[Perioperative thyroid storm in a patient with undiscovered hyperthyroidism].

Thyroid storm can develop in patients with longstanding untreated hyperthyroidism. It is more often precipitated by an acute event such as surgery, trauma, or infection. We experienced a case in whom thyroid storm occurred during surgery, while he had no preoperative diagnosis of thyroid disease. A 30-year-old man was scheduled for left tympanoplasty. Anesthesia was induced and maintained with sevoflurane and nitrous oxide in oxygen. Heart rate and rectal temperature went up to 140 beats x min(-1) and 39 degrees C, respectively, in 3 hours during surgery. Cooling blanket, cold fluid infusion, flurbiprofen, diltiazem, and verapamil were used to decrease body temperature and heart rate. Surgery was completed and after emergence he was in agitation for 4 hours along with hyperpyrexia and tachycardia. He was diagnosed as hyperthyroidism by postoperative physical and laboratory examination. Thiamazole and propranorol were administered. In one week, symptom has declined with body temperature and heart rate of around 36 degrees C and 90 beats x min(-1), respectively. We should be more careful about evaluation of preoperative patients.