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Prediction of the Need for Intensive Care in Patients Who Come to Emergency Departments with Acute Chest Pain

BACKGROUND Patients who come to the emergency department with chest pain are a heterogeneous group. Some have ischemic heart disease that may lead to serious complications, whereas others have minor disorders. We performed a study to identify clinical factors that predict which patients will have complications requiring intensive care. METHODS We first studied 10,682 patients with acute chest pain at seven hospitals between 1984 and 1986 (derivation set) to identify potential clinical predictors of the development of major complications. We then validated these predictors in a separate set of 4676 patients at one hospital between 1990 and 1994 (validation set). RESULTS In the derivation set of patients, we identified the following set of clinical features, which, if present in the emergency department, were associated with an increased risk of complications: ST-segment elevation or Q waves on the electrocardiogram thought to indicate acute myocardial infarction, other electrocardiographic changes indicating myocardial ischemia, low systolic blood pressure, pulmonary rales above the bases, or an exacerbation of known ischemic heart disease. On the basis of these criteria, the patients in the validation set were stratified into four groups, with the risk of major complications in the first 12 hours ranging from 0.15 to 8 percent. After 12 hours, the probability of a major complication could be updated on the basis of whether the patient had already had a complication of major severity, a complication of intermediate severity, or a myocardial infarction (independent relative risks, 18.9, 7.7 and 4.0, respectively, as compared with patients without prior complications or myocardial infarction). CONCLUSIONS The risk of major complications in patients with acute chest pain can be estimated on the basis of the clinical presentation and new clinical observations made during the hospital course. These estimates of risk help in making rational decisions about the appropriate level of medical care for patients with acute chest pain.

Effect of Race on the Presentation and Management of Patients with Acute Chest Pain

