Emergency Ultrasound Section Newsletter - December 2012
|Announcements - Emergency Ultrasound Section Newsletter, December 2012|
|From the Chair - Emergency Ultrasound Section Newsletter, December 2012|
|In the News - Emergency Ultrasound Section Newsletter, December 2012|
|Case Report: To See or Not to See? - Emergency Ultrasound Section Newsletter, December 2012|
|Social Media in EM US Today - Emergency Ultrasound Section Newsletter, December 2012|
|Pediatric Hip Tips - Emergency Ultrasound Section Newsletter, December 2012|
|Workflow Solutions: Top 10 Reasons Everyone Needs One [Part 1 of 2] - Emergency Ultrasound Section Newsletter, December 2012|
|Ask the Expert - Emergency Ultrasound Section Newsletter, December 2012|
|Updates from the Ten Institution New York City US Grand Rounds - Emergency Ultrasound Section Newsletter, December 2012|
|Journal Watch - Emergency Ultrasound Section Newsletter, December 2012|
|Annual Section Meeting Minutes & Subcommittee Reports - Emergency Ultrasound Section Newsletter, December 2012|
Announcements - Emergency Ultrasound Section Newsletter, December 2012
- EMF Mindray 20K Grant Applications Due January 11th, 2013
- ACEP US Section 10K Grants Letter of Intent Due February 13th, 2013
- Many thanks to all section editors! If you want to contribute to the next newsletter, please email John Bailitz, MD, FACEP
From the Chair - Emergency Ultrasound Section Newsletter, December 2012
Rajesh Geria MD RDMS FACEP
I’d like to begin the year by first thanking everyone for giving me the opportunity to represent the section this year. And many more thanks to outgoing chair Dr. Mike Stone for all of his dedication, creativity, and leadership as chair last year!
Despite being in one of the biggest rooms available, our annual section meeting in Denver was once again standing room only. Congratulations to Dr. Vicki Noble on her award recognizing her many contributions to emergency ultrasound. If you were not able to attend, then please take a few moments to download and review the Annual Meeting Minutes and Subsection Reports.
There are several high priority issues that we will need to work together on this upcoming year. Many of us continue to face denials and bundling of ultrasound codes into the E&M codes by CMS and third party payors. I plan to create a task force to create an official branding of point of care ultrasound in the acute care setting. We will seek support from allies at AIUM and ideally work together on a joint POCS reimbursement consensus statement.
Middleware image archival and data management solutions continue to gain momentum. However, many EDs, especially in the community setting, are still struggling to implement this technology. I plan to work closely with the industry communications subcommittee to develop tools that will not only help our colleagues justify the purchase of these workflow solutions, but also navigate through the daunting task of implementation with local IT. If anyone is interested in helping with this project please email the chair, Mark Byrne. See Mark’s great Workflow Solutions Part I below.
The accreditation subcommittee was created to help ensure ultrasound programs adhere to a minimum standard of safety and quality as demanded by our patients as well as public and private sector payors. In 2010, the Clinical Ultrasound Accreditation Program was developed in order to assist programs in developing the infrastructure necessary to meet ACEP guidelines. The committee is now submitting a final document to the ACEP Board for approval. The plan will be to roll out to test sites this year. We are going to need application reviewers so if anyone is interested in helping with this project please email the subcommittee chair, Mike Mallin.
These are just a few of many projects that I am excited to collaborate with everyone on this year. If you would like to get involved, then please send me an email. Let’s get started!
In the News - Emergency Ultrasound Section Newsletter, December 2012
Case Report: To See or Not to See? - Emergency Ultrasound Section Newsletter, December 2012
Amanda Medoro MD
Kevin A. O’Toole MD FACEP
Meghan K. Herbst MD
Chief Complaint: “I can’t see out of my left eye!”
1. What is the pathology shown on the clip below?
2. What is the sensitivity of bedside ultrasound for detecting the pathology shown?
3. What are the indications for performing a bedside ocular ultrasound in the emergency department?
A 62-year-old otherwise healthy female presented with a chief complaint of vision loss in her left eye. Prior to losing her vision, she saw black spots in her left eye. Vision in her right eye was not affected. On exam, her pupils were equal and reactive to light. Tonometry pressures were both less than 15. Her right eye vision was 20/25, and her left eye vision was completely absent. There were otherwise no cranial nerve or focal neurologic deficits.
After performing a bedside ultrasound, ophthalmology was immediately consulted and she regained her vision following acute intervention.
The Role of Emergency Ultrasound in the Patient with Vision Change:
The eye is ideal for ultrasound imaging because its vitreous humor is anechoic and provides an excellent window for viewing posterior ocular structures. Acute vision loss may stem from central or peripheral pathologies, and bedside ultrasound can help emergency physicians rapidly rule in or rule out retinal detachment, vitreous detachment, or vitreous hemorrhage.
To perform the exam, a Tegaderm is placed over the closed lid of the affected eye. A generous amount of gel is then applied over the Tegaderm. Using a high-frequency linear probe, the eye is visualized in sagittal and transverse planes. It is helpful to have the patient move his/her eyes in all directions while viewing, as a retinal detachment, vitreous detachment, or vitreous hemorrhage have differing degrees of mobility that will aid in the correct identification of the pathology.
Answers to Questions:
- Figure 1 below shows a still ultrasound image of the normal eye. The top of the screen represents the anterior surface of the eye where you can see the anterior chamber and lens, and towards the bottom of the screen is the posterior surface of the eye (where the retina is the innermost lining). The optic nerve looks like a hypoechoic shadow extending posteriorly from this surface. The papilla is where the optic nerve leaves the retina, and an important region to look at when differentiating posterior ocular pathology. On the clip that there are two wavy hyperechoic structures that appear to be anchored at the papilla. These represent a complete retinal detachment, where both ends of the retina (“retinal flaps”) are detached from the choroidal layer of the eye, but fixed at the papilla. Notice that with eye movement, there is some movement of the retinal detachment.
