Accuracy of Emergency Department Chest Pain Patients' Reporting of Coronary Disease History.

Introduction: History is an important component of emergency department risk stratification for chest pain patients. We hypothesized that a significant portion of patients would not be able to accurately report their history of coronary artery disease (CAD) and diagnostic testing. Methods: We prospectively enrolled a convenience sample of a cohort of adult ED patients with a chief complaint of chest pain. They completed a structured survey that included questions regarding prior testing for CAD and cardiac history. Study authors performed a structured chart review within the electronic medical record for our 6-hospital system. Results of testing for CAD, cardiac interventions, and chart diagnoses of CAD/acute myocardial infarction (AMI) were recorded. Categorical data were analyzed by Chi-square and continuous data by logistic regression. Results: About 196 patients were enrolled; mean age 57 ± 15 years, 48% female, 67% Hispanic, 50% income <$20,000/year. About 43% (95% confidence interval [CI] 35%-51%) of patients stated that they did not have CAD, yet medical records indicated that they were CAD+. With increasing age, patients were more likely to accurately report the absence of CAD (P < 0.001). There was no association between patients reporting no CAD, but CAD+ in records with respect to the following characteristics: female gender (P = 0.37), Hispanic race (P = 0.73), income (P = 0.41), less than or equal to high school education (P = 0.11), and private insurance (P = 0.71). For patients with prior AMI, 7.2% (95% CI 2.7%-11%) reported no prior history of AMI. Conclusions: Within our study group from a predominantly poor, Hispanic population, patients had a poor recall for the presence of CAD in their medical history.

Predictive Value of Point-of-care Lactate Measurement in Patients Meeting Level II and III Trauma Team Activation Criteria that Present to the Emergency Department: A Prospective Study.

BACKGROUND: The aim of this study was to investigate the utility of early point-of-care (POC) lactate levels to help predict injury severity and ultimate emergency department (ED) disposition for trauma patients meeting Level II and III activation criteria. METHODS: This was a blinded, prospective cohort study including a convenience sample of patients meeting our triage criteria for Level II or III team activation with stable vital signs. Bedside lactate samples were collected during the secondary survey. Clinical care/disposition was at the discretion of physicians who remained blinded to the bedside lactate result. An elevated lactate was defined as >2.0 mmol/L. RESULTS: Ninety-six patients were in the study group; mean age was 41 ± 17 years, 26% were female, 57% were Hispanic, and 60% admitted. We found no difference in initial mean POC lactate levels (mmol/L) for admitted versus discharged groups and Injury Severity Score (ISS) ≥9 versus ISS <9 groups (3.71 [95% confidence interval (CI): 3.1-4.4] vs. 3.85 [95% CI: 2.8-4.9]; P = 0.99 and 3.54 [95% CI: 2.7-4.4] vs. 3.89 [95% CI: 3.1-4.6]; P = 0.60, respectively). Performance characteristics of early elevated lactate levels were poor both to predict need for hospital admission (sensitivity = 77% [65%-87%]; specificity = 26% [13%-43%]; negative predictive value [NPV] = 43% [27%-61%]; and positive predictive value [PPV] = 62% [56%-67%]) and to identify patients with ISS scores ≥9 (sensitivity = 76% [59%-89%]; specificity = 24% [14%-37%]; NPV = 65% [47%-80%]; and PPV = 36% [30%-41%]). CONCLUSIONS: For Level II/III, we found that early bedside lactate levels were not predictive of ISS ≥9 or the need for admission. LEVEL OF EVIDENCE: III (diagnostic test).

The Influence of Cervical Collar Immobilization on Optic Nerve Sheath Diameter.

