Conversion of supraventricular arrhythmia to normal rhythm by propofol and remifentanil: three cases report
A 52-year-old woman (height 160 cm, weight 47 kg) with a history of hyperthyroidism was scheduled for total radical thyroidectomy because of a gradual increase in the size of the thyroid nodules. The patient's previous medical history was unremarkable. Preoperative laboratory tests, including thyroid function test, and chest x-ray were unremarkable. An electrocardiogram (ECG) taken 1 month prior to surgery showed atrial fibrillation, and transthoracic echocardiography revealed normal left ventricular ejection fraction without regional wall motion abnormalities. She was not given premedication before surgery. In the operating room, non-invasive blood pressure monitoring, ECG (lead II) and a pulse oximetry monitoring were placed. Pre-anesthetic blood pressure was 120/70 mmHg, heart rate was 70 beats/min, and oxygen saturation was 95%. The ECG rhythm was same as preoperative state, suggesting atrial fibrillation is chronic. After preoxygenation, anesthesia was induced with propofol (3.5 µg/ml) and remifentanil (0.1 µg/kg/min) using target controlled infusion (TCI) pump (Orchestra® Base Primea, Fresenius Vial, Brezins, France) and she was intravenously given rocuronium 50 mg. After tracheal intubation, anesthesia was maintained using propofol and remifentanil TCI in an oxygen-air mixture (FiO2 = 0.5). After about 40 minutes, atrial fibrillation converted to the NSR (heart rate, 70 or so), which persisted. On postoperative day 4, the patient was discharged with NSR. One month later, the patient was still having NSR. The patient was lost to follow-up afterwards.