SonoStudies: Thoracic Ultrasound for Pulmonary Embolism #FOAMed

Thoracic ultrasound is one of the most highly changing and advancing applications of bedside ultrasound, and the research that has been published on the utility of this application for our patients cannot be ignored. It can aid (and is better than chest Xray) in pneumothorax evaluation, pleural effusion assessment (only need 15cc of fluid to see it on ultrasound!), pneumonia evaluation, and pulmonary edema assessment. See prior posts here, here and here with literature referenced to read about all of that – trust me it’s worth it!). Of course, if you add cardiac echo to your evaluation for acute pulmonary embolism, the studies suggest it helps to look for McConnells sign and RV dilation and strain (which is a bad prognostic indicator for PE). Recently, there was a case report published in J of EM of a PE-in-transit diagnosed by bedside echo, leading to expedited care and ability to know the cause of suden cardiac arrest in a patient. For a clip of what it may look like for a “mobile mass” seen in RA, click here. Another study in J of EM was done concluding that ED bedside ultrasound echo results  predicted PE adverse outcomes.

Seeing RV dilation/strain can help but are seen mainly when the patient is hemodynamically unstable. Could thoracic ultrasound identify subsegmental pulmonary embolism in patients who are not hemodynamically unstable? Interesting question and I truly hope so…

So, if that wasnt enough, now it can help with pulmonary embolism evaluation??? What?! That is great and i hope that this teaser of a study below can be repeated and found to be valid. It would be great. Now, there have been a few others, like a meta-analysis showing that thoracic ultrasound should not be ignored when suspecting PE, a review of chest ultrasound for pulmonary diseases showing its utility, and a case report and review by the Italians (who are huge researchers in thoracic ultrasound where I listen to pretty much everything they say about it).

This recent study in Annals of Thoracic Medicine, physicians in Turkey evaluate the use of bedside ultrasound for the evaluation of pulmonary embolism. The abstract is below:

“OBJECTIVES: The diagnosis of pulmonary embolism (PE) is still a problem especially at emergency units. The purpose of study was to determine the diagnostic accuracy of thoracic ultrasonography (TUS) in patients with PE.

METHODS: In this prospective study, 50 patients with suspected PE were evaluated in Department of Pulmonary Diseases of a Training and Reasearch Hospital between January 2010 and July 2011. At the begining, TUS was performed by a chest physician, subsequently for definitive diagnosis computed tomography pulmonary angiography were performed in all cases as a reference method. Other diagnostic procedures were examination of serum d-dimer levels, echocardiography, and venous doppler ultrasonography of the legs. Both chest physician and radiologist were blinded to the results of other diagnostic method. Diagnosis of PE was suggested if at least one typical pleural-based/subpleural wedge-shaped or round hypoechoic lesion with or without pleural effusion was reported by TUS. Presence of pure pleural effusion or normal sonographic findings were accepted as negative TUS for PE.

RESULTS: PE was diagnosed in 30 patients. It was shown that TUS was true positive in 27 patients and false positive in eight and true negative in 12 and false negative in three. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of TUS in diagnosis of PE for clinically suspected patients were 90%, 60%, 77.1%, 80%, and 78%, respectively.

CONCLUSIONS: TUS with a high sensitivity and diagnostic accuracy, is a noninvasive, widely available, cost-effective method which can be rapidly performed. A negative TUS study cannot rule out PE with certainty, but positive TUS findings with moderate/high suspicion for PE may prove a valuable tool in diagnosis of PE at bedside especially at emergency setting, for critically ill and immobile patients, facilitating immediate treatment decision.”

From the BLUE protocol by Lichtenstein on how to distinguish the various etiologies of shortness of breath, an algorithm was given (see below) which includes the utility of bedside ultrasound for pulmonary embolism diagnosis:

A Profile: anterior A lines bilaterally only – absence of interstitial syndrome – with lung sliding

A’ profile: A profile without lung sliding

B profile – anterior B lines bilaterally with lung sliding

B’ profile – B profile without lung sliding

A/B profile – A lines on one side and B lines present on the other side (asymmetry)

C profile – anterior consolidation (shred sign)

Normal – A profile without PLAPS

PLAPS = posterolateral alveolar and/or pleural syndrome

Thoracic US and the BLUE protocol

A good presentation on thoracic US for pulmonary embolism can be found here:

SonoStudy: Meta-analysis: History & Physical exam with Ultrasound for extremity fractures #FOAMed

I keep thinking about this study published in the Jan 2013 issue of Academic Emerg Med by Dr. Nikita Joshi et al…. for a few reasons… so I thought i would highlight it on SonoSpot and spark some discussion to get your thoughts too. (Get full article here). First off, it’s about a condition that I see in the emergency department on every shift, so it’s incredibly relevant. And, it involves imaging, specifically ultrasound, and how it can benefit the patients with this problem from cost savings to quicker diagnoses and treatment. Finally, the results actually surprised me. Not because ultrasound seemed to be just as good as radiographs, but that they weren’t better. But, I should say that it was a meta-analysis and quite difficult to compare and the study subjects in the meta-analysis all had radiograph proven fractures, and I wonder what would have happened if the xrays were negative but the bedside ultrasound was positive, proven by a gold standard, like CT scan???….  Who am I kidding?! That would involve too much cost, radiation, and time in the emergency department….. Oh wait, I get it….I guess I understand the importance of this study now. There have been quite a few studies on the topic in the last couple years – go here, here, here, here, and here – which makes it really exciting.

The authors start by stating that radiographs do miss fractures:

“The typical work-up of the injured patient generally involves a medical provider obtaining a history and physical examination, often followed by radiologic imaging. However, many times the radiologic imaging may be negative or inconclusive, which calls to question whether the imaging contributed to the management or outcome of the patient. Studies have shown that often the imaging obtained is unnecessary and results in radiation exposure to patients and increased ED wait times.[2]….There’s a low rate of positive radiography when assessing for fractures as evidenced by a retrospective review by Bentohami et al.,[3] in which only 50% of upper extremity x-rays showed fractures, and another study by Heyworth,[4] which showed 15% of patients with ankle injuries had documented fractures on x-ray. In the study by Stiell et al.,[2] patients with ankle injuries had midfoot fracture rates of 4.3%, and 9.3% had malleolar fractures. Therefore, 50% to 95% of extremity x-rays can be avoided without missing fractures.”

