J. Christian Fox

A Prospective Evaluation of Emergency Department Bedside Ultrasonography for the Detection of Acute Cholecystitis

STUDY OBJECTIVE We assess the diagnostic accuracy of emergency physician-performed bedside ultrasonography and radiology ultrasonography for the detection of cholecystitis, as determined by surgical pathology. METHODS We conducted a prospective, observational study on a convenience sample of emergency department (ED) patients presenting with suspected cholecystitis from May 2006 to February 2008. Bedside gallbladder ultrasonography was performed by emergency medicine residents and attending physicians at an academic institution. Emergency physicians assessed for gallstones, a sonographic Murphys sign, gallbladder wall thickness, and pericholecystic fluid, and the findings were recorded before formal imaging. The test characteristics of bedside and radiology ultrasonography were determined by comparing their respective results to pathology reports and clinical follow-up at 2 weeks. RESULTS Of the 193 patients enrolled, 189 were evaluated by bedside ultrasonography. Forty-three emergency physicians conducted the ultrasonography, and each physician performed a median of 2 tests. After the bedside ultrasonography, 125 patients received additional radiology ultrasonography. Twenty-six patients underwent cholecystectomy, 23 had pathology-confirmed cholecystitis, and 163 were discharged home to follow-up. Twenty-five were excluded (23 lost to follow-up and 2 unavailable pathology). The test characteristics of bedside ultrasonography were sensitivity 87% (95% confidence interval [CI] 66% to 97%), specificity 82% (95% CI 74% to 88%), positive likelihood ratio 4.7 (95% CI 3.2 to 6.9), negative likelihood ratio 0.16 (95% CI 0.06 to 0.46), positive predictive value 44% (95% CI 29% to 59%), and negative predictive value 97% (95% CI 93% to 99%). The test characteristics of radiology ultrasonography were sensitivity 83% (95% CI 61% to 95%), specificity 86% (95% CI 77% to 92%), positive likelihood ratio 5.7 (95% CI 3.3 to 9.8), negative likelihood ratio 0.20 (95% CI 0.08 to 0.50), positive predictive value 59% (95% CI 41% to 76%), and negative predictive value 95% (95% CI 88% to 99%). CONCLUSION The test characteristics of emergency physician-performed bedside ultrasonography for the detection of acute cholecystitis are similar to the test characteristics of radiology ultrasonography. Patients with a negative ED bedside ultrasonography result are unlikely to require cholecystectomy or admission for cholecystitis within 2 weeks of their initial presentation.

Test characteristics of focused assessment of sonography for trauma for clinically significant abdominal free fluid in pediatric blunt abdominal trauma.

OBJECTIVES Focused assessment of sonography in trauma (FAST) has been shown useful to detect clinically significant hemoperitoneum in adults, but not in children. The objectives were to determine test characteristics for clinically important intraperitoneal free fluid (FF) in pediatric blunt abdominal trauma (BAT) using computed tomography (CT) or surgery as criterion reference and, second, to determine the test characteristics of FAST to detect any amount of intraperitoneal FF as detected by CT. METHODS This was a prospective observational study of consecutive children (0-17 years) who required trauma team activation for BAT and received either CT or laparotomy between 2004 and 2007. Experienced physicians performed and interpreted FAST. Clinically important FF was defined as moderate or greater amount of intraperitoneal FF per the radiologist CT report or surgery. RESULTS The study enrolled 431 patients, excluded 74, and analyzed data on 357. For the first objective, 23 patients had significant hemoperitoneum (22 on CT and one at surgery). Twelve of the 23 had true-positive FAST (sensitivity = 52%; 95% confidence interval [CI] = 31% to 73%). FAST was true negative in 321 of 334 (specificity = 96%; 95% CI = 93% to 98%). Twelve of 25 patients with positive FAST had significant FF on CT (positive predictive value [PPV] = 48%; 95% CI = 28% to 69%). Of 332 patients with negative FAST, 321 had no significant fluid on CT (negative predictive value [NPV] = 97%; 95% CI = 94% to 98%). Positive likelihood ratio (LR) for FF was 13.4 (95% CI = 6.9 to 26.0) while the negative LR was 0.50 (95% CI = 0.32 to 0.76). Accuracy was 93% (333 of 357, 95% CI = 90% to 96%). For the second objective, test characteristics were as follows: sensitivity = 20% (95% CI = 13% to 30%), specificity = 98% (95% CI = 95% to 99%), PPV = 76% (95% CI = 54% to 90%), NPV = 78% (95% CI = 73% to 82%), positive LR = 9.0 (95% CI = 3.7 to 21.8), negative LR = 0.81 (95% CI = 0.7 to 0.9), and accuracy = 78% (277 of 357, 95% CI = 73% to 82%). CONCLUSION In this population of children with BAT, FAST has a low sensitivity for clinically important FF but has high specificity. A positive FAST suggests hemoperitoneum and abdominal injury, while a negative FAST aids little in decision-making.

