Prospective comparison of emergency physician–performed venous ultrasound and CT venography for deep venous thrombosis

Background

Venous thromboembolic disease is a major cause of mortality and morbidity.

Objectives

The aim of this study is to compare emergency physician–performed ultrasound (EPPU) of the lower extremities with CT venography (CTV) in emergency department (ED) patients undergoing workup for pulmonary embolism (PE).

Methods

This was a prospective study performed at a busy academic ED. Adult patients (>18) undergoing workup for PE were eligible for the study; enrollment was based on a convenience sample, during hours worked by the investigators. Study patients underwent EPPU of the lower extremities followed by CT angiogram (CTA) of the chest and CTV of the lower extremities. Sensitivity and specificity of the ultrasound examination were calculated using CTV as the gold standard.

Results

A total of 61 patients were enrolled. Of 61 patients, 50 (82%; 95% confidence interval [CI], 72%-91%) had negative workups; 11 (18%; 95% CI, 8%-27%) were noted to have PE on CTA; 6 (10%; 95% CI, 2%-17%) were noted to have lower extremity deep venous thrombosis (DVT) on both EPPU and CTV evaluation; whereas 1 patient was found to have an external iliac DVT on CTV, which was not noted on EPPU. All patients with DVT (by either EPPU or CTV) were found to have PE on CTA. Sensitivity and specificity of EPPU when compared to CTV in the diagnosis of DVT was 86% (95% CI, 42%-99%) and 100% (95% CI, 91%-100%), respectively.

Conclusions

Emergency physician–performed ultrasound produces results consistent with CTV in the diagnosis of femoropopliteal DVT. More proximal clots are not evaluated with EPPU and thus may result in a false negative.     

Pulmonary Embolism Rule-out Criteria vs D-dimer testing in low-risk patients for pulmonary embolism: a retrospective study

Study objectives

The Pulmonary Embolism Rule-out Criteria (PERC) score has shown excellent negative predictive value; however, its use in the European population with high prevalence of PE is controversial. In Europe, PERC is not part of routine practice. For low-risk patients, guidelines recommend D-dimer testing, followed if positive by imaging study. We aimed to study the rate of diagnosis of PE after D-dimer testing in PERC-negative patients that could have been discharged if PERC was applied.

Method

This was a multicenter retrospective study in Paris, France. We included all patients with a suspicion of PE who had D-dimer testing in the emergency department, low pre-test probability, and a negative PERC score (that was retrospectively calculated). Patients with insufficient record to calculate PERC score were excluded. The primary end point was the rate of PE diagnosis before discharge in this population. Secondary end points included rate of invasive imaging studies and subsequent adverse events.

Results

We screened 4301 patients who had D-dimer testing, 1070 of whom were PERC negative and could be analyzed. The mean age was 35 years and 46% were men. D-dimer was positive (> 500 ng/L) in 167 (16%) of them; CTPA or V/Q scan was performed in 153 (14%) cases. PE was confirmed in 5 cases (total rate 0.5%, 95% confidence interval 0.1%-1.1%). Fifteen patients (1%) experienced non-severe adverse events.

Conclusion

D-dimer testing in PERC-negative patients led to a diagnosis of PE in 0.5% of them, with 15% of patients undergoing unnecessary irradiative imaging studies.     

Computed tomography angiography in patients with suspected pulmonary embolism-too often considered?

Background

Pulmonary embolism (PE) is a major cause of morbidity and mortality associated with surgery and medical illnesses. In recent years, pulmonary computed tomography angiography (CTA) has become the diagnostic method of choice. However, it remains unclear when to perform CTA and how often a decision based on clinical judgment results in positive or negative findings.

Methods

In a retrospective study, 261 patients admitted for suspected PE were evaluated with pulmonary CTA. Decisions to order CTA were based on clinical judgment and optionally quantitative d-dimer assays. Clinical, radiologic, and laboratory data were revisited and compared in patients with and without proven PE.

Results

The patients' mean age was 63 ± 1 years; almost 30% of all participants had at least a moderately reduced renal function. Pulmonary CTA demonstrated PE in only 14.9%; both age and sex distribution was comparable in the PE and non-PE group. Proximal deep vein thrombosis or pathologic chest x-rays were significantly more likely in patients with PE (P < .001 and P < .05), whereas echocardiography results were comparable. d-dimer values were noticeably higher in the PE group (P < .001); however, C-reactive protein and troponin T levels were not helpful.