- Bedside ultrasound performed by EP has been shown to be very sensitive and moderately specific for retinal detachment (RD). A recent prospective study by Jang et al (1) looked at EP-performed ocular ultrasound for RD on 48 patients presenting to the ED with acute vision change, with ophthalmologist diagnoses as the gold standard. 38% had RD diagnosed by an ophthalmologist. Sensitivity in this study was 100%, and specificity 83%. An earlier prospective observational study by Blaivas et al (2) looked at 61 patients with eye trauma or visual changes and found a sensitivity of 100% and specificity of over 97% for ocular pathology, including RD.
- Indications for ocular ultrasound in the ED:
- Change in vision: Look for retinal detachment, vitreous detachment, and vitreous hemorrhage using bedside ultrasound.
- Trauma: In the setting of trauma it is often difficult to examine the eye due to significant soft tissue swelling. Bedside ultrasound can be used to evaluate pupillary function, extraocular muscle function, anterior and posterior chamber hemorrhage, lens luxation, and even retrobulbar hematoma (3). Globe rupture can also be detected, but even small pressure applied by the ultrasound transducer may lead to further extrusion of ocular contents, and for this reason suspicion for globe rupture is a relative contraindication for bedside ultrasound.
- Foreign body: Intraocular foreign bodies often appear hyperechoic and contrast well with the anechoic medium of the eye.
- Suspected increased intracranial pressure: There have been several small studies correlating optic nerve sheath diameter with intracranial pressure (4). Larger studies are still needed to better define test characteristics and criteria.
1.Yoonessi R, Hussain A, Jang TB. Bedside ocular ultrasound for the detection of retinal detachment in the emergency department. Acad Emerg Med. 2010; 17:913-917.
2. Blaivas M, Theodoro D, Sierzenski P. A study of bedside ocular ultrasonography in the emergency department. Acad Emerg Med. 2002. 9(8): 791-799.
3. Harries A, Shah S, Teismann N, et al. Ultrasound assessment of extraocular movements and pupillary light reflex in ocular trauma. Am J Emerg Med. 2010; 28: 956-959.
4. Kimberly HH, Shah S, Maril K, et al. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med. 2008. 15(2): 201-204.
Social Media in EM US Today - Emergency Ultrasound Section Newsletter, December 2012
Viveta Lobo MD
Laleh Gharahbaghian MD FACEP
In a realm where the access to free education is becoming the mantra and expectation across learners, the emergence of social media is fast gaining popularity. A quick Google search, defines social media as, “a media for social interaction, using highly accessible and scalable publishing techniques.” As a physician, educator, and learner in an academic institution, this modality of education promises to bestow unending means. Being able to have a presence 24/7 and allow access to learning at the convenience of learners is almost too good to be true. It is no wonder why higher education across the globe, and now even primary education has adopted social media as the forefront modality to reach and connect with learners.
The medical field is no exception. As we begin to recruit the most “tech savvy” group of students in our medical schools and residencies, the expectation to continue learning “on the cloud” is ongoing. Tweeting anatomy pearls, sharing Dropbox files on physiology notes, and joining Google hangouts for journal clubs - is quickly becoming the theme for most educational sites. And why shouldn't it be? Being able to remotely participate in learning and connect with peers anywhere in the world, from your home, office, or emergency department, can only lead to extraordinary things.
Emergency medicine has rightly developed a reputation for being progressive and innovative. Emergency ultrasound lends itself to be the perfect subset to thrive with social media, and it has taken off! Being able to upload ultrasound clips online and teach anatomy, highlight pathology, and reward “great saves” for not just your own institution, but the entire ultrasound community goes way beyond the classroom. Websites, Blogs, Podcasts, Facebook group pages - whatever your fancy, it’s there - and it’s free. Our goal, has always been to try, learn, fail, succeed - but at the end, share. There is no better way to share than by using social media. Being able to connect all across the globe with other EM US enthusiasts, interact and discuss various topics and strategies has only helped us all do better, within our sub specialty and beyond. So don't be skeptical, and give it a try! We’ve listed some of our favorite FREE picks, in no particular order, to help you get started…. There are plenty more out there….Until next time - see you on the cloud!
Sonoguide: Ultrasound Guide for Emergency Physicians – offers a description of each bedside US application, ultrasound images and videos – all to train and review US utility for aiding diagnosis, management and treatment by Dr, Beatrice Hoffman
SonoWorld – a comprehensive site that includes hundreds of lectures, cases, videos, and articles that includes basic bedside ultrasound applications, but goes beyond that to satisfy the needs of all US enthusiasts.
Emergency Ultrasonography – a comprehensive website geared to emergency physicians that contains many lectures, cases, and educational content that can be used by residencies for the didactic portion of ultrasound education by Dr, Geoff Hayden.
SAEM Ultrasound Narrated Lectures – just as it states, a library of lectures on bedside ultrasound with a link to a free pdf of ultrasound guides on that same site.
Sinai EM Ultrasound – a complete site of free online lectures, cases, research articles, and news on bedside ultrasound topics by Dr. Bret Nelson.
Society of US in Medical Education – learning modules and curriculum databases with a long lecture list on all basic bedside ultrasound topics that allows the learner to control the pace of the lecture.
