Mitochondrial DNA depletion syndrome (MDS) is an autosomal recessive inherited disorder characterized by a reduction in mitochondrial DNA copy number in clinically affected tissues. We provided anesthetic management to a 14-year-old girl with MDS. She was diagnosed as having MDS based on genetic screening, and she had undergone a liver transplantation at the age of 14 years. She also had mental retardation and seizures. We were unable to provide proper treatment with her cooperation, so dental treatment under general anesthesia was scheduled.

  Since it was important for this patient to maintain her metabolism and, in particular, to avoid hypoglycemia, glucose was administered appropriately to prevent increased catabolism. Anesthesia was induced with sevoflurane, midazolam, remifentanil and rocuronium and was maintained with isoflurane and remifentanil. Her blood glucose level was evaluated every 30 minutes during surgery, and glucose loading was adjusted as needed. Her metabolism remained under control during the anesthesia, and the operation was accomplished uneventfully. Her respiration condition was good after extubation, so she was moved to the pediatric ward.

  Multiple chemical sensitivity is a disease in which autonomic and neuropsychiatric symptoms, such as fatigue, headache, joint pain, insomnia, and dermatitis, occur in response to exposure to a trace amount of a chemical substance. Here, we report the management of intravenous sedation for tooth extraction and caries treatment in a patient with multiple chemical sensitivities.

  A 57-year-old woman visited a nearby dental clinic complaining of dentin hypersensitivity and requiring tooth extraction and treatment for a root fracture in the mandibular right second molar and caries in the mandibular right first premolar. However, she had a history of chemical hypersensitivity and dentophobia. She was referred to our hospital and was scheduled to undergo intravenous sedation in an environment with minimal exposure to inducers.

  We monitored her blood pressure, percutaneous arterial oxygen saturation (SpO₂), and pulse, and a single dose of midazolam (2 mg) and propofol (10 mg) was administered after securing an intravenous route. The continuous administration of propofol was started at 3 mg/kg/h under 3 L/min of oxygen after the patient fell asleep. No symptoms or risks associated with multiple chemical sensitivity were observed during the tooth extraction or caries treatment.

  The patient was successfully treated in an environment that eliminated the triggers for the onset of symptoms of multiple chemical sensitivity after meticulous interviews with specialists in collaboration with each clinical department. Intravenous sedation using midazolam and propofol under 3 L/min oxygen was a successful approach for minimizing the psychosomatic mechanisms of multiple chemical sensitivity in a patient with dentophobia.

  We report a case of delayed loss of consciousness and respiratory depression caused by accidental remifentanil infiltration. A healthy 61-year-old female underwent a tooth extraction and cystectomy for a periapical cyst under general anesthesia. The anesthesia was induced via the intravenous injection of propofol (100 mg), rocuronium (50 mg), and remifentanil (0.2 mcg/kg/min), followed by tracheal intubation, and was maintained via the inhalation of oxygen (2 L/min), air (2 L/min), and sevoflurane (1.5-2%) and the intravenous administration of remifentanil (0.1-0.2 mcg/kg/min). The operative time was 2 h and 29 min, and sevoflurane and remifentanil administration were stopped 5 minutes after the end of the operation. At that time, her forearm and upper arm were swollen. The patient’s tidal volume during spontaneous breathing was 7 mL/kg. About 11 min after tracheal extubation, she showed clear consciousness and sufficient breathing. During transfer from the operation room, she lost consciousness and her SpO₂ fell to below 90%. We immediately returned her to the operating room and performed manual ventilation with a mask. Her blood gases, electrolytes, and glucose values were within the normal ranges. Neuromuscular monitoring showed a TOF count of 4 and a TOF ratio of 92%. She was intubated and transferred to the ICU and was monitored until the following morning. Seventeen hours after surgery, her consciousness and respiration had recovered completely, and the tracheal tube was extubated. Accidental remifentanil infiltration may have caused a delayed loss of consciousness and respiratory depression.

