Lower-extremity Doppler for deep venous thrombosis--can emergency physicians be accurate and fast?

Initial accuracy of bedside ultrasound performed by emergency physicians for multiple indications after a short training period

PURPOSES

Emergency physician-performed ultrasonography holds promise as a rapid and accurate method to diagnose multiple diseases in the emergency department (ED). Our objective was to assess the initial diagnostic accuracy (first 55 explorations) of emergency physician-performed ultrasonography for multiple categories of ultrasound use after a short training period.

BASIC PROCEDURES

This was a prospective observational study conducted at an urban ED from June 2010 to March 2011 in patients with suspected cholecystitis, hydronephrosis, deep vein thrombosis, and different cardiovascular problems. Five physicians had a 10-hour training session before enrolling patients. The test characteristics of bedside ultrasonography were determined with the final radiologist/cardiologist interpretation.

MAIN FINDINGS

A total of 275 ultrasonographic examinations were performed (78 abdominal explorations, 80 renal explorations, 76 2-point compression ultrasonographic examinations in patients with suspected deep vein thrombosis, and 41 echocardiograms in patients with different acute cardiovascular problems). Radiologists/cardiologists detected 28 cases of cholecystitis, 26 cases of deep vein thrombosis, 49 cases of hydronephrosis, and 15 cases of significant cardiovascular alterations. The overall diagnostic accuracy of ED ultrasonograms yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 92.6% (95% confidence interval [CI], 90%-99%), 89% (95% CI, 84%-94%), 86.2 % (95% CI, 82%-93%), and 94.2% (95% CI, 92%-99%), respectively. Nineteen (6.9%) false-positive results and 6 false-negative results (2.1%) were obtained.

PRINCIPAL CONCLUSIONS

Emergency physicians in our institution attained reasonably high initial accuracy in the performance of ultrasonography for a variety of clinical problems after a 10-hour training period.

An overview of emergency ultrasound in the United States

BACKGROUND

As emergency ultrasound use explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field.

METHODS

Approaches to education, scanning, documentation, and organization are also described.

RESULTS

Machines have reduced in price and once purchased further material costs are low. Staffing costs in terms of training, etc have yet to be assessed, but indications from elsewhere are that these are low. Length of stay in the emergency department dramatically decreases, thus increasing patient satisfaction while maintaining an even higher standard of care.

CONCLUSION

Emergency screening ultrasound is now a nationally accepted tool for the rapid assessment of the emergency patient.

Review article: Use of ultrasound in the developing world

As portability and durability improve, bedside, clinician-performed ultrasound is seeing increasing use in rural, underdeveloped parts of the world. Physicians, nurses and medical officers have demonstrated the ability to perform and interpret a large variety of ultrasound exams, and a growing body of literature supports the use of point-of-care ultrasound in developing nations. We review, by region, the existing literature in support of ultrasound use in the developing world and training guidelines currently in use, and highlight indications for emergency ultrasound in the developing world. We suggest future directions for bedside ultrasound use and research to improve diagnostic capacity and patient care in the most remote areas of the globe.

The efficacy and value of emergency medicine: a supportive literature review

Study objectives

The goal of this study was to identify publications in the medical literature that support the efficacy or value of Emergency Medicine (EM) as a medical specialty and of clinical care delivered by trained emergency physicians. In this study we use the term "value" to refer both to the "efficacy of clinical care" in terms of achieving desired patient outcomes, as well as "efficiency" in terms of effective and/or cost-effective utilization of healthcare resources in delivering emergency care. A comprehensive listing of publications describing the efficacy or value of EM has not been previously published. It is anticipated that the accumulated reference list generated by this study will serve to help promote awareness of the value of EM as a medical specialty, and acceptance and development of the specialty of EM in countries where EM is new or not yet fully established.

Methods

The January 1995 to October 2010 issues of selected journals, including the EM journals with the highest article impact factors, were reviewed to identify articles of studies or commentaries that evaluated efficacy, effectiveness, and/or value related to EM as a specialty or to clinical care delivered by EM practitioners. Articles were included if they found a positive or beneficial effect of EM or of EM physician-provided medical care. Additional articles that had been published prior to 1995 or in other non-EM journals already known to the authors were also included.

Results

A total of 282 articles were identified, and each was categorized into one of the following topics: efficacy of EM for critical care and procedures (31 articles), efficacy of EM for efficiency or cost of care (30 articles), efficacy of EM for public health or preventive medicine (34 articles), efficacy of EM for radiology (11 articles), efficacy of EM for trauma or airway management (27 articles), efficacy of EM for using ultrasound (56 articles), efficacy of EM faculty (34 articles), efficacy of EM residencies (24 articles), and overviews and editorials of EM efficacy and value (35 articles).

Conclusion

There is extensive medical literature that supports the efficacy and value for both EM as a medical specialty and for emergency patient care delivered by trained EM physicians.

