Emergency Ultrasound Section Newsletter - February 2012
|From the Chair - Emergency Ultrasound Section Newsletter, February 2012|
|ACEP US Section Billing and Reimbursement Survey Results - Emergency Ultrasound Section Newsletter, February 2012|
|Emergency Ultrasound Tips and Tricks - Emergency Ultrasound Section Newsletter, February 2012|
|Ask the Expert - Emergency Ultrasound Section Newsletter, February 2012|
|Case Report: Back Pain in a 78yo Female, Now Resolved - Emergency Ultrasound Section Newsletter, February 2012|
|Pediatric Ultrasound Tricks of the Trade: Abdominal Ultrasound - Emergency Ultrasound Section Newsletter, February 2012|
|Summary of Listserve Discussions - Emergency Ultrasound Section Newsletter, February 2012|
|Technical Updates - Emergency Ultrasound Section Newsletter, February 2012|
|Journal Watch - Emergency Ultrasound Section Newsletter, February 2012|
From the Chair - Emergency Ultrasound Section Newsletter, February 2012
Michael Stone, MD, RDMS
I would like to take this opportunity to wish you all a Happy New Year, to review what the ACEP ultrasound section is working on, and to discuss how we hope to further point-of-care ultrasound. ACEP will continue to provide leadership - as it always has - in promoting point-of-care ultrasound for clinicians across a variety of practice settings. Here is a look at some of our current projects and priorities:
- There is a continually growing collection of documents and resources out there for community and academic physicians using point of care ultrasound, as well as those who are managing point of care ultrasound programs. ACEP has completed the redesign process of our Section Web page and our website subcommittee has assembled these documents and resources in a more accessible and navigation-friendly environment. Check out the new site at www.acep.org/ultrasound and please send any feedback my way.
Coming soon: a web forum for recurrent topics of discussion, references to pertinent literature that can be used to support EUS practice, and an expanded list of resources for program directors.
- The section continues to support and advance research and publications in point of care ultrasound as much as possible. We are actively pursuing new grant opportunities for section members to help promote outcomes research, but all forms of EUS research (from case reports to prospective trials) are still of great value to our members and community. Regardless of your practice environment, we really encourage you to contribute to the growing body of literature on point of care sonography. If we can be of any help, please don’t hesitate to contact us!
The Section continues its work on subspecialty development, fellowship guidelines and educational resources for practitioners of all levels. There are many other active subcommittees and we can always use more participation: please contact me with any suggestions, feedback or interest in becoming more involved with the Section’s efforts. Thanks and have a great and productive 2012!
ACEP US Section Billing and Reimbursement Survey Results - Emergency Ultrasound Section Newsletter, February 2012
Jessica Resnick, MD, FACEP
We conducted a survey of the American College of Emergency Physicians (ACEP) Emergency Ultrasound Section list-serve to evaluate the successes and challenges in reimbursement for point-of-care ultrasound. A web-based survey was emailed to the 700 members of the ACEP Emergency Ultrasound Section list-serve. Sixty-three list-serve members responded from 29 states across the United States. Sites included academic emergency departments with residents (54%), community emergency departments with residents (22%), community emergency departments with no residents (22%), and academic emergency departments with no residents (1%).
Sixty percent of participants are billing for the professional component of the ultrasound studies. Forty-two percent of participants report their departments are billing for the technical component. The greatest barrier to billing is insurance companies rejecting payment based primarily on two issues:
- refusing to accept the ultrasound study as a separately identifiable service from the evaluation and management code
- refusing to recognize emergency physicians’ training as adequate to interpret and bill. Other common challenges include political obstacles within the hospital and time to archive and document a report.
Twenty-two percent of respondents are reimbursed consistently, defined as getting reimbursed 75-100% of the time, for the professional component of ultrasound studies. Thirty-seven percent are reimbursed in 0-25% of cases. There is an equal distribution of studies that are being rejected. The most frequent payors cited are the Center for Medicare and Medicaid Services and Cigna. The least frequent payors (ie, most rejections) cited are United Healthcare, Anthem Blue Cross/Blue Shield, Aetna, and Humana. Thirty-three percent of respondents did not have the knowledge to adequately answer reimbursement questions.
During the second decade of ultrasound use by emergency physicians, billing and reimbursement continued to be a secondary consideration for many programs. As emergency ultrasound adoption accelerated, education, training, acquisition of equipment, and credentialing have been higher priorities. Programs are now recognizing that the sustained financial viability of ultrasound programs requires fair reimbursement. While political obstacles within hospitals remain, the number one cited challenge in this survey is private insurance companies rejecting payment.
Both governmental and non-governmental insurance companies are increasing their stewardship efforts. The Centers for Medicare services has issued three recent documents that are relevant to emergency department ultrasound reimbursement: Medicare Part B Billing for Ultrasound (July 2009), Medicare Payments for Diagnostic Studies in Emergency Departments (April 2011), and Multiple Procedure Payment Reduction (MPPR) on certain diagnostic imaging procedures (January 2012). The first document from July 2009 looked for over-utilization of ultrasound throughout the country as well as abnormal patterns in billing. The OIG evaluated Part B technical components for ultrasound billing across the US and then published their MPPR for facility billing. This month, the MPPR applies to professional billing as well. The April 2011 document evaluates billing for diagnostic studies in the emergency department and supports the contemporaneous interpretation of studies during the patient’s emergency department length of stay. CMS requires an order to be in the record as well as a written report for proper billing. Emergency physicians can easily meet these CMS requirements. Unfortunately the requirements for non-governmental payors are less transparent and rely more on trial and error and time-consuming appeal letters. Private insurers are not required to follow CMS regulations.
