Outcomes from out-of-hospital cardiac arrest in Detroit.

OBJECTIVE: To determine the out-of-hospital cardiac arrest survival rate, and prevalence of modifiable factors associated with survival, in Detroit, Michigan, over a 6-month period of time in 2002. METHODS: A retrospective review of all out-of-hospital cardiac arrests responded to by the Detroit Fire Department, Division of Emergency Medical Services. All elements of the EMS runsheet were transcribed to a database for analysis. Patient hospital records were reviewed to determine survival to hospital admission. All survivors to hospital admission were surveyed later in the Michigan Department of Vital Records death registry search. RESULTS: During this study timeframe, there were 538 confirmed out-of-hospital cardiac arrests within the City of Detroit, of which 67 were excluded for being dead on scene [51 (12.5%)] or having no available hospital records [16 (3.0%)]. Of the remaining 471 patients, 443 (94.1%) died before hospital admission. Only 44 (9.9%) of the 471 patients had a first recorded rhythm of ventricular fibrillation (VF), and 339 (76.5%) were asystolic. Of the 28 patients who survived to hospital admission, only 2 (7.1%) were noted to have a first rhythm of VF, and 15 (53.6%) were asystolic. Only one patient survived to hospital discharge. CONCLUSIONS: In this urban setting, out-of-hospital cardiac arrest is an almost uniformly fatal event.

Aminophylline in the treatment of acute asthma when beta 2-adrenergics and steroids are provided.

BACKGROUND: The purpose of this study was to test the contribution of aminophylline in improving peak expiratory flow rate (PEFR) during emergency department treatment of acute asthma when metaproterenol sulfate and steroid therapy are also provided. METHODS: In a prospective, randomized, double-blind, and placebo-controlled trial at a municipal hospital emergency department, 44 patients with acute asthma, aged 18 to 45 years, with theophylline levels below 28 mumol/L, who had failed to achieve a PEFR of 40% predicted after one nebulized metaproterenol treatment, were recruited. An aminophylline or placebo loading dose and maintenance infusion were administered. All patients received hourly nebulized metaproterenol and initial methylprednisolone sodium succinate. The PEFR was measured hourly for 5 hours. Two-factor repeated-measures analysis of variance of improvement in PEFR ([final-initial PEFR]/predicted PEFR) was assessed. RESULTS: There was no difference in improvement of PEFR at any hour between the treatment and placebo groups. After 5 hours, the difference in improvement ratio was 0.40 (aminophylline) vs 0.36 (placebo) (P = .30; n = 22 in each group). The treatment group suffered more tremor, nausea or vomiting, and palpitations (P < .05). CONCLUSION: In the emergency department setting, aminophylline contributes no significant improvement in PEFR when beta 2-agonists and corticosteroids are being provided, while causing more side effects.

An evaluation of a chest pain diagnostic protocol to exclude acute cardiac ischemia in the emergency department.

BACKGROUND: Although accelerated diagnostic protocols are being increasingly used in emergency departments to diagnose acute cardiac ischemia, there have been no prospective evaluations of a chest pain diagnostic protocol with serial determinations of creatine kinase MB isoenzyme and mandatory exercise electrocardiography (ExECG). METHODS: Prospective cross-sectional study in which chest pain protocol results were compared with final (reference) diagnoses of acute cardiac ischemia (including acute myocardial infarction and unstable angina). Patients in need of hospital admission but at low probability (by a validated algorithm) for acute myocardial infarction were examined for exclusions: known coronary artery disease, cardiac complications, severe comorbidities, or inability to perform exercise testing. A 12-hour diagnostic protocol included serial measurements of creatine kinase MB, ECG, and clinical assessments followed by ExECG for those with negative initial serial testing. Reference diagnoses were established during hospitalization and diagnostic accuracy was assessed. RESULTS: The study group of 317 patients was 54% male and 65% black, and had a mean age of 46.6 years; 9.5% had a final diagnosis of acute cardiac ischemia. For this diagnosis, the protocol had a sensitivity of 90.0% (95% confidence interval, 72.3%-97.4%); specificity, 50.5% (95% confidence interval, 44.6%-56.4%); positive predictive value, 16.0%; and negative predictive value, 98.0%. Creatine kinase MB, serial ECGs, and ExECG each made a contribution to improved sensitivity and accuracy, whereas clinical reassessments were less discriminating, as indicated by protocol's receiver operating characteristic curve. CONCLUSIONS: A chest pain diagnostic protocol achieved high sensitivity and improved specificity over the standard emergency department workup. There were no adverse advents associated with early ExECG.