How long does it take to perform emergency ultrasound for the primary indications?

Purpose

Although emergency ultrasound (EU) is gaining popularity, EU is performed in a minority of emergency departments (EDs). The perception may exist that EU is too time-consuming. This study sought to determine the duration of EUs performed for the primary indications by staff emergency physicians (EPs).

Methods

A prospective, time–motion study was conducted on a convenience sample of EUs at the Sudbury Regional Hospital ED from June to August 2006. All EPs had Canadian EU certification. A research assistant timed EUs. Primary EU indications in Canada are: cardiac arrest evaluation, rule-out pericardial effusion, rule-out intraperitoneal free fluid in trauma, rule-out abdominal aortic aneurysm, and rule-in intrauterine pregnancy. Descriptive statistics are reported.

Results

Eleven EPs performed 66 EUs for the primary indications on 51 patients. The mean EU duration was 137.8 s (range 11–465; CI 123.0–162.6). There was no difference in the duration of EUs performed by the two most experienced EPs (n = 37; duration = 129.4; CI = 96.4–162.4) compared to the other EPs (n = 29; duration = 148.4; CI = 110.6–186.2). Although subgroups were small, positive (n = 8; duration = 199.4; CI = 97.4–301.4), negative (n = 49; duration = 123.3; CI = 97.9–148.7), and indeterminate (n = 9; duration = 161.6; CI = 91.5–231.7) EUs did not differ in duration. There is some suggestion of differences in duration between types of EU, although again the subgroups were small: cardiac (n = 21; duration = 90.3; CI = 62.6–118.0), abdominal (n = 22; duration = 157.1; CI = 111.9–202.3), aneurysm (n = 15; duration = 170.1; CI = 117.5–222.7), transabdominal pelvic (n = 5; duration = 89.8; CI = 40.3–139.1), transvaginal (n = 3; duration = 246.0; CI = 30.6–461.4).

Conclusion

When performed by staff EPs with EU certification, mean EU duration for the primary indications was brief regardless of EP’s experience, EU type, or results.

Non-compressibility ratio of sonography in deep venous thrombosis

BACKGROUND

The risk of post-thrombotic syndrome and pulmonary embolism can be increased if there is failure to diagnose deep venous thrombosis (DVT) promptly. Emergency physicians (EPs) need a quick and readily available test to diagnose, treat and help them decide whether to discharge or admit DVT patients in a timely manner. The aim of this study was to investigate the value of the non-compressibility ratio of thrombosed veins in DVT patients, and give EPs an objective value to aid them in their decision-making with regard to DVT patients in the emergency department.

METHODS

We reviewed 34 adult patients with DVT diagnosed by sonography in an emergency department. Medical records including demographic data and sonography results were retrospectively reviewed and analyzed.

RESULTS

Mean age was 72.9 ± 16.5 years. Group I comprised 14 patients (41.2%) who had DVT in the popliteal and femoral veins. Group II comprised 8 patients (23.5%) who had DVT isolated to the popliteal vein and 12 patients (35.3%) who had DVT isolated to the femoral vein. Group I had a significantly higher non-compressibility ratio than Group II (93.4 ± 6.2% vs. 80.1 ± 19.2%, p < 0.05). The area under the receiver operating characteristic curve of the non-compressibility ratio between discriminating groups was 0.711 (95% confidence interval, 0.527-0.854; p < 0.05). The clinical prognostic score of Group I was significantly higher than that of Group II (6.2 ± 1.8 vs. 4.1 ± 2.6, p < 0.05). There was a significant positive correlation between the non-compressibility ratio of the thrombosed vein and the clinical prognostic score (p = 0.001).

CONCLUSION

The non-compressibility ratio of the thrombosed vein provides EPs with an objective test to evaluate the severity of DVT and to admit patients for consideration of adverse outcomes.

Accuracy of ultrasonography performed by critical care physicians for the diagnosis of DVT

BACKGROUND

DVT is common among critically ill patients. A rapid and accurate diagnosis is essential for patient care. We assessed the accuracy and timeliness of intensivist-performed compression ultrasonography studies (IP-CUS) for proximal lower extremity DVT (PLEDVT) by comparing results with the formal vascular study (FVS) performed by ultrasonography technicians and interpreted by radiologists.

METHODS

We conducted a multicenter, retrospective review of IP-CUS examinations performed in an ICU by pulmonary and critical care fellows and attending physicians. Patients suspected of having DVT underwent IP-CUS, using a standard two-dimensional compression ultrasonography protocol for the diagnosis of PLEDVT. The IP-CUS data were collected prospectively as part of a quality-improvement initiative. The IP-CUS interpretation was recorded and timed at the end of the examination on a standardized report form. An FVS was then ordered, and the FVS result was used as the criterion standard for calculating sensitivity and specificity. Time delays between the IP-CUS and FVS were recorded.

