And the Answer is…
The previous video showed a large pericardial effusion with evidence of tamponade. As it turns out, the patient, when more awake, gives you the history that she had sudden syncope while in her garden and was hypothermic because she passed out in the backyard during a light rain when it was 60 degrees outside and was down for a short time. Workup revealed a painless ascending aortic dissection with hemorrhage into the pericardium, causing tamponade. She went to the OR and did well.
So what does this image show that would indicate tamponade effect from her effusion?
1. RV collapse during diastole. This can be seen in a few ways. You can freeze your image, and scroll back to end diastole when the LV is full, and look to see if the RV has collapsed. You can also place M mode across the RV and LV, and when you see the LV cavity at it’s largest, look to see if the RV free wall is expanded (towards the probe on the 2D image) or collapsing (away from the probe on the 2D image). This is also grossly noted in the “wavy” appearance of the RV free wall that can be seen in most views (remember the old car commercial where the passenger had their arm out the window letting the wind make their arm wave).
2. The RV and LV seem to not be “talking to each other.” Typically, you see the RV and LV contact and expand in unison, however in tamponade, you note they seem to expand and contract on their own. The more scientific term for this is ventricular interdependence. Learn more about it here.
One other window that will help demonstrate evidence of tamponade is shown above, the IVC. With tamponade comes elevated right heart pressures, which are transmitted back to the IVC. In tamponade, the IVC becomes plethoric, and does not collapse normally during inspiration. As you can see, that big fella is not moving.
As with any ultrasound application, you have to put your images together with the clinical picture. There are other things that can cause ventricular collapse or IVC plethora, but in the right setting, you can make this diagnosis and change management early. This particular patient was actually already being treated as sepsis (hypotension, hypothermia, WBC of 14…has to be sepsis, right?). Her hypotension was not responding to fluids and she had been started on dopamine. Instead of going to the ICU and crashing, US helped make the diagnosis, she got her effusion drained and went to the OR, and eventually left the hospital.
This case is another example where point of care US gives you a quick diagnosis, allowing you to make appropriate management decisions and take better care of your patients. Bring the US machine into the room when your patients are hypotensive. You’ll be amazed at what you will find.
2. Nagdev, A; Stone, M. Point-of-care ultrasound evaluation of pericardial effusions: Does this patient have cardiac tamponade? Resuscitation 82 (2011) 671-673.