The AHRQ recently published an update to its landmark 2001 report, Making Health Care Safer: A Critical Analysis of Patient Safety Practices (AHRQ Evidence Report No. 43). This report advocated evidence-based practices such as root cause analysis, hand hygiene, ID bracelets for high risk patients, and time-outs prior to procedures.

The 2013 update analyzed 41 patient safety practices and identified 22 which were deemed ready for adoption. Ten were selected as “strongly encouraged” for adoption based on the strength and quality of evidence. Number nine on that list was “Use of real-time ultrasound for central line placement.”

A special supplement to the March issue of Annals of Internal Medicine features articles related to many of these patient safety strategies, and is available for free online.

Looking through the top ten list, most interventions are implemented at most major hospitals, and JCAHO surveyors track adherence to guidelines such as these. Now that ultrasound use has made the top ten in two iterations of these AHRQ safety practices, it may be more difficult to argue that lack of availability or proper training absolves providers of the need to provide this service.

The AHRQ recently published an update to its landmark 2001 report, Making Health Care Safer: A Critical Analysis of Patient Safety Practices (AHRQ Evidence Report No. 43). This report advocated evidence-based practices such as root cause analysis, hand hygiene, ID bracelets for high risk patients, and time-outs prior to procedures.

The 2013 update analyzed 41 patient safety practices and identified 22 which were deemed ready for adoption. Ten were selected as “strongly encouraged” for adoption based on the strength and quality of evidence. Number nine on that list was “Use of real-time ultrasound for central line placement.“

A special supplement to the March issue of Annals of Internal Medicine features articles related to many of these patient safety strategies, and is available for free online.

Looking through the top ten list, most interventions are implemented at most major hospitals, and JCAHO surveyors track adherence to guidelines such as these. Now that ultrasound use has made the top ten in two iterations of these AHRQ safety practices, it may be more difficult to argue that lack of availability or proper training absolves providers of the need to provide this service.

This symposium is always worth the trip.  See you there.

It’s been out awhile now, but if you haven’t seen it yet, take a look at Mike and Matt’s Introduction to Bedside Ultrasound.  The ultrasound pocast guys have released this excellent overview of point of care ultrasound through the iTunes Store.  This is certainly convenient as most of us have 3-12 iDevices on our person at any one time.  Caveats are that this means that it is available only on an iPad using iBooks 2 or later, and ios 5 or later.  Right now it is $29.99.

There is a lot of good content, but I think the best chapter in the book, is probably the RUSH chapter. :)

More lung ultrasound tips and examples from Drs. Jim Tsung and Brittany Pardue Jones!

Subpleural consolidation:

Confluent B-Lines:

occur when multiple B-lines coalesce. In contrast, the next example demonstrates multiple discrete B-lines.

Multiple B-Lines:

And now for something completely different

For more details on the sonographic appearance of viral lung pathology, check out this article by Jim Tsung.

The FAST exam is generally described as a trauma assessment (hence the acronym). But it is often used as a metanym to mean any assessment of the peritoneum for fluid. In fact when I was a resident folks would often say, “let’s FAST that gallbladder,” or “get the FAST machine so we can put that central line in.” And we didn’t have Twitter.

Anyway, here are a few cases where the “FAST” was used in a non-trauma patient to assess the peritoneum:

Cirrhotic with abdominal pain and tenderness:

https://gmep.org/media/12027

who was found to have ascites, and spontaneous bacterial peritonitis

Lower abdominal pain in pregnancy:

who was found to have hemoperitoneum from a ruptured ectopic pregnancy

Diffuse abdominal tenderness in a healthy ten-year-old:

who was found to have an idiopathic seromas of the peritoneum, pleura, and pericardium!

Shortness of breath and abdominal distension:

which turned out to be massive abdominal abscesses

Diffuse abdominal tenderness and distension after hysteroscopy:

which was complicated by a bowel perforation; hence fecal material throughout the peritoneum

Take home points:

• Assessment of the peritoneum greatly aids medical and surgical diagnoses
• Fluid appears black (anechoic) on ultrasound. Very difficult to tell what TYPE of fluid by appearance alone
• Your clinical assessment must guide the differential diagnosis for your ultrasound findings

Here’s a quick trick:

When the Transeptic spray bottle won’t spray, it is often because the pump has become disconnected from the plastic tubing within the bottle. Instead of trying to fish it out with forceps, just turn the whole bottle upside-down.

Disinfectant Spray Bottle Troubleshooting from Sinai EM Ultrasound on Vimeo.

I hope this takes away just one small annoyance on your next shift. Unfortunately this will leave room for another, larger annoyance to occupy the space.

Counter-intuitively, when insonating the lungs of healthy patients, we don’t “see” lung tissue. Instead we see and interpret artifacts arising from the pleural lines and the diaphragm.  These artifacts change with pulmonary disease processes.  In pneumonia, the airway spaces become inspissated with bacterial byproducts and consequently the sonographic appearance of lung tissue changes.

