Alteration in thyroid hormone concentration during and after coronary bypass operation.
The effect of a surgical stress on serum TSH, T4, free T4, T3, rT3 and TBG was measured before, during and after a coronary bypass operation. Precautions were taken to age, sex, pre-operative nutritional state, anamnestic illness, pre- and post-operative medication. Compared to the pre-operative period TSH increased during operation and normalized at the first post-operative day, while only minor alterations for total and free serum T4 were observed. T3 and rT3 declined at the start of extracorporal circulation, T3 remained reduced during the post-operative period, while rT3 reached its pre-operative value at the first post-operative day. It is concluded that the coronary bypass operation evokes a rapid decline in T3, which is not normalized by the TSH induced response of the thyroid gland, while the post-operative period is characterized by a "low T3 state". The clinical relevance of this finding is discussed with respect to the cardiovascular and the nutritional state of the patients in the post-operative period.
D000328:Adult; D001026:Coronary Artery Bypass; D005112:Extracorporeal Circulation; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011863:Radioimmunoassay; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood*; D013975:Thyroxine-Binding Proteins / Q000032:analysis
D013963:Thyroid Hormones; D013975:Thyroxine-Binding Proteins; D013972:Thyrotropin