National data indicate that the rate of decline in mortality from coronary heart disease has been more rapid in whites than in African-Americans [1-4]. Among the many possible explanations for this discrepancy is reduced access to beneficial care, including sophisticated cardiologic procedures. Wenneker and Epstein [5] showed that African-Americans were significantly less likely than whites to have cardiac procedures in Massachusetts hospitals in 1985. Maynard and colleagues [6] found that African-Americans in the Seattle-based Myocardial Infarction Triage and Intervention (MITI) Registry had significantly fewer angioplasty and coronary artery bypass grafting procedures than did whites. Goldberg and colleagues [7] analyzed national Medicare data from 1986 and showed that among persons insured by Medicare, African-Americans had a significantly lower rate of coronary artery bypass grafting procedures when compared with whites. Unfortunately, these studies lacked sufficiently detailed clinical information to determine whether these differences were a function of differing clinical characteristics or even whether the rates were higher than appropriate in whites, lower than appropriate in African-Americans, or both. For example, African-Americans have a significantly lower rate of hospital discharge with acute myocardial infarction as the primary diagnosis [8]. Although ischemic heart disease is the leading cause of death in African-Americans as well as in whites, the effect of race on clinical course and outcomes (that is, on the natural history of ischemic heart disease) in patients with chest pain has not been well studied [9]. Thus, further information is needed to understand racial differences in the rates of cardiac procedures. To address this need, we merged detailed clinical and resource utilization data on 3031 patients from two hospitals to measure the effect of race on the clinical presentation, the natural history of disease, and the resource utilization of patients coming to the emergency department because of acute chest pain. Our detailed patient-specific information permitted us to adjust for clinical characteristics and complications to understand the basis for any differences in overall procedure rates. Methods Study Design The Multicenter Chest Pain Study, a cooperative investigation of the clinical characteristics and outcomes of emergency-department patients with acute chest pain, was conducted between December 1983 and October 1986 [9-18]. All patients 30 years or older who came to one of the participating emergency departments with a chief complaint of anterior, precordial, or left lateral chest pain that could not be explained by obvious local trauma or abnormalities on a chest radiograph were eligible. The emergency-department physician, who was usually an intern or a resident, recorded clinical data at the time of presentation, including the patients age; sex; findings from the history, physical examination, and electrocardiogram; and results of cardiac enzyme assessments. The emergency-department physician or a research nurse recorded these data on a standardized data form that was part of the permanent medical record at a time when he or she had no knowledge of, and could not be biased by, the patients subsequent course. Data on race were collected prospectively in 94% of patients at the University of Cincinnati Hospital and retrospectively, by chart review, in 96% of patients at the Brigham and Womens Hospital. Patients from these two hospitals composed our study group. The term African-American is used to describe blacks residing in the continental United States who are of African descent. Each patient visit was considered an individual event. Only the first three visits for each patient during the study period were included in the analysis. Patients who experienced cardiac arrest in the emergency department were excluded from the study. During the study period, 4173 potentially eligible patient visits occurred at the two hospitals (Figure 1). A trained study nurse reviewed the charts of all admitted patients, recording data on cardiac enzyme levels, official discharge diagnoses, and dates and times of complications and procedures. Figure 1. Derivation of the study population of 3031 patients from the 4173 patients who came to the emergency department with acute chest pain. Consent was obtained from 1991 (79%) of the 2522 discharged patients. The other 531 nonconsenting, discharged patients did not differ significantly from the 1991 consenting patients in terms of gender or age. Consenting, nonadmitted patients were retained in the study only if the investigators, who were blinded to all of the patients emergency-department data, thought that the follow-up information was sufficient to place the patient into a diagnostic category, as defined below. Sixty-two percent of the consenting, nonadmitted patients included in the final study sample had a follow-up assessment of cardiac enzyme levels, and 66% had either assessment of cardiac enzyme levels or a follow-up visit. Those nonadmitted patients who did not return for follow-up evaluation were contacted by telephone to assess their clinical status. In such cases, patients considered to be at a higher risk for myocardial infarction because of a suspicious pain description, electrocardiographic abnormalities, or continuing symptoms were encouraged by telephone to return for an evaluation; if they were still unwilling to return, further follow-up was obtained by telephone and contact with the patients personal physician. Patients who returned for a follow-up visit or enzyme assessment were similar to patients who received telephone follow-up with regard to sex and age, but African-Americans were more likely than whites to have enzyme assessments, electrocardiograms, or both (71% compared with 61%, P < 0.0001). Race was identified in 1593 (97%) of the 1640 admitted patients and 1676 (94%) of the 1787 consenting, discharged patients with adequate follow-up. The 226 Hispanic and 12 Asian patients were excluded because of their small number. Therefore, the final study sample included 3031 patients: 1508 admitted patients (35% African-American, 49% male) and 1523 consenting, nonadmitted patients (55% African-American, 39% male). Data on zip-code and insurance status were available from one of the two hospitals. Household income was estimated by matching zip codes with 1980 census data on median household income in that geographic location. Diagnoses A final diagnosis of acute myocardial infarction was made in both admitted and nonadmitted patients on the basis of one of the following criteria: 1) characteristic evolution of serum enzyme levels, as defined by the detection of creatine kinase MB isoenzyme levels in more than trace amounts by the qualitative electrophoretic assay or as at least 5% of an elevated total creatine kinase level and showing a typical rise and fall by the quantitative assay; by a lactic dehydrogenase isoenzyme 1 level that was greater than the isoenzyme 2 level in the absence of hemolysis or renal infarction; or, if isoenzymes were not assayed, by serial total creatine kinase levels demonstrating a typical rise and fall, with a peak value exceeding twice the usual upper limit of normal; 2) an electrocardiogram showing development of pathologic Q waves [at least 0.04 seconds in duration] and at least a 25% decrease in the amplitude of the following R wave compared with that of the emergency-department electrocardiogram; and 3) sudden unexplained death within 72 hours of presentation. In the Chest Pain Study, the purpose of which was to define optimal management strategies for patients with acute chest pain, discharged patients with sudden death within 72 hours of admission were classified as having had an acute myocardial infarction unless contradicting data were found, because admission to an intensive or coronary care unit would have been the preferred triage strategy had this outcome been anticipated. Admitted patients who had sudden cardiac arrests and died before cardiac enzyme assessments could be done were similarly classified unless other explanations for the arrest emerged. In all of these patients, the presenting characteristics, electrocardiograms, and clinical courses were most consistent with the diagnosis of acute myocardial infarction. All patients who underwent coronary reperfusion with thrombolytic therapy showed electrocardiographic or enzymatic evidence of acute myocardial infarction before undergoing the procedure. Patients who showed creatine kinase and creatine kinase MB isoenzyme elevations after but not before an invasive procedure (for example, coronary arteriography, coronary angioplasty, or coronary artery bypass grafting) were considered not to have had infarctions, because such procedures were done at the discretion of the physicians who were caring for the patients, and acute myocardial necrosis might not have occurred if the patients had been managed conservatively. The final diagnosis of acute ischemic heart disease was made if the patient was found to have either acute myocardial infarction or unstable angina. Unstable angina was diagnosed if 1) the patients original emergency-department chest pain syndrome was either new or worse (in frequency, severity, or duration) than his or her chronic anginal syndrome; and 2) the diagnosis of angina was made by the senior clinician associated with the case. Table 1. Characteristics of the Study Sample Stratified by Race* Major complications were defined as follows: ventricular fibrillation requiring lidocaine or defibrillation, Mobitz II second-degree atrioventricular block requiring temporary or permanent pacing, new complete heart block, cardiogenic shock, or cardiac arrest. Cardiac catheterization data were collected retrospectively by chart review. Statistical Analysis Racial distribution differed by hospital, with African-Americans accoun