Ok, so we know this. Xrays arent great, so why get them? If you think the fracture would need reduction due to a displacement, then ok. But, wouldnt that be possible by physical exam as a deformed extremity so that you’d know to Xray that one? If the extremity is not deformed, but tender and swollen, why not just splint? Isnt that what you would do anyway if the xray was negative due to a high clinical concern for “occult fracture”?

The authors then follow this up with one of my favorite paragraphs on the topic:

“Bedside US has the potential benefits of reducing radiation exposure, costs, and pain, while potentially improving ED patient throughput and satisfaction. This reflects on the original purpose of developing CDRs for extremity fractures. Use of bedside US can help triage patients during a busy ED shift by quickly assessing for the presence of fracture as an adjunct to the normal history and physical examination. It can also aid nurses and physicians who may require more resources for reduction of a fracture.[11] EPs have become more adept at fracture diagnosis through independent review of US and radiographic imaging, and many researchers have examined the ability of EPs to obtain US imaging and diagnose fracture.[12, 13] Additionally, bedside US has excellent diagnostic test characteristics when performed by EPs compared to radiologists in the diagnostic evaluation for soft tissue infections,[14] cholecystitis,[15] pneumothorax,[16] or ruling out ectopic pregnancy.[17]

Love it. See the abstract below and read the entire article to see their limitations and methodology here.

Objectives

Understanding history, physical examination, and ultrasonography (US) to diagnose extremity fractures compared with radiography has potential benefits of decreasing radiation exposure, costs, and pain and improving emergency department (ED) resource management and triage time.

Methods

The authors performed two electronic searches using PubMed and EMBASE databases for studies published between 1965 to 2012 using a strategy based on the inclusion of any patient presenting with extremity injuries suspicious for fracture who had history and physical examination and a separate search for US performed by an emergency physician (EP) with subsequent radiography. The primary outcome was operating characteristics of ED history, physical examination, and US in diagnosing radiologically proven extremity fractures. The methodologic quality of the studies was assessed using the quality assessment of studies of diagnostic accuracy tool (QUADAS-2).

Results

Nine studies met the inclusion criteria for history and physical examination, while eight studies met the inclusion criteria for US. There was significant heterogeneity in the studies that prevented data pooling. Data were organized into subgroups based on anatomic fracture locations, but heterogeneity within the subgroups also prevented data pooling. The prevalence of fracture varied among the studies from 22% to 70%. Upper extremity physical examination tests have positive likelihood ratios (LRs) ranging from 1.2 to infinity and negative LRs ranging from 0 to 0.8. US sensitivities varied between 85% and 100%, specificities varied between 73% and 100%, positive LRs varied between 3.2 and 56.1, and negative LRs varied between 0 and 0.2.

Conclusions

Compared with radiography, EP US is an accurate diagnostic test to rule in or rule out extremity fractures. The diagnostic accuracy for history and physical examination are inconclusive. Future research is needed to understand the accuracy of ED US when combined with history and physical examination for upper and lower extremity fractures.

Nice job Nikita!

UltrasoundPodcast recently did a podcast on Distal radius fractures.

A great video of distal radius fractures can be seen here:

In case you’re curious about how easy it is to visualize a fracture by ultrasound, see image below. That bright white line is bone, and that break is …a break.

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SonoStudy & Tutorial: Factors in testicular torsion diagnosis & treatment #FOAMed

Got to love the Canadians! This topic is also the first case that I posted in SonoSpot’s 1 year history, which reviews technique and an interesting case that baffled us yet becoming more clear with ultrasound (imagine that!). There have also been other case reports that I highlighted speaking about scrotal injuries. In this study, published in AJR, the authors set out to evaluate ultrasound accuracy, findings, and clinical predictors in pediatric testicular torsion. What factors correlate? Now, you could say that you dont need ultrasound and that physical exam alone will diagnose it, but interestingly, and not surprisingly, the physical exam isnt reliable and there have been other diagnoses made by ultrasound that helped rule in other causes of scrotal pain.

This study is a retrospective review, so take that into consideration when thinking about obstacles/limitations to the study, and the actual number of torsion cases was 35. But, it is interesting to note the factors they found with the torsion cases, particularly the ultrasound findings. Looks like color doppler is still good for something! See abstract below:

“OBJECTIVE. Testicular torsion is a common acute condition in boys requiring prompt accurate management. The objective of this article was to evaluate ultrasound accuracy, findings, and clinical predictors in testicular torsion in boys presenting to the Stollery pediatric emergency department with acute scrotal pain.

METHODS. Retrospective review of surgical and emergency department ultrasound records for boys from 1 month to 17 years old presenting with acute scrotal pain from 2008 to 2011 was performed. Clinical symptoms, ultrasound and surgical findings, and diagnoses were recorded. Surgical results and follow-up were used as the reference standard.

RESULTS. Of 342 patients who presented to the emergency department with acute scrotum, 35 had testicular torsion. Of 266 ultrasound examinations performed, 29 boys had torsion confirmed by surgery. The false-positive rate for ultrasound was 2.6%, and there were no false-negative findings. Mean times from presentation at the emergency department to ultrasound and surgery were 209.4 and 309.4 minutes, respectively. Of the torsed testicles, 69% were salvageable. Sensitivity, specificity, and diagnostic accuracy of ultrasound for testicular torsion were 100%, 97.9%, and 98.1%, respectively. Sonographic heterogeneity was seen in 80% of nonviable testes at surgery and 58% of patients with viable testes (p = 0.41).

Sudden-onset scrotal pain (88%), abnormal position (86%), and absent cremasteric reflex (91%) were most prevalent in torsion patients.

CONCLUSION. Color Doppler ultrasound is accurate and sensitive for diagnosis of torsion in the setting of acute scrotum. Despite heterogeneity on preoperative ultrasound, many testes were considered to be salvageable at surgery. The salvage rate of torsed testes was high.”

Among some other limitations, one limitation of this study is the number of torsion cases – I would have liked to have seen more – possibly a multi-site study is needed given the lack of high volume pediatric testicular torsion cases that come to the emergency department every year. Of course, there have been so many studies done that a meta-analysis can be written.

