Alterations in neuroendocrine axes in brain-dead patients.

Abstract

To identify changes in anterior pituitary gland hormone levels in brain-dead patients and alterations in free triiodothyronine (fT3), free thyroxine, cortisol, testosterone, and estradiol levels. Ten postmenopausal women and 22 men with brain death (BD) were included. Thefirst blood sample for determination of hormones (pre-BD) was collected when the clinician observed the first signs of BD. The second blood sample (BD day) was drawn after BD certification. Female patients exhibited lower follicle-stimulating hormoneand prolactin levels pre-BD and luteinizing hormone, follicle-stimulating hormone, and prolactin levels on BD day than the age-matched controls. Male patients' sex hormone levels were similar to those of the age-matched controls, except for testosterone levels, which were low in both consecutive measurements. All gonadotropins and prolactin levels were above the tests' lower detection limits (LDLs), except for one male patient with gonadotropin levels below the LDLs of the tests. Estradiol levels in both sexes ranged from normal to elevated. FT3 levels were significantly decreased in the two measurements. Thyroid-stimulating hormone (TSH)levels were low in eight patients and all low TSH levels were above the test's LDL. The remaining patients had normal or elevated TSH levels. The median adrenocorticotropic hormone (ACTH) and cortisol levels were within normal limits. All cortisol and ACTH levels were above the tests' LDLs, except for one patient with ACTH levels below the LDL in both measurements. This study supports the hypothesis that the anterior pituitary gland continues to function in the brain-dead state.