Prevalence of Aspirin Use among Patients Calling 9-1-1 for Chest Pain

Abstract. Objective: Early aspirin administration during an acute myocardial infarction (AMI) decreases morbidity and mortality. This investigation examined the extent to which patients with a complaint of chest pain, the symptom most identified with AMI by the general population, self-administer aspirin before the arrival of emergency medical services (EMS) personnel.
Methods: In this prospective, cross-sectional prevalence study, data were derived through the analysis of EMS incident reports for patients with a complaint of chest pain from June 1, 1997, to August 31,1997.
Results: The study included 694 subjects. One hundred two (15%) took aspirin for their chest pain before the arrival of EMS personnel. Of the 322 subjects who reported taking aspirin on a regular basis, 82 (26%) took additional aspirin for their acute chest pain. Only 20 (5%) of the 370 patients who were not using regular aspirin therapy self-administered aspirin acutely (p < 0.001). In addition, patients with lower intensity of chest pain (p = 0.03) were more likely to take aspirin for their chest pain.
Conclusion: Only a relatively small fraction of individuals calling 9-1-1 with acute chest pain take aspirin prior to the arrival of EMS personnel. These individuals are more likely to self-administer aspirin if they are already taking it on a regular basis. It is also possible that they are less likely to take aspirin if their chest pain is more severe.     

基层医院远程胸痛急救会诊终端的建设与实践

急性非创伤性胸痛具有起病急骤、病情进展快、诊断困难、可救治时间短等特点。胸痛中心和基层医院远程胸痛急救会诊终端的建立,通过早期启动和快速安全转运,提高了基层医院急诊科对急性胸痛患者的诊治效率。     

Patient and Primary Care Physician Satisfaction with Chest Pain Unit and Routine Care

OBJECTIVES: The chest pain unit (CPU) has been developed to improve care for patients with acute, undifferentiated chest pain. The authors aimed to measure patient and primary care physician (PCP) satisfaction with CPU care and routine care and to determine whether patient satisfaction predicted PCP satisfaction. METHODS: A CPU was established, and 442 days were randomly allocated to either CPU care or routine care. Consenting patients presenting with acute, undifferentiated chest pain were recruited and followed at two days and one month. All were given a self-completed patient satisfaction questionnaire two days after attendance (N = 972). Each patient's PCP was sent a self-completed satisfaction questionnaire during days 171-442 of the trial (N = 601). Analysis determined whether CPU care was associated with improved patient or PCP satisfaction and whether patient satisfaction predicted PCP satisfaction for three questions relating to diagnosis, treatment, and overall care. RESULTS: CPU care was consistently associated with higher scores across all patient satisfaction questions, from the perceived thoroughness of examination to care received to an overall assessment of the service received. However, CPU care achieved small improvements in only two of ten PCP satisfaction questions, concerning overall management of the patient and the amount of information about investigations performed. Furthermore, patient satisfaction did not predict PCP satisfaction in relation to diagnosis (p = 0.456), treatment (p = 0.256), or overall care (p = 0.085). CONCLUSIONS: CPU care is associated with substantial improvements in all dimensions of patient satisfaction but only minimal improvements in PCP satisfaction. Patient satisfaction was not a strong predictor of PCP satisfaction with emergency care.     

Emergency Department Evaluation of Chest Pain Using Exercise Stress Echocardiography