BACKGROUND: Prior research has revealed that cervical collars elevate intracranial pressure (ICP) in patients with traumatic brain injury. Two recent small studies evaluated the change in optic sheath nerve diameter (ONSD) measured by ultrasound as a proxy for ICP following cervical collar placement in healthy volunteers. OBJECTIVE: We sought to validate the finding that ONSD measured by ultrasound increases after cervical collar placement within an independent data set. METHODS: This was a prospective, crossover study involving volunteers. Participants were randomized to either have the ONSD measured first without a cervical collar or initially with a cervical collar. Two sonographers performed independent ONSD diameter measurements. Continuous data were analyzed by matched-paired t-tests. Alpha was set at 0.05. The primary outcome parameter was the overall mean difference between ONSD measurements with the cervical collar on and off. Multiple linear regression was performed to examine the relationship between variables and the primary outcome parameter. RESULTS: There were 30 participants enrolled in the study. Overall mean ONSD for participants without the collar was 0.365 ± 0.071 cm and with the collar was 0.392 ± 0.081 cm. The mean change in ONSD for participants with and without the collar was 0.026 ± 0.064 cm (95% confidence interval of difference: 0.015-0.038; P < 0.001). Multiple regression analysis did not identify any variables associated with the variation in ONSD observed for collar versus noncollar. CONCLUSIONS: We confirmed that ONSD does vary by a measurable amount with placement of a rigid cervical collar on healthy volunteers when assessed by ultrasound.

Costs and Characteristics of Undocumented Immigrants Brought to a Trauma Center by Border Patrol Agents in Southern Texas.

BACKGROUND: The objective of this study was to evaluate the costs, characteristics, and outcomes of patients brought to a Texas trauma center emergenct department after apprehension by Border Patrol (BP)/Immigration and Customs Enforcement (BP/ICE). MATERIALS AND METHODS: This is a secondary analysis of a trauma registry/financial records (1/1/11-12/31/14). Data were extracted utilizing a structured form. A multivariate ordinary least square was estimated to identify variables associated with hospital charges. RESULTS: A total of 128 patients were enrolled as the study group; mean age was 28.6 ± 6 years, 20.3% were female, 100% were Hispanic, the most common mechanism of injury (MOI) was motor vehicle crash (75%), and mean charge was $162,152 ± $295,441. Mean length of stay (LOS) was 13.2 ± 29.8 days; 92.2% survived to discharge. Bivariate analysis revealed that MOI differed by gender (P = 0.021). In the multivariate analysis, the only variable that associated with increased charge was LOS. Total charges for the 128 patients were $20.6M, total costs were $4.5M, and total payments were $0.99M. CONCLUSIONS: Undocumented immigrants apprehended by BP/ICE and brought to our trauma center utilized significant health-care resources.

A Comparison of Nonobese Versus Obese Emergency Department Patient Satisfaction Scores Utilizing Standard U.S. Hospital Survey Query Methodology.

BACKGROUND: Prior research reveals that overweight patients have higher emergency department (ED) utilization rates, longer length of stay, and face increased misdiagnosis risk. OBJECTIVE: The objective of this study was to evaluate the association between obesity and ED patient satisfaction. METHODS: This study was a cross-sectional study. A convenience sample of inner-city ED patients completed a written survey, then rated overall satisfaction with ED care (10-point scale), and rated components of satisfaction (4-point scale; never to always). Body mass index (BMI) was calculated using triage records (obesity = BMI >30). RESULTS: Five hundred and sixty-four patients were included in the study group (50.5%: obese, 55.4%: female, mean age: 43.2 ± 25.4 years). With respect to overall visit satisfaction (rating 8 or greater on 10-point scale), bivariate analysis revealed no differences between nonobese versus obese patients (74.6% vs. 73.9%; P = 0.85). There were no significant differences for score of 4 (always) for components of ED satisfaction: physician courtesy (87.9% vs. 90.4%; P = 0.34), nurse courtesy/respect (89.2% vs. 88.7%; P = 0.87), doctor listened (85.4% vs. 87.1%; P = 0.5), doctor explained (80.2% vs. 85.0%; P = 0.14), and recommend to friend (72.5% vs. 81.1%; P = 0.02). Within our multivariate model, obesity was not associated with overall satisfaction (scores of 8 or greater) (P = 0.97; odds ratio = 0.99 [95% confidence interval = 0.65-1.5]). CONCLUSIONS: Despite research that suggests that overweight patients have characteristics of their ED visit that might increase dissatisfaction risk, we found no difference in satisfaction scores between nonobese and obese patients.