RESULTS

A total of 128 IP-CUS were compared with an FVS. Eighty-one percent of the IP-CUS were performed by fellows with <2 years of clinical ultrasonography experience. Prevalence of DVT was 20%. IP-CUS studies yielded a sensitivity of 86% and a specificity of 96% with a diagnostic accuracy of 95%. Median time delay between the ordering of FVS and the FVS result was 13.8 h.

CONCLUSIONS

Rapid and accurate diagnosis of proximal lower extremity DVT can be achieved by intensivists performing compression ultrasonography at the bedside.

Portable ultrasound for remote environments, part II: current indications

BACKGROUND

With recent advances in ultrasound technology, it is now possible to deploy lightweight portable imaging devices in the field. Techniques and studies initially developed for hospital use have been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in austere or prehospital environments.

OBJECTIVES

This review summarizes current ultrasound applications used in out-of-hospital arenas and highlights existing evidence for such use. The diversity of applications and environments is organized by indication to better inform equipment selection as well as future directions for research and development.

DISCUSSION

Trauma evaluation, casualty triage, and assessment for pneumothorax, acute mountain sickness, and other applications have been studied by field medical teams. A wide range of outcomes have been reported, from alterations in patient care to determinations of accuracy compared to clinical judgment or other diagnostic modalities.

CONCLUSIONS

The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although some studies of diagnostic accuracy exist in this setting, further research focused on clinically relevant outcomes data is needed.

The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll

The RUSH exam (Rapid Ultrasound in SHock examination), presented in this article, represents a comprehensive algorithm for the integration of bedside ultrasound into the care of the patient in shock. By focusing on a stepwise evaluation of the shock patient defined here as "Pump, Tank, and Pipes," clinicians will gain crucial anatomic and physiologic data to better care for these patients.

Resident training in emergency ultrasound: consensus recommendations from the 2008 Council of Emergency Medicine Residency Directors Conference

Over the past 25 years, research performed by emergency physicians (EPs) demonstrates that bedside ultrasound (US) can improve the care of emergency department (ED) patients. At the request of the Council of Emergency Medicine Residency Directors (CORD), leaders in the field of emergency medicine (EM) US met to delineate in consensus fashion the model "US curriculum" for EM residency training programs. The goal of this article is to provide a framework for providing US education to EM residents. These guidelines should serve as a foundation for the growth of resident education in EM US. The intent of these guidelines is to provide minimum education standards for all EM residency programs to refer to when establishing an EUS training program. The document focuses on US curriculum, US education, and competency assessment. The use of US in the management of critically ill patients will improve patient care and thus should be viewed as a required skill set for all future graduating EM residents. The authors consider EUS skills critical to the development of an emergency physician, and a minimum skill set should be mandatory for all graduating EM residents. The US education provided to EM residents should be structured to allow residents to incorporate US into daily clinical practice. Image acquisition and interpretation alone are insufficient. The ability to integrate findings with patient care and apply them in a busy clinical environment should be stressed.

Financial impact of emergency department ultrasound

OBJECTIVES

There is limited information on the financial implications of an emergency department ultrasound (ED US) program. The authors sought to perform a fiscal analysis of an integrated ED US program.

METHODS

A retrospective review of billing data was performed for fiscal year (FY) 2007 for an urban academic ED with an ED US program. The ED had an annual census of 80,000 visits and 1,101 ED trauma activations. The ED is a core teaching site for a 4-year emergency medicine (EM) residency, has 35 faculty members, and has 24-hour availability of all radiology services including formal US. ED US is utilized as part of evaluation of all trauma activations and for ED procedures. As actual billing charges and reimbursement rates are institution-specific and proprietary information, relative value units (RVUs) and reimbursement based on the Centers for Medicare & Medicaid Services (CMS) 2007 fee schedule (adjusted for fixed diagnosis-related group [DRG] payments and bad debt) was used to determine revenue generated from ED US. To estimate potential volume, assumptions were made on improvement in documentation rate for diagnostic scans (current documentation rates based on billed volume versus diagnostic studies in diagnostic image database), with no improvements assumed for procedural ED US. Expenses consist of three components-capital costs, training costs, and ongoing operational costs-and were determined by institutional experience. Training costs were considered sunken expenses by this institution and were thus not included in the original return on investment (ROI) calculation, although for this article a second ROI calculation was done with training cost estimates included. For the purposes of analysis, certain key assumptions were made. We utilized a collection rate of 45% and hospitalization rates (used to adjust for fixed DRG payments) of 33% for all diagnostic scans, 100% for vascular access, and 10% for needle placement. An optimal documentation rate of 95% was used to estimate potential revenue.