OBJECTIVE: Patients with a low risk of coronary artery disease (CAD) presenting to the emergency department (ED) with chest pain pose a diagnostic dilemma because a small percentage will suffer an acute myocardial infarction (MI) and sudden death. The authors conducted this study to determine whether exercise stress echocardiography (ESE) could be used to further support the safe discharge of these low-risk patients. METHODS: A convenience sample of patients > or =30 years of age without a prior cardiac history who presented to an academic community hospital with chest pain, normal initial creatine kinase, and electrocardiography without ischemic changes underwent ESE within 6 +/- 1.7 hours (mean +/- SD). Abnormal ESE was defined as regional wall motion abnormality at rest or after exercise. The ED disposition and three- and six-month follow-up for cardiac events were recorded. This was a prospective observational cohort study. RESULTS: Of a total of 149 eligible patients, 145 completed the study. The mean age (+/-SD) was 47 +/- 9 years; 56% were male. No adverse events were noted during ESE. Seven patients (5%) had abnormal ESE (2 with rest wall motion abnormalities and 5 with exercise-induced wall motion abnormalities). Five of the seven underwent cardiac catheterization; three had CAD. All patients received telephone follow-up at three months and six months. Of the 138 patients with a normal ESE, all were free of cardiac events at three months. One patient had a non-Q-wave MI at six months (negative predictive value = 99.3%, 95% CI = 97.8% to 100%). CONCLUSIONS: Exercise stress echocardiography can be used to evaluate low-risk chest pain patients in the ED. Patients with a normal ESE may be considered for discharge with minimal risk of sequelae.     

Prehospital Trauma Triage Decision-making: A Model of What Happens between the 9-1-1 Call and the Hospital

We describe the decision-making process used by emergency medical services (EMS) providers in order to understand how 1) injured patients are evaluated in the prehospital setting; 2) field triage criteria are applied in-practice; and 3) selection of a destination hospital is determined. We conducted separate focus groups with advanced and basic life support providers from rural and urban/suburban regions. Four exploratory focus groups were conducted to identify overarching themes and five additional confirmatory focus groups were conducted to verify initial focus group findings and provide additional detail regarding trauma triage decision-making and application of field triage criteria. All focus groups were conducted by a public health researcher with formal training in qualitative research. A standardized question guide was used to facilitate discussion at all focus groups. All focus groups were audio-recorded and transcribed. Responses were coded and categorized into larger domains to describe how EMS providers approach trauma triage and apply the Field Triage Decision Scheme. We conducted 9 focus groups with 50 EMS providers. Participants highlighted that trauma triage is complex and there is often limited time to make destination decisions. Four overarching domains were identified within the context of trauma triage decision-making: 1) initial assessment; 2) importance of speed versus accuracy; 3) usability of current field triage criteria; and 4) consideration of patient and emergency care system-level factors. Field triage is a complex decision-making process which involves consideration of many patient and system-level factors. The decision model presented in this study suggests that EMS providers place significant emphasis on speed of decisions, relying on initial impressions and immediately observable information, rather than precise measurement of vital signs or systematic application of field triage criteria.     

Heart Rate Variability Analysis in Patients Who Have Bradycardia Presenting to the Emergency Department with Chest Pain

Background

Heart rate variability (HRV) is a noninvasive method to measure the function of the autonomic nervous system. It has been used to risk stratify patients with undifferentiated chest pain in the emergency department (ED). However, bradycardia can have a modifying effect on HRV.

Measuring Quality in the Prehospital Care of Chest Pain Patients

Background. Rates of compliance with evidence-based treatment guidelines are commonly used to evaluate hospital quality of care. This method of quality assessment has not been widely extended to the prehospital environment. Previous studies have shown that the prehospital care of chest pain patients is often incomplete. Objective. To determine how well paramedics in an urban public hospital system deliver high-quality, comprehensive care for patients with nontraumatic chest pain. Methods. Patients with a primary complaint of nontraumatic chest pain for two quarters of 2006 were identified, records were randomly sampled, anda retrospective audit was performed. Seven individual quality indexes were identified by the medical director of the Denver Health Paramedic Division. A composite metric (bundle score) was also created to assess the completeness of care. This bundle score was considered unmet if any single variable was not present. Results. Five hundred eighty-six patient care reports were evaluated. Overall, 92% of the patients received oxygen, 62% received aspirin, 97% had lung sounds assessed, 99% had vital signs assessed, 84% had an intravenous (IV) line established, 92% had an electrocardiogram (ECG) obtained, and73% were assessed for cardiac risk factors. The composite score was met for only 39% of patients. Significant differences across age groups were found in assessing cardiac risk factors, obtaining ECGs, andadministering aspirin, andin the composite measure. In all of these metrics, the prehospital care rendered to the younger patients was associated with a lower rate of provider compliance than that delivered to the older patients. Conclusions. There was generally good compliance with each individual metric, yet compliance with the comprehensive metric was poor. This manner of quality assessment, utilizing a bundle score, can be successfully applied to the prehospital arena, although future work is needed to establish criteria for measuring optimal quality of care     