So, when you get that patient with acute scrotal pain, testicle in horizontal or abnormal lie, and an absent cremastreric reflex (and even after you have attempted to de-torse the testicle through the medial to lateral “opening a book” approach – right testicle counter clockwise, left testicle clockwise), place the patient’s leg in an open frog-leg position (you can use a towel under the scrotum to elevate and secure the scrotum in place if the patient tolerates it) and use your longer footprint linear probe. After examining the normal testicle in its transverse, longitudinal and coronal planes with and without color doppler to assess changes in echogenicity and arterial flow, examine the affected testicle the same way. Then, by using the longer footprint linear probe you can examine both testicles in the same view for adequate comparison ability.

Thanks to Dr. Turandot Saul for the images below:

An early ischemic testicle will be enlarged with no change in echogenicity, but a late ischemic testicle will be hypoechoic but may still have preserved structure: testicular torsion early

Also, a late torsed testicle will have abnormal echogenicity and structure: testicular torsion late

Normal testicle has normal echogenicity, normal color doppler flow within testicle:testicule normal flow

Testicle torsion will have absence of testicular flow and may get to the poibnt of hyperemia surrounding the testicle:

testicular late torsion extratestbloodflow   testiculartorsionnoflow

To read a medscape article on testicular torsion and ultrasound findings, go here.

SonoGuide has a great overview of the technique and images of testicular pathology – go here.

The Journal of Ultrasound in Medicine had a good review of the role of spectral doppler in early torsion, go here.

And, of course, Ultrasound Podcast has a great podcast on the how-to of Testicle Ultrasound part 1 and 2:

For another great pictorial review of testicular US and pathology, go here.

SonoStudy: 550 pts, prospective study: How good is ultrasound for traumatic pneumothorax? @westjem #FOAMed

In the march 2013 issue of Western Journal of Emergency Medicine, a study done that has been described as having generalizability, as the ultrasound scans were by many different levels of physicians, prospectively, during a trauma assessment for pneumothorax, has caused quite a bit of discussion. Mostly due to some of the limitations of the study. It is great that a prospective study with some generalizability is seen, but I wonder about the details in the methodology. They begin by discussing the importance and relevance of ultrasound for pneumothorax:

“Rapid diagnosis and treatment of traumatic pneumothorax (PTX) is important to prevent tension physiology and circulatory collapse in patients with blunt and penetrating trauma. Supine chest radiograph (CXR) is traditionally employed; however, it misses up to 50% of PTXs.1 Thoracic ultrasound (TUS) was first described in 1995 for diagnosing PTX in humans when Lichtenstein noted that the absence of comet-tail artifacts and lung sliding were associated with PTX.2 Since then ultrasound has become a validated method of examining the pleura in multiple settings. In 2011 the Eastern Association for the Surgery of Trauma gave a level 2 recommendation for the use of ultrasound to identify PTX in its practice management guidelines.3 In most studies TUS has been found to have favorable results. In Lichtenstein’s study,2 TUS had a sensitivity and negative predictive value of 100% and 96.5%, respectively, for the detection of PTX in the intensive care unit setting.4 Dulchavsky5 subsequently demonstrated that this modality has a sensitivity of 95% in the detection of PTX in patients at a Level 1 trauma center. These reports used plain radiography as the gold standard: a diagnostic modality known to be inaccurate in the detection of PTX.6 In subsequent studies using dedicated chest computed tomography (CCT) as a reference standard, sensitivities of TUS have ranged widely from 49% – 98%, while finding that it is still consistently more accurate than supine CXR.713 Studies in which TUS is performed by emergency physicians (EP) for traumatic PTX have reported even higher sensitivities ranging from 86–97% with specificities of > 99%.14 While these latter numbers are desirable, they have the potential limitation of being less applicable due to a higher skill level of the sonologists involved. The actual performance of TUS for PTX would likely vary based on the sonologist’s skill and experience. The current investigation set out to determine the test characteristics of TUS for traumatic PTX in the hands of a large heterogenous group of potential sonologists representative of typical clinicians involved in trauma care.”

The full abstract is shown below:

“Introduction:

Prior studies have reported conflicting results regarding the utility of ultrasound in the diagnosis of traumatic pneumothorax (PTX) because they have used sonologists with extensive experience. This study evaluates the characteristics of ultrasound for PTX for a large cohort of trauma and emergency physicians.

Methods:

This was a prospective, observational study on a convenience sample of patients presenting to a trauma center who had a thoracic ultrasound (TUS) evaluation for PTX performed after the Focused Assessment with Sonography for Trauma exam. Sonologists recorded their findings prior to any other diagnostic studies. The results of TUS were compared to one or more of the following: chest computed tomography, escape of air on chest tube insertion, or supine chest radiography followed by clinical observation.

Results:

There were 549 patients enrolled. The median injury severity score of the patients was 5 (inter-quartile range [IQR] 1–14); 36 different sonologists performed TUS. Forty-seven of the 549 patients had traumatic PTX, for an incidence of 9%. TUS correctly identified 27/47 patients with PTX for a sensitivity of 57% (confidence interval [CI] 42–72%). There were 3 false positive cases of TUS for a specificity of 99% (CI 98%–100%). A “wet” chest radiograph reading done in the trauma bay showed a sensitivity of 40% (CI 23–59) and a specificity of 100% (99–100).

Conclusion:

In a large heterogenous group of clinicians who typically care for trauma patients, the sonographic evaluation for pneumothorax was as accurate as supine chest radiography. Thoracic ultrasound may be helpful in the initial evaluation of patients with truncal trauma.”

So what are the limitations? They describe a few of them:

The technique: “The TUS examination consisted of the consecutive sonographic interrogation of every intercostal space between the clavicle and the diaphragm on each hemithorax. Scans were performed in the mid-clavicular line. On the left side, if cardiac motion was encountered in the mid-clavicular line, the probe was moved laterally to the left anterior axillary line and the pleura seen in the remaining intercostal spaces was evaluated until the diaphragm/spleen was encountered. To use the ribs to assist in the identification of the rib spaces and the pleura, the probe was placed in a longitudinal plane for the entire exam.” So, would this have increased their sensitivity or specificity as they include all rib spaces? Not too sure. Is this truly generalizable if the technique is different than how most perform the quick E-FAST? no. The main reason for the technique, i imagine, is to find the lung point which is far more specific for pneumothorax.

