Post-CABG Hypotension ("We're gonna need a bigger boat!")

Post-CABG Hypotension ("We're gonna need a bigger boat!")

Hey everyone!

We have a new post from our CCM POCUS Fellow, Mark Andreae, MD! We have a different type of teaching point for this case, so be sure to share your thoughts and see the results.

Here is the case stem:
50’s patient with history of ischemic cardiomyopathy POD3 s/p 4 vessel CABG. Condition C called for hypotension. BP 77/49, HR 89. Has felt constitutionally unwell throughout the day. He is pale and cool on exam. You place an arterial line - MAP 55-65 with large pulse pressure variation. You obtain these view on point of care ultrasound.

• What are the structures labeled in the 1st image? (A, B, C, D)
• What is your next step in management?

We will post the results in 1 week, so comment on your thoughts!

-Christopher

Tags: 
POCUS, CABG, tamponade, pericardial effusion, limitations, consultative eho, TTE

 

Comments (5)

Faraaz Shah
says:

1- A: RV; B: LA; C: LV; D: LVOT
2- Patient likely in shock, ultrasound images to me are concerning for an underfilled RV with some echogenicity in the parasternal short axis and a hypokinetic LV. I would call CT surg, possibly concerned about an acute valvular insufficiency.

Ben Smith
says:

Predictably tough windows in a post cabg patient but I think B - pericardial fluid, C - LV, D - LA, and A - ? maybe RV or LVOT. Mitral inflow velocities in last image seem c/w tamponade physiology. Next steps are call CTS for return to OR for evacuation.

Timothy Kaselitz
says:

This is a great case! You really need to focus on what all of the clips are telling you in sum rather than focusing on any one clip. Here are a couple clues to generate more discussion:

1. Increased echogenicity seen in the RVOT on the PLAX view does not necessarily represent thrombus. A similar finding can also be seen with rapid infusion of intravenous fluids and as spontaneous echo contrast or "smoke" in a low flow state.
2. The doppler signal of the mitral inflow is revealing something very concerning that should significantly narrow the differential diagnosis.
3. Don't just focus on the images...Dr. Schott gave you some important information in the vignette. It is critical to interpret the images within the clinical context.

Susan Graff
says:

Dr. Kaselitz, would you be able to elaborate on why the doppler signal of the mitral flow significantly narrows the ddx, or provide a resource that would explain this? I haven't had the opportunity to take the second part of the POCUS course on advanced cardiac imaging, so this point may just be beyond my knowledge base. Thank you!

Christopher
says:

All,

Thank you for the comments. This case was meant to highlight a very important point for POCUS. You need to be aware of the limitations of the devices you are using and your own skills with this technology. Too often, early learners lean into what they believe they may be seeing on POCUS to rule in/out diagnosis. However, one of the most important stages of learning, in general, is to be able to recognize one’s own limitations.

This case does well to demonstrate that. The POCUS operator did not feel comfortable that the POCUS images could rule out a pericardial effusion in this patient, given the clinical situation & findings. Thus, an emergent consultative TTE was ordered. I have provided the images they were able to obtain (now included in this thread's images/clips). Please note the difference in image quality.

With these clips/images, it became much more apparent this patient HAD a pericardial effusion causing tamponade physiology. It’s much more clear that there’s a large echogenic posterior pericardial effusion with LA compression The patient was taken to the OR where 500 cc’s of blood clot in the posterior pericardium were removed with reported immediate improvement in hemodynamics.

Per the operator: “You don’t just get a different operator/interpreter with a consultative echo - you get a different machine. Probably worth remembering in a case like this with limited views, but a critical diagnosis to exclude. Just as Quint said in Jaws 1, ‘we’re gonna’ need a bigger boat’.”

Moving forward, we will plan to include not only “textbook” findings, but other cases to help you learn to recognize limitations in POCUS.

As always, if you have a POCUS case to share, please reach out and let me know!

-Christopher

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