A comparison between emergency diagnostic and treatment unit and inpatient care in the management of acute asthma.

BACKGROUND: Emergency diagnostic and treatment units (EDTUs) may provide an alternative to hospitalization for patients with reversible diseases, such as asthma, who fail to adequately respond to emergency department therapy. OBJECTIVE: To evaluate the medical and cost-effectiveness, patient satisfaction, and quality of life of patients receiving EDTU care for acute asthma compared with inpatient care. METHODS: A prospective, randomized clinical trial performed at 2 urban public hospitals enrolled patients with acute asthma (age range, 18-55 years) not meeting discharge criteria after 3 hours of emergency department therapy. Patients were treated with inhaled adrenergic agonists and steroids in an EDTU for up to 9 hours after randomization or with routine therapy in a hospital ward. Patients were followed up for 8 weeks. MAIN OUTCOME MEASURES: Discharge rate from the EDTU, length of stay, relapse rates, days missed from work or school, days incapacitated during waking hours, symptom-free days and nights, nocturnal awakenings, direct medical costs, patients satisfaction, and patient quality of life. RESULTS: The study consisted of 222 patients with asthma. Sixty-five patients (59%) treated in an EDTU were discharged home; the remainder were admitted to the hospital. There were no differences during the follow-up period in relapse rates (P = .74) or in any other morbidities between the EDTU and inpatient groups. There were significant differences in the length of stay, patient satisfaction, and quality of life favoring EDTU care. The mean (+/-SD) cost per patient in the EDTU group was $1202.79 +/- $1343.96, compared with $2247.32 +/- $1110.18 for the control group (P < .001). CONCLUSIONS: Treatment of selected patients with asthma in an EDTU results in the safe discharge of most such patients. This study suggests that quality gains and cost-effective measures can be achieved by the use of such units.

Risk of human immunodeficiency virus infection among emergency department workers.

PURPOSE: To estimate (1) the prevalence of human immunodeficiency virus (HIV) infection in emergency department (ED) patients, (2) the frequency of blood contact (BC) in ED workers (EDWs), (3) the efficacy of gloves in preventing BC, and (4) the risk of HIV infection in EDWs due to BC. PATIENTS AND METHODS: We conducted an 8-month study in three pairs of inner-city and suburban hospital EDs in high AIDS incidence areas in the United States. At each hospital, blood specimens from approximately 3,400 ED patients were tested for HIV antibody. Observers monitored BC and glove use by EDWs. RESULTS: HIV seroprevalence was 4.1 to 8.9 per 100 patient visits in the 3 inner-city EDs, 6.1 in 1 suburban ED, and 0.2 and 0.7 in the other 2 suburban EDs. The HIV infection status of 69% of the infected patients was unknown to ED staff. Seroprevalence rates were highest among patients aged 15 to 44 years, males, blacks and Hispanics, and patients with pneumonia. BC was observed in 379 (3.9%) of 9,793 procedures; 362 (95%) of the BCs were on skin, 11 (3%) were on mucous membranes, and 6 (2%) were percutaneous. Overall procedure-adjusted skin BC rates were 11.2 BCs per 100 procedures for ungloved workers and 1.3 for gloved EDWs (relative risk = 8.8; 95% confidence interval = 7.3 to 10.3). In the high HIV seroprevalence EDs studied, 1 in every 40 full-time ED physicians or nurses can expect an HIV-positive percutaneous BC annually; in the low HIV seroprevalence EDs studied, 1 in every 575. The annual occupational risk of HIV infection for an individual ED physician or nurse from performing procedures observed in this study is estimated as 0.008% to 0.026% (1 in 13,100 to 1 in 3,800) in a high HIV seroprevalence area and 0.0005% to 0.002% (1 in 187,000 to 1 in 55,000) in a low HIV seroprevalence area. CONCLUSIONS: In both inner-city and suburban EDs, patient HIV seroprevalence varies with patient demographics and clinical presentation; the infection status of most HIV-positive patients is unknown to ED staff. The risk to an EDW of occupationally acquiring HIV infection varies by ED location and the nature and frequency of BC; this risk can be reduced by adherence to universal precautions.