Use of a Dental Vibration Tool to Reduce Pain From Digital Blocks: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: The infiltration of local anesthetic is consistently described as painful by patients. Vibration anesthesia has been studied in the dental literature as a promising tool to alleviate the pain from dental nerve blocks. Many of these studies used a specific device, the DentalVibe. To date, there have not been any studies applying this technology to digital blocks of the hand in human subjects. We hypothesized that the use of microvibratory stimulation during digital blocks of the hand would decrease pain reported by patients. METHODS: This was a randomized controlled trial of consenting adult emergency department patients who received digital block anesthesia for hand digit therapy when study authors were present. The study period was 24 months at an academic emergency department. A sample size of 50 injections (25 subjects) was necessary for a power of 80% to detect a mean difference of 2 (SD, 2.5) on the pain scale. A 2-sided dorsal injection approach was used for digital blocks. Subjects were randomized to either intervention (vibration) for the first injection or sham (device off). Both intervention and sham were held in place for 5 seconds prior to and during injection. Subjects were given 2 mL of 1% lidocaine and asked to rate the injection pain on a 1- to 10-point scale. This process was then repeated. Mean pain scores were compared using paired t tests. Our primary outcome was the difference in mean injection pain score between sham versus intervention groups. RESULTS: There were 25 patients in the study group (mean age, 35.52 years [range, 18-58 years]; 8 females; 11 non-Hispanic white). The mean injection pain score in the sham group was 4.28 (95% confidence interval [CI], 3.14-5.42), and in the intervention group, the mean pain score was 2.52 (95% CI, 1.62-3.42). For the primary outcome, the mean injection pain score difference between the sham and intervention groups across all subjects was 1.76 (95% CI, 0.49-3.03; P = 0.009). The mean injection pain score differences were similar across groups: females versus males (0.24; 95% CI, -2.31 to 2.79; P = 0.85), non-Hispanic whites versus other races (0.76; 95% CI, -1.78 to 3.29; P = 0.54), intervention first versus sham first (-0.43; 95% CI, -3.25 to 2.40; P = 0.75). CONCLUSIONS: Our results show a statistically significant difference in mean injection pain score during digital block of the hand when the DentalVibe device is used for vibration anesthesia. Larger studies are warranted to confirm our findings.

How much risk are emergency department patients willing to accept to avoid diagnostic testing.

OBJECTIVES: There is a paucity of research evaluating the risk tolerance of Emergency Department (ED) patients. We hypothesized that a significant percentage of ED patients surveyed would be comfortable with ≥5% risk of adverse outcome if they avoided testing in several hypothetical scenarios. MATERIALS AND METHODS: This was a cross-sectional study of a convenience sample of stable inner-city ED patients. Patients completed a written survey and were asked four closed-answer questions regarding risk tolerance/willingness to refuse a test/procedure, including the following scenarios: #1: LP following CT head; #2 overnight serial troponins for rule out myocardial infarction; #3 CT for possible appendicitis, #4 parent deciding whether child should undergo head CT for low risk head injury. Risk preferences were stratified to ≥5% (high) and <5% (low). Multivariate logistic regressions performed for each scenario to control for confounding factors. RESULTS: There were 217 patients in the study group; mean age 42 ± 15 years, 48% female, 66% Hispanic, 87% income < $40,000 income group. A substantial percentage of patients rated high risk tolerance for each scenario, including 31% for #1 (avoid LP), 25% for #2 (avoid cardiac rule-out admission), 27% for #3 (avoid CT for appendicitis), and 19% for #4 (avoid head CT for child). DISCUSSION: For 3 of 4 scenarios, 25% or more of our patients would accept a high risk tolerance of adverse outcome to avoid further testing. CONCLUSION: Our findings contribute further evidence to the growing body of literature supporting patient interest in shared decision making in the ED.

Increased door to admission time is associated with prolonged throughput for ED patients discharged home.