RESULTS

In FY 2007, 486 limited echo exams of abdomen (current procedural terminology [CPT] 76705) and 480 limited echo cardiac exams were performed (CPT 93308) while there were 78 exams for US-guided vascular access (CPT 76937) and 36 US-guided needle placements when performing paracentesis, thoracentesis, or location of abscess for drainage (CPT 76492). Applying the 2007 CMS fee schedule and above assumptions, the revenue generated was 578 RVUs and $35,541 ($12,934 in professional physician fees and $22,607 in facility fees). Assuming optimal documentation rates for diagnostic ED US scans, ED US could have generated 1,487 RVUs and $94,593 ($33,953 in professional physician fees and $60,640 in facility fees). Program expenses include an initial capital expense (estimated at $120,000 for two US machines) and ongoing operational costs ($68,640 per year to cover image quality assurance review, continuing education, and program maintenance). Based on current revenue, there would be an annual operating loss, and thus an ROI cannot be calculated. However, if potential revenue is achieved, the annual operating income will be $22,846 per year with an ROI of 4.9 years to break even with initial investment.

CONCLUSIONS

Determining an ROI is a required procedure for any business plan for establishing an ED US program. Our analysis demonstrates that an ED US program that captures charges for trauma and procedural US and achieves the potential billing volume breaks even in less than 5 years, at which point it would generate a positive margin.

Venothromboembolism

This article focuses on the clinical presentation, diagnosis, and management of veno-thromboembolism, including deep venous thrombosis (DVT) and pulmonary embolism (PE), from the perspective of the emergency physician. The discussion is divided into two sections: DVT and PE. Because veno-thromboembolism is a continuum, certain aspects, such as background, incidence, the use of D dimer, and anticoagulation of both DVT and PE, are discussed together. Heavier emphasis is placed on topics germane to the emergency physician, and considerations for special populations are reviewed.

Systematic review of emergency physician-performed ultrasonography for lower-extremity deep vein thrombosis

OBJECTIVES

The authors performed a systematic review to evaluate published literature on diagnostic performance of emergency physician-performed ultrasonography (EPPU) for the diagnosis and exclusion of deep venous thrombosis (DVT).

METHODS

Structured search criteria were used to query MEDLINE and EMBASE, followed by a hand search of published bibliographies. Relevance and inclusion criteria required prospective investigation of emergency department (ED) outpatients with suspected DVT; diagnostic evaluations had to consist of EPPU followed by criterion standard (radiology-performed) imaging. Two authors independently extracted data from included studies; study quality was assessed utilizing a validated tool for quality assessment of diagnostic accuracy studies (QUADAS). Pooled data were analyzed using an unweighted summary receiver-operating-characteristic (SROC) curve; sensitivity and specificity were estimated using a random effects model.

RESULTS

The initial search yielded 1,162 publications. Relevance screening and selection yielded six articles including 936 patients. Four of the six studies reported adequate blinding but a number of other methodologic flaws were identified. A random effects model yielded an overall sensitivity of 0.95 (95% confidence interval [CI] = 0.87 to 0.99) and specificity of 0.96 (95% CI = 0.87 to 0.99).

CONCLUSIONS

Systematic review of six studies suggests that EPPU may be accurate for the diagnosis of DVT compared with radiology-performed ultrasound (US). However, given the methodologic limitations identified among the primary studies, the estimates of diagnostic test performance may be overly optimistic. Further research into EPPU for suspected DVT is needed before it can be adopted into routine clinical practice.

Ultrasound in the detection of venous thromboembolism

Venous thrombosis is a common disease process leading to tens of thousands of deaths per year. Despite prophylactic efforts, venous thromboembolic disease is a common and serious complication in critical care patients. Difficulty and delay in obtaining diagnostic imaging studies to rule out deep venous thrombosis is exacerbated by increased susceptibility that critically ill patients have to thromboembolism. Lower extremity venous ultrasound use by clinicians has been well studied and has proven both reliable and efficient. Evaluation of the upper extremities can be more challenging and requires a higher degree of technical skill. However, both can be integrated into an overall scheme of prevention, screening, and rapid diagnosis of thromboembolic disease and its complications. This article delves into available literature and describes performance of both applications in a critical care setting.

History of emergency and critical care ultrasound: The evolution of a new imaging paradigm

The tradition of clinical ultrasound in the hands of physicians who provide critical care to the most acutely ill patients stretches back into the 1980s and is rich with experiences from surgical, emergency medicine, and other practices. Now, as critical care ultrasound explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field. The development and battles for the right to use ultrasound at the patient's bedside for >20 yrs is described in relation to its emergency medicine and surgical origins. Approaches to education, scanning, documentation, and organization at the national and regional levels are described.

Duplex ultrasound in the emergency department for the diagnostic management of clinically suspected deep vein thrombosis

OBJECTIVES

To evaluate the accuracy and safety of an emergency duplex ultrasound (EDUS) evaluation performed by emergency physicians in the emergency department.