A national survey of emergency department chest pain centers in the United States.

Although chest pain centers are promoted as improving emergency cardiac care, no data exist on their structure and processes. This national study determines the 1995 prevalence rate for emergency department (ED)-based chest pain centers in the United States and compares organizational differences of EDs with and without such centers. A mail survey was directed to 476 EDs randomly selected from the American Hospital Association's database of metropolitan hospitals (n = 2,309); the response rate was 63%. The prevalence of chest pain centers was 22.5% (95% confidence interval 18% to 27%), which yielded a projection of 520 centers in the United States in 1995. EDs with centers had higher overall patient volumes, greater use of high-technology testing, lower treatment times for thrombolytic therapy, and more advertising (all p <0.05). Hospitals with centers had greater market competition and more beds per annual admissions, cardiac catheterization, and open heart surgery capability (all p <0.05). Logistic regression identified open heart surgery, high-admission volumes, and nonprofit status as independent predictors of hospitals having chest pain centers. Thus, chest pain centers have a moderate prevalence, offer more services and marketing efforts than standard EDs, and tend to be hosted by large nonprofit hospitals.

Value of posterior and right ventricular leads in comparison to the standard 12-lead electrocardiogram in evaluation of ST-segment elevation in suspected acute myocardial infarction.

In this multicenter prospective trial, we studied posterior (V7 to V9) and right ventricular (V4R to V6R) leads to assess their accuracy compared with standard 12-lead electrocardiograms (ECGs) for the diagnosis of acute myocardial infarction (AMI). Patients aged >34 years with suspected AMI received posterior and right ventricular leads immediately after the initial 12-lead ECG. ST elevation of 0.1 mV in 2 leads was blindly determined and inter-rater reliability estimated. AMI was diagnosed by World Health Organization criteria. The diagnostic value of nonstandard leads was determined when 12-lead ST elevation was absent and present and multivariate stepwise regression analysis was also performed. Of 533 study patients, 64.7% (345 of 533) had AMI and 24.8% received thrombolytic therapy. Posterior and right ventricular leads increased sensitivity for AMI by 8.4% (p = 0.03) but decreased specificity by 7.0% (p = 0.06). The likelihood ratios of a positive test for 12, 12 + posterior, and 12 + right ventricular ECGs were 6.4, 5.6, and 4.5, respectively. Increased AMI rates (positive predictive values) were found when ST elevation was present on 6 nonstandard leads (69.1%), on 12 leads only (88.4%), and on both 6 and 12 leads (96.8%; p <0.001). Treatment rates with thrombolytic therapy increased in parallel with this electrocardiographic gradient. Logistic regression analysis showed that 4 leads were independently predictive of AMI (p <0.001): leads I, II, V3, V5R; V9 approached statistical significance (p = 0.055). The standard ECG is not optimal for detecting ST-segment elevation in AMI, but its accuracy is only modestly improved by the addition of posterior and right ventricular leads.

Prediction of relapse within eight weeks after an acute asthma exacerbation in adults.

Associations between historical, presenting, and treatment-related characteristics and relapse within 8 weeks after a moderate to severe asthma exacerbation were studied in a cohort of 284 adult asthmatics. Data were collected prospectively, and a multivariate model was developed and internally validated. Within 10 days, only 8% had relapsed, increasing to 45% by 8 weeks. Three variables that could be identified at the time of discharge were independently associated with relapse. These included: having made three or more visits to an emergency department in the prior 6 months (hazard ratio (HR) = 2.3, 95% CI = 1.6-3.4); difficulty performing work or activities as a result of physical health in the 4 weeks prior (HR = 2.7, 95% CI = 1.6-4.3); discontinuing hospital-based treatment for the exacerbation within 24 hours without having achieved a peak expiratory flow rate of at least 50% of predicted (HR = 2.6, 95% CI = 1.6-4.1). These risk factors may help to identify patients with poorly controlled asthma in need of more intensive and comprehensive management.

An evaluation of research training in a large residency program.

