Successful treatment of thyrotoxic crisis with plasma exchange.

A 36-yr-old woman with thyroid storm was successfully treated with plasma exchange. After the first plasma exchange, free serum thyroxine (T4) was decreased and serum thyroxine-binding globulin (TBG) was significantly increased. The decrease in the patient's free T4 level after plasma exchange can perhaps be attributed to T4's increased binding capacity. Plasma exchange may be an effective therapy for thyrotoxic crisis and should be performed immediately if conventional therapy fails to improve the patient's condition.