METHODS

Consecutive adult patients suspected of having their first episode of deep vein thrombosis (DVT) presenting to the emergency department were included in the study. All examinations were performed by emergency physicians trained with a 30-hour ultrasound course. Based on EDUS findings, patients were classified into one of three groups: normal, abnormal, and uncertain. Patients with abnormal and uncertain findings were initially treated as having a DVT. Patients with normal EDUS findings were discharged from the emergency department without anticoagulant therapy. A formal duplex ultrasound evaluation was repeated by a radiologist in all patients within 24-48 hours. Patients with normal findings on duplex ultrasound evaluation were followed up for symptomatic venous thromboembolism for up to one month.

RESULTS

A total of 399 patients were studied. The EDUS findings were normal in 301 (75%), abnormal in 90 (23%), and uncertain in eight (2%). All abnormal test results were confirmed by the formal duplex ultrasound evaluation, and three patients (0.8%) with uncertain findings on EDUS examination were subsequently diagnosed as having a distal DVT (positive predictive value, 95% [95% confidence interval, 92% to 95%]; negative predictive value, 100% [95% confidence interval = 99% to 100%]). No patients with normal findings on EDUS examination died or experienced venous thromboembolism at the one-month follow-up.

CONCLUSIONS

EDUS examination yielded a high negative predictive value and good positive predictive value, allowing rapid discharge and avoiding improper anticoagulant treatment.

[Validation of an emergency care physician training program "two-point flash US"]

BACKGROUND

The development of a short training program for emergency care physicians for rapid ultrasound assessment of two points (the groin and popliteal areas) could be useful for later implementation of a safe home care strategy for patients with suspected deep vein thrombosis before the results of a complete duplex-Doppler exploration are available.

PURPOSE

Validation of the proposed training program by studying inter-operator agreement (trainee versus vascular physician) in a multicentric assessment of 60 emergency care physicians. Establish the learning curve.

METHODOLOGY

Theoretical training: two-page document with schematic drawings and consultation of image bank on the Web. Practical training: 25 patients in all, the last 15 as an independent operator, writing a standardized report. Interoperator agreement: (a) centralized data collection and independent analysis of the report written by the trainee and a vascular physician for the same patients (n(o) 11 to 25); (b) determination of the coefficient of variance, kappa, and construction of the learning curve (900 agreement points for 60 trainees).

INCLUSION CRITERIA

(a) Treated distal or proximal thrombosis recruited by the vascular physician (blinded to the result of the flash US); patient's oral consent.

EXPECTED RESULTS

Learning curve leveling off at about the 20th patient with a kappa>0.61 or even 0.80. ORIGINAL CONTRIBUTION OF THE PROJECT: (a) Prospective, multicentric, blinded study: (i) confirming the feasibility of a two-point venous ultrasound performed by emergency care physicians; (ii) validation of the contents and duration of a short simplified training program; (b) Validation of a decision criterion for home care; If validated, this type of training program might be applied in other disciplines (intensive care, geriatrics).

Can emergency medicine residents detect acute deep venous thrombosis with a limited, two-site ultrasound examination?

The purpose of this prospective clinical study was to determine the ability of Emergency Medicine (EM) residents to accurately detect acute deep venous thrombosis (aDVT) after training in a limited, two-site examination. Six residents received a 90-min session consisting of a lecture and a hands-on component. Each resident then performed the examination on symptomatic extremities referred to the vascular laboratory of a community teaching hospital. The examination was limited to the femoral and popliteal sites and was considered normal when the vein completely compressed. A formal examination was completed by the vascular technician (who was blinded to the resident's results) within 30 min of the resident examination. Of the 121 symptomatic extremities, vascular technicians detected nine cases of aDVT in the target area (7% prevalence); resident examinations revealed eight of these (sensitivity 89%). EM residents can perform a limited duplex examination with considerable but not perfect accuracy after receiving very limited instruction.

Patient follow-up after negative lower extremity bedside ultrasound for deep venous thrombosis in the ED

OBJECTIVES

To evaluate the rate of patient compliance with follow-up ultrasound (US) examinations 5 to 7 days after emergency physician EP performed US exams to rule out lower extremity deep venous thrombosis (DVT) in the ED.

METHODS

This was a prospective observational study at a level I ED with a residency program, US training program, and an annual census of 75000. Hospital-based emergency US credentialing is available and derived from American College of Emergency Physicians guidelines. Five US-credentialed emergency physicians participated in the study. All patients who received negative lower extremity DVT US exams were eligible. All higher risk patients were given verbal and written instructions and provided with prescriptions to have a follow-up US examination 5 to 7 days after their examination in the ED. Those classified as "low risk" based on Wells criteria were excluded. After 3 months, patients were contacted via telephone and asked questions regarding their follow-up US examinations, reasons for not following up, continued symptoms, and thromboembolic events. Statistical methods included descriptive statistics.