The transformation of lung tissue is termed hepatization: the lung tissue now appears similar to liver tissue.

This can be confusing in the lower lung fields, especially adjacent to the diaphragm because we use the mirror image artifact of the liver and spleen to indicate that lung tissue is normal. This mirrored, artifactual splenic or liver appearance could then be called pseudo-hepatization.

So, how do we differentiate hepatized lung versus pseudo-hepatized lung?

1. Never use a single image for your diagnosis, scan through area and convince yourself (then save a representative image or clip for QA).
2. Be systematic and scan down from the lung apices to the diaphragm.
3. Hunt for the diaphragm and use it as a dividing line between the lung and the abdominal organs.
4. Hepatized lung will often have a rim of fluid around it.

Image 1: Normal lung with visible diaphragm

Ultrasound of lung and spleen from Sinai EM Ultrasound on Vimeo.

Image 2: Normal lung with obscured diaphragm

Lung and Spleen Interface on ultrasound from Sinai EM Ultrasound on Vimeo.

Image 3: Hepatized lung at the lower lung field

So we are scanning the left thorax in a patient with shortness of breath, in an effort to assess for pleural effusion. The following video was obtained:

The operator correctly noted the presence of a pleural effusion, and a bit of lung tissue can be seen towards the left side of the screen floating in fluid. In addition, there are THREE shadows evident, each from a different source. Can you spot them?

So let’s take these one at a time, with labels:

Shadow A

Is the easiest one. It extends almost from the first pixel at the top of the screen down to the far field. We can’t even see the characteristic echotexture of skin or subcutaneous tissue in the near field. There’s no contact here between the transducer and skin, possibly due to:

• the probe not touching at all
• clothing or an EKG lead getting in the way
• not enough gel (the novice’s answer to everything but sometimes still true)

Shadow B

The most interesting one of the bunch. Probably two major factors at work here. First, this section of diaphragm is a particularly bright reflector so it can create a shadow behind it due to the sheer amount of reflection occurring. Second, the density difference between the diaphragm and pleural effusion is creating a refraction artifact, often referred to as an edge artifact. Beams of sound which were roughly parallel as they struck this interface get bent at different angles based on whether they hit the dense diaphragm or the less dense fluid. The space in between the formerly tightly spaced beams is displayed as blackness, or the absence of returning echoes.

Shadow C

That’s a rib shadow. Did you know that ribs grow back if you remove them?

This young healthy woman presented in her first trimester of pregnancy with lower abdominal pain and vaginal bleeding. She had diffuse abdominal tenderness and was mildly tachycardic with a normal blood pressure. After IV access was established, labs and blood bank sample were sent, and the following ultrasound of the right upper quadrant was obtained:

So there’s a bit of free fluid in Morison’s pouch. Can we make it more evident for the kids in the back row? The next image was taken with the patient in Trendelenberg position:

That made a pretty big difference.

In this sagittal view of the uterus the bladder is visible to the screen right; there is free fluid in the pelvis just to the left of this, and it can be seen to move with probe pressure on the lower abdomen.

Thus a diagnosis of ruptured ectopic pregnancy was strongly suspected, and the patient underwent emergency laparoscopy with the obstetrics service.

Check out our pelvic ultrasound and FAST tutorials for more details on performing these assessments.

This patient presented with diffuse abdominal pain, tachycardia, and peritonitis on physical examination. A FAST exam was performed to assess for free intraperitoneal fluid, and the following view of was obtained transversely in the pelvis.

First, just look at the still image and make your best guess. Then press play:

Did the large anechoic structure in the near field look like the bladder? Or was it the anechoic area in the far field? The operator was thrown off a bit by the complex echoes within the anterior structure. Remember the bladder is going to conform to the shape of the pelvis as it enlarges, so it will take on a characteristic square/trapezoidal shape in transverse orientation. But for the same reasons free fluid will take the same shape. Through the sweep from cranial to caudal you’ll notice two fluid collections; the anterior one seemed to have much more internal echo and debris. Don’t assume that’s the peritoneal fluid- urine can also look that way.

This was the sample obtained when a Foley catheter was inserted into the bladder:

This definitely looked (and smelled) better sonographically.

Here is the longitudinal (sagittal) view through the pelvis:

As usual, the sagittal view gives a better overview of the anatomy of the pelvis. When using the transverse view of the pelvis, you can miss small amounts of pelvic fluid more easily, confuse fluid collections for the bladder, and make incorrect assumptions. Just more support for the sonographic dogma of imaging everything in two planes.

Case resolution:

CT scan confirmed free intraperitoneal fluid but no free air or other signs of bowel perforation. The hemoglobin was stable through several assessments. The patient had an obvious urinary tract infection and renal failure on laboratory evaluation. Thus the fluid was thought to be new onset of ascites in the setting of urosepsis and mult-organ dysfunction.