The Probe and Machine – The low frequency curvilinear probe was used on an older ultrasound system – SonoSite Titan. Could this have affecte their results? Would the increased resolution of a linear probe have helped their evaluation on the newer machines? It is possible, but by how much? who knows.

The comparison group: “Not all subjects underwent CCT and instead just had CXR and clinical observation. It is possible that some patients in this latter group had radio-occult PTX that may have been visualized on CCT leading to misclassification bias. Such a bias could result in a lower sensitivity rate for both TUS and CXR, however would likely not affect the accuracy of these tests for determining clinically significant PTX.” It is tough to have a standard and if only the chest CT group were compared, it may have had different results.

Im hoping to see more studies like this one where more generalizability is seen, and not studies done only by the experts, so that we can have a true assessment. It is best done using the technique most commonly performed (using only the second intercostal space and mid clavicular line and trying to ind the lung point if absence of lung sliding is seen) at multiple-sites, with increased power to the study, all compared to a CT as the imaging gold standard. But, i can dream, as that is quite difficult to accomplish, and the authors did a pretty nice job with what they had, got pretty good numbers of subjects – something to ponder….

For a prior post on pneumothorax and a link to the CHEST meta-analysis, go here.

For a SonoTutorial post on pneumothorax ultrasound, go here.

Another study stating that ultrasound can be used to assess post=procedure pneumothorax published in June 2013 of JUM, go here.

SonoStudyReview: The Pneumothorax by @EMLyceum – EBM review on imaging/diagnosis/treatment #FOAMed

If there ever was a post worth reading about pneumothorax, this excellent review by EM Lyceum was too good not to pass along to everyone. Now I don’t know about you, but I always get asked the questions about chest Xray versus Ultrasound, what to do when only the ultrasound shows the pneumothorax (because you know it’s better than Chest Xray! as discussed in a prior post), when to order that CT chest, and how should you treat it: nothing? pigtail? small chest tube? large chest tube? EM Lyceum does a great job in reviewing this using literature to back it up. There have been more studies that haven’t been mentioned with regard to ultrasound and pneumothorax diagnosis, and the sensitivity and specificity of chest xray is stated pretty high as prior studies tend to do (with more accurate and recent ones stated by EM Lyceum to be lower (in the real world that we work in). And, there was a great meta-analysis in Chest Journal speaking of which imaging modality was better, chest Xray or ultrasound. Go to the EM Lyceum site and read-on to grasp the answers to all the questions! Thank you EM Lyceum – this was awesome!

Screen Shot 2013-04-30 at 5.32.49 PM

By BTS 2010 guidelines (Macduff, 2010).

#AIUM13 for an EM doc: Part 1- All about Ultrasound in Medical Education- by the experts & EBM review #FOAMed

The American Institute of Ultrasound in Medicine (AIUM) 2013 conference in New York City was the best AIUM I have ever been to, and it continues to open up my mind (having my ideas run wild!)  to so many things that ultrasound will do for medicine, while reminding me of the up-to-date studies that clarify many ultrasound-related topics in medicine. It is true that Ultrasound should be considered first with many conditions, and as an emergency physician, point-of-care bedside ultrasound is definitely an example of that. It absolutely should also be implemented into medical school education to have a head-start at becoming an excellent physician. AIUM has an emergency and critical care section too and I have taken full advantage of the information there, as should you. (Jason Nomura has gathered all AIUM13 tweets for your reading pleasure for all AIUM13 topics)

IMG_1144 YOU = Year of Ultrasound!

This post is a one part of a 4-Part Series where I discuss all the lectures, panel discussions, and events that i attended there, and what every emergency doctor should get out of it, and the literature that backs it up or discusses the controversy – all through my and other’s twitter feed with the addition of some links to relevant material.

The first day was one of my favorites! It was the Ultrasound in Medical Education panel discussion from the experts, coordinated by Dr David Bahner, who has recently published study after study after study after study with regard to how he incorporated ultrasound into medical education and how to standardize ultrasound education. You can even listen to and view the whole course if you have an AIUM membership, by going here. Dr. Richard Hoppman, the Dean of University of South Carolina, who has also published study after study after study after study on this topic, also gave his pearls and wisdom from the Dean’s perspective. (Hear/View his interview with UltrasoundPodcast by going here.) Other experts also gave their expertise in this hot topic, as they have also published and highlighted study after study after study after study as shown below in the tweet and panels’ pearls from the course (as well @SonoMedED tweets who provided more highlights for the course): Ultrasound in Medical Education (I posted on the comparison of Ultrasound to physical exam previously – but there is so much I need to add to it now!)

AIUM’s Ultrasound First Declaration- Integration of US into Medical School Curricula

a. Provide clinicians with resources to guide medical student training in clinical ultrasound to better provide care for their patients

b. Provide educators with the resources and tools to coordinate clinical ultrasound in medical curricula

c. Provide researchers with evidence based resources to create and validate new knowledge through innovative and rigorous academic pursuits

d. Provide administrators with data and contact personnel at respective medical institutions who are applying novel ultrasound education across the medical spectra

e. Provide medical students with a one-stop portal to navigate current United States medical student ultrasound education and opportunities to get in school

1. David Bahner – This would involve changing curricula, training faculty, acquiring equipment, support staffing, quality assurance, OSCE or SDOT, establish “best-practices.” In 2004, the medical organizations differentiated & defined ultrasound into four categories: Comprehensive, Focused, Procedural, Physical exam aid

2. D. Lichtenstein - “They call me Dr. Lung, but I do more.” There are exciting ways to show medical students the importance of ultrasound….New territories of ultrasound: mesenteric ischemia (“a bowel that doesn’t move is a dead bowel”), pneumoperitoneum, increased ocular use. Took 15 publications in order to publish the BLUE protocol that reviews 10 signs of lung US. Respiratory failure: BLUE http://crashingpatient.com/wp-content/uploads/2011/07/Lichtenstein-Slides.pdf … ; Circulatory failure: FALLS (if no B lines then good systolic fxn; if B lines then bad systolic function); Cardiac Arrest: SESAME protocol (lung sliding (if pneumothorax- immed interv), echo, then IVC and AAA at your discretion: http://www.slideshare.net/nswhems/the-arrested-patient … Lung Ultrasound in Critically Ill for Limiting Radiographs (LUCIFLR) project  - to decrease CT and chest Xrays (but not to eradicate Xrays “or LUCIFLR will = LUCIFER”). Lung ultrasound can limit the need for chest X-rays in the ICU and the ED.

