Peri-operative oral triiodothyronine replacement therapy to prevent postoperative low triiodothyronine state following valvular heart surgery

This study evaluated the effect of oral triiodothyronine (T₃) replacement therapy, starting on the day of the surgery, on thyroid hormone concentrations and clinical outcome in high-risk patients undergoing valvular heart surgery. Fifty patients were randomly allocated to either T₃ or placebo. In the treatment (T₃) group patients received 20 μg of oral or nasogastric T₃ every 12 h starting just before induction of anaesthesia and until the first day after surgery. T₃ concentrations were significantly higher in the T₃ group than the placebo group from 1 to 36 h after removal of the aortic cross clamp. The number of patients requiring vasopressin after discontinuing cardiopulmonary bypass was significantly greater in the placebo group than the T₃ group. Significantly fewer patients required vasopressors in the T₃ group on the first day after surgery.