Tips:

• Always image anatomy in at least two planes, and fan through anything that isn’t moving.
• Rethink assumptions when the anatomy doesn’t look as it should. For example, an oddly-shaped or highly echoic bladder may not be bladder at all, or it might just be an abnormal bladder.
• ALWAYS clean the machine and put it back where you found it when you are done.

I had to throw that in there, sorry.

Patient with history of hypertension presents periumbilical abdominal pain radiating to the back. Minimal abdominal tenderness, no rebound or guarding, though  a pulsatile mass is felt.

The following ultrasound is obtained:

As the title suggests, the patient was diagnosed with an abdominal aortic aneurysm and vascular surgery was consulted.

We’re experimenting a bit with the GMEP.org system. It’s a great educational collaborative run by the folks who brought you Life in the Fast Lane. Worth checking out.

As you may know, we have a Vimeo channel with a growing video archive as well. Our goal is to make this site and it’s content as helpful and accessible a possible, so please let us know how we can improve!

With the proliferation of online educational modalities (blogs, educational websites, podcasts, twitter feeds) designed for rapid dissemination and translation of our basic Ultrasound knowledge to the bedsides around the globe, we must occasionally go back to the source – The Scientific Journal.

Listed below are several ultrasound-specific journals.

• Journal of Ultrasound in Medicine
• Cardiovascular Ultrasound
• Ultrasound Quarterly
• Journal of Clinical Ultrasound
• Critical Ultrasound Journal

This patient presented with right upper quadrant abdominal pain. There was RUQ tenderness on exam, but no fever, rebound or Murphy sign. A point-of-care ultrasound was performed to assess for signs of cholecystitis and the following image was obtained. This prompted the operator to ask, “What the heck?”

What structures are visible here? How could you differentiate them? More after the break!

As with most ultrasound examinations, fanning through the entire target structure is the best way to appreciate the three-dimensional anatomy and avoid confusion. Here the operator was visualizing the gallbladder as they’d hoped, but the inferior vena cava and aorta photo-bombed their image, causing some confusion.

GB from Sinai EM Ultrasound on Vimeo.

Looking at the video of the gallbladder it is more evident that the aorta and IVC are the culprits, and that we are not dealing with pericholecystic fluid, an aortic dissection, cyst, or some other uncommon pathology. Doppler can be useful in distinguishing vessels in this type of scenario as well. In the image below we can see all the structures labelled, including Gallbladder, IVC, Aorta, and Portal vein.

What about the patient, you ask? Normal assessment of gallbladder, normal labs, improved symptoms after an antacid and turkey sandwich. All’s well that ends well.

The Association of American Medical Colleges (AAMC) has written an article about ultrasound education at the medical school level. In the current edition of their widely distributed publication The Reporter, they describe programs at the University of South Carolina School of Medicine, University of California (Irvine) School of Medicine, and the Mount Sinai School of Medicine.

The article notes,

With rapid advancements in ultrasound technology, such scenarios as this are becoming more commonplace, as a handful of the nation’s medical schools make ultrasound training a standard part of the curriculum. And there is a push to encourage more schools to use ultrasound.

The full article is available here.

To image something which moves, you must remain still. To image something which is still, you must move.

If you think on this long enough, the point is self-evident and requires no explanation. Or, just see some examples below.

We are pretty well adapted to seeing three dimensions at a time. Thus when imaging a moving structure like the heart, we hold the probe in a fixed position to obtain standard views. This allows us to focus on the movement, and cardiac presets optimize temporal resolution at the expense of spatial resolution. We are then seeing two spatial dimensions and one temporal dimension (heart moving in time).

D Shaped Left Ventricle from Sinai EM Ultrasound on Vimeo.

It is very difficult to appreciate the anatomy and function of the heart, for example,  when the probe is moving.

In contrast, imaging the right upper quadrant for fluid in Morison’s pouch requires a slow fan through the liver, diaphragm, and kidney. This allows us to appreciate the entire potential space where fluid can collect. Abdominal imaging is optimized for spatial resolution at the expense of temporal resolution, so be sure to move the probe slowly. Fanning through the entire structure of interest will often reveal pathology which was missed with a single-plane scan. Small gallstones, small amounts of peritoneal or pleural fluid, saccular aneurysms, and other maladies can fool a novice sonographer who isn’t thorough. In this case we are seeing three spatial dimensions.

FAST1 RUQ pos from Sinai EM Ultrasound on Vimeo.

So, keep your audience in mind when you are creating scans. Should you fan through the static anatomy, or let the movement of the structures speak for themselves?

Thoracic sonography is one of the most rapidly growing areas of emergency and critical care ultrasound. One very important emerging indication is to assess for lung consolidation. The characteristic appearance of consolidated lung is very sensitive and specific for pneumonia, but novices should heed some important pitfalls in making the diagnosis.

Special thanks to Jim Tsung, MD, MPH and Brittany Jones, MD for their tips, videos, and ongoing research in this important field! For further reading on this topic, please see this article.

