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1.
Nature ; 534(7607): 374-7, 2016 06 16.
Article in English | MEDLINE | ID: mdl-27281197

ABSTRACT

Interplate megathrust earthquakes have inflicted catastrophic damage on human society. Such an earthquake is predicted to occur in the near future along the Nankai Trough off southwestern Japan--an economically active and densely populated area in which megathrust earthquakes have already occurred. Megathrust earthquakes are the result of a plate-subduction mechanism and occur at slip-deficit regions (also known as 'coupling' regions), where friction prevents plates from slipping against each other and the accumulated energy is eventually released forcefully. Many studies have attempted to capture distributions of slip-deficit rates (SDRs) in order to predict earthquakes. However, these studies could not obtain a complete view of the earthquake source region, because they had no seafloor geodetic data. The Hydrographic and Oceanographic Department of the Japan Coast Guard (JHOD) has been developing a precise and sustainable seafloor geodetic observation network in this subduction zone to obtain information related to offshore SDRs. Here, we present seafloor geodetic observation data and an offshore interplate SDR-distribution model. Our data suggest that most offshore regions in this subduction zone have positive SDRs. Specifically, our observations indicate previously unknown regions of high SDR that will be important for tsunami disaster mitigation, and regions of low SDR that are consistent with distributions of shallow slow earthquakes and subducting seamounts. This is the first direct evidence that coupling conditions might be related to these seismological and geological phenomena. Our findings provide information for inferring megathrust earthquake scenarios and interpreting research on the Nankai Trough subduction zone.

2.
Masui ; 62(4): 426-30, 2013 Apr.
Article in Japanese | MEDLINE | ID: mdl-23697194

ABSTRACT

Intravenous patient-controlled analgesia (iv-PCA) has a great advantage for pain control in the postoperative period with occasional disadvantages of postoperative nausea and vomiting, which should be treated appropriately. Droperidol is commonly used as anti-emetic drug, but it also has a potential risk to induce extrapyramidal reactions. We report three patients who showed extrapyramidal reactions among 589 patients after droperidol administration. Although this complication is rare, we should be aware of the possible extrapyramidal reactions due to droperidol.


Subject(s)
Analgesia, Patient-Controlled/adverse effects , Antiemetics/adverse effects , Basal Ganglia Diseases/chemically induced , Droperidol/adverse effects , Adolescent , Antiemetics/administration & dosage , Droperidol/administration & dosage , Humans , Infusions, Intravenous , Male , Young Adult
3.
J Gen Psychol ; 150(2): 212-233, 2023.
Article in English | MEDLINE | ID: mdl-34542019

ABSTRACT

The purpose of this study was to assess whether self-imagery is more effective than other-imagery, and if so, to investigate the mechanism of how self-imagery generates more increased positive responses from consumers. Furthermore, we explored the boundary conditions associated with reduced positive effects of self-imagery on consumer responses. The results of Experiment 1 suggest that self-imagery was more effective than other-imagery in generating a favorable attitude toward an advertisement and purchase intention, since it enhanced a sense of presence, and consequently, imagery engagement. However, based on the results of Experiment 2, when an advertisement evoked a sense of high-risk, self-imagery generated a less favorable attitude toward the advertisement than other-imagery due to the emotion of fear evoked by the advertisement.


Subject(s)
Advertising , Attitude , Humans , Advertising/methods , Fear
4.
J Physiol ; 590(4): 827-44, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22183729

ABSTRACT

Voltage-gated proton channels play crucial roles during the respiratory burst in phagocytes, such as microglia. As local anaesthetics have a variety of anti-inflammatory properties, including inhibition of phagocytosis, they may act on the proton channels. Most local anaesthetics are tertiary amines and may affect proton channels through modification of pH(i) as weak bases. To test these hypotheses, the effects of lidocaine and bupivacaine on proton channels were examined in a rat microglial cell line (GMI-R1) as a function of pH(o) and pH(i). Both lidocaine and bupivacaine reversibly decreased the current, with IC(50) values of Ć¢ĀˆĀ¼1.2 and Ć¢ĀˆĀ¼0.5 mM, respectively, at pH(o)/pH(i) 7.3/5.5. The inhibition was enhanced with either pH(o) increase or pH(i) decrease, suggesting that the protonation of the base forms inside the cell contributed to the inhibitory effects. Both local anaesthetics shifted the reversal potentials to more positive voltages, indicating increases in pH(i). The potencies of inhibition were correlated well with the degree of increase in pH(i). The lidocaine-induced inhibition was eliminated when the pH(i) increases were cancelled by co-application of a weak acid, butyrate. The cytosolic alkalizations by lidocaine and bupivacaine were confirmed using a pH-sensitive fluorescent dye, BCECF, in non-voltage-clamped cells. Furthermore, chemiluminescence measurement proved that both anaesthetics inhibited production of reactive oxygen species by the cells. In conclusion, lidocaine and bupivacaine inhibit proton channels primarily by the weak base mechanism via an increase in pH(i). This is a novel mechanism underlying actions of local anaesthtics.


