歯科処置中にモニター管理を行った高齢患者の併存疾患と循環器系合併症に関する検討

歯科処置中にモニター管理を行った高齢患者の併存疾患と循環器系合併症に関する検討


歯科口腔外科手術における高齢患者の麻酔方法と術前合併疾患に関する検討

歯科口腔外科手術における高齢患者の麻酔方法と術前合併疾患に関する検討


Total Intravenous Anesthesia Using Remimazolam and Continuous Cardiac Output Monitoring for Dental Anesthesia in a Patient With Takayasus Arteritis: A Case Report

Takayasu's arteritis is a persistent chronic progressive inflammation of the large- and medium-caliber arteries. Controlling cardiovascular variability during anesthesia and overcoming difficulties of cardiovascular monitoring due to the impaired vessels are important in patients with Takayasu's arteritis. Remimazolam is a novel short-acting benzodiazepine with mild effects on hemodynamics. We report the case of a patient with Takayasu's arteritis who underwent oral surgery under general anesthesia. This report highlights the use of remimazolam and remifentanil to reduce hemodynamic perturbations using estimated continuous cardiac output monitoring.


Management of a patient with tracheal stenosis after previous tracheotomy

Tracheal stenosis after tracheotomy can cause difficult airway management and respiratory complications. It is difficult to predict tracheal stenosis after tracheotomy based on a patient's symptoms as the symptoms of tracheal stenosis appear only after they become severe. In patients with a history of previous tracheotomy, it is important to consider the risk factors for tracheal stenosis. Detailed preoperative evaluation of patients with a history of previous tracheotomy is essential and should include 3-dimensional assessment of the airway. We report the preoperative assessment and perioperative management of an 83-year-old woman at high risk for tracheal stenosis due to a previous emergency tracheotomy who was scheduled to undergo general anesthesia for a right maxillectomy for squamous cell carcinoma. Preoperative anteroposterior chest radiograph revealed findings indicative of tracheal stenosis. Additional detailed examinations of the stenotic area were conducted with computed tomography imaging and bronchofiberscopy. General anesthesia with nasotracheal intubation was performed, and although there were no adverse intraoperative events, stridor after extubation was observed. Nebulized epinephrine was administered via an ultrasound nebulizer and effectively improved the patient's postoperative transient dyspnea.


A Retrospective Case Series of Anesthetic Patients With Epiglottic Cysts

Previously undiagnosed or asymptomatic epiglottic cysts may be coincidentally detected during intubation. This retrospective case series identified undiagnosed epiglottic cysts that were discovered during intubation in 4 patients who underwent oral surgery under general anesthesia at our hospital during a 6-year period. Including 2 additional cases, 1 previously diagnosed and 1 detected during preoperative imaging, epiglottic cysts were observed in 6 of 1112 cases (0.54%) total. Among the undiagnosed epiglottic cyst cases, mild dyspnea on effort or snoring was reported in 2 patients, but all others were asymptomatic. Upon discovering previously undiagnosed epiglottic cysts during intubation, it is essential to proceed cautiously, remain alert for potential airway management difficulties, and avoid injuring or rupturing the cysts. In addition, any available preoperative imaging should be reviewed as information pertinent to the airway and any abnormalities may be useful. This report discusses the anesthetic care of 6 patients with epiglottic cysts that were previously known or initially discovered during intubation.


Viability of intensive insulin therapy during pediatric surgery


Clinically relevant concentration of propofol and benzodiazepines did not affect in vitro angiogenesis.

Angiogenesis, one of regenerative medicine, is essential in the process of wound healing. The detailed effects of intravenous anesthetics and sedatives used during perioperative period have not yet been clarified. We investigated the effects of benzodiazepines and propofol on in vitro capillary tube formation. The effects of midazolam, diazepam and propofol (1, 10, 50 M each) on proliferation of human umbilical vein endothelial cells (HUVEC) and normal human diploid fibroblasts (NHDF) were determined. Quantitation of migration was achieved by measuring the fluorescence of migrating HUVEC using angiogenesis system. The effects of midazolam, diazepam and propofol on in vitro angiogenesis were investigated in co-cultured HUVEC and NHDF incubated. The effects of midazolam on activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases were examined by Western blot analysis using phospho-specific antibodies. Parametric data were analyzed with one-way repeated measures analysis of variance followed by the Scheff test. A value of P < 0.05 was considered statistically significant. Fifty M of midazolam significantly impaired endothelial cell proliferation, migration, and in vitro capillary tube formation. Propofol, diazepam or lower dose midazolam did not show any enhancing or suppressive effects on in vitro angiogenesis. Fifty M of midazolam remarkably activated ERK, but not p38 MAPK in HUVEC. Propofol and benzodiazepines except high-dose midazolam did not affect in vitro angiogenesis. High-dose midazolam may impair in vitro capillary tube formation due to by suppressing proliferation and migration of endothelial cells via activation of ERK.


細胞骨格ターンオーバー調節物質による細胞内経路制御機構の解明と麻酔薬作用

細胞骨格ターンオーバー調節物質による細胞内経路制御機構の解明と麻酔薬作用


Cytoskeleton-disrupting agent cytochalasin B reduces oxidative stress caused by high glucose in the human arterial smooth muscle

The role of cytoskeleton dynamics in the oxidative stress toward human vasculature has been unclear. The current study examined whether the cytoskeleton-disrupting agent cytochalasin B reduces oxidative stress caused by high glucose in the human arterial smooth muscle. All experiments in the human omental arteries without endothelium or the cultured human coronary artery smooth muscle cells were performed in d-glucose (5.5 mmol/L). The exposure toward d-glucose (20 mmol/L) for 60 min reduced the relaxation or hyperpolarization to an ATP sensitive K channel (KATP) opener levcromakalim (10 to 3 × 10 mol/L and 3 × 10 mol/L, respectively). Cytochalasin B and a superoxide inhibitor Tiron, restored them similarly. Cytochalasin B reduced the NADPH oxidase activity, leading to a decrease in superoxide levels of the arteries treated with high d-glucose. Also, cytochalasin B impaired the F-actin constitution and the membrane translocation of an NADPH oxidase subunit p47phox in artery smooth muscle cells treated with high d-glucose. A clinical concentration of cytochalasin B prevented human vascular smooth muscle malfunction via the oxidative stress caused by high glucose. Regulation of the cytoskeleton may be essential to keep the normal vascular function in patients with hyperglycemia.


GaN Schottky Barrier Diode-Based Wideband and Medium-Power Microwave Rectifier for Wireless Power Transmission


Pathophysiology and complications during extracorporeal circulation

The Journal of Medical Investigation : JMI


Electrons released from both flavins of NADPH-P450 reductase contribute to the reductive mobilization of iron from ferritin.

Ferritin, an iron storage protein, plays an important role in iron homeostasis. The mechanism of reductive mobilization of iron from ferritin has not been clarified yet despite many studies. The aim of this study was to assess the mechanisms of the mobilization of iron from ferritin by NADPH P-450 reductase. Nucleotide-dependent flavoenzymes generated significant mobilization of iron from ferritin. The possibility of reductive mobilization of iron from ferritin by electrons released from flavin sites or heme site of two flavoenzymes was investigated to elucidate the mediator-independent mechanisms of such reductive mobilization. The mobilization by NADPH-P450 reductase in the presence of ferricyanide increased threefold, while in the presence of cytochrome C increased thirteen-fold. These results indicate that electrons released from both flavins of NADPH-P450 reductase contribute to the reductive mobilization of iron from ferritin. The mechanism of the mobilization of iron from ferritin is discussed. J. Med. Invest. 66 : 230-232, August, 2019.


Continuous blood glucose monitoring during pediatric cardiopulmonary bypass.


Accuracy and reliability of continuous blood glucose monitoring during pediatric cardiopulmonary bypass.

The purpose of this study was to assess the accuracy and reliability of a continuous blood glucose monitoring system (artificial endocrine pancreas; STG-55, Nikkiso, Tokyo, Japan) during pediatric cardiopulmonary bypass surgery. Twenty-five pediatric patients scheduled to undergo cardiovascular surgery with cardiopulmonary bypass (age 4 months to 11 years; body weight 5.6-59.7 kg) were enrolled. The glucose sensor line of the artificial endocrine pancreas was connected to the venous side of the cardiopulmonary bypass circuit and used for continuous blood glucose monitoring. We obtained 192 samples for blood gas assessment from the cardiopulmonary bypass circuit, and i-STAT (Abbott, East Windsor, NJ, USA) was used for conventional blood glucose assessment. The accuracies of continuous glucose measurements (STG-55) and conventional intermittent glucose measurements (i-STAT) during cardiopulmonary bypass were compared by means of Clarke error grid analysis. The results were divided into five zones, A, B, C, D, and E, and 78.6% of paired measurements were in zone A, while 21.4% were in zone B. We confirmed that the results of this continuous blood glucose monitoring system for cardiopulmonary bypass during pediatric cardiovascular surgery were highly reliable. An artificial endocrine pancreas may facilitate the safe use of intensive insulin therapy during pediatric cardiovascular surgery.


GaN Schottky barrier diodes with nickel nitride anodes sputtered at different nitrogen partial pressure


Ultrasound-guided Peripheral Nerve Block and General Anesthesia for Hepatectomy in a Patient with Chronic Inflammatory Demyelinating Polyneuropathy

慢性炎症性脱髄性多発根ニューロパチー患者に対する肝切除術の麻酔経験


Peripartum Cardiomyopathy after Cesarean Section in a Patient with Myotonic Dystrophy

帝王切開後に産褥性心筋症を発症し心不全に陥った筋緊張性ジストロフィー妊婦の麻酔経験


Intraoperative Change in QTc in a Patient with a Prolonged QTc Interval

QTc延長患者における全身麻酔中のQTc変動

 Long QT syndrome is characterized by a prolongation of the QT interval and a morphological change in the T wave on an electrocardiogram. Prolongation of the QT interval is associated with serious arrhythmia and may cause syncope and sudden death. A 13-year-old male with a prolonged corrected QT interval (QTc) on a preoperative electrocardiogram was scheduled to undergo the extractation of a supernumerary tooth under general anesthesia.

 Although he had no remarkable past medical history, his QTc was prolonged to 514 ms on a 12-lead electrocardiogram. There was no history of syncope or sudden death in his family. The QTc at the time of his entrance into the operation room was 483 ms. During surgery, his QTc was continuously monitored in addition to the usual intraoperative monitoring. After the rapid introduction of anesthesia with remifentanil and propofol, the anesthesia was maintained with remifentanil and sevoflurane in oxygen and air. No significant change in the QTc was observed at the time of tracheal intubation accompanied by sympathetic stimulation. There was also no significant change in the QTc after the administration of atropine for bradycardia. However, when 2% lidocaine containing adrenaline was used for local anesthesia, the QTc gradually became prolonged reaching a maximum of 507 ms. In patients with a prolonged QT interval on a preoperative electrocardiogram, careful attention may be needed during the use of local anesthetics containing adrenaline. In addition, continuous monitoring of the QTc during surgery may be useful for the prevention of serious arrhythmias.

