A 28-year-old female presents to the clinic complaining of profound fatigue, a constant feeling of cold, and an inability to breastfeed her newborn infant. These symptoms have progressively worsened over the four months since she gave birth. Her delivery was complicated by severe uterine atony resulting in massive postpartum hemorrhage, which required an emergency peripartum hysterectomy and multiple blood transfusions. On physical examination, she appears pale and lethargic. Her blood pressure is 90/60 mm Hg and her pulse is 62/min. Which of the following thyroid function test profiles is most consistent with this patient's current condition?
- Decreased thyroid-stimulating hormone (TSH), decreased free thyroxine (T4)Cevap
- BElevated thyroid-stimulating hormone (TSH), decreased free thyroxine (T4)
- CNormal thyroid-stimulating hormone (TSH), normal free thyroxine (T4)
- DDecreased thyroid-stimulating hormone (TSH), elevated free thyroxine (T4)
- EElevated thyroid-stimulating hormone (TSH), normal free thyroxine (T4)
Cevap
Decreased thyroid-stimulating hormone (TSH), decreased free thyroxine (T4)
The correct answer accurately reflects the laboratory pattern for secondary (central) hypothyroidism. This patient's history of massive postpartum hemorrhage complicated by hypotension, followed by failure to lactate (prolactin deficiency), fatigue (ACTH and TSH deficiency), and cold intolerance, is classic for Sheehan syndrome. Sheehan syndrome involves ischemic necrosis of the anterior pituitary gland due to hypovolemic shock during delivery. Without adequate anterior pituitary function, the secretion of thyroid-stimulating hormone (TSH) falls, resulting in inadequate stimulation of the thyroid gland and a subsequent drop in free thyroxine (T4) levels. Therefore, both TSH and free T4 will be characteristically decreased.
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Anahtar Kavram
Sheehan syndrome causes ischemic necrosis of the anterior pituitary, leading to secondary hypothyroidism characterized by low TSH and low free T4 levels.