Pitfall #1 – confusing thymus for a consolidation

Normal thymus in sagittal view:

Thymus (top half of screen) and heart (bottom right). Don’t confuse thymus for lung consolidation. Note there are no air bronchograms, but thymus has a faint speckled appearance.

Pitfall #2 – mistaking spleen for consolidation.

Left lower chest- sagittal view:

Pitfall #3- missing pleural effusion

Here are a few examples to refresh your memory.

Left pleural effusion:

Identify:

• Pleural effusion (anechoic wedge just beneath ribs and pleura)
• Lung
• Diaphragm
• Spleen
• Air in stomach

Do not confuse spleen and air in stomach for pneumonia.

Right pleural effusion:

Identify:

• Pleural effusion
• Lung
• Diaphragm
• Liver

What’s abnormal in this image?

Here’s a hint.  Here is an example of normal.

When evaluating for possible elevation in intracranial pressure, it has been shown that optic nerve sheath diameter (ONSD) measurements correlate with elevated intracranial pressures.(1,2)  The optic nerve attaches to the globe posteriorly and is wrapped in a sheath that contains cerebral spinal fluid.  The optic nerve sheath is contiguous with the dura mater and has a trabeculated arachnoid space through which cerebrospinal fluid slowly percolates.

ONSD Normal Ranges

The ONSD is measured 3 mm posterior to the globe for both eyes.  A position of 3 mm behind the globe is recommended because the ultrasound contrast is greatest.  It is best to average two measurements of each eye.  An average ONSD greater than 5 mm is considered abnormal and elevated intracranial pressure should be suspected.

ONSD Measurement

Crescent Sign

In severe cases of elevated ICP, one can see an echolucent circle within the optic nerve sheath separating the sheath from the nerve due to increased subarachnoid fluid surrounding the optic nerve.  Ophthalmologists refer to this as the crescent sign.

 The Case

40 yo female patient presents with several months of frontal headache associated with photophobia and blurry vision.  Symptoms have gotten much worse over the last few days and she has had difficulty reading and watching TV because of her visual symptoms.  She denies fevers, chills, nausea, vomiting, or focal weakness.   Pt is hypertensive 170/100.  Her vital signs are otherwise normal.

• Visual acuity - 20/30 OD, 20/70 OS
• CT head is normal
• Bedside point of care ultrasound

papilledema cropped from Sinai EM Ultrasound on Vimeo.

Papilledema 2 cropped from Sinai EM Ultrasound on Vimeo.

This patient had enlarged ONSD (measurements were 6 mm bilaterally) as well as papilledema(arrow).

Arrow notes papilledema

Lumbar puncture was performed.  Opening pressure was 44.  30 cc’s of CSF was drained and the closing pressure was 11.  The patient’s headache and visual symptoms improved .  She was started on acetazolamide and admitted to the neurology service.  MRI brain prior to lumbar puncture showed posterior scleral flattening bilaterally with protrusion of the optic nerve in the the globes bilaterally consistent with increased ICP.

This patient’s papilledema and increased ONSD correlated with a markedly increased opening pressure during lumbar puncture and suggests that ocular ultrasound may play a role in the ED management of patients with suspected pseudotumor cerebri.

Pseudotumor cerebri

Elevated intracranial pressure in the abscence of intracranial mass lesion.  Most common in young, over weight women. If the diagnosis is missed, persistently elevated intracranial pressure can lead to optic atrophy and blindness.

Treatment

• Lumbar puncture to drain CSF to a normal opening pressure.
• Medical:  Diomox (acetazolamide), high dose steroids
• Surgical : Optic nerve sheath fenestration, VP shunt

Summary

The ability to diagnose papilledema using bedside sonography is useful to emergency physicians, as many non-ophthalmologist clinicians do not feel confident in their ability to perform an accurate nondilated fundoscopic examination. (3)  Ultrasound provides a useful alternative means of determining the presence or absence of papilledema in a patient in whom fundoscopy cannot be adequately performed.

[1] Geeraerts T, Launey Y, Martin L, et al. Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury. Intensive Care Med 2007;33(10):1704-11 [electronic publication 2007 Aug 1]. PMID: 17668184

[2] Kimberly HH, Shah S, Marill K, Noble V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med 2008;15(2):201-4. PMID: 18275454

[3] Wu EH, Fagan MJ, Reinert SE, Diaz JA. Self-confidence in and perceived utility of the physical examination: a comparison of medical students, residents, and faculty internists. J Gen Intern Med 2007;22 (12):1725-30 [electronic publication 2007 Oct 6].  PMID: 17922165

It truly is the year of ultrasound — and it isn’t even 2013 yet.  Groundbreaking article on lung ultrasound by our Jim Tsung who found point of care ultrasound to be 86% sensitive and 89% specific in detecting pneumonia up to age 21.  ePub is available ahead of print in JAMA’s Archives of Pediatric and Adolescent Medicine.

Time to say goodbye to ionizing radiation!

