How Effective Is Dexamethasone for Croup?

The medium-dose dexamethasone inhibition test is performed by the following principles: masculine congenital adrenal hyperplasia, such as patients with 21 hydroxylase deficiency due to cortisol synthesis disorders, ACTH feedback secretion increases, leading to adrenal hyperplasia and adrenal males Increased ketones (increased in urine 17-KS, 17-KGS). The administration of an appropriate amount of exogenous synthetic corticosteroid-dexamethasone to inhibit the excessive release of ACTH will cause the urine 17-KS and 17-KGS levels to decrease.

The medium-dose dexamethasone inhibition test is performed by the following principles: masculine congenital adrenal hyperplasia, such as patients with 21 hydroxylase deficiency due to cortisol synthesis disorders, ACTH feedback secretion increases, leading to adrenal hyperplasia and adrenal males Increased ketones (increased in urine 17-KS, 17-KGS). The administration of an appropriate amount of exogenous synthetic corticosteroid-dexamethasone to inhibit the excessive release of ACTH will cause the urine 17-KS and 17-KGS levels to decrease.

Name

Medium dose dexamethasone inhibition test

category

Renal function

Normal dose of dexamethasone inhibition test

(1) After taking the medicine, 17-KS is positive (can be suppressed) by a decrease of> 50% compared with the control value, which supports the diagnosis of congenital adrenal hyperplasia. (2) The increase of 17-KS caused by adrenocortical adenoma or gonadal disease is not suppressed.

Clinical significance of medium-dose dexamethasone inhibition trial

Abnormal results: congenital adrenal hyperplasia with semi-yin and yang external genitalia, melanin deposition, dehydration, coupled with hyponatremia, hyperkalemia, and metabolic acidosis, elevated serum 17-OHP, urine pregnanetriol (17-OHP urine Fluid metabolites), plasma renin activity and other symptoms. Adrenocortical adenoma or gonadal disease: 1. Adrenocortical adenoma adenoma is usually unilateral and single, and has a thin layer of envelope, which has the phenomenon of compression of surrounding tissues, is the main point of identification. The size is 1-5cm in diameter, the cut surface is yellow, and sometimes it is reddish-brown. Most of the cells are foam-like transparent cells that resemble a band, and are rich in lipids, sometimes composed of eosinophils with low lipid content, or two types. The cells are mixed. Tumor cells are arranged in clumps, separated by a small amount of stroma containing capillaries. Some adenomas are functional and can cause hyperaldosteronism or Cushing syndrome. People to check: Patients with symptoms of congenital adrenal hyperplasia can also be used for patients who need to distinguish between congenital adrenal hyperplasia and adrenocortical adenoma or gonadal disease.

Precautions for medium-dose dexamethasone suppression test

Unsuitable people: temporarily unknown taboo before examination: pay attention to normal diet, pay attention to normal work and rest, to prevent endocrine disorders. Requirements during examination: Actively cooperate with the doctor's requirements.

The above experimental results are susceptible to interference from other components in the urine, such as crystalline and colloidal substances such as protein, sugar, and contrast agent in urine, which can result in higher urine specific gravity results. When interpreting the above experimental results, the effect of temperature should also be considered. Excessive sweating during high temperatures in summer can cause a decrease in urine output and an increase in specific gravity. Conversely, cold climates can have the opposite effect.

Mid-Dose Dexamethasone Inhibition Test Inspection Process

[Methods] (1) Take a 24-hour urine test for 17-KS (and / or 17-KGS) as the control on the first day. (2) Oral dexamethasone 0.75mg, q6h for 5 consecutive days. (3) Collect 24-hour urine test for 17-KS (and / or 17-KGS) on the 3rd and 5th day after taking the drug. [Result analysis] If the patient's 24-hour urine test 17-KS (and / or 17-KGS) control is slightly higher than normal, although dexamethasone inhibition is suppressed below 50%, congenital adrenal hyperplasia can be excluded.

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