Vanderbilt’s EM Ultrasound – a collection of brief lectures on each bedside ultrasound topic in a well-organized way with quizzes that can be taken to test your knowledge by Dr. Jim Fiechtl
ICU Sonography lectures for Echo/IVC and more by: Beth Israel, Stanford, and Yale
European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB)– a free and comprehensive European full textbook found online for free on each ultrasound application
Partners In Health Textbook for Ultrasound in Resource Limited Areas – by Drs. Sachita Shah, Dan Price, Gene Bukhman, Sachin Shah, Emily Wroe
iBook for the iPAD – a new textbook brought from the Ultrasound Podcast guys and written by many US educators sure to bring a new concept to the world of online education - The iBook and all it’s glory: http://www.youtube.com/watch?v=mB7_omzi8Cc
Ultrasound Podcast – one of the best, and funniest ways of teaching ultrasound to all learners. This podcast discusses all ultrasound applications, keeps it easy, and makes it engaging by Drs. Mike Mallin and Matt Dawson, with Stone’s side excerpts from Dr. Mike Stone.
UC Irvine’s iTunes lecture series – an excellent and comprehensive lecture podcast library of all bedside ultrasound applications by Dr. Chris Fox.
Soundbytes – a collection of free lectures for all bedside ultrasound applications in a concise and free format by Dr. Phil Perera.
SonoSpot: Topics in Bedside Ultrasound – a blog that discusses tutorials, cases, tips/tricks, research, links/sites, and people in the ultrasound community by Dr. Laleh Gharahbaghian (yes, shameless plug here).
Bedside Ultrasound – Ultrasound teaching updates with tips/tricks and brief video lectures of the hot topics in bedside ultrasound and interviews with US enthusiasts by Dr. Mike Stone.
Highland Hospital ED Ultrasound - a collection of blog posts that focus on procedural US guided applications in addition to the basic US application by Dr. Arun Nagdev and Andrew Herring
Sonocloud – the ultimate library of ultrasound clips – an amazing free image upload and download site where you can find any ultrasound clip you need to review, place in your lecture, or use to learn and teach others by Drs Mike Mallin, Matt Dawson, and Mike Stone.
Vimeo: US in Emergency Medicine and Critical Care group – a large collection of ultrasound clips for your viewing pleasure of pathologies, normal anatomy, and more by the HQMedEd (high quality medical education) team at Hennepin County Medical Center
Free Smartphone Apps:
1-Minute Ultrasound – by the Ultrasound Podcast guys for your iPhone, with 1 minute reviews of all applications in an easy to learn way.
SonoAccess – a list of lectures and images in a smartphone app.
AIUM_Ultrasound, AllUltrasound, Bedsidesono, BMUS_Ultrasound, ECCUltrasound, EchoCardiac, EDUltrasound, EDultrasoundQA, EM Res, GeriaSonoMD, SAEMAEUS, Sinai EM Ultrasound, SonoSpot, SUSME, UltrasoundFirst, UltrasoundMeme, UltrasoundPod, Ultrasound Training, Ultrasound Quarterly, USEDCDN
Pediatric Hip Tips - Emergency Ultrasound Section Newsletter, December 2012
Samuel Lam MD FACEP
Russ Horowitz MD
Limping, hip pain, and refusal to bear weight are common pediatric complaints in the emergency department. The differential diagnosis includes muscle strain, slipped capital femoral epiphysis, Legg Calve Perthes disease, fracture, osteomyolitis, neoplasm, juvenile rheumatoid arthritis, transient (toxic) synovitis, and septic arthritis. Identification of a hip effusion using bedside ultrasound may help to narrow this differential and direct care. Ultrasound can also be used to guide bedside joint aspiration by the emergency physician.
Imaging is done via the anterior approach. The patient is placed in a supine position with the hips in a neutral position. A high frequency linear probe is then placed in the sagittal plane parallel to the femoral neck. The femoral neck is identified, along with the overlying capsule and the iliopsoas muscle. The capsule is then measured from the anterior portion of the femoral neck to the anterior portion of the capsule.
An abnormal capsule is greater than 5 mm or is more than 2 mm wider than the contralateral (normal/asymptomatic) side. In addition, an effusion will change the capsule’s appearance from concave to convex.
There have been 2 case series and one prospective observational study published on the performance of point-of-care hip ultrasound by emergency physicians.1-3 In the Veira study, bedside ultrasonography had a sensitivity of 80% and a specificity of 98% compared to radiology department study results.1 Though specific in diagnosing joint effusion, bedside ultrasound cannot reliably distinguish between benign e.g. transient synovitis and potentially serious causes e.g. septic arthritis.4 It is best utilized when combined with other studies such as serum ESR and CRP, plain radiography, and culture of synovial aspirate. Nevertheless, authors seem to agree that septic arthritis is unlikely to be present if joint effusion is absent.
All figures courtesy of Jennifer R. Marin MD
1. Veira RL, Levy, JA. Bedside ultrasound to identify hip effusions in pediatric patients. Ann Emerg Med. 2010; 55: 284-89.
2. Tsung JW, Blaivas M. Emergency department diagnosis of pediatric hip effusion and guided arthrocentesis using point-of-care ultrasound. J Emerg Med. 2008; 35: 393-99.
3. Shavit I, Eidelman M, Galbraith R. Sonography of the hip joint by the emergency physician: its role in the evaluation of children presenting with acute limp. Ped Emerg Care. 2006; 22: 570-73.
4. Zamzam MM. The role of ultrasound in differentiating septic arthritis from transient synovitis of the hip in children. J Pediatr Orthop B. 2006; 15: 418-22.
Workflow Solutions: Top 10 Reasons Everyone Needs One [Part 1 of 2] - Emergency Ultrasound Section Newsletter, December 2012
Mark W. Byrne MD
By now, most people in emergency ultrasound have either heard of or thought about getting a commercial workflow solution product. But many still don’t understand all that they can do, thinking of them as mostly image archival tools. Surprisingly, even some who own these products aren’t using them to their full potential.