Conclusions

Pulmonary CTA confirmed PE in only a minority of patients and may be overused. Clinical judgment in conjunction with d-dimer evaluation was of limited help to predict positive results but surprisingly comparable with previous results using pretest probability scoring systems. Using present and previous data, a simplified enhanced algorithm is proposed to reduce use of CTA.     

Assessment of the pulmonary embolism rule-out criteria rule for evaluation of suspected pulmonary embolism in the emergency department

Background

Overuse of resources when evaluating pulmonary embolism (PE) is a concern if the D-dimer assay is improperly used in the evaluation of emergency department patients with suspected PE. The pulmonary embolism rule-out criteria (PERC) rule was derived to prevent unnecessary diagnostic testing in this patient population. The objective of this study was to assess the PERC rule's performance in an external population.

Methods

This was a secondary analysis of a prospectively collected database comparing PERC rule variables to diagnosis of PE in consecutive patients with suspicion for PE. Bivariate analysis on individual variables and the overall accuracy of the PERC rule were performed.

Results

Patients on 120 randomly assigned shifts were enrolled with a PE prevalence of 12%. The sensitivity, specificity, positive predictive, and negative predictive values of the PERC rule were 100% (95% confidence interval [CI], 79%-100%), 16% (95% CI, 10%-24%), 14% (95% CI, 8%-14%), and 100% (95% CI, 80%-100%), respectively, for the total patient population, and 100% (95% CI, 25%-100%), 33% (95% CI, 12%-35%), 2% (95% CI, 0%-11%), and 100% (95% CI, 75%-100%), respectively, for the low pretest probability population. Bivariate analysis showed unilateral leg swelling, recent surgery, and a history of venous thromboembolic event to be predictive of the diagnosis of PE.

Conclusions

The PERC rule may identify a cohort of patients with suspected PE for whom diagnostic testing beyond history and physical examination is not indicated.     

Coronary artery disease progression in patients without significant stenosis on coronary computed tomographic angiography

Background

Patients who present to the emergency department (ED) with symptoms of potential acute coronary syndrome (ACS) can be safely discharged home after a coronary computed tomographic angiography (CTA) with a negative result. However, the duration of time for which a negative coronary CTA scan result can be used to inform decision making when patients have recurrent symptoms is not known.

Objective

We examined patients who received more than 1 coronary CTA for evaluation of ACS to determine whether they had disease progression. Our main outcome was whether any patient had a maximal stenosis cross the threshold from noncritical (<50% maximal stenosis) to potentially critical disease.

Methods

We performed a structured comprehensive record search of all coronary CTAs performed from 2005 to 2010 at a tertiary care health system. Low-to-intermediate risk ED patients who received 2 or more coronary CTAs, at least 1 from an ED evaluation for potential ACS, were identified. Patients who were revascularized between scans were excluded. We collected demographic data, clinical course, time between scans, and number of ED visits between scans. Record review was structured and done by trained abstractors. Our main outcome was progression of coronary stenosis between scans, specifically crossing the threshold from noncritical to potentially critical disease.

Results

Overall, 32 patients who received repeat imaging were identified (median age, 45 years; interquartile range, 37.5-48; 56% female; 88% black). The median time between studies was 27.3 months (interquartile range, 18.2-33.2). Twenty-two patients did not have stenosis in any vessel on either coronary CTA, 2 studies showed increasing stenosis of less than 20%, and the rest showed “improvement” due to better imaging quality. No patient initially below the 50% threshold subsequently exceeded it (0%; 95% confidence interval, 0-11.0%). No patient had acute myocardial infarction or revascularization either between scans or within a year after the repeated imaging.

Conclusion

Repeated imaging potentially may not be warranted within 2 years of a negative coronary CTA result. The low rate of progression from subcritical to critical disease is consistent with observations in patients who have had prior negative cardiac catheterizations.     

Emergency Department Variation in Utilization and Diagnostic Yield of Advanced Radiography in Diagnosis of Pulmonary Embolus

Background

There is growing pressure to measure and reduce unnecessary imaging in the emergency department.

