SonoTips & Tricks: The FAST scan: The Cardiac views #FOAMed

Finishing the ultrasound QA sessions that we do every week at Stanford, I was reminded about how bedside ultrasound is a tool that helps when resources were limited. If you hadn’t heard, there was an Asiana Airlines plane crash at San Francisco International Airport with over 180 patients requiring medical care, 55+ of which came to Stanford. Luckily, we just added 4 new SonoSite EDGE ultrasound machines to our 4 MTurbos and 3 GE Vscan systems the week before – and they sure were used well! The FAST scan was used as a screening tool and to help prioritize those who would go to the CT scanner. Once, again, it is important to know how to do it and do it well.  Our latest insert in the ACEP Ultrasound Section newsletter is below – on the FAST scan – the Cardiac sections. The prior entry was on the FAST scan: The Upper Quadrants ( go here. ) – And Ultrasound Podcast recorded with Cliff Reid about it this week too!

I’ll start with what I’ve said before: “2013 is the YEAR OF ULTRASOUND – and for good reason – there are only a few tools that give us such immediate information that can save a life. The ACEP US Section is the go-to site for everything you want to know about starting an US program, credentialing in ultrasound, the policies and politics, and is the home of SonoGuide - an amazing educational resource for bedside ultrasound, and the EMSONO: Ultrasound Test. It is also where we add our entries for their newsletter that goes over tips and tricks, cases, and all things ultrasound in the news. We recently wrote an article for the ACEP Ultrasound Section Newsletter - which is available for all members of the ACEP US Section – and I highly recommend becoming a member – it’s totally worth it.”

It was a TRUE pleasure to record a podcast recently with Dr. Scott Weingart (aka, my hero) on EMCrit (twitter: EMCrit), and writing this article with our ultrasound fellow, Dr. Viveta Lobo, describes some of what was spoken about.

By Viveta Lobo, MD and Laleh Gharahbaghian, MD, FACEP

As discussed in our last entry, the FAST exam is undoubtedly the most widely used bedside ultrasound application used in emergency medicine. Its incorporation in the ATLS revised protocol, the RUSH exam, and several other published protocols, makes it an invaluable screening tool for intra abdominal injury causing hemoperitoneum, cardiac injury with pericardial effusion, and unexplained hypotension.

We will continue our discussion of the FAST scan by reviewing the cardiac views, and relay some tips and tricks for each. Refer to the previous newsletter for tips onscanning the right upper quadrant (RUQ) and left upper quadrant (LUQ).

The Cardiac Views:

The traditional cardiac view obtained as part of the FAST exam is the subxiphoid view. The main focus of this view in the FAST exam is to evaluate for evidence of cardiac injury by evaluating for pericardial effusion and/or cardiac tamponade. The phased array probe is placed in the subxiphoid space medially, applying pressure to go under the xiphoid process and flattening out the probe while aiming caudally.

Tips for the Subxiphoid View: 

TT1 1. Use your liver as an acoustic window. 
TT2
Sound waves will travel through liver to the heart, allowing you to visualize the heart. Often one can even place the probe slightly to the right of the xiphoid process, to allow for better liver visualization, and then adjust your depth to be able to look past the liver to the heart. Without the liver in view, gas scatter will affect your image acquisition.


2. Visualize both the inferior and superior pericardial borders, to completely evaluate for pericardial effusion or, rarely, loculated pericardial effusions. It is possible for one area to have pericardial effusion and not the other. Click Here for a Video.

3. Have the patient take a deep breath and hold it. When you notice that the heart is far from the probe, and you find yourself adjusting your depth to more than 20cm, having your patient take a deep breath will lower the heart closer to the probe, improving visualization. Click Here for a Video.

TT3

Despite the subxiphoid view being the traditional view for the FAST exam, the parasternal long view is becoming more of the ‘go-to’ window to evaluate for pericardial effusion. This may be due to several very relevant clinical factors: You simply cannot get a good subxiphoid view. An injury, foreign body, or abdominal pain does not allow for subxiphoid probe placement/pressure. Or you can differentiate pericardial fluid from pleural fluid in the parasternal long view

Tips for Parasternal Long View:
As far as patient positioning, if you’ve already evaluated the RUQ and LUQ (so as to not affect free fluid evaluation) and the patient is able to turn into a left lateral decubitus position, it will help bring the heart closer to the chest wall for visualization. This can be difficult, or impossible, in trauma patients, so the below tips may help:

TT4 1. Start high and start medial - Place your phased array probe just next to the sternum, starting just under the clavicle. If you don’t see the heart there, slide down a rib space, and fan through that space to find the heart. Continue sliding down rib spaces, until you find it.

2. Slowly change the angle of your probe (up and down) when you’re assessing each rib space as described above. ‘Slowly’ is the key word here. If you’re angling downward too much in a rib space and see the PSL heart, you may need to just slide down a rib space. If that makes the image worse, slide back up.