Predicting bacteremia in hospitalized patients: a prospectively validated model.

OBJECTIVE To develop and validate a model for the prediction of bacteremia in hospitalized patients, and to identify subgroups of patients with a very low likelihood of bacteremia in whom a positive blood culture has a low positive predictive value. DESIGN Prospective cohort study with clinical data on 1516 episodes collected from a random sample of all patients who had blood cultures done at one institution. SETTING Urban, tertiary care hospital. PATIENTS Derivation set: 1007 blood culture episodes sampled from all blood cultures done on patients at Brigham and Womens Hospital between October 1988 and February 1989. Validation set: 509 episodes, May 1989 to June 1989. The unit of evaluation was the episode, defined as a 48-hour period beginning after a blood culture was drawn. MEASUREMENTS AND MAIN RESULTS True- and false-positive rates of blood cultures in the derivation set as assessed by independent reviewers were 7% (74 of 1007) and 8% (81 of 1007), respectively. Independent multivariate predictors of true bacteremia were temperature of 38.3 degrees C or higher, presence of a rapidly (less than 1 month) or ultimately (less than 5 years) fatal disease; shaking chills; intravenous drug abuse; acute abdomen on examination; and major comorbidity. In the low-risk group, defined by absence of these predictors, the misclassification rate of the model in the derivation set was 1% (4 of 303), and a positive blood culture had a positive predictive value of only 14% for true bacteremia. The model also identified a high-risk subset in which 16% (41 of 264) of episodes represented true bacteremia. The model was prospectively validated in 509 additional episodes, and the misclassification rate in the low-risk group was 2% (3 of 155). INTERVENTIONS None. CONCLUSION These findings provide a means of stratifying hospitalized patients according to their risk for bacteremia. If prospectively validated in other settings, this model may be helpful when deciding whether or not to do blood cultures or start antibiotic therapy and, when evaluating a positive blood culture, to determine whether or not it is a true-positive.

Sensitivity of routine clinical criteria for diagnosing myocardial infarction within 24 hours of hospitalization.

Myocardial infarction was diagnosed in 431 (30%) of 1460 patients with acute chest pain who had serial enzyme testing after admission to intensive or intermediate care units at three teaching and three community hospitals. The diagnosis was made within 12 hours of admission in 331 (77%) patients and within 24 hours in 415 (96%). Of the 16 patients with myocardial infarction who did not have enzyme abnormalities within 24 hours, 9 (56%) had recurrent ischemic pain during this 24-hour period. Of 451 patients who had neither enzyme abnormalities nor recurrent ischemic pain in the first 24 hours, only 7 (2%) ultimately met diagnostic criteria for myocardial infarction. These findings were prospectively validated in an independent testing set of 275 patients with myocardial infarction, 271 (99%) of whom either met diagnostic criteria for myocardial infarction or had recurrent ischemic pain within 24 hours of admission. These data suggest that 24 hours is nearly always a sufficient period to exclude myocardial infarction in patients without recurrent chest pain.

