Prior differences in previous trauma exposure primarily drive the observed racial/ethnic differences in posttrauma depression and anxiety following a recent trauma.

BACKGROUND: Racial and ethnic groups in the USA differ in the prevalence of posttraumatic stress disorder (PTSD). Recent research however has not observed consistent racial/ethnic differences in posttraumatic stress in the early aftermath of trauma, suggesting that such differences in chronic PTSD rates may be related to differences in recovery over time. METHODS: As part of the multisite, longitudinal AURORA study, we investigated racial/ethnic differences in PTSD and related outcomes within 3 months after trauma. Participants (n = 930) were recruited from emergency departments across the USA and provided periodic (2 weeks, 8 weeks, and 3 months after trauma) self-report assessments of PTSD, depression, dissociation, anxiety, and resilience. Linear models were completed to investigate racial/ethnic differences in posttraumatic dysfunction with subsequent follow-up models assessing potential effects of prior life stressors. RESULTS: Racial/ethnic groups did not differ in symptoms over time; however, Black participants showed reduced posttraumatic depression and anxiety symptoms overall compared to Hispanic participants and White participants. Racial/ethnic differences were not attenuated after accounting for differences in sociodemographic factors. However, racial/ethnic differences in depression and anxiety were no longer significant after accounting for greater prior trauma exposure and childhood emotional abuse in White participants. CONCLUSIONS: The present findings suggest prior differences in previous trauma exposure partially mediate the observed racial/ethnic differences in posttraumatic depression and anxiety symptoms following a recent trauma. Our findings further demonstrate that racial/ethnic groups show similar rates of symptom recovery over time. Future work utilizing longer time-scale data is needed to elucidate potential racial/ethnic differences in long-term symptom trajectories.

Childhood adversities and risk of posttraumatic stress disorder and major depression following a motor vehicle collision in adulthood.

AIMS: Childhood adversities (CAs) predict heightened risks of posttraumatic stress disorder (PTSD) and major depressive episode (MDE) among people exposed to adult traumatic events. Identifying which CAs put individuals at greatest risk for these adverse posttraumatic neuropsychiatric sequelae (APNS) is important for targeting prevention interventions. METHODS: Data came from n = 999 patients ages 18-75 presenting to 29 U.S. emergency departments after a motor vehicle collision (MVC) and followed for 3 months, the amount of time traditionally used to define chronic PTSD, in the Advancing Understanding of Recovery After Trauma (AURORA) study. Six CA types were self-reported at baseline: physical abuse, sexual abuse, emotional abuse, physical neglect, emotional neglect and bullying. Both dichotomous measures of ever experiencing each CA type and numeric measures of exposure frequency were included in the analysis. Risk ratios (RRs) of these CA measures as well as complex interactions among these measures were examined as predictors of APNS 3 months post-MVC. APNS was defined as meeting self-reported criteria for either PTSD based on the PTSD Checklist for DSM-5 and/or MDE based on the PROMIS Depression Short-Form 8b. We controlled for pre-MVC lifetime histories of PTSD and MDE. We also examined mediating effects through peritraumatic symptoms assessed in the emergency department and PTSD and MDE assessed in 2-week and 8-week follow-up surveys. Analyses were carried out with robust Poisson regression models. RESULTS: Most participants (90.9%) reported at least rarely having experienced some CA. Ever experiencing each CA other than emotional neglect was univariably associated with 3-month APNS (RRs = 1.31-1.60). Each CA frequency was also univariably associated with 3-month APNS (RRs = 1.65-2.45). In multivariable models, joint associations of CAs with 3-month APNS were additive, with frequency of emotional abuse (RR = 2.03; 95% CI = 1.43-2.87) and bullying (RR = 1.44; 95% CI = 0.99-2.10) being the strongest predictors. Control variable analyses found that these associations were largely explained by pre-MVC histories of PTSD and MDE. CONCLUSIONS: Although individuals who experience frequent emotional abuse and bullying in childhood have a heightened risk of experiencing APNS after an adult MVC, these associations are largely mediated by prior histories of PTSD and MDE.

Bedside multimarker testing for risk stratification in chest pain units: The chest pain evaluation by creatine kinase-MB, myoglobin, and troponin I (CHECKMATE) study.

BACKGROUND: Earlier, rapid evaluation in chest pain units may make patient care more efficient. A multimarker strategy (MMS) testing for several markers of myocardial necrosis with different time-to-positivity profiles also may offer clinical advantages. METHODS AND RESULTS: We prospectively compared bedside quantitative multimarker testing versus local laboratory results (LL) in 1005 patients in 6 chest pain units. Myoglobin, creatine kinase-MB, and troponin I were measured at 0, 3, 6, 9 to 12, and 16 to 24 hours after admission. Two MMS were defined: MMS-1 (all 3 markers) and MMS-2 (creatine kinase-MB and troponin I only). The primary assessment was to relate marker status with 30-day death or infarction. More patients were positive by 24 hours with MMS than with LL (MMS-1, 23.9%; MMS-2, 18.8%; LL, 8.8%; P=0.001, all comparisons), and they became positive sooner with MMS-1 (2.5 hours, P=0.023 versus LL) versus MMS-2 (2.8 hours, P=0.026 versus LL) or LL (3.4 hours). The relation between baseline MMS status and 30-day death or infarction was stronger (MMS-1: positive, 18.8% event rate versus negative, 3.0%, P=0.001; MMS-2: 21.9% versus 3.2%, P=0.001) than that for LL (13.6% versus 5.5%, P=0.038). MMS-1 discriminated 30-day death better (positive, 2.0% versus negative, 0.0%, P=0.007) than MMS-2 (positive, 1.8% versus negative, 0.2%; P=0.055) or LL (positive, 0.0% versus negative, 0.5%; P=1.000). CONCLUSIONS: Rapid multimarker analysis identifies positive patients earlier and provides better risk stratification for mortality than a local laboratory-based, single-marker approach.

Cocaine-associated chest pain in a chest pain center.

Chest pain is the most common cocaine-related complaint. The objective of this study was to describe an emergency department-based chest pain center for patients with cocaine-associated chest pain and to evaluate the safety of this protocol by assessing cardiac complications at 30 days.

Identification of patients at risk by graded exercise testing in an emergency department chest pain center.

The study applied a retrospective follow-up design to determine the prognostic effect of graded exercise testing (GXT) in patients with low- to moderate-risk chest pain evaluated in an emergency department 9-hour protocol chest pain center (CPC) from January 1, 1993 to August 1, 1996. The cohort of 1,209 patients were followed to the date of death or first adverse cardiac event up to 1 year after CPC admission. Cardiac events were defined as coronary artery bypass graft, percutaneous transluminal coronary angioplasty, cardiogenic shock, cardiac-related death, congestive heart failure admission, ventricular tachycardia/ventricular fibrillation arrest, and myocardial infarction. Patients with acute ST-segment elevation or depression of >1 mm, positive enzyme (creatine kinase myocardial band) testing, or unstable angina during their CPC evaluation were admitted without GXT testing. Statistical analysis included chi-square test for complication rates and Cox proportional-hazards modeling. Nine hundred fifty-eight of 1,209 patients underwent GXT testing. Patients with positive, inconclusive, and normal GXTs had complication rates of 36.8% (7 of 19), 3.4% (9 of 267), and 1.1% (5 of 456), respectively. After adjusting for age, sex, and race, the relative risk of complication was 38.9 (95% confidence interval 11.7 to 129.6) with a positive GXT, and 3.6 (95% confidence interval 1.2 to 10.7) with an inconclusive GXT compared with a normal GXT. The GXT is a good prognostic indicator of adverse cardiac events in low- to moderate-risk chest pain in patients evaluated in an emergency department CPC.

The role of cardiac markers in the emergency department.

The emergency department (ED) evaluation of patients with potential acute coronary syndromes (ACS) has traditionally included initial cardiac marker testing for suspected acute myocardial infarction (AMI). While ED management decisions for patients with ACS have largely been based on history, physical examination, and a presenting 12-lead electrocardiogram (ECG), there is ample evidence that markers impact treatment decisions and provide risk stratification. Newer, more sensitive markers of myocardial necrosis have blurred the distinction between patients with and without classically defined AMI, and have focused attention on the continuum of ACS from angina to transmural Q-wave MI. Newer antiplatelet agents, the glycoprotein IIb/IIIa receptor blockers, are likely to receive increased ED utilization. This use will be partially driven by ED cardiac marker determination. Bedside, point-of-care testing is reliable technology that may shorten time to diagnosis and treatment of ACS in the emergency setting. The ED-based chest pain center (CPC) has become a popular tool to evaluate patients at low- to moderate-risk for ACS and a non-diagnostic ECG. Such centers use serial cardiac marker testing as a mainstay for evaluation and risk stratification. Cost issues have driven many diagnostic patient evaluations from the inpatient setting to such ED observation units. As this becomes more common for low- to moderate-risk patients with chest pain, serial assessment of cardiac markers, and their interpretation by emergency physicians, will become essential.

A survey of adolescents' knowledge regarding toxicity of over-the-counter medications.

OBJECTIVE: With prior research suggesting that up to 17% of adolescents believe that acetaminophen (APAP) cannot cause death at any dose, this study surveyed adolescents regarding their knowledge of over-the-counter (OTC) medication toxicity. METHODS: A convenience sample of 13- to 18-year-olds presenting to the acute care clinic or ED at 2 teaching hospitals were given a survey requesting demographic data and information regarding common OTC medications. The respondents were asked to identify those OTC medications found at home, those they thought poisonous or lethal when taken in overdose, and those they thought contain alcohol. They also were asked to indicate whether they ever had made a suicidal overdose gesture. RESULTS: There were 203 of 210 (96% response rate) surveys completed. Recognition of the potential for overdose lethality with specific OTC medications was limited: aspirin (63%), APAP (57%), antihistamines (46%), iron (24%), camphor (22%), methyl salicylate (21%), and bismuth subsalicylate (19%). Additionally, adolescents commonly believed many OTC medications generally considered nonlethal would be fatal in an overdose: ibuprofen (51%), decongestants (45%), guaifenesin (29%), mouthwash (25%), kaolin-pectin (22%), antacids (21%), and vitamin C (12%). More than half of the respondents correctly identified agents that normally contain alcohol. Also, of the 5 respondents who previously made suicidal gestures, 4 indicated the ingested item could kill them, reflecting serious intent. CONCLUSION: Surveyed adolescents possess poor knowledge of the lethal potential of OTC medications; the fact that many adolescents believe several of these OTC medications are benign is concerning. Emergency physicians should adjust their assessments of individual overdose patients' suicidal intents accordingly.

An approach to emergency department photography.

In the emergency department, photography requires an expedient, portable, adaptable, and relatively simple camera system to take advantage of fleeting opportunities for recording visually educational material. These prerequisites are different from those for traditional medical photography, for which relatively plentiful time and advanced equipment are routinely available. Medical photography departments provide an invaluable service, but are rarely convenient for immediate or spontaneous emergency department photographs. Although no single system or technique is optimal in all these areas, the authors find certain components and approaches work well. They review photographic equipment, paying attention to speed, ease of use, and quality of output. They also review simple techniques such as film choice, lighting, close-up photography, standardization, copy work, and radiographs. Attention to these details can help the inexperienced photographer obtain a system and begin to enjoy the rewards of effective photography in the emergency department.

The dextromethorphan defense: dextromethorphan and the opioid screen.

OBJECTIVE: To determine whether a single oral dose of dextromethorphan produces a falsely positive qualitative urine opioid screen. METHODS: A prospective, randomized, triple-blind, placebo-controlled, crossover exposure study design was used. Twenty adult volunteers participated. All were without routine medications, not pregnant or lactating, without known sensitivity to dextromethorphan, and negative for urine toxicologic screening immediately prior to testing. These volunteers underwent three separate urine Enzyme-Multiplied Immunoassay Technique (EMIT) opioid screens. Each screen was performed six hours after the subject had ingested a single liquid medication, either dextromethorphan, codeine, or placebo. Each volunteer took all three medications randomly, at least 72 hours apart. Half of the volunteers took the standard adult dose of dextromethorphan (20 mg), while the other half ingested twice this amount (40 mg). The amounts of codeine (30 mg) and sucrose placebo (10 mL) remained constant. RESULTS: For these young adults (mean age +/- SD = 30.7 +/- 2.8 years), all urine EMIT assays six hours after ingestion of dextromethorphan, at both dosage levels, were negative for opioids and all other drugs. All assays after codeine and placebo ingestion were positive and negative for opioids, respectively. CONCLUSION: Although dextromethorphan is structurally similar to opioid drugs, the ingestion of a single normal (or even twice normal) dose of dextromethorphan is not likely to produce a falsely positive six-hour urine opioid EMIT screen.

Sensitivity of new-generation computed tomography in subarachnoid hemorrhage.

OBJECTIVE: To determine the sensitivity of the initial new-generation CT (NGCT) scan interpretation for detection of acute nontraumatic subarachnoid hemorrhage (SAH) and to decide whether lumbar puncture (LP) should follow a "normal" NGCT scan. METHODS: A retrospective chart review was performed of patients admitted between March 1988 and July 1994 with proven SAH. Exclusion criteria were age < 2 years, diagnosis other than acute SAH, history of head trauma within 24 hours before symptom onset, NGCT scan not done before diagnosis, and records not available. Patients were placed into two groups: symptom duration < 24 hours (group 1) and > 24 hours (group 2) prior to CT scan. The resolution of each NGCT scanner was recorded. An NGCT scanner was defined as a third-generation scanner or more recent. RESULTS: Of 349 SAH patients, 181 met inclusion criteria. The sensitivity of NGCT scans for SAH was 93.1% for the group 1 patients (n = 144) and 83.8% for the group 2 patients (n = 37). The overall sensitivity was 91.2%. All the patients who had SAH not detected by NGCT scans were diagnosed by LP. There was no significant relationship between NGCT scanner resolution and sensitivity for SAH. CONCLUSION: Initial interpretation of NGCT scans to detect SAH does not approach 100% sensitivity. A "normal" NGCT scan does not reliably exclude the need for LP in patients who have symptoms suggestive of SAH.

The impact of an endotracheal side port on the absorption of lidocaine.

OBJECTIVE: To compare lidocaine levels after administration through an i.v. line, a standard endotracheal (ET) tube, and an ET tube side port (ETSP) designed for medication administration. METHODS: A double-blind, prospective, triple crossover canine study was performed. Seventeen anesthetized mongrel dogs were given standard doses of 2% lidocaine via i.v. (1.5 mg/kg), endotracheally through the main lumen (3 mg/kg diluted in 10 mL normal saline), and endotracheally through the modified side port (3 mg/ kg diluted in 10 mL normal saline). Arterial blood gases (ABGs) and plasma lidocaine levels were measured at time 0, 30 sec, 1 min, 5 min, 10 min, 20 min, 30 min, and 60 min. Mean lidocaine levels across time, comparing the 3 methods of administration, were analyzed with repeated-measures analysis of variance. The main outcome was the comparison of mean ET and ETSP lidocaine levels at each time point using paired t-tests. The attainment and duration of lidocaine levels considered therapeutic in cardiac arrest (1.4 micrograms/mL) were described. ABGs were measured at each point to describe trends in oxygenation. RESULTS: Mean lidocaine levels, comparing the 3 methods of administration, were significantly different at all time points except time 0. The ETSP levels were significantly lower than the ET main-lumen levels at 30 sec, 1 min, 5 min, and 10 min. i.v.-administered lidocaine attained quick therapeutic levels and revealed faster elimination. Lidocaine administered through the ET main lumen reached therapeutic levels more slowly, and maintained such levels longer. Lidocaine administered through the ETSP never reached therapeutic levels. Mean PO2S remained > 340 torr throughout each method of administration. CONCLUSION: This nonarrest canine model suggests that lidocaine levels achieved through an ETSP are lower than levels obtained with the same drug dose via an ET main lumen. Therapeutic lidocaine levels are obtainable by i.v. or ET main-lumen routes, but not via this ETSP.

The effect of hyperbaric oxygen therapy on a burn wound model in human volunteers.

A previous nonblinded study has suggested beneficial effects from hyperbaric oxygen treatment of superficial partial-thickness radiation burns in human volunteers. This protocol was designed to either confirm or challenge these previous findings in a randomized, blinded format. Twelve healthy, nonsmoking volunteers (7 males, 5 females) participated. All were screened for contraindications to hyperbaric oxygen therapy (acute sinusitis, otitis media, pneumonia, pregnancy, active cancer, pneumothorax) and given a single test hyperbaric exposure. A standardized wound model was employed for the painless creation of a volar forearm lesion on volunteers by applying a suction device to form a blister, excising its epidermal roof, and irradiating the exposed dermis with ultraviolet light. Subjects were randomized into either a hyperbaric oxygen group (100% oxygen at 2.4 ATA, n = 6) or the sea-level air-breathing equivalent control group (8.75% oxygen at 2.4 ATA, n = 6). Both groups then underwent standard hyperbaric therapy. The subjects, the hyperbaric oxygen chamber operators, and the monitoring clinicians were all blinded to the oxygen concentration administered. Each subject received two dives per day over a 3-day period. The wounds were studied noninvasively prior to treatment and once per day over 6 days for size, hyperemia, and exudation, with epithelialization as the endpoint. The averages for each measurement of the hyperbaric oxygen group versus the control group were computed by means of a one-tail t test; p was considered significant at less than 0.05. Daily wound size, hyperemia, and exudation measurements were significantly different on day 2. The hyperbaric oxygen group showed a 42 percent reduction in wound hyperemia, a 35 percent reduction in the size of the lesion, and a 22 percent reduction in wound exudation (p values of 0.05, 0.03, and 0.04, respectively). No significant difference was noted for epithelialization. Observed differences in wound size, hyperemia, and exudation were attributable to hyperbaric oxygen therapy. This study further supports earlier conclusions that hyperbaric oxygen therapy is beneficial in a superficial dermal wound.

Traumatic bilateral carotid dissection.

Traumatic dissection of the carotid artery is an infrequent but serious complication of blunt cranial-cervical injury. The typical patient presents with deficits attributable to cerebral ischemia in the distribution of the affected vascular supply. Key considerations in the clinical picture are a delay in symptom presentation, normal initial computed tomography scans, and potential for concomitant cerebral or visceral injury. Because the initial clinical and diagnostic picture may be normal, it is crucial for emergency physicians to aggressively search for this injury in the presence of blunt cranial trauma. We present an unusual case of bilateral high extracranial carotid dissection secondary to blunt trauma. The pathophysiology of carotid artery trauma, treatment options, and key acute care issues are discussed.

Heart emergency room: effective for both geriatric and younger patients.

OBJECTIVES: To compare the 30-day cardiac event rate between patients aged at least 60 years (geriatric group) with those younger than 60 (younger group), who were enrolled in an Emergency department-based chest pain centre management protocol. METHODOLOGY: This was a retrospective, cohort study done at the Centre for Emergency Care at the University of Cincinnati, from 1 Oct 1991 to 31 March 1999 (from Oct 1991 to Dec 1998: 9-hour protocol in use; from Jan 1999 to March 1999: 6-hour protocol in use). Patients, at least 25 years, with the chief complaint of non-traumatic chest pain were eligible for management in the unit. Exclusion criteria included acute ST-elevation or depression > 1 mm in 2 contiguous leads, haemodynamic instability or clinical syndrome consistent with unstable angina. Outcomes studied were disposition and cardiac events at 30-days (defined as acute myocardial infarction, congestive heart failure, ventricular fibrillation / tachycardia arrest, coronary artery bypass surgery or percutaneous transluminal coronary angioplasty). The protocol was the standard of care and enrolled patients underwent continuous ECG and ST-segment trend monitoring, serial CK-MB draws at 0, 3, 6 and 9 hours, followed by either a graded exercise stress test or a sestamibi myocardial perfusion scan (from Oct 1998). With the 6-hour protocol the 9-hour draws were omitted and the GXTdone 3 hours earlier. RESULTS: A total of 2491 patients were enrolled; 304 (12.2%) in the geriatric age-group. The mean age was 66.8+/-5.9 and 41.3+/-8.6 years respectively. There were 133 (43.8%) female patients in the geriatric group and 1170 (53.5%) in the younger group. There were no statistically significant differences between the groups in terms of prevalence of risk factors, but there was significant (p < 0.001) and ECG changes from the baseline (p = 0.0015). The geriatric patients were also not different from the younger ones in terms of GXT positive for ischaemia (10, 5.3% vs 42, 2.7%; p = 0.124), admission rates (61, 20.1% vs 321, 14.7%; p = 0.312), coronary care unit admissions (8, 2.6% vs 63, 2.9%; p = 0.418 and 30-day complication rate (10, 3.6% vs 46, 2.4%; p = 0.303). CONCLUSION: The ED-based chest pain unit represents an effective way for the risk-stratification and management of both geriatric and young patients with low-to-moderate risk of acute coronary events.

Comparison of a 6-hour and 9-hour protocol for evaluation of moderate-to-low risk chest pain patients in an emergency department diagnostic unit.

OBJECTIVE: To compare the 30-day outcomes of patients enrolled in a 6-hour and 9-hour emergency department (ED)-based chest pain centre (CPC) protocol. METHODS: All patients with the chief complaint of chest pain, who were older than 25 years, or with cocaine usage within 96 hours of initial presentation, were eligible for enrolment. Exclusion criteria included acute ST-segment elevation or depression >1 mm in 2 contiguous leads, history of coronary artery disease (CAD), haemodynamic instability or clinical syndromes consistent with unstable angina. Outcomes included ED disposition and cardiac events at 30 days (defined as acute myocardial infarction (AMI), percutaneous trans-luminal coronary angiography (PTCA), coronary artery bypass graft surgery (CABG),ventricular tachycardia or fibrillation (VT/VF) arrest, congestive heart failure (CHF) admission or cardiac-related death). The 9-hour protocol consisted of ST-segment monitoring,serial CK-MB draws at 0, 3,6 and 9 hours as well as a graded exercise test (GXT) prior to ED disposition. The 6-hour protocol eliminated the 9-hour serum marker determination, included cardiac Troponin-I (cTn-I) and allowed a GXT, 3 hours earlier. Follow-up was obtained by medical record review, phone contact, letter and also review of national and state death registries. RESULTS: The 9-hour protocol (October 1991-December 1997) included 2,133 patients and the 6-hour protocol (January 1998- August 1998) had 184 patients enrolled. The 6-hour protocol was not different from the 9-hour one in terms of percentage admissions (9-hour: 310, 14.5%; 6-hour: 33, 17.9%; p=0.213), Coronary Care Unit admission (9-hour: 59, 2.8%; 6-hour: 5, 2.7%; p=0.303) or 30-day cardiac events (9-hour: 38, 1.9%; 6-hour: 2, 1.3%; p=0.605). CONCLUSION: The 6-hour CPC strategy is an effective and safe evaluation method for patients at low to moderate risk for acute coronary syndromes.

Mass casualties from acute inhalation of chloramine gas.

Mass exposure to chloramine gas has not been reported. We report two groups of 36 patients (72 total) suffering from acute inhalation of chloramine gas. Chloramine gas is produced from mixing common household cleaning agents containing sodium hypochlorite (bleach) and ammonia. The first mass casualty event occurred when 36 male soldiers were exposed during a "cleaning party" in their barracks. Ten days later, 36 female soldiers were exposed in a similar manner and presented to our emergency department. In each event, commonly available cleaning agents--liquid bleach and ammonia--were mixed together, liberating toxic chloramine gas. Nebulized sodium bicarbonate solution has been suggested for treatment of chlorine gas inhalation, but no report of nebulized sodium bicarbonate for treatment of chloramine gas inhalation injury exists. In our series, 22 patients exposed to chloramine gas were treated with a nebulized solution of 3.75% sodium bicarbonate. This treatment made no significant statistical or clinical difference in outcome. We present the largest case series of patients presenting to an emergency department for treatment of acute inhalation of chloramine gas.

Bupropion overdose and seizure.

There is little experience with overdose of the relatively new antidepressant bupropion. The case of an 18-year-old healthy adult female patient after an intentional ingestion of 9 g of bupropion is presented. Her hospital course was significant for grand mal seizures, sinus tachycardia without conduction abnormality, and complete neurological recovery. The first pure bupropion overdose in the emergency medicine literature is presented, and the literature pertinent to emergent management of this new antidepressant is reviewed.

Chest pain centers: diagnosis of acute coronary syndromes.

Chest pain centers in the emergency department have generally been accepted as a safe, cost-effective, and rapid approach to the evaluation, triage, and management of patients with potential acute coronary syndromes. These centers were initially designed to enhance patient care by decreasing time to treatment for acute myocardial infarction (AMI) and rapidly identifying patients with unstable angina. They also included community outreach and educational objectives designed to reduce time from the onset of chest pain to ED presentation. In the past decade, health care financial constraints have created additional impetus to the development of chest pain centers. Cost reduction efforts have occurred to reduce hospitalizations, lengths of stay, and unnecessary treatments and procedures. Practitioners and administrators try to balance these goals with the imperative to provide high-quality patient care. Protocol-driven approaches have been developed for specific disease processes in emergency settings. The chest pain center concept is such an approach for patients with chest pain. Chest pain is the second most common ED presenting complaint and is a symptom related to the leading cause of death in the United States, coronary artery disease (CAD). One third of ED patients with chest pain will eventually have a diagnosis of acute coronary syndrome. Many patients with acute coronary syndromes have atypical presentations that are not diagnosed in the ED with the traditional diagnostic evaluation of a history, physical examination, and 12-lead ECG. If they are not admitted to the hospital for further evaluation, the diagnosis may be missed. The 2% to 5% of AMI patients who are inadvertently released home often have poor outcomes and result in a leading cause of malpractice suits in emergency medicine. More than one half of ED patients with chest pain have clinical findings after their initial evaluation consistent with acute coronary syndromes and are admitted to the hospital. Approximately one half of these patients, after evaluation in the hospital, are found not to have acute coronary syndromes. The cost for these negative inpatient cardiac evaluations has been estimated to be $6 billion in the United States each year. Today, chest pain centers serve as an integral component of many EDs. Their success and safety is the result of a focused, protocol-driven approach directed at the acute coronary syndrome continuum from unstable angina to transmural Q-wave myocardial infarction. New therapies for acute coronary syndromes make ED triage and risk stratification increasingly important. Although different chest pain center protocols have proved effective, all address the diagnosis and rapid treatment of acute myocardial necrosis, rest ischemia, and exercise-induced ischemia. Identifying patients with coronary artery disease in one of these stages in the spectrum of myocardial ischemia is the foundation for a successful chest pain center in the ED.