ACEP members need additional support to increase their general knowledge of ultrasound coding and reimbursement. Furthermore, help is needed when appealing to non-governmental payors in order to receive fair payment for services that go beyond evaluation and management codes. ACEP’s billing hassle log has a new option to monitor for such ultrasound bundling as well as a form appeal letter. Additional ultrasound related feedback within this billing hassle log will encourage ACEP to focus additional resources on this increasingly vital problem.
Emergency Ultrasound Tips and Tricks - Emergency Ultrasound Section Newsletter, February 2012
John T Powell MD, Jennifer T Mink MD RDMS, Paul R Sierzenski MD RDMS, and Jason T Nomura MD RDMS
Patients commonly present with complaints of abdominal hernias and are frequent incidental findings in the emergency department. Incarcerated hernias can cause swelling, pain, and may require emergent surgical consultation if strangulated.
While an incarcerated hernia can be found on physical exam, ultrasound can assist in the management of these cases. Imaging the incarcerated hernia to identify the contents of hernia sac can help differentiate bowel from adipose tissue. As well, one can identify concomitant pathology such as free fluid, bowel wall thickening, pneumotosis coli, aperistalsis, and abnormal blood flow.
Diagnostic imaging is commonly described in many texts and articles; however, an additional step in the imaging protocol can help with the management of incarcerated hernias. Scan through the hernia sac and pay special attention to the abdominal wall for the break in the wall or the neck of hernia sac, this will allow planning for reduction. Identification of the neck allows the operator to direct the hernia contents toward the neck during manual reduction. It also allows the clinician to identify the size of the neck compared to the hernia contents.
Figure 1 shows an incarcerated ventral hernia containing small bowel. The neck can be identified by the defect in the abdominal wall. This hernia was successfully reduced by applying pressure from the lateral edge of the bowel loop toward the neck. Figure 2 shows the hernia post reduction containing only fat; the fascial defect is still visible.
While this large hernia had a midline neck, that is not always the case as demonstrated in Figure 3. The neck is visible and the hernia sac is laterally located. Evaluation of the hernia contents and neck location can aid in planning the reduction. Practice visualizing known hernias and the fascial defect or neck on patients with hernias that are not incarcerated or strangulated.
Figure 1: Incarcerated hernia with bowel and neck visualized.
Figure 2: Post reduction the fat containing hernia and neck are visualized.
Figure 3: Small hernia sac that is lateral to the neck.
Ask the Expert - Emergency Ultrasound Section Newsletter, February 2012
Resa E Lewiss MD RDMS
Director of Emergency Ultrasound
St. Luke’s/Roosevelt Hospital Center
Assistant Clinical Director of Medicine
Columbia University College of Physicians and Surgeons
Section Editor: Robert Bramante, MD
Question: When performing ultrasound examinations to evaluate for AAA, should emergency physicians also routinely evaluate the common iliac arteries?
I would like to first thank Drs. Robert Bramante, Chris Raio and the ACEP Ultrasound Section Newsletter committee for inviting me to participate in this interesting series. I have focused my response with the underlying premise that the emergency ultrasound examination (EUS) of the abdominal aorta (AA) includes as a criterion minimum, a measurement of the proximal common iliac arteries at the bifurcation of the distal AA. The focused question then is When performing ultrasound examinations to evaluate for AAA, should Emergency Physicians also routinely evaluate the common iliac arteries for solitary iliac artery aneurysms?