3. Creagh Boulger – speaking on literature review of ultrasound curriculum for medical students. MT “@SonoMedED: Medical students effectively use ultrasound in just 5 min in some situations.” [Even beating clinicians in diagnosis! See: this study.] . Study after study has shown that medical students benefit from ultrasound in medical education. How to fit it into the schedule? what they did – online didactics (like Fox’s iTunes series), then 16 weeks of hands-on, concluded with a checklist based assessment. Why teach it? Increases Anatomy Learning, increases diagnostic ability in radiology, assists in spatial relationships, and they see “live anatomy” with better ability to learn physiology in real-time.

4. Social Media and Ultrasound Learning – MT “@SonoMedED@EDUltrasound and @EDUltrasoundQA Uses Twitter with daily tweets to teach ultrasound with social media.” …In addition to little ole me (@SonoSpot), @SonoTron, @TheSonoCave, @bedsidesono, @Ultrasoundpod, @westernsono, @sinaiemus, @UTS_Australia, @USEDCDN … and many others who are in emergency medicine/critical care and highlight ultrasound with their own pearls.

5. John Pellerito –  how to incorporate US into med school: buy in from Dean, faculty training, facility space, US equipment, MULTI-specialty involvement (emergency medicine, radiology, critical care, obstetrics, medicine, surgery). US in med school: online didactics, most time must be spent with hands-on: knobology, anatomy, physiology, pathology (- partner with pathology /radiology dept to show how ultrasound correlates with histology/specimens and CT/MRI [they will learn to read those better too by learning ultrasound!]). Society of US in Med Ed (SUSME) website to see sample curriculum. The Challenges of incorporating US into Medical Education: maintenance of longitudinal curriculum, keep faculty enthusiastic, budget for new equipment, space needs. MT“@SonoMedED: Challenges with med stud ultrasound educ 4yr curriculum, keep faculty interested.  pic.twitter.com/UnRSCGs0vk”. Who to Train them? First will be faculty, then the seniors can teach the juniors. Essentials im developing an US curriculum: didactics and hands-on training, integration into anatomy, physiology, physical exam and diagnosis skills, clinical clerkships, and requires student assessment and image archiving and review. Faculty/Facility needs: classroom, bedside, anatomy lab, stretchers, gel, towels, monitors, models (students or patients), faculty from multiple specialties

6. Amponsah/Jackson – from Wayne State : how they incorporate US in med stud curriculum: didactics, 2nd yr competency test, multi-specialty involvement. Where US helps med stud in anatomy learning: spatial relations, pathology, live anatomy pic.twitter.com/MCI972lryO . Need high faculty:student ratio. LCME requirements are key to getting ultrasound into medical school:

LCME requirements are a great way to advocate for ultrasound education as part of active learning for medical students …..The following LCME requirements can be satisfied with ultrasound: ED-5-A: A medical education program must include instructional opportunities for active learning and independent study to foster the skills necessary for life-long learning; ED-12: The curriculum of a medical education program should include laboratory or other practical opportunities for the direct application for the scientific method, accurate observation of biomedical phenomena, and critical analysis of data; ED-28:A medical education program must include ongoing assessment of medical student’s problem solving, clinical reasoning, decision making, and communication skills.

7. J. Christian Fox – From UC Irvine.  pic.twitter.com/znUAea1wew . Bridging the gap between pre-clinical and clinical students with simulations: How to do it: transitioning from pre-clinical to clinical medical students: podcast, then hands-on with healthy volunteer, then task trainer, then recognize pathology on simulator, then standardized patient with pathology, then clinical rotation utilization by way of an OSCE  pic.twitter.com/ix4Rl2X4WS “Sono-genic” models great to use- models with great US anatomy. Issues in real patients: obesity, COPD, pain- all limit scan ability but great for later training. Great models: Sono-Studs… Or, not so good: Sono-Mess MT“@SonoMedED: Terms for good sonographic models…Sonogenic…Sonolicious.” (Ah, I digress…). Solve issue of assessing pathology: simulation! Various simulators are on the market: http://Sonosim.com , http://bluephantom.com  ,http://Vimedix.com http://www.medaphor.com/  , http://www.medsim.com/ultrasim.html . MT “@SonoMedED: Dr. Fox signs up pts for modeling with various pathologies. Model pts with pathology compensated $80 for 4 hour session. Often challenging to schedule patients though.” Great way to get models who have pathology! Studies show increasing ultrasound performed in ED when increased medical student ultrasound learning, also that liver span size better when use ultrasound. Medical students are better with ultrasound in diagnosing cardiac disease when compared to cardiologists’ physical exam.

8. Michael Blaivas - The role of specialty organizations- AIUM, SUSME, WINFOCUS, and specialty specific: ACEP, SAEM, ACS, ACOG, ACCP, SCCM, Card, Rads. http://SUSME.org  primary purpose is integrating US into med educ. http://WINFOCUS.org  primary purpose to help proliferation of Ultrasound education, is worldwide, has detailed US educ curriculum, policy making depending on region/country. Summary- issues and specialty organization – how they help  pic.twitter.com/ZsO9BKWa6B

