A 74 y/o F with pmhx of metastatic breast cancer, IDDM, HTN presents after a syncopal episode. The patient notes that for the past 2-3 days she has been experiencing some lightheadedness and shortness of breath with exertion. She is presently undergoing chemotherapy (I'd throw in some random chemo drus here, but lets face it, we wouldn't know them anyways...) and radiation. She notes that she hasn't been eating/drinking very well. She denies fever, cough, hemoptysis, leg pain/swelling. She has mild nausea but no abdominal pain.
As you peek up at the monitor, you note that the patient’s HR is ~ 135 and her BP is 88/56. Her O2 saturation is 99% and the nurse told you that she was
afebrile. Taking a look at this patient,
she looks ill-appearing and anxious. Her
extremities are cool to touch. You
quickly decide that Room 33 might not be the best place to manage this patient and
that she would be better served in a RESUS station. As you wheel the patient to RESUS, you are
trying to organize a mental game plan.
You grab a quick accucheck (remembering that your pt is an
insulin-dependent diabetic) which comes back normal at 115mg/dL. You are appropriately concerned about this
patient and feel the need to evaluate her for life-threatening pathologies such
as pulmonary embolism, cardiac tamponade, pneumothorax, and large malignant
pleural effusions. Wouldn’t it be nice
if there were a bedside tool that could help you quickly assess the patient for
the aforementioned “can’t miss” diagnoses.
I think you know where I am going, might be time to…CONSIDER
THE PROBE. I would strongly argue that
for a hemodynamically unstable patient, Point-of-care ultrasound should be the
initial tool utilized to guide workup in a dyspneic patient. You help your RESUS nurse get your patient “plugged in” and
pull in an ultrasound machine to perform a quick ECHO to guide your
decision-making. You grab a couple quick
still images that get you more worried:
https://emedicine.medscape.com/article/80602-overview
Diagnosing a patient with a pericardial effusion is nice,
but what value does it serve us as emergency medicine physicians? In this hypotensive patient with an
impressive pericardial effusion at a quick glance, we need to get moving. GET FLUIDS HANGING (if they aren’t already!) and
then start scurrying around to gather a pericardiocentesis kit or (let’s face
it) perhaps a Cook County makeshift kit (spinal needles tubing, 3 way stop
cock?, get creative…). Prepare yourself
mentally and physically for the prospect that you may need to perform this
rare, life-saving procedure! If you have consultants in-house, GET THEM
INVOLVED! Cardiology should be your
first call, but realize that they may want CardioThoracic surgery involved in this
case.
You have a page out to cardiology, your equipment for an
emergent pericardiocentesis is at the bedside. A 500cc NS bolus is in and the
blood pressure improves to 98/60, HR comes down to 120. You mentally review a recent
ultrasound-college presentation on cardiac tamponade and remember how nice it
is to be succinct but knowledgeable when communicating with your consultants. You go back to the bedside and acquire the
following echo clips so that you might have a more informed discussion with
your consultants.
Now, to review for a minute.
It doesn’t take too much skill as a bedside sonographer to identify a
pericardial effusion. However, it is
much more difficult to assess for tamponade physiology. Early signs of tamponade physiology include a
Dilated IVC with Right Ventricular Diastolic Collapse. This is easier said then done, especially
when considering that these patients are often tachycardic. Use
Apical 4 chamber, Parasternal long or Subxiphoid and take a 5 second clip. When reviewing these clips, assess the R ventricular free wall during diastole by slowing the clip down to
frame by frame progression. By noting
the activity of the mitral (or tricuspid!) valve, you will be able to more
easily separate SYSTOLE (Mitral/Tricuspid valves closed) from DIASTOLE
(mitral/tricuspid valves open). One really
nice trick is to utilize M-mode in a Parasternal Long View. Drop the M mode “plane” through the mitral
valve (in the same location as we do to calculate an EPSS) and view this plane
over time. You should be more easily
able to identify motion of the R ventricular free wall in relation to the
mitral valve to assess for diastolic collapse as shown below:
(zoomed)
The Yellow Circle above
(familiar from measuring EPSS) illustrates the mitral valve snapping open
towards the septal wall (indicating the start of DIASTOLE), while the Blue
rectangle shows the R ventricular free wall collapsing inwards—indicating
tamponade physiology!
After reviewing your bedside
ECHO clips (above), cardiology agrees with your interpretation (R ventricular
diastolic collapse indicating cardiac tamponade) and whisks the poatient off to
the operating room for a pericardiocentesis with CT surgery prepared to perform
a window if the pericardiocentesis fails.
Take Home Pearls
1) In a
hypotensive and dyspneic patient, always CONSIDER cardiac tamponade in your
differential diagnosis and then CONSIDER THE PROBE…
2) Once you
have diagnosed the effusion, use POCUS to assess for IVC dilation with RV free
wall collapse during diastole as indicators of tamponade physiology—and a
patient that is more likely to require urgent vs emergent pericardiocentesis.
3) Utilizing
M-mode on PSL view may help you to more precisely identify the movement of the
RV free wall during Diastole vs Systole.
4) Once POCUS
has identified tamponade physiology, prepare yourself (mentally and physically)
to perform a pericardiocentesis while concurrently reaching out to your
consultants.
Sources/Links
Nice intro/discussion through
Dr. Avila’s 5 min sono: http://5minsono.com/tamp/
Really awesome/in depth
videocast from Mike/Matt that delves further into tamponade physiology: http://www.ultrasoundpodcast.com/2013/11/pericardial-tamponade-learn-know-foamed/
As always check out
Introduction to Bedside Ultrasound Ch: 17 (R Heart Pathology) to review this
topic further: https://itunes.apple.com/us/book/introduction-to-bedside-ultrasound/id554196012?mt=11