The 2006 ACEP Emergency Ultrasound Imaging Criteria Compendium policy categorizes evaluation of the common iliac arteries for aneurysm as an extended indication for an abdominal aortic aneurysm (AAA) examination.(1) This document and the updated 2010 American College of Radiology-American Institute of Ultrasound in Medicine practice guidelines for screening the abdominal aorta in adults both specify that the common iliac arteries should be measured in the proximal right and left common iliac arteries just below the bifurcation in the evaluation for AAA.(2)
Aneurysms of the iliac arteries usually occur in conjunction with an AAA. A solitary iliac artery aneurysm (SIA) is defined as a twofold increase in the size of the iliac artery without a coexisting aneurysm at another location. Most of the published information on SIAs comes from the general surgery and vascular surgical literature, which focus on operative management, and outcome measures such as morbidity and mortality. Generally accepted as rare relative to AAAs, SIAs have incidence rates ranging from 2-11%. (3,4) In their retrospective case series from Japan covering a twenty-year period, Hu et al reported a 5% (N =28) incidence of SIAs among all aorto-iliac aneurysms for that time period.(3) Krupski et all reported in a 13-year retrospective chart review on 31 cases of SIAs defined as a maximal diameter of at least 2.5 cm as measured by CT scan. The mean age of patients in this series was 69 +/- 8 years. 43% of the cases presented asymptomatically and were diagnosed on physical examination ie, palpation or by a radiographic study. All received a pre-operative CT scan and only 7 had a screening ultrasound.(4)
The emergency medicine literature supports that emergency physicians (EP)s accurately perform and measure the AA with EUS. Published studies have demonstrated that EPs are able to obtain accurate measurements of the AA diameter as compared to CT scan and are able to detect AAA accurately.(5, 6) Knaut et al. specifically demonstrated that relatively inexperienced sonographers could obtain measurements at the AA bifurcation with reasonable accuracy.(5) In a prospective observational study of 125 patients evaluated for AAA in the ED over a 2-year period, Tayal et al. reported that EPs could detect AAA by EUS with 100% sensitivity, 98% specificity 93% positive predictive value and 100% negative predictive value.(7)
Limitations for evaluating the common iliac arteries mirror those for evaluating the AA more proximally ie, overlying bowel gas, an obese patient, or a patient in pain. In their retrospective observational study, Blaivas and Theodoro published findings, which resonate with most EPs experienced in EUS of the AA ie, the inability to sonographically visualize the entire length of the AA in emergency patients. In 17 of 207 (8%) of these patients, a significant portion (one third or more) of the aorta was not visualized theoretically leaving an AAA undiscovered. In this retrospective observational study, the authors did not specifically mention identification of the bifurcation as a measurement criterion. No AAAs were missed and all patients presenting with an AAA in that time period were discovered.(8)
At our institution, the minimal criteria for EUS evaluation of the AA requires physician sonographers to measure the proximal iliac arteries at the bifurcation- specifically in a transverse anterior-posterior plane with diameter measured from the outer wall to the outer wall. We do not routinely perform a more complete evaluation of the common iliac arteries. In light of this brief review composed of retrospective surgical literature reporting a wide range of incidence rates of SIA and EM literature supporting EP performed EUS of the AA, I do not think that EPs need to routinely evaluate the common iliac arteries for SIAs. However, the evidence suggests that EPs are capable of competently performing a more detailed evaluation of the common iliac arteries and would obtain accurate measurements- as long as the vessels are visible sonographically. A focused evaluation of the iliac arteries is necessary when there is a strong suspicion for an aneurysm despite a normal EUS examination of the AA. Other imaging modalities will remain the standard when SIA is strongly suspected at least for the present time until prospective studies focus on this question.
- American College of Emergency Physicians. Emergency Ultrasound Imaging Criteria Compendium. Ann Emerg Med. 2006. Oct;48(4):487-510.
- ACR-AIUM Practice Guideline for the Performance of Diagnostic and Screening Ultrasound of the Abdominal Aorta in Adults. 2010 Resolution 34.
- Hu H, Takano T, Guntani A, et al. Treatment of solitary iliac aneurysms: clinical review of 28 cases. Surg Today. 2008;38(3):232-6.
- Krupski WC, Selzman CH, Floridia R, et al. Contemporary management of isolated iliac aneurysms. J Vasc Surg. 1998;28(1):1-11; discussion 11-3.
- Knaut AL, Kendall JL, Patten R, Ultrasonographic measurement of aortic diameter by emergency physicians approximates results obtained by computed tomography. J Emerg Med. 2005;28(2):119-26.
- Costantino TG, Bruno EC, Handly N, et al. Accuracy of emergency medicine ultrasound in the evaluation of abdominal aortic aneurysm. J Emerg Med. 2005;29(4):455-60.
- Tayal VS, Graf CD, Gibbs MA. Prospective study of accuracy and outcome of emergency ultrasound for abdominal aortic aneurysm over two years. Acad Emerg Med. 2003;10(8):867-71.
- Blaivas M, Theodoro D. Frequency of incomplete abdominal aorta visualization by emergency department bedside ultrasound. Acad Emerg Med. 2004 Jan;11(1):103-5.
Case Report: Back Pain in a 78yo Female, Now Resolved - Emergency Ultrasound Section Newsletter, February 2012
Meghan Kelly Herbst, MD
Emergency Ultrasound Director
Chief Complaint: Back Pain, now resolved
(please place the Figures as below)
Figure 2 (File name: Case_rpt_aortic_Fig2.jpg)
1) Is this a normal cardiac echo?
2) What is your diagnosis?
3) What is the next step in management?
A 78yo female, Mrs. X, presented to the ED with complaint of abrupt transient back pain that resolved upon arrival. She was in a stretcher in the back hallway, comfortable, alert and oriented x 4. Vitals: afebrile, RR 12, BP 110/40, HR 60, O2sat 99% on RA.
The ultrasound fellow was asking around if there were any patients to scan and was sent to Mrs. X with a shrug from the attending as it was a slow day and most patients had already been scanned. While the fellow was scanning, the patient was very talkative and pleasant, telling her about her children and grandchildren. When asked about her back pain, she stated it was much better but that earlier, “It was so bad I almost passed out!”
As the fellow listened to her patient, she noted a small but real pericardial effusion, a dilated aortic outflow tract >4cm, and a linear echo within the lumen of the abdominal aorta that moved with each pulsation and continued distally into both iliac arteries. The fellow called in her attending and the patient was sent immediately to radiology for a CTA of the chest, abdomen and pelvis. Cardiothoracic surgery was consulted simultaneously and the patient was transported from the radiology suite directly to the OR. Within one week, she was discharged home, accompanied with her children and grandchildren.