Importance of Findings on the Initial Evaluation for Cancer in Patients with Symptomatic Idiopathic Deep Venous Thrombosis

The association between advanced cancer and deep venous thrombosis has been well documented, and preexisting visceral cancer is a risk factor for deep venous thrombosis [1, 2]. Some studies [3-7] have suggested that deep venous thrombosis might be a marker for subsequent cancer, but others [8-10] have failed to show such an association. The clinical evaluation for diagnosing underlying cancer in patients with idiopathic deep venous thrombosis remains a challenging problem for physicians [11]. In previous studies of the possible association between deep venous thrombosis and cancer [3, 5, 6, 8], comparison groups comprised patients with secondary deep venous thrombosis (that is, patients with known risk factors [other than cancer] for deep venous thrombosis), patients in whom idiopathic or secondary deep venous thrombosis was suspected but not confirmed [4, 10], or the general population [7, 10]. These studies yielded conflicting results. It would be more appropriate to compare the incidence of cancer in patients who have idiopathic deep venous thrombosis with the incidence of cancer in patients in whom idiopathic deep venous thrombosis had been suspected but was ruled out. Our study was designed to 1) determine the appropriate initial clinical evaluation for cancer in patients with symptomatic idiopathic deep venous thrombosis and 2) estimate the likelihood that cancer will subsequently be diagnosed in patients who had negative results on a clinical evaluation for cancer when deep venous thrombosis occurred. Methods Patient Sample All adults who had venous ultrasonography at Brigham and Womens Hospital (Boston, Massachusetts) between January 1990 and May 1993 because deep venous thrombosis in a lower extremity was suspected were eligible. The study cohort was selected from the daily log of the vascular diagnostic laboratory. Patients were excluded if they presented with a risk factor for deep venous thrombosis [12, 13], such as preexisting cancer; had recently had surgery (within 3 months); had had prolonged immobilization ( 10 days); had recently had trauma to a lower limb (within 3 months); had a documented hypercoagulable state (either deficiency of antithrombin III, protein C, or protein S or the presence of a lupus anticoagulant); were pregnant; had recently given birth (within 2 weeks); or were using oral contraceptives. We also excluded patients who had had a procedure (such as computed tomography of the abdomen) to identify potential underlying cancer before venous ultrasonography, even though the diagnosis of cancer was not known at the time when venous ultrasonography was done. Patients who had had venous ultrasonography as part of the work-up for suspected pulmonary embolism were also excluded because our primary goal was to assess the work-up for cancer in patients with symptomatic idiopathic deep venous thrombosis (such as those with leg pain or swelling), not in patients with chest pain or shortness of breath. If a patient had venous ultrasonography more than once between January 1990 and May 1993, only the first ultrasonogram was considered. The exclusion criteria were chosen before any data were collected. We did not exclude patients with a history of deep venous thrombosis because a recent study [6] showed an increased risk for cancer in patients with recurrent deep venous thrombosis. Of the 5797 venous ultrasonographic examinations, 3445 (59%) were excluded because they had been done in patients who had one or more risk factors (other than cancer) for deep venous thrombosis. Four hundred sixty (8%) of the patients in whom venous ultrasonography was done as part of the work-up for suspected pulmonary embolism were also excluded. Eight hundred thirty patients (14%) were excluded because they had ultrasonography as a follow-up procedure. Fourteen patients (0.2%) were excluded either because a work-up for cancer had been done before venous ultrasonography or because they refused to receive a mailed questionnaire about their medical situation. Finally, 62 patients (1%) were excluded because follow-up information was missing (Figure 1). None of these 62 patients received a diagnosis of deep venous thrombosis. The final cohort comprised 986 patients. The study was approved by the Human Research Committee of Brigham and Womens Hospital. Figure 1. Branching tree of the number of patients included at every stage of the study. Venous Ultrasonography and Definition of Deep Venous Thrombosis In all patients, duplex, color-assisted venous ultrasonography was done in each leg; 5.0 and 7.0 MHz transducers were used as described elsewhere [14]. Diagnosis of deep venous thrombosis was based on the lack of apposition on the venous walls during compression maneuvers. The presence or absence of venous flow augmentation was assessed by color-flow imaging and Doppler waveform analysis (done while the calf muscles were squeezed) to identify the deep