Atrial fibrillation (Af) is an abnormal heart rhythm characterized by rapid and irregular beating of the atria. Enhanced activity of the sympathetic nervous system can cause Af perioperatively. The presently reported patient was a 68-year-old man with cervical lymph node metastases from tongue cancer who had undergone radiation therapy. Tachyarrhythmia was observed during the preoperative anesthetic examination, so a cardiology consultation was requested. The patient was subsequently diagnosed as having Af, and antithrombotic therapy was started prior to the operation.
During anesthesia management for the presently reported procedure, we planned to stabilize the hemodynamic status by simulating the effect-site concentration (Ce) of remifentanil. After tracheal intubation, the systolic blood pressure increased to over 180 mmHg, and the Ce of remifentanil was 5.5 ng/ml. Therefore, we planned to maintain the Ce of remifentanil at over 6.0 ng/ml during the neck dissection. After the neck dissection, we reduced the dose of remifentanil while waiting for the result of an intraoperative rapid pathological diagnosis. We then deepened the anesthetic condition after a decision was made to perform an additional resection. Although the Ce of remifentanil was 5.8 ng/ml at the time when the additional resection was started, paroxysmal atrial fibrillation (PAF) occurred. We administered verapamil hydrochloride (5 mg) intravenously, and the cardiac rhythm resumed a sinus rhythm. The pulse rate returned to normal, and the blood pressure decreased. To avoid sympathetic stimulation, we performed tracheal extubation while the Ce of remifentanil was sufficiently high. The Ce of remifentanil is not the only factor affecting the onset of PAF. Preparations for the possible onset of Af should be made as part of preventive management.