Role of Emergency US:
In this case, bedside ultrasound identified a type A aortic dissection that involved the pericardium proximally and continued down to both iliac arteries. This patient was asymptomatic and in the hallway. She had a low pre-test probability for aortic dissection. However, because bedside ultrasound has a high specificity (99-100%) for visualizing the intimal flap in an aortic dissection, she ruled in for this diagnosis and management was immediately expedited. In this case, bedside ultrasound may have saved her life. It is important to note that the sensitivity of bedside ultrasound for a dissection flap is only 67-80%.(1, 2, 3)
If a pericardial effusion accompanies a dissection flap on ultrasound, a type A aortic dissection is the diagnosis to rule out. Furthermore, a dilated aortic outflow tract (>4cm) is sensitive for a type A aortic dissection.(4,5)
Answers to Questions:
- This patient’s cardiac echo is not normal. It is a subxiphoid view of the heart and shows a small pericardial effusion and a dilatation of the aortic outflow tract.
- Diagnosis: Type A dissection from pericardium down to bilateral iliac arteries with associated pericardial effusion.
- Next step in management: Cardiothoracic surgery consult and OR for repair.
Take Home Points:
- Bedside ultrasound is specific, but not sensitive, for aortic dissection.
- Type A dissections may be associated with pericardial effusions.
- When suspecting a type A aortic dissection, measure the aortic outflow tract at its widest diameter in a parasternal long axis. Normal is <4cm.
- Khandheria BK, Tajik AJ, Taylor CL, et al. Aortic dissection: review of value and limitations of two-dimensional echocardiography in a six-year experience. J Am Soc Echocardogr. 1989; 2: 17-24.
- Victor MF, Mintz GS, Kolter MN, et al. Two-dimensional echocardiographic diagnosis of aortic dissection. Am J Cardiol. 1981; 48: 1155-1159.
- Roudaut RP, Billes MA, Gosse P, et al. Accuracy of M-mode two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 1128 cases. Clin Cardiol. 1988; 11:553-562.
- DeMaria AN, Bommer W, Neumann A, et al. Identification and localization of aneurysms of the ascending aorta by cross-sectional echocardiography. Circulation. 1979; 59:755-761.
- Dubourg O, Delorme G, Gueret P, et al. Diagnosis of acute aortic dissection by echocardiography. Arch Mal Coeur. 1988; 81:21-25.
Pediatric Ultrasound Tricks of the Trade: Abdominal Ultrasound - Emergency Ultrasound Section Newsletter, February 2012
Samuel Lam, MD, RDMS
Assistant Ultrasound Director
Advocate Christ Medical Center
Russ Horowitz, MD, RDMS
Pediatric Emergency Ultrasound Director
Children’s Memorial Hospital
Pediatric bedside ultrasound applications have been gaining in popularity recently. There are several reasons for this, such as better training in emergency medicine residencies and pediatric emergency medicine fellowships, advantages of a no-radiation bedside tool, and the growing literature on various pediatric applications. While many of the “adult” applications can be generalized to the pediatric population, there are some unique pediatric bedside ultrasound applications that require learning of new skill sets. Hence we have developed this section to share such knowledge.
Our first article aims to give the audience some succinct pointers on three pediatric abdominal ultrasound applications. Generally, a high frequency probe is recommended because the anatomical structures we are interested in tend to be quite shallow.
Intussusception Classic teaching is that children with intussusception have a mass in the right upper quadrant and empty right lower quadrant. Although the emergency physician won’t be performing the barium enema reduction, bedside sonographic diagnosis helps prioritize radiology workflow. In hospitals where radiologists are unable to perform intussusception reductions, a bedside diagnosis will help facilitate transfer to an appropriate facility. “I performed a bedside ultrasound and visualized the intussusception” carries more weight than “I think he may have intussusception.”
- Start your search in the RUQ to visualize leading edge of intussception
- Graded compression: Slow, steady pressure on the abdominal cavity in order to displace overlying bowel gas
- Follow the colon (fig.1) or “lawn mower approach” (fig. 2)
| Figure 1|| Figure 2|
Typical Patterns to look for:
- Doughnut/ Target sign: Layers of invaginated bowels seen in cross section (fig. 3)
- Pseudokidney sign: in oblique view (fig. 4)
- Pancake sign: stacked layers of bowel in longitudinal view (fig 5)
Potential Mimics/ Confounders: bowel wall hematoma, enterocolitis, psoas muscle, inflammatory bowel disease
Tip: Stool in colon can mimic intussusception (fig. 6). Though it can be echogenic on ultrasound, stool does not give the layered, concentric view typical of intussusception.
Appendicitis Applies to big kids as well.
- Graded compression
- Scan at point of maximal tenderness
- Most commonly lie between iliac vessels and psoas muscle.
Typical Pattern to look for:
- Non compressible blind ending tubule ≥ 6mm (fig. 7)
- Target sign on cross section (fig. 8)
- Focal free fluid collection (fig. 9)
- Fecalith occasionally (fig. 10). Fecaliths may not shadow!
- Hyperermia surrounding appendix.
Potential Mimics/Confounders: Inflammation from Crohn’s disease/tuboovarian abscess can cause serosal edema and thickening of appendix, inflamed Meckel’s diverticulum
Tips: Specificity high but sensitivity low. Failure to visualize appendix ≠ no appendicitis
Hypertrophic Pyloric Stenosis
- Pylorus is medial to the gallbladder.