  Smith-Magenis syndrome (SMS) is caused by a heterozygous deletion at chromosome 17p11.2 or a RAI1 pathogenic variant. SMS is characterized by distinctive physical features, developmental delay, behavioral abnormalities, and sleep disturbance. We report our experience providing general anesthetic management to a patient with SMS requiring dental treatment.

  A 6-year-old girl (weight, 21.1 kg ; height, 109 cm) with SMS was scheduled to undergo dental treatment under general anesthesia for 4.5 hours. She had hearing loss, severe sleep disturbance, and behavioral abnormalities. The behavioral abnormalities included self-injury, which occasionally lasted for periods of up to 2 hours. Her pediatrician had prescribed melatonin and aripiprazole. The melatonin was only effective for several hours ; upon awakening, she would attempt to consume whatever food was around her and would become aggressive and self-injurious if food was not available. Since it was deemed difficult for her to adhere to a preoperative fast, we decided to adjust the medication within her existing prescription. We also decided to use propofol for anesthesia maintenance to prevent self-injury arising from emergence excitement.

  Although she awoke twice during the night before receiving anesthesia, she was able to maintain her fast without self-injury. General anesthesia was induced using oxygen and sevoflurane without restraint. We used propofol instead of sevoflurane to maintain the anesthesia. After the procedure, she awoke calmly, and extubation was performed without agitation. No complications were observed during or after the general anesthesia until hospital discharge.

  When providing anesthesia to patients with SMS, it is important to take countermeasures to prevent sleep disturbances and behavioral abnormalities, especially the ability of the patient to adhere to the preoperative fast.

  Many cases of anaphylactic shock and arrhythmias after the administration of sugammadex have been reported. In this report, we describe a case of sinoatrial block or sinus arrest after the administration of sugammadex during ambulatory anesthesia. The patient was a 21-year-old male with autism spectrum disorder. Intensive dental treatment under general anesthesia was planned. The anesthesia was performed using a slow induction with sevoflurane, followed by the use of an intravenous route and nasal intubation after the administration of 50 mg of rocuronium. After the completion of treatment, 200 mg of sugammadex was administered upon awakening, and a sudden bradyarrhythmia appeared immediately after sugammadex administration. The patient’s heart rate decreased to 30 beats per minute and then recovered to 80 beats per minute after the administration of 0.5 mg of atropine sulfate. An electrocardiogram obtained immediately after the administration of sugammadex suggested a sinoatrial block or sinus arrest. Appropriate monitoring using a muscle relaxation monitor is necessary when administering rocuronium bromide and sugammadex. The need for sugammadex administration, the time elapsed since the administration of rocuronium bromide, and the possible occurrence of adverse effects should also be taken into consideration. Sugammadex must be administered appropriately taking its possible adverse effects into consideration. Although the exact mechanism is unknown, severe electrocardiographic changes can occur within a few minutes after sugammadex administration even when sugammadex is used appropriately ; therefore, preparations for the possibility of cardiac arrest should be made if an improvement in cardiac function does not occur.

  The gag reflex not only interferes with dental treatment, but also decreases quality of life in patients who have difficulty brushing their teeth or using dentures. We treated a case in which intravenous sedation with propofol was used in a patient with a severe gag reflex ; as a result of the dentures being made while using the lightest level of sedation that would not permit a gag reflex, the patient was able to wear the dentures for short periods of time.

  The patient was a 64-year-old woman with a pretreatment gagging severity index of grade Ⅴ (most severe) ; psychological factors were strongly involved. Intravenous sedation was performed with conscious sedation, and the sedation level was adjusted while confirming with the patient as to whether treatment was possible. As a result, the Ce (estimated effect-site concentration) of treatable propofol decreased with repeated intravenous sedation. This finding suggested a gradual increase in the threshold at which the gag reflex appeared. Intravenous sedation with propofol may enable efficient desensitization. The repetition of sedation within a short period of time might also have had an additive effect.