Co-administration of Magnesium Oxide Reduces the Serum Concentration of Hydrophobic Basic Drugs in Patients Treated with Antipsychotic Drugs.

Magnesium oxide (MgO) is a widely used laxative. Because many antipsychotic drugs are lipophilic-basic-compounds, their solubility decreases with increasing pH and changes markedly as the pH of the solution approaches their pKa. It is highly important to clarify the effect of co-administration of MgO on the serum drug concentration for effective, safe, and appropriate medication therapy. However, the relationship between MgO administration and the serum concentration of antipsychotic drugs in patients with schizophrenia has not been reported. Therefore, in the present study, we investigated the effect of MgO administration on the concentration of antipsychotic drugs in the blood of patients with schizophrenia. The serum concentrations of biperiden, zotepine, and risperidone were assayed using an LC/MS system. The correlation between the daily dose of MgO and the relative-drug-concentration (rCp) in each patient was examined. As the MgO dose was increased, the risperidone concentration decreased. The correlation coefficient decreased for risperidone, zotepine, and biperiden, in the same order. To clarify the difference in the suppression potency of MgO on the three drugs, the relationship between the physical properties and the correlation coefficients of each drug was carefully examined. A strong correlation was observed between the pKa and the correlation coefficient. Patients with schizophrenia are often prescribed antipsychotic drugs, which have anticholinergic action and tend to suppress gastric acid secretion. We concluded that basic drug absorption might be suppressed due to an increase in the stomach pH following MgO administration. Therefore, MgO co-administration is better to avoid while taking antipsychotic drugs and anticholinergic drugs.

[A case of endotracheal intubation in prone position utilizing PENTAX-Airwayscope for morbidly obese patient].

We experienced the airway management of a morbidly obese patient in prone position utilizing PENTAX-Airwayscope (AWS) which is a novel airway device for endotracheal intubation. A 29-year-old man, who was 150 kg in weight and 51.9 kg x m(-2) in body mass index, was scheduled for the discectomy for lumbar disc herniation. After the topical anesthesia with lidocaine spray, the patient lay on his stomach by himself on the table. Following the induction of general anesthesia with ketamine and dexmedetomidine in prone position, an anatomically curved blade (INTLOCK) was inserted to his oral cavity first, then the body of AWS was attached. With the patient breathing spontaneously, we successfully inserted the reinforced endotracheal tube. After the maintenance of anesthesia with continuous infusion of dexmedetomidine, ketamin and remifentanil, the patient awoke clearly without pain and endotracheal tube was removed safely in the prone position. Although the prone position is not the standard position for endotracheal intubation under general anesthesia, our technique could be performed in emergency situations.

[Anesthetic management using esmolol for arthroscopic synovectomy in a patient with thyroid storm].

We report a case of a 47-year-old woman with past medical history of Graves disease who presented with thyroid storm, a state of physiologic decompensation due to severe thyrotoxicosis, and arthritis purulenta. Antithyroid therapy ameliorated thyrotoxicosis in 4 days, and arthroscopic synovectomy of the right knee was performed. Anesthesia was induced with intravenous propofol. Esmolol, an ultra-short-acting beta blocker listed in national drug tariff of Japan for intraoperative continuous iv infusion in March 2008, was also administered to control heart rate. Then, laryngeal mask airway was inserted and echo-guided femoral nerve block was done with ropivacaine. Anesthesia was maintained with i.v. infusion of propofol and fentanyl. Short episode of supraventricular tachycardia occurred twice, but each tachycardia disappered in about a half minute. The postoperative course was uneventful. Esmolol probably acted to prevent intraoperative tachycardia due to increased beta-adrenergic tone.

[Comparison of BIS and Ramsay score for evaluation of sedation with propofol in ICU].

BACKGROUND: BIS has not been evaluated for sedation in ICU. We examined BIS for evaluation of sedation with propofol in ICU. METHODS: Eighteen male patients undergoing head and neck surgery (ASA-PS 1 x 2 and age<75 years) were randomly allocated to one of two groups receiving postoperative sedation with propofol in ICU. One group was monitored for sedation by BIS, and the other group by Ramsay score. RESULTS: There were no significant differences between the two groups in the total-dose of propofol, and recovery time. CONCLUSIONS: The use of BIS for sedation could not improve the management of postoperative sedation in ICU.

[Perioperative management of a patient with subarachnoid hemorrhage complicated with descending aortic dissection].

A 62-year-old man with descending aortic dissection received general anesthesia for clipping of aneurysm of the cerebral artery. We chose a surgical operation for the aneurysm of the cerebral artery, and conservative therapy for the dissection of the aorta. We gave balanced anesthesia with blood pressure control using calcium channel blocker. Anesthesia was induced with propofol, fentanyl, and vecuronium, and maintained with isoflurane, fentanyl, nitrous oxide and oxygen. Transesophageal echocardiography was useful for checking dissection of the aorta. Perioperative course was uneventful.

[Anesthetic management of a patient with deficiency of congenital coagulation factor XII].

A 63-year-old man with deficiency of congenital coagulation factor XII, was referred to our hospital for an operation of the hypopharynx cancer. The day before surgery under general anesthesia, fresh frozen plasma was administered to him with good response of APTT shortening from 397.0 to 36.4 seconds. During operation, bleeding tendency was controlled and fresh frozen plasma was administered. Total blood loss during the operation was 255 ml. During post-operative period, APTT was kept at an adequate level. The post-operative course was uneventful and he was discharged after the radiation and an adjuvant therapy.