Category: POCUS/Imaging

Barium Swallow

This is a test we order a LOT in the NSICU. It’s used to ensure that patients who have had a brain injury and an equivocal bedside swallowing exam are actually safe to swallow. They’re used a lot with another group of patients I see in the SICU a lot too, esophagectomy patients. In that case, it’s less to make sure patients aren’t aspirating and more to make sure their esophageal anastomosis isn’t leaking before they’re allowed to resume eating.

But, we often don’t see the images, just the report. So, this Instagram post from theradiologistpage is really interesting. You can see the anatomy and functional assessment involved in this study. For our Speech Language Pathologist (SLP) colleagues, this is a test they use all the time to help us determine if it’s safe for our patients to eat and what consistency/thickness of liquids are safe.

How to Read a CTA for Pulmonary Embolism

A student of mine emailed me the other day asking if I knew of any good resources for learning to read a CTA of the chest for pulmonary embolism. This is something that I’m not very good at. I try to learn to read my own radiography whenever I can, not to supplant the radiologist, but more because I’m interested in how it’s done. Also, I feel like if I have an idea how to do something myself, it gives me a leg up because I don’t have to sit and wait for the read or at least if I do, I have some idea already what it’s going to say.

I remembered finding a good video once that explained it, so I set to Googling and easily found the video I had remembered watching before. Sarel Gaur is a radiologist who has a really great YouTube channel with videos covering lots of good radiology topics. This particular video covers the basics of reading a CTA for PE. There is a follow-up video here that does a case walk through.

iScan 2022

This post isn’t so much educational or to promote some great #FOAMed educational resources, but is to promote an educational event. I’m going to be an instructor at a POCUS event coming up in May called iScan 2022. This is put on by the Society of Point of Care Ultrasound (SPOCUS) and is a POCUS “competition” aimed at PA and NP students. Why is competition in quotes? Well, because it’s really a teaching event disguised as a contest. It’s a great idea to gamify this sort of education. Students register in teams (solo students will be grouped together into teams or added to existing teams) and will go around to various stations where there will be teaching and contests. But it’s all in fun! And it’s FREE!! (Free POCUS training is like a unicorn!)

This is the 5th year, but the first year I’ll be a part of it and I’m super excited! (I was supposed to do it last year, but couldn’t go due to COVID). It’s May 23rd in Indianapolis, IN. If you’re a PA student, that coincides with the AAPA conference, so you may be in town anyway, why not come learn some POCUS? For information, including a link for registration, can be found here.

NPs, the website is heavy on the PA language, but it’s just as much for you! Historically, it’s pretty PA heavy because of its association with the AAPA conference. But, SPOCUS is specifically interested in growing support among NP students. At least a few of the instructors will be NPs and there will be teams of NPs. So, come represent!

Ultrasound Case: PE

Bedside echo can be very helpful in the diagnosis of pulmonary embolism. There are a number of things to look for including septal bowing, right-heart strain in the form of increased RV size and decreased RV function, McConnell’s sign, and the always exciting clot in transit. Sarah Wolochatiuk is a PGY-4 in Emergency Medicine at the University of Cincinnati just up the road from me. She has a great case presentation on the UC EM blog Taming of the SRU that covers all of this with some great echo images as well.

Estimating Cardiac Output with POCUS

I always love learning new things to do with POCUS and learning new POCUS skills. Pulse wave Doppler is not a mode that I use often and it is on my list of things to practice with. I think there are a lot of really nice benefits of it in the management of critical illness and shock. Now, at first you may have looked at the title of this post and thought, “I know how to do this, EPSS or fractional shortening. But those don’t use PWD? What gives?” Well, E-point Septal Separation (EPSS) and fractional shortening don’t use pulse wave Doppler, they use simple M-Mode. But, they also don’t measure cardiac output, they measure left ventricular ejection fraction (LVEF), and those 2 aren’t the same.

