[Acute low triiodothyronine syndrome in the perioperative period]

Serum concentrations of thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) were determined by radioimmunoassay in 11 patients (8 females and 3 males aged 42-65 years) before cholecystectomy and at various time intervals following operation up to 10 days. The surgical procedure was uncomplicated in all the cases studied. The level of rT3 was significantly increased (P less than 0.01) already on the first postoperative day and was then decreasing to its initial value. The levels of T4 and T3 were markedly reduced particularly on postoperative days 2 to 5 (the drop was significant on calculating individual values as percentages of the preoperative level of the given patient). This acutely developing syndrome of low triiodothyronine disappeared spontaneously within 7 to 10 days at a noncomplicated postoperative course.