Journal of Japanese Dental Society of Anesthesiology


Nasotracheal intubation through pharyngeal flap after pharyngeal flap construction.


閉塞型睡眠時無呼吸症候群を伴った成人スティル病患者の嚢胞摘出術における静脈内鎮静法下患者管理の経験


Stevens-Johnson症候群の既往がある難治性てんかん患者の全身麻酔経験


Successful treatment of mixed (mainly cancer) pain by tramadol preparations

The patient, a 70-year-old Japanese woman diagnosed with parotid gland cancer, underwent wide excision and reconstruction (facial nerve ablation, nerve transposition). At 1 month after the surgery, she was brought to our hospital's pain medicine department because her postoperative pain and cancer-related pain were poorly controlled. She had already been prescribed a tramadol (37.5 mg)/acetaminophen (325 mg) combination tablet (5 tablets/day). However, in addition to the continuous pain in her face and lower limbs, she was troubled by a trigeminal neuralgia-like prominence ache. Because this pain could not be controlled by an increase to eight combination tablets per day, we switched her medication to a tramadol capsule. At 11 months post-surgery, we then switched her medication to an orally disintegrating tramadol tablet to improve medication adherence of the drug. From 14 months post-surgery, the patient also used a sustained-release tramadol preparation, and she was then able to sleep well. Her current regimen is an orally disintegrating sustained-release tablet combination (total 300 mg tramadol) per day, and she achieved sufficient pain relief. Because tramadol is not classified as a medical narcotic drug, it widely available and was shown here to be extremely useful for the treatment of our patient's mixed (mainly cancer) pain. J. Med. Invest. 64: 311-312, August, 2017.

The Journal of Medical Investigation : JMI


Strict blood glucose control by an artificial endocrine pancreas during hepatectomy may prevent postoperative acute kidney injury

The aim of the present study was to evaluate the usefulness of a closed-loop system (STG-55; Nikkiso, Tokyo, Japan), a type of artificial endocrine pancreas for the continuous monitoring and control of intraoperative blood glucose, for preventing postoperative acute kidney injury (AKI) in patients undergoing hepatectomy. Thirty-eight patients were enrolled in this study. Glucose concentrations were controlled with either a manual injection of insulin based on a commonly used sliding scale (manual insulin group, n = 19) or the programmed infusion of insulin determined by the control algorithm of the artificial endocrine pancreas (programmed insulin group, n = 19). After the induction of anesthesia, a 20-G intravenous catheter was inserted into the peripheral forearm vein of patients in the programmed insulin group and connected to an artificial endocrine pancreas (STG-55). The target range for glucose concentrations was set to 100-150 mg/dL. The mean serum creatinine concentrations of preoperative, postoperative 24 and 48 h were 0.72, 0.78, and 0.79 mg/dL in the programmed insulin group, and 0.81, 0.95, and 1.03 mg/dL in the manual insulin group, respectively. Elevations in serum creatinine concentrations postoperative 48 h were significantly suppressed in the programmed insulin group. The STG-55 closed-loop system was effective for maintaining strict blood glucose control during hepatectomy with minimal variability in blood glucose concentrations and for suppressing elevations in serum creatinine concentrations. Strict blood glucose control by an artificial endocrine pancreas during hepatectomy may prevent postoperative AKI.


Contractile response of lipopolysaccharide-treated rat thoracic aortas ot adrenaline or noradrenaline with or without local anaesthetic agents.


Anesthetic management of a patient with unruptured sinus of valsalva aneurysm with right ventricular outflow tract obstruction.


C-terminal region of GADD34 regulates eIF2alpha dephosphorylation and cell proliferation in CHO-K1 cells.

GADD34 is a member of a growth arrest and DNA damage (GADD)-inducible gene family. Here, we established a novel Chinese hamster ovary (CHO)-K1-derived cell line, CHO-K1-G34M, which carries a nonsense mutation (termed the Q525X mutation) in the GADD34 gene. The Q525X mutant protein lacks the C-terminal 66 amino acids required for GADD34 to bind to and activate protein phosphatase 1 (PP1). We investigated the effects of GADD34 with or without the Q525X mutation on the phosphorylation status of PP1 target proteins, including the subunit of eukaryotic initiation factor 2 (eIF2) and glycogen synthase kinase 3 (GSK3). CHO-K1-G34M cells had higher levels of eIF2 phosphorylation compared to the control CHO-K1-normal cells both in the presence and absence of endoplasmic reticulum stress. Overexpression of the wild-type GADD34 protein in CHO-K1-normal cells largely reduced eIF2 phosphorylation, while overexpression of the Q525X mutant did not produce similar reductions. Meanwhile, neither wild type nor Q525X mutation of GADD34 affected the GSK3 phosphorylation status. GADD34 also did not affect the canonical Wnt signaling pathway downstream of GSK3. Cell proliferation rates were higher, while expression levels of the cyclin-dependent kinase inhibitor p21 were lower in CHO-K1-G34M cells compared to the CHO-K1-normal cells. The GADD34 Q525X mutant had a reduced ability to inhibit cell proliferation and enhance p21 expression of the CHO-K1-normal cells compared to the wild-type GADD34 protein. These results suggest that the GADD34 protein C-terminal plays important roles in regulating not only eIF2 dephosphorylation but also cell proliferation in CHO-K1 cells.


Role of transesophageal echocardiography during biventricular pacemaker implantation in children


特発性間質性肺炎を合併した患者に対する口腔外科長時間手術の全身麻酔経験

特発性間質性肺炎を合併した患者に対する口腔外科長時間手術の全身麻酔経験


静脈穿刺により発症した血管迷走神経性失神時に心拍変動解析を行った1例

静脈穿刺により発症した血管迷走神経性失神時に心拍変動解析を行った1例


Impact of newly developed, next-generation artificial endocrine pancreas

Recent studies have shown that strict perioperative blood glucose management may reduce mortality and morbidity in critically ill adult patients. The purpose of this study was to assess the accuracy and efficacy of the intraoperative application of a newly developed, next-generation artificial endocrine pancreas (STG-55, Nikkiso Co., Ltd., Tokyo, Japan). Twenty patients scheduled to undergo surgery were enrolled in this study. The STG-55 is designed to be more user-friendly than its conventional counterpart (STG-22) while maintaining the latter's fundamental functions, such as a closed-loop system using algorithms for insulin and glucose infusion. After anesthetic induction, a 20G intravenous catheter was inserted into a peripheral forearm vein and connected to a continuous blood glucose monitor. The resultant 105 scores for paired blood glucose values were compared by Bland-Altman analysis. Stable blood glucose values were maintained automatically, and there were no complications related to use of the STG-55. A close correlation (r=0.96) was observed between continuous glucose measurements using the STG-55 and conventional intermittent glucose measurements. The difficulty of manipulation using this system was decreased by improved preparation procedures. The glycemic control system using the STG-55 could provide an alternative way to achieve effective and safe perioperative glycemic control.

The Journal of Medical Investigation : JMI


Geranylgeranylacetone and volatile anesthetic-induced cardiac protection synergism is dependent on caveolae and caveolin-3.

Pharmacological preconditioning, including that with geranylgeranylacetone (GGA) and volatile anesthetics, has been shown to confer cardiac protection from ischemia/reperfusion injury although the mechanisms for this protection are poorly understood. Caveolins, integral membrane proteins that act as scaffolding proteins in caveolar membranes, localize molecules involved in cardiac protection. We have tested the hypothesis that caveolin-3 (Cav-3), the predominant isoform in cardiac myocytes, is essential for the synergistic effect observed between GGA and volatile anesthetics. Mice were randomly assigned to receive GGA, isoflurane [0.5 and 1.0 minimum alveolar concentration (MAC)], or GGA + isoflurane (0.5 MAC). An in vivo mouse model of ischemia/reperfusion injury was tested in wild-type and Cav-3 knockout mice, and the infarct size was determined. Biochemical assays were also performed in excised hearts. Geranylgeranylacetone and therapeutic isoflurane (1.0 MAC) independently reduced infarct size (31.6 ± 6.1 and 28.0 ± 5.0 % of the area at risk, respectively; n = 10) as compared to the controls (45.8 ± 9.4 %; n = 10). The combination GGA + sub-therapeutic isoflurane (0.5 MAC) further decreased the infarct size to 19.3 ± 5.1 % (n = 10). Preconditioning [GGA, isoflurane (1.0 MAC), and GGA + isoflurane] increased the amount of Cav-3 protein in the discontinuous sucrose-gradient buoyant fractions. Additionally, cardiac protection was not observed in Cav-3 knockout mice following the administration of GGA, isoflurane, and GGA + isoflurane. Combined administration of GGA + isoflurane had a synergistic effect, enhancing the protection against myocardial infarction to a greater extent than either drug alone. This beneficial effect is mediated by Cav-3 expression.


Cuffed oropharyngeal airway for difficult airway management.

Abstract Difficulties with airway management are often caused by anatomic abnormalities due to previous oral surgery. We performed general anesthesia for a patient who had undergone several operations such as hemisection of the mandible and reconstructive surgery with a deltopectoralis flap, resulting in severe maxillofacial deformation. This made it impossible to ventilate with a face mask and to intubate in the normal way. An attempt at oral awake intubation using fiberoptic bronchoscopy was unsuccessful because of severe anatomical abnormality of the neck. We therefore decided to perform retrograde intubation and selected the cuffed oropharyngeal airway (COPA) for airway management. We inserted the COPA, not through the patient's mouth but through the abnormal oropharyngeal space. Retrograde nasal intubation was accomplished with controlled ventilation through the COPA, which proved to be very useful for this difficult airway management during tracheal intubation even though the method was unusual.


Propofol-induced relaxation of rat aorta is altered by aging.

Propofol causes vasodilation via endothelium-dependent and -independent mechanisms. Because endothelial function is impaired with aging, the effects of propofol on endothelium-dependent vasodilation might be altered by aging. The aim of this study was thus to determine the effects of aging on vascular responses to propofol. Young (4-6 weeks old) or adult (16-25 weeks old) rats were anesthetized with sevoflurane. The thoracic aorta was dissected and cut into pieces 3-4 mm in length. In some rings, the endothelium was deliberately removed. The ring segment of the aorta was mounted for isometric force recording at a resting tension of 0.5-1.0 g in a 2 ml organ bath, containing Krebs-Ringer bicarbonate buffer. Arteries were precontracted with phenylephrine, and the function of endothelium was confirmed with acetylcholine. Then, we studied the concentration-dependent effects of propofol in endothelium-intact (control group) and -denuded aortic rings (denuded group), as well as those treated with N()-nitro-L-arginine methylester (L-NAME group). Relaxation due to propofol was observed in the control groups of both young and adult rats in a concentration-dependent manner, but the magnitude of relaxation was significantly greater in young rats. In addition, in young rats, relaxation due to propofol was significantly and equally reduced in both L-NAME and denuded groups at all propofol concentrations that we studied (10(-6)-10(-3) M). In adult rats, relaxation due to propofol was quite similar between control and L-NAME groups at all propofol concentrations, whereas it was significantly reduced in the denuded group. These results suggest that endothelium-derived nitric oxide plays an important role in propofol-induced vasodilation in young rats, but not in adult rats. J. Med. Invest. 61: 278-284, August, 2014.


