The clinical and metabolic responses to early surgical treatment for hyperthyroid Graves' disease: a comparison of three pre-operative treatment regimens.

We have compared the clinical and metabolic responses of three groups of patients undergoing subtotal thyroidectomy for hyperthyroid Graves' disease. These patients were prepared for surgery with propranolol alone, propranolol plus potassium iodide or the long acting beta-adrenoceptor antagonist nadolol plus potassium iodide. Pre-treatment with potassium iodide reduced serum T4 to normal or subnormal in all patients. Patients in the propranolol group had significantly higher pulse rates and temperatures after operation and one patient developed an exacerbation of the hypermetabolic state. The perioperative rise in serum cortisol and blood glucose was delayed in patients in the propranolol group and this was also noted in one severely hyperthyroid patient on propranolol + potassium iodide. Nadolol was administered once daily as compared to multiple daily doses with propranolol. Despite this, plasma nadolol levels were consistently higher throughout the perioperative period while propranolol levels in patients on both propranolol alone and propranolol + potassium iodide were highly variable and sometimes undetectable. We conclude that, in the rapid preparation of patients with hyperthyroid Graves' disease for surgery, the combination of nadolol + potassium iodide has significant advantages over the other two regimens.