Differences between Chest Pain Observation Service Patients and Admitted "Rule-out Myocardial Infarction" Patients

Objective: To compare and contrast the patient characteristics of ED patients at low risk for acute cardiac ischemia who were assigned to a chest pain observation service vs those admitted to a monitored inpatient bed for "rule-out acute myocardial infarction" (R/O MI).
Methods: This was a retrospective, cross-sectional comparison of adult patients considered at relatively low risk for cardiac ischemia and who were evaluated in 1 of 2 settings: a short-term observation service and an inpatient monitored bed. All patients had an ED final diagnosis of "chest pain," "R/O MI," or "unstable angina" during the 7-month study period. Demographic features and presenting clinical features were examined as a function of site of patient evaluation.
Results: Of 531 study patients, 265 (50%) were assigned to the observation service. Younger age (OR = 1.75, 95% CI 1.26, 2.44, for each decrement of 20 years), the complaint of "chest pain" (OR = 2.35, 95% CI 1.34, 4.12), and the absence of prior known coronary artery disease (OR = 1.64, 95% CI 1.13, 2.38) were the principal independent factors associated with assignment to a chest pain observation service bed. Conclusions: Patients evaluated in a chest pain observation service appear to have different clinical characteristics than other individuals admitted to a monitored inpatient bed for "R/O MI." Investigators should address differences in clinical characteristics when making outcome comparisons between these 2 patient groups.     

Impact of the HEART Pathway on Admission Rates for Emergency Department Patients with Chest Pain: An External Clinical Validation Study

Background

Chest pain is a common emergency department (ED) chief complaint. Safe discharge mechanisms for low-risk chest pain patients would be useful.

Effect of Dial-Out Prefix Change on 9-1-1 Calls at a Large State University

Background: Accessing the emergency medical services system via 9–1-1 operators is an effective way for patients to seek urgent health care; however, technological advances and telecommunication practices inundate the 9–1-1 and emergency services infrastructure with unintentional calls that delay response efforts to legitimate medical emergencies. Objective: To determine whether the change in university-wide dial-out prefix from “9” to “7” reduced unnecessary calls to a 9–1-1 call center. Methods: This is a retrospective study conducted utilizing information obtained from the University of North Carolina at Chapel Hill (UNC) Department of Public Safety (DPS) call center. Call center calls received during pre-change, intervening, and post-change periods were included in the study. The cost savings, defined in time and money, resulting from the prefix change were also examined. Results: A total of 33,646 calls were made during the study period (January 11, 2010 through December 31, 2012) and included in the analysis. The prefix change was found to reduce the rate of invalid calls to the call center by 319 calls per month, resulting in a 43% reduction in total calls to the call center while preserving the rate of valid calls. The largest decrease occurred in hang-up calls (a decrease of 232 calls per month), especially those originating from the university. The prefix change was found to save the UNC DPS telecommunications division approximately $798.82 per month and the police officer division approximately $3,874.95 per month. Conclusion: A prefix change was not only beneficial to the UNC community but it also has potentially wide-reaching effects. A reduction of invalid 9–1-1 calls translates to telecommunicators having more time available to handle true emergencies, phone lines remaining available for true emergencies, and police officers dedicating more time and effort to matters that necessitate officer assistance. Based on the call decrease seen with the prefix change, this study may be used as evidence to advocate for a change of dial-out codes beginning with “9.”     