Usefulness of artificial endocrine pancreas during resection of insulinoma.

A 71-year-old woman had an episode of syncope due to hypoglycemia of 27 mg/dl. She was diagnosed with insulinoma and scheduled for laparoscopic enucleation along with the use of an artificial endocrine pancreas (STG-22, Nikkiso Co., Ltd., Tokyo, Japan). Anesthesia was maintained with sevoflurane and remifentanil. Her blood glucose level was controlled using the artificial endocrine pancreas, which enabled continuous blood glucose monitoring and computer-operated glucose and insulin infusion to maintain the blood glucose level at a steady state. The target concentration of blood glucose was set at 80-120 mg/dl during surgery. Until removal of the tumor, the blood glucose level was kept at around 80-100 mg/dl. After removal of the tumor, the blood glucose level gradually increased, but it was kept in the normal range by the artificial endocrine pancreas. The artificial endocrine pancreas was useful to monitor and maintain blood glucose levels during and after the removal of insulinoma, without any hyper- or hypoglycemia. J. Med. Invest. 61: 421-425, August, 2014.

The Journal of Medical Investigation : JMI


Role of an intraoperative single-plane transesophageal echocardiography probe for infants with congenital heart disease


いわゆる病病連携による障害者歯科医療連携が奏功した集学的歯科治療について

いわゆる病病連携による障害者歯科医療連携が奏功した集学的歯科治療について


Increase in prominence of electrocardiographic J waves after a single dose of propofol in a patient with early ventricular repolarisation.

J waves appear on an electrocardiogram as an elevation of the J point in the terminal portion of the QRS complex. J waves are often benign, but may be associated with malignant ventricular arrhythmias. In some cases, such problems appear to have been precipitated by propofol infusions. We observed a sudden increase in J waves and profound hypotension following a single intravenous dose of propofol in an 84-year-old woman with early repolarisation in the inferior ventricular wall. When early repolarisation (as shown by electrocardiographic J waves) is observed in the inferior ventricular wall pre-operatively, patients should be carefully monitored. Myocardial ischaemia and the use of drugs that might worsen J waves should be avoided.


Novel blood sampling method of an artificial endocrine pancreas via the cardiopulmonary bypass circuit.

We tried to perform continuous blood glucose monitoring during cardiovascular surgery involving cardiopulmonary bypass using an artificial endocrine pancreas (STG-22 or -55; Nikkiso, Tokyo, Japan); however, we often encountered problems during these procedures because insufficient blood was obtained for monitoring. Thus, we started performing the blood sampling via the venous side of the cardiopulmonary bypass circuit. As a result, continuous blood glucose monitoring using an artificial endocrine pancreas was proven to be stable and reliable during cardiovascular surgery involving cardiopulmonary bypass.


Usefulness of central venous oxygen saturation monitoring during bidirectional Glenn shunt.

A PediaSat™ oximetry catheter (PediaSat: Edwards Lifesciences Co., Ltd., Irvine, CA, U. S. A.), which facilitates continuous measurement of central venous oxygen saturation (ScvO2), may be useful for surgery for pediatric congenital heart disease. We used PediaSat during a bidirectional Glenn shunt. The patient was a 13-month-old boy. Under a diagnosis of left single ventricle (pulmonary atresia, right ventricular hypoplasia, atrial septal defect) and residual left aortic arch/left superior vena cava, a modified right Blalock-Taussig shunt was performed. Cyanosis deteriorated, so a bidirectional Glenn shunt was scheduled. After anesthesia induction, a 4.5 Fr double-lumen (8 cm) PediaSat was inserted through the right internal jugular vein for continuous ScvO2 monitoring. Furthermore, the probe of a near-infrared, mixed blood oxygen saturation-measuring monitor was attached to the forehead for continuous monitoring of the regional brain tissue mixed blood oxygen saturation (rSO2) (INVOS™ 5100C, Covidien; Boulder, CO, U. S. A.). Blockage of the right pulmonary artery and right superior vena cava decreased the oxygen saturation, ScvO2, and rSO2, but increased the central venous pressure. Although changes in ScvO2 were parallel to those in rSO2, the former showed more marked changes. A combination of ScvO2 and rSO2 for monitoring during Glenn shunt may be safer.


Local anesthetics inhibit nitric oxide production and l-arginine uptake in cultured bovine aortic endothelial cells.

Previous studies have shown that local anesthetics have various effects on nitric oxide (NO) production, but the mechanisms remain unclear. The purpose of this study was to evaluate the effects of local anesthetics on NO production and 2-amino-5-guanidinopentanoic acid (l-arginine) uptake in one cell line. Cultured bovine aortic endothelial cells (BAEC) were stimulated with bradykinin and/or acetylcholine to activate endothelial NO synthase (NOS). BAEC were also incubated with interleukin-1β and lipopolysaccharide to stimulate inducible NOS. NO production was measured with the rapid spectrophotometric method, and l-arginine uptake was measured with high performance liquid chromatography. To assess the effects of local anesthetics, NO production and l-arginine uptake were measured in the presence or absence of procaine or lidocaine. NO was produced in BAEC stimulated with bradykinin and acetylcholine or interleukin-1β and lipopolysaccharide, but NO production was not affected by the addition of superoxide dismutase. In the cells stimulated with bradykinin and acetylcholine, 10 μM each of procaine and lidocaine significantly inhibited NO production by 35% and 20%, respectively. In the cells incubated with interleukin-1ß and lipopolysaccharide, the same quantities of procaine and lidocaine significantly inhibited NO production by 15% and 10%, respectively. Both procaine and lidocaine significantly suppressed l-arginine uptake in BAEC stimulated with either bradykinin/acetylcholine or interleukin-1β/lipopolysaccharide. It is suggested that inhibitory effects of procaine and lidocaine on NO production are partially due to suppression of l-arginine uptake.


Recent less-invasive circulatory monitoring during renal transplantation.

For anesthetic management during renal transplantation, it is necessary to maintain the blood flow and function of the transplanted kidney by performing massive fluid management and stabilizing blood pressure. We report anesthetic management for renal transplantation with a less-invasive circulatory monitoring system (Edwards Life Sciences Co., Ltd., Irvine, California, U.S.A.). In November 2010, renal transplantation was started in our hospital, and performed in 6 patients. In the first patient, fluid/circulatory management was conducted by connecting a standard arterial line and a standard central venous (CV) line. In the second patient, a FloTrac(TM) system and a standard CV line were used. In the third patient, a standard arterial line and a PreSep(TM) CV Oximetry Catheter were used. In the fourth and fifth patients, a FloTrac(TM) and a PreSep(TM) were used. In the latest patient, FloTrac(TM) and PreSep(TM) were connected to an EV1000(TM) Clinical Platform for fluid/circulatory management. The establishment of high-visibility monitors was useful for evaluating the condition and confirming the effects. As there are marked changes in hemodynamics, the CV pressure, which has been used as a parameter of fluid management, is not reliable in renal failure patients with a high incidence of cardiovascular complications. Advances in noninvasive circulatory monitoring with dynamic indices may improve the safety of anesthetic management during renal transplantation.

The Journal of Medical Investigation : JMI


Usefulness of continuous blood glucose monitoring and control for patients undergoing liver transplantation.

The STG-22 closed-loop system is effective for maintaining strict blood glucose control during liver transplantation with minimal variability in blood glucose concentration.


Anesthetic Management for Buccal Mucosa Tumor Resection in a Patient with Pemphigus Vulgaris

尋常性天疱瘡患者における頬粘膜腫瘍切除術の全身麻酔経験

Journal of Japanese Dental Society of Anesthesiology


Molecular mechanisms of the inhibitory effects of clonidine on vascular adenosine triphosphate-sensitive potassium channels.

We investigated the effects of the imidazoline-derived α2-adrenoceptor agonist clonidine on vascular adenosine triphosphate-sensitive potassium (K(ATP)) channel activity in rat vascular smooth muscle cells and recombinant vascular K(ATP) channels transiently expressed in COS-7 cells. Using the patch-clamp method, we investigated the effects of clonidine on the following: (1) native vascular K(ATP) channels; (2) recombinant K(ATP) channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits; (3) SUR-deficient channels derived from a truncated isoform of the Kir6.2 subunit (Kir6.2ΔC36 channels); and (4) mutant Kir6.2ΔC36 channels with diminished sensitivity to ATP (Kir6.2ΔC36-K185Q channels). Clonidine (≥3 × 10(-8) M) inhibited native K(ATP) channel activity in cell-attached configurations with a half-maximal inhibitory concentration value of 1.21 × 10(-6) M and in inside-out configurations with a half-maximal inhibitory concentration value of 0.89 × 10(-6) M. With similar potency, clonidine (10(-6) or 10(-3) M) also inhibited the activities of various recombinant SUR/Kir6.0 K(ATP) channels, the Kir6.2ΔC36 channel, and the Kir6.2ΔC36-K185Q channel. Clinically relevant concentrations of clonidine inhibit K(ATP) channel activity in vascular smooth muscle cells. This inhibition seems to be the result of its effect on the Kir6.0 subunit and not on the SUR subunit.


Anaesthesia for a patient with paraneoplastic limbic encephalitis with ovarian teratoma: relationship to anti-N-methyl-D-aspartate receptor antibodies.

Paraneoplastic limbic encephalitis associated with ovarian teratoma has recently been related to the development of antibodies to specific heteromers of the N-methyl-d-aspartate receptor and exhibits various manifestations including psychiatric symptoms, hypoventilation, seizures and derangement of autonomic nervous system function. Although recovery can sometimes occur spontaneously, early tumour resection with immunotherapy facilitates earlier recovery. Herein, we describe anaesthetic management of a 20-year-old woman who developed general convulsions and decreased level of consciousness, whom we suspected of having paraneoplastic limbic encephalitis and was scheduled for left ovarian tumour resection. Anaesthetic management was successful with no complications but the case acts as focus of discussion for the potential interaction of N-methyl-D-aspartate receptors and anaesthetic sensitivity.