Objective

We study provider and hospital variation in utilization and diagnostic yield for advanced radiography in diagnosis of pulmonary embolism (PE) and to assess patient- and provider-level factors associated with diagnostic yield.

Methods

Retrospective chart review of all adult patients presenting to four hospitals from January 2006 through December 2009 who had a computed tomography or ventilation/perfusion scan to evaluate for PE. Demographic data on the providers ordering the scans were collected. Diagnostic yield (positive scans/total scans ordered) was calculated at the hospital and provider level. The study was not designed to assess appropriateness of imaging.

Results

There was significant variation in utilization and diagnostic yield at the hospital level (chi-squared, p < 0.05). Diagnostic yield ranged from 4.2% to 8.2%; after adjusting for patient- and provider-level factors; the two hospitals with an emergency medicine residency training program had higher diagnostic yields (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.6–2.5 and OR 1.9, 95% CI 1.5–2.4). There was no significant variation in diagnostic yield among the 90 providers after adjusting for patient, hospital, and provider characteristics. Providers with < 10 years of experience had lower odds of diagnosing a PE than more experienced graduates (OR 0.8, 95% CI 0.6–0.9).

Conclusions

Although we found significant variation in utilization of advanced radiography for PE and diagnostic yield at the hospital level, there was no significant variation at the provider level after adjusting for patient-, hospital-, and provider-level factors.     

Risk tolerance for the exclusion of potentially life-threatening diseases in the ED

Objective

Given the same pretest probability (10%) for subarachnoid hemorrhage (SAH), pulmonary embolism (PE), and acute coronary syndrome (ACS), we determined if differences exist in the risk tolerance for disease exclusion according to published guidelines given a negative test result.

Methods

Published guidelines that make practice recommendations on the evaluation of ACS, PE, and SAH were sought using the National Guideline Clearinghouse in low-risk settings. Second-order Monte Carlo simulation was performed to determine point estimates and confidence intervals (CIs) for posttest probabilities assuming a pretest probability of 10%.

Results

Guidelines recommend that patients with low-risk suspected ACS should undergo stress testing. For SAH, computed tomography (CT) followed by lumbar puncture (LP) is recommended without mention of pretest probability; and D-dimer testing is recommended to exclude PE in low-risk patients. Test sensitivity for thallium-201 single photon emission computed tomography (SPECT) was 89%, exercise echocardiogram was 85%, D-dimer testing was 95%, and CT/LP for SAH was 100% (as a gold standard) and CT only was 97.5%. Given a negative test result, for PE, posttest probability was 0.5% (95% CI 0.1%-0.9%); for SPECT, 1.1% (SD 0.5%-1.6%); and for exercise echocardiogram, 1.5% (95% CI 0.5%-2.5%) compared with a posttest probability of 0% for CT followed by LP for SAH. Using a CT-only approach gives a posttest probability of 0.2% (95% CI 0.2%-0.4%).

Conclusions

Guidelines for suspected PE and ACS allow small but nonzero calculated risk end points in low-risk settings, whereas SAH guidelines afford no misses. Because many gold standard tests are more invasive and can have adverse effects, guideline authors should consider adopting a standard acceptable miss rate as an end point for workups with low clinical suspicion to avoid the overuse of invasive testing.     

Injuries occurring in hospital staff attending medical emergency team (MET) calls—A prospective,observational study

Background

Clinical emergency response systems such as medical emergency teams (MET) have been implemented in many hospitals worldwide, but the effect that these systems have on injuries to hospital staff is unknown. The objective of this study was to determine the rate and nature of injuries occurring in hospital staff attending MET calls.

Methods

This study was a prospective, observational study, using a structured interview, of 1265 MET call participants, in a 650 bed urban, teaching hospital. Data was collected on the number and the nature of injuries occurring in hospital staff attending MET calls.

Results

Over 131 days, 248 MET calls were made. An average of 8.1 staff participated in each MET call. The overall injury rate was 13 (95% confidence interval (CI) 7–20) per 1000 MET participant attendances, and 70 (95% CI 38–102) per 1000 MET calls. One injured participant required time off-work, an injury requiring time off-work rate of 1 (95% CI 0–4) per 1000 MET participant attendances, or 4 (95% CI 0–27) per 1000 MET calls. The relative risk of sustaining an injury if the MET participant performed chest compressions, contacted patient body fluids on clothing or protective equipment, without direct contact to skin or mucosa, or lifted the patient or a patient body part was 11.0 (95% CI 4.2–28.6), 8.7 (95% CI 3.4–22.0) and 5.5 (95% CI 2.1–14.2), respectively.

