General anesthesia with remimazolam for tooth extraction in a patient with Noonan syndrome and hypertrophic obstructive cardiomyopathy: A case report

Noonan syndrome (NS) is characterized by various abnormalities and is complicated with cardiac diseases, such as hypertrophic cardiomyopathy, in > 80% of cases. Minimum hemodynamic changes are a crucial factor during general anesthesia in such patients. We report the case of a patient with NS and hypertrophic obstructive cardiomyopathy (HOCM) who underwent general anesthesia using remimazolam, a new ultrashort-acting benzodiazepine anesthetic, which is expected to cause less circulatory depression. A 19-year-old woman with NS complicated with HOCM was scheduled to undergo extraction of the wisdom teeth and second molar under general anesthesia. Preoperative evaluation revealed HOCM with left ventricular outflow tract obstruction and the patient had chronic heart failure. After the placement of an arterial line under moderate sedation with remimazolam, general anesthesia was induced with remimazolam, fentanyl, and rocuronium, followed by anesthesia maintenance with remimazolam and remifentanil. Tracheal intubation was performed using videolaryngoscopy. Local anesthesia and inferior alveolar nerve block were performed using adrenaline-free local anesthetics. Intraoperatively, low-dose phenylephrine was administered continuously to maintain peripheral vascular resistance. At the end of surgery, the endotracheal tube was replaced with an i-gel (R) supraglottic airway device before emergence from general anesthesia. After full recovery from anesthesia, the i-gel (R) was removed, and the patient was transferred to the hospital ward. The perioperative blood pressure and heart rate were maintained within normal ranges, and no cardiovascular events occurred during anesthesia. Anesthesia management using remimazolam and low-dose phenylephrine with reduction in perioperative stress may provide an appropriate circulatory condition for noncardiac surgery in patients with HOCM.