Jon W. Schrock

Identifying Patients for Early Discharge: Performance of Decision Rules Among Patients with Acute Chest Pain

BACKGROUND The HEART score and North American Chest Pain Rule (NACPR) are decision rules designed to identify acute chest pain patients for early discharge without stress testing or cardiac imaging. This study compares the clinical utility of these decision rules combined with serial troponin determinations. METHODS AND RESULTS A secondary analysis was conducted of 1005 participants in the Myeloperoxidase In the Diagnosis of Acute coronary syndromes Study (MIDAS). MIDAS is a prospective observational cohort of Emergency Department (ED) patients enrolled from 18 US sites with symptoms suggestive of acute coronary syndrome (ACS). The ability to identify participants for early discharge and the sensitivity for ACS at 30 days were compared among an unstructured assessment, NACPR, and HEART score, each combined with troponin measures at 0 and 3h. ACS, defined as cardiac death, acute myocardial infarction, or unstable angina, occurred in 22% of the cohort. The unstructured assessment identified 13.5% (95% CI 11.5-16%) of participants for early discharge with 98% (95% CI 95-99%) sensitivity for ACS. The NACPR identified 4.4% (95% CI 3-6%) for early discharge with 100% (95% CI 98-100%) sensitivity for ACS. The HEART score identified 20% (95% CI 18-23%) for early discharge with 99% (95% CI 97-100%) sensitivity for ACS. The HEART score had a net reclassification improvement of 10% (95% CI 8-12%) versus unstructured assessment and 19% (95% CI 17-21%) versus NACPR. CONCLUSIONS The HEART score with 0 and 3 hour serial troponin measures identifies a substantial number of patients for early discharge while maintaining high sensitivity for ACS.

Predicting observation unit treatment failures in patients with skin and soft tissue infections

BackgroundSkin and soft tissue infections are a common admission diagnosis to emergency department (ED) observation units (OU). Little is known about which patients fail OU treatment.AimsThis study evaluates clinical factors of skin or soft tissue infections associated with further inpatient treatment after OU treatment failure.MethodsA structured retrospective cohort study of consecutive adults treated for abscess or cellulitis in our OU from April 2005 to February 2006 was performed. Records were identified using ICD-9 codes and were abstracted by two trained abstractors using a structured data collection form. Significant variables on univariate analysis P < 0.1 were entered into a multivariate logistic regression.ResultsA total of 183 patient charts were reviewed. Four patients with a non-infectious diagnosis were excluded, leaving 179 patients. The median age was 41 (interquartile range: 20–74). Following observation treatment, 38% of patients required admission. The following variables were evaluated for association with failure to discharge home: intravenous drug use, gender, a positive community-acquired methicillin-resistant Staphylococcus aureus culture, age, presence of medical insurance, drainage of an abscess in the ED, diabetes and a white blood cell count (WBC) greater than 15,000. Following multivariate analysis only female gender odds ratio (OR) 2.33 [95% confidence interval (CI): 1.06–5.15] and WBC greater than 15,000 OR 4.06 (95% CI: 1.53–10.74) were significantly associated with failure to discharge.ConclusionsAmong OU patients treated for skin and soft tissue infections, women were twice as likely to require hospitalization and patients with a WBC > 15,000 on presentation to the ED, regardless of gender, were 4 times more likely to require hospitalization.

Elevated blood urea nitrogen/creatinine ratio is associated with poor outcome in patients with ischemic stroke

OBJECTIVE Dehydration may impair cerebral oxygen delivery and worsen clinical outcome in patients with acute ischemic stroke (AIS). We evaluated if elevated blood urea nitrogen to creatinine ratio (BUN/Cr) as a marker of dehydration was associated with poor clinical outcome in emergency department (ED) patients presenting with AIS. METHODS We conducted a prospective cohort study using a stroke registry enrolling all ED patients with AIS from 10/2007 through 6/2009. Poor clinical outcome was defined as death, placement in a nursing home for purposes other than rehabilitation, or hospice within 30 days of ED presentation. A BUN/Cr ratio of ≥15 was considered elevated. (IQR). Logistic regression was performed adjusted for age >64 years, NIHSS >8, diabetes, prior CVA, and coma at presentation reporting odds ratios with 95% confidence intervals. RESULTS 324 patients had a final diagnosis of AIS. 163 (50%) were female, 19 (6%) died, 44 (14%) received t-PA, and 89 (27%) had a poor clinical outcome. The median NIHSS, BUN and Cr were 4 (IQR 1-9), 14 mg/dL (IQR 11-21), and 1.02 mg/dL (IQR 0.87-1.27) respectively. The median BUN/Cr was 13.9 (IQR 10.6-18.5). The variables associated with a poor clinical outcome were: high NIHSS OR 6.5 (3.6-11.8), age >64 years OR 2.7 (1.5-5.0), and BUN/Cr ratio of ≥15 OR 2.2 (1.2-4.0). CONCLUSION An elevated BUN/Cr ratio in patients with AIS is associated with poor outcome at 30 days. Further study is needed to see if acutely addressing hydration status in ED patients with AIS can alter outcome.