Conclusion

The rate of injuries occurring to hospital staff attending MET calls is relatively low, and many injuries could be considered relatively minor.     

Factors Associated With Home Discharge Among Veterans With Stroke

Objective

To determine which patient-, treatment-, and facility-level characteristics were associated with home discharge among patients hospitalized for stroke within the Department of Veterans Affairs.

Design

Retrospective observational study.

Setting

Veterans Affairs facilities nationwide.

Participants

Veterans hospitalized for stroke during fiscal year 2007 to fiscal year 2008 (N=12,565).

Intervention

Not applicable.

Main Outcome Measure

Discharge location after hospitalization.

Results

There were 10,130 (80.6%) veterans discharged home after hospitalization for acute stroke. Married veterans were more likely than nonmarried veterans to be discharged home (odds ratio [OR]=1.23; 95% confidence interval [CI]=1.11–1.35). Compared with veterans admitted to the hospital from home, patients admitted from extended care were less likely to be discharged home (OR=.04; 95% CI=.03–.07). Compared with those with occlusion of cerebral arteries, patients with intracerebral hemorrhage (OR=.61; 95% CI=.50–.74) or other central nervous system hemorrhage (OR=.78; 95% CI=.63–.96) were less likely to be discharged home, whereas patients with occlusion of precerebral arteries (OR=1.36; 95% CI=1.07–1.73) were more likely to return home. Evidence of congestive heart failure (OR=.85; 95% CI=.76–.95), fluid and electrolyte disorders (OR=.86; 95% CI=.77–.96), internal organ procedures and diagnostics (OR=.87; 95% CI=.78–.97), and serious nutritional compromise (OR=.49; 95% CI=.40–.62) during hospitalization remained independently associated with lower odds of home discharge. Longer hospitalizations and receipt of rehabilitation services while hospitalized acutely were negatively associated, whereas treatment on more bed sections and rehabilitation accreditation of the facility were positively associated with home discharge. Region exerted a statistically significant effect on home discharge.

Conclusions

We found sociological, clinical, and facility-level factors associated with home discharge after hospitalization for acute stroke. Findings document the importance of considering a broad range of characteristics rather than focusing only on a few specific traits during discharge planning.     

The effect of percutaneous coronary intervention in patients suffering from ST-segment elevation myocardial infarction complicated by out-of-hospital cardiac arrest on 30 days survival

Aim of the study

To question the beneficial effects of the recommended early percutaneous coronary intervention (PCI) after out-of-hospital cardiac arrest on 30-day survival with favourable neurological outcome.

Methods

Prospectively collected data of 1277 out of hospital cardiac arrest patients between 2005 and 2010 from a registry at a tertiary care university hospital were used for a cohort study.

Results

In 494 (39%) arrest patients ST-segment elevation was identified in 249 (19%). Within 12 h after restoration of spontaneous circulation catheter laboratory investigations were initiated in 197 (79%) and PCI in 183 (93%) (78% got PCI in less than180 min). Adjustment for a cumulative time without chest compressions <2 min, initial shockable rhythm, cardiac arrest witnessed by healthcare professionals, and a higher core temperature at time of hospitalization reduced the effect of PCI on favourable neurological outcome at 30 days (OR 1.40; 95% CI, 0.53–3.7) compared to the univariate analysis (OR 2.52; 95% CI, 1.42–4.48).

Conclusion

This cohort study failed to demonstrate the beneficial effects of PCI as part of post-resuscitation care on 30-day survival with a favourable neurological outcome.     

Risk Factors for Serious Underlying Pathology in Adult Emergency Department Nontraumatic Low Back Pain Patients

Background

Nontraumatic low back pain (LBP) is a common emergency department (ED) complaint and can be caused by serious pathologies that require immediate intervention or that lead to death.

Objective

The primary goal of this study is to identify risk factors associated with serious pathology in adult nontraumatic ED LBP patients.