9. Dean Richard Hoppman – from University of South Carolina:  pic.twitter.com/hAx4Iqv9rR . US in medical education- A Dean’s Perspective, how to get them on your side: how to get US in medical education- get medical students on your side, show US enhances medical education, satisfies LCME requirements, fits all types curriculum. When ultrasound becomes part of Step 2 exams is when you know we’ve arrived… [Wow! Can u imagine?!]….Ultrasound competency could be an advantage to residency application. Even if they don’t use US in residency, can order/ interpret/understand ultrasound and other radiology studies better, they’ll think Ultrasound First! How ultrasound adds value to institution  pic.twitter.com/dzJt0VAaNE . Hopefully one day ultrasound training will be a requirement for medical school graduation. How to fund ultrasound for your institution  pic.twitter.com/uItTHJj2Jb . MT“@SonoMedED: Universities increasing focus on entrepreneurship. patent ultrasound ideas or devices. Help fund program” Great idea by Hoppmann -> MT “@SonoMedED: Advocate option for donors to contribute to medical school ultrasound programs.”The new stethoscope? MT“@SonoMedED: Grants supply equipment for med studs, even handheld units.  pic.twitter.com/5t9wbOtsef” medical students love it, medical students become alumni, alumni become donors. Great way to advocate for it pic.twitter.com/TnxBLjhsJn. Dean’s summary message to all: Get it. Learn it. Do it. Teach it. For your patients & healthcare  pic.twitter.com/LfUQv2SbJK . Yes!!-> “@SonoMedED: Great insight from Dean Hoppmann. pic.twitter.com/VcW1BUmbRl

10. Teresa Liu – from GW  (the one who is putting it all together for med studs at AIUM/SAEM/ACEP). White paper on ultrasound in medical student education is in progress. ACGME now incorporates ultrasound into EMed and RRC doing same for rheumatology. Medical students can get involved in specialty organizations/journals focused in ultrasound: JUM, Acad Med, SUSME/SAEM/AIUM/ACEP. Lower cost-Increased use! -> MT“@SonoMedED: Liu- need for making US tech more affordable to better penetrate into all specialties.”

11. Alex Levitov- curriculum and competency assessments: challenges & opportunities. Driving force for ultrasound are many clinical cases where it’s relevant & when time matters: its a busy day or patient critical.When people ask why – tell them this:  pic.twitter.com/CUth7L3Vxj . US allows immediate diagnosis, immeidate data in patient care, & allow reassessment after intervention (CVC placement, chest tube, foley…). Competency in US- image acquistion in years 1/2 ; Simulators, clinical cases & they decide what to do next for years 3/4. US in meded-cardiac physiology usually rated low by medical students, but rated high after ultrasound used to enhance education. Best way to incorporate US in medical education- staged approach -& use clinical cases early, ask about interventions in clinical years

12. Vicki Noble- from Mass General – discusses Ultrasound Competency -NEJM article -Point of Care Ultrasonography shows how many use it . “Numbers” for image acquisition competency- should it exist? Arguments for & against exist. Outcome need to be different? “Consensus is great, paralysis is bad”-concept of plateau-do more of same if literature show numbers don’t matter may mean we should change. US competency numbers may be different for different ultrasound applications; numbers may not matter for some applications- testing image interpretation requires clinical integration & “next step” questions. Online ACEP US test: http://www.emsono.com/acep/exam.html 

13. James Palma- from Georgetown – web based & organizational considerations in ultrasound in med ed – organ based approach – online didactics; hands on. web based US curriculum pic.twitter.com/l9fuWycluk

14. Last but not least – MEDICAL STUDENT PANEL !! Medical students panel discussing how #ultrasound helps them -going into different specialties pic.twitter.com/4B8IjKjtTQ . Ultrasound helps spatial relations in anatomy, great for MSK in real time (ie. rotator cuff movement), heart great to match with physiology (“it’s hard to understand heart physiology by reading a book, and so much better when you see the valves opening and closing and how the heart pumps”) . Great to see kidney ultrasound because anatomy dissection takes all abdominal organs out & can’t appreciate spatial relations. “@SonoMedED: Med Student Panel-Ultrasound physiology best demonstrated for IVC collapsibility and ejection fraction.” When asking medical student their preference: separate course versus full integration in different classes with regard to ultrasound into medical education: all wanted the latter – unanimously! . Story by a medical student: Psychiatric ward patient w/ abdominal pain got hand-held ultrasound by medical student showing cholecystitis- comprehensive ultrasound confirmed; OR that day. MT“@SonoMedED: Med Stud Panel-key to making integration of ultrasound successful: make it clinically relevant in 1st/2nd year.”  “Ultrasound makes me feel that I can contribute to the team.” 

15. Prior advances in Ultrasound in Medical Education has been highlighted by others: I have posted about how ACEP, AAMC, and AIUM last year has started speaking about ultrasound in medical education; UltrasoundPodcast have a great podcast about it and how to incorporate it here and here; WesternSono posted about this from the Canadian perspective with an amazing and fun talk pitching ultrasound training in medical education here;  the world is advancing this goal as well!

Some of the great slides that grabbed my attention from the AIUM13 course: (apologies for the blurry iPhone images)

IMG_1158IMG_1159IMG_1161 IMG_1163IMG_1164IMG_1168

The Medical Student Panel:

IMG_1169

The Course’s Faculty: aka – the All-Stars!

IMG_1170

And, to conclude with great insight and words of wisdom for why ultrasound should be in medical education:

And what he has done to spread the gospel of ‘sound! – go here to read more and hear a speech done by the Dean of UC Irvine Medical School on why its so important to incorporate ultrasound into medical education for our patients.

SonoStudy: Meta-analysis of 9 trials – ultrasound use for peripheral IVs in kids and adults #FOAMed

Not that we didnt already know this, but at least we have more data to say it is so – in a recent study in Annals of Emergency medicine – a meta analysis reviewed 9 trials – both kids and adults.

This concept has been getting a lot of press, and many of my ultrasound enthusiast friends have passed this around. It’s good to know the concept – and use it when you are in a conversation with someone who thinks the blind technique it still the way to go.

“Pediatric trials yielded conflicting data, the authors reported February 18 online in Annals of Emergency Medicine, but there appeared to be significantly fewer attempts and shorter procedure times when ultrasound guidance was used in the emergency department, as well as significantly decreased risk of first-attempt failure, reduced attempts, and shorter procedure time when ultrasound guidance was used in the operating room…..”Ultrasonographically guided peripheral intravenous cannulation may perform better in the pediatric population because failure rates with the traditional method are much higher in children than adults,” the researchers note. “Ultrasonography may not be as beneficial in adults, in whom target vessels are easier to locate.” – Now, these trials were from operating room patients, where the setting is a bit more controlled, the patients may be a bit different in their difficult IV access spectrum – but the authors still suggest that if faced with a difficult IV – use ultrasound.

