Did she have a T4 test for thryoid? presume she had that test when she was first diagnosed with hypertyhroidism? Are they saying she is not now hyperthryoid? Sounds to me with high heart rate and weight loss she is indeed still hyperthryoid and would have thought her thryoid meds dosage needs adjusting before any further investigations are done. What are they wanting to aneathetise her for? I don't think I'd want to put her under until her thryoid is completely under control.