- Pylorus is lateral and anterior to the aorta/ superior mesenteric artery
- Find the fluid-filled stomach and follow it distally to the pylorus
Typical Pattern to look for:
- Pyloric muscle is hypoechoic on ultrasound
- Target sign on transverse view (fig. 11)
- Pyloric muscle thickness ≥ 3mm (fig. 12)
- Pyloric channel length ≥ 15 -18 mm (fig.13)
- Lack of gastric emptying
Potential Mimics/Confounders: Tangential section of pyloric muscle can give a false positive result, overdistended stomach can displace the pylorus posteriorly and give a false negative result. Pylorospasm will show a thickened pylorus and delay gastric emptying giving a false positive study.
Tip: Roll child into lateral decubital position and feed child. The stomach will become hypoechoic filled with small hyperechoic air bubbles. Hold probe over pylorus. In children without pyloric stenosis, you will see a steady stream of fluid rush through the pylorus into the small bowel.
Questions? Email Samuel Lam or Russ Horowitz .
Summary of Listserve Discussions - Emergency Ultrasound Section Newsletter, February 2012
Tom Kehrl, MD
As most of us know, there is a lack of a certification or board examination process to distinguish emergency physicians with advanced training and expertise in the various point-of-care ultrasound modalities. The ACEP Ultrasound Section’s Subcommittee on Subspecialty Development began looking at various options in 2007. Discussion began to heat up on the Listserve about a year ago after word that the ACGME officially approved the EMS fellowship and the ABMS pathway to subspecialty recognition.
Different options were discussed, including the ABMS, RPVI, Echocardiography, and RDMS models. Pros and cons of the four choices were discussed and debated. Much of the discussion centered on the ABMS pathway with comparisons to the Medical Toxicology fellowship process.
Frequently mentioned issues included: do we have a unique fund of knowledge? Will an emergency ultrasound fellow be permitted to work as an attending in the ED? How will the presumed changes in fellow salary and fellowship director hours and pay affect different programs? Will an ACGME approved ABMS certification process for emergency ultrasound discourage the use of ultrasound by the non-fellowship trained or non-ultrasound boarded emergency physician?
Presentations were made at both SAEM and ACEPs Scientific Assembly (SA)and there was a significant amount of discussion on the Listserve. After the presentation at SA, section members were asked to vote using a yes/no electronic ballot. With a total of 235 respondents, 71% voted in favor of pursuing the ACGME application for EUS sub-specialty development for emergency ultrasound fellowships. As such, the Section leadership will begin the process to subspecialty recognition for emergency ultrasound and ACGME-approved fellowships.
Recent Posted US Grant Opportunities
AIUM Endowment for Education and Research Grant: Study to Assess Competency of Point-of-Care Applications of Ultrasound
- Purpose: to investigate the reliability of various methods to measure competency in one or more point of care applications in US
- Up to $50,000 for one or more grants
- Deadline March 1, 2012
Technical Updates - Emergency Ultrasound Section Newsletter, February 2012
Laleh Gharahbaghian MD, Zoe Howard MD, and Greg Bell MD
ACEP does not endorse specific simulation equipment and the opinions expressed are those of the authors.
Blue Phantom’s FAST Exam Real-Time Training Model
As one of the most popular manufacturers of ultrasound (US) simulation phantoms, Blue Phantom offers a new simulation tool that is promised to enhance US education of the FAST and TTE scans. It also can function as a pericardiocentesis training model. This human-looking head to thigh model is constructed using Blue Phantom’s patented simulated human tissue. By users utilizing their own US system, this 25K phantom offers the ability to visualize the thorax, abdomen and pelvis while encountering obstacles that we all must overcome: applying enough pressure for visualization, bowel gas and ribs obstructing the view. Adjustable internal bleeding levels allow users to individually vary the training scenarios based on the scenarios being presented.
The VIMEDIX TTE and FAST human appearing head to thigh simulator offers an ability to visualize the thorax, abdomen and pelvis using the VIMEDIX’s transducer that is attached to their computerized control monitor. This is a virtual ultrasound TEE, TTE and FAST simulator without fluid filled structures inside. It allows the ability to visualize, on a split screen, varying layers of surrounding anatomy on one side of the monitor and the ultrasound image on the other. It allows M mode, color and pulsed wave Doppler, 3D animated augmented reality, and then ability to adjust gain and depth.
MedSim’s UltraSim offers an excellent simulator for ultrasound educational training. Its hefty price tag (~$100k) includes a full-size training mannequin with simulator probes that communicate with the UltraSim computer. B-mode, Color and Spectral Doppler modes are all available. The computer houses both normal and abnormal stored images of real patient ultrasound data in diverse disease pathologies.
A highlight is the comprehensive educational component offered by way of its broad selection of modules (Abdomen, Obstetrics, Gynecology, Transvaginal Gynecology, Transvaginal Obstetrics, Breast, Vascular, Neck and Emergency Medicine). Within each module is a curriculum of clinical cases, each with a detailed patient presentation, task list to help guide the learner, image library and case analysis with additional features to enhance the instructor’s evaluation or competency assessment/accreditation. Overall, it is a realistic hands-on ultrasound scanning experience worth checking out!