Below is the abstract:

Study objective

Peripheral intravenous cannulation is procedurally challenging and painful. We perform a systematic review to evaluate ultrasonographic guidance as an aid to peripheral intravenous cannulation.

Methods

We searched MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, ClinicalTrials.gov, and Google.ca. We included randomized trials evaluating ultrasonographically guided peripheral intravenous cannulation and reporting risk of peripheral intravenous cannulation failure, number of attempts, procedure time, or time from randomization to peripheral intravenous cannulation. We separately analyzed pediatric and adult data and emergency department (ED), ICU, and operating room data. Quality assessment used the Cochrane Risk of Bias Tool.

Results

We identified 4,664 citations, assessed 403 full texts for eligibility, and included 9 trials. Five had low risk, 1 high risk, and 3 unclear risk of bias. A pediatric ED trial found that ultrasonography decreased mean difference (MD) in the number of attempts (MD −2.00; 95% confidence interval [CI] −2.73 to −1.27) and procedure time (MD −8.10 minutes; 95% CI −12.48 to −3.72 minutes). In an operating room pediatric trial, ultrasonography decreased risk of first-attempt failure (risk ratio 0.23; 95% CI 0.08 to 0.69), number of attempts (MD −1.50; 95% CI −2.52 to −0.48), and procedure time (MD −5.95; 95% CI −10.21 to −1.69). Meta-analysis of adult ED trials suggests that ultrasonography decreases the number of attempts (MD −0.43; 95% CI −0.81 to −0.05). Ultrasonography decreased risk of failure (risk ratio 0.47; 95% CI 0.26 to 0.87) in an adult ICU trial.

Conclusion

Ultrasonography may decrease peripheral intravenous cannulation attempts and procedure time in children in ED and operating room settings. Few outcomes reached statistical significance. Larger well-controlled trials are needed.

For more info and a how-to for ultrasound guided procedures, including ultrasound-guided peripheral IV and central IV acces – go here.

SonoStudy: Emergency docs detect small bowel obstruction by US – as good as radiologists #FOAMed

In a recent article in the European Journal of Emergency medicine, the authors showed that emergency physicians are just as good as radiologists in detecting small bowel obstruction by bedside US. Now, it’s not hard to do, nor is it hard to see it. First off, use your abdominal low frequency probe, and evaluate the abdomen in different quadrants. Normally, the bowel appears as a single circular hypoechoic layer (muscle layer) surrounding hyperechoic bowel contents of gas and food particles. The normal thickness of this layer during the contraction stage of peristalsis is 2-3 mm. The hypoechoic normal wall becomes thinner during peristalsis when the bowel is relaxed.

In small bowel obstruction- looking for dilated fluid filled loops of bowel with hyperechoic (bright) spots within it that may have back and forth peristalsis and a thicker intestinal wall (decreased persitalsis is a late finding) – color doppler gives info about blood flow in the walls of the intestine – and you may even see a transition point. Timothy Jang and team studied ultrasound compared to Xray for SBO and found that ultrasound is better, like WAYYYY better (higher sensitivity and specificity) – hmmm, interesting – Some things to consider: fluid-filled loops (good for US), but air-filled loops may not be so good. Ileus and SBO may appear similarly, so consider thinking of causes of ileus as well (gallstone ileus, etc), and a thickened wall may just be colitis, but that along with dilated loops and back and forth persitalsis with a transition point seen – more likely SBO.

This is what it would look like (and there are more clips to view – thanks to SonoCloud)

The abstract of the study follows:

“Objective: Our objective was to study the accuracy of emergency medicine [(EM) bedside ultrasonography (BUS)] and radiology residents performed ultrasonography (RUS) in patients with suspected mechanical small bowel obstruction (SBO).

Methods: After a 6-h training program, from January to June 2009, four EM residents used BUS to prospectively evaluate the patients presenting to the emergency department with suspected SBO. Then, patients underwent RUS. Outcome was determined by surgical findings if they were operated upon or self-reported the condition upon telephone follow-up at 1-month. BUS and RUS results were compared with χ2 testing.

Results: Of the 174 enrolled patients, 90 patients were BUS-positive. Of these, surgical findings agreed with the BUS findings in 84 patients. In 78 cases, BUS was negative, and 76 of these patients had benign clinical courses. Six patients were excluded from the study. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio for BUS were 97.7, 92.7, 93.3, 97.4, and 13.4%, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value for RUS were 88.4, 100, 100, and 89.1%, respectively. The diagnostic accuracy of BUS and RUS were not statistically different from each other (κ=0.81). The presence of dilated small bowel loops (>25 mm in jejunum or >15 mm in ileum) was the most sensitive (94%) and specific (94%) sonographic finding for SBO.

Conclusion: Abdominal sonography for the diagnosis of SBO is a new application of BUS in the emergency department. EM residents can diagnose SBO using BUS with a high-degree of accuracy, comparable with that of radiology residents.”

To read the UltrasoundPodcast guys speak on the subject, click here>

To see them do it, see below:

SonoStudy and Review: The Beta hCG, the Ectopic, and the Ultrasound Findings – do they correlate?

In a recent article in the Journal of Ultrasound in Medicine (through AIUM), a study was done that illustrates exactly what we all experience in practice – an ectopic pregnancy can occur at any beta hCG level….AND a normal pregnancy can result despite a higher bHCG and no IUP seen. The conversations with the radiologists who still believe in “screening” who should and should not be scanned based solely on the beta hCG level will minimize – so we hope. The lowest beta hcg I have ever seen with a diagnosed ectopic? Brace yourselves…….152 ! There have been other case reports and cohort multi-site studies that you can read herehere, here, and here about low hCG and diagnosis of ectopic pregnancy. ACEP even has an article on it. But what if the beta hCG is high? …and you see nothing in the uterus on your ultrasound? There was a study done in 2011 by Wang, et al out of UCSF that discussed this too, asking if we should increase the discriminatory zone. There are also studies that show if you DO see something in the uterus, what does that mean in relation to ectopic pregnancy? Well, first, let’s talk physiology – Now, hCG is made by the syncytiotrophoblasts of the placenta after fertilization occurs, and correlates with the size and developing of the fetus…. well, Im going to stop there, as the only reason I stated that was to type “syncytiotrophoblasts” as I rarely have the opportunity to do so (insert sarcasm).

