Frederick K. Korley

Use of advanced radiology during visits to US emergency departments for injury-related conditions, 1998-2007.

CONTEXT Excessive use of medical imaging increases health care costs and exposure to ionizing radiation (a potential carcinogen) without yielding significant benefits to all patients. OBJECTIVE To determine whether there has been a change in the prevalence of emergency department visits for injury-related conditions for which computed tomography (CT) or magnetic resonance imaging (MRI) was obtained and whether there has been a change in the diagnosis of life-threatening conditions and patient disposition. DESIGN, SETTING, AND PARTICIPANTS Retrospective cross-sectional analysis of emergency department visits using data from the National Hospital Ambulatory Medical Care Survey (1998-2007). Sampled visits were weighted to produce estimates for the United States. MAIN OUTCOMES MEASURES Proportion of visits for injury-related conditions during which a CT or MRI was obtained, a life-threatening condition was diagnosed (eg, cervical spine fracture, skull fracture, intracranial bleeding, liver and spleen laceration), and which resulted in hospital and intensive care unit admission. RESULTS The prevalence of CT or MRI use during emergency department visits for injury-related conditions increased from 6% (95% confidence interval [CI], 5%-7%) (257 of 5237 visits) in 1998 to 15% (95% CI, 14%-17%) (981 of 6567 visits) in 2007 (P < .001 for trend). There was a small increase in the prevalence of life-threatening conditions (1.7% [95% CI, 1.2%-2.2%; 89 of 5237 visits] in 1998 and 2.0% [95% CI, 1.6%-2.5%; 142 of 6567 visits] in 2007; P=.04 for trend) [corrected].There was no change in prevalence of visits during which patients were either admitted to the hospital (5.9% [95% CI, 4.9%-6.9%] in 1998 and 5.5% [95% CI, 4.7%-6.5%] in 2007; P = .50 for trend) or to an intensive care unit (0.62% [95% CI, 0.40%-1.00%] in 1998 and 0.80% [95% CI, 0.53%-1.21%] in 2007; P = .14 for trend). Visits during which CT or MRI was obtained lasted 126 minutes (95% CI, 123-131 minutes) longer than those for which CT or MRI was not obtained. CONCLUSION From 1998 to 2007, the prevalence of CT or MRI use during emergency department visits for injury-related conditions increased significantly, without an equal increase in the prevalence of life-threatening conditions.

Percutaneous Coronary Intervention Versus Optimal Medical Therapy in Stable Coronary Artery Disease A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background— The role of percutaneous coronary intervention (PCI) in the management of stable coronary artery disease remains controversial. Given advancements in medical therapies and stent technology over the last decade, we sought to evaluate whether PCI, when added to medical therapy, improves outcomes when compared with medical therapy alone. Methods and Results— We performed a systematic review and meta-analysis, searching PubMed, EMBASE, and CENTRAL databases, until January 2012, for randomized clinical trials comparing revascularization with PCI to optimal medical therapy (OMT) in patients with stable coronary artery disease. The primary outcome was all-cause mortality, and secondary outcomes included cardiovascular death, nonfatal myocardial infarction, subsequent revascularization, and freedom from angina. Primary analyses were based on longest available follow-up with secondary analyses stratified by trial duration, with short-term (⩽1 year), intermediate (1–5 years), and long-term (≥5 years) time points. We identified 12 randomized clinical trials enrolling 7182 participants who fulfilled our inclusion criteria. For the primary analyses, when compared with OMT, PCI was associated with no significant improvement in mortality (risk ratio [RR], 0.85; 95% CI, 0.71–1.01), cardiac death (RR, 0.71; 95% CI, 0.47–1.06), nonfatal myocardial infarction (RR, 0.93; 95% CI, 0.70–1.24), or repeat revascularization (RR, 0.93; 95% CI, 0.76–1.14), with consistent results over all follow-up time points. Sensitivity analysis restricted to studies in which there was >50% stent use showed attenuation in the effect size for all-cause mortality (RR, 0.93; 95% CI, 0.78–1.11) with PCI. However, for freedom from angina, there was a significant improved outcome with PCI, as compared with the OMT group (RR, 1.20; 95% CI, 1.06–1.37), evident at all of the follow-up time points. Conclusions— In this most rigorous and comprehensive analysis in patients with stable coronary artery disease, PCI, as compared with OMT, did not reduce the risk of mortality, cardiovascular death, nonfatal myocardial infarction, or revascularization. PCI, however, provided a greater angina relief compared with OMT alone, larger studies with sufficient power are required to prove this conclusively.