In this 2-part series, I wanted to highlight some of the best features of these products and the most compelling reasons why you should get one.
1. Wireless Upload
If you’re still downloading studies to DVD or USB and then transferring to a hard drive, you’re spending time on something that can be set up to occur automatically and seamlessly as soon as you complete your exam. And these products all have back-up functionality so you don’t have to go the extra step of manually backing up all your DVDs and hard-drives.
2. Paperless Worksheets
Interpretations can now be entered directly onto your ultrasound machine at the point-of-care and subsequently transferred along with the images wirelessly to your ultrasound database. No longer will you have to juggle individual paper worksheets, worry about lost binders, or waste your time entering what’s already on paper into a separate electronic database or the EMR.
3. Push to PACS
Your consultants are used to viewing images within the Radiology PACS system. Many sites want the ability to send completed studies to the PACS so that emergency ultrasound images can be found in a familiar location. Although this is likely to change as workflow solution products become better integrated with the EMR -- a whole other topic unto itself.
4. Automating QA feedback
You just spent the time filling out a QA worksheet, either on paper or within your own custom electronic database. So why repeat the whole process by manually typing an email every time you want to send this feedback to your sonographers? These programs automate the process for generating and sending QA feedback reports from the information you’ve already entered into your ultrasound database.
5. Track Credentialing
Easily track the credentialing status of your residents and staff physicians. Set up the software to automatically send periodic progress reports to you and your sonographers. Or export the data to standard Excel spreadsheets if you’d like. You can even follow scan accuracy statistics for individual users and identify those scan types that may need improvement for your sonographers.
To be continued…
Watch for Part 2, where we’ll cover automated removal of patient identifiers when exporting images and clips, separation of educational from diagnostic studies within your exam database, tagging studies of interest to facilitate teaching and research, automated generation and transfer of billing reports, and the ability to view studies on your iOS mobile devices!
Ask the Expert - Emergency Ultrasound Section Newsletter, December 2012
Robert M. Bramante MD RDMS
This edition’s featured expert is:
J Matthew Fields MD
Director, Ultrasound Fellowship
Thomas Jefferson University Hospital
“How do you use ultrasound in your evaluation of the IVC and what methods are most accurate or most helpful in the ongoing resuscitation of the critical patient?”
Personally I feel IVC ultrasound should be performed in all critically ill patients. It provides diagnostic information that can help define the etiology of shock and significantly change management. I still remember the first time IVC ultrasound significantly changed my management of a difficult to examine, obese patient. The patient was hypotensive and in respiratory distress initially thought to have sepsis and pneumonia. Ultrasound showed his IVC was actually plethoric and echo revealed a significant pericardial effusion and tamponade. Since then I have made IVC ultrasound a routine part of my evaluation.
The IVC is a highly compliant vessel that traverses the liver reflecting right atrial pressure. In low pressure states the IVC is small and tends to collapse during inspiration due to the negative intrathoracic pressure generated by by chest wall expansion. In high pressure states the IVC becomes large with little to no collapse.
The Small IVC [<2.5cm , >50% collapse]
A small, highly collapsible IVC is almost always indicative of a hypovolemic state in critically ill patients. Studies have suggested that when there is 50% or more collapse the patient will respond to fluids. These numbers are guidelines and smaller IVCs may be normal in some patients with smaller body habitus.
The Large IVC [>2.5cm, <50% collapse]
A large IVC is more difficult to interpret in a critically ill patient. It may be due to volume overload, in which case fluids should be avoided. Alternatively, a large IVC may be due to obstruction (valvular disease, pulmonary hypertension, tension pneumothorax, cardiac tamponade), which may require higher filling pressures to maintain cardiac output. A large IVC alone should not determine fluid needs, but should prompt the clinician to further investigate with cardiac and thoracic ultrasound for the underlying cause.
The Middle of the Road IVC
A mid-sized or mixed picture IVC with collapse of 40% in one respiratory cycle and 60% in the next is hard to interpret. In these cases I look for other indicators such as hepatic vein dilation, RV size and filling, LV function and EF. Serial examination after fluid bolus can be useful. If uncertain I fall back on other clinical parameters to help guide fluid resuscitation.
Subxiphoid is the most common approach, but in cases of bowel gas obstruction, abdominal dressing or a protuberant abdomen the alternative intercostal approach can be performed in the mid to anterior axillary line. Before measuring I scan longitudinally and transversely through the IVC to determine if there are any anatomic strictures or extrinsic masses that would compromise IVC assessment. Most of the literature describes measuring below the entry of the hepatic veins which is typically 1-3 cm below the caval-atrial junction. I recommend watching the IVC over a few respiratory cycles and visually estimating the collapse. Visual estimation has similar reliability to measurements. I have personally found M-mode measurements are difficult for novices especially when the machine does not permit simultaneous live M-mode and B-mode display. In video review of my residents I often see a B-mode clip of an IVC that is collapsing 50% and then get an M-mode still which shows 100% collapse. This is often due to cylinder tangential effect, which occurs when the sampling beam moves from the midline of the vessel towards the edge (either due to probe movement or patient movement) leading to overestimation of collapse. Another common error occurs if the hepatic or portal vein (or even aorta when using the intercostal approach) also crosses the M-mode sampling beam and the operator accidentally measures the wrong vessel. Visual estimation avoids these errors and is simpler and quicker.