小児感染性心内膜炎の周術期管理における心エコーの役割

小児感染性心内膜炎の周術期管理における心エコーの役割

The Japanese Journal of Pediatric Dentistry


A retrospective survey of conscious sedation used in children undergoing oral surgery or dental treatment during e ten-year period at the Tokushima University Hospital

小児患者の精神鎮静法に関する過去10年間の検討


Autologous Peripheral Blood Mononuclear Cell Implantation for Therapeutic Angiogenesis in a Patient with Buerger's Disease

バージャー病に対する自己末梢血単核球細胞移植による血管新生治療

The Journal of Japan Society for Clinical Anesthesia


Anesthetic management for repair of ebstein's anomaly with WPW syndrome

WPW症候群を合併したエプスタイン奇形の麻酔管理

Ebstein's anomaly is a rare congenital malformation of the tricuspid valve, often associated with Wolff-Parkinson-White (WPW) syndrome. We report the perioperative management of 3 patients (a 34-year-old man, a 5-month-old boy and a 5-year-old girl) with Ebstein's anomaly associated with WPW syndrome. Anesthetic managements for valvuloplasty of the tricuspid valve and ablation of accessory pathway in 3 patients were successfully accomplished with a combination of fentanyl, sevoflurane, and midazolam. The management of Ebstein's anomaly is based on its severity. The major concerns with anesthesia for children with Ebstein's anomaly include decreased cardiac output, right-to-left atrial level shunting with cyanosis, and the propensity for atrial tachyarrhythmias. We conclude that perioperative management of arrhythmia and evaluation of residual tricuspid regurgitation using transesophageal echocardiography are essential.


② 意外に難しいスライディング・スケール法による血糖管理 --- 人工膵臓を用いた外科手術周術期血糖管理法


小児先天性心疾患の最終診断のための経食道心エコー

小児先天性心疾患の最終診断のための経食道心エコー


Low-dose sevoflurane inhalation enhances late cardioprotection from the anti-ulcer drug geranylgeranylacetone.

We investigated in rabbits whether sevoflurane enhances late cardioprotection induced by geranylgeranylacetone (GGA), a gastric antiulcer drug. S(+)-ketamine and xylazine-anesthetized rabbits were assigned to one of seven experimental groups: a control (vehicle only) group, a GGA group, a sevoflurane group, a GGA+sevoflurane group, a sodium 5-hydroxydecanoate (5HD) group, a GGA + 5HD group, and a heat stress group. All rabbits were subjected to 30 min of coronary artery occlusion followed by 3 h of reperfusion. Rabbits were pretreated with IV vehicle, GGA (10 mg/kg), or heat stress (42 degrees C for 15 min) 24 h before coronary occlusion. Sevoflurane (0.5 minimum alveolar concentration) or 5HD (5 mg/kg) were administered before myocardial ischemia. Myocardial infarct size and the area at risk for ischemia were measured, and heat shock protein (Hsp) 70 levels in each experimental group were determined. Compared with vehicle only, GGA significantly reduced the size of myocardial infarction in relation to the area at risk (39 +/- 10% vs 59 +/- 9%, P < 0.02). Sevoflurane enhanced the GGA-induced cardioprotection (23 +/- 17%, P < 0.05 vs GGA). The cardioprotective effect of GGA was abolished by administration of 5HD (56 +/- 15%, P < 0.01). GGA enhanced Hsp 70 expression compared with that in the control group (0.69 +/- 0.15 vs 0.36 +/- 0.05, P < 0.02). Administration of GGA with sevoflurane resulted in the same level of Hsp 70 expression as GGA (0.69 +/- 0.16, P > 0.98). GGA appears to reduce myocardial infarct size in association with increased Hsp 70 expression. Sevoflurane enhances the GGA-induced cardioprotective effect.


Two unusual complications associated with cardiopulmonary bypass for pediatric cardiac surgery detected by transesophageal echocardiography after decannulation.

We describe two rare cases of complications associated with cannulation for cardiopulmonary bypass during pediatric cardiac surgery detected by transesophageal echocardiography (TEE). The first patient (a 20-month-old boy, 11 kg) was scheduled for complete repair of an atrial septal defect and partial anomalous pulmonary venous connection. After decannulation of the superior vena cava, a mosaic jet was observed by means of TEE. The second patient (an 11-month-old boy, 6.4 kg), with a double outlet right ventricle, was scheduled for a hemi-Fontan procedure. After decannulation of the ascending aorta, high blood flow velocity of 4 m x s(-1) was detected by TEE. Intraoperative TEE was useful for early detection of complications associated with cardiopulmonary bypass cannulation during pediatric cardiac surgery.


Intraoperative transesophageal ventricular pacing in pediatric patients.

Journal of Cardiothoracic and Vascular Anesthesia


Non-cardiac surgery applications of extracorporeal circulation

Although the efficacy of extracorporeal circulation (ECC) is well established for open-heart surgery, application of ECC in other surgical areas has not been given much attention. Advances in the related surgical technique and anesthetic management combined with refinements in the ECC procedure itself have encouraged several institutions to use ECC for complex non-cardiac surgeries. ECC is beginning to be used for circulatory support or tissue oxygenation during surgery on the lung, brain, liver, and kidney as well as in emergency situations. With ECC, difficult and complex surgeries can be performed more safely, and the success rate of certain surgeries has been positively affected. It is important that the surgeon, anesthesiologist, and perfusionist are trained in non-cardiac surgery applications of ECC. Thus, we review here non-cardiac uses that have emerged and summarize the related procedures.

The Journal of Medical Investigation : JMI


Differential Effects of Etomidate and Midazolam on Vascular Adenosine Triphosphate-sensitive Potassium Channels: Isometric Tension and Patch Clamp Studies.

The aim of this study was to investigate the effects of two imidazoline-derived intravenous anesthetics, etomidate and midazolam, on vascular adenosine triphosphate-sensitive potassium (KATP) channel activity. In isolated rat aorta, isometric tension was recorded to examine the anesthetic effects on vasodilator response to levcromakalim, a selective KATP channel opener. Using the patch clamp method, the anesthetic effects were also examined on the currents through (1) native vascular KATP channels, (2) recombinant KATP channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits, (3) SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit (Kir6.2DeltaC36 channels), and (4) mutant Kir6.2DeltaC36 channels with reduced sensitivity to adenosine triphosphate (Kir6.2DeltaC36-K185Q channels). Etomidate (> or = 10 m), but not midazolam (up to 10 m), inhibited the levcromakalim-induced vasodilation, which was sensitive to glibenclamide (IC50: 7.21 x 10 m; maximum inhibitory concentration: 1.22 x 10 m). Etomidate (> or = 3 x 10 m), but not midazolam (up to 10 m), inhibited the native KATP channel activity in both cell-attached and inside-out configurations with IC50 values of 1.68 x 10 m and 1.52 x 10 m, respectively. Etomidate (10 m) also inhibited the activity of various types of recombinant SUR/Kir6.0KATP channels, Kir6.2DeltaC36 channels, and Kir6.2DeltaC36-K185Q channels with equivalent potency. Clinical concentrations of etomidate, but not midazolam, inhibit the KATP channel activity in vascular smooth muscle cells. The inhibition is presumably through its effects on the Kir6.0 subunit, but not on the SUR subunit, with the binding site different from adenosine triphosphate at the amino acid level.


Usefulness of intraoperative transesophageal echocardiography in stent graft implantation for thoracic descending aorta

胸部下行大動脈ステントグラフト留置術における術中経食道心エコーの有用性

Stent graft implantation for thoracic descending aorta is a promising alternative to open repair. Transesophageal echocardiography (TEE) is a sensitive imaging modality for aortic disease. We reviewed our experience with TEE in stent graft implantation for thoracic descending aorta. Five patients underwent stent graft implantation for thoracic descending aorta under general anesthesia. Intraoperative angiography and TEE were used to identify the extent of the aneurysm and the placement of the stent. TEE showed stent graft configuration and presence of leakage in all cases. In three cases, additional stent graft placement or bypass was performed. Useful information was obtained by TEE in enhancing the accuracy of stent graft positioning potentially improving outcomes. TEE may facilitate repair by confirming aortic pathology, identifying endograft placement, and assessing the adequacy of aneurysm sack isolation, presence of leakage, as well as dynamic intraoperative cardiac performance.


Bronchospasm during anesthesia in a patient with Pena-Shokeir syndrome

気管支痙攣を繰り返したPena-Shokeir症候群の麻酔管理

A 3-month-old boy with Pena-Shokeir syndrome underwent tracheotomy under general anesthesia. Patients with this syndrome may present anesthetic problems involving difficulties in tracheal intubation, possibilities of malignant hyperthermia, as well as perioperative respiratory complications related to hypoplasia of the lung. General anesthesia was induced and maintained with sevoflurane (2-3%) and nitrous oxide (0-50%) in oxygen (50-100%). The patient developed bronchospasm during tracheotomy. Atropine and epinephrine were administered intravenously and 5% sevoflurane was inhaled. The bronchospasm was improved gradually and surgery was successfully finished. Pena-Shokeir syndrome is an uncommon disease first reported by Pena & Shokeir in 1974 and characterized by congenital multiple arthrogryposis, characteristic facies, camptodactyly and pulmonary hypoplasia. In the perioperative management for a patient with Pena-Shokeir syndrome, special attention should be paid to abnormalities in the upper and lower respiratory systems, especially bronchospasm.


きれいで正確な心エコー画像の描出 --- ー小児経食道心エコー画像を正しく描出するにはー


Minute distance obtained from pulmonary venous flow velocity using transesophageal pulsed Doppler echocardiography is related to cardiac output during cardiovascular surgery

We studied the relationship between minute distance calculated from pulmonary venous flow (PVF) velocity tracing and cardiac output (CO) measured with thermodilution method in patients undergoing cardiovascular surgery. In 32 patients undergoing cardiovascular surgery, simultaneous measurements of hemodynamics including CO and transesophageal pulsed Doppler signals of PVF velocity were performed before and after surgical repair. Minute distance was calculated as the product of the heart rate and the sum of time-velocity integrals of PVF. The minute distance after surgical intervention increased from 1121 +/- 347 cm x sec(-1) to 1764 +/- 538 cm x sec(-1) (p < 0.001; mean +/- SD), while CO increased after surgical intervention from 3.5 +/- 0.9 L x min(-1) to 5.3 +/- 1.1 L x min(-1). Simple linear regression analysis showed that minute distance was related with CO before and after surgical intervention (r = 0.81 and r = 0.76, respectively). The changes in minute distance were also related with those in CO (r = 0.80). The present study demonstrated that minute distance obtained from the pulsed Doppler tracings of PVF velocity was related with CO during cardiovascular surgery in adults. These results suggest that the changes in CO could be estimated from minute distance in pulmonary vein.


Involvement of adenosine triphosphate-sensitive potassium channels in the response of membrane potential to hyperosmolality in cultured human aorta endothelial cells.