venous thrombosis as occlusive or nonocclusive. Findings were confirmed by two observers. Deep venous thrombosis was classified as calf (tibial, peroneal, gastrocnemius, or soleal veins) or proximal (popliteal or femoral veins) venous thrombosis. Venous ultrasonography was used as the gold standard. Data Collection A standardized form was used to collect the following data from the charts of all study patients: date of birth, sex, place of residence, date of procedure, and current or previous use of tobacco. For all patients hospitalized with deep venous thrombosis, a second standardized form was used to collect clinical data from the charts about the initial clinical evaluation. This data included the results of medical history, physical examination, and laboratory tests. This 86-item form was based on the current recommendations for early cancer detection [15, 16] and included 1) findings in the medical history suggestive of underlying cancer, such as weight loss, fatigue, unusual pain, recent modification of bowel or bladder habits, unusual bleeding, or recent modification of cough or hoarseness; 2) findings on the physical examination suggestive of underlying cancer, such as abnormalities on abdominal or breast palpation (abnormal mass), oral cavity examination (ulcerative lesion), skin examination (atypical pigmentation), digital rectal examination (prostatic nodule or irregularities on the rectal walls), or lymphadenopathy or chest auscultation [rales or dullness]; 3) laboratory findings suggestive of underlying cancer, such as positive results on a test for fecal occult blood, abnormal values on the complete blood count and SMA 20, abnormal erythrocyte sedimentation rate, or abnormal results on urinalysis; 4) abnormalities on chest radiography suggestive of underlying cancer, such as lung nodules, pleural effusion, or mediastinal adenopathy; and 5) abnormal results of other procedures, such as computed tomography, ultrasonography, endoscopy, and biopsy. We also recorded the results of laboratory tests that were done after discharge but were related to the work-up done during hospitalization. Knowledge of previous laboratory test results can affect the observation or the recording of clinical findings [17], but we minimized this potential ascertainment bias by collecting data from the medical record only for the first clinical examination. This chart review form also recorded data on alcohol consumption and history of deep venous thrombosis. The person who reviewed the records was blinded to the occurrence of cancer during follow-up. Follow-up and Definition of Cancer The follow-up information for study patients in whom cancer was not diagnosed at the time of referral for ultrasonography was obtained through hospital chart review (38%), computerized record extraction (in patients who were members of a health maintenance organization in the Boston, Massachusetts, area) (54%), mailed questionnaires (6%), telephone interviews (1%), or the death registry of the Massachusetts Registry of Vital Records and Statistics (1%). Follow-up information included occurrence of cancer by site and date (including cancer found at autopsy), date of death or date on which the patient was last known to be alive, cause of death, and occurrence of deep venous thrombosis. Only the first diagnosis of cancer for each patient was considered. All cases of cancer were confirmed by histologic (95%) or cytologic (5%) examination, with the exception of one case of pancreatic cancer for which a clinical diagnosis was accepted. The patient who had this case had a pancreatic mass and liver metastases detected by computed tomography and died 3 weeks after discharge. Cases of nonmelanoma skin cancer were not included. One hundred twenty-two of the 142 patients with deep venous thrombosis (the deep venous thrombosis group) and all of the 844 patients who did not have deep venous thrombosis (the comparison group) who had not received a diagnosis of cancer when deep venous thrombosis was suspected were followed for a median of 34 months (minimum, 3 months [unless the patient died within the first 3 months]; maximum, 60 months). This yielded 304 person-years of follow-up for the deep venous thrombosis group and 2548 person-years of follow-up for the comparison group (Figure 1). Ninety-five percent of the patients in the deep venous thrombosis group and 96% of those in the comparison group were followed for at least 1 year, until death, or until the occurrence of cancer; 2% of the deep venous thrombosis group and 4% of the comparison group were followed for 3 to less than 6 months; and 3% of the deep venous thrombosis group and 2% of the comparison group were followed for 6 to less than 12 months. No follow-up information was obtained for 4 of the 126 patients (3%) in the deep venous thrombosis group. Three of these 4 patients had no findings suggestive of cancer on the initial clinical evaluation when deep venous thrombosis was diagnosed, and the fourth (a 75-year-old man) had only mild anemia, moved to

