Alterations in thyroid hormones, cortisol, and catecholamine concentration in patients after orthopedic surgery

Changes in serum and plasma concentrations of thyroid hormones, cortisol, and catecholamines were measured simultaneously in 16 patients undergoing major elective orthopedic surgery. Blood samples were collected preoperatively and at 2, 6, 24, 48, 96, and 168 hr after surgery. A significant decrease in TT3 and FT3 and an increase in rT3 were noted after surgery. TT4 started to decrease 48 hr after surgery whereas FT4 showed no significant change over the same period of time. The concentration of TSH fell progressively after surgery reaching a nadir by Day 7. The concentrations of cortisol were increased markedly throughout the course after surgery. Adrenaline and noradrenaline levels were increased markedly during the first 24 hr postsurgery. Both the thyroglobulin and TBG together with albumin concentration values were decreased after surgery as compared to preoperative values. It is concluded that the changes in thyroid hormone levels after major elective orthopedic surgery seem to be independent of changes in plasma catecholamines and/or cortisol concentrations.