The membrane potential of endothelial cells is an important determinant of endothelial functions, including regulation of vascular tone. We investigated whether adenosine triphosphate-sensitive potassium (K(ATP)) channels were involved in the response of membrane potential to hyperosmolality in cultured human aorta endothelial cells. The voltage-sensitive fluorescent dye, bis-(1,3-diethylthiobarbiturate)trimethine oxonol, was used to assess relative changes in membrane potential semiquantitatively. To investigate the effect of mannitol-, sucrose-, and NaCl-induced hyperosmolality on membrane potential, cells were continuously perfused with Earle's balanced salt solution (285 mOsm/kg H(2)O) containing 200 nM bis-(1,3-diethylthiobarbiturate)trimethine oxonol and exposed to 315 and 345 mOsm/kg H(2)O hyperosmotic medium sequentially in the presence and absence of 1 muM glibenclamide, a well-known K(ATP) channel blocker. Hyperosmotic mannitol significantly induced hyperpolarization of the endothelial cells, which was prevented by 1 microM glibenclamide (n = 6). Estimated changes of membrane potential at 315 and 345 mOsm/kg H(2)O were 13 +/- 8 and 21 +/- 8 mV, respectively. Hypertonic sucrose induced similar changes. However, although hypertonic saline also significantly induced hyperpolarization of the endothelial cells (n = 6), the hyperpolarization was not prevented by 1 muM glibenclamide. In conclusion, K(ATP) channels may participate in hyperosmotic mannitol- and sucrose-induced hyperpolarization, but not in hypertonic saline-induced hyperpolarization in cultured human aorta endothelial cells.


Molecular mechanisms underlying ketamine-mediated inhibition of sarcolemmal adenosine triphosphate-sensitive potassium channels.

Ketamine inhibits adenosine triphosphate-sensitive potassium (KATP) channels, which results in the blocking of ischemic preconditioning in the heart and inhibition of vasorelaxation induced by KATP channel openers. In the current study, the authors investigated the molecular mechanisms of ketamine's actions on sarcolemmal KATP channels that are reassociated by expressed subunits, inwardly rectifying potassium channels (Kir6.1 or Kir6.2) and sulfonylurea receptors (SUR1, SUR2A, or SUR2B). The authors used inside-out patch clamp configurations to investigate the effects of ketamine on the activities of reassociated Kir6.0/SUR channels containing wild-type, mutant, or chimeric SURs expressed in COS-7 cells. Ketamine racemate inhibited the activities of the reassociated KATP channels in a SUR subtype-dependent manner: SUR2A/Kir6.2 (IC50 = 83 microM), SUR2B/Kir6.1 (IC50 = 77 microM), SUR2B/Kir6.2 (IC50 = 89 microM), and SUR1/Kir6.2 (IC50 = 1487 microM). S-(+)-ketamine was significantly less potent than ketamine racemate in blocking all types of reassociated KATP channels. The ketamine racemate and S-(+)-ketamine both inhibited channel currents of the truncated isoform of Kir6.2 (Kir6.2DeltaC36) with very low affinity. Application of 100 mum magnesium adenosine diphosphate significantly enhanced the inhibitory potency of ketamine racemate. The last transmembrane domain of SUR2 was essential for the full inhibitory effect of ketamine racemate. These results suggest that ketamine-induced inhibition of sarcolemmal KATP channels is mediated by the SUR subunit. These inhibitory effects of ketamine exhibit specificity for cardiovascular KATP channels, at least some degree of stereoselectivity, and interaction with intracellular magnesium adenosine diphosphate.


Anesthetic management of a patient undergoing cardioverter defibrillator implantation: usefulness of transesophageal echocardiography and near infrared spectroscopy.


Molecular Mechanisms of the Inhibitory Effects of Bupivacaine, Levobupivacaine, and Ropivacaine on Sarcolemmal Adenosine Triphosphate-sensitive Potassium Channels in the Cardiovascular System.

Sarcolemmal adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system may be involved in bupivacaine-induced cardiovascular toxicity. The authors investigated the effects of local anesthetics on the activity of reconstituted KATP channels encoded by inwardly rectifying potassium channel (Kir6.0) and sulfonylurea receptor (SUR) subunits. The authors used an inside-out patch clamp configuration to investigate the effects of bupivacaine, levobupivacaine, and ropivacaine on the activity of reconstituted KATP channels expressed in COS-7 cells and containing wild-type, mutant, or chimeric SURs. Bupivacaine inhibited the activities of cardiac KATP channels (IC50 = 52 microm) stereoselectively (levobupivacaine, IC50 = 168 microm; ropivacaine, IC50 = 249 microm). Local anesthetics also inhibited the activities of channels formed by the truncated isoform of Kir6.2 (Kir6.2 delta C36) stereoselectively. Mutations in the cytosolic end of the second transmembrane domain of Kir6.2 markedly decreased both the local anesthetics' affinity and stereoselectivity. The local anesthetics blocked cardiac KATP channels with approximately eightfold higher potency than vascular KATP channels; the potency depended on the SUR subtype. The 42 amino acid residues at the C-terminal tail of SUR2A, but not SUR1 or SUR2B, enhanced the inhibitory effect of bupivacaine on the Kir6.0 subunit. Inhibitory effects of local anesthetics on KATP channels in the cardiovascular system are (1) stereoselective: bupivacaine was more potent than levobupivacaine and ropivacaine; and (2) tissue specific: local anesthetics blocked cardiac KATP channels more potently than vascular KATP channels, via the intracellular pore mouth of the Kir6.0 subunit and the 42 amino acids at the C-terminal tail of the SUR2A subunit, respectively.


Risk factors for perioperative myocardial ischemia in carotid artery endarterectomy.

To identify variables associated with perioperative myocardial ischemia in patients undergoing carotid artery endarterectomy (CEA). Prospective, observational study. University-affiliated hospital operating room and intensive care unit. One hundred twenty-eight consecutive patients who underwent CEA during a 7-year period. Patients had general anesthesia with sevoflurane or isoflurane. CEA was performed by standard methods with shunting if clinically indicated. Holter electrocardiogram (ECG) monitoring was performed during surgery and 24 hours after surgery. The incidence of perioperative myocardial ischemia was examined, and perioperative risk factors were analyzed. Nineteen patients (15%) showed significant perioperative ECG abnormalities indicative of myocardial ischemia (10 patients during surgery, 12 patients after surgery, and 3 patients both during and after surgery). Multivariate analysis showed perioperative myocardial ischemia to be significantly associated with a history of angina (odds ratio, 11.68; 95% confidence interval, 2.64-51.70) and a history of hypertension (odds ratio, 14.08; 95% confidence interval, 1.51-131.04). The data indicate that perioperative myocardial ischemia defined as an ECG abnormality does not often occur in patients undergoing CEA. However, angina and hypertension may be important risk factors warranting further investigation.

Journal of Cardiothoracic and Vascular Anesthesia


Effect of propofol on hypotonic swelling-induced membrane depolarization in human coronary artery smooth muscle cells.

Stretch (mechanical stress)-induced membrane depolarization of smooth muscle may contribute to basal vascular tone and myogenic control. Propofol induces vasodilation and inhibits myogenic control. Hypotonic swelling was used as a model of mechanical stress. The authors investigated the effects of propofol and 5-nitro-2-(3-phenylpropylamino)benzoic acid, a chloride channel and nonselective cation channel blocker, on hypotonicity-induced membrane depolarization in cultured human coronary artery smooth muscle cells. A voltage-sensitive fluorescent dye, bis-(1,3-diethylthiobarbiturate)trimethine oxonol, was used to assess relative changes in membrane potential semiquantitatively. The cells were continuously perfused with Earle's balanced salt solution containing 200 nM bis-(1,3-diethylthiobarbiturate)trimethine oxonol and exposed sequentially to isotonic and hypotonic medium. In a second series of experiments, the cells were exposed to hypotonic media in the presence and absence of 5-nitro-2-(3-phenylpropylamino)benzoic acid or propofol. The relative fluorescence values at 10, 20, and 30% hypotonicity were 147 +/- 29, 214 +/- 74, and 335 +/- 102% of baseline, respectively. The changes were all significantly different from the isotonic time control group. In the presence of 200 microM 5-nitro-2-(3-phenylpropylamino)benzoic acid or 0.1, 1, 10, or 100 microg/ml propofol, the relative fluorescence values at 30% hypotonicity were 87 +/- 17, 194 +/- 27, 160 +/- 18, 130 +/- 18, and 84 +/- 15%, respectively. These changes were significantly less than the 30% for the hypotonic control (246 +/- 23%). These results suggest that volume-sensitive chloride channels and nonselective cation channels may participate in hypotonicity-induced membrane depolarization and that propofol inhibits hypotonicity-induced membrane depolarization in coronary artery smooth muscle.


Molecular mechanisms of the inhibitory effects of propofol and thiamylal on sarcolemmal adenosine triphosphate-sensitive potassium channels.

Both propofol and thiamylal inhibit adenosine triphosphate-sensitive potassium (KATP) channels. In the current study, the authors investigated the effects of these anesthetics on the activity of recombinant sarcolemmal KATP channels encoded by inwardly rectifying potassium channel (Kir6.1 or Kir6.2) genes and sulfonylurea receptor (SUR1, SUR2A, or SUR2B) genes. The authors used inside-out patch clamp configurations to investigate the effects of propofol and thiamylal on the activity of recombinant KATP channels using COS-7 cells transfected with various types of KATP channel subunits. Propofol inhibited the activities of the SUR1/Kir6.2 (EC50 = 77 microm), SUR2A/Kir6.2 (EC50 = 72 microm), and SUR2B/Kir6.2 (EC50 = 71 microm) channels but had no significant effects on the SUR2B/Kir6.1 channels. Propofol inhibited the truncated isoform of Kir6.2 (Kir6.2DeltaC36) channels (EC50 = 78 microm) that can form functional KATP channels in the absence of SUR molecules. Furthermore, the authors identified two distinct mutations R31E (arginine residue at position 31 to glutamic acid) and K185Q (lysine residue at position 185 to glutamine) of the Kir6.2DeltaC36 channel that significantly reduce the inhibition of propofol. In contrast, thiamylal inhibited the SUR1/Kir6.2 (EC50 = 541 microm), SUR2A/Kir6.2 (EC50 = 248 microm), SUR2B/Kir6.2 (EC50 = 183 microm), SUR2B/Kir6.1 (EC50 = 170 microm), and Kir6.2DeltaC36 channels (EC50 = 719 microm). None of the mutants significantly affects the sensitivity of thiamylal. These results suggest that the major effects of both propofol and thiamylal on KATP channel activity are mediated via the Kir6.2 subunit. Site-directed mutagenesis study suggests that propofol and thiamylal may influence Kir6.2 activity by different molecular mechanisms; in thiamylal, the SUR subunit seems to modulate anesthetic sensitivity.


Phenylephrine increases pulmonary blood flow in children with tetralogy of Fallot.