CLUE: a randomized comparative effectiveness trial of IV nicardipine versus labetalol use in the emergency department

IntroductionOur purpose was to compare the safety and efficacy of food and drug administration (FDA) recommended dosing of IV nicardipine versus IV labetalol for the management of acute hypertension.MethodsMulticenter randomized clinical trial. Eligible patients had 2 systolic blood pressure (SBP) measures ≥180 mmHg and no contraindications to nicardipine or labetalol. Before randomization, the physician specified a target SBP ± 20 mmHg (the target range: TR). The primary endpoint was the percent of subjects meeting TR during the initial 30 minutes of treatment.ResultsOf 226 randomized patients, 110 received nicardipine and 116 labetalol. End organ damage preceded treatment in 143 (63.3%); 71 nicardipine and 72 labetalol patients. Median initial SBP was 212.5 (IQR 197, 230) and 212 mmHg (IQR 200,225) for nicardipine and labetalol patients (P = 0.68), respectively. Within 30 minutes, nicardipine patients more often reached TR than labetalol (91.7 vs. 82.5%, P = 0.039). Of 6 BP measures (taken every 5 minutes) during the study period, nicardipine patients had higher rates of five and six instances within TR than labetalol (47.3% vs. 32.8%, P = 0.026). Rescue medication need did not differ between nicardipine and labetalol (15.5 vs. 22.4%, P = 0.183). Labetalol patients had slower heart rates at all time points (P < 0.01). Multivariable modeling showed nicardipine patients were more likely in TR than labetalol patients at 30 minutes (OR 2.73, P = 0.028; C stat for model = 0.72)ConclusionsPatients treated with nicardipine are more likely to reach the physician-specified SBP target range within 30 minutes than those treated with labetalol.Trial registrationClinicalTrials.gov: NCT00765648

Variables associated with discordance between emergency physician and neurologist diagnoses of transient ischemic attacks in the emergency department.

STUDY OBJECTIVE Transient ischemic attack is a common clinical diagnosis in emergency department (ED) patients with acute neurologic complaints. Accurate diagnosis of transient ischemic attack is essential to help guide evaluation and avoid treatment delays. We seek to determine the prevalence of discordant diagnosis for patients receiving an ED diagnosis of transient ischemic attack compared with neurologist final diagnosis. Secondary goals are to evaluate the influence of atypical transient ischemic attack symptoms, the ABCD2 score, and emergency physician experience on discordant diagnoses. METHODS We performed a retrospective cohort study evaluating all ED patients receiving a diagnosis of transient ischemic attack during a 4-year period. The emergency physician diagnosis was compared with that of the neurologist. The neurologists final diagnosis was considered the criterion standard diagnosis. Subject demographic and clinical information was collected with a structured instrument. The following atypical symptoms present at the ED evaluation were evaluated with logistic regression: headache, tingling, involuntary movement, seeing flashing lights or wavy lines, dizziness, confusion, incontinence, and ABCD2 score of 4 or greater. Bivariate analysis was used to evaluate the influence of emergency physician experience (≤6 years versus >6 years) on discordant diagnosis. Odds ratios (ORs) and proportions are reported with 95% confidence intervals (CIs), interquartile range was used where appropriate. RESULTS We evaluated 436 subjects, of whom 7 were excluded, allowing 429 subjects for evaluation. Of these individuals, 156 (36%; 95% CI 32% to 41%) received a discordant diagnosis. The median emergency physician time in clinical practice was 6 years (interquartile range 2 to 12 years). Features associated with a discordant transient ischemic attack diagnosis included headache (OR 2.52; 95% CI 1.59 to 3.99), involuntary movement (OR 3.19; 95% CI 1.35 to 7.54), and dizziness (OR 1.92; 95% CI 1.22 to 3.02). Incontinence, confusion, and seeing wavy lines or flashing lights were not significantly associated with a discordant diagnosis. Patients with tingling and a high ABCD2 score had an increased odds of concordant transient ischemic attack diagnosis (OR 0.54, 95% CI 0.32 to 0.92; OR 0.53, 95% CI 0.35 to 0.82, respectively). CONCLUSION Discordant diagnoses between emergency physicians and neurologists were observed in 36% of patients. The presence of headache, involuntary movement, and dizziness predicted discordant diagnoses, whereas the presence of tingling and an increased ABCD2 score predicted concordant transient ischemic attack diagnosis.