BACKGROUND: Emergency Department (ED) service evaluations are typically based on surveys of discharged patients. Physicians/administrators benefit from data that quantifies system-based factors that adversely impact the experience of those who represent the survey cohort. OBJECTIVE: While investigators have established that admitted patient boarding impacts overall ED throughput times, we sought to specifically quantify the relationship between throughput times for patients admitted (EDLOS) versus discharged home from the ED (DCLOS). METHODS: We performed a prospective analysis of consecutive patient encounters at an inner-city ED. Variables collected: median daily DCLOS for ED patients, ED daily census, left without being seen (LWBS), median door to doctor, median room to doctor, and daily number admitted. Admitted patients divided into 2 groups based on daily median EDLOS for admits (<6 hours, ≥6 hours). Continuous variables analyzed by t-tests. Multivariate regression utilized to identify independent effects of the co-variants on median daily DCLOS. RESULTS: We analyzed 24,127 patient visits. ED patient DCLOS was longer for patients seen on days with prolonged EDLOS (193.7 minutes, 95%CI 186.7-200.7 vs. 152.8, 144.9-160.5, P< .0001). Variables that were associated with increased daily median EDLOS for admits included: daily admits (P= 0.01), room to doctor time (P< .01), number of patients that left without being seen (P< .01). When controlling for the covariate daily census, differences in DCLOS remained significant for the ≥6 hours group (189.4 minutes, 95%CI 184.1-194.7 vs. 164.8, 155.7-173.9 (P< .0001). CONCLUSION: Prolonged ED stays for admitted patients were associated with prolonged throughput times for patients discharged home from the ED.

Are patients who call a primary care office referred to the emergency department by non-healthcare personnel without the input of a physician?

Objective. We hypothesized that a significant percentage of patients who are referred to the Emergency Department (ED) after calling their primary care physician's (PCP) office receive such instructions without the input of a physician. Methods. We enrolled a convenience sample of stable adults at an inner-city ED. Patients provided written answers to structured questions regarding PCP contact prior to the ED visit. Continuous data are presented as means ± standard deviation; categorical data as frequency of occurrence. 95% confidence intervals were calculated. Results. The study group of 660 patients had a mean age of 41.7 ± 14.7 years and 72.6% had income below $20,000/year. 472 patients (71.51%; 67.9%-74.8%) indicated that they had a PCP. A total of 155 patients (23.0%; 19.9%-26.4%) called to contact their PCP prior to ED visit. For patients who called their PCP office and were directed by phone to the ED, the referral pattern was observed as follows: 31/98 (31.63%; 23.2%-41.4%) by a non-health care provider without physician input, 11/98 (11.2%; 6.2%-19.1%) by a non-healthcare provider after consultation with a physician, 12/98 (12.3%; 7.7%-20.3%) by a nurse without physician input, and 14/98 (14.3%; 8.6%-22.7%) by a nurse after consultation with physician. An additional 11/98, 11.2%; 6.2-19.1%) only listened to a recorded message and felt the message was directing them to the ED. Conclusion. A relatively small percentage of patients were referred to the ED without the consultation of a physician in our overall population. However, over half of those that contacted their PCP's office felt directed to the ED by non-health care staff.

Prior CT imaging history for patients who undergo PAN CT for acute traumatic injury.

Objective. A single PAN scan may provide more radiation to a patient than is felt to be safe within a one-year period. Our objective was to determine how many patients admitted to the trauma service following a PAN scan had prior CT imaging within our six-hospital system. Methods. We performed a secondary analysis of a prospectively collected trauma registry. The study was based at a level-two trauma center and five affiliated hospitals, which comprise 70.6% of all Emergency Department visits within a twelve county region of southern Texas. Electronic medical records were reviewed dating from the point of trauma evaluation back to December 5, 2005 to determine evidence of prior CT imaging. Results. There were 867 patients were admitted to the trauma service between January 1, 2012 and December 31, 2012. 460 (53%) received a PAN scan and were included in the study group. The mean age of the study group was 37.7 ± 1.54 years old, 24.8% were female, and the mean ISS score was 13.4 ± 1.07. The most common mechanism of injury was motor vehicle collision (47%). 65 (14%; 95% CI [11-18]%) of the patients had at least one prior CT. The most common prior studies performed were: CT head (29%; 19-42%), CT Face (29%; 19-42%) and CT Abdomen and Pelvis (18%; 11-30%). Conclusion. Within our trauma registry, 14% of patients had prior CT imaging within our hospital system before their traumatic event and PAN scan.