The SonoMan and SonoMom are the two main teaching ultrasound simulators that Simulab offers. The body form has imbedded targets (258 in the Man and 148 in the Mom) which provide actual patient images. Each of these targets provide images in a transverse and longitudinal plane and a video clip showing the technique for scanning that area. For each normal scan there are five abnormal images depicting the common pathologies that EM residents need to know. An instructor mode provides annotated images to describe what is being seen and important landmarks. The student mode picks normal or abnormal images randomly according to the study application. The SonoMan has six modules including FAST, ECHO, Gallbladder, AAA, and Renal and EFAST which are each sold separately. The SonoMom comes with a 1st trimester module for transabdominal and transvaginal imaging. Both systems come with a tissue-like body core, software which is updated for free with purchase, the probe and a carrying case. The SonoMan is going for $5450 with an expected purchase of at least one module. Modules range from $1050 to $1950. The SonoMom is $6950 and the 1st trimester module is $1950. Simulab always provides special offers with purchases, listed on their website, including such things as a free module when another is being purchased.
Though these are not dynamic teaching simulators, they are relatively inexpensive and are good teaching tools especially for the starting resident to teach image acquisition, landmarks, and some pathology.
SonoSim Ultrasound Training Solution
The SonoSim product is a unique learning tool for the money. Their intention was not to create a simulator, but an integrated tool linking interactive multimedia-based teaching with hands-on dynamic training. The designers intend this to be a near complete introduction to the EM ultrasound curriculum, except for instructor supervision and fine detail learning that takes place at the patient’s bedside. Each of 10 modules covering all of the emergency or critical care applications are taught in two hours of still and dynamic ultrasound imagery, audio narration, computer graphics, and animation. Over 400 questions assess the learners grasp of this material. The SonoSim fixed-point probe is designed to respond to subtle directional movements and to create dynamic real patient images. 150 real patient cases depict an array of normal and pathologic cases. The SonoSim product includes the PC housing the software and the probe for $15,000. The material is updated and expanded continually and these additions are provided free for one year following purchase. SonoSim will soon be offering 20 hours of CME through ACEP for successful completion of all the modules. For a much lower price than some other products the SonoSim teaching tool appears to emphasize well refined multimedia teaching with real patient dynamic scanning; linking the two together to optimize efficient, realistic and comprehensive learning.
Journal Watch - Emergency Ultrasound Section Newsletter, February 2012
Reviewer: Aliasgher Hussain, MD, Harbor-UCLA Medical Center
Article: Hoyer HX, Vogl S, Schiemann U, Haug A, Stolpe E, Michalski T. Prehospital ultrasound in emergency medicine: incidence, feasibility, indications and diagnoses.Eur J Emerg Med. 2010;17(5):254-259.
Objective: The objective of this study is to examine the feasibility, indications, and accuracy of diagnosis by prehospital US.
Methods: This was a prospective, open observational study done over cumulative 3 year period in 4 helicopters, one field vehicle. Four different handheld US systems were used by twelve physicians with a median of 14.4 (±10.4) examinations by each person. A standard protocol was created of essential diagnosis that could be verified or excluded by US. After a quick guided examination, any sonographic procedure performed to find an essential diagnosis was included and documented on an audit form. Exclusion criteria dictated that the US examination should not slow down work flow. Documentation was done retroactively with a retrospective search of hospital results and outcome (within 2 weeks). A time analysis was done during the first 3 months of the study and then again during the last 6 weeks by an independent observer.
Results: 144 US examinations were performed on a possible 971 patients. Of these, 110 (76.4%) patients had clinic results available. The sensitivity was 85% and the specificity was 100% for the essential diagnosis laid out by the protocol. The positive predictive value was 100%, negative predictive value was 95.5% and accuracy was 96.4%. The time analysis during the first 3 months on 22 patients was 1min 54s, which was reduced 56s when repeated during the last 6 weeks on 17 patients.
Discussion: The authors conclude that prehospital US is a feasible tool that can be used for specific essential diagnosis. The limitations of this study include no randomization and it did not quantify if US findings correlated to a change in treatment or disposition.
Reviewer: Lisa Mills, MD, UC Davis Medical Center
Article:Krishnamoorthi R, Ramarajan N, Wang NE, Newman B, Rubesova E, MuellerCM, Barth RA. Effectiveness of a staged US and CT protocol for the diagnosis of pediatric appendicitis: reducing radiation exposure in the age of ALARA.Radiology.2011;259(1):231-239.
Objective: The objective of this study was to evaluate the effectiveness of an algorithm that combines the use of US and CT in the diagnosis of acute appendicitis in children with a goal of reducing CT exposure.
Methods: Retrospective chart review of all children with suspected appendicitis over a 5 year period at the implementation of a multidisciplinary protocol for the approach to appendicitis in pediatric patients, age 2-18years. The protocol called for US as the primary imaging study with follow up CT for equivocal studies (equivocal is “not definitively positive or negative”). US was performed by the Department of Radiology, technologist or resident physician.
Results: In the 1228 cases identified, 631 cases complied with the protocol. The sensitivity and specificity of the staged protocol were 98.6% and 90.6%, respectively. The negative appendectomy rate was 8.1% (19 of 235 patients), and the missed appen- dicitis rate was less than 0.5% (one of 631 patients). CT was avoided in 333 of the 631 patients (53%) in whom the protocol was followed and in whom the US findings were definitive. US provided an alternate diagnosis in 22 patients, including mesenteric adenitis, ovarian abnormality, constipation, colitis, intussusception, and pyelonephritiis.