There is, however, a term used to describe the maternal serum hCG level above which a gestational sac should be consistently visible on transvaginal sonography – “discriminatory zone” – coined in the 1980s (yup, that’s right, 30 years ago!). This was thought to be 1,000, 1,500, or 2,000 on transvaginal ultrasound (and 3,600 or 6,000 on transabdominal ultrasound) depending on the study you read. So, if the hCG is above that zone and no IUP is seen – then you have yourself an ectopic pregnancy ….until proven otherwise! – and doctors would think treating for ectopic is the appropriate next step. Then there was a hiccup – There was a study that showed an HCG of 2,000 may not mean ectopic as 33% of the study’s subjects had a normal IUP after having no IUP on ultrasound when they were above that discriminatory zone. Oopsy! But, the prior studies all kinda had a possible gestational sac, but defined an IUP as the presence of a double decidua sign or yolks sac. So, this study wanted to know if there was no gestational sac and the bHCG was above this discriminatory zone, will there be an IUP, and if so, then what is the prognosis – in other words, is this discriminatory zone be valid?

“Objectives—The human chorionic gonadotropin (hCG) discriminatory level—the maternal serum β-hCG level above which a gestational sac should be consistently visible on sonography in a normal pregnancy—has been reported to be 1000 to 2000 mIU/mL for transvaginal sonography. We assessed whether a woman with a β-hCG above 2000 mIU/mL and no intrauterine fluid collection on transvaginal sonography can subsequently be found to have a live intrauterine gestation and, if so, what the prognosis is for the pregnancy.

 Methods—We identified all women scanned between January 1, 2000, and December 31, 2010, who met the following criteria: serum β-hCG testing and transvaginal sonography were performed on the same day; β-hCG was positive and sonography showed no intrauterine fluid collection; and a live intrauterine pregnancy was subsequently documented. We tabulated the β-hCG levels in these cases and assessed pregnancy outcome.

Results—A total of 202 patients met the inclusion criteria, including 162 (80.2%) who had β-hCG levels below 1000 mIU/mL on the day of the initial scan showing no intrauterine fluid collection, 19 (9.4%) with levels of 1000 to 1499, 12 (5.9%) 1500 to 1999, and 9 (4.5%) above 2000 mIU/mL. There was no significant relationship between initial β-hCG level and either first-trimester outcome or final pregnancy outcome (P> .05, logistic regression analysis and Fisher exact test). The highest β-hCG was 6567 mIU/mL, and the highest value that preceded a liveborn term baby was 4336 mIU/mL.

[Also: "Comparing outcomes in cases with β-hCG below 1000 versus above 1000 mIU/mL also showed no significant difference: 89.9% (125 of 139) live at the end of the first trimester in the low hCG group versus 88.6% (31 of 35) live in the high hCG group; 86.6% (110 of 127) liveborn in the low hCG group versus 80.6% (25 of 31) liveborn in the high hCG group (P > .05 for both comparisons Fisher exact test)]“

Conclusions—The hCG discriminatory level should not be used to determine the management of a hemodynamically stable patient with suspected ectopic pregnancy, if sonography demonstrates no findings of intrauterine or ectopic pregnancy.

 A great discussion on this also heard here BroomeDocs’ Casey Parker: here

For a great 5 minute talk on Ectopic pregnancy and how to identify it by ultrasound, see Dr. Phil Perera’s Soundbytes insert – but, as the studies above suggest, if you see no IUP despite an hCG above the discriminatory zone, there may not be an ectopic pregnancy – make sure to look around the adnexal region, and have close follow up with the Ob/Gyn doctor.

SonoStudy: Thoracic ultrasound in identifying pneumothorax progression in the intubated – the lung point

In the Feb 2013 issue of Chest, Oveland et al studied porcine models, introducing air at incremental levels to identify if thoracic ultrasound is as accurate as CT scanning for the detection pneumothorax progression in the intubated patient. They found that “the accuracy of thoracic ultrasonography for identifying the lung point (and, thus, the PTX extent) was comparable to that of CT imaging. These clinically relevant results suggest that ultrasonography may be safe and accurate in monitoring PTX progression during positive pressure ventilation.”

“Background:  Although thoracic ultrasonography accurately determines the size and extent of occult pneumothoraces (PTXs) in spontaneously breathing patients, there is uncertainty about patients receiving positive pressure ventilation. We compared the lung point (ie, the area where the collapsed lung still adheres to the inside of the chest wall) using the two modalities ultrasonography and CT scanning to determine whether ultrasonography can be used reliably to assess PTX progression in a positive-pressure-ventilated porcine model.

Methods:  Air was introduced in incremental steps into five hemithoraces in three intubated porcine models. The lung point was identified on ultrasound imaging and referenced against the lateral limit of the intrapleural air space identified on the CT scans. The distance from the sternum to the lung point (S-LP) was measured on the CT scans and correlated to the insufflated air volume.

Results:  The mean total difference between the 131 ultrasound and CT scan lung points was 6.8 mm (SD, 7.1 mm; range, 0.0-29.3 mm). A mixed-model regression analysis showed a linear relationship between the S-LP distances and the PTX volume (P < .001).

Conclusions:  In an experimental porcine model, we found a linear relation between the PTX size and the lateral position of the lung point. The accuracy of thoracic ultrasonography for identifying the lung point (and, thus, the PTX extent) was comparable to that of CT imaging. These clinically relevant results suggest that ultrasonography may be safe and accurate in monitoring PTX progression during positive pressure ventilation.”

Full article found here.

To see the lung point, you visualize the pleural line using the linear probe (indicator toward the patient’s head) starting from anterior chest wall (2nd intercostal space, mid-clavicular line) to inferior-lateral chest wall, and look out for the area where the lack of lung sliding or comet tail artifacts reverts back to normal lung sliding with comet tail artifacts. Blaivas, et al, studied this, showing that bedside ultrasound can detect size of pneumothorax through identification of the lung point location. Below is a video fo the lung point: