Regarding sick euthyroid syndrome (or nonthyroidal illness syndrome) in critically ill patients, which of the following is incorrect?
A. Common to all of the abnormalities in thyroid hormone concentrations seen in critically ill patients is a substantial depression of serum total T 3 levels, which can occur as early as 24 hours after the onset of illness.
B. Serum total T 4 levels may be elevated early in acute illness, as the severity and the duration of the illness increases, serum total T 4 levels decrease into the subnormal range. Decrease in serum TSH levels is also seen.
C. Despite marked decreases in serum total T 4 and T 3 levels in the critically ill patient, the free hormone levels have been reported to be normal or even elevated.
D. Full restoration of thyroid hormone levels to the normal range usually occurs the latest within days of recovery of the illness.
Answer: D
Full recovery, with restoration of thyroid hormone levels to the normal range, may take several months after the patient is discharged from the hospital.
Reference
Irwin and Rippe’s Intensive Care Medicine 5th edition (January 2003): By Richard S., Md. Irwin (Editor), James M., Md. Rippe (Editor), Herbert P. Goodheart By Lippincott Williams & Wilkins Publishers