Discussion: Although it is disappointing that the authors could not collect this information prospectively, it is an interesting study. The definitions of positive, negative, and equivocal scans were clearly established. This study provides more support that US is a good study in the evaluation of acute appendicitis. The fact that alternate diagnoses were identified and that US was the end point for some patients with a negative study further supports the role of US in acute appendicitis. The study reports only 1 missed appendicitis case. However, in addition to this case, there was 1 case of appendicitis with a negative US that went to the OR without CT. This is a miss for US, but not necessarily for the protocol. One limitation is that there is little analysis of why the protocol was not followed in nearly 50% of cases. This study continues to support the use of US as the initial evaluation of acute appendicitis in children.
Reviewer: Sam Hsu, MD, RDMS, Assistant Professor, Department of Emergency Medicine, University of Maryland School of Medicine
Article: Bloc S, Mercadal L, Garnier T, et al. Evaluation of a new disinfection method for ultrasound probes used for regional anesthesia.J Ultrasound Med. 2011;30:785-788.
Objectives: To evaluate the efficacy of a probe disinfection method using ultraviolet-C (UV-C) light.
Methods: A 3-step disinfection protocol was created: first, a dry wipe was used to remove visible gel; second, a moist antiseptic wipe was used; finally, the probe was exposed to UV-C light in a chamber for 90 seconds. In the first phase of the study, probes were exposed to gel inoculated with Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis for 5-7 minutes. The probes were then disinfected using the new protocol. Culture swabs were collected before and after disinfection. In the second phase, disinfected probes were used to place nerve blocks. No probe covers were used. Culture swabs were collected before and after the blocks were performed. Culture swabs were inoculated on chocolate agar plates and incubated for 48 hours. Cultures were considered sterile if there were < 10 colony forming units (CFU).
Results: After exposure to the infected gel, all probe cultures grew more than > 150 CFU. After disinfection, all were sterile. Over the 50 nerve blocks performed, cultures were sterile before and after the block.
Discussion: UV-C light has the potential to revolutionize probe disinfection in the emergency department. UV-C light provides high-level disinfection and could replace chemical bath disinfection and its vapor containment requirements. The superior speed of UV-C light vs. chemical baths means that the probe is out of service for a shorter period of time and can be disinfected on-demand just before a planned procedure to ensure its sterility. This eliminates the problem of how to maintain probe sterility after a chemical bath while waiting for its next use. As the authors note, their study did not evaluate viral disinfection or the long term effects of UV-C light on the probe’s matching layer. If these issues can be addressed with further study, then disinfection using UV-C light will be an excellent match for the rapid pace of the emergency department.
Reviewer: Seth Oskie, MD, Harbor-UCLA Medical Center
Article: Ünlüer EE, Yavasi O, Eroglu O, Yilmaz C, Akarca FK. Ultrasonography by emergency medicine and radiology residents for the diagnosis of small bowel obstruction.Eur J Emerg Med. 2010;17(5):260-264.
Objective: This study examines the accuracy of emergency medicine and radiology resident performed bedside ultrasound for the diagnosis of mechanical small bowel obstruction (SBO).
Methods: Prospective study that included a convenience sample of emergency department patients over the age of 18-years-old with suspected mechanical SBO based on symptoms and clinical findings of abdominal pain, distention, vomiting and decreased frequency of bowel movements. All patients participating in the study underwent a 5 minute protocol for bedside ultrasound to detect the presence of SBO by one of 4 third-year Emergency Medicine (EM) resident investigators who underwent 3 hours of didactic and 3 hours of hands-on training with a radiologist. All patients in the study had a second abdominal ultrasound study performed in the radiology department by third-year radiology residents with experience in this application. The sonographers were not blind to the patent’s clinical status. Confirmatory studies including abdominal radiography and abdominal computed tomography were done after ultrasound protocols.
Bedside ultrasound was considered to be positive when at least two of the three main mechanical small bowel obstruction findings were present: (1) small bowel loops greater than 25 mm in jejunum or greater than 15 mm in ileum over a length of more than three loops, (2) increased peristalsis, and (3) a collapsed colonic lumen. Jejunal dilated small bowel was differentiated from ilium by the sonographic presence of numerous and prominent valvulae folds in the bowel wall lumen. The study gold standard for the presence of mechanical SBO was a surgical pathology diagnosis. Surgical confirmation was necessary to be considered a true positive in this study. The absence of SBO was defined by a negative CT, benign clinical course at telephone followup one month after presentation or negative surgical findings. Patients who refused surgery, lost to followup or pregnant were excluded.
