Chest Pain Protocol Research Articles

Diagnosing acute cardiac ischemia in the emergency department: A systematic review of the accuracy and clinical effect of current technologies

Study Objective: Acute cardiac ischemia (ACI) encompasses the diagnoses of unstable angina pectoris and acute myocardial infarction (AMI). Accurate diagnosis and triage of patients with ACI in the emergency department should increase survival for these patients and reduce unnecessary hospital admissions. Methods: We conducted a systematic review of the English-language literature published between 1966 and December 1998 on the accuracy and clinical effect of diagnostic technologies for ACI. We evaluated prospective and retrospective studies of adult patients who presented to the ED with symptoms suggesting ACI. Outcomes were diagnostic performance (test sensitivity and specificity) and measures of clinical effect. Meta-analyses were performed when appropriate. A decision and cost-effectiveness analysis was conducted that investigated various diagnostic strategies used in the diagnosis of ACI in the ED. Results: We screened 6,667 abstracts, reviewed 407 full articles, and included 106 articles articles in the main analysis. Single measurements of biomarkers at presentation to the ED have low sensitivity for AMI, although they have high specificity. Serial measurements greatly increase the sensitivity for AMI while maintaining their excellent specificity. Diagnostic technologies to evaluate ACI in selected populations, such as electrocardiography, sestamibi perfusion imaging, and stress ECG, may have very good to excellent sensitivity; however, they have not been sufficiently studied. The Goldman Chest Pain Protocol has good sensitivity (about 90%) for AMI but has not been shown to result in any differences in hospitalization rate, length of stay, or estimated costs in the single clinical effect study performed. Its applicability to patients with unstable angina pectoris has not been evaluated. The use of an Acute Cardiac Ischemia-Time-Insensitive Predictive Instrument led to the appropriate triage of 97% of patients with ACI presenting to the ED and reduced unnecessary hospitalizations. Conclusion: Many of the current technologies remain underevaluated, especially regarding their clinical effect. The extent to which combinations of tests may provide better accuracy than any single test needs further study. [Lau J, Ioannidis JPA, Balk EM, Milch C, Terrin N, Chew PW, Salem D. Diagnosing acute cardiac ischemia in the emergency department: a systematic review of the accuracy and clinical effect of current technologies. Ann Emerg Med. May 2001;37:453-460.]

Can Practice Guidelines Be Transported Effectively to Different Settings? Results from a Multicenter Interventional Study

Although clinical guidelines have become increasingly popular as a means to reduce variation in care, increase efficiency, and improve patient outcomes, little is known about their effectiveness when they are transported outside their original setting, or about the factors that influence their successful translation into clinical practice. This study assessed whether a clinical guideline for low-risk chest pain patients, implemented with a standardized protocol, could be effectively transported to five hospital settings. In a prospective, interventional trial, a standardized protocol for low-risk chest pain was implemented at each site. A total of 553 consecutively hospitalized low-risk patients with chest pain were enrolled during a 3-month baseline period followed by a standardized 6-month intervention period. During the intervention period, each patient's physician was contacted about eligibility for discharge within the specified 2-day guideline period. Guideline adherence (discharged within 48 hours) and postdischarge patient outcomes were measured. Local guideline champions were interviewed about their implementation experience. Guideline adherence during the intervention period ranged from 61% to 100%, with only two sites achieving significant increases of > or = 10% from the baseline values. Guideline implementation did not affect clinical outcomes or patient satisfaction. Implementation factors such as preexisting hospital environment, implementation team staffing, and the rapid identification and resolution of barriers may influence the successful translation of guidelines into practice. Even with a standardized implementation protocol, consistent results across institutions were not obtained when a clinical guideline for chest pain was implemented beyond its original setting. These findings demonstrate the importance of understanding the local factors that influence guideline implementation.

Critical pathways : a review. Committee on Acute Cardiac Care, Council on Clinical Cardiology, American Heart Association.

Critical pathways, also known as critical paths, clinical pathways, or care paths, are management plans that display goals for patients and provide the sequence and timing of actions necessary to achieve these goals with optimal efficiency.1 As competition in the healthcare industry has increased, managers have embraced critical pathways as a method to reduce variation in care, decrease resource utilization, and potentially improve healthcare quality. Cardiovascular medicine in particular is an area in which critical pathways have been embraced. This is due in part to the high volume and high cost associated with cardiovascular diseases and procedures. In addition, the relatively mature guideline process has also contributed to the growth in use of critical pathways in cardiology. Although anchored in clinical guidelines, the critical pathway is a distinct tool that details processes of care and highlights inefficiencies regardless of whether there is evidence to warrant changes in those processes. Clinical guidelines, on the other hand, are consensus statements that are systematically developed to assist practitioners in making patient management decisions related to specific clinical circumstances.2 Although clinical guidelines can and should be used in pathway development, the majority of processes included in a pathway have not been rigorously tested and are generally not addressed in guidelines. Another term that should also be distinguished from critical pathways is clinical protocols. Protocols are treatment recommendations that are often based on guidelines. Like the critical pathway, the goal of the clinical protocol may be to decrease treatment variation. However, protocols are most often focused on guideline compliance rather than the identification of rate-limiting steps in the patient care process. In further contrast to critical pathways, protocols may or may not include a continuous monitoring and data-evaluation component. Critical pathway techniques were first developed for use in industry as a tool to …

An accelerated emergency department diagnostic protocol for chest pain reduced hospitalization and costs

An accelerated emergency department diagnostic protocol for chest pain reduced hospitalization and costs

An Evaluation of a Chest Pain Diagnostic Protocol to Exclude Acute Cardiac Ischemia in the Emergency Department

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). 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. 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. 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.