Use of IVC ultrasound in mechanically ventilated patients is a bit more challenging and depends on whether the patient is spontaneously breathing or not. In the non-spontaneous breather, mechanical insufflation leads to a greater intrathoracic than extrathoracic pressure and leads to an increase in IVC diameter. One study by Feissel et al found that if the tidal volume is set to 8-10ml/kg a delta IVC (dIVC) of >12% predicted a patient that would be fluid responsive. Another similar study by Barbier et al used a tidal volume of 8.5ml/kg and found dIVC of 18% to be predictive. Personally, changing ventilator settings and performing IVC ultrasound is a bit cumbersome in the ED and I make it more simple. If the IVC is small and the patient is hypotensive I think fluids, fluids, fluids with serial IVC assessments. If the IVC is large and the patient is hypotensive with good oxygenation, I still give a fluid challenge, but am quicker to move onto pressors.
The IVC can be reassessed after fluid boluses to assess change in collapse and diameter. I find that I trust IVC measurements more than its counterpart the CVP monitor. CVP monitors, despite being invasive, assume appropriate placement and calibration. They are frequently erratic and wrong. In contrast I know exactly what I am looking at when I perform IVC ultrasound. If a CVP monitor is placed I use IVC ultrasound to double check its readings.
In summary, when correctly used IVC ultrasound is extremely helpful in managing the critically ill. Below are some studies that I find have been useful in shaping my understanding of the IVC:
1. Jones AE, Tayal VS, Sullivan DM, et al. Randomized, controlled trial of immediate versus delayed goal-directed ultrasound to identify the cause of nontraumatic hypotension in emergency department patients. Crit Care Med. 2004 Aug;32(8):1703-8.
2. Ferrada P, Anand RJ, Whelan J, et al. Qualitative assessment of the inferior vena cava: useful tool for the evaluation of fluid status in critically ill patients. Am Surg. 2012 Apr;78(4):468-70.
3. Nagdev AD, Merchant RC, Tirado-Gonzalez A, et al. Emergency department bedside ultrasonographic measurement of the caval index for noninvasive determination of low central venous pressure. Ann Emerg Med. 2010 Mar;55(3):290-5. Epub 2009 Jun 25.
4. Perera P, Mailhot T, Riley D, et al. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am. 2010 Feb;28(1):29-56, vii.
5. Weekes AJ, Tassone HM, Babcock A, et al. Comparison of serial qualitative and quantitative assessments of caval index and left ventricular systolic function during early fluid resuscitation of hypotensive emergency department patients. Acad Emerg Med. 2011 Sep;18(9):912-21
6. Haydar SA, Moore ET, Higgins GL 3rd, et al. Effect of Bedside Ultrasonography on the Certainty of Physician Clinical Decisionmaking for Septic Patients in the Emergency Department. Ann Emerg Med. 2012 May 23.
1. Jue J, Chung W, Schiller NB. Does inferior vena cava size predict right atrial pressures in patients receiving mechanical ventilation? J Am Soc Echocardiogr. 1992 Nov-Dec;5(6):613-9.
2. Feissel M, Michard F, Faller JP, et al. The respiratory variation in inferior vena cava diameter as a guide to fluid therapy. Intens Care Med. 2004 Sep;30(9):1834-7.
3. Barbier C, Loubières Y, Schmit C, et al. Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients. Intens Care Med. 2004 Sep;30(9):1740-6. Epub 2004 Mar 18.
1. Sefidbakht S, Assadsangabi R, Abbasi HR, et al. Sonographic measurement of the inferior vena cava as a predictor of shock in trauma patients. Emerg Radiol. 2007 Jul;14(3):181-5. Epub 2007 Jun 1.
2. Yanagawa Y, Sakamoto T, Okada Y. Hypovolemic shock evaluated by sonographic measurement of the inferior vena cava during resuscitation in trauma patients. J Trauma. 2007 Dec;63(6):1245-8; discussion 1248.
3. Akilli B, Bayir A, Kara F, Ak A, et al. Inferior vena cava diameter as a marker of early hemorrhagic shock: a comparative study. Ulus Travma Acil Cerrahi Derg. 2010 Mar;16(2):113-8.
1. Kosiak W, Swieton D, Piskunowicz M. Sonographic inferior vena cava/aorta diameter index, a new approach to the body fluid status assessment in children and young adults in emergency ultrasound--preliminary study. Am J Emerg Med. 2008 Mar;26(3):320-5.
2. Chen L, Hsiao A, Langhan M, et al. Use of bedside ultrasound to assess degree of dehydration in children with gastroenteritis. Acad Emerg Med. 2010 Oct;17(10):1042-7.
3. Levine AC, Shah SP, Umulisa I, et al. Ultrasound assessment of severe dehydration in children with diarrhea and vomiting. Acad Emerg Med. 2010 Oct;17(10):1035-41
1. Wallace DJ, Allison M, Stone MB. Inferior vena cava percentage collapse during respiration is affected by the sampling location: an ultrasound study in healthy volunteers. Acad Emerg Med. 2010 Jan;17(1):96-9. Epub 2009 Dec 9.
2. Fields JM, Lee PA, Jenq KY, et al. The interrater reliability of inferior vena cava ultrasound by bedside clinician sonographers in emergency department patients. Acad Emerg Med. 2011 Jan;18(1):98-101
3. Kimura BJ, Dalugdugan R, Gilcrease GW 3rd, et al. The effect of breathing manner on inferior vena caval diameter. Eur J Echocardiogr. 2011 Feb;12(2):120-3. Epub 2010 Oct 27.
4. Saul T, Lewiss RE, Langsfeld A, et al. Inter-rater reliability of sonographic measurements of the inferior vena cava. J Emerg Med. 2012 May;42(5):600-5. Epub 2012 Jan 12.
1. Cheriex EC, Leunissen KM, Janssen JH, et al. Echography of the inferior vena cava is a simple and reliable tool for estimation of 'dry weight' in haemodialysis patients. Nephrol Dial Transplant. 1989;4(6):563-8.