Prospective Evaluation of Point-of-Care Ultrasonography for the Diagnosis of Pneumonia in Children and Young Adults

This core didactic session recap is devoted to renal ultrasound. Point-of-care ultrasound uses focused clinical questions to guide management, and our didactic session use focused clinical questions to guide discussions of key literature.

Discussants Vincent Roddy and Phillip Andrus led our group through a series of questions which bring the relevance of renal sonography home.

1. Can the degree of hydronephrosis predict stone size?

In an word, yes. In a retrospective study of 177 patients with documented stones on CT scans, ultrasonographers blinded to the CT results were able to predict stone size (>5mm or <5mm) based on the degree of hydronephrosis observed (1).

Hydronephrosis was defined as mild, moderate, severe

1. Mild: Enlargement of calices with preservation of renal papillae
2. Moderate: Rounding of calices with obliteration of renal papillae
3. Severe: Caliceal ballooning with cortical thinning

Results:

Increasing degree of hydro associated with increasing proportion of ureteral calculi > 5mm (p < 0.001)
Take-home points:

• Stone size is an important predictor of stone passage and clinical outcome; < 5mm likely to pass regardless of location
• Current guidelines recommend triage of “medical expulsion therapy” for calculi between 5 and 10 mm; > 10mm often require surgical removal
• Ultrasound sensitivity for detection of stones greater than 5mm is poor. With severe hydro over one-third had stones over 5mm and one third of THAT group had caliculi larger than 10mm (2)

References:

1. Goertz JK, Lotterman S. Can the degree od hydronephrosis on US predict kidney stone size? Am J Emerg Med 2010; 28:813-6.
2. Preminger GM, Tiselius HG, Assimos DG, et al. 2007 guideline for the mgmt of ureteral calcul. J Urol 2007; 178:2418-34.

2. Should the bladder be included in the renal scan?

Yes – rapid ED renal ultrasound including images of the bladder might exclude distal obstruction and allows clinicians to focus on other diagnoses (1).

Ultrasound of the bladder also allows for the evaluation of the presence of “ureteral jets.”  Although clinically utility is debatable, a unilaterally abnormal ureteral jet can be suggestive of high-grade obstruction on the ipsilateral body side.  Ultrasound is useful in making this determination, though it is limited in its ability to determine stone location.  It is important to note that  normal ureteral jets cannot be used to exclude a diagnosis of renal colic.  (2).

References:

1. Wakins S, Bowra J. Validation of EP Ultrasound in Diagnosing hydronephrosis in ureteric colic. Emergency Medicine Australasia (2007) 19, 188-195.
2. Sheafor D, Hertzberg B, et al. Nonenchanced Helical CT and US in the Emergency Evaluation of Patients with Renal Colic.

3. Can Emergency Physicians accurately diagnosis hydroneprhosis on bedside ultrasonography?

Yes, numerous studies have documented that ultrasound can accurately predict the degree of hydronephrosis as compared to that on CT scans (1-2) and that the degree of hydronephrosis is related to stone size (3).

References:

1. Gaspari RJ, Horst K. Emergency Ultrasound and urinalysis in the evaluation of flank pain. Acad Emer Med 2005; 12:1180-4.
2.  Watkins S, Bowra J, Sharma P, Holdgate A, et el. Validation of EP ultrasound in diagnosing hydronephrosis in ureteric colic. Emerg Med Australas 2007; 19:188-95.
3. Goertz JK, Lotterman S. Can the degree od hydronephrosis on US predict kidney stone size? Am J Emerg Med 2010; 28:813-6.

Were looking forward to the first citywide critical care ultrasound meeting. The idea for this gathering grew out of discussions between ED and ICU folks interested in critical care ultrasound who wanted to share experiences, interesting cases and ongoing research that would benefit from multicenter study.

Date: January 3, 2013
Time: 5pm
Location: 3 E 101st Street, Second Floor Emergency Medicine Conference Room New York, NY

We already know it is helpful to use ultrasound to guide placement of central venous catheters.

How can we use ultrasound to help confirm proper placement of an internal jugular catheter?

There are several methods which have been described:

• Visualize the needle entering the vein (optimally in the long axis)
• Visualize the guide wire in the vein
• Visualize the tip of the triple lumen catheter in the right atrium, then pull back 2 cm
• Bubble test (more on this below)

In addition there are non-ultrasound-related methods to confirm placement (but who cares about those?):

• Chest x-ray
• Blood gas drawn through central venous catheter port
• Pressure transduction (quantitative- manometry)
• Pressure transduction (qualitative- attach IV tubing and check height of blood column)

So let’s get back to that bubble test. In order to confirm that the catheter has been placed in the superior vena cava, inject 5-10 cc normal saline through the catheter while visualizing the right heart on a subxiphoid 4-chamber view.  When done right should look something like this :

Saline flush right heart from Sinai EM Ultrasound on Vimeo.