Methods

We conducted a health records review and included patients aged ≥ 16 years with nontraumatic LBP presenting to an academic ED from November 2009 to January 2010. We excluded those with previously confirmed nephrolithiasis and typical renal colic presentation. We collected 56 predictor variables and outcomes within 30 days. Outcomes were determined by tracking computerized patient records and performance of univariate analysis and recursive partitioning.

Results

There were 329 patients included, with a mean age of 49.3 years; 50.8% were women. A total of 22 (6.7%) patients suffered outcomes, including one death, five compression fractures, four malignancies, four disc prolapses requiring surgery, two retroperitoneal bleeds, two osteomyelitis, and one each of epidural abscess, cauda equina, and leaking abdominal aortic aneurysm graft. Risk factors identified for outcomes were: anticoagulant use (odds ratio [OR] 15.6; 95% confidence interval [CI] 4.2–58.5), decreased sensation on physical examination (OR 6.9; CI 2.2–21.2), pain that is worse at night (OR 4.3; CI 0.9–20.1), and pain that persists despite appropriate treatment (OR 2.2; CI 0.8–5.6). These four predictors identified serious pathology with 91% sensitivity (95% CI 70–98%) and 55% specificity (95% CI 54–56%).

Conclusion

We successfully identified risk factors associated with serious pathology among ED LBP patients. Future prospective studies are required to derive a robust clinical decision rule.     

Does the Emergency Medical Treatment and Labor Act Affect Emergency Department Use?

Background

Emergency departments (EDs) face increasing patient volumes and economic pressures. These problems have been attributed to the Emergency Medical Treatment and Labor Act (EMTALA).

Study objective

To determine whether modifying EMTALA might reduce ED use.

Methods

We surveyed ED patients to assess their knowledge of hospitals’ obligations to treat all patients regardless of insurance and to determine whether knowledge is associated with ED use.

Results

Among 4136 study subjects, 72% reported awareness of the law. Sixty-one percent of subjects were moderate ED users (≥ 1 additional ED visit in 12 months). Moderate users more often knew the law (74% vs. 70%, p = 0.005). Multivariate regression showed that factors associated with moderate use were: awareness of EMTALA (odds ratio [OR] 1.44; 95% confidence interval [CI] 1.24–1.67), adult patient (OR 1.94; 95% CI 1.69–2.22), and government insurance (OR 2.67; 95% CI 2.30–3.08) or uninsured (OR 1.72; 95% CI 1.42–2.08). Only 8% of subjects were high-frequency users (≥5 visits). High-frequency users were more often aware of EMTALA (78% vs. 72%, p = 0.02). Covariates associated with high frequency were EMTALA awareness (OR 1.69; 95% CI 1.28–2.24), adult patient (OR 2.59; 95% CI 2.00–3.36), and government insurance (OR 3.73; 95% CI 2.76–5.06) or uninsured (OR 3.77; 95% CI 2.65–5.35).

Conclusion

Many patients know that the law requires hospitals to provide care. This knowledge is associated with more frequent ED use. EMTALA changes might reduce ED use, but broader policy implications should be considered.     

The Relationship between Patients' Perceptions of Team Effectiveness and their Care Experience in the Emergency Department

Background

Effective teamwork is important in the fast-paced Emergency Department (ED) setting. Most of the teamwork literature addresses the provider's perspective of teamwork rather than the patient's perspective.

Objective

Examine the relationship between patients' perceptions of teamwork and care experience in the ED.

Methods

We conducted a cross-sectional survey study of adult patients seen at the University of Pennsylvania ED during the fall of 2011. Patients rated overall satisfaction, pain management, trust, and confidence in the team and likelihood of treatment compliance (outcomes) and four components of team effectiveness (role clarity, shared goals, relationships, and job satisfaction) on a Likert scale. We examined the relationship between patients' perception of teamwork and the outcomes using multivariate analysis, controlling for sociodemographic factors.

Results

We collected 1010 surveys. Patients rated the individual components of teamwork equally, with about 70% rating teamwork as “Very High.” Most patients who rated teamwork highly also rated their confidence and trust in their providers highly (80–90%) compared to 20% of those who rated teamwork lower. The relative risk ratios between high and low teamwork were 4.1 (95% confidence interval [CI] 2.8–5.9) for overall satisfaction, 3.9 (95% CI 2.7–5.8) for satisfaction with pain treatment, 5.3 (95% CI 3.6–7.8) for confidence in providers, and 1.9 (95% CI 1.5–2.5) for likelihood to follow-up treatment recommendations.

