D dimer Golly why? Don’t need people getting a CT PE for dimer of 592 and then having to shut down your scanner to clean it....

D-dimer was prognostic in some studies. In some retrospective studies poor outcome correlated with elevated D-dimer. In a study of over 80 deaths 98% had elevated d-dimer at admission. Others argued for D-dimer inclusion as PE may mimic the symptoms of COVID (SOB, tachycardia, CP...) and get missed. I'm not totally sure that I could accurately interpret an elevated d-dimer in a COVID suspect.

Thanks for stimulating this important question Jeff. I was talking to colleagues about this exact thing yesterday while on shift at VGH, and it would be really helpful to have a collective approach on this. Personally, I've always tried to avoid tests that won't influence decision making, and I don't think there is any reason to do any differently now. While many of the tests you have listed have a known percentage of abnormalities in COVID+ patients (such as a 30ish percent proportion of cases with liver enzyme elevations), I'm not sure any of these things influence decision making all that much (even the DDimer correlation). Ultimately all we really need to decide for folks who are presumed positive are whether they are sick enough to be admitted or not (and only those who are admitted will even be tested with our current criteria and confirmed to have COVID)... I had a patient on a shift in the past week who all but certainly had COVID, and in addition to a physical exam and determining my overall clinical sense, all I did on him/her was a CXR. That and his/her O2 sat were enough to confirm that admission wasn't needed despite the presence of respiratory symptoms. Another thing (which I didn't do, but which I've seen talked about as aiding decision making in Italy) is assessment of O2 sat after some mild exertion (walking around with a mask on). I didn't do any other blood tests on my patient, and I'd argue they are not needed unless you feel someone has additional co-morbidity or needs admission. I did give my patient a trial of ventolin by aero-chamber - it subjectively improved things (I didn't do a peak flow) and I sent him/her home with that. I'll be interested in what others have to say, but I'd suggest the theme of our approach (and hopefully we can land on a collective one) is to minimize tests to those that influence decision making, and in doing so minimize cost and staff risk, while maximizing flow and ED efficiency.

Yes. A few of the tests are to both prognosticate the severity of Covid [whether patients need admission] and also to help rule out Covid mimics.: Troponin, D dimer, chest x-ray, CBC with differential.