Anesthetic management of a dental patient with repeated convulsions and difficult airway management

We treated a special-needs dental patient with epilepsy. Convulsions without changes in the Bispectral Index (BIS®) were observed during the dental treatment, and a severe airway obstruction occurred after extubation. The patient was a 15-year-old boy with well-controlled epilepsy, cerebral palsy, and intellectual disability. On physical examination, he was 17 kg in weight and 109 cm in height. He could not walk by himself, and he had experienced frequent episodes of reduced SpO₂ at meal times, probably because of weak pharyngeal muscles and increased secretion. For the dental treatment, anesthesia was induced with the inhalation of sevoflurane (8%) in nitrous oxide (4 l/min) and oxygen (2 l/min) after the start of SpO₂ monitoring. Once the patient was unconscious, the inhaled anesthetics were changed to isoflurane (1%) in oxygen (6 l/min), and blood pressure monitoring, electrocardiography, and BIS monitoring were started. We administered rocuronium (10 mg), atropine (0.1 mg) and fentanyl (30 μg) after confirming easy mask ventilation. The patient was intubated with a 5.5-mm nasotracheal tube by direct laryngoscopy. A convulsion lasting five seconds occurred when the patient's throat was packed with gauze. In addition, convulsions occurred several times during the dental treatment when the teeth were shaved. Remifentanil, but not propofol, was useful for preventing the convulsions. The cause of the convulsions might have been small stimulations, such as vibrations, which were difficult to control using local anesthesia. After extubation, an upper airway obstruction occurred, probably because of the patient's weakened peripharyngeal muscles, delayed awakening from anesthesia, and increased secretion. Therefore, the patient was re-intubated until the following day. The history of complications and present condition of patients should be considered when managing unexpected troubles during the perioperative period.