Conclusions

Patient satisfaction and willingness to adhere to treatment recommendations are highly correlated with patients' perceptions of ED teamwork.     

Simultaneous T-wave inversions in anterior and inferior leads: an uncommon sign of pulmonary embolism

Background

Pulmonary embolism (PE), a major cause of morbidity and mortality, remains an elusive diagnosis. Recently investigators have found a new electrocardiographic (ECG) finding, simultaneous T-wave inversions in the anterior and inferior leads, which may distinguish PE from acute coronary syndrome (ACS).

Objectives

Our primary objective was to estimate the prevalence of this finding in PE. We also estimate the inter-rater reliability of this finding, its test characteristics, and assess ECG findings traditionally associated with PE.

Methods

In this unmatched case-control study, we selected electrocardiograms from patients diagnosed with PE, ACS, and non-cardiac chest pain. Two emergency physicians, blinded to diagnoses, reviewed electrocardiograms for explicitly defined ECG findings. We calculated kappa (K) for inter-rater agreement and estimated prevalence differences (PD) for findings in the PE group vs. pooled control groups.

Results

We included 97 patients with PE, 89 with ACS, and 105 with non-cardiac chest pain. A 1-mm T-wave inversion was seen in both III and V₁ in 11/97 (0.113) of patients with PE vs. 9/194 (0.046) controls (PD 0.07 [95% confidence interval (CI) −0.01–+0.14]; K = 0.7). Other criteria for anterior and inferior T-wave inversions were less common in PE (0.04–0.05). Among several other ECG abnormalities tested, only sinus tachycardia (PD 0.20 [95% CI 0.09–0.31]; K = 0.7) and the classic S_IQ_IIIT_III pattern (PD 0.05 [95% CI −0.01–+0.11]; K = 0.5) statistically distinguished PE and were noted with fair or better inter-rater agreement.

Conclusion

In our study, simultaneous T-wave inversions in anterior and inferior leads were associated with PE but are seen in only 4–11% of cases.     

Chest compression depth and survival in out-of-hospital cardiac arrest

Aim

Outcomes from out-of-hospital cardiac arrest (OHCA) may improve if rescuers perform chest compressions (CCs) deeper than the previous recommendation of 38–51 mm and consistent with the 2010 AHA Guideline recommendation of at least 51 mm. The aim of this study was to assess the relationship between CC depth and OHCA survival.

Methods

Prospective analysis of CC depth and outcomes in consecutive adult OHCA of presumed cardiac etiology from two EMS agencies participating in comprehensive CPR quality improvement initiatives. Analysis: Multivariable logistic regression to calculate adjusted odds ratios (aORs) for survival to hospital discharge and favorable functional outcome.

Results

Among 593 OHCAs, 136 patients (22.9%) achieved return of spontaneous circulation, 63 patients (10.6%) survived and 50 had favorable functional outcome (8.4%). Mean CC depth was 49.8 ± 11.0 mm and mean CC rate was 113.9 ± 18.1 CC min⁻¹. Mean depth was significantly deeper in survivors (53.6 mm, 95% CI: 50.5–56.7) than non-survivors (48.8 mm, 95% CI: 47.6–50.0). Each 5 mm increase in mean CC depth significantly increased the odds of survival and survival with favorable functional outcome: aORs were 1.29 (95% CI 1.00–1.65) and 1.30 (95% CI 1.00–1.70) respectively.

Conclusion

Deeper chest compressions were associated with improved survival and functional outcome following OHCA. Our results suggest that adhering to the 2010 AHA Guideline-recommended depth of at least 51 mm could improve outcomes for victims of OHCA.     

Derivation of a Clinical Decision Guide in the Diagnosis of Cervical Facet Joint Pain

Objective

To derive a clinical decision guide (CDG) to identify patients best suited for cervical diagnostic facet joint blocks.

Design

Prospective cohort study.

Setting

Pain management center.

Participants

Consecutive patients with neck pain (N=125) referred to an interventional pain management center were approached to participate.

