A 70-year-old man is admitted to the ICU with severe sepsis secondary to pneumonia. Vital signs show BP 92/58, HR 118, RR 28, temp 39.2°C, SpO2 88%. Thyroid function tests reveal low T3 (60 ng/dL), normal-low T4 (5.2 mcg/dL), and normal-low TSH (1.8 mIU/L). Chest X-ray confirms bilateral infiltrates. He denies prior thyroid disease and takes no thyroid medications. Which mechanism best explains these thyroid findings?
- A)Unregulated secretion of TSH by pituitary adenoma
- B)TSH receptor stimulating antibodies
- C)Autoimmune destruction of thyroid follicles
- D)Increased peripheral conversion of T4 to T3
- E)Reduced peripheral conversion of T4 to T3 during severe illnessGABARITO
Explicação
Euthyroid sick syndrome occurs during severe systemic illness and is characterized by reduced peripheral conversion of T4 to T3, leading to low T3 levels. TSH is usually normal or low, and the thyroid gland is not primarily diseased. Recognition prevents misdi... Ver explicação completa e trilha adaptativa →