Effects of General Anesthesia Using Remifentanil on Hemodynamics during Oral Surgery

used to achieve analgesia during general anesthesia. Due to excellent ad-justability, remifentanil, a strong opioid analgesic, is widely used during general anesthesia while performing oral surgery. However, caution is advised since remifentanil lowers blood pressure and heart rate. This study examined the effect of remifentanil on circulatory fluctuations while performing oral surgery under general anesthesia. The subjects were cases of general anesthesia performed in the hospital affiliated with our university between 2014 and 2017. Information was obtained from medical records and anesthesia minutes, regarding patient characteristics, surgical procedure, remifentanil use, drugs used to induce and maintain anesthesia, circulatory fluctuations during surgery, and management of hemodynamic events. Among the 1,474 cases in this study, remifentanil was used in 795 cases during general anesthesia（R group）. Within R group, circulatory fluctuations appeared in 46 cases, the most common being bradycardia（22 cases）and hypotension（11 cases）. A treatment for circulatory fluctuations（bradycardia ［2.8%］ and hypotension ［1.5%］）was administered in 54 cases（6.8%）. Hypotension was often seen in the elderly and in patients who had taken hypotensive medicine prior to the surgery. Bradycardia often occurred during corrective surgery, open reduction, and internal fixation. Circulatory inhibition under general anesthesia occurs easily with remifentanil use, which has a parasympathetic nerve stimulation effect, during maxillofacial surgery and cervical procedures where vagal reflexes such as trigeminal nerve stimulation and carotid sinus compression are likely to occur.