Prospective evaluation of emergency physician performed bedside ultrasound to detect acute appendicitis

Objectives To evaluate the accuracy of emergency physicians using bedside ultrasound to detect appendicitis (BUSA). Methods Patients presenting to the emergency department with a clinical suspicion of appendicitis were prospectively enrolled and received a 5-min BUSA. Patients received routine work-up for acute appendicitis as deemed appropriate by the attending physician. Radiologists and consulting surgeons were blinded to BUSA results. The criterion standard for the presence or absence of acute appendicitis was the pathology report for patients who received appendectomies, and telephone follow-up for patients discharged home without surgical intervention. Results A total of 132 patients were enrolled. In 44 cases BUSA was positive. Of these, 37 had surgical pathology reports consistent with acute appendicitis, whereas seven did not have appendicitis. In 82 cases, BUSA was negative. Of these, 62 were determined not to have appendicitis, whereas 20 had appendicitis by pathology. Sensitivity for BUSA was 65% [95% confidence interval (CI) 52–76], specificity was 90% (95% CI 81–95), positive predictive value was 84% (95% CI 71–92), and negative predictive value was 76% (95% CI 65–84). The likelihood ratio of a positive BUSA was 6.4 (95% CI 3.1–13.2). Five patients discharged home with a diagnosis other than appendicitis were unable to be reached by telephone, and were excluded from data analysis. Conclusion Our study gives insufficient evidence to support the use of bedside ultrasound by emergency physicians to rule out appendicitis. The high specificity in our study, however, suggests that with further training, BUSA may be useful to rule-in appendicitis in some patients.

AIUM practice guideline for the performance of the focused assessment with sonography for trauma (FAST) examination.

The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use of ultrasound in medicine through professional and public education, research, development of guidelines, and accreditation. To promote this mission, the AIUM is pleased to publish, in conjunction with the American College of Emergency Physicians (ACEP), this AIUM Practice Guideline for the Performance of the Focused Assessment With Sonography for Trauma (FAST) Examination. We are indebted to the many volunteers who contributed their time, knowledge, and energy to bringing this document to completion. The AIUM represents the entire range of clinical and basic science interests in medical diagnostic ultrasound, and with hundreds of volunteers, the AIUM has promoted the safe and effective use of ultrasound in clinical medicine for more than 50 years. This document and others like it will continue to advance this mission. Practice guidelines of the AIUM are intended to provide the medical ultra-sound community with guidelines for the performance and recording of high-quality ultrasound examinations. The guidelines reflect what the AIUM considers the minimum criteria for a complete examination in each area but are not intended to establish a legal standard of care. AIUM-accredited practices are expected to generally follow the guidelines with the recognition that deviations from the guidelines will be needed in some cases depending on patient needs and available equipment. Practices are encouraged to go beyond the guidelines to provide additional service and information as needed by their referring physicians and patients.