RESULTS

One hundred fifty-nine patients were eligible for enrollment during the 10-month study period. Eighty-five patients (54%) fell into the higher risk category of these; 54 (64%) were contacted successfully. Fifteen (28%) of the patients contacted had obtained a follow-up US exam. Of the 39 who did not follow-up, 29% were told by their physician that a follow-up US was unnecessary, 21% forgot to follow-up, 8% did not follow-up for financial reasons, 16% felt better, 5% could not arrange a study, 21% were unsure. One patient died from sepsis before a follow-up scan. Two patients were diagnosed with DVT, one at 7 days follow-up and the other 9 months later (this particular patient had their 7-day scan cancelled by their primary care physician).

CONCLUSION

Patients who were instructed to obtain follow-up lower extremity US examinations to rule out propagation of unseen, distal DVTs did so at a very low rate in our study. One of the largest impediments in our study population was a patients' primary care physician who may not understand the need for a follow-up US examination.

Goal-directed ultrasound in the detection of long-bone fractures

BACKGROUND

New portable ultrasound (US) systems are capable of detecting fractures in the remote setting. However, the accuracy of ultrasound by physicians with minimal ultrasound training is unknown.

METHODS

After one hour of standardized training, physicians with minimal US experience clinically evaluated patients presenting with pain and trauma to the upper arm or leg. The investigators then performed a long-bone US evaluation, recording their impression of fracture presence or absence. Results of the examination were compared with routine plain or computer aided radiography (CT).

RESULTS

58 patients were examined. The sensitivity and specificity of US were 92.9% and 83.3%, and of the physical examination were 78.6% and 90.0%, respectively. US provided improved sensitivity with less specificity compared with physical examination in the detection of fractures in long bones.

CONCLUSION

Ultrasound scans by minimally trained clinicians may be used to rule out a long-bone fracture in patients with a medium to low probability of fracture.

Testicular ultrasound

Acute scrotal pain makes up approximately 0.5% of all complaints presenting to an emergency department. Some of the most com-mon diagnoses for this complaint are testicular torsion and epididymitis. Misdiagnosing testicular torsion can lead to organ loss,cosmetic deformity, and compromised fertility. Modem ultrasound examination of the scrotum is the test of choice for acute scrotal pathology and yields high accuracy compared with surgical exploration. A key component of the testicular examination is use of power and spectral Doppler ultrasonography. Examination of the acute scrotum should not be undertaken unless Doppler capability is available because the evaluation of blood flow is such an important part of diagnosis of testicular torsion, orchitis, epididymitis,trauma, and hemorrhage into a mass.

Ultrasound diagnosis of deep venous thrombosis

The ultrasound diagnosis of deep venous thrombosis by an emergency physician is occurring with increased frequency. The examination is simple to perform and, when combined with a clinical pretest probability or D-dimer, can aid in the rapid disposition ofa patient with lower extremity pain and swelling. The technique and findings of the limited lower extremity ultrasound and the data to support its use in the emergency department are discussed.

Noninvasive intracranial cerebral flow velocity evaluation in the emergency department by emergency physicians

Transcranial Doppler (TCD) is an accepted modality for the evaluation of cerebral blood flow velocities.

OBJECTIVES

The purpose of this study was to test the feasibility of bedside TCD measurement in the emergency department (ED) with critically ill, intubated patients.

METHODS

A prospective convenience sample of patients presenting to a university hospital over a two-month period underwent TCD evaluation of the middle cerebral artery. Intubated patients with head trauma and any patient requiring tracheal intubation were eligible. A 2-MHz Doppler probe was positioned over the temporal bone to acquire blood flow velocities. An emergency medicine resident and research assistant obtained measurements. Continuous TCD tracings were recorded on a video cassette recorder tape for quality assurance review and data collection. Vital signs and therapeutic interventions were also recorded. Flow velocities were measured in cm/s; the peak Resistance Index (RI) was calculated for each patient.

RESULTS

A total of 30 patients were enrolled in the study. Adequate tracings were obtained in 25 patients (83%) without a disruption of resuscitation. Tracings could not be obtained in five patients; they were listed as TCD failures. However, in two of these patients, adequate flow velocity tracings were obtained after resuscitation. Four patients were evaluated during tracheal intubation. One patient was monitored successfully during cardiopulmonary resuscitation. The median time required for data acquisition was 1.9 minutes. The mean highest RI for those who expired was 0.84. For those who survived, the mean highest RI was 0.52. The difference of 0.32 was statistically significant (p = 0.04).

CONCLUSIONS

Noninvasive blood flow velocity monitoring of the middle cerebral artery using TCD is feasible in the ED when performed at the bedside on intubated patients with traumatic brain injury and others during tracheal intubation and resuscitation.

