【用戶】.

【年級】大三上

【評論內容】A. Insulin-induced hypoglycemia test( insulin tolerance test (ITT) )Insulin-induced hypoglycemia, are utilized to evaluate the response to stress, particularly when ACTH deficiency is suspected as the cause. This stress test also is used to establish a diagnosis of growth hormone deficiency.測試方法The ITT involves administration of regular insulin 0.1 U/kg IV (dose should be lower if hypopituitarism is likely) and collection of blood samples at 0, 30, 60, and 120 min for glucose, cortisol, and growth hormone (GH), if also assessing the GH axis. Oral or IVglucose is administered after the patient has achieved symptomatic hypoglycemia (usually glucose <40 mg/dL). A normal response is defined as a cortisol >20 μg/dL and GH >5.1 μg/L. The ITT requires careful clinical monitoring and sequential measurements of glucose. It is contraindicated in patients with coronary disease, cerebrovascular disease, or seizure disorders, which has made the short cosyntropin test the commonly accepted first-line testB. TRH stimulation testA TRH stimulation test involves the intravenous administration of TRH (200 mcg) withmeasurement of serum TSH at baseline and then 20 and 60 minutes after TRHadministration. The normal increment in TSH at 20 minutes is 5 to 30 mU/L, with asubsequent decrease at 60 minutes. Classically, one would expect no serum TSH responseto TRH in patients with pituitary disease and a delayed response in patients withhypothalamic disease. In fact, the response to TRH is highly variable in thesecircumstances, limiting the utility of this test in distinguishing between pituitary andhypothalamic disease as a cause of central hypothyroidism.A TRH stimulation test may be useful in distinguishing nonthyroidal illness fromcentral hypothyroidism due to pituitary disease. Patients with nonthyroidal illness havea blunted nocturnal rise in serum TSH concentrations, but they usually have a normalserum TSH response to TRH.