Patient understanding of radiation risk from medical computed tomography-A comparison of Hispanic vs. non-Hispanic emergency department populations.

Background. Cultural differences and language barriers may adversely impact patients with respect to understanding the risks/benefits of medical testing. Objective. We hypothesized that there would be no difference in Hispanic vs. non-Hispanic patients' knowledge of radiation risk that results from CT of the abdomen/pelvis (CTAP). Methods. We enrolled a convenience sample of adults at an inner-city emergency department (ED). Patients provided written answers to rate agreement on a 10-point scale for two correct statements comparing radiation exposure equality between: CTAP and 5 years of background radiation (question 1); CTAP and 200 chest x-rays (question 3). Patients also rated their agreement that multiple CT scans increase the lifetime cancer risk (question 2). Scores of >8 were considered good knowledge. Multivariate logistic regression analyses were performed to estimate the independent effect of the Hispanic variable. Results. 600 patients in the study group; 63% Hispanic, mean age 39.2 ± 13.9 years. Hispanics and non-Hispanics whites were similar with respect to good knowledge-level answers to question 1 (17.3 vs. 15.1%; OR = 1.2; 95% CI [0.74-2.0]), question 2 (31.2 vs. 39.3%; OR = 0.76; 95% CI [0.54-1.1]), and question 3 (15.2 vs. 16.5%; OR = 1.1; 95% CI [0.66-1.8]). Compared to patients who earned <20,000, patients with income >40,000 were more likely to answer question 2 with good knowledge (OR = 1.96; 95% CI [1.2-3.1]). Conclusion. The study group's overall knowledge of radiation risk was poor, but we did not find significant differences between Hispanic vs. non-Hispanic patients.

Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath.

BACKGROUND: Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients. METHODS: A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation. RESULTS: A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%). CONCLUSION: This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes.

Evaluation of pulmonary embolism in the emergency department and consistency with a national quality measure: quantifying the opportunity for improvement.

BACKGROUND: The National Quality Forum (NQF) has endorsed a performance measure designed to increase imaging efficiency for the evaluation of pulmonary embolism (PE) in the emergency department (ED). To our knowledge, no published data have examined the effect of patient-level predictors on performance. METHODS: To quantify the prevalence of avoidable imaging in ED patients with suspected PE, we performed a prospective, multicenter observational study of ED patients evaluated for PE from 2004 through 2007 at 11 US EDs. Adult patients tested for PE were enrolled, with data collected in a standardized instrument. The primary outcome was the proportion of imaging that was potentially avoidable according to the NQF measure. Avoidable imaging was defined as imaging in a patient with low pretest probability for PE, who either did not have a D-dimer test ordered or who had a negative D-dimer test result. We performed subanalyses testing alternative pretest probability cutoffs and imaging definitions on measure performance as well as a secondary analysis to identify factors associated with inappropriate imaging. χ(2) Test was used for bivariate analysis of categorical variables and multivariable logistic regression for the secondary analysis. RESULTS: We enrolled 5940 patients, of whom 4113 (69%) had low pretest probability of PE. Imaging was performed in 2238 low-risk patients (38%), of whom 811 had no D-dimer testing, and 394 had negative D-dimer test results. Imaging was avoidable, according to the NQF measure, in 1205 patients (32%; 95% CI, 31%-34%). Avoidable imaging owing to not ordering a D-dimer test was associated with age (odds ratio [OR], 1.15 per decade; 95% CI, 1.10-1.21). Avoidable imaging owing to imaging after a negative D-dimer test result was associated with inactive malignant disease (OR, 1.66; 95% CI, 1.11-2.49). CONCLUSIONS: One-third of imaging performed for suspected PE may be categorized as avoidable. Improving adherence to established diagnostic protocols is likely to result in significantly fewer patients receiving unnecessary irradiation and substantial savings.

Factors associated with positive D-dimer results in patients evaluated for pulmonary embolism.

