whether clinical outcomes differ with specific symptoms of an acute myocardial infarction (AMI). The objective of this study was to investigate the association between 13 self-reported symptoms and 28-day case fatality or long-term all-cause mortality in patients with AMI.

METHODS

The sample consisted of 1,231 men and 415 women aged 25 to 74 years hospitalized with a first-time AMI recruited from a population-based AMI registry. Multivariable logistic regression modeling was used to assess the relationship between symptom occurrence and 28-day case fatality. Cox proportional hazards models were used to determine the effects on long-term mortality. Analyses were adjusted for sex, age, type of AMI, diabetes, prehospital delay time, and reperfusion therapy.

RESULTS

The median observation time was 4.1 years (interquartile range 15 years). Twenty-eight-day case fatality was 6.1%, and long-term mortality was 10.6%. Patients who experienced fear of death (odds ratio [OR] 0.11, 95% confidence interval [CI] 0.03-0.47), diaphoresis (OR 0.45, 95% CI 0.25-0.82), or nausea (OR 0.45, 95% CI 0.22-0.95) had a significantly decreased risk of dying within 28 days, whereas syncope (OR 5.36, 95% CI 2.65-10.85) was associated with a higher risk. A decreased risk for long-term mortality was found for people with pain in the upper abdomen (hazard ratio 0.43, 95% CI 0.19-0.97), whereas dyspnea was related to an increased risk (hazard ratio 1.50, 95% CI 1.11-2.06). The absence of chest symptoms was associated with a 1.85-fold risk for long-term mortality (95% CI 1.13-3.03).

CONCLUSIONS

Specific symptoms are associated with mortality. Further research is required to illuminate the reasons for this finding.

Early identification and delay to treatment in myocardial infarction and stroke: differences and similarities

Background

The two major complications of atherosclerosis are acute myocardial infarction (AMI) and acute ischemic stroke. Both are life-threatening conditions characterised by the abrupt cessation of blood flow to respective organs, resulting in an infarction. Depending on the extent of the infarction, loss of organ function varies considerably.

In both conditions, it is possible to limit the extent of infarction with early intervention. In both conditions, minutes count.

This article aims to describe differences and similarities with regard to the way patients, bystanders and health care providers act in the acute phase of the two diseases with the emphasis on the pre-hospital phase.

Method

A literature search was performed on the PubMed, Embase (Ovid SP) and Cochrane Library databases.

Results

In both conditions, symptoms vary considerably. Patients appear to suspect AMI more frequently than stroke and, in the former, there is a gender gap (men suspect AMI more frequently than women).

With regard to detection of AMI and stroke at dispatch centre and in Emergency Medical Service (EMS) there is room for improvement in both conditions. The use of EMS appears to be higher in stroke but the overall delay to hospital admission is shorter in AMI. In both conditions, the fast track concept has been shown to influence the delay to treatment considerably.

In terms of diagnostic evaluation by the EMS, more supported instruments are available in AMI than in stroke. Knowledge of the importance of early treatment has been reported to influence delays in both AMI and stroke.

Conclusion

Both in AMI and stroke minutes count and therefore the fast track concept has been introduced. Time to treatment still appears to be longer in stroke than in AMI. In the future improvement in the early detection as well as further shortening to start of treatment will be in focus in both conditions. A collaboration between cardiologists and neurologists and also between pre-hospital and in-hospital care might be fruitful.

Could a computer-based system including a prevalence function support emergency medical systems and improve the allocation of life support level?

OBJECTIVES

To evaluate whether a computer-based decision support system could be useful for the emergency medical system when identifying patients with acute myocardial infarction (AMI) or life-threatening conditions and thereby improve the allocation of life support level.

METHODS

Patients in the Municipality of Göteborg who dialled the dispatch centre due to chest pain during a period of 3 months. To analyse the relationship between patient characteristics (according to a case record form used during an interview) and the response variables (AMI or life-threatening condition), multivariate logistic regression was used. For each patient, the probability of AMI/life-threatening condition was estimated by the model. We used these probabilities retrospectively to allocate advanced life support or basic life support. This model allocation was then compared with the true allocation made by the dispatchers.

RESULTS

The sensitivity, that is, the percentage of AMI patients allocated to advanced life support, was 85.7% in relation to the true allocation made by the dispatchers. The corresponding sensitivity regarding allocation made by the model was 92.4% (P=0.17). The specificity was also slightly higher for the model allocation than the dispatcher allocation. Among the 15 patients with AMI who were allocated to basic life support by the dispatchers, nine died (eight during and one after hospitalization). Among the eight patients with AMI allocated to basic life support by the model, only one patient died (in hospital) (P=0.02).

CONCLUSION

A computer-based decision support system including a prevalence function could be a valuable tool for allocating the level of life support. The case record form, however, used for the interview can be refined and a model based on a larger sample and confirmed in a prospective study is recommended.

Differences Between Men and Women in Terms of Clinical Features of ST-Segment Elevation Acute Myocardial Infarction

BACKGROUND

Many studies have examined sex-related differences in the clinical features of acute myocardial infarction (AMI). However, prospective studies are scant, and sex-related differences in symptoms of AMI remain unclear. We examined differences between men and women in terms of the clinical features of ST-segment elevation AMI.