So this is a neat trick after the catheter is in, but the horse is out of the barn at that point. Ideally you should confirm proper venous placement prior to dilating the vessel and placing the central line. You could do this while the needle is in the vessel, but that’s a bit unstable. Instead consider using the long angiocatheter found in most central line kits to puncture the internal jugular vein.

After the flash (and ultrasound confirmation of venous puncture) advance the catheter and remove the needle. You then have an angiocatheter in the central venous system, which can be used for manometry, blood gas analysis, or the saline push necessary for the bubble test. Some people have used this angiocatheter during ACLS situations to administer a few doses of code medications in a shorter time than it would take to complete a “full” central line.

Once proper venous placement is confirmed, you can advance the guide wire through the angiocatheter and continue the procedure as normal.

For a great overview of central venous catheterization, check out this post by Haru Okuda and Scott Weingart at EMCrit.org.

Further Reading

Prekker ME, Chang R, Cole JB, Reardon R.  “Rapid confirmation of central venous catheter placement using an ultrasonographic “Bubble Test.” Acad Emerg Med 2010;17(7):e85-6. (PMID: 20653578)

A prior post discussed the optimal imaging angle for 2D scanning.

Quick quiz: what is that angle?
45 degrees
90 degrees
180 degrees
360 degrees

In this post we’ll illustrate the optimal imaging angle for Doppler evaluation. Let’s start with basic Doppler physics.
Where to police officers situate themselves to aim a radar gun at speeding cars?

The maximal Doppler shift will be seen at 180 degrees. In fact at the instant the car passes the officer, (90 degrees) there will be zero Doppler shift. At that instant there is no movement between the object and the listener. So they aim the gun directly at the oncoming traffic, so the direction of their beam is parallel to the direction of [traffic] flow.

The image below illustrates Doppler shift of ultrasound reflected off a red blood cell:

1. Top: A normal ultrasound wave
2. Middle: Doppler shift reflected off the RBC moving toward the transducer (thus increasing the frequency of the returning wave)
3. Bottom: Doppler shift reflected off the RBC moving away from the transducer (thus decreasing the frequency of the returning wave).

Thanks to equipmentexplained.com for the image. Imaging at 180 degrees is impractical for diagnostic ultrasound, since the optimal B-mode imaging angle is 90 degrees. Therefore, most authorities recommend an imaging angle between 45-60 degrees for Doppler ultrasound imaging . If you are imaging a vascular structure at 90 degrees and getting no Doppler signal, try lowering your angle.

Is ultrasound the stethoscope of the future? Is it an extension of the physical examination? Will it replace the physical exam?

No.

Point-of-care ultrasound is a diagnostic test. It is a rapid, bedside, noninvasive, accurate, diagnostic test, but still a diagnostic test. It can certainly augment data obtained through physical examination and medical interviews, and adds to information obtained by blood assays and radiology studies.

It is performed using FDA-approved medical devices by clinicians with specialized training. Images used for medical decision-making may be archived and shared with colleagues from multiple specialties. Quality assurance programs improve clinician accuracy and accountability. These are not physical examination characteristics. These are qualities of good diagnostic tests.

There is and will continue to be debate about this issue. Whether we think about point-of-care ultrasound as a diagnostic test or part of the physical examination has ramifications for training, documentation, archiving, and billing.

We recommend checking the guidelines relevant to your specialty and making up your own mind on this issue. In either camp some things remain constant: train well and use ultrasound to enhance the care you provide your patients.

We previously reported on AIUM’s Ultrasound First initiative back in March. Since then a number of helpful articles have been published in the Journal of Ultrasound in Medicine, each highlighting the utility of ultrasound as the primary imaging modality.

Thus far, topics include:

Sonography in Postmenopausal Bleeding – Steven R. Goldstein, MD

Think Ultrasound When Evaluating for Pneumothorax – Vicki E. Noble, MD

Sonography Should Be the First Imaging Examination Done to Evaluate Patients With Suspected Endometriosis – Beryl R. Benacerraf, MD, and Yvette Groszmann, MD

Sonography of Adenomyosis – Khaled Sakhel, MD, and Alfred Abuhamad, MD

Lung Ultrasound in Evaluation of Pneumonia – Michael Blaivas, MD

Ultrasound-Guided Interscalene Blocks – Andrew Gorlin, MD, and Lisa Warren, MD

Sonography for Surveillance of Patients With Crohn Disease – Kerri L. Novak, MSc, MD, FRCPC, and Stephanie R. Wilson, MD, FRCPC

Sonography as the First Line of Evaluation in Children With Suspected Acute Appendicitis – Leann E. Linam, MD, and Martha Munden, MD

Shoulder Sonography: Why We Do It – Sharlene A. Teefey, MD

Sonographically Guided Enema for Intussusception Reduction: A Safer Alternative to Fluoroscopy – Thomas Ray S. Sanchez, MD, Aaron Potnick, MD, Joy L. Graf, MD, Lisa P. Abramson, MD and Chirag V. Patel, MD

Sonography First for Subcutaneous Abscess and Cellulitis Evaluation – Srikar Adhikari, MD, RDMS, and Michael Blaivas, MD

Sonography in the Treatment of Calcific Tendinitis of the Rotator Cuff – Gregory R. Saboeiro

More articles on best evidence are forthcoming- please check out Ultrasoundfirst.org for more information!

