[Case of thyroid crisis with persistent tachycardia diagnosed postoperatively].

A 35-year-old man with multiple bone fractures underwent an emergency operation. On arriving at the operating room, his heart rate was 160 beats x min(-1), and blood pressure was 100/50 mmHg. We anesthetized him with oxygen, sevoflurane, fentanyl and remifentanil. We suspected hypovolemia, and treated him with crystalloid and transfused red cells and fresh frozen plasma so that heart rate and blood pressure could be stabilized. Tachycardia of 140 beats x min(-1) persisted, and landiolol was continuously administered at a rate of 5-10 mg x hr(-1) after a 2.5 mg bolus injection. Heart rate became controlled around 120 beats x min(-1) without hypotension during anesthesia. Finally, we noticed thyroid crisis in this case, and diagnosed it with laboratory data after operation. We should be aware that atypical tachycardia is caused by thyroid crisis.