3. Slowly rotate your probe while keeping the angle described above (clockwise/counterclockwise depending on whether you use the right shoulder or the left hip to direct your probe marker). Rotate until you visualize the longitudinal view of the left side of the heart.

4. Slide your probe medially/laterally only if you need to in order to center the aortic and mitral valves on your screen.

5. Ensure adequate depth in order to distinguish a left sided pleural effusion from a pericardial effusion. This will allow visualization of the descending thoracic aorta seen in its transverse view just deep to the heart, which is your landmark in differentiating pleural effusion from pericardial effusion. Pleural effusion will travel posterior to the aorta while pericardial effusion will travel anterior to it (and possibly circumferentially around the heart).TT5
TT6

TT7Lastly, it can be very difficult in both subxiphoid and parasternal long views to differentiate epicardial fat pad from pericardial effusion. One tip: epicardial fat is seen anteriorly and has echogenicity within it, while pericardial effusion is seen posteriorly or inferiorly and is anechoic, but can travel anteriorly if large enough to become a circumferential pericardial fluid collection. Despite this tip, clinical correlation is needed.

Look out for Part 3 of the FAST Exam: The Pelvis, in the next newsletter. Until next time, happy scanning!

For a set of links to online education in bedside ultrasound, go here. Another post on Social Media in EM Ultrasound and the amazing tools out there to learn it for free, go here.”

References
1. Ma OJ, Mateer JR, Ogata M, et al. Prospective analysis of a rapid trauma ultrasound examination performed by emergency physicians. J Trauma. 1995; 38:879-85.
2. Wherrett LJ, Boulanger BR, McLellan BA, et al. Hypotension after blunt abdominal trauma: the role of emergent abdominal sonography in surgical triage. J Trauma. 1996;41:815-20.
3. Schiavone WA, Ghumrawi BK, Catalano DR, et al. The use of echocardiography in the emergency management of nonpenetraing traumatic cardiac rupture. Ann Emerg Med. 1991;20:1248-50.
4. Rozycki GS, Feliciano DV, Ochsner MG, et al. The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study. J Trauma. 1999;46:543-52.

 

 

 

SonoTutorial: The FAST Part 2b: Left Upper Quadrant – More images that could fool you…

Get ready for some more real cases and, just like the prior post, with images of various sections of the left upper quadrant (as you cannot really have all sections in only one 6 second clip). Just like before, think of what is needed to complete the left upper quadrant view:  read the clinical correlate, see the image, and think about what section of the left upper quadrant view is missing (above the diaphragm, below the diaphragm, between the spleen and superior pole of kidney, between the spleen and inferior pole of kidney, or the paracolic gutter), how the image could be improved, and what the interpretation would be. All are stated below the image as well as the actual diagnosis of that particular patient. And, in case any of the below cases stump you as to why the FAST is negative or why it was done in the first place, recall its indications and…. Don’t forget the FAST limitations. Continue reading

SonoTutorial: The FAST Part 2a: Left Upper Quadrant – Images that could fool you…

Get ready for some cases!!! The images and clips below will be a great review to see how much of the information from the prior post on how to perform a complete left upper quadrant view of the FAST scan you recall, while keeping FAST limitations in mind. Remember, in order to be complete and thorough you must evaluate above the diaphragm, below the diaphragm, around the spleen and superior pole of the kidney, and around the spleen and inferior pole of the kidney, and along the left paracolic gutter –  through slow, deliberate, and full fanning between multiple rib spaces, and adjusting your depth as needed.

The images will appear with a clinical correlation first which may give you a certain level of suspicion. Think about what part of the LUQ scan is missing (as there is very few times when you can get all of the above areas in just one clip or in just one rib space), how would you improve the evaluation (changing position of probe, fan more widely or slowly, depth or gain (brightness) adjustment, etc), and what your interpretation of that image would be (positive or negative for free fluid – or is the image just too technically limited to make a statement on it?)- all while thinking of your level of suspicion of injury given the clinical correlate.

These are all real cases: Continue reading

SonoTutorial: The FAST Part 2: Left Upper Quadrant – being right with the left…

No, this isnt a talk about partisan politics (thankfully!), but something that is even more important that you should know and learn well, that could not only change everyone’s life [like politics thinks it does] (by way of how they manage their patients) but also saves a life (by how quickly you help your diagnoses be made). That’s right fellow blogosphere friends. Listen up!