Results: The study enrolled 174 patients. Emergency medicine resident performed bedside ultrasound (EM BUS) was positive in 90 patients. Eighty-four of these positive EM BUS studies were confirmed by post operative surgical diagnosis of mechanical SBO (true positives). In 78 cases, EM BUS was negative, and 76 of these patients had benign clinical courses. However, two went on to be surgically diagnosed with mechanical SBO (false negatives). Six patients were excluded from the study. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio (95% CI included) for EM BUS were 97.7 (94.5–100), 92.7 (87.0–98.3), 93.3 (88.2–98.5), 97.4 (93.9–100), and 13.4% (6.2–28.9), respectively. Sensitivity, specificity, positive predictive value, and negative predictive value for radiology resident performed ultrasound were 88.4 (81.6–95.2), 100, 100, and 89.1% (82.8–95.5), respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio for plain abdominal radiography were 88.4 (81.6 - 95.1), 57.5 (46.6-68.3), 69.1 (60.4-77.7), 82.1 (72.1-92.1), and 2 (1.6-2.7), respectively. The diagnostic accuracy of BUS and RUS were not statistically different from each other (k = 0.81). The presence of dilated small bowel loops was the most sensitive (94%) and specific (94%) sonographic finding for SBO.
Discussion: The study suggests that emergency medicine residents familiar with bedside ultrasound can learn to accurately identify sonographic findings of mechanical SBO in the appropriate clinical context. The additional diagnostic benefit of bedside ultrasound beyond clinical suspicion alone remains unclear. The findings reported encourage further research into the potential role of bedside ultrasound in emergency department management of mechanical small bowel obstruction.
Reviewers: Laura Diegelmann, MD, Clinical Instructor, University of Maryland School of Medicine, Emergency Ultrasound Fellow; and Sarah Sommerkamp, MD, RDMS, Instructor, University of Maryland School of Medicine
Article: Lyon M, Shiver SA, Walton P. M-mode ultrasound for the detection of pneumothorax during helicopter transport. Am J Emerg Med. 2011 Oct 25. [Epub ahead of print]
Objective: The objective of this study was to evaluate the utility of M-mode US as an adjunct to the sliding lung sign (SLS) to detect pneumothorax during helicopter transport.
Methods: This prospective observational trial was conducted at a large tertiary facility with aeromedical transport using an IV pressure bag model to simulate lung pleural interface. Sixteen M-mode images obtained on the ground with (5) and without (5) rotation and at level flight (6) in addition to 10 M-mode human images were used in the study. In each helicopter scenario, the images were both of normal lungs (9) and pneumothorax (7) with the human images also being of normal lung (5) and pneumothorax (5). Four US-credentialed emergency physicians reviewed all 26 images without prior tutorial or instruction.
Results: Altogether, 104 M-mode images were reviewed and each image was correctly identified. The sensitivity and specificity in the clinical setting was 100%. The helicopter rotors created motion artifact greatest at level flight; however, it did not affect the reviewer’s ability to correctly identify the images.
Discussion: Ultrasound is a valuable tool in the prehospital setting, especially during helicopter transport, where stethoscopes lose utility due to noise artifact. Correct identification of a pneumothorax is essential at altitude due to changes in lung volume and the potential consequences. M-mode US imaging can successfully be used to detect the SLS during helicopter transport.
Reviewers: Sarah Sommerkamp, MD, RDMS, Instructor, University of Maryland School of Medicine; and Laura Diegelmann, MD, Clinical Instructor, University of Maryland School of Medicine, Emergency Ultrasound Fellow
Article: van Randen A, Laméris W, van Es HW, et al. A comparison of the accuracy of ultrasound and computed tomography in common diagnoses causing acute abdominal pain.Eur Radiol. 2011;21(7):1535-1545.
Objective: This is a direct comparison of ultrasound imaging to CT scans for evaluating abdominal pain.
Methods: Six large hospitals collaborated in this study of 1,021 patients. They took a consecutive sample of patients presenting with 2 hours to 5 days of abdominal pain. The patients received both an ultrasound and a CT (IV contrast no PO contrast). The ultrasound was completed and read by either a radiology resident or an attending physician and finalized prior to CT completion and interpretation. A group convened 6 months after the trial to assign final diagnosis upon review of both studies and of hospital and follow-up records. Information about reader experience and patient characteristics were collected.
Results: The study population had a large number of positive scans, including appendicitis (28%), diverticulitis (12%), cholecystitis (5%), and other diagnoses. CT was found to have significantly better sensitivity than ultrasound in the detection of appendicitis (94% versus 76%) and diverticulitis (81% versus 61%). Positive predictive values were comparable. CT and ultrasound were equivalent for the diagnosis of cholecystitis (73%). Operator experience did not have a significant effect on the sensitivity of ultrasound. Obesity did not have a significant effect on missed diagnosis. Missed diagnosis was significantly greater, however, in studies noted to be inadequate.
Discussion: The goal of the study, a head-to-head comparison of CT and ultrasound, was achieved. The study found the sensitivity of CT better than ultrasound for appendicitis and diverticulitis. The sensitivity was equivalent for cholecystitis and small bowel obstruction. No subgroup analyses were statistically significant. This is surprisingly different from commonly held beliefs and prior studies. They reviewed some limitations of the study, including unsupervised residents reading ultrasounds, that could potentially lead to lower sensitivities and the expert panel defining final diagnosis based on the studies being compared. With the recent focus on the effects of ionizing radiation, the authors sought to compare ultrasound to CT. Their findings show that CT is better for diagnosing most abdominal pathology but also that ultrasound is capable of diagnosing many intra-abdominal conditions with sensitivities in the 60th and 70th percentages. This suggests a possible paradigm shift, ordering an ultrasound first followed by CT if initial testing is negative.