On November 11-12, AIUM will host its first Ultrasound First Forum in New York City.

Many new developments in ultrasound were demonstrated at the ACEP conference in Denver this week. Since airway management rivals ultrasound as my academic interest, I’d like to focus for a moment on an intubating device I saw demonstrated at an ultrasound vendor booth.  I’ve seen lots of organs on my ultrasound screen- hearts, gallbladders, eyeballs, prostates. I’ve even seen airway structures, but not like this:

The VividTrac is a single use, USB video intubation device. It is a channeled blade video laryngoscope similar in concept to the King Vision or the AirTraq Optical Laryngoscope. The channel is designed to pass the endotrachel tube through. This is in contrast to non-channeled video laryngoscopes like the Storz C-MAC or the Verathon Glidescope, where the endotracheal tube is guided with a stylet and not directed through the video device itself.

What is interesting about the Vivid device is it hooks up to a monitor using a standard USB cable. Thus, it can be connected to different types of monitors, PDAs or tablets which accept USB input, or… an ultrasound machine monitor! Theoretically one could use an existing ultrasound machine with a variety of probe types as well as a device like this.

There are many device manufacturers involved in R&D of devices which might lead to a technology convergence. Ultrasound probes, video intubation devices, cardiac monitoring equipment, etc. could all transmit images to a monitor, via wires or wirelessly. Thus, pluripotent monitors could be used with a variety of devices depending on the needs of any given patient. This could increase the amount of information relayed via the monitors, and even what is transmitted to the electronic medical record. Importing vital signs, ultrasound images, EKGs, or other clinical images could all be captured in this way. It will be interesting to see how many other devices can learn to communicate with each other as the technology develops.

As a part of Ultrasound Awareness Month we’d like to let providers of all levels know about membership opportunities with national and international organizations.

They offer an enormous amount of information for providers at all levels; from the first time Sonographer to the Ultrasound Director and offer forums and support for all your Ultrasound-related endeavors.

Please visit the following websites for more information and/or follow them on twitter to interact with them in real time. We have included links to student, resident, or fellow membership options where applicable. Be sure to check out special rates, courses, and benefits in all of these organizations designed tom promote inclusion of providers at all levels!

ACEP US Section (US Section President @GeriaSonoMD)

SAEM US Academy (@SAEMAEUS)

AIUM (@AIUM_Ultrasound)

Winfocus (@Winfocus)

Society of Ultrasound in Medical Education (@SUSMEORG)

And of course…SinaiEM.US

The 9th Edition of Advanced Trauma Life Support(ATLS) has incorporated some important changes, one of which directly impacts the world of point-of-care ultrasound. There is increased emphasis on the FAST examination, and Diagnostic Peritoneal lavage (DPL) is now optional. According to the ATLS 9th Edition Compendium of Changes,

Either DPL or FAST must be taught during the surgical skill station as a method of evaluating the abdomen as a source of hemorrhagic shock

DPL was a required skill station in the ATLS 8th Edition; it is now optional.

Further Reading:

• McKenney M, Lentz K, Nunez D, et al. Can ultrasound replace diagnostic peritoneal lavage in the assessment of blunt trauma? J Trauma. 1994 Sep; 37(3):439-41. (PMID: 8083906)
• Farahmand N, Sirlin CB, Brown MA, Hypotensive patients with blunt abdominal trauma: performance of screening US. Radiology. 2005 May; 235(2):436-43. (PMID: 15798158)

We mostly focus on ultrasound here, but a large part of what we do is information exchange, adult education, and the like. We give a lot of presentations, and many of our faculty are interested in the art of speaking, the aesthetics of presentation design, and adult education.

So from time to time we’ll post on presentation-related topics; I hope you find them as useful as we do.

Slide Sorter View

When I’m polishing a talk, I like to look at the slides in Slide Sorter view. I use PowerPoint; Keynote calls this view Light Table. If you are using Prezi, just close your eyes and spin around 20 times really fast. That’s how your audience feels. Now stop it.

Slide sorter has many uses- right now I want to focus on using it as a final litmus test for how interesting your talk is going to be. If you have crafted an engaging presentation, you’ll be able to tell pretty quickly based on this “big picture” view of your content.

Before

Here’s the slide sorter view of a talk I gave during residency. The topic was cyanide poisoning, but it doesn’t really matter. Do you want to hear this talk? I don’t. Take a minute and imagine what this talk will sound like. If you pull out this slide deck (I’m deliberately using that archaic term), you have lost before you started. You could read this in your best Ben Stein monotone, or bend over and speak the words out of your butt like Ace Ventura. It doesn’t matter. We’ve all seen this type of talk a million times. A resident reads some articles, pastes data into the slides without fully assimilating the information themselves. Then we have to listen to them tell us something we could read for ourselves. The resident (in this case, my past self), has taken a dry topic and kept it dry.

