Identification of Chest Pain Patients Appropriate for an Emergency Department Observation Unit - 03/09/11

Doi : 10.1016/S0733-8627(05)70167-X

Keith Wilkinson, MD, FACEP ^a, Harry Severance, MD ^b
^a Emergency Medicine Residency Program, William Beaumont Hospital, Royal Oak; the Department of Emergency Medicine, Wayne State University, Detroit, Michigan (KW)
^b Division of Emergency Medicine, Department of Emergency Medicine, Duke University Medical Center, Durham, North Carolina (HS)

Résumé

Chest pain is the second commonest chief complaint presenting to US emergency departments (ED), accounting for 5.2% of visits in 1996 equal to 5 million people.^{25Gibler W.B., Lewis L.M., Erb R.E., et al. Early detection of acute myocardial infarction in patients presenting with chest pain and nondiagnostic ECGs. Serial CK-MB sampling in the emergency department Ann Emerg Med 1990 ; 9 : 1359-1366 [cross-ref]

Cliquez ici pour aller à la section Références, 75National Center for Health Statistics: US Dept. of Health and Human Services, 1994.

Cliquez ici pour aller à la section Références, 98Stussman B.J. National Hospital Ambulatory Medical Care Survey: 1995 Emergency Department Summary Advance data from Vital and Health Statistics of the Center for Disease Control and Prevention/National Center for Health Statistics. (DHHS publication no. [PHS] 97-1250) 1997 ; 285 : 1-18

Cliquez ici pour aller à la section Références, 106The World Almanac Book of Facts. New York, St. Martin Press 1999. Vital Statistics, Top 20 Reasons Given by Patients for an Emergency Room Visit. 1996, 884.

Cliquez ici pour aller à la section Références} From 10% to 31% have acute coronary ischemia (ACI) as the cause of their visit.^{26Gibler W.B., Young G.P., Hedges J.R., et al. Acute myocardial infarction in chest pain patients with nondiagnostic ECGs: Serial CK-MB sampling in the emergency department Ann Emerg Med 1992 ; 21 : 504-512

Cliquez ici pour aller à la section Références, 29Goldman L., Cook E.F., Brand D.A., et al. A computer protocol to predict myocardial infarction in emergency department patients with chest pain N Engl J Med 1988 ; 318 : 797-803 [cross-ref]

Cliquez ici pour aller à la section Références, 68Lee T.H., Weisberg M., Cook E.F., et al. Evaluation of creatine kinase and creatine kinase-MB for diagnosing myocardial infarction: Clinical impact in the emergency room Arch Intern Med 1987 ; 147 : 115-121 [cross-ref]

Cliquez ici pour aller à la section Références} Acute coronary ischemia (ACI) encompasses the syndromes of acute myocardial infarction (AMI) and unstable angina (UA). The challenge is to identify the patient with acute coronary ischemia out of all of those presenting with chest pain and to recognize atypical presentations (e.g., dyspnea, weakness, syncope, palpitations, and confusion). The rate of discharge of AMI patients ranges from 1.9% to 3.8% with up to 25% suffering death or complications.^{66Lee T.H., Rouan G.W., Weisberg M.C., et al. Clinical characteristics and natural history of patients with acute myocardial infarction sent home from the emergency room Am J Cardiol 1987 ; 60 : 219-224 [cross-ref]

Cliquez ici pour aller à la section Références, 74McCarthy B.D., Beshansky J.R., D'Agostino R.B., et al. Missed diagnoses of acute myocardial infarction in the emergency department: Results from a multicenter study Ann Emerg Med 1993 ; 22 : 579-582 [cross-ref]

Cliquez ici pour aller à la section Références} Patients inadvertently released with an AMI have a mortality rate of nearly twice those correctly diagnosed and admitted. Failure to diagnose and treat AMI continues to account for the largest amount of dollars paid for claims against emergency physicians.^{86Rusnak R.A., Stair T.O., Hansen K., et al. Litigation against the emergency physician: Common features in cases of missed myocardial infarction Ann Emerg Med 1989 ; 18 : 1029-1034 [cross-ref]

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Once the diagnosis of ACI is suspected, the second goal is appropriate triage. This is based on immediate need for intervention, risk of death or serious complications, cost-effectiveness, and resource utilization. The cost of care of patients unnecessarily admitted to the CCU has been estimated at nearly $3 billion annually whereas the total estimated cost of liberal admissions to rule out AMI in low-risk patients has been estimated at up to $13 billion annually.^{21Fineberg H.V., Scadden D., Goldman L. Care of patients with a low probability of acute myocardial infarction: Cost-effectiveness of alternatives to coronary care unit admission N Engl J Med 1984 ; 310 : 1301-1307 [cross-ref]

Cliquez ici pour aller à la section Références, 84Roberts R., Kleiman N.S. Earlier diagnosis and treatment of acute myocardial infarction necessitates the need for a “new diagnostic mind-set.” Circulation 1994 ; 89 : 872-881 [cross-ref]

Cliquez ici pour aller à la section Références, 104Weingarten S.R., Ermann B., Riedinger M.S., et al. Selecting the best triage rule for patients hospitalized with chest pain Am J Med 1989 ; 87 : 494-500 [cross-ref]

Cliquez ici pour aller à la section Références} The setting (e.g., CCU, intermediate care unit, monitored hospital ward, ED Chest Pain Observation Unit [CPOU], or the outpatient setting) and pace of work up for ACI are based on the risk of short-term, life-threatening cardiac events (e.g., myocardial infarction, malignant arrhythmia, recurrent ischemia, need for revascularization, pump failure, and death). The focus on this article is on the clinical factors and technologies currently available in the ED to stratify the probability of ACI for these patients. It discusses the impact of specific features of the history, physical examination, and ECG on decision making as well as existing algorithms and prediction models. Last, it will address the roles of echocardiography and perfusion imaging currently being defined.