Evaluation of a Prehospital Chest Pain Protocol

Study objectives: To evaluate the diagnostic accuracy and outcomes for patients treated by use of a prehospital chest pain protocol (CPP). Design: Consecutive case series for 1 year (1993) of prehospital nontrauma advanced life support (ALS) cases including hospital outcomes. Setting: Nonurban two-tiered emergency medical services system. Participants: Patients treated under the prehospital CPP or with hospital diagnoses of ischemic heart disease (IHD; ICD-9 between 410 and 414). Patients with cardiac arrest or dysrhythmias were excluded. Interventions: Patients were given, by standing orders, ECG monitoring, IV access, and sublingual nitroglycerin. Further therapy was guided by on-line medical direction. Results: Of 3,122 ALS nontrauma patients, 620 (20%) were treated with the CPP. All patients underwent ECG monitoring, IV access was started in 83%, and 61% received nitroglycerin. Only 55% of patients completed the entire CPP; patients who failed to complete the CPP had the same prevalence of IHD as those who completed it. When compared with hospital diagnosis of IHD, the CPP had a sensitivity of 69% (95% confidence interval [CI], 64% to 74%), a specificity of 87% (95% CI, 86% to 88%), and a positive predictive value of 42%. The positive likelihood ratio of CPP for IHD was 5.31, and the negative likelihood ratio was .36. The hospital mortality rate for all patients was 2.2%; for those with IHD, it was 1.6%. Conclusion: This prehospital ALS CPP had good diagnostic accuracy, but only half of patients completed it, and the hospital mortality rate was low. These data challenge the efficacy of the CPP. [Wuerz RC, Meador SA: Evaluation of a prehospital chest pain protocol. Ann Emerg Med November 1995;26:595-597.]

Prehospital recognition of AMI using independent nurse/paramedic 12-lead ECG evaluation: Impact on in-hospital times to thrombolysis in a rural community hospital

Because the benefits from thrombolytic therapy in acute myocardial infarction (AMI) are time dependent, multiple strategies have been devised to speed therapy. This study sought to determine whether hospital-based nurse and paramedic advanced life support (ALS) providers could be trained to independently evaluate (sight read) a prehospital 12-lead electrocardiogram (ECG) for the presence of AMI as part of a protocol designed to speed in-hospital administration of thrombolytic agents. Providers were required to determine on the basis of a protocol (1) whether or not AMI was present, and (2) whether or not thrombolytic therapy was indicated. Providers then radioed their impression to the emergency department (ED) and initiated a protocol to prepare identified candidates for thrombolysis. The final decision to initiate thrombolytic therapy was made by the ED physician after patient arrival at the hospital. One hundred fifty-five patients with chest pain were studied. Twenty-one (13.5%) were ultimately proven in-hospital to have AMI. Providers were able to recognize AMI in 17 of 21. Four of 21 did not meet ECG criteria for AMI on the field ECG, but were categorized as having a high index of suspicion for AMI by providers. There were no false-positive diagnoses. Fourteen patients (9%) received thrombolytic therapy. In-hospital times to administration of thrombolytic therapy decreased to an average of 22 ± 13.8 minutes in the studied group compared with a historical control group average of 51 ± 50 minutes. It is concluded that hospital-based paramedics and nurses can successfully be taught to evaluate (ie, sight read) a prehospital ECG for the presence of AMI with accuracy. A prehospital chest pain protocol using a field ECG can speed in-hospital administration of thrombolytic therapy to the extent that field administration of thrombolytic agents may not significantly improve times to administration of therapy when transport times are similar to those of this study.

A comparison of paramedic versus basic emergency medical care of patients at high and low risk during acute myocardial infarction

This prospective study compares the outcome of patients with acute myocardial infarction managed by mobile intensive care (paramedic phase) with that of similar patients managed by basic emergency medical care (control phase) in the same community before the introduction of paramedics. All paramedic-transported patients were managed according to a standard chest pain protocol with use of prophylactic lidocaine and, as needed, treatment for sinus bradycardia, hypotension and life-threatening ventricular arrhythmia. There were no specific interventions for supraventricular tachyarrhythmia or hypertension. All patients were treated under similar in-hospital protocols. Percent mortality in patients with hypotension, the highest risk subgroup in the control phase, was significantly lowered with paramedic-level care (69 versus 10%, p = 0.01). Patients with hypertension, a relatively low risk subgroup during the control phase (16% mortality), were also at lower risk during the paramedic phase (10% mortality). In fact, there was no mortality in either study phase for patients with an initial systolic blood pressure greater than 180 mm Hg. During the combined study phases, patients with normotension and tachycardia demonstrated a tendency toward higher percent mortality (33%) than either patients with normotension without tachycardia (10%) or those with hypertension and tachycardia (6%). Although the overall percent mortality was reduced by 24% (from 21 to 16%), this decrease was largely due to the improvement of patients with hypotension. Investigation into the feasibility of prehospital interventions for the high risk patient with acute myocardial infarction normotension and tachycardia appears warranted.

Computers in Medicine

IT IS time for an office practitioner to comment on the rash of recent literature on computers in medicine. 1-4 Indeed, it is appropriate to ask if many office practitioners read these articles with any practical interest. INTERNIST-1, the chest pain protocol, INFERNET, ONCOCIN, and so on are unlikely to be used by most of us. As their respective authors correctly point out, they are at present mainly research tools, and teach us a lot about how medical reasoning works—principally from the computers' shortcomings. Thus, it is comforting to learn that INTERNIST-1 also has difficulty reasoning temporally, anatomically, and pathophysiologically at the same time. Nonetheless, it is clear that computers are here to stay, and not just at busy emergency rooms or the university hospitals. Because of the incredible price breakthroughs, it is likely that every medical practice will employ or share one within the next few years. The computer