Thyroid testing in the ED
Thyroid (and other tests, like the reactive protein whose-name-shall-not-be-spoken) come in and out of favour in the ED. In today's results pile were 41 TFTs from the last week - 7 had elevated TSH with normal T4.
Question: What do you think these results mean in a slightly hypotensive elderly patient with AF, but no clear history of other thyroid related symptoms?
TSH13.2 (normal 0.35-4.5), Free thyroxine 20.8 ( normal 10.5-26)
From Dr Ruth Ayling - Clinical Pathologist, Derriford:
"Isolated alterations in serum TSH concentration occur in about 15% of hospital in-patients due to the effect of non-thyroidal illness or drugs. Therefore testing of thyroid function in patients admitted to hospital acutely is not indicated unless specific clinical indications occur."
Interesting that in these samples from last week, 17% were positive....
So what are the indications. Well, clinical suspicion of Myxoedema coma or Thyoid storm, obviously. Beyond that, it's much less clear.
What about new onset AF I hear you all cry? To you I say:
"An abnormal TSH level is common in patients with recent-onset atrial fibrillation. However, clinical thyroid disease is uncommon. Routine TSH screening of patients who have atrial fibrillation has a low yield and may be better applied to those patients at higher risk of having undiagnosed clinical thyroid disease." Arch Intern Med. 1996;156:2221-2224
It turns out that the research around what tests add value in EDs is extensive (try this review or this study), and there are a number of strategies out there to try to minimise over investigation, both for the patient's sake and the trust's balance sheet. It's actually quite interesting. Turns out there are lots of ways to approach the problem. Why not post your ideas below and we'll see if there are others we can try?
For those of you who can't remember what thyroid disease presents like, try the articles below:
I suppose, like every test we do, it comes down to pre-test probability. Sending a battery of tests to the lab hoping something will come back positive is not good medicine. Also, what we "traditionally" ordered (eg TFTs in new Afib) is not always evidence-based and we should be happy to defend our modern approach to colleagues who feel that tests should have been ordered for a particular condition (eg AXR in Q appendicitis, CXR in <i> every </i> chest pain).
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The Derrifoam Blog
Welcome to the Derrifoam blog - interesting pictures, numbers, pitfalls and learning points from the last few weeks. Qualityish CPD made quick and easy.....