Although it has been reported that the increase in blood pressure improves arterial oxygen saturation (SaO(2)) in children with tetralogy of Fallot, no prospective study has demonstrated that an increase in blood pressure induces an increase in pulmonary blood flow in these patients. The purpose of this study was to see whether a phenylephrine-induced increase in systemic blood pressure increased pulmonary blood flow, resulting in improved arterial oxygenation in tetralogy of Fallot. In 14 consecutive children with tetralogy of Fallot (2-32 months old), transesophageal pulsed Doppler signals of left upper pulmonary venous flow (PVF) velocity were recorded before and four minutes after 10 micro g x kg(-1) of phenylephrine i.v. Simultaneously, arterial blood gas analysis and hemodynamic measurements were performed. The minute distance (MD) was calculated as the product of the heart rate and the sum of time-velocity integrals of PVF. Phenylephrine iv increased mean arterial blood pressure from 54 +/- 8 mmHg to 73 +/- 10 mmHg. This phenylephrine-induced hypertension significantly increased SaO(2) and MD (92.0 +/- 7.5 vs 95.0 +/- 5.0% and 1318 +/- 344 vs 1533 +/- 425 cm x min(-1), respectively). There was a significant correlation (r = 0.72) between the change in MD and the change in SaO(2). Our results suggest that the phenylephrine-induced increase in systemic blood pressure produces an increase in pulmonary blood flow in tetralogy of Fallot. Our results further suggest that this increase in pulmonary blood flow is involved in the mechanism of phenylephrine-induced improvement of arterial oxygenation in tetralogy of Fallot.


Intraoperative transoesophageal echocardiography in a low birth weight neonate with atrioventricular septal defect.

An 18-day-old male neonate (45 cm, 1.8 kg) with a history of cyanosis and congestive heart failure from an atrioventricular septal defect (AVSD) with a large left-to-right shunt was scheduled for surgical repair of the AVSD. After routine induction of anaesthesia with fentanyl and vecuronium, a 4.5-mm diameter transoesophageal echocardiography (TOE) probe was inserted into the oesophagus, and systematic echocardiographic evaluation was performed during surgery. After cardiopulmonary bypass was stopped, intraoperative TOE revealed mild residual mitral valve regurgitation. Because good left ventricular wall motion was confirmed and haemodynamic parameters were stable, cardiopulmonary bypass was not reinitiated. The patient's cardiac output was low in the postoperative intensive care unit. TOE was performed the next day to detect the source of this problem, revealed severe regurgitation compared with that observed intraoperatively. TOE was useful for evaluation of the residual mitral valve regurgitation, and we reconfirmed the importance of continuous monitoring even in a low birthweight neonate undergoing repair of a complete AVSD.


Propofol inhibits volume-sensitive chloride channels in human coronary artery smooth muscle cells.

Volume-sensitive chloride channels (VSCC) play an important role in regulation of cell volume and electrical activity. Activation of vascular smooth muscle VSCC causes smooth muscle depolarization and contraction. We investigated the effects of propofol on VSCC in cultured human coronary artery smooth muscle cells by using the chloride-sensitive dye 6-methoxy-N-ethylquinolinium (MEQ). To activate VSCC, cells were superfused for 2 min with hypotonic gluconate solutions and then potassium thiocyanate solution. The percentage reduction in MEQ fluorescence during 60 s in the presence of potassium thiocyanate was measured and used as an index of VSCC activity. 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), a well characterized chloride channel blocker, and propofol were dissolved in hypotonic gluconate solution to test their effect on VSCC activity. The reduction in fluorescence was inversely related to osmolality, indicating that activation of VSCC is osmolality dependent. Hypotonic gluconate solution (210 mOsm/kg H(2)O) reduced fluorescence by 38.9% +/- 2.6% of the baseline value. The reduction in fluorescence was dose-dependently inhibited by NPPB. Propofol at 0.3, 1, 3, 10, 30, and 100 micro g/mL significantly inhibited the reduction in fluorescence to 23.6% +/- 4.8%, 19.7% +/- 7.4%, 18.2% +/- 3.5%, 17.6% +/- 5.0%, 15.8% +/- 3.1%, and 10.3% +/- 3.9% of the baseline value, respectively. Our results indicate that propofol inhibits VSCC in a dose-dependent manner in human coronary artery smooth muscle cells.


Dynamic QRS-complex and ST-segment monitoring by continuous vectorcardiography during carotid endarterectomy.

Many authors report a high incidence of cardiac events during carotid endarterectomy. The aim of the present study was to evaluate the usefulness of dynamic continuous on-line vectorcardiography for monitoring the occurrence of myocardial ischaemia during carotid endarterectomy. We studied 21 patients undergoing carotid endarterectomy. Patients underwent general anaesthesia with isoflurane or sevoflurane. The vectorcardiogram was monitored continuously during carotid endarterectomy. Electrodes were placed according to the previously described lead system and connected to a computerized system for on-line vectorcardiography. Two trend variables were recorded: the QRS vector difference, which reflects changes in the shape of the QRS complex; and the ST vector magnitude, which represents deflection of the ST segment from the isoelectric level. The ST segment deflection was measured 60 ms after termination of the QRS complex. Vectorcardiography was successfully recorded in all 21 patients. Three patients showed intraoperative vectorcardiogram abnormalities. In one of these three patients, both ST vector magnitude and QRS vector difference increased after induction of anaesthesia and ST vector magnitude returned to baseline after administration of nitroglycerin. In the other two patients, both ST vector magnitude and QRS vector difference gradually increased after cross-clamping of the internal carotid artery and ST vector magnitude returned to baseline after unclamping. QRS vector difference remained elevated for several hours in all three patients. Monitoring ST vector magnitude and QRS vector difference by vectorcardiography may be useful for identifying myocardial ischaemia during carotid endarterectomy.


Effects of acute normovolemic hemodilution on ventriculoarterial coupling in dogs.

Acute normovolemic hemodilution (ANH) causes a decrease in systemic vascular resistance. Similar to vasodilating drugs, ANH might modify ventriculoarterial coupling. Left ventricular elastance (Ees), effective arterial elastance (Ea), stroke work (SW), and pressure volume area (PVA) were used as indicators to examine the effects of ANH on this coupling. After institutional approval eight dogs were anesthetized with isoflurane and subjected to measurements including aortic pressure, left ventricular (LV) pressure, and LV volume. Left ventricular volume was measured with a conductance catheter. Ees was determined as the slope of the end-systolic pressure-volume relationship. Ea was determined as the ratio of LV end-systolic pressure to stroke volume. Ventriculoarterial coupling was evaluated as the ratio of Ees to Ea. Mechanical efficiency, another criterion for ventriculoarterial coupling, was calculated as the ratio of SW to PVA. Data are expressed as mean+/-SD, and P<0.05 was considered significant. Normovolemic exchange of 50 ml kg-1 of blood for 6% hydroxyethyl starch (ANH50) reduced hemoglobin concentration from 12.8+/-3.0 g dl-1 to 6.4+/-1.3 g dl-1. Acute normovolemic hemodilution 50 did not change Ees significantly although it significantly decreased Ea. Left ventricular elastance/Ea did not change after ANH (1.0+/-0.4 at baseline and 1.2+/-0.5 at ANH50). Acute normovolemic hemodilution 50 significantly increased SW and PVA, preventing SW/PVA from changing significantly after ANH (0.57+/-0.10 at baseline and 0.62+/-0.14 at ANH50). Before ANH, ventriculoarterial coupling was so matched as to maximize SW at the expense of the work efficiency. This relation was preserved at ANH50.


Clinically relevant concentrations of propofol have no effect on adenosine triphosphate-sensitive potassium channels in rat ventricular myocytes.

Activation of adenosine triphosphate-sensitive potassium (K(ATP)) channels produces cardioprotective effects during ischemia. Because propofol is often used in patients who have coronary artery disease undergoing a wide variety of surgical procedures, it is important to evaluate the direct effects of propofol on K(ATP) channel activities in ventricular myocardium during ischemia. The effects of propofol (0.4-60.1 microg/ml) on both sarcolemmal and mitochondrial K(ATP) channel activities were investigated in single, quiescent rat ventricular myocytes. Membrane currents were recorded using cell-attached and inside-out patch clamp configurations. Flavoprotein fluorescence was measured to evaluate mitochondrial oxidation mediated by mitochondrial K(ATP) channels. In the cell-attached configuration, open probability of K(ATP) channels was reduced by propofol in a concentration-dependent manner (EC(50) = 14.2 microg/ml). In the inside-out configurations, propofol inhibited K(ATP) channel activities without changing the single-channel conductance (EC(50) = 11.4 microg/ml). Propofol reduced mitochondrial oxidation in a concentration-dependent manner with an EC(50) of 14.6 microg/ml. Propofol had no effect on the sarcolemmal K(ATP) channel activities in patch clamp configurations and the mitochondrial flavoprotein fluorescence induced by diazoxide at clinically relevant concentrations (< 2 microm), whereas it significantly inhibited both K(ATP) channel activities at very high, nonclinical concentrations (> 5.6 microg/ml; 31 microm).


The effects of acute normovolemic hemodilution on left ventricular systolic and diastolic function in the absence or presence of beta-adrenergic blockade in dogs.

Acute normovolemic hemodilution (ANH) increases cardiac output because of a reduction in blood viscosity and enhancement of left ventricular (LV) contractility. The status of LV function, especially LV diastolic function during ANH, remains controversial. We therefore examined LV systolic and diastolic function during ANH. Sixteen dogs were anesthetized with isoflurane in the absence (Group 1) and presence (Group 2) of beta-adrenergic blockade (propranolol 1 mg/kg). LV contractility was quantified by the slope (M(w)) of the stroke work and end-diastolic volume relation. Diastolic function was evaluated with the time constant of LV relaxation (T), chamber stiffness constant (K(c)), peak LV diastolic filling rate during early filling (peak E) and atrial contraction (peak A), and ratio of peak E to peak A (E/A). Normovolemic exchange of blood (50 mL/kg) for 6% hydroxyethyl starch (ANH50) significantly increased M(w) in Group 1 but not in Group 2. In both groups, ANH50 significantly decreased T. ANH50 significantly increased peak E in both groups and peak A in Group 1, and it did not change the E/A ratio or K(c) in either group. ANH causes positive inotropic effects and enhances diastolic function without beta-blockade. Even after beta-adrenergic blockade, ANH improves diastolic function through the reduction of LV ejection impedance. IMPLICATIONS: Acute normovolemic hemodilution enhances LV (left ventricular) diastolic function by alterations in the LV loading condition produced by hemodilution, which mainly contributes to a compensatory increase in cardiac output.


Lidocaine and mexiletine inhibit mitochondrial oxidation in rat ventricular myocytes.