OBJECTIVE: Evaluation of a research training program for emergency medicine residents. METHODS: A cross-sectional, descriptive analysis of knowledge and skill acquisition observed following the introduction of a resident research curriculum was performed at a university-affiliated emergency medicine residency program within a large-volume, inner-city hospital. The didactic program was based upon a published SAEM model research curriculum and included tutorials in computer applications for research. Seventeen first-year residents participated in the new curriculum and self-assessment evaluation. The rate of research proposal preparation after curriculum implementation for the 17 course participants was compared with that of 26 historical control subjects from the same residency program. RESULTS: Resident attendance for the sessions, offered twice annually, averaged 82%. Significant self-perceived knowledge gains (p < 0.05) were found in the areas of study design and methods, journal selection, research planning, and two microcomputer application areas. There was a strong correlation between postcourse examination scores for many specific subject areas and attendance at the related sessions. Thirteen of the 17 participants (76%) completed an original (NIH PHS398-formatted) research proposal within four months following the training program, compared with only six of 26 residents (23%) not exposed to such a curriculum in previous years (p < 0.05). CONCLUSION: Residents appeared satisfied with this level of training and made gains in their skills and knowledge of research activities. The rate of preparation of research proposals by course attendees surpassed that of former residents. This educational intervention may augment the standard practice of faculty mentorship of residents and fellows for research knowledge and skill acquisition.

Predicting recovery from acute asthma in an emergency diagnostic and treatment unit.

OBJECTIVE: Optimal use of emergency diagnostic and treatment unit (EDTU) resources for treatment of acute asthma should be facilitated by the selection of patients with a high probability of discharge from the EDTU. The study goal was to identify characteristics of the patient or exacerbation that could be used to predict recovery of pulmonary function within 12 hours. METHODS: Comprehensive cohort design in an urban public hospital. The subjects were 269 patients with moderately severe asthma exacerbations. Data were collected for historical and presenting features and response to treatment over 12 hours. Two outcomes were examined: 1) discharge from the EDTU and 2) achieving 50% predicted peak expiratory flow rate (PEFR) within 12 hours. RESULTS: The two outcomes showed good concordance. The third-treatment PEFR was found to be predictive of both discharge and reaching 50% predicted PEFR within 12 hours. Since the objective measure of reaching 50% predicted PEFR is more readily defined and thus more generalizable, the authors focused on this outcome when describing prediction zones. Patients with 40% or higher PEFR after third treatment had an 89% probability of reaching 50% predicted in 12 hours, while those with a third-treatment PEFR lower than 32% predicted had only a 22% probability. CONCLUSIONS: A simple objective measure of pulmonary function early in treatment discriminated among those with high, low, and intermediate probabilities of achieving a specified level of PEFR within 12 hours. Awareness of this probability could assist clinicians attempting to predict discharge from the EDTU and facilitate decision making regarding utilization of EDTU resources.

Funding strategies for emergency medicine research.

The importance of adequate funding for sustaining research efforts cannot be overemphasized. This article addresses funding strategies for emergency physicians, including the necessity of establishing a research track record, developing a well-written grant proposal, and anticipating the grant review process. Funding sources are reviewed with an emphasis on federal institute support and private foundations (including the Emergency Medicine Foundation) in the United States. Sources of current grant support information available from the Internet are provided. Recommendations for enhancing research funding in emergency medicine (EM) are made, including enhancement of formal research training, promotion of EM research and investigators, federal study section membership, and collaboration with established investigators.

Impact of technetium-99m sestamibi imaging on the emergency department management and costs in the evaluation of low-risk chest pain.

