A 39-year-old man was admitted with severe burns.
On examination, he was noted to be persistently tachycardic.
Investigations:
serum thyroid-stimulating hormone0.2 mU/L (0.4C5.0)
serum free T410.0 pmol/L (10.0C22.0)
serum free T32.5 pmol/L (3.0C7.0)
What is the most appropriate next step in investigation of his thyroid status?
A . radionuclide thyroid uptake scan
B . repeat blood tests after recovery
C . reverse tri-iodothyronine
D . thyroid autoantibodies
E . thyrotrophin-releasing hormone test
Answer: B