Matt Siuba explains why we want to measure CO as opposed to being content with LVEF in this video from the Zentensivist YouTube Channel. He also explains everything you need to know about pulse wave Doppler (or at least everything you need to know right now) and how to use it to measure the CO. Don’t worry, there is nothing wrong with your ears, the audio is sped up to 1.25x in order to reduce the time of the video to 14 minutes (this is critical care, time is brain! and heart! and…you know, we’re busy!).

Sinus Tachycardia

We see lots of arrhythmias in the ICU, but one that often comes up that isn’t really an arrhythmia is sinus tachycardia. Sinus tach often makes us nervous, and not without good reason, as this echo from Dr Obiajulu Anozie demonstrates. As the heart rate goes up, stroke volume may decrease. Likewise, tachycardia may often be in response to decreased stroke volume as the body attempts to compensate and maintain adequate cardiac output. Sinus tach can often be in response to pain or agitation as well. What do we do about sinus tach? Well, start off by treating potential causes. Pain. Agitation. Hypovolemia. But we very rarely need to treat tachycardia itself. There are cases (as with patients on VV ECMO) where beta blockade is indicated to reduce heart rate, but typically once the potential causes are addressed, nothing else needs to be done. In some cases (as demonstrated below), the tachycardia may in fact be compensatory and by slowing it down, we actually cause harm.

CT Abdomen and Pelvis Anatomy

I love a good visual guide to anatomy. As someone who looks at more than a few CTs of the belly, this is super helpful in making sense of what I’m seeing. Also, as someone who does a fair amount of POCUS exams of the abdomen, it’s also super helpful.

Hampton’s Hump

We all know that CTA is the way to diagnose PE in a patient, but this requires a trip to CT and a large dose of IV contrast. So, there are ways to narrow things down in patients for whom PE is suspected. Most of us are familiar with evaluating right heart strain on bedside echo, and lots of us know that you can identify certain characteristic ECG changes. But, somewhat less well known is the radiographic sign known as Hampton’s Hump. This is a dome-shaped opacification that is most commonly associated with PE, but also can be a sign of pulmonary infarction due to other causes, such as angioinvasive aspergillosis. PE causes a wedge shaped infarct with sparing of the apex due to collateral circulation in the bronchial arteries. This leads to the characteristic rounded shape.

New England Journal of Medicine’s Images in Clinical Medicine series recently featured a nice example of this. This requires a free NEJM Online account to view the entire post (but the free account is well worth your time).

POCUS in the NEJM

I used to say that POCUS was the way of the future, but clearly the future is here. POCUS is nearly ubiquitous in the ED and ICU these days. If you don’t know how to use it, not just for procedures but also for diagnosis and management, then you’re behind. This is why we include a dedicated POCUS curriculum for our critical care APP fellows at UK and why we’re incorporating more and more of it into the curriculum of the ACNP program at Georgetown. The Society of Critical Care Medicine and the Neurocritical Care Society are both actively involved in encouraging ICU providers to become proficient in and use POCUS. The current issue of the New England Journal of Medicine has a nice review of the current state of the art when it comes to POCUS, covering the pros and cons, clinical applications, competency and training, and emerging trends. The paper itself is behind a paywall, but if you have access to any kind of medical library, you should be able to get it through your institution.

Read it here.

POCUS in Shock: the RUSH Exam

POCUS can be an extremely helpful tool in approaching the patient with undifferentiated shock. The RUSH exam (or more properly, the RUSH protocol, it’s actually a set of POCUS exams packed together for efficiency and ease of memory) was developed for use in the ED, but it is equally useful in the ICU. In the original protocol, the exams are done in a specific order based on the likelihood of the cause. However, in the ICU I often adapt it based on what I already know about my patient (in a patient who just had a big belly surgery I might start with the abdomen, for example). Additionally, this exam is a good starting point for novice sonographers as it incorporates lots of different exams and doesn’t require the use of advanced techniques (like M-mode, color, or measurements). Scott Weingart over at EM:CRIT does a nice overview here, including some recent updates from Jacob Avilla from 5-Minute Sono and some good resources.

Here is a card I made for my students to help use the findings from RUSH to differentiate shock states.