2. Kircher BJ, Himelman RB, Schiller NB. Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava. Am J Cardiol. 1990 Aug 15;66(4):493-6.
3. Lyon M, Blaivas M, Brannam L. Sonographic measurement of the inferior vena cava as a marker of blood loss. Am J Emerg Med. 2005 Jan;23(1):45-50.
4. Brennan JM, Ronan A, Goonewardena S, et al. Handcarried ultrasound measurement of the inferior vena cava for assessment of intravascular volume status in the outpatient hemodialysis clinic. Clin J Am Soc Nephrol. 2006 Jul;1(4):749-53. Epub 2006 May 24.
5. Carr BG, Dean AJ, Everett WW, et al. Intensivist bedside ultrasound (INBU) for volume assessment in the intensive care unit: a pilot study. J Trauma. 2007 Sep;63(3):495-500; discussion 500-2.
6. Brennan JM, Blair JE, Goonewardena S, et al. Reappraisal of the use of inferior vena cava for estimating right atrial pressure. J Am Soc Echocardiogr. 2007 Jul;20(7):857-61.
7. Blehar DJ, Dickman E, Gaspari R. Identification of congestive heart failure via respiratory variation of inferior vena cava diameter. Am J Emerg Med. 2009 Jan;27(1):71-5.
8. Stawicki SP, Braslow BM, Panebianco NL, et al. Intensivist use of hand-carried ultrasonography to measure IVC collapsibility in estimating intravascular volume status: correlations with CVP. J Am Coll Surg. 2009 Jul;209(1):55-61
9. Moretti R, Pizzi B. Inferior vena cava distensibility as a predictor of fluid responsiveness in patients with subarachnoid hemorrhage. Neurocrit Care. 2010 Aug;13(1):3-9.
10. Resnick J, Cydulka R, Platz E, et al. Ultrasound does not detect early blood loss in healthy volunteers donating blood. J Emerg Med. 2011 Sep;41(3):270-5. Epub 2011 Mar 21.
11. De Lorenzo RA, Morris MJ, Williams JB, et al. Does a simple bedside sonographic measurement of the inferior vena cava correlate to central venous pressure? J Emerg Med. 2012 Apr;42(4):429-36. Epub 2011 Dec 22.
12. Dipti A, Soucy Z, Surana A, et al. Role of inferior vena cava diameter in assessment of volume status: a meta-analysis. Am J Emerg Med. 2012 Jan 3.
Updates from the Ten Institution New York City US Grand Rounds - Emergency Ultrasound Section Newsletter, December 2012
On Wednesday, September 12th, 2012 the 27th quarterly Ultrasound City-Wide Grand Rounds discussion was held at St. Luke’s-Roosevelt Hospital Center. Jerry Chirocolo MD, Emergency Ultrasound Division director at New York Methodist Hospital and the 2009-2010 ACEP Ultrasound Section chair, led a roundtable discussion on how and why to become involved in emergency ultrasound on a national level. Over 35 faculty, fellows and residents representing 10 institutions from the New York area attended.
Dr. Chirocolo outlined a variety of reasons to get involved in national ultrasound organizations. Participation in organizations, such as the American College of Emergency Physicians (ACEP), the Society for Academic Emergency Medicine (SAEM), or the American Institute of Ultrasound in Medicine (AIUM), affords opportunities to learn from others in the field of emergency ultrasound, exchange ideas and strategies, and bring knowledge and new ideas back to one’s home institution. Moreover, such involvement creates a platform for individuals to initiate dialogue and discussion on a broader level about ultrasound specifics that are important to them. National organizations also allow involvement occurring on the national level; one example that was cited was the recent debate in the ACEP ultrasound section about whether to pursue ACGME accreditation for ultrasound fellowships. Lastly, participation in national organizations can provide opportunities for leadership.
The discussion included a comprehensive list of the organizations in which faculty, fellows and residents may become involved. The ACEP ultrasound section has the largest membership (>1000) and has historically written policy for emergency medicine physicians. The Academy of Emergency Ultrasound of SAEM has a more academic organizational focus and is smaller in membership size but still influential. In contrast to these emergency medicine based organizations, AIUM is a multidisciplinary group including all specialties that use ultrasound in their clinical practice, including specialists in radiology, OB/GYN, as well as ultrasound technicians. Emergency medicine physicians are becoming increasingly involved in this group. In addition to these organizations, emergency medicine residents can elect to participate in a resident-focused group such as the Emergency Medicine Residents’ Association (EMRA).
Also debated was the value of participation in the American Registry for Diagnostic Medical Sonography (ARDMS) through its certification examinations. Many emergency physician sonologists have the Registered Diagnostic Medical Sonographer (RDMS) certification. The opinions of attendees varied with a general consensus that the RDMS is ultimately not intended for physician sonologists but involvement may serve as a stopgap until a more appropriate homegrown emergency certification is established.
Journal Watch - Emergency Ultrasound Section Newsletter, December 2012
Brian Euerle MD RDMS FACEP
Greg R. Bell MD
Article: Brooke M, Walton J, Scutt D, et al. Acquisition and interpretation of focused diagnostic ultrasound images by ultrasound-naive advanced paramedics: trialing a PHUS education program. Emerg Med J. 2012;29(4):322-326.
Reviewer: Alisa Sato MD, Emergency Ultrasound Fellow, Harbor-UCLA Medical Center
Objective: To investigate whether paramedics can acquire and interpret lung ultrasound (US) images accurately after a brief educational course.