Our SonoTutorial on The FAST: Right Upper Quadrant (RUQ) week was just the beginning of this review on the FAST scan- the most common application done at the bedside at many institutions, and for good reason. It’s used (as a screening study for intraperitoneal free fluid) for any blunt or penetrating chest/abdomen/back trauma as well as the unexplained hypotensive patient (the RUSH exam). The RUQ is the best area to evaluate for free intraperitoneal fluid of all the FAST views, but don’t think you can just do that view and stop there! It is not 100%, and there are enough times for me to see free fluid in the left upper quadrant (LUQ) that was difficult to see in the RUQ that makes it evident that completing the FAST scan is key! The LUQ is, essentially, the not-so-ugly sister to the RUQ. Continue reading

SonoTutorial: The FAST Part 1b: The Right Upper Quadrant: More images that could fool you

Get ready for some more real cases and, just like the prior post, with images of various sections of the right upper quadrant (as you cannot really have all sections in only one 6 second clip). Just like before, think of what is needed to complete the right upper quadrant view:  read the clinical correlate, see the image, and think about what section of the right upper quadrant view is missing (above the diaphragm, below the diaphragm, between the liver and superior pole of kidney, between the left heptaic edge and inferior pole of kidney at the paracolic gutter), how the image could be improved, and what the interpretation would be. All are stated below the image as well as the actual diagnosis of that particular patient. And, in case any of the below cases stump you as to why the FAST is negative or why it was done in the first place, recall  it’s indications and…. Don’t forget the FAST limitations. Continue reading

SonoTutorial: The FAST Part 1a: The Right Upper Quadrant: Images That Could Fool You

Now the fun starts! The images and clips below will be a great test to see how much of the information from the prior post on how to perform a complete right upper quadrant view of the FAST scan you recall, while keeping it’s limitations in mind. Remember, to be complete and thorough, you must evaluate above the diaphragm, below the diaphragm, around the liver and superior pole of the kidney, and around the left liver edge and inferior pole of the kidney (along the right paracolic gutter) through slow and deliberate full fanning between multiple rib spaces, and adjusting your depth as needed.

Continue reading

SonoTutorial: The FAST Part 1: The right upper quadrant – the right way to do it

The FAST scan (focused assessment with sonography for trauma) is probably the most frequent application of bedside ultrasound with a moderate sensitivity and very high specificity. It is done as part of our trauma evaluation for blunt or penetrating chest/abdomen/back/pelvic trauma as well as in the evaluation of the unexplained hypotensive patient as part of the RUSH protocol and the patient with a possible ruptured ectopic pregnancy.

Continue reading

SonoApp: Lung Ultrasound – The down low of pneumo…with the help of Lichtenstein, of course

Lung ultrasound (aka thoracic US) is one of the currently most popular applications of bedside ultrasound. It was found to be more sensitive and specific than chest XRay for pleural effusion, pulmonary edema, and pneumothorax evaluation (see meta-analysis in Chest here)…. how about them apples?! There have been some recent studies suggesting that in the heat of the moment for trauma patients, the sensitivity may be slightly lower than other studies state, but it is still better than chest Xray! Not only does it take a long time to get that chest Xray done in your ED or in through your ambulatory care practice, but its more expensive than bedside limited ultrasound for the patient as well…. lets not even talk about the radiation (yes, I know, Chest Xray radiation is minimal, but it’s still radiation). The evaluation of the lungs takes no more than 3 minutes, and ultrasound machines can be found in your pocket now (should you want that kind of VERY COOL technology). US machines can also be the size of a laptop with better resolution and multiple probe capabilities – so, needless to say, its easy, portable, fast, and more accurate. Now let’s talk… Continue reading

SonoCase: Motorcycle victim: needs OR! But wait…

So, this case that I just had the other day is an example of an “oldy but goody” reason why bedside ultrasound rocks, especially in the blunt trauma victim with multiple injuries. 40 year-old motorcycle helmeted driver going moderate speed was T-boned by a car and fell onto his left side. He c/o severe left leg pain and mild left lower back pain, with STABLE (and yes, I mean, stable/normal/not worrisome vitals – HR 72, RR 16, BP 148/90, O2 sat 97%RA) with a clear primary trauma survey, and a secondary that revealed a small abrasion on his cheek, no left sided chest wall tenderness, nontender abdomen, no pelvis instability, an obvious deformed open fracture of his left tibia/fibula, and left lower posterior rib cage tenderness without crepitance or bruising. An E-FAST was done… Continue reading

SonoTip: Da Spine Sign: Dont miss that Pleural Effusion on the FAST scan!

I call it “Da Spine Sign” (insert any accent here – trust me, its funny). So, fluid is the lover of ultrasound, right? And air is the enemy. Typically you will not see the spine passed the diaphragm when looking at your RUQ view for your FAST scan in normal patients, but oh when you do, BAM! You know there’s fluid in the thorax. Here’s an image showing exactly that, as well as a little somethin’ somethin’ in the intraperitoneal space… so, don’t forget to look above the diaphragm in your FAST scan views! By the way – it’s also called the V-Line - I like my name better :)