OBJECTIVES: Available D-dimer assays have low specificity and may increase radiographic testing for pulmonary embolism (PE). To help clinicians better target testing, this study sought to quantify the effect of risk factors for a positive quantitative D-dimer in patients evaluated for PE. METHODS: This was a prospective, multicenter, observational study. Emergency department (ED) patients evaluated for PE with a quantitative D-dimer were eligible for inclusion. The main outcome of interest was a positive D-dimer. Odds ratio (ORs) and 95% confidence intervals (CIs) were determined by multivariable logistic regression. Adjusted estimates of relative risk were also calculated. RESULTS: A total of 4,346 patients had D-dimer testing, of whom 2,930 (67%) were women. A total of 2,500 (57%) were white, 1,474 (34%) were black or African American, 238 (6%) were Hispanic, and 144 (3%) were of other race or ethnicity. The mean (+/-SD) age was 48 (+/-17) years. Overall, 1,903 (44%) D-dimers were positive. Model fit was adequate (c-statistic = 0.739, Hosmer and Lemeshow p-value = 0.13). Significant positive predictors of D-dimer positive included female sex; increasing age; black (vs. white) race; cocaine use; general, limb, or neurologic immobility; hemoptysis; hemodialysis; active malignancy; rheumatoid arthritis; lupus; sickle cell disease; prior venous thromboembolism (VTE; not under treatment); pregnancy and postpartum state; and abdominal, chest, orthopedic, or other surgery. Warfarin use was protective. In contrast, several variables known to be associated with PE were not associated with positive D-dimer results: body mass index (BMI), estrogen use, family history of PE, (inactive) malignancy, thrombophilia, trauma within 4 weeks, travel, and prior VTE (under treatment). CONCLUSIONS: Many factors are associated with a positive D-dimer test. The effect of these factors on the usefulness of the test should be considered prior to ordering a D-dimer.

Clinical features from the history and physical examination that predict the presence or absence of pulmonary embolism in symptomatic emergency department patients: results of a prospective, multicenter study.

STUDY OBJECTIVE: Prediction rules for pulmonary embolism use variables explicitly shown to estimate the probability of pulmonary embolism. However, clinicians often use variables that have not been similarly validated, yet are implicitly believed to modify probability of pulmonary embolism. The objective of this study is to measure the predictive value of 13 implicit variables. METHODS: Patients were enrolled in a prospective cohort study from 12 centers in the United States; all had an objective test for pulmonary embolism (D-dimer, computed tomographic angiography, or ventilation-perfusion scan). Clinical features including 12 predefined previously validated (explicit) variables and 13 variables not part of existing prediction rules (implicit) were prospectively recorded at presentation. The primary outcome was venous thromboembolism (pulmonary embolism or deep venous thrombosis), diagnosed by imaging up to 45 days after enrollment. Variables with adjusted odds ratios from logistic regression with 95% confidence intervals not crossing unity were considered significant. RESULTS: Seven thousand nine hundred forty patients (7.2% venous thromboembolism positive) were enrolled. Mean age was 49 years (standard deviation 17 years) and 67% were female patients. Eight of 13 implicit variables were significantly associated with venous thromboembolism; those with an adjusted odds ratio (OR) greater than 1.5 included non-cancer-related thrombophilia (OR 1.99), pleuritic chest pain (OR 1.53), and family history of venous thromboembolism (OR 1.51). Implicit variables that predicted no venous thromboembolism outcome included substernal chest pain, female sex, and smoking. Nine of 12 explicit variables predicted a positive outcome of venous thromboembolism, including patient history of pulmonary embolism or deep venous thrombosis in the past, unilateral leg swelling, recent surgery, estrogen, hypoxemia, and active malignancy. CONCLUSION: In symptomatic outpatients being considered for possible pulmonary embolism, non-cancer-related thrombophilia, pleuritic chest pain, and family history of venous thromboembolism increase probability of pulmonary embolism or deep venous thrombosis. Other variables that are part of existing pretest probability systems were validated as important predictors in this diverse sample of US emergency department patients.

12-lead ECG findings of pulmonary hypertension occur more frequently in emergency department patients with pulmonary embolism than in patients without pulmonary embolism.