Methods: This was a prospective observational cohort study performed through the University of Liverpool and the North West Ambulance Service NHS Trust. Ten of 36 advanced paramedics volunteered for the study and underwent 2 days of training on thoracic US. The participants were taught how to identify pleural sliding, comet tail artifacts, and a lung point using two-dimensional (2D) ultrasound imaging and how to use M-mode to identify “seashore” signs and “stratosphere” signs. After the training, the paramedics underwent a two-part examination that assessed their ability to 1) evaluate video clip images for the presence or absence of a pneumothorax and 2) obtain images of sufficient quality to identify a pneumothorax. These results were compared with those of two blinded ultrasound experts to determine overall accuracy.
Results: For part I (evaluating prerecorded lung ultrasound video clips), the paramedics assessed a total of 30 images and answered 3 questions for each image. The paramedics demonstrated accuracy similar to that of the experts in identifying a pneumothorax in M-mode clips (0.94 vs 0.93), and 2D mode clips (0.78 vs 0.76). For part II (objective structured clinical examination assessment), all advanced paramedics engaged in a direct clinical examination and were assessed by two expert sonographers, with a 100% success rate. All paramedics obtained excellent US images and interpreted them correctly.
Discussion: This study proposes that paramedics can achieve excellence in acquiring and interpreting lung US images compared with expert sonographers with 2 days of basic education and US training. This very small pilot study involved only 10 advanced paramedics, which is a limitation. It is difficult to anticipate how well the paramedics may implement these US techniques during the pressured environment of the real prehospital setting. Nonetheless, this study implies that paramedics are capable of rapidly learning thoracic US and identifying a pneumothorax, which could be life-saving in the field.
Article: Weiner SG, Sarff AR, Esener DE, et al. Single-operator ultrasound-guided intravenous line placement by emergency nurses reduces the need for physician intervention in patients with difficult-to-establish intravenous access. J Emerg Med. 2012 Oct 25. [Epub ahead of print]
Reviewer: Gregory R. Bell MD, Assistant Clinical Professor and Director of Emergency Ultrasound, University of Iowa
Objective: To determine if ultrasound-guided IV (USIV) placement by emergency nurses (EN) who undergo a brief training session can be performed with less physician intervention than standard IV line placement.
Methods: This was a prospective two-center non-blinded pilot study of 50 conveniently enrolled patients who had either a history of difficult IV placement or two failed standard IV attempts by ENs. The patients were randomly assigned to undergo either USIV placement or institutional standard-of-care (SOC) methods for difficult IV placement (not including USIV). The two centers were a large city ED (42,000 patients/year) and a medium-sized city ED with a large rural catchment (106,000 patients/year). Nurses received the same 2-hour didactic instruction and simulation training and exposure to the ultrasound machines at their respective facilities. They were taught the single-operator, out-of-plane approach. Enrollment into the study was granted when they were successfully able to cannulate using a training phantom. Nurses used their choice of needle sizes at both facilities. Patients were randomly enrolled when one of four trained researchers and a trained nurse were working in the emergency department. Parameters included total skin punctures, time from randomization, the result, and patients’ perception of pain and level of satisfaction.
Results: The cohort included 21 (42%) in the SOC arm and 29 (58%) in the USIV arm. Physicians were asked to help in 11/21 (52.4%) of SOC patients and 7/29 (24.1%) of the USIV patients (p=0.04). Other findings, not significantly different between groups, included the number of punctures, time taken for IV placement, pain perception, and patient satisfaction. Satisfaction was higher, however, in the USIV group.
Discussion: With a nominal amount of instruction, ultrasound guidance for IV placement has been an effective tool for physicians, nurses, and emergency medical technicians. This pilot study found that with 2 hours of instruction, nurses using USIV were significantly more successful and required less physician back-up than those not trained in this procedure. The authors point out that this is likely to free up physician time to tend to other matters, and it may reduce the need for central venous access. The authors point out the selection biases in the study.
Article: Sim SS, Lien WC, Chou HC, et al. Ultrasonographic lung sliding sign in confirming proper endotracheal intubation during emergency intubation. Resuscitation. 2012;83:307-312.
Reviewer: Adrea Lee MD, Emergency Ultrasound Fellow, Department of Emergency Medicine, University of Maryland School of Medicine
Objective: To assess the accuracy and timeliness of the use of ultrasound to confirm proper endotracheal tube (ETT) positioning in the trachea (and not in the mainstem bronchus) after intubations performed in the emergency department (ED).
Methods: This prospective, single-center, observational study enrolled 115 adult patients who were intubated in the ED for respiratory failure or cardiac arrest. After endotracheal intubation was confirmed by auscultation, pulse oximetry, and continuous waveform capnography, ultrasound was used to identify the presence or absence of lung sliding in the midaxillary line at the fourth or fifth intercostal space bilaterally. Bilateral lung sliding was interpreted as an ultrasonographic sign of correct placement. The primary outcome of the study was accuracy of ultrasound compared with the standard of chest radiography to confirm endotracheal and not endobronchial (ie, mainstem or one-lung intubation) placement. The secondary outcome was the timeliness of ultrasound compared with chest radiography.
Results: Of the 115 patients included in the study, 9 (7.8%) had one-lung intubations. The overall accuracy of ultrasound in confirming proper ETT placement was only 88.7%. The positive predictive value (PPV) was 95.7% in patients intubated for non-cardiac arrest reasons, but 100% in patients who were intubated for cardiac arrest. The negative predictive values (NPVs) were poor (overall 35.7%). The median operating time for ultrasound was 88 s, while that of chest radiography was 1349 s.