OBJECTIVES: To assess the impact of rest sestamibi scanning on emergency physicians' (EPs') diagnostic certainty and decision making (as assessed by the hypothetical disposition of patients) for 69 consenting stable patients with suspected acute cardiac ischemia and nondiagnostic electrocardiograms. The resultant impact on costs was examined as a secondary outcome. METHODS: Patients with suspected acute cardiac ischemia were injected with 25 mCi of sestamibi within two hours of active pain in one of three emergency department study sites. The probability of acute myocardial infarction (AMI) and unstable angina (UA), and hypothetical disposition decisions were recorded immediately before and after physicians were notified of scan results. Changes in disposition were classified as optimal or suboptimal. For the cost determinations, a cost-based decision support program was used. RESULTS: For the subgroup found to be free of acute cardiac events (ACEs) (n = 62), the EPs' post-sestamibi scan probabilities for AMI decreased by 11% and UA by 18% (p < 0.001 for both conditions). In seven patients with ACEs, the post-scan probabilities of AMI and UA increased, but neither was statistically significant. Scan results led to hypothetical disposition changes in 29 patients (42%), of which 27 (93%) were optimal (nine patients were reassigned to a lower level of care, two to a higher level, and 16 additional patients to "discharge-home" status). The strategy of scanning all patients who were low to moderate risk for acute cardiac ischemia would result in an increase of direct costs of care of $222 per patient evaluated, due to added cost of sestamibi scanning. CONCLUSIONS: Sestamibi scanning results appropriately affected the EPs' estimates of the probability of AMI and UA and improved disposition decisions. Scanning all low-risk patients would likely be associated with increased costs at this medical center.

The emergency department electrocardiogram and hospital complications in myocardial infarction patients.

OBJECTIVE: To determine whether acute myocardial infarction (AMI) patients who have negative ECGs on presentation have significantly lower complication rates than do those AMI patients who have positive ECGs on presentation. METHODS: Retrospective, cohort analysis comparing rates of hospital complications (ventricular fibrillation or tachycardia, shock, atrial arrhythmia or bradyarrhythmia with systolic blood pressure < or = 90 mm Hg, pulmonary edema) or interventions among patients with a final hospital diagnosis of AMI and an initially negative vs positive ECG. A negative ECG was normal or had nonspecific ST-segment and/or T-wave abnormalities (upright, flattened T waves; an isolated inverted T wave; ST depression < 0.1 mV; tall T waves with J-point elevation) or minor nonischemic abnormalities. Sample size was adequate to detect a 30% between-group difference in complication rates [alpha = 0.05, 1 - beta (power) = 0.80]. RESULTS: The 27 negative-ECG AMI patients differed from the 38 control patients in (mean +/- SD) age [57 +/- 12 vs 66 +/- 12 years, p < 0.01] but not in gender or history of AMI. The negative- and positive-ECG groups had similar rates of hospital complications [30% (95% CI: 13-47%) vs 42% (95% CI: 26-58%), p = 0.44] and intensive procedures [19% (95% CI: 4-34%) vs 29% (95% CI: 15-43%), p = 0.50], respectively. The negative-ECG patients with hospital complications had ECG evolution precede the event in 83% (95% CI: 69-97%) of cases; persistently negative-ECG patients had no complications [(95% CI: 0-33%), p = 0.06]. CONCLUSIONS: Negative- and positive-ECG AMI patients do not have moderate or large differences in the rates of in-hospital complications. Most negative-ECG patients who suffer complications evolve ECG changes prior to the event and such changes indicate the potential need for a higher level of care.

Patient satisfaction with an emergency department asthma observation unit.

OBJECTIVE: To compare levels of patient satisfaction between the diagnostic and treatment protocols in an ED-based asthma observation unit (AOU) and those with standard inpatient hospitalization. METHODS: This was a prospective, randomized, controlled trial with a sample of 163 patients presenting to the ED with acute asthma exacerbations over a 30-month period. Eligible patients were those who could not resolve their symptoms after three hours of standard ED therapy. Patients were then randomly assigned to an ED-based AOU (experimental group) or to customary inpatient care (control group). Patient satisfaction and problems with care processes were assessed by standardized instrumentation at discharge in both groups. RESULTS: The AOU patients scored higher than those randomized to the inpatient hospitalization protocol on four summary ratings of patient satisfaction measures: received service wanted, recommendation of the service to others, satisfaction with the service, and overall satisfaction. The AOU patients reported fewer total number of problems with care received, and fewer specific problems with communication, emotional support, physical comfort, and special needs, than did the inpatient group. However, the AOU patients reported more problems regarding their knowledge of financial costs and liabilities for their service than did the inpatients. CONCLUSION: Patients were more satisfied and had fewer problems with rapid diagnosis and treatment in the AOU than they did with routine inpatient hospitalization. Since AOUs represent a new ambulatory service modality, patients would benefit from greater awareness of the costs and coverage for AOUs as compared with hospital inpatient care. These findings have important implications for the future short- and long-term success and feasibility of ED-based AOUs.