Preparing the United States for high-sensitivity cardiac troponin assays.

It is only a matter of time before the use of high-sensitivity cardiac troponin assays (hs-cTn) becomes common throughout the United States. In preparation for this inevitability, this article raises a number of important issues regarding these assays that deserve consideration. These include: the need for the adoption of a universal nomenclature; the importance of defining uniform criteria for reference populations; the challenge of discriminating between acute and nonacute causes of hs-cTn elevations, and between type 1 and type 2 acute myocardial infarction (AMI); factors influencing the analytical precision of hs-cTn; ascertaining the optimal duration of the rule-out period for AMI; the need for further evaluation to determine the causes of a positive hs-cTn in non-AMI patients; and the use of hs-cTn to risk-stratify patients with disease conditions other than AMI. This review elaborates on these critical issues as a means of educating clinicians and researchers about them.

Teaching and Assessing Procedural Skills Using Simulation: Metrics and Methodology

Simulation allows educators to develop learner-focused training and outcomes-based assessments. However, the effectiveness and validity of simulation-based training in emergency medicine (EM) requires further investigation. Teaching and testing technical skills require methods and assessment instruments that are somewhat different than those used for cognitive or team skills. Drawing from work published by other medical disciplines as well as educational, behavioral, and human factors research, the authors developed six research themes: measurement of procedural skills; development of performance standards; assessment and validation of training methods, simulator models, and assessment tools; optimization of training methods; transfer of skills learned on simulator models to patients; and prevention of skill decay over time. The article reviews relevant and established educational research methodologies and identifies gaps in our knowledge of how physicians learn procedures. The authors present questions requiring further research that, once answered, will advance understanding of simulation-based procedural training and assessment in EM.

Trends in Imaging Use During the Emergency Department Evaluation of Flank Pain

PURPOSE Patients with acute flank pain or kidney pain are most commonly evaluated in the emergency department with computerized tomography. Currently our understanding of radiographic practice patterns in emergency imaging for flank pain is limited. We characterized the use of conventional radiography (x-ray), ultrasound and computerized tomography in the emergency department evaluation of patients with acute flank pain. MATERIALS AND METHODS We performed a retrospective, cross-sectional analysis of emergency department visits using data on 2000 to 2008 from the National Hospital Ambulatory Medical Care Survey. Specific visits for a complaint of flank or kidney pain were further analyzed. RESULTS During the study period there was a significant increase in computerized tomography use (p <0.0001) and a significant decrease in x-ray use (p = 0.035) while ultrasound use remained stable (p = 0.803). During that period the proportion of patients with flank pain who were diagnosed with a kidney stone remained stable at approximately 20% (p = 0.135). CONCLUSIONS Between 2000 and 2008 there was a significant increase in computerized tomography use for the emergency evaluation of patients with flank pain.

Determination of Unique Microbial Volatile Organic Compounds Produced by Five Aspergillus Species Commonly Found in Problem Buildings

This study identified unique microbial volatile organic compounds (UMVOCs) produced by five Aspergillus species (A. fumigatus, A. versicolor, A. sydowi, A. flavus, and A. niger) cultivated on malt extract agar and gypsum board. The hypothesis was that UMVOCs can be used to predict the presence of Aspergillus species. During the cultivation humidified air was continually supplied and evenly distributed through each of the culture flasks. Volatile metabolites were collected using Tenax TA tubes on Days 8, 16, and 30 after inoculation. The volatile metabolites were determined by gas chromatography/mass spectroscopy after thermal desorption. Nine compounds recognized as UMVOCs--3-methyl-1-butanol; 2-methyl-1-propanol; terpineol; 2-heptanone; 1-octen-3-ol; dimethyl disulfide; 2-hexanone; 3-octanone; and 2-pentylfuran--were found on the cultures in detectable amounts. The first two compounds were detected at the highest frequency when combining both media. The first four compounds were found to be the dominant UMVOCs on gypsum board, which could be used as chemical markers of the common Aspergillus species grown indoors.

Circulating Brain-Derived Neurotrophic Factor Has Diagnostic and Prognostic Value in Traumatic Brain Injury.

Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and regeneration. We investigated the diagnostic and prognostic values of serum BDNF in traumatic brain injury (TBI). We examined serum BDNF in two independent cohorts of TBI cases presenting to the emergency departments (EDs) of the Johns Hopkins Hospital (JHH; n = 76) and San Francisco General Hospital (SFGH, n = 80), and a control group of JHH ED patients without TBI (n = 150). Findings were subsequently validated in the prospective, multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) Pilot study (n = 159). We investigated the association between BDNF, glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase-L1 (UCH-L1) and recovery from TBI at 6 months in the TRACK-TBI Pilot cohort. Incomplete recovery was defined as having either post-concussive syndrome or a Glasgow Outcome Scale Extended score <8 at 6 months. Median day-of-injury BDNF concentrations (ng/mL) were lower among TBI cases (JHH TBI, 17.5 and SFGH TBI, 13.8) than in JHH controls (60.3; p = 0.0001). Among TRACK-TBI Pilot subjects, median BDNF concentrations (ng/mL) were higher in mild (8.3) than in moderate (4.3) or severe TBI (4.0; p = 0.004. In the TRACK-TBI cohort, the 75 (71.4%) subjects with very low BDNF values (i.e., <the 1st percentile for non-TBI controls, <14.2 ng/mL) had higher odds of incomplete recovery than those who did not have very low values (odds ratio, 4.0; 95% confidence interval [CI]: 1.5-11.0). The area under the receiver operator curve for discriminating complete and incomplete recovery was 0.65 (95% CI: 0.52-0.78) for BDNF, 0.61 (95% CI: 0.49-0.73) for GFAP, and 0.55 (95% CI: 0.43-0.66) for UCH-L1. The addition of GFAP/UCH-L1 to BDNF did not improve outcome prediction significantly. Day-of-injury serum BDNF is associated with TBI diagnosis and also provides 6-month prognostic information regarding recovery from TBI. Thus, day-of-injury BDNF values may aid in TBI risk stratification.

Emergency department evaluation of traumatic brain injury in the United States, 2009-2010

Objective:To determine the dimensions of traumatic brain injury (TBI) evaluation in US emergency department (EDs) to inform potential application of novel diagnostic tests. Setting:US EDs. Participants:National Hospital Ambulatory Medical Care Survey of ED visits in 2009 and 2010 where TBI was evaluated (1) and diagnosed either clinically or (2) with head computed tomographic (CT) scans. Design:Retrospective cross-sectional. Results:TBI was evaluated during 4.8 (95% confidence interval [CI], 4.2-5.4) million visits per year; and head CT scan was performed in 82% of TBI evaluations (3.9 [95% CI, 3.4-4.4] million visits per year). TBI was diagnosed in 52% of evaluations (2.5 [95% CI, 2.1-2.8] million visits per year). Among those who received head CT scans, 9% had CT evidence of traumatic abnormalities. Among patients evaluated for TBI who had a Glasgow Coma Scale score recorded, 94.5% were classified as having mild TBI, 2.1% as moderate TBI, and 3.5% as severe TBI. Among patients with International Classification of Diseases, Ninth Revision, Clinical Modification, codes permitting the calculation of head Abbreviated Injury Scale scores 9.0%, 85.0%, 2.5%, 3.2%, 0.3%, and 0% had head Abbreviated Injury Scale scores of 1, 2, 3, 4, 5, and 6, respectively. Of patients evaluated for TBI, 31% had other head/face/neck injuries, 10% had spine and back injuries, 7% had torso injuries, and 14% had extremity injuries. Conclusion:The ED is the main gateway to medical care for millions of patients evaluated for TBI each year. Novel diagnostic tests are needed to improve ED diagnosis and management of TBI.