METHODS AND RESULTS

We studied 457 patients (106 women and 351 men) with ST-segment elevation AMI who were admitted within 24 h after symptom onset. The same cardiologist interviewed all patients within 48 h after admission. Women were older than men (72 vs 62 years, p<0.001) and had higher rates of hypertension (70 vs 56%, p=0.010), diabetes mellitus (36 vs 26%, p=0.047), and hyperlipidemia (51 vs 38%, p=0.019). Women were more likely than men to have non-specific symptoms (45 vs 34%, p=0.033), non-chest pain (pain in the jaw, throat, neck, shoulder, arm, hand, and back), mild pain (20 vs 7%, p<0.001), and nausea (49 vs 36%, p=0.013). On coronary angiography, the severity of coronary-artery lesions was similar in both sexes. In-hospital mortality was significantly higher in women than in men (6.6 vs 1.4%, p=0.003).

CONCLUSIONS

Clinical profiles and presentations differ between women and men with AMI. Women have less typical symptoms of AMI than men.

Factors related to delay times in patients with suspected acute myocardial infarction

OBJECTIVE

The study's objective was to describe symptoms, symptom management, and patient delay times in patients seeking treatment for suspected acute myocardial infarction (AMI), and to find explanatory factors influencing the decision time.

METHOD

This is a descriptive survey study including 403 Swedish patients with a median age of 64 years with suspected AMI.

RESULTS

Altogether, 84% of the patients suspected that the symptoms emanated from the heart. Despite this fact, 59% delayed going to the hospital more than 1 hour after the onset of symptoms. In the multiple regression analysis, a "dull pain," the patients' belief that it was nothing serious, and contact with the general practitioner were associated with prolonged delay. The decision to contact the emergency service shortened the delay time.

CONCLUSIONS

The patient's subjective feeling of the severity of symptoms is an important predictor for delay times. There is still a need for public awareness of the appropriate responses to AMI symptoms, that is, to call for an ambulance instead of contacting the general practitioner.

Bedside diagnosis of coronary artery disease: a systematic review

PURPOSE

To assess the accuracy of bedside findings for diagnosing coronary artery disease and acute myocardial infarction.

METHODS

A MEDLINE search was performed to retrieve articles published from January 1966 to January 2003 that were relevant to the bedside diagnosis of coronary disease in adults.

RESULTS

In patients with stable, intermittent chest pain, the most useful bedside predictors for a diagnosis of coronary disease were found to be the presence of typical angina (likelihood ratio [LR]=5.8; 95% confidence interval [CI]: 4.2 to 7.8), serum cholesterol level >300 mg/dL (LR=4.0; 95% CI: 2.5 to 6.3), history of prior myocardial infarction (LR=3.8; 95% CI: 2.1 to 6.8), and age >70 years (LR=2.6; 95% CI: 1.8 to 4.0). Nonanginal chest pain (LR=0.1; 95% CI: 0.1 to 0.2), pain duration >30 minutes (LR=0.1; 95% CI: 0.0 to 0.9), and intermittent dysphagia (LR=0.2; 95% CI: 0.1 to 0.8) argued against a diagnosis of coronary disease. In patients with acute chest pain, the most important bedside predictors for a diagnosis of myocardial infarction were new ST elevation (LR=22; 95% CI: 16 to 30), new Q waves (LR=22; 95% CI: 7.6 to 62), and new ST depression (LR=4.5; 95% CI: 3.6 to 5.6). A normal electrocardiogram (LR=0.2; 95% CI: 0.1 to 0.3), chest wall tenderness (LR=0.3; 95% CI: 0.2 to 0.4), and pain that was pleuritic (LR=0.2; 95% CI: 0.2 to 0.3), sharp (LR=0.3; 95% CI: 0.2 to 0.5), or positional (LR=0.3; 95% CI: 0.2 to 0.5) argued against the diagnosis of myocardial infarction.

CONCLUSION

The accuracy of bedside predictors depends on the clinical setting. In the evaluation of stable, intermittent chest pain, a patient's description of pain was found to be the most important predictor of underlying coronary disease. In the evaluation of acute chest pain, the electrocardiogram was the most useful bedside predictor for a diagnosis of myocardial infarction. Aside from the extremes in cholesterol values, the analysis of traditional risk factors changed the probability of coronary disease or myocardial infarction very little or not at all.

Observational study of prehospital delays in patients with chest pain

OBJECTIVE

To define and measure patient reported prehospital delay in presentation to the emergency department with chest pain and identify simple strategies that may reduce this delay. The authors investigated the null hypothesis that the patients choice of service to call for acute medical help has no effect on the timing of thrombolysis.

METHOD

A prospective observational study of prehospital times and events was undertaken on a target population of patients presenting with acute chest pain attributable to an acute coronary syndrome over a three month period.

RESULTS

Patients who decided to call the ambulance service were compared with patients who contacted any other service. Most patients who contact non-ambulance services are seen by general practitioners. The prehospital system time for 121 patients who chose to call the ambulance service first was significantly shorter than for 96 patients who chose to call another service (median 57 min v 107 min; p<0.001). Of the 42 patients thrombolysed in the emergency department, those who chose to call the ambulance service had significantly shorter prehospital system times (number 21 v 21; median 44 v 69 min; p<0.001). Overall time from pain onset to initiation of thrombolysis was significantly longer in the group of patients who called a non-ambulance service first (median 130 min v 248 min; p=0.005).

CONCLUSIONS

Patient with acute ischaemic chest pain who call their general practice instead of the ambulance service are likely to have delayed thrombolysis. This is likely to result in increased mortality. The most beneficial current approach is for general practices to divert all patients with possible ischaemic chest pain onset within 12 hours direct to the ambulance service.