Interventions

Subjects underwent a standardized testing protocol, performed by a physiotherapist, prior to receiving diagnostic facet joint blocks. All subjects received the reference standard diagnostic facet joint block protocol, namely controlled medial branch blocks (MBBs). The physicians performing the MBBs were blinded to the local anesthetic used and findings of the clinical tests.

Main Outcome Measures

Multivariate regression analyses were performed in the derivation of the CDGs. Sensitivity, specificity, positive and negative likelihood ratios, and 95% confidence intervals (CIs) were calculated for the index tests and CDGs.

Results

A CDG involving the findings of the manual spinal examination (MSE), palpation for segmental tenderness (PST), and extension-rotation (ER) test demonstrated a specificity of 84% (95% CI, 77–90) and a positive likelihood ratio of 4.94 (95% CI, 2.8–8.2). Sensitivity of the PST and MSE were 94% (95% CI, 90–98) and 92% (95% CI, 88–97), respectively. Negative findings on the PST were associated with a negative likelihood ratio of .08 (95% CI, .03–.24).

Conclusions

MSE, PST, and ER may be useful tests in identifying patients suitable for diagnostic facet joint blocks. Further research is needed to validate the CDGs prior to their routine use in clinical practice.     

Predicting Bloodstream Infection via Systemic Inflammatory Response Syndrome or Biochemistry

Background

The yield of blood cultures is approximately 10%. This could be caused by inaccurate prediction of patients with bloodstream infection (BSI).

Objectives

To evaluate the usability of systemic inflammatory response syndrome (SIRS) or biochemical analyses as predictors for positive blood culture.

Methods

We conducted a prospective cohort study at a Danish regional hospital from February 1 to April 30, 2010. All adult patients were included on the first time blood cultures were sampled during admission. Data were obtained from medical records, databases on microbiology, biochemistry, and antibiotic treatment. Data included time of admission, date and result of blood culture, results of biochemical analyses, and clinical measurements on the day of blood culture. Prediction of BSI was analyzed according to both individual parameters and parameters combined in different sepsis score groups. Associations were calculated using multiple logistic regression.

Results

Patients with BSI (68 patients) were compared to patients without BSI (828 patients). Respiratory rate, body temperature, and C-reactive protein were strongest associated with BSI, with adjusted odds ratio (OR) 5.42, 95% confidence interval (CI) 1.13–25.9; OR 2.55, 95% CI 1.34–4.87; and OR 6.06, 95% CI 0.82–44.6, respectively. SIRS was associated with BSI, with crude OR 7.25, 95% CI 1.75–30.1. Neutrophil count and p-carbamide were not associated with BSI: adjusted OR 0.88, 95% CI 0.36–2.13 and OR 1.44, 95% CI 0.82–2.52, respectively. Only one of the sepsis score groups was associated with BSI: crude OR 2.13, 95% CI 1.08–4.19.

Conclusions

SIRS is an adequate predictor of BSI. By contrast, biochemical parameters were not useful as predictors of BSI.     

Cervical Spine Injury: Analysis and Comparison of Patients by Mode of Transportation

Background

Cervical spine injury (CSI) studies have identified different factors contributing to CSI, but none compares the incidence and pattern of injury of patients arriving at the Emergency Department (ED) by private vehicle (PV).

Objective

We compared the characteristics and injury patterns in CSI patients who were transported to the ED via Emergency Medical Services (EMS) versus PV.

Methods

We conducted a three-hospital retrospective review of patients with CSI from January 1, 2000 to December 31, 2007. We excluded transfers and follow-up visits. Using a standardized data collection form, we reviewed demographics, mode of transport, mechanism of injury, imaging results, injury type and level, and neurologic deficits. Means and proportions were compared using t-tests and chi-squared as appropriate.

Results

Of 1174 charts identified, 718 met all study criteria; 671 arrived by EMS and 47 by PV. There was no difference between groups in age or gender. Ground-level fall was more likely in PV patients (32%, 95% confidence interval [CI] 20–46% vs. 6%, 95% CI 4–9%), whereas motor vehicle collision was less likely (32%, 95% CI 20–46% vs. 67%, 95% CI 63–70%). PV patients more often sustained a stable injury (66%, 95% CI 52–78% vs. 40%, 95% CI 36–44%), and were more often triaged to a lower-acuity area (25%, 95% CI 15–40% vs. 4%, 95% CI 3–6%). The incidence of neurologic deficit was similar (32%, 95% CI 20–46% vs. 24%, 95% CI 21–28%), though more PV patients had spinal cord injury without radiographic abnormality (21%, 95% CI 12–35% vs. 5%, 95% CI 4–7%).