After

In contrast, here’s a talk I recently gave as part of Sinai’s White Coat ceremony day. What was the topic? Again it doesn’t matter. Look at the slides. Are you curious to find out what was said?

What’s that wooden tube? Will the boat catch the submarine? Why is that guy in a bathtub? The visuals here are just a part of the process. Hopefully they are designed to augment what is being said by the speaker. Hopefully there is real content here and it’s not just a bunch of pictures. But at least the speaker and audience are not engaged in a race to read through the words on the slides. That’s a race no one wins.

How to use this

The Slide Sorter test is among the last things I check. It’s like looking at yourself in the mirror as you leave the house. You should already have combed your hair and buttoned your fly by then, but the mirror will let you know before it’s too late. There’s an art and science to slide design, which starts way before this. But this is a simple final check.

Slide Sorter view is also very helpful in rearranging slide order and keeping the threads of your talk together. Garr Reynolds, the presentation zen master, uses Slide Sorter view to storyboard his talks as he builds them.

If you haven’t tried this trick, compare your favorite and your worst talk using this view and see if you can spot any differences.

October is Medical Ultrasound Awareness Month!

Medical Ultrasound Awareness Month is a joint effort of the American Institute of Ultrasound in Medicine (AIUM), American Registry for Diagnostic Medical Sonography (ARDMS), the American Society of Echocardiography (ASE), Cardiovascular Credentialing International (CCI), the Society of Diagnostic Medical Sonography (SDMS), and the Society for Vascular Ultrasound (SVU).

WHAT IS ULTRASOUND?

Ultrasound is any sound at a frequency that is above the range of human hearing. Diagnostic medical ultrasound uses high-frequency sound waves to create images of organs and structures inside the body, and is broken into several subgroups according to the specialized area of the body focused upon by a specific procedure. Ultrasound images of the heart are called echocardiograms, and the procedure is called echocardiography; ultrasound images of most other parts of the body are called sonograms, and the procedure is commonly called sonography. Ultrasound tests looking at blood vessels and blood flow are called noninvasive vascular ultrasound examinations. Unlike many other imaging procedures, ultrasound does not use x rays or other forms of ionizing radiation. An instrument called a transducer is placed against the body, and special gel helps transmit the sound. In most types of diagnostic medical ultrasound examinations, the transducer emits short bursts of sound, which bounce off a structure and return to the transducer. These echoes are processed by a computer, and the images they create are displayed on a monitor.

WHO ARE THE ULTRASOUND PROFESSIONALS INVOLVED IN MY CARE?

Physicians who interpret ultrasound examinations are called sonologists. Although many sonologists perform the tests themselves, they often employ highly skilled professionals called sonographers. These individuals have completed extensive, specialized education in the field of diagnostic medical ultrasound. Sonographers who specialize in cardiac ultrasound are called echocardiographers, and those who specialize in ultrasound of the blood vessels are called vascular technologists.
Although a sonographer may play a critical role in extracting the information necessary to derive a diagnosis, the rendering of a final diagnosis of an ultrasound study is the responsibility of the supervising sonologist.

HOW DO I KNOW IF I AM RECEIVING HIGH-QUALITY ULTRASOUND SERVICES?

Ask whether your sonographer is certified. Certified sonographers have demonstrated that they have specific training, experience, and  knowledge to perform an ultrasound examination safely and accurately. To maintain their certification, sonographers are required to earn  ontinuing medical education credits each year, which helps ensure that they remain up-to-date in ultrasound technology and patient care. Ask whether the ultrasound practice you are visiting is accredited. Facilities that have obtained accreditation have demonstrated competency in every aspect of their ultrasound operations, including the education and training of physicians and sonographers, calibration and maintenance of the ultrasound equipment, document storage, policies for safeguarding patients, and accuracy in diagnosis.

HOW SHOULD DIAGNOSTIC MEDICAL ULTRASOUND BE USED?

Diagnostic medical ultrasound should be used in a prudent manner to provide a medical benefit to the patient. Nonmedical use of ultrasound for psychosocial or entertainment purposes is strongly discouraged. The use of ultrasound only to view a fetus, obtain a picture of a fetus, or determine the fetal sex without a medical indication is inappropriate and contrary to responsible medical practice.

FOR MORE INFORMATION, CONTACT

American Institute of Ultrasound in Medicine (AIUM) • 800-638-5352 • 301-498-4100
American Registry for Diagnostic Medical Sonography (ARDMS) • 301-738-8401
American Society of Echocardiography (ASE) • 919-861-5574
Cardiovascular Credentialing International (CCI) • 800-326-0268
Society of Diagnostic Medical Sonography (SDMS) • 800-229-9506 • 214-473-8057
Society for Vascular Ultrasound (SVU) • 301-459-7550