Performance of a Population-based Cardiac Risk Stratification Tool in Asian Patients with Chest Pain

Objectives: Most contemporary cardiac risk stratification tools have been derived and validated in mixed-race populations. Their validity in single-race populations has not been tested. The authors sought to compare the performance of a risk stratification tool between a mixed-race U.S. patient population and an Asian patient population. Methods: This study is an analysis of data from the Internet Tracking Registry for Acute Coronary Syndromes (i*tr ACS ) registry of patients with chest pain presenting to the emergency departments of eight U.S. centers and one site in Singapore. The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) was computed for included patients, and its performance in predicting acute coronary syndrome (ACS) was compared between patients from the United States and Singapore. Results: Of the 11,991 included patients, 1,120 experienced ACS. Although the ACI-TIPI demonstrated similar accuracy among groups (area under the curve, 0.729 [U.S.] vs. 0.719 [Singapore]; p = 0.5611), sensitivity and specificity were different when equal ACI-TIPI thresholds were considered. Recreating the logistic regression models used to create the ACI-TIPI showed similar results between the derived parameters and the parameters estimated for the U.S. group. In contrast, age older than 50 years (log-odds ratio [LOR], 0.107; 95% confidence interval [CI] = 0.518 to 0.713), male gender (LOR, 0.487; 95% CI = 0.149 to 1.122), and chest pain as a primary complaint (LOR, 0.237; 95% CI = 0.139 to 0.613) had little predictive power in patients from Singapore. Conclusions: Differences exist in presentation and factors associated with ACS among patients from the United States and Singapore that may affect the performance of risk stratification tools. These findings suggest that cardiac clinical decision rules need international validation.     

Variance Cardiography for Emergency Department Evaluation of Chest Pain Patients

Objective: To determine the test performance of 24–lead variance cardiography (VC), an ECG technique that measures QRS morphologic variability, for ED evaluation of chest pain associated with coronary artery disease (CAD).
Methods: A prospective, single–blind study of VC was performed in a community teaching hospital ED. All chest pain patients (>30 years of age) who, after initial emergency physician evaluation, were believed to have pain of potential cardiac etiology and were admitted to the hospital were eligible. Exclusion criteria included obvious noncardiac etiology for discomfort, bundle–branch block, atrial fibrillation, and incomplete subsequent cardiac evaluation. After initial evaluation and stabilization, VC was obtained. The numerical output of VC was a CAD index (CADI). Serum myoglobin and creatine kinase (CK)–MB levels were obtained at the time of presentation and after one, two, and six hours. Hospital records were reviewed to determine final diagnosis and in–hospital evaluation results.
Results: Fifty–two of 75 eligible patients had complete data. Final diagnoses were as follows: 27/52 (52%), noncardiac; 13/52 (25%), acute myocardial infarction (AMI); and 12/52 (23%), unstable angina due to CAD. Twenty–three percent (12/52) of the patients had CADIs < 75. Eleven of these were found to have noncardiac origins for their chest pain. The twelfth patient had a 12–lead ECG revealing AMI and had been given thrombolytic therapy with subsequent reperfusion prior to VC. Using a CADI < 75 as the cutoff for a negative study, VC alone had a negative predictive value of 92%, a sensitivity of 96%, a positive predictive value of 60%, and a specificity of 41%.
Conclusion: A CADI < 75, in addition to clinical impression and initial ECG, may identify chest pain patients who do not have significant CAD. Further prospective assessment of VC is warranted.     

基于HEART评分急性非创伤性胸痛患者分诊工具的构建

目的 通过科学的方法,构建急性非创伤性胸痛患者分诊工具,为急诊临床实践提供客观可靠的参考依据。方法 以HEART评分为理论基础,通过文献研究、分析甘肃省某三级甲等医院急性非创伤性胸痛患者回顾性资料,采用Delphi法对22名从事急诊护理管理、急危重症、心内科临床或护理工作的专家进行2轮函询,并确定指标权重。结果 2轮函询专家有效回收率均为100%,专家权威系数分别是0.931、0.832,肯德尔和谐系数分别是0.223、0.305（P<0.001）。最终形成的急性非创伤性胸痛患者分诊工具包括一级指标10项、二级指标36项。结论 急性非创伤性胸痛患者分诊工具构成合理,研究方法适用,研究结果可信度高,为急诊胸痛分诊提高效率、优化流程提供了客观依据。     

Adverse outcomes following emergency department discharge of patients with possible acute coronary syndrome

Objective: To determine the proportion of adverse events in patients discharged after ED assessment for possible acute coronary syndrome. Methods: Prospective observational cohort study enrolling consecutive patients presenting with symptoms suggestive of coronary syndrome. Main outcome was the proportion of adverse coronary events (defined a priori) within 30 days. Results: Of 2627 patients, 1819 (69%) were discharged without a diagnosis of coronary syndrome and 808 (31%) were admitted for further investigation and treatment. Of these, 385 (14.7%) were given a final diagnosis of acute coronary syndrome. On 30 day follow up, 18 of the discharged patients were diagnosed with acute coronary syndrome (0.7%; 95% confidence intervals [CI] 0.4–1.1%), 10 with unstable angina (0.4%; 95% CI 0.2–0.7%) and 8 with non‐ST elevation myocardial infarction (0.3%; 95% CI 0.2–0.6%). There were no cases of ST elevation infarction or death. The sensitivity for diagnosis of acute coronary syndromes was 95.5% (95% CI 92.9–97.3%). Average length of stay was 7 h for discharged patients. Forty‐six per cent of patients with diabetes and 47% with a past history of coronary disease were discharged. Subsequent outpatient stress testing was performed in 13.6%. Conclusions: In a large Australian ED, less than 1% of patients presenting with symptoms suggestive of coronary syndrome were discharged and subsequently had a 30 day adverse event. Reducing this proportion by admitting patients with traditional risk factors would markedly increase hospital workload. Opportunities exist to improve both the safety and efficiency of chest pain assessment in the ED.     

How Useful Are Clinical Features in the Diagnosis of Acute,Undifferentiated Chest Pain?

OBJECTIVES: To measure the predictive value and diagnostic performance of clinical features used to diagnose coronary syndromes in patients presenting with acute, undifferentiated chest pain. METHODS: The clinical features of patients presenting to the authors' chest pain unit with acute, undifferentiated chest pain were prospectively recorded on a standard form. Admitted patients were followed up by case note review. Discharged patients were followed up as outpatients three days later. Six months after the emergency department visit, evidence of adverse events was searched for from the hospital computer database, case notes, and the patient's primary care physician. The authors tested the power of each feature to predict: 1) acute myocardial infarction (AMI) by World Health Organization criteria, and 2) any acute coronary syndrome (ACS), evidenced by cardiac testing, AMI, arrhythmia, death, or revascularization procedure within six months. RESULTS: Eight hundred ninety-three patients were assessed, 34 (3.8%) with AMI and 81 (9.1%) with ACS. Features useful in the diagnosis of AMI were exertional pain [likelihood ratio (LR) = 2.35], pain radiating to the shoulder or both arms (LR = 4.07), and chest wall tenderness (LR = 0.3). Features useful in the diagnosis of ACS were exertional pain (LR = 2.06) and pain radiating to the shoulder, the left arm, or both arms (LR = 1.62). The site or nature of pain and the presence of nausea, vomiting, or diaphoresis were not predictive of AMI or ACS. CONCLUSIONS: Important differences exist when clinical features are specifically investigated in patients with acute chest pain and a nondiagnostic electrocardiogram. Clinical features have a limited role to play in triage decision making.