STUDY OBJECTIVE: Acute pulmonary embolism can produce abnormalities on ECG that reflect severity of pulmonary hypertension. Early recognition of these findings may alter the estimated pretest probability of pulmonary embolism and prompt more aggressive treatment before hemodynamic instability ensues, but it is first important to test whether these findings are specific to patients with pulmonary embolism. We hypothesize that ECG findings consistent with pulmonary hypertension would be observed more frequently in patients with pulmonary embolism. METHODS: Secondary analysis of a prospective, observational cohort of emergency department patients who were tested for pulmonary embolism. ECGs were ordered at clinician's discretion and interpreted at presentation. RESULTS: Six thousand forty-nine patients had an ECG, 354 (5.9%) of whom were diagnosed with pulmonary embolism. The frequency, positive likelihood ratio (LR+) and 95% confidence interval (CI) of each predictor were as follows: S1Q3T3 8.5% with pulmonary embolism versus 3.3% without pulmonary embolism (LR+ 3.7; 95% CI 2.5 to 5.4); nonsinus rhythm, 23.5% versus 16.6% (LR+ 1.4; 95% CI 1.2 to 1.7); inverted T waves in V1 to V2, 14.4% versus 8.1% (LR+ 1.8; 95% CI 1.3 to 2.3); inversion in V1 to V3, 10.5% versus 4.0% (LR+ 2.6; 95% CI 1.9 to 3.6); inversion in V1 to V4, 7.3% versus 2.0% (LR+ 3.7; 95% CI 2.4 to 5.5); incomplete right bundle branch block, 4.8% versus 2.8% (LR+ 1.7; 95% CI 1.0 to 2.7); tachycardia (pulse rate >100 beats/min), 28.8% versus 15.7% (LR+ 1.8; 95% CI 1.5 to 2.2). Likelihood ratios and specificities were similar when patients with previous cardiopulmonary disease were excluded from analysis. CONCLUSION: Findings of acute pulmonary hypertension were infrequent overall but were observed more frequently in patients with the final diagnosis of pulmonary embolism compared with patients who do not have pulmonary embolism.

Potential impact of adjusting the threshold of the quantitative D-dimer based on pretest probability of acute pulmonary embolism.

OBJECTIVES: The utility of D-dimer testing for suspected pulmonary embolism (PE) can be limited by test specificity. The authors tested if the threshold of the quantitative D-dimer can be varied according to pretest probability (PTP) of PE to increase specificity while maintaining a negative predictive value (NPV) of >99%. METHODS: This was a prospective, observational multicenter study of emergency department (ED) patients in the United States. Eligible patients had a diagnostic study ordered to evaluate possible PE. PTP was determined by the clinician's unstructured estimate and the Wells score. Five different D-dimer assays were used. D-dimer test performance was measured using 1) standard thresholds and 2) variable threshold values: twice (for low PTP patients), equal (intermediate PTP patients), or half (high PTP patients) of standard threshold. Venous thromboembolism (VTE) within 45 days required positive imaging plus decision to treat. RESULTS: The authors enrolled 7,940 patients tested for PE, and clinicians ordered a quantitative D-dimer for 4,357 (55%) patients who had PTPs distributed as follows: low (74%), moderate (21%), or high (4%). At standard cutoffs, across all PTP strata, quantitative D-dimer testing had a test sensitivity of 94% (95% confidence interval [CI] = 91% to 97%), specificity of 58% (95% CI = 56% to 60%), and NPV of 99.5% (95% CI = 99.1% to 99.7%). If variable cutoffs had been used the overall sensitivity would have been 88% (95% CI = 83% to 92%), specificity 75% (95% CI = 74% to 76%), and NPV 99.1% (95% CI = 98.7% to 99.4%). CONCLUSIONS: This large multicenter observational sample demonstrates that emergency medicine clinicians currently order a D-dimer in the majority of patients tested for PE, including a large proportion with intermediate PTP and high PTP. Varying the D-dimer's cutoff according to PTP can increase specificity with no measurable decrease in NPV.

Risk of thromboembolism varies, depending on category of immobility in outpatients.

