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The depression of evoked fast excitatory postsynaptic potentials (EPSPs) following superfusion with various concentrations (3 µM-5 mM) of ammonium chloride (NH4Cl) were investigated in rat hippocampal CA1 neurons. The amplitude of the evoked fast EPSPs decreased by NH4Cl in a concentration-dependent manner. The half-maximal inhibitory concentration for the inhibition of evoked fast EPSPs was 198 ± 125 µM (n = 8). The facilitation of a pair of field EPSPs elicited by paired-pulse stimulation (40-ms interval) (paired-pulse facilitation, PPF) was recorded following superfusion with NH4Cl (200 µM and 3 mM). The PPF ratio increased to 180 ± 23% (n = 9) in the presence of 200 µM NH4Cl compared with that in the absence of NH4Cl (142 ± 24%, n = 9). In the presence of 3 mM NH4Cl, the PPF ratio increased to 172 ± 30% (n = 7) compared with that in the absence of NH4Cl (126 ± 13%, n = 7). This implies that NH4Cl suppressed the presynaptic release of glutamate. Exogenous glutamate- or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-induced depolarization elicited by using pressure application did not reduce following superfusion with 200 µM or 5 mM NH4Cl in the presence of 0.3 µM tetrodotoxin, suggesting that NH4Cl did not affect the postsynaptic glutamate response. Action potentials elicited by rectangular outward current injection from CA3 neurons projecting to CA1 neurons were persistent at 200 µM NH4Cl but disappeared at 5 mM NH4Cl. The abolishment of action potentials in the presence of 5 mM NH4Cl was released by increasing the amplitude of the injection current. These results suggest that NH4Cl depresses evoked fast EPSPs mainly via a presynaptic mechanism at low NH4Cl concentrations, and the failure of action potential propagation through the excitatory nerve may also contribute to the depression of evoked fast EPSPs at high NH4Cl concentrations.

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An intraperitoneal giant tumor can form deep venous thrombosis (DVT), leading to pulmonary embolism (PE) when it is removed. We report a case of a giant ovarian cystic tumor with possible DVT. A 52-year-old woman (149 cm in height, 85 kg in weight, and 150 cm in ventral girth) underwent the laparoscopic resection of the cyst. Preoperative angiography showed the obstruction of the inferior vena cava (IVC) just below the level of the right renal vein due to the compression by the tumor, and computed tomography suggested the existence of distal DVT. Anesthesia was induced with propofol and fentanyl, and the trachea was intubated using rocuronium. A permanent type IVC filter was placed near the obstruction site to prevent PE. Transesophageal echocardiography (TEE) was employed to detect the thrombotic echogram at the right atrium. Anesthesia was maintained with inhalation of sevoflurane and intravenous infusion of remifentanil. The content of the cyst (40.5 l) was suctioned slowly in about 50 min to avoid reexpansion pulmonary edema and circulatory collapse. Neither thrombotic echogram nor the acute decrease in end-tidal carbon dioxide pressure was observed throughout the anesthesia. Operation was performed uneventfully, and she recovered from anesthesia. We consider that IVC filters and TEE are useful to manage surgical patients with a huge ovarian cyst.

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Rett syndrome (RTT) is a congenital neurological disorder associated with mutations in the gene encoding MECP2 on the X chromosome. An 18-year-old woman (150 cm in height and 29 kg in weight) had been diagnosed with RTT and showed myotonic trismus, frequent attacks of apnea, mental retardation, spastic paraplegia, scoliosis, and microcephalus with micrognathia. She was scheduled to undergo laparoscopic fundoplication and gastrostomy under general anesthesia. Nasal bronchofiberscopic intubation (BFI) was planned because difficult airway due to trismus and micrognathia was expected. Referring to the bispectral index (BIS), anesthesia was induced with intermittent intravenous thiopental (total 125 mg), resulting in successful opening of the mouth by 1.5 of a finger width and establishment of manual ventilation. Following intravenous administration of rocuronium (20 mg), oral BFI was easily accomplished despite Cormack grade III. Anesthesia was satisfactorily maintained with inhalation of sevoflurane (1.0-1.5%) and continuous infusion of remifentanil (0.1-0.2 microg x kg(-1) x min(-1)) with the BIS value ranging from 30 to 50. She recovered smoothly from anesthesia using sugammadex (50 mg). However, she immediately demonstrated trismus and an attack of apnea with shivering, which were successfully resolved by warming the body and intravenous fentanyl (50 microg bolus and subsequent infusion at a rate of 10 microg x hr(-1)). The postoperative course was uneventful. Characteristically, RTT shows an extremely wide range of neurological symptoms. Therefore, it is of great importance to respond to each of those symptoms during the perioperative management of patients with RTT.

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Endocannabinoid anandamide, arachidonylethanolamine (AEA), is considered to be a causative mediator of hemorrhagic or septic shock, inducing death of several types of cells by producing free radicals such as reactive oxygen species (ROS). Propofol contains a phenolic hydroxyl group that donates electrons to the free radicals, and thus functions as an antioxidant. The purpose of this study was to investigate the protective effect of propofol against AEA-induced cell injury. After incubation with propofol at concentrations of 10, 50 or 100 µM, human umbilical vein endothelial cells (HUVECs) were stimulated with 10 µM of AEA for 24 h. ROS production, caspase-3 activity, and cell viability were evaluated 1, 8, and 24 h after the administration of 10 µM of AEA, respectively. Propofol (50 µM) significantly attenuated cell death induced by AEA, showing a protective effect against ROS production and caspase-3 activity. These results suggest that propofol at concentrations used during clinical anesthesia protects HUVECs against AEA-induced injury, in part by suppressing apoptosis.

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We report two cases for anesthetic management of gastrectomy for gastric cancer which took place after receiving coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). The first patient was a 75-year-old man after CABG using the RGEA 14 years before. He was diagnosed with gastric cancer and was scheduled for total gastrectomy. Preoperative coronary angiography (CAG) showed complete occlusion of the right coronary artery (RCA), whereas RGEA was patent. Because percutaneous coronary intervention (PCI) was hard to perform on the occluded RCA, proximal gastrectomy was carried out without lymph node dissection. The surgeons judged the surgery enough for radical treatment. Surgery was accomplished without any problems. The second patient was a 76-year-old man after CABG using the RGEA 15 years before. He was diagnosed with advanced gastric cancer and was scheduled for distal gastrectomy. Preoperative CAG showed the RCA partially occluded and the RGEA remaining patent. He received the scheduled surgery after confirmation of the success of PCI, performed preoperatively for reperfusion of the occluded segments. Although the RGEA was incised during the surgery, gastrectomy was accomplished without any problems in the cardiac function.

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