Discussion: This study did not find that ultrasound was equivalent to chest radiography in confirming proper positioning of the ETT after intubation. In subgroup analysis, however, the PPV of ultrasound in cardiac arrest patients was 100%, warranting further investigation, as the number in the cardiac arrest group was relatively low (n=31). In addition, the authors point out that ultrasound can be especially useful in this population, as these patients are unlikely to have chest radiography performed unless there is return of spontaneous circulation. The unilateral absence of lung sliding was insufficient to diagnose one-lung intubation, which the authors felt was in part due to the multiple anatomic causes of false negatives (malignancy, pneumothorax, effusions). The authors concluded that ultrasound is a reasonable adjunct to the standard clinical exam when assessing ETT position and that more investigation is needed to determine which populations may benefit the most from this time-saving technique.
Article: Major R, Girling S, Boyle A. Ultrasound measurement of optic nerve sheath diameter in patients with a clinical suspicion of raised intracranial pressure. Emerg Med J. 2011;28:679-681.
Reviewer: Alisa Sato, MD, Emergency Ultrasound Fellow, Harbor-UCLA Medical Center
Objective: To determine if bedside ultrasound measurement of optic nerve sheath diameter (ONSD) can accurately predict the presence or absence of raised intracranial pressure (ICP) and acute pathology in the emergency department.
Methods: This was a prospective 3-month observational study at a large urban teaching hospital in Norwich, UK, conducted from November 2007 to February 2008. After a brief training session, a group of emergency department middle grades measured the ONSD in both eyes of patients referred for a CT scan for evaluation of acute traumatic and non-traumatic pathology. A positive ONSD measurement was taken as an average of greater than 5 mm in both eyes. Two independent radiologists reviewed the CT scan images. The criteria for the diagnosis of raised ICP included one or more of the following: mass effect with midline shift of 3 mm or more, collapsed third ventricle, hydrocephalus, effacement of sulci with evidence of significant edema, or abnormal mesencephalic cisterns. The primary outcome measure was the sensitivity and specificity of ONSD measurement in identifying raised ICP evident on CT scan, and the secondary outcome measure was identifying any acute intracranial pathology evident on CT scan.
Results: Twenty-six patients were enrolled in the study; six of them had raised ICP on ONSD measurement. The radiologists confirmed signs of raised ICP on CT scans for all six of these patients. One patient had a positive CT scan without evidence of raised ICP on ONSD measurement. For the primary outcome measure (identifying increased ICP), ONSD had a specificity of 100% and a sensitivity of 86%. For the secondary outcome measure (identifying acute intracranial pathology), ONSD had a specificity of 100% and sensitivity of 60%.
Discussion: The authors concluded from this small study that, with minimal training, ONDS is a specific and sensitive measure of raised ICP and acute intracranial pathology in patients referred for CT scan in the emergency department. There were several limitations to this study, however. First, the middle grades were not blinded from the overall clinical state of their patients, which may have introduced some bias in acquiring the OSND measurement. Also, the study was very small and the patient characteristics were highly different between the trauma and non-trauma groups (for example, the non-trauma patients were much older with a worse Glasgow Coma Scale score compared with the trauma patients). Larger observational studies, possibly separating trauma from non-trauma patients, may be helpful in confirming that ONDS is indeed a helpful diagnostic tool to evaluate patients for increased ICP and acute intracranial pathology.
Article: Parri N, Crosby BJ, Glass C, et al. Ability of emergency ultrasound to detect pediatric skull fractures: a prospective, observational study. J Emerg Med. 2012 May 10 (Epub ahead of print).
Reviewer: Brian D. Euerle MD RDMS, Associate Professor, Department of Emergency Medicine, University of Maryland School of Medicine
Objective: To determine the sensitivity, specificity, and predictive values of ultrasound for identifying skull fractures in pediatric patients with minor head trauma.
Methods: This was a prospective, observational study done at a single pediatric emergency department. Children less than 18 years of age with a history of head trauma and localizing signs of trauma, such as hematoma, abrasion, or focal tenderness, who were determined to require a head CT were considered for enrollment into the study. Exclusion criteria included hemodynamic instability, neurologic deterioration, Glasgow Coma Scale score <14, open deformity, or a depressed fracture. The ultrasound assessment was performed by a study investigator who was either an emergency medicine ultrasound fellow or a pediatric emergency physician and was blinded to the clinical scenario. All study investigators had completed a 16-hour ultrasound training curriculum as well as practice cranial scanning on pediatric volunteers. Ultrasound scans were performed in the area of localized trauma using a 7.5-MHz linear probe. Entire head scanning was not done as it was felt to be impractical. Ultrasound-visible fractures were defined as cortical defects seen in two orientations not correlating with anatomic, symmetric sutures. The ultrasound study was performed before head CT whenever possible. Ultrasound findings were reported as either positive or negative for fracture and were compared with the CT scan results, which were obtained with a 40- or 64-slice scanner.
Results: Serial enrollment of eligible patients yielded 55 patients for analysis. CT scan showed 35 (63.6%) patients with cranial fractures and 20 (36.4%) without fractures. The ultrasound scan correctly identified each fracture, in the correct location with no false negatives, giving a sensitivity of 100% (95% CI, 88.2‒100). One ultrasound scan was interpreted as positive for fracture and the CT was negative, yielding a specificity of 95% (95% CI, 75‒99.9). The positive predictive value of ultrasound for cranial fractures was 97.2% (95% CI, 84.6‒99.9) and the negative predictive value was 100% (95% CI, 80.2‒100).
Discussion: In this study, cranial ultrasound had excellent accuracy in diagnosing skull fractures compared with the gold standard of CT scan. The authors commented that the ultrasound examinations were brief, painless, and relatively simple to perform by emergency physicians with varying levels of training. In an era in which physicians are increasingly mindful of the radiation exposure of patients, this is an important area for further research. It remains unclear as to how this technique might be incorporated into the overall management of head injury patients; it must be kept in mind that CT, of course, evaluates the skull as well as the underlying brain.