STUDY OBJECTIVE: Immobility predisposes to venous thromboembolism, but this risk may vary, depending on the underlying cause of immobility. METHODS: This was a prospective, longitudinal outcome study of self-presenting emergency department (ED) patients who were from 12 hospitals and had suspected venous thromboembolism. Using explicit written criteria, clinicians recorded clinical features of each patient in the ED by using a Web-based data form. The form required one of 6 types of immobility: no immobility, general or whole-body immobility greater than 48 hours, limb (orthopedic) immobility, travel greater than 8 hours causing immobility within the previous 7 days, neurologic paralysis, or other immobility not listed above. Patients were followed for 45 days for outcome of venous thromboembolism, which required positive imaging results and clinical plan to treat. Odds ratios (ORs) were derived from logistic regression including 12 covariates. RESULTS: From 7,940 patients enrolled, 545 of 7,940 (6.9%) were diagnosed with venous thromboembolism (354 pulmonary embolism, 72 deep venous thrombosis, 119 pulmonary embolism and deep venous thrombosis). Risk of venous thromboembolism varied, depending on immobility type: limb (OR=2.24; 95% confidence interval [CI] 1.40 to 3.60), general (OR=1.76; 95% CI 1.26 to 2.44), other (OR=1.97; 95% CI 1.25 to 3.09), neurologic (OR=2.23; 95% CI 1.01 to 4.92), and travel (OR=1.19; 95% CI 0.85 to 1.67). Other significant risk factors from multivariate analysis included age greater than 50 years (OR =1.5; 95% CI 1.25 to 1.82), unilateral leg swelling (OR=2.68; 95% CI 2.13 to 3.37), previous venous thromboembolism (OR=2.99; 95% CI 2.41 to 3.71), active malignancy (OR=2.23; 95% CI 1.69 to 2.95), and recent surgery (OR=2.12; 95% CI 1.61 to 2.81). CONCLUSION: In a large cohort of symptomatic ED patients, risk of venous thromboembolism was substantially increased by presence of limb, whole-body, or neurologic immobility but not by travel greater than 8 hours. These data show the importance of clarifying the cause of immobility in risk assessment of venous thromboembolism.

Independent evaluation of an out-of-hospital termination of resuscitation (TOR) clinical decision rule.

OBJECTIVES: Recently, investigators described a clinical decision rule for termination of resuscitation (TOR) designed to help determine whether to terminate emergency medical services (EMS) resuscitative efforts for out-of-hospital cardiac arrests (OOHCA). The authors sought to evaluate the hypothesis that TOR would predict no survival for patients in an independent cohort of patients with OOHCA. METHODS: This was a retrospective cohort analysis conducted in the state of Arizona. Consecutive, adult, OOHCA were prospectively evaluated from October 2004 through October 2006. A statewide OOHCA database utilizing Utstein-style reporting from 30 different EMS systems was used. Data were abstracted from EMS first care reports and hospital discharge records. The TOR guidelines predict that no survival to hospital discharge will occur if 1) an OOHCA victim does not have return of spontaneous circulation (ROSC), 2) no shocks are administered, and 3) the arrest is not witnessed by EMS personnel. Data were entered into a structured database. Continuous data are presented as means (+/-standard deviations [SD]) and categorical data as frequency of occurrence, and 95% confidence intervals (CIs) were calculated as appropriate. The primary outcome measure was to determine if any cohort member who met TOR criteria survived to hospital discharge. RESULTS: There were 2,239 eligible patients; the study group included 2,180 (97.4%) patients for whom the data were complete; mean age was 64 (+/-11) years, and 35% were female. The majority of patients in the study group met at least one or more of the TOR criteria. A total of 2,047 (93.8%) patients suffered from cardiac arrest that was unwitnessed by EMS; 1,653 (75.8%) had an unwitnessed arrest and no ROSC. With respect to TOR, 1,160 of 2,180 (53.2%) patients met all three criteria; only one (0.09%; 95% CI = 0% to 0.5%) survived to hospital discharge. CONCLUSIONS: The authors evaluated TOR guidelines in an independent, statewide OOHCA database. The results are consistent with the findings of the TOR investigation and suggest that this algorithm is a promising tool for TOR decision-making in the field.