Resting sestamibi imaging for the prognosis of low-risk chest pain.

OBJECTIVE: To assess the prognostic value of resting Tc-99m sestamibi scanning for adverse cardiac events (ACEs) in ED chest pain patients with a low probability of acute cardiac ischemia (ACI). METHODS: Sixty-nine consenting, hemodynamically stable patients with chest pain and a nondiagnostic electrocardiogram received an injection of 25 mCi of sestamibi during or within two hours of active pain. Scans were interpreted locally by a nuclear cardiologist or radiologist. Interrater reliability was assessed. ACEs of myocardial infarction (MI), death, or revascularization were assessed during the index hospitalization and over a one-year follow-up period. RESULTS: For ACEs, rest scanning with sestamibi had a sensitivity of 71% (95% CI = 0.33 to 0.97), a specificity of 92% (95% CI = 0.82 to 0.97), and an accuracy of 90% (95% CI = 0.87 to 0.99). The positive predictive value was 50% (95% CI = 0.19 to 0.82) and the negative predictive value was 97% (95% CI = 0.87 to 0.98). Sestamibi scanning was highly discriminating, with 62% of patients with positive scans but only 3% with negative scans having ACEs (p<0.001, log rank test). CONCLUSION: In patients with low-risk chest pain, sestamibi scanning has good specificity and moderate sensitivity for ACEs over a 12-month period.

The chest pain center in the emergency department.

Despite the improvement of medical treatment for acute coronary syndromes throughout the 20th century, the authors believe that many cases of life-threatening coronary events could be avoided through early detection of CAD and the use of preventive strategies. Establishing chest pain units that are linked to the ED is one excellent strategy to risk-stratify patients with symptoms who are at risk for sustaining an AMI or having lethal arrhythmias. There is a need for more research on chest pain units to determine the value for cost and to further optimize strategies for ACI detection and screening. In EDs with high volumes of chest pain patients, or high pressures to avoid hospital admissions, a planned, systematic, and rapid approach to the treatment of AMI and the diagnosis of chest pain is a rewarding necessity.

Stress testing for risk stratification of patients with low to moderate probability of acute cardiac ischemia.

In summary, this article focused on the use of stress testing to risk-stratify patients at the conclusion of their emergency evaluation for ACI. As discussed, those patients in the probably not ACI category require additional risk stratification prior to discharge. It should be kept in mind that patients in this category are heterogeneous, containing subgroups at both higher and lower risk of ACI and cardiac events. The patients with lower pretest probability for ACI may only need exercise testing in the ED. Patients with higher pretest probability should undergo myocardial perfusion or echocardiographic stress testing to maximize diagnostic and prognostic information. Prognostic information is the key to provocative testing in the ED. Prognostic information is the component that will help emergency physicians identify the patients who may be discharged home safely without having to worry about a 6% annual cardiac death rate and a 10% overall death rate over the next 30 months. Stress testing provides this key prognostic data, and it can be obtained in short-stay chest pain observation units in a safe, timely, and cost-effective fashion.

Evaluation and risk stratification of patients with chest pain in the emergency department. Predictors of life-threatening events.

While assessing chest pain in the emergency department, physicians must first estimate the probability of acute ischemic states in the patient. This first estimate is based on the patient's history, physical examination, and electrocardiogram. Patients who meet the threshold for acute cardiac ischemia are further evaluated to confirm or exclude this diagnosis, while other life-threatening factors are excluded.

Safety evaluation and confidence intervals when the number of observed events is small or zero.

A common objective in many clinical studies is to determine the safety of a diagnostic test or therapeutic intervention. In these evaluations, serious adverse effects are either rare or not encountered. In this setting, the estimation of the confidence interval (CI) for the unknown proportion of adverse events has special importance. When no adverse events are encountered, commonly used approximate methods for calculating CIs cannot be applied, and such information is not commonly reported. Furthermore, when only a few adverse events are encountered, the approximate methods for calculation of CIs can be applied, but are neither appropriate nor accurate. In both situations, CIs should be computed with the use of the exact binomial distribution. We discuss the need for such estimation and provide correct methods and rules of thumb for quick computations of accurate approximations of the 95% and 99.9% CIs when the observed number of adverse events is zero.