A Novel Emergency Department Dysphagia Screen for Patients Presenting With Acute Stroke

OBJECTIVES Dysphagia is a common complication for emergency department (ED) patients presenting with acute stroke (AS). Recent stroke recommendations have suggested that EDs screen patients with AS for dysphagia prior to administering anything by mouth. This study sought to develop and test a novel ED dysphagia screen to be used in this population. METHODS A multidisciplinary approach was used to create a novel dysphagia screen performed by ED nurses during the initial evaluation of patients with suspected AS. The screen consists of five questions of which any single affirmative answer signified possible dysphagia. A prospective cohort study was conducted to evaluate the performance of this screen in detecting dysphagia after AS. Patients were followed for 30 days, and true dysphagia was determined if the patient had an abnormal modified barium swallow study (MBS), had placement of a feeding tube, or was placed on a dysphagia diet after assessment by a speech pathologist. The authors performed a substudy to determine agreement using a blinded kappa (κ) assessment with a convenience sample of 40 patients. RESULTS Over a 21-month period, 283 patients met eligibility for analysis. The rate of cerebral infarction in this cohort was 245 (87%). The rates for true dysphagia, pneumonia, and death were 91 (32%), 26 (9%), and 18 (6%), respectively. The dysphagia screen had a sensitivity of 95% (95% confidence [CI] = 88% to 98%) and a negative likelihood ratio of 0.1 (95% CI = 0.04 to 0.2). The inter-rater agreement assessed by kappa was substantial (0.69, 95% CI = 0.55 to 0.83). CONCLUSIONS These data suggest that this dysphagia screen may be a valuable tool for detecting dysphagia in ED patients presenting with AS. The simple screen can be performed by nursing personnel and appears to perform well with good agreement. Given the overall rate of dysphagia in one-third of AS patients, the use of an ED dysphagia screen appears warranted.

Myeloperoxidase in the diagnosis of acute coronary syndromes: The importance of spectrum

BACKGROUND Myeloperoxidase (MPO) is proposed for risk stratification in patients with suspected acute coronary syndromes (ACSs). We determined if MPO has diagnostic value in patients being evaluated for ACS. METHOD MIDAS was an 18-center prospective study enrolling suspected ACS emergency department patients who presented <8 hours after symptom onset and in whom serial cardiac markers and objective cardiac perfusion testing were planned. Blinded MPO (Biosite, Inc, San Diego, CA) and troponin I (Triage Cardio 3; Biosite, Inc) were drawn at arrival, and Troponin I (TnI) was measured at 90, 180, and 360 minutes. Final diagnoses were adjudicated by the local investigator blinded to study assay. RESULTS Of 1,018 patients, 54% were male, 26% black, with a mean age of 58 ± 13 years. Diagnoses were ACS in 288 (23%) and noncardiac chest pain (NCCP) in 788 (77%). Of patients with ACS, 94 (9.2%) had a myocardial infarction (MI) at presentation (69 non-ST-elevation MI, 25 ST-elevation MI), and 136 had unstable angina. Using a cutpoint of 210 ng/mL to provide 90% specificity, MPO had a sensitivity of 0.18; negative predictive value, 0.69; positive predictive value, 0.47; negative likelihood ratio, 0.91; and a positive likelihood ratio of 1.83 to differentiate ACS and NCCP. Because of the large overlap of quartiles, MPO was not clinically useful to predict serial TnI changes. The C statistics ± 95% CI for MPO differentiating ACS from NCCP and for AMI versus NCCP were 0.629 ± 0.04 and 0.666 ± 0.06, respectively. CONCLUSIONS Myeloperoxidase has insufficient accuracy for decision making in patients with suspected ACS.