Real-time B-mode ultrasound in the ED saves time in the diagnosis of deep vein thrombosis (DVT)

We hypothesize that EPs can decrease the time to disposition when performing examinations for deep venous thrombosis (DVT) compared with disposition times using imaging specialists (IS). We performed a prospective, single-blind observational study at an academic ED over the course of 1 year. Patients were enrolled based on study physician availability. EPs ordered the corroborative ultrasound, then performed their own examination. EPs recorded patient triage time, ED results, and disposition times for both EP and IS departments. One hundred fifty-six patients were enrolled. Thirty-four (22%) were diagnosed with a DVT. Mean time from triage to EP disposition was 95 minutes and mean time from triage to radiology disposition was 220 minutes. The difference of 125 minutes was statistically significant (P <.0001). EPs and ISs had excellent agreement (kappa = 0.9). Compression ultrasound performed by EPs resulted in a significant decreased time to disposition. Agreement with ISs was excellent.

Resident-performed compression ultrasonography for the detection of proximal deep vein thrombosis: fast and accurate

OBJECTIVES

To assess whether emergency medicine residents (EMRs) could quickly perform accurate compression ultrasonography (CUS) for the detection of proximal lower extremity deep vein thromboses (PLEDVTs) with minimal training.

METHODS

A prospective, observational study using a convenience sample of patients presenting with signs and/or symptoms for PLEDVT. Vascular laboratory and department of radiology studies were considered the criterion standard. CUS of the femoral vessels was performed. Incompressibility or visualized thrombus was considered "positive."

RESULTS

Eight residents with limited ultrasound (US) experience and no prior experience with deep vein thrombosis (DVT) US volunteered to participate in this study, enrolling 72 patients. Their average scan time was 11.7 minutes (95% CI = 9.4 to 14). There were 23 true positives, 4 false positives, 45 true negatives, and 0 false negatives. The test characteristics for PLEDVT gave a sensitivity of 100% (95% CI = 82.2 to 100) and a specificity of 91.8% (95% CI = 79.5 to 97.4).

CONCLUSION

Emergency medicine residents with limited US experience were able to quickly perform CUS after minimal training for the detection of PLEDVT in a select group of patients.

Comparison of perceived and actual times spent by residents performing ultrasound examinations on patients

Emergency medicine (EM) ultrasonography (US) has become a part of residency education. More residents will be taking time during their shifts to perform bedside US examinations for educational purposes, thus further challenging time resources.

OBJECTIVES

The authors' hypothesis was that EM residents could accurately estimate the amount of time spent on an US examination of a patient, thus being able to determine when too much time is being taken away from other duties.

METHODS

The authors performed a prospective, single-blind observational study over a four-month period of EM residents at a large community hospital emergency department (ED) with an EM residency program. When a study physician was present, residents were observed and timed from plugging in the machine to turning it off. The residents, who were not aware of the study, were then asked how long the examination had taken. The true scan time, perceived scan time by the resident, and whether the department was busy or not were recorded on standardized quality assurance data sheets by the study physician. When all beds in the department were occupied, the ED was considered to be busy; otherwise, it was noted as not busy. Statistical analysis included descriptive statistics, paired Student's t-test to compare perceived and actual scan times, and correlation analysis to evaluate for any effect of how busy the ED was on accuracy of perceived times.

RESULTS

Ninety-three observations were made on 17 different residents. The mean perceived time of examinations was 8 min 12 sec (95% CI = 6:42 to 9:42); the mean actual time was 9 min 53 sec (95% CI = 8:29 to 11:18). The difference of 1 min 42 sec (95% CI = 0:37 to 2:47) yielded a p = 0.003. Residents underestimated the time spent on the scan 64 of 93 (69%) times. How busy the ED was did not affect accuracy.

CONCLUSIONS

In this study, residents underestimated the amount of time spent performing an ultrasound examination. The small difference between the actual and perceived scan times was statistically significant; the clinical significance of this time difference is not known.

Elevated intracranial pressure detected by bedside emergency ultrasonography of the optic nerve sheath

Patients with altered level of consciousness may be suffering from elevated intracranial pressure (EICP) from a variety of causes. A rapid, portable, and noninvasive means of detecting EICP is desirable when conventional imaging methods are unavailable.

OBJECTIVES

The hypothesis of this study was that ultrasound (US) measurement of the optic nerve sheath diameter (ONSD) could accurately predict the presence of EICP.

METHODS

The authors performed a prospective, blinded observational study on emergency department (ED) patients with a suspicion of EICP due to possible focal intracranial pathology. The study was conducted at a large community ED with an emergency medicine residency program and took place over a six-month period. Patients suspected of having EICP by an ED attending were enrolled when study physicians were available. Unstable patients were excluded. ONSD was measured 3 mm behind the globe using a 10-MHz linear probe on the closed eyelids of supine patients, bilaterally. Based on prior literature, an ONSD above 5 mm on ultrasound was considered abnormal. Computed tomography (CT) findings defined as indicative of EICP were the presence of mass effect with a midline shift 3 mm or more, a collapsed third ventricle, hydrocephalus, the effacement of sulci with evidence of significant edema, and abnormal mesencephalic cisterns. For each patient, the average of the two ONSD measurements was calculated and his or her head CT scans were evaluated for signs of EICP. Student's t-test was used to compare ONSDs in the normal and EICP groups. Sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