Troponin Elevations Only Detected With a High-sensitivity Assay: Clinical Correlations and Prognostic Significance

OBJECTIVES With clinical use of high-sensitivity troponin I (hsTnI), more frequent troponin elevations will occur. However, the burden and implications of these elevations are not well understood. The authors quantified the prevalence of elevated hsTnI in patients presenting with possible acute coronary syndrome (ACS) who do not have elevated troponin with a current generation assay (cardiac troponin I [cTnI]) and determined the association of these newly detected elevations with a composite of all-cause mortality and subsequent cardiac hospitalization. METHODS This was a prospective observational study of 808 subjects evaluated for possible ACS and followed for up to 1 year. Troponin values were measured with hsTnI (Abbott Laboratories) and cTnI (Abbott and Beckman Coulter). Cardiac hospitalization was defined as hospitalization for ACS, revascularization, acute heart failure (AHF), or tachy/brady arrhythmia that occurred after the index emergency department (ED) visit or hospital discharge. RESULTS Forty subjects (5%) were diagnosed with ACS (26 myocardial infarction and 14 unstable angina). On the initial sample, the prevalence of elevated hsTnI among subjects with nonelevated cTnI was 9.2% using a gender-neutral cutoff (95% confidence interval [CI] = 7.1% to 11.4%) and 11.1% using a gender-specific cutoff (95% CI = 8.8% to 13.4%). Adjudicated diagnoses for subjects whose initial samples had elevated hsTnI but nonelevated cTnI (gender-neutral cutoff) were as follows: three (4.6%) ACS, 15 (23.1%) AHF, three (4.6%) volume overload etiology unclear/noncardiac, three (4.6%) cardiac (non-ACS), and 41 (63.1%) other. Of the 65 patients whose initial samples had hsTnI but nonelevated cTnI, eight developed cTnI elevation on subsequent serial sampling. After traditional cardiovascular risk factors and renal function were adjusted for, subjects with elevated initial hsTnI but nonelevated cTnI (initial and serial sampling) had a higher risk of all-cause mortality and subsequent cardiac hospitalization than subjects with both nonelevated hsTnI and nonelevated cTnI (hazard ratio [HR] = 1.91, 95% CI = 1.14 to 3.19). CONCLUSIONS On the initial sample, 9% to 11% of subjects without cTnI elevation had hsTnI elevation. Although the majority of the patients with these newly detected hsTnI elevations did not have ACS, they had a higher risk for all-cause mortality and subsequent cardiac hospitalization.

Association of high-sensitivity cardiac troponin I concentration with cardiac outcomes in patients with suspected acute coronary syndrome

Importance High-sensitivity cardiac troponin I testing is widely used to evaluate patients with suspected acute coronary syndrome. A cardiac troponin concentration of less than 5 ng/L identifies patients at presentation as low risk, but the optimal threshold is uncertain. Objective To evaluate the performance of a cardiac troponin I threshold of 5 ng/L at presentation as a risk stratification tool in patients with suspected acute coronary syndrome. Data Sources Systematic search of MEDLINE, EMBASE, Cochrane, and Web of Science databases from January 1, 2006, to March 18, 2017. Study Selection Prospective studies measuring high-sensitivity cardiac troponin I concentrations in patients with suspected acute coronary syndrome in which the diagnosis was adjudicated according to the universal definition of myocardial infarction. Data Extraction and Synthesis The systematic review identified 19 cohorts. Individual patient-level data were obtained from the corresponding authors of 17 cohorts, with aggregate data from 2 cohorts. Meta-estimates for primary and secondary outcomes were derived using a binomial-normal random-effects model. Main Outcomes and Measures The primary outcome was myocardial infarction or cardiac death at 30 days. Performance was evaluated in subgroups and across a range of troponin concentrations (2-16 ng/L) using individual patient data. Results Of 11 845 articles identified, 104 underwent full-text review, and 19 cohorts from 9 countries were included. Among 22 457 patients included in the meta-analysis (mean age, 62 [SD, 15.5] years; n = 9329 women [41.5%]), the primary outcome occurred in 2786 (12.4%). Cardiac troponin I concentrations were less than 5 ng/L at presentation in 11 012 patients (49%), in whom there were 60 missed index or 30-day events (59 index myocardial infarctions, 1 myocardial infarction at 30 days, and no cardiac deaths at 30 days). This resulted in a negative predictive value of 99.5% (95% CI, 99.3%-99.6%) for the primary outcome. There were no cardiac deaths at 30 days and 7 (0.1%) at 1 year, with a negative predictive value of 99.9% (95% CI, 99.7%-99.9%) for cardiac death. Conclusions and Relevance Among patients with suspected acute coronary syndrome, a high-sensitivity cardiac troponin I concentration of less than 5 ng/L identified those at low risk of myocardial infarction or cardiac death within 30 days. Further research is needed to understand the clinical utility and cost-effectiveness of this approach to risk stratification.