Absolute and relative changes (delta) in troponin I for early diagnosis of myocardial infarction: Results of a prospective multicenter trial

OBJECTIVES We investigated absolute and relative cardiac troponin I (TnI) delta changes, optimal sampling protocols, and decision thresholds for early diagnosis of myocardial infarction (MI). Serial cardiac biomarker values demonstrating a rise and/or fall define MI diagnosis; however the magnitude of change, timing, and diagnostic accuracy of absolute versus relative (percentage) deltas remains unsettled. METHODS We prospectively measured TnI (AccuTnI+3™, Beckman Coulter) at serial time intervals in 1929 subjects with chest pain or equivalent symptoms of acute coronary syndrome at 14 medical centers. Diagnosis was adjudicated by an independent central committee. RESULTS Elevated TnI above a threshold of 0.03ng/mL demonstrated significant diagnostic efficacy (AUC 0.96). For patients with TnI<0.03ng/mL and symptom onset≥8h, 99.1% (NPV) were diagnosed with conditions other than MI. Absolute delta performed significantly better than relative delta at 1-3h (AUC 0.84 vs 0.69), 3-6h (0.85 vs 0.73), and 6-9h (0.91 vs 0.79). Current recommendations propose ≥20% delta within 3-6h; however, results were optimized using an absolute delta of 0.01 or 0.02ng/mL. Sensitivity results for absolute delta at 1-3h and 3-6h (75.8%, 78.3%) were superior to relative delta (48.0%, 61.3%). NPV (rule out) was 99.6% when baseline TnI<0.03ng/mL and absolute delta TnI<0.01ng/mL. CONCLUSIONS Absolute delta performed significantly better than relative delta at all time intervals. Baseline TnI and absolute delta may be used in conjunction to estimate probability of MI. Consensus recommendations are supported for sampling on admission and 3h later, repeated at 6h in patients when clinical suspicion remains high.

Diagnostic performance of cardiac Troponin I for early rule-in and rule-out of acute myocardial infarction: Results of a prospective multicenter trial☆

OBJECTIVES To compare emergency department TnI serial sampling intervals, determine optimal diagnostic thresholds, and report representative diagnostic performance characteristics for early rule-in and rule-out of MI. METHODS We prospectively measured TnI (AccuTnI+3™, Beckman Coulter) at serial time intervals in 1929 subjects with chest pain or equivalent ischemic symptoms suggestive of acute coronary syndromes at 14 medical centers. Diagnosis was adjudicated by an independent central committee. RESULTS TnI ≥0.03ng/mL provided 96.0% sensitivity and 89.4% specificity at 1-3h after admission, and 94.9% sensitivity and 86.7% specificity at 3-6h. NPV (rule-out, non-MI) was 99.5% at 1-3h, and 99.0% at 3-6h when TnI is <0.03ng/mL. NPV was 99.1% when TnI is <0.03ng/mL and time of symptom onset is ≥8h. Approximately 50-58% (PPV) of patients with TnI ≥0.03ng/mL were diagnosed with MI, depending upon time from onset or admission; PPVs emphasize the importance of serial samples and delta TnI (rising or falling pattern) when low cutoffs are used. Nevertheless, even a single elevated TnI value increased the risk of MI. As TnI values rose, the probability of MI increased. Values ≥0.20ng/mL were associated with nearly 90% probability of MI. CONCLUSIONS We report a large multicenter prospective adjudicated trial assessing troponin for early rule-in and rule-out using the Universal Definition of MI and conducted in primary care hospital-associated emergency departments. Our study demonstrates high diagnostic accuracy at early observation times, and reinforces consensus recommendations for sampling on admission and 3h later, repeated at 6h when clinical suspicion remains high.

Can the ABCD2 Risk Score Predict Positive Diagnostic Testing for Emergency Department Patients Admitted for Transient Ischemic Attack

Background and Purpose— We sought to determine if the ABCD2 score, typically used for risk stratification, could predict having a positive diagnostic test in patients evaluated acutely for transient ischemic attack. Methods— We performed a retrospective cohort study for patients admitted from our emergency department with a new diagnosis of transient ischemic attack confirmed by a neurologist. ABCD2 scores were calculated and patients with a score of ≥4 were placed in the high-risk cohort. Tests evaluated included electrocardiogram, CT, MRI, MR angiography, carotid ultrasonography, and echocardiography. Specific test findings considered to signify positive diagnostic tests were created a priori. Results— We identified 256 patients with transient ischemic attack for inclusion; 167 (61%) were female, the median age was 60 years (interquartile range, 50 to 72), and 162 (63%) patients had an ABCD2 score of ≥4. Rates of completion of diagnostic testing were electrocardiogram, 270 (100%); CT, 224 (88%); MRI, 89 (35%); MR angiography, 68 (27%); carotid ultrasonography, 125 (49%); and echocardiography, 135 (53%). Univariate analysis found a significant association only with elevated ABCD2 score and carotid duplex testing (P<0.05). Conclusion— An elevated ABCD2 score may help predict patients with severe carotid occlusive disease but does not predict positive outcome in other commonly ordered tests for patients being evaluated for transient ischemic attack. An elevated ABCD2 score cannot be recommended as a tool to guide diagnostic testing in patients presenting acutely with transient ischemic attack.