Thirty-five patients were enrolled; 14 had CT results consistent with EICP. All cases of CT-determined EICP were correctly predicted by ONSD over 5 mm on US. One patient with ONSD of 5.7 mm in one eye and 3.7 mm in the other on US had a mass abutting the ipsilateral optic nerve; no shift was seen on CT. He was placed in the EICP category on his data collection sheet. The mean ONSD for the 14 patients with CT evidence of EICP was 6.27 mm (95% CI = 5.6 to 6.89); the mean ONSD for the others was 4.42 mm (95% CI = 4.15 to 4.72). The difference of 1.85 mm (95% CI = 1.23 to 2.39 mm) yielded a p = 0.001. The sensitivity and specificity for ONSD, when compared with CT results, were 100% and 95%, respectively. The positive and negative predictive values were 93% and 100%, respectively.

CONCLUSIONS

Despite small numbers and selection bias, this study suggests that bedside ED US may be useful in the diagnosis of EICP.

Color doppler in the diagnosis of ectopic pregnancy in the emergency department: is there anything beyond a mass and fluid?

Pregnant patients with first trimester complications are a common presentation in many Emergency Departments (EDs). The burden of disproving the existence of an ectopic pregnancy falls on the Emergency Physician (EP). This may be a difficult task depending on the availability of specialty backup and radiologic services. For more than a decade EPs have documented use of bedside ultrasonography for ruling out cases of ectopic pregnancy. Now, with the entry of newer technology into many emergency ultrasound programs, color Doppler is available to an increasing number of EPs. Color Doppler is used as an adjunct to diagnosing ectopic pregnancy by both radiology and gynecology practitioners and can at times provide critical information regarding early pregnancy. Presented are three cases of ectopic pregnancy diagnosed on the basis of abnormal color Doppler findings, and a discussion of the technique.

[Venous compression ultrasonography of the lower limbs: a diagnostic tool in the hands of pneumologists]

Our objective was to study agreement between the compression ultrasound images taken in our respiratory medicine department and the duplex ultrasound images obtained by radiologists at our hospital for patients admitted to our ward with suspected diagnoses of venous thromboembolism.Seventy-eight consecutive patients admitted to our respiratory medicine ward suspected of venous thromboembolism were enrolled. Both types of images were available for all patients studied. Agreement was 90% with a Kappa coefficient of 0.81. Agreement between the two techniques was good. Therefore, compression ultrasonography is a technique that can be handled by respiratory medicine specialists for the diagnosis of venous thromboembolism.

The use of ultrasound by breast surgeons in outpatients: an accurate extension of clinical diagnosis

AIMS

To assess the accuracy of breast ultrasound scan (USS) performed by a surgeon in outpatients and to evaluate the additional contribution of USS to clinical diagnosis.

METHODS

A prospective study of 302 patients with symptomatic breast disease (322 lumps) was performed. Group 1 consisted of 213 clinic USS of lumps surgically removed for appropriate clinical indications. In Group 2, a USS was performed on 231 lumps by both the surgeon and radiologists as part of triple assessment. Each clinic USS was compared to the surgical pathology (Group 1) or USS performed by the radiologist (Group 2).

RESULTS

In Group 1 (n=213), 89 lumps were proven benign and 124 malignant on histology. Ultrasound scans performed by the surgeon compared to histology had a sensitivity of 98.3% and specificity of 91.7%. An abnormal clinic USS heightened the index of suspicion in 22/213 (10.3%) of cases felt clinically to be benign but subsequently confirmed malignant on histology. Fifty-seven lumps felt to be indeterminate clinically were correctly identified on USS by surgeon as benign (n=56) or malignant (n=1). In Group 2 (n=231), there was complete concordance of USS scans by surgeon and radiologists in 197 (96%) and complete discordance in eight (3.9%) patients. Of the discordant scans, the surgeon correctly identified 7/8 diagnoses on histology. A USS examination by the radiologists provided a correct diagnosis of 6/14 scans scored by the clinician as indeterminate.

CONCLUSION

USS performed in outpatients by a breast surgeon is accurate and a useful adjunct to clinical assessment. This enables rapid diagnosis in one-stop breast clinics, selecting difficult diagnostic procedures for USS by radiologists at the same visit.

The diagnosis of lower extremity deep venous thrombosis

The diagnosis of lower extremity deep venous thrombosis (DVT) is critical to emergency physicians because of the risk of pulmonary embolism. This article reviews the diagnostic modalities available for patients with suspected lower extremity DVT. The use of compression ultrasonography and the recent advances in the D-dimer assays are emphasized. A clinical algorithm that utilizes a non invasive approach to this potentially life threatening disease is presented.