Conclusion

A small proportion of patients with CSI present to the ED by PV. Although most had stable injuries, a surprising number had unstable injuries with neurologic deficits, and were triaged to lower-acuity areas in the ED.     

Risk of venous thromboembolism in patients with borderline quantitative D-dimer levels

Objective

The lower threshold for D-dimer in evaluating patients with low clinical risk of venous thromboembolism (VTE) ranges from 200 to 500 ng/mL. We compared the rates of VTE in patients based on D-dimer values. We hypothesized that the rate of VTE in low-risk patients with D-dimer levels less than 500 would be less than 1%.

Methods

Study Design: This was a retrospective chart review: Setting: The study was performed in a academic, suburban emergency department (ED). Subjects: Emergency department patients with suspected VTE and D-dimer obtained were included in the study. D-dimer assay: The D-dimer assay is a quantitative instrumentation latex suspension of plasma specimens. Outcomes: Presence of VTE within 30 days of ED visit. Data Analysis: Assuming a 0% event rate in patients with D-dimer levels between 200 and 500 ng/mL, a sample of 450 patients would result in a 95% confidence interval upper limit of 0.6%.

Results

There were 1270 ED patients with suspected VTE in which D-dimer levels were performed between October 2005 and October 2006. Patient mean age was 47.8 ± 19.3 years; 63.2% were female, 78.2% were white. Of all D-dimer levels, 497 (39.1%) were less than 200 ng/mL, 479 (37.7%) were between 200 and 500 μg/mL, and 294 (23.1%) were greater than 500 ng/mL. There were no VTE events diagnosed in any of the patients with D-dimer levels less than 200 ng/mL. Four patients with D-dimer levels between 200 and 500 μg/mL had a pulmonary embolism on computed tomography angiography. Of these 4 patients, 3 had moderate clinical risk based on Well's criteria and one had a false-positive computed tomography. There were no cases of VTE in the remaining 475 patients (0%; 95% confidence interval 0%-0.6%).

Conclusion

The rate of confirmed VTE in low-risk patients with D-dimer levels between 200 and 500 ng/mL is very low. Low-risk patients with suspected VTE with D-dimer levels less than 500 ng/mL might not require additional testing.     

A Survey of the Prevalence of Cell Phones Capable of Receiving Health Information among Patients Presenting to an Urban Emergency Department

Background

Mobile devices have been shown to assist patients with comprehension of health information, yet sparse data exist on what mobile devices patients own and preferences for receiving health information.

Objectives

To determine the prevalence of mobile devices capable of receiving health information among patients/visitors presenting to an urban Emergency Department (ED).

Methods

A random sample of patients/visitors ≥18 years was surveyed. The primary outcome was prevalence of mobile devices capable of receiving health information among patient/visitor units presenting to the ED. Means and 95% confidence intervals were derived for continuous data; proportions with Fisher’s exact 95% confidence intervals were derived for categorical data. Institutional review board approval was received before study initiation.

Results

Surveyors approached 1307 subjects: 68% (885) were eligible; 70% (620) agreed to participate; 4 participants were excluded, leaving 70% (616) in the final sample. Of the 616 participants, 82% stated cell phone ownership (95% confidence interval [CI] 0.79–0.85). Among cell phone owners (n = 507), 90% had the device with them (95% CI 0.87–0.92) in the ED. Of these participants (n = 456), 77% had text messaging (95% CI 0.73–0.81), 51% had Internet (95% CI 0.47–0.56), 51% had e-mail (95% CI 0.46–0.56), 39% could download audio content (95% CI 0.34–0.43), and 35% could download videos (95% CI 0.31–0.40). Even among those having an annual income ≤$20,000, nearly 80% of persons owned cell phones.

Conclusions

Cell phones capable of receiving health information are prevalent among patients/visitors presenting to an urban ED.