Find in Library

Nonthyroidal illness (NTIs) can be described as abnormal findings on thyroid function tests that occur in the setting of a nonthyroidal illness (NTI) without preexisting hypothalamic-pituitary and thyroid gland dysfunction. After recovery from an NTI, these thyroid function test result abnormalities should be completely reversible. Multiple alterations in serum thyroid function test findings have been recognized in patients with a wide variety of NTI without evidence of preexisting thyroid or hypothalamic-pituitary disease. The most prominent alterations are low serum triiodothyronine (T3) and elevated reverse T3 (rT3), leading to the general term low T3 syndrome. Thyroid-stimulating hormone (TSH), thyroxine (T4), and free T4 also are affected in variable degrees based on the severity and duration of the NTI. It cannot diagnosed NTIs only by measure one thyroid hormone. As the severity of the NTI increases, both serum T3 and T4 levels drop and gradually normalize as the patient recovers. It's still be an argument for administration of replacement T3 and T4 hormone in patients with NTIS. However, it is impossible to be certain at this time that it is beneficial to replace hormone, or whether this could be harmful. Only a prospective study will be adequate to prove this point, and probably this would need to involve hundreds of patients. Ongoing studies document the beneficial effects of replacement of other hormones in these acutely and severely ill patients.