The effect of gender on the probability of myocardial infarction among emergency department patients with acute chest pain: a report from the Multicenter Chest Pain Study Group.

Objective: To identify differences in the incidences of myocardial infarction in women and men with chest pain.Design: Prospective multicenter cohort study.Setting: Emergency rooms of three university and four community bospitals.Patients: 7,734 emergency room patients with acute chest pain.Measurements and main results: Myocardial infarction was diagnosed in 10% of the 3,896 women, compared with 19% of the 3,838 men, yielding an age-adjusted relative risk of myocardial infarction for women of 0.54 (95% confidence interval 0.48, 0.60). Physicians were equally adept at admitting women and men with myocardial infarctions, but men without myocardial infarction or unstable angina were significantly more likely to be admitted than were women without these diagnoses. Most clinical and electrocardiographic features indicating a risk of myocardial infarction were present in both women and men, but several high-risk features were less commonly present in women. After adjusting for the other factors that correlate with each patient’s probability of having acute myocardial infarction, the relative risk of myocardial infarction was the same in women as men when the emergency department electrocardiogram showed the classic changes associated with acute myocardial infarction, but the risk was 40% lower in women when such electrocardiographic changes were not present.Conclusions: Clinical features that predict myocardial infarction in men predict myocardial infarction in women to a similar extent. However, female gender is associated with about a 40% lower rate of myocardial infarction except when classic electrocardiographic evidence is present on the emergency department electrocardiogram.

Physician response to a prediction rule for the triage of emergency department patients with chest pain

Objective: To determine the response of physicians to a noncoercive prediction rule for the triage of emergency department patients with chest pain.Design: Prospective time-series intervention study.Setting: A university hospital emergency department.Participants/patients: 68 physicians, all of whom were responsible for the triage of at least one of 252 patients presenting to the emergency department with a chief complaint of acute chest pain.Intervention: A previously validated algorithmic prediction rule that was attached to the back of patient data forms in the emergency department.Measurements: Patients’ clinical data were recorded by the examining physician in the emergency department or by a research nurse blinded to patient outcome. The physicians recorded their own estimates of the risk of acute myocardial infarction and their reactions to the prediction rule in a self-administered questionnaire completed at the time of triage.Main results and conclusions: The physicians reported that they looked at the prediction rule during the triage of 115 (46%) of the 252 patients. The likelihood of using the prediction rule decreased significantly with increasing level of physician training. The most common reasons given for disregarding the prediction rule were confidence in unaided decision making and lack of time. The physicians reported that of the 115 cases for which the prediction rule was used, only one triage decision (1% ) was changed by it. Future research should explore how prediction rules can be designed and implemented to surmount the barriers highlighted by these data.

Diagnostic implications for myocardial ischemia of the circadian variation of the onset of chest pain

To determine whether the occurrence of chest pain is randomly distributed during the day and to study whether the time of onset is useful in discriminating among causes of chest pain, patients older than 30 years who presented to 7 emergency departments with a chief complaint of chest pain unexplained by trauma or chest x-ray abnormalities were studied. A total of 7,759 patients presented during the study period; of these, 3,990 presented within 6 hours of the onset of pain and were included in the primary analysis. Chest pain caused by acute myocardial infarction, unstable angina pectoris and stable angina pectoris was more likely to begin during the period from 6 AM to noon than would be expected if the onset were uniformly distributed during the day (relative risks 1.15, 1.29 and 1.32, respectively), but chest pain that was caused by nonischemic cardiac causes and by noncardiac causes was also more likely to begin during the same time period (relative risks 1.28 and 1.17). Although chest pain from coronary arterial causes had a distinct circadian variation, the time of onset of pain was not a helpful criterion for determining the cause of chest pain.

Impact of initial triage decisions on nursing intensity for patients with acute chest pain.

The results of a prospective evaluation of the patient-specific correlates of nursing intensity for 183 consecutive emergency room patients admitted for evaluation of acute chest pain, including 33 (18%) with acute myocardial infarction (AMI), are reported. These correlates were measured with a previously-validated, commercially-available patient classification tool (Medicus). In multiple linear regression analysis that adjusted for the effects of 31 clinical variables from the initial presentation and subsequent course, initial triage to the coronary care unit had a significant independent correlation with initial Medicus score (P < 0.0001) and mean Medicus score from the first three days of hospitalization (P < 0.0001). In a subset of 74 uncomplicated non-AMI patients, coronary care unit admissions were more likely to have vital signs taken every 2 hours, to receive oxygen therapy and assistance with feeding, and to be transferred to another unit within three days. Findings suggest that, after adjusting for severity of illness, initial triage of patients with acute chest pain to the coronary care unit is associated with increased nursing utilization because of 1) the routine application of standard coronary care unit protocols that were developed for high-risk patients, and 2) the nursing efforts required by early transfer of patients out of the coronary care unit.