Congenital long QT syndrome (c-LQTS) is a rare malfunction of cardiac ion channels resulting in impaired ventricular repolarization that can lead to torsades de pointes and sudden death. The management approach depends on the genotype of c-LQTS. Here, we present the safe perioperative management of a patient who underwent two orthognathic surgeries. A 19-year-old woman (144 cm, 47.3 kg) was scheduled to undergo a Le Fort I procedure and a sagittal splitting ramus osteotomy. She had been diagnosed as having c-LQTS genotype 1 (LQTS1) at the age of 6 years based on an observed ECG abnormality and was treated with oral propranolol (60 mg per day). She had no history of syncope or palpitation, but her grandmother had died suddenly and had been diagnosed as having a hereditary factor. The patient’s preoperative ECG showed a sinus rhythm and a long QT (QTc : 461 ms). Propranolol (20 mg) was administered orally at 90 min before the induction of anesthesia. Upon the patient’s arrival in the operating room, standard monitoring devices and direct arterial blood pressure monitoring were applied and defibrillation pads were attached. Her QT interval and serum electrolyte levels were monitored throughout the procedure. Since all halogenated volatile anesthetics are known to prolong the QTc, we selected total intravenous anesthesia (TIVA). General anesthesia was induced and maintained with air oxygen, propofol, remifentanil and rocuronium using a target control infusion pump under BIS monitoring. Her QTc times were within the range of 435-463 ms, and propranolol (2.0 mg) was administrated intraoperatively ; torsades de pointes did not occur during the surgery. After monitoring the patient in the ICU, the tracheal tube was removed the following morning and medication with oral propranolol was started. The efficacy of pharmacological treatment for c-LQTS is known to be genotype specific. Patients with LQTS1 have an increased sensitivity to events provoked by catecholamine ; consequently, they respond well to anti-adrenergic therapy. Although no definitive guidelines outlining the anesthetic management of patients with c-LQTS are available, anesthesiologists should keep in mind that certain anesthetic drugs prolong the QTc, and they should consult with cardiologists regarding the treatment of arrythmias according to the genetic type of LQTS.

  Oral midazolam is an effective method of premedication for pediatric patients and is also sometimes used as a premedication in adult patients with intellectual disability whose cooperation with anesthesia induction can be difficult to obtain. Recently, the effectiveness of intranasal dexmedetomidine (DEX) as a premedication has been reported. However, most studies have been conducted in pediatric patients, and no reports of adult patients have been made. Here, we present a case report in which premedication using intranasal DEX was performed for an adult patient with intellectual disability.

  The patient was a 27-year-old female (weight, 48.5 kg) with intellectual disability, epilepsy, and autism spectrum disorder. Dental treatment under general anesthesia was planned because of a lack of cooperation with dental treatment. She had previously received several dental treatments under general anesthesia during which premedication using oral midazolam had been used. However, it became difficult to obtain her cooperation for premedication using oral midazolam during the repeated treatments requiring general anesthesia. Therefore, premedication using nasal DEX was performed. We provided premedication using nasal DEX on two occasions. On the first occasion, 1.0 μg/kg of DEX was sprayed into the nasal passages using MAD Nasal^TM. However, the sedation level was inadequate (Ramsay Sedation Scale 2), and the patients refused the anesthesia induction. On the second occasion, 1.5 μg/kg of DEX was sprayed into nasal the passages in the same manner as that used previously. This time, an appropriate level of sedation (Ramsay Sedation Scale 3) was obtained and the anesthesia induction was successful.

  The present case report suggests that premedication using intranasal DEX might be a useful method of anesthesia induction for adult patients with intellectual disabilities in whom premedication using oral midazolam is difficult.