A PILOT STUDY EXAMINING THE VIABILITY OF A PREHOSPITAL ASSESSMENT WITH ULTRASOUND FOR EMERGENCIES (PAUSE) PROTOCOL

BACKGROUND Prehospital ultrasound has been shown to aid in the diagnosis of multiple conditions that do not generally change prehospital management. On the other hand, the diagnoses of cardiac tamponade, tension pneumothorax, or cardiac standstill may directly impact patient resuscitation in the field. STUDY OBJECTIVE To determine if prehospital care providers can learn to acquire and recognize ultrasound images for several life-threatening conditions using the Prehospital Assessment with UltraSound for Emergencies (PAUSE) protocol. METHODS This is a prospective, educational intervention pilot study at an urban fire department with integrated emergency medical services (EMS). We enrolled 20 emergency medical technicians--paramedic with no prior ultrasonography training. Subjects underwent a 2-h training session on basic ultrasonography of the lungs and heart to evaluate for pneumothorax, pericardial effusion, and cardiac activity. Subjects were tested on image interpretation as well as image acquisition skills. Two bedside ultrasound-trained emergency physicians scored images for adequacy. Image interpretation testing was performed using pre-obtained ultrasound clips containing normal and abnormal images. RESULTS All subjects appropriately identified the pleural line, and 19 of 20 paramedics achieved a Cardiac Ultrasound Structural Assessment Scale score of ≥4. For the image interpretation phase, the mean PAUSE protocol video test score was 9.1 out of a possible 10 (95% confidence interval 8.6-9.6). CONCLUSION Paramedics were able to perform the PAUSE protocol and recognize the presence of pneumothorax, pericardial effusion, and cardiac standstill. The PAUSE protocol may potentially be useful in rapidly detecting specific life-threatening pathology in the prehospital environment, and warrants further study in existing EMS systems.

Integration of Ultrasound in Medical Education at United States Medical Schools: A National Survey of Directors' Experiences.

Despite the rise of ultrasound in medical education (USMED), multiple barriers impede the implementation of such curricula in medical schools. No studies to date have surveyed individuals who are successfully championing USMED programs. This study aimed to investigate the experiences with ultrasound integration as perceived by active USMED directors across the United States.

Web‐based lectures, peer instruction and ultrasound‐integrated medical education

with the statement: ‘I would utilise a PBL case in the future to facilitate a group process.’ Half of the respondents reported that using the PBL case advanced the group process and half indicated that the PBL case helped in some ways and hindered in others. Generally, there was satisfaction with this approach related to its contribution towards facilitating group process and generating discussion. Members commented about having a clearer understanding of the mission statement. Conversely, the structured nature of PBL was seen by some as impeding brainstorming. The use of a PBL case was successful in providing structure to group members for a complex problemsolving and creative task. This approach provided an opportunity for all group members to participate in discussion, create a common understanding of the elements of the problem, and identify and seek clarification of learning issues as needed. It also helped the group to share a conceptual mental model as they progressed through the case. Although the task for this group was related to curriculum redesign, this is a process-based approach that can be adapted to multiple situations and medical school contexts in which problem solving is the goal.

Thyroid and parathyroid ultrasound examination

These guidelines are an educational tool designed to assist practitioners in providing appropriate radiologic care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the American College of Radiology cautions against the use of these guidelines in litigation in which the clinical decisions of a practitioner are called into question.

Integration of Ultrasound in Undergraduate Medical Education at the California Medical Schools A Discussion of Common Challenges and Strategies From the UMeCali Experience

Since the first medical student ultrasound electives became available more than a decade ago, ultrasound in undergraduate medical education has gained increasing popularity. More than a dozen medical schools have fully integrated ultrasound education in their curricula, with several dozen more institutions planning to follow suit. Starting in June 2012, a working group of emergency ultrasound faculty at the California medical schools began to meet to discuss barriers as well as innovative approaches to implementing ultrasound education in undergraduate medical education. It became clear that an ongoing collaborative could be formed to discuss barriers, exchange ideas, and lend support for this initiative. The group, termed Ultrasound in Medical Education, California (UMeCali), was formed with 2 main goals: to exchange ideas and resources in facilitating ultrasound education and to develop a white paper to discuss our experiences. Five common themes integral to successful ultrasound education in undergraduate medical education are discussed in this article: (1) initiating an ultrasound education program; (2) the role of medical student involvement; (3) integration of ultrasound in the preclinical years; (4) developing longitudinal ultrasound education; and (5) addressing competency.

Emergency and Critical Care Imaging

Care for patients who have time-sensitive disease processes in the emergency department and critical care settings is optimized with rapid diagnosis and intervention. Recent advances in medical imaging have increased portability, decreased image acquisition time, improved data resolution, and increased use of noninvasive studies. This article discusses the use of portable imaging techniques such as bedside ultrasound and radiography as well as CT and CT angiography in the diagnosis and care of critically ill patients.