A 27-year-old woman with a history of atopic dermatitis and allergic rhinitis underwent a Le Fort I osteotomy and bilateral mandibular sagittal bifurcation.

  During the insertion of a 6.5-mm I. D. tracheal tube into the left nasal vestibule, the tube hit the posterior pharyngeal wall but was placed stably. During the surgery, the patient’s vital signs were stable. The total amount of blood loss was 100 ml, and the Hb value was 11.0 g/dl. However, because of unexpected epistaxis after extubation that could not be managed by the insertion of surgical pads into the nasal cavity, reintubation was required. Since the airway was blocked by the surgical pads and a suction catheter, there was not enough time to apply mask ventilation. Therefore, midazolam and remifentanil hydrochloride were infused, instead of the inhalation anesthetics and muscle relaxants, and reintubation was performed orally while continuing suction. Thereafter, the administration of dexmedetomidine hydrochloride was initiated. After the otolaryngologist filled the patient’s nasal cavity with surgical pads and lifted the patient’s head upwards, the bleeding eventually stopped. Nasal mucosa cautery was performed near the left sphenopalatine foramen. An analgesic was also added, and the patient was safely managed under spontaneous breathing and extubated. The total blood loss was 1,215 ml, and the Hb value was 8.4 g/dl.

  Damage to the mucosa near the sphenopalatine foramen can cause unexpected bleeding. The immediate decision to administer appropriate drugs led to a prompt intubation and minimized the bleeding. The administration of dexmedetomidine hydrochloride helped to suppress circulatory changes, reduce the anesthetics, and prevent emergence agitation during the nasal mucosa cautery procedure.

  Accidents during dental anesthesia can have a direct impact on the lives of patients. Therefore, measures to prevent incidents are crucial. However, no studies to date have looked at incident reports made during dental anesthesia practice. Here, we examined 123 incident reports related to dental anesthesia made at Osaka University Dental Hospital between May 2007 and March 2019. The majority of the incidents were related to drug administration, endotracheal tube problems, and the intraoral retention of gauze packing following oral surgery. Several errors in the unit settings used for the rate of drug administration with syringe pumps were reported. In addition, instances of accidental ingestion were observed during dental treatment under intravenous sedation. The majority of the incidents were caused by human error, such as not confirming the accuracy of the treatment conditions, carelessness, or a lack of observation. In dental anesthesia practice, both the surgical field and the patient’s airway are located in the same intraoral region. Therefore, clinicians should focus on incidents associated with airway problems, such as damage to the tracheal tube, the retention of intraoral gauze packs, and the cough reflex under intravenous sedation. Incident reports should also be used to guide clinical practice so that the frequencies of incidents are reduced in the future.

  A bronchial fiberscope (BFS) is an endotracheal intubation device for obtaining a clear view of various intubation devices in difficult intubation situations. However, intubation can still be difficult even if a BFS is used, and various additional intubation aids may be required. We report a patient with cervical kyphosis in whom the insertion of a BFS into the trachea was difficult despite a clear view of the glottis.

  A 24-year-old man with autism, mental retardation, and severe head anteflexion resulting from cervical kyphosis was scheduled to undergo dental treatment under general anesthesia. During tracheal intubation, the patient’s glottis could not be visualized using either a GrideScope^® or a McGRATH^TM because of a narrow oral cavity caused by trismus and impaired anterior sliding of the mandibles. We used a BFS and obtained a clear view of the glottis but were unable to advance the tip of the BFS to the glottis because of the large distance between the glottis and the BFS tip. We then used a Deschamps needle inserted into the oral cavity to change the direction of the intubation tube and succeeded in achieving tracheal intubation. Deschamps needles are instruments that were originally used in ophthalmic surgery. We believe that Deschamps needles could be useful instruments during intubation, especially in cases with narrow oral cavities.

  We performed intravenous sedation for the extraction of deciduous teeth in a 9-year-old boy with hypoplastic left heart syndrome (HLHS) and intellectual disability who had previously undergone a Glenn procedure. He had previously been diagnosed as having HLHS and had undergone pulmonary artery banding, a Norwood procedure and a Glenn procedure. However, he had not yet undergone a Fontan operation because of the poor growth of the pulmonary vascular bed. After the Glenn procedure, a shunt that allowed the mixing of venous blood from the inferior vena cava and arterial blood from the pulmonary vein was left in place, and pulse oximetry showed an Spo₂ of 85% oxygen saturation with the provision of 1 l/min of oxygen in everyday life. Furthermore, he had severe intellectual disability and could hardly communicate. He had experienced episodes of cyanosis because of agitation and crying during rehabilitation. To prevent cyanosis as a result of agitation and crying, we decided to extract the deciduous teeth under anesthesia management. Intravenous sedation was selected because of the minimally invasive and short-term surgery. Intravenous sedation was induced and maintained using ketamine to avoid circulatory and respiratory suppression. Cyanosis did not occur, and no significant changes in the patient’s vital signs were observed throughout the period of intravenous sedation. Although ketamine increases airway secretion, no problems with airway management occurred in the present case. Intravenous sedation with ketamine is likely to be a safe and effective management for patients who have undergone a Glenn procedure.

  Several reports in the dental field have discussed post-hyperventilation apnea (PHA) during sedation. Here, we report the case of a 44-year-old woman with PHA who received dental treatment without experiencing apnea while under intravenous sedation with dexmedetomidine and hydroxyzine.

  The patient had no history of hyperventilation and had never taken anxiolytics in her daily life. Initially, we used midazolam to sedate her. During treatment, the patient developed tachypnea, followed by tetany. After an additional 3 mg of midazolam, the patient developed apnea. We then initiated artificial ventilation using a bag-valve mask. Propofol was used during a second and third sedation, but she developed tachypnea during treatment and apnea after treatment. For a fourth sedation, we used hydroxyzine and dexmedetomidine. Hyperventilation and apnea did not occur during or after the treatment, and she could not recall any sensations during the treatment.

  Hyperventilation reduces the partial pressure of arterial carbon dioxide, thereby decreasing respiratory stimulation from central chemoreceptors. As a result, PHA can develop because of the decrease in the ventilatory response. Drugs such as benzodiazepines and propofol may promote the development of PHA by inhibiting central chemoreceptor function and the behavioral respiratory control system. Dexmedetomidine can prevent hyperventilation attacks by its sympathetic depressant effect. When treating patients with hyperventilation syndrome, the possibility of apnea should be considered and the patients’ respiratory status should be monitored. To prevent the development of PHA, it is important to select drugs that minimize respiratory depression yet have a sufficient sedative ability, such as dexmedetomidine and hydroxyzine.