I definitely remember learning in medical school that tamponade is a clinical diagnosis but now that I think about it, what exactly does that mean in 2019? I did some reading and I see no strict diagnostic criteria for tamponade. Classic signs include the triad low blood pressure, JVD, muffled heart sounds but it sounds awfully outdated in 2019. (I imagine most large pericardial effusions will have 'muffled' heart sounds, and JVD is not very specific). Obvious tamponade cases are obvious, but it's those borderline cases that I question. What if blood pressure is normal, but JVD and muffled heart sound is present, +/- tachycardia? How many symptoms and signs do you need to call it tamponade? What mix/match of these do you need to call it tamponade?
When I say clinical diagnosis in 2019, I don’t mean Beck’s triad. I use a mixture of clinical and echocardiographic signs to gauge the overall gestalt.
Not having tachycardia is a huge indicator
against a diagnosis of tamponade. Not having tachycardia (in the absence of conflating factors or medications) means that pt is has enough beat to beat diastolic filling to generate an adequate cardiac output.
While not as sensitive as tachycardia, I do pay attention to the bp. Hypotension is obviously indicative. Normal or borderline normal can go either way. If the pt is HR 120, sweating their a$$ off, looks anxious, dyspneic, then I don’t look at an sbp 102 and think, oh yea pt’s doing great. OTOH, lying in bed, hr 85, sbp 110, huge pericardial effusion- I’m not that concerned. BP is still a tricky one because you don’t want to misinterpret a high SVR/low CO/normalish MAP scenario incorrectly. So in addition to bp, is the pt mentating ok, warm extremities, good cap refill, making urine, normal lactate etc.
With echo, three things I need to see to support my clinical diagnosis:
IVC plethora- if you have a 1.2 cm ivc that’s collapsing wildly with sniffing, it ain’t tamponade
RV diastolic impingement/collapse - a sensitive and specific sign of impending badness
Mitral inflow velocity or vti variation- not as sensitive but I’ll certainly pay attention to 25% peak to trough variations
Without getting more details on your pt I can’t really tell you what I think, but what I wrote above is the general way I think about whether I need to escalate things.