Accumulating evidence suggests that mitochondrial rather than sarcolemmal adenosine triphosphate-sensitive K+ (K(ATP)) channels may have an important role in the protection of myocardium during ischemia. Because both lidocaine and mexiletine are frequently used antiarrhythmic drugs during myocardial ischemia, it is important to investigate whether they affect mitochondrial K(ATP) channel activities. Male Wistar rats were anesthetized with ether. Single, quiescent ventricular myocytes were dispersed enzymatically. The authors measured flavoprotein fluorescence to evaluate mitochondrial redox state. Lidocaine or mexiletine was applied after administration of diazoxide (25 microM), a selective mitochondrial K(ATP) channel opener. The redox signal was normalized to the baseline flavoprotein fluorescence obtained during exposure to 2,4-dinitrophenol, a protonophore that uncouples respiration from ATP synthesis and collapses the mitochondrial potential. Diazoxide-induced oxidation of flavoproteins and the redox changes were inhibited by 5-hydroxydecanoic acid, a selective mitochondrial K(ATP) channel blocker, suggesting that flavoprotein fluorescence can be used as an index of mitochondrial oxidation mediated by mitochondrial K(ATP) channels. Lidocaine (10(-3) to 10 mM) and mexiletine (10(-3) to 10 mM) reduced oxidation of the mitochondrial matrix in a dose-dependent manner with an EC50 of 98+/-63 microM for lidocaine and 107+/-89 microM for mexiletine. Both lidocaine and mexiletine reduced flavoprotein fluorescence induced by diazoxide in rat ventricular myocytes, indicating that these antiarrhythmic drugs may produce impairment of mitochondrial oxidation mediated by mitochondrial K(ATP) channels.


Pulmonary arterial pressure can be estimated by transesophageal pulsed Doppler echocardiography.

We examined whether pulmonary arterial pressure can be estimated on the basis of pulmonary arterial flow velocity determined via intraoperative pulsed Doppler transesophageal echocardiography (TEE) in 20 patients undergoing cardiac surgery. Standard pulmonary artery measurements were taken as well. Measurements were taken before sternotomy, after pericardiotomy, after cardiopulmonary bypass, and after sternum closure. The variables obtained by TEE included preejection period (PEP), acceleration time (AT), right ventricular ejection time (RVET), and R-R interval (RR). Five ratios were calculated as indices of pulmonary arterial pressure--PEP/AT, PEP/RVET, AT/RVET, PEP/ square root of RR, and AT/ square root of RR--and were compared with pulmonary artery catheterization findings, i.e., systolic pulmonary arterial pressure (sPAP), log sPAP, mean PAP (mPAP), and log mPAP. Before sternotomy, PEP/AT, PEP/ square root of RR, and AT/ square root of RR showed significant correlation with all pulmonary artery catheterization values. AT/RVET showed correlation with all pulmonary artery values except log mPAP. PEP/AT showed the closest correlation with sPAP (r = 0.771) and log sPAP (r = 0.789). PEP/AT also showed close correlation with mPAP (r = 0.764) and log mPAP (r = 0.777). Significant agreement between sPAP and mPAP values calculated from a regression equation and values measured via pulmonary artery catheter was observed by plotting the differences against the mean values of the two measurements. We therefore conclude that noninvasive estimation of pulmonary arterial pressure is feasible via intraoperative TEE when sternotomy is not involved.


Bronchospasm induced by cardiopulmonary bypass.

Annals of Thoracic and Cardiovascular Surgery


Intraoperative evaluation of pulmonary artery flow during the Fontan procedure by transesophageal Doppler echocardiography.

After the Fontan procedure, pulmonary artery (PA) flow is maintained without right ventricular pump function. We evaluated intraoperative PA flow velocity patterns using transesophageal Doppler echocardiography (TEE) immediately after cardiopulmonary bypass (CPB) in patients during Fontan or hemi-Fontan procedures. We studied 10 patients with single-ventricle physiology (age range, 5 mo to 3 yr 1 mo). Anesthesia was induced and maintained with fentanyl. After induction of anesthesia, a pediatric TEE probe was inserted into the esophagus. All patients had surgical repair involving direct anastomosis of the right atrium to the PA. Immediately after completion of CPB, adequacy of the atriopulmonary anastomosis was assessed and PA flow velocity was recorded. In all patients, the atriopulmonary anastomosis was clearly defined using a single-plane TEE probe, and PA flow recording was completed successfully. Intraoperative PA flow velocities showed two distinct patterns. Biphasic forward flows with peak velocities during systole and diastole were observed in six patients. The remaining four patients showed forward flows with flow reversals. The four patients demonstrating flow reversals showed significantly reduced fractional shortening (26.5+/-2.1% vs. 35.5+/-6.3%) and larger pressure gradient between the right atrium and left atrium (10.8+/-1.3 mm Hg vs 8.0+/-0.9 mm Hg) when compared to those without reverse flow. Two patients with reverse flow required reoperation because of hypotension. Because PA flow is influenced by pulmonary vascular resistance and left ventricular function, TEE assessed intraoperative PA flow should be further evaluated as a useful predictor of surgical outcome after a Fontan procedure.


Cyclic variation of integrated ultrasound backscatter in the left ventricle during the early neonatal period.

Significant changes in the contractility and histologic structure of the ventricular myocardium occur during the early neonatal period. Cyclic variation (CV) of ultrasonic integrated backscatter (IBS) reflects myocardial contractile performance. The aim of this study was to define normal values of and its serial changes in CV of IBS in the left ventricle of normal neonates. We recorded long-axis IBS images in 169 healthy neonates within 14 days after birth (mean 4.6 +/- 4.2 days) and in 84 infants and children (mean age 8.7 +/- 5.2 years). For each, we obtained CV of IBS in the interventricular septum (CV(IVS)) and the posterior wall (CV(PW)). In neonates, there was a significant linear correlation between CV and date after birth in measurements of both the interventricular septum and the posterior wall (r = 0.57 and 0. 60, respectively). In infants and children, there was no significant relation between age and CV(IVS) or CV(PW). In neonates >4 days after birth, the magnitude of CV(IVS) was not significantly different from that in infants or children. By contrast, the magnitude of CV(PW) was still significantly decreased in neonates >9 days after birth compared with that in infants and children (P <. 005). The ratio of CV(IVS) to CV(PW) (CV(IVS)/CV(PW)) was significantly higher in neonates than in infants and children (0.99 +/- 0.29 vs 0.80 +/- 0.22, P <.001). Both CV(IVS) and CV(PW) in neonates gradually increase after birth, indicating developmental maturation of the left ventricle. High values of CV(IVS)/CV(PW) might reflect the remnant of relatively high contractile performance in the right ventricle during fetal life.


Transesophageal echocardiography for intraoperative management of the fenestrated Fontan procedure.

Journal of Cardiothoracic and Vascular Anesthesia


Transesophageal echocardiographic assessment of pulmonary arterial and venous flow during high-frequency jet ventilation.

To evaluate high-frequency jet ventilation (HFJV) effects on pulmonary arterial and venous flow compared to those of intermittent positive-pressure ventilation (IPPV) by using pulsed Doppler transesophageal echocardiography. Prospective clinical study. University-affiliated hospital operating room.Patients: 13 ASA physical status I and II patients undergoing lower abdominal or lower extremity surgery. Patients had total IV anesthesia with propofol and fentanyl. After anesthesia induction, a transesophageal echocardiography probe was inserted into the esophagus. IPPV (TV, 8-10 mL/kg; respiratory rate, 10-12 cycles/min; I/E ratio, 1:2; FIO(2), 1.0) and HFJV (driving pressure, 0.5-0.6 kgf/cm(2); frequency,3 Hz; I/E ratio, 1:1; FIO(2), 1.0) were performed under hemodynamically stable conditions. Pulmonary-arterial-flow velocity, pulmonary-venous-flow velocity, left ventricular short-axis view, and airway-pressure curve were recorded simultaneously. Parameters measured were: hemodynamic variables, arterial blood gases, inspiratory airway pressure; [from pulmonary-arterial-flow velocity] pre-ejection period (PEP), acceleration time (AT), right ventricular ejection time (RVET), and their ratios (PEP/AT, AT/RVET); [from pulmonary-venous-flow velocity] time-velocity integral of the first systolic wave (S1), second systolic wave (S2), and diastolic wave (D), and systolic fraction (integral S1 + S2/S1+ S2 + D); [from M-mode] left-ventricular-end systolic volume, left-ventricular-end diastolic volume (LVEDV), stroke volume, cardiac output, and ejection fraction, using Teichholz's method. Peak inspiratory airway pressure during HFJV was significantly lower than that during IPPV. HFJV significantly decreased PEP/AT, correlating positively with pulmonary arterial pressure, and significantly increased AT and AT/RVET, correlating negatively with pulmonary arterial pressure. Systolic fraction, correlating negatively with left atrial pressure, increased significantly during HFJV, as did LVEDV, stroke volume, cardiac output, and ejection fraction. Our results suggest that, in comparison to IPPV, HFJV significantly decreases pulmonary arterial pressure and left atrial pressure, resulting in significant increases in cardiac output and ejection fraction in healthy anesthetized adults.


Blockade of adenosine triphosphate-sensitive potassium channels by thiamylal in rat ventricular myocytes.

The adenosine triphosphate (ATP)-sensitive potassium (KATP) channels protect myocytes during ischemia and reperfusion. This study investigated the effects of thiamylal on the activities of KATP channels in isolated rat ventricular myocytes during simulated ischemia. Male Wistar rats were anesthetized with ether. Single, quiescent ventricular myocytes were dispersed enzymatically. Membrane currents were recorded using patch-clamp techniques. In the cell-attached configuration, KATP channel currents were assessed before and during activation of these channels by 2,4-dinitrophenol and after administration of 25, 50, and 100 mg/l thiamylal. The open probability was determined from current-amplitude histograms. In the inside-out configuration, the current-voltage relation was obtained before and after the application of thiamylal (50 mg/1). In the cell-attached configuration, 2,4-dinitrophenol caused frequent channel opening. 2,4-Dinitrophenol-induced channel activities were reduced significantly by glibenclamide, suggesting that the channels studied were KATP channels. Open probability of KATP channels was reduced by thiamylal in a concentration-dependent manner. KATP channels could be activated in the inside-out configuration because of the absence of ATP. Thiamylal inhibited KATP channel activity without changing the single-channel conductance. The results obtained in this study indicate that thiamylal inhibits KATP channel activities in cell-attached and inside-out patches, suggesting a direct action of this drug on these channels.


Nitric oxide does not play a major role in the regulation of systemic hemodynamic responses to acute normovolemic hemodilution.

The mechanisms of cardiovascular changes following acute normovolemic hemodilution (ANH) have not been fully elucidated. We tested the hypothesis that inhibition of nitric oxide synthesis attenuates ANH-induced cardiovascular responses. We observed the effects of N(omega)-nitro-L-arginine methyl ester (L-NAME) pretreatment on ANH-induced cardiovascular responses and compared these effects with those elicited by phenylephrine (PHE). Twenty dogs anesthetized with isoflurane were divided into two groups: one group was pretreated with L-NAME and the other with PHE. Both groups were normovolemically hemodiluted using 6% hydroxyethyl starch to reduce the hemoglobin concentration to approximately 50% of the pretreatment value. Pretreatment with either L-NAME or PHE caused a significant increase in mean aortic blood pressure (MAP) and systemic vascular resistance (SVR) with a significant decrease in cardiac output (CO) and stroke volume (SV). However, no remarkable differences in these variables were seen between groups. In both groups ANH produced increases in heart rate, CO, SV, and maximal left ventricular dP/dt with a significant decrease in SVR. No significant differences in these variables were apparent after ANH except that MAP was decreased in the PHE group but not in the L-NAME group. Our results suggest that nitric oxide does not play a major role in mediation or modulation of the systemic vascular responses to ANH.


Recurrent laryngeal nerve palsy after cardiovascular surgery --- Relationship to the placement of a transesophageal echocardiographic probe

To examine the relationship between the incidence of recurrent laryngeal nerve palsy after cardiovascular surgery and the placement of a transesophageal echocardiographic probe. A prospective clinical study. A single-institutional study in a university hospital. One hundred sixteen patients undergoing cardiovascular surgery. All patients were assigned into one of two groups: 64 patients in whom transesophageal echocardiography (TEE) was performed and 52 patients in whom TEE was not performed during surgery. The incidence of recurrent laryngeal nerve palsy was examined and compared between the two groups. Five of 64 patients (7.8%) in whom TEE was monitored and 3 of 52 patients (5.8%) in whom TEE was not monitored were diagnosed with recurrent laryngeal nerve palsy postoperatively. There was no statistically significant difference between the incidence of recurrent laryngeal nerve palsy in patients with intraoperative TEE monitoring, and patients without it. The durations of surgery, anesthesia, and cardiopulmonary bypass were significantly longer in patients with nerve palsy than those without it. These results suggest that placement of the transesophageal echocardiographic probe is not responsible for postoperative recurrent laryngeal nerve palsy. It seems likely that surgical manipulation itself and the durations of surgery, cardiopulmonary bypass, and tracheal intubation are related to the incidence of laryngeal nerve palsy.


Autotransfusion performed on a patient with cis AB blood group.

Cis AB blood group is a rare variant of the AB blood group resulting from inheritance of both A and B genes on one chromosome. It may lead to misclassification in ABO grouping and clinical misdiagnosis as a result of its divergence from the laws of Landsteiner and Mendel. We encountered a case of cis AB blood group, and we found that autotransfusion was useful during surgery in this patient with a rare blood group.


Pulmonary hemodynamics --- Intraoperative assessment with transesophageal Doppler echocardiography


The feasibility of gastrothoracic ventricular pacing during transesophageal echocardiography.

We evaluated whether ventricular pacing is possible using pacing electrodes attached to a transesophageal echocardiography (TEE) probe in 20 patients undergoing elective cardiovascular surgery. A bipolar pacing lead was fixed with silicone adhesive anteriorly to the TEE probe with the distal electrode 25 mm from the TEE probe tip. The TEE probe was positioned to obtain a transgastric short-axis view of the left ventricle. The distal or proximal electrode on the TEE probe was the cathode; the chest electrode placed at the V5 lead position was the anode. Gastrothoracic ventricular pacing (GVP) was performed at 100 bpm at 30- or 50-ms pulse duration. Transgastric ventricular pacing (TVP) was also attempted using both TEE probe electrodes alternately as cathode/anode. Maximal generator output was 32 mA. GVP with the distal electrode as cathode was successful in 75% and 80% of patients at 30- and 50-ms pulse durations and 23.3+/-5.8 mA and 22.6+/-5.8 mA threshold currents, respectively. However, success rates (20% and 25%, respectively) were significantly lower with the proximal electrode as cathode using the same pulse durations and 14.4+/-5.3 mA and 16.7+/-6.8 mA threshold currents. The TVP success rate was significantly lower than that for GVP. With optimization, this system could become an available technique for intraoperative emergency ventricular pacing. Using an endocardial pacing lead attached to a transesophageal echocardiography probe, gastrothoracic ventricular pacing can be performed successfully without complications in 75%-80% of patients undergoing cardiovascular surgery.


Intraoperative management of a pediatric patient undergoing cardiac tumor resection with the aid of transesophageal and epicardial echocardiography.


effects of sevoflurane on regional myocardial blood flow distribution --- Quantification with myocardial contrast echocardiography

Using myocardial contrast echocardiography, the authors tried to determine whether sevoflurane causes myocardial blood maldistribution in humans and dogs. In animal experiments, 15 mongrel dogs were organized into dipyridamole (n = 6) and sevoflurane (n = 9) groups. Sonicated albumin was infused into the left main coronary artery. The peak gray level corrected for background was analyzed at the following intervals: (1) at baseline, (2) after stenosis of the left circumflex coronary artery (blood flow reduced by 40%), (3) after administration of dipyridamole (1 mg/kg given intravenously) or sevoflurane (1 minimum alveolar concentration) during stenosis, and (4) after phenylephrine during stenosis and administration of dipyridamole or sevoflurane. In human studies, nine patients undergoing coronary artery bypass grafting were studied. During partial extracorporeal circulation, the peak gray level was analyzed before and 20 min after sevoflurane (1 minimum alveolar concentration). In animal experiments, dipyridamole decreased significantly the inner:outer ratio of the peak gray level in the ischemic area and the ischemic:normal ratio of the peak gray level. After arterial pressure was restored with phenylephrine, neither the inner:outer ratio nor the ischemic:normal ratio improved. In contrast, after sevoflurane administration, the inner:outer ratio and the ischemic:normal ratio remained unchanged, but these increased with phenylephrine. In human studies, sevoflurane did not change the inner:outer ratio in the area supplied by the most stenotic coronary artery. These results suggest that dipyridamole, a potent coronary vasodilator, produces maldistribution of coronary blood flow in our dog models, whereas sevoflurane does not do this in animal or human studies.


Simultaneous transesophageal echocardiography and atrial pacing for intraoperative management of mitral regurgitation.


Anaesthetic management of a patient with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis.

A case of a patient associated with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis is presented. Williams syndrome is a rare disease associated with a characteristic facies, supravalvular aortic stenosis, and mental retardation. A 15-yr-old girl with Williams syndrome underwent aortoplasty for supravalvular aortic stenosis. Anaesthesia was induced with fentanyl and thiamylal, and maintained with nitrous oxide, oxygen, sevoflurane, and continuous intravenous infusion of fentanyl. Supravalvular aortic stenosis was evaluated using a multiplane transesophageal echocardiography (TEE) probe before and after repair. Multiplane TEE was found to be very useful for anaesthetic management in a patient with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis.


Effects of nicardipine on ventriculo-arterial coupling in humans.

The ratio of effective arterial elastance (Ea) to left ventricular elastance (Ees) is an indicator of the coupling between ventricular properties and arterial load properties. Another criterion for the coupling between an energy source and its load is the principle of economical fuel consumption, or mechanical efficiency, which is defined as the ratio of stroke work (SW) to myocardial oxygen consumption per beat (MVO2). It has been revealed that SW of ventricular contraction is maximized when Ea/Ees = 1, while mechanical efficiency is maximized when Ea/Ees = 0.5. The purpose of the present study was to investigate the ventriculo-arterial coupling during hypertension, and the effects of nicardipine on this relationship in surgical patients using Ea/Ees and SW/MVO2 as indicators. Anaesthesia was maintained with isoflurane, nitrous oxide, and fentanyl. Radial artery pressure was displayed on a polygraph, and left ventricular end-systolic and end-diastolic volumes were determined by use of transoesophageal echocardiography. Ees was calculated as MAP/(ESVI-4), where MAP is mean arterial pressure and ESVI is end-systolic volume index. Ea was calculated as the ratio of MAP to stroke volume index (SVI). Stroke work index (SWI) was calculated as the product of MAP and SVI. MVO2 was assessed by estimating the ventricular pressure-volume area index (PVAI), which is expressed as the sum of SWI and the end-systolic potential energy index. Before (baseline), and 3, 10, 20, and 30 min after i.v. nicardipine (30 micrograms kg-1), Ea/Ees and SWI/PVAI were determined in 14 surgical patients with intraoperative hypertension. Before nicardipine (during hypertension), Ea was almost equal to Ees, whereas Ea/Ees was significantly reduced to about 0.5-0.6 at 3, 10, and 20 min after nicardipine. SWI/PVAI was maximized and significantly greater than the baseline value at 3 min after nicardipine. These results suggest that, during hypertension, ventricular and arterial properties were so matched as to maximize SW at the expense of the work efficiency, whereas mechanical efficiency of ventricular contraction was maximized after nicardipine.


Role of left atrial appendage in left atrial reservoir function as evaluated by left atrial appendage clamping during cardiac surgery.


Intraoperative contrast transesophageal echocardiography using Albunex.


A case of pulmonary arteriovenous fistula in which venous air embolism during cesarean section may have caused postoperative subendocardial infarction.


Effect of Gabexate mesilate on postoperative blood loss in cardiovascular surgery using cardiopulmonary bypass.


Left ventricular diastolic filling during coronary artery bypass surgery in patients with diabetes mellitus and/or hypertension.


Hemodynamic effects of high-frequency ventilation in dogs with acute right coronary arterial ligation and pulmonary arterial banding.

The hemodynamic effects of high-frequency jet ventilation (HFJV), synchronized with diastole, and intermittent positive-pressure ventilation (IPPV) were studied in 10 dogs with acute right-sided myocardial ischemia and elevated right ventricular pressure. Myocardial ischemia was produced by ligation of the proximal right coronary artery (RCA), then the right ventricular pressure was elevated to facilitate the ischemia by banding the main pulmonary artery. Before and 1, 2, 3, and 5 hr after the RCA ligation, cardiorespiratory variables for each ventilatory mode and creatine phosphokinase MB isoenzyme (CPK-MB) were measured. During HFJV compared with IPPV: there were significant increases in stroke index and left ventricular stroke work index at all ischemic periods, and decreases in peak and mean airway pressures and pulmonary vascular resistance at all ischemic periods, and in the product of systolic right ventricular pressure and heart rate at 2 hr, 3 hr, and 5 hr. The difference in mean airway pressure between IPPV and HFJV correlated significantly with those in cardiac index and stroke index (r = 0.575 and 0.779, respectively). CPK-MB was significantly greater at 3 hr and 5 hr than that before RCA ligation. These findings suggest that HFJV synchronized with diastole offers hemodynamic advantages over IPPV to ischemic right ventricle with constricted pulmonary artery, mainly due to lowering the mean airway pressure.


Left ventricular diastolic function using transesophageal Color Flow Doppler.


Quantitative analysis of transmitral flow and a preliminary study of pulmonary vein flow.

International Journal of Cardiac Imaging


Postoperative cardiac complications in patients with a history of myocardial infarction.

The Tokushima Journal of Experimental Medicine


血管新生に及ぼす麻酔薬と周術期管理法の影響

血管新生に及ぼす麻酔薬と周術期管理法の影響


Roles of left atrial appendage for left atrial hemodynamics by left atrial appendage clamping during cardiac surgery.


徳島大学病院における手術前日・当日入院システムの紹介

徳島大学病院における手術前日・当日入院システムの紹介