Subject(s)
Anesthetics, Local/pharmacology , Bupivacaine/pharmacology , Ion Channels/drug effects , Lidocaine/pharmacology , Protons , Animals , Cell Line , Hydrogen-Ion Concentration , Ion Channels/physiology , Microglia/drug effects , Microglia/physiology , Rats , Reactive Oxygen Species/metabolism
5.
Masui ; 60(7): 846-9, 2011 Jul.
Article in Japanese | MEDLINE | ID: mdl-21800666

ABSTRACT

Airway compromise is one of the greatest concerns in the anesthetic management in Hunter syndrome. We report anesthetic management of three cases of Hunter syndrome. The first was a 3-year-old boy scheduled for laparoscopic inguinal hernia repair. A laryngeal mask airway (LMA) was inserted and fiberoptic intubation through the LMA was successfully performed. The second was a 23-year-old man with a past history of difficult intubation, scheduled for repair of femur neck fracture. He received lateral cutaneous nerve block and monitored anesthesia care using remifentanil. The third was a 53-year-old man scheduled for repair of giant inguinal hernia. Having failed regional (combined spinal and epidural) anesthesia, we administered general anesthesia with placement of a LMA. Manual assisted ventilation was needed during operation due to unideal fit. The difficulty of airway management in Hunter syndrome is thought to increase with age. The airway obstruction is one of the most essential problems for anesthesia in these patients. It is important to assess the airway carefully, and to make plans for the anesthesia.


Subject(s)
Airway Management , Anesthesia , Mucopolysaccharidosis II/surgery , Child, Preschool , Femoral Neck Fractures/surgery , Hernia, Inguinal/surgery , Humans , Male , Middle Aged , Perioperative Care , Young Adult
6.
Masui ; 60(2): 220-3, 2011 Feb.
Article in Japanese | MEDLINE | ID: mdl-21384662

ABSTRACT

A 69-year-old man who has mitral stenosis concomitantly with dilated cardiomyopathy underwent mitral valve replacement. The preoperative left ventricular ejection fraction was 23%. Preoperative dobutamine stress echocardiography showed poor response. High dose fentanyl was administered for induction and maintenance of general anesthesia, and blood pressure was kept with vasoconstrictors. Circulatory assist with milrinone and intraaortic balloon pumping after the cardiopulmonary bypass enabled us to obtain stable hemodynamics.


Subject(s)
Anesthesia, General , Cardiomyopathy, Dilated/complications , Heart Valve Prosthesis Implantation , Mitral Valve Stenosis/surgery , Mitral Valve/surgery , Aged , Cardiopulmonary Bypass , Humans , Intra-Aortic Balloon Pumping , Male , Milrinone , Mitral Valve Stenosis/complications , Treatment Outcome
7.
Masui ; 60(6): 743-52, 2011 Jun.
Article in Japanese | MEDLINE | ID: mdl-21710778

ABSTRACT

BACKGROUND: Recently, the hospital information systems (HIS) and anesthesia information management systems (AIMS) have been rapidly improved and have been introduced into the clinical practice in Japan drastically; however, few reports have detailed their influences on clinical practice. We here report our experience. METHODS: We introduced HIS (EGMAIN-EX, Fujitsu Co., Ltd.) in our preoperative evaluation clinic and in the postoperative care unit. AIMS (ORSYS, Philips Electronics Japan) was introduced almost only to the intraoperative management. RESULTS: It became easy for us to acquire patient's information and to share it with the medical staffs in the other departments. However, we had to invest large human resources for the introduction and maintenance of the HIS and the AIMS. CONCLUSIONS: Though AIMS is more useful in anesthetic management than HIS, it seems to be more suitable for coordination with the medical staffs in the other departments to use HIS for perioperative management than to use AIMS.


Subject(s)
Anesthesia , Hospital Information Systems , Hospitals, University , Information Management , Perioperative Care , Hospital Information Systems/trends , Information Management/trends , Japan
8.
Anesthesiology ; 112(6): 1396-403, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20460991

ABSTRACT

BACKGROUND: We have compared the pharmacokinetics and brain distribution of lidocaine, racemic bupivacaine (bupivacaine), and levobupivacaine in awake, spontaneously breathing rats. METHODS: Lidocaine (0.5 mg x kg x min), bupivacaine (0.1 mg x kg x min), or levobupivacaine (0.1 mg x kg x min) was continuously administered to rats for 2 h (n = 12, each anesthetic). Blood samples and cerebral dialysate were collected during infusion and for 2 h after termination of infusion. Concentrations of anesthetics in the cerebral extracellular fluid were measured by microdialysis using the retrodialysis calibration method. Tissue-to-plasma partition coefficients calculated from the total (protein-bound and unbound) and unbound concentrations in plasma and brain as well as pharmacokinetic parameters in plasma and cerebral extracellular fluid were compared among the three anesthetics. RESULTS: There were no differences in plasma total or unbound concentrations between bupivacaine and levobupivacaine. Concentrations of bupivacaine in the cerebral extracellular fluid were significantly higher than levobupivacaine (P < 0.001). Despite no differences in the ratio of total brain concentration to total plasma concentration among the three anesthetics, the ratio of cerebral extracellular fluid concentration to plasma unbound fraction of bupivacaine was significantly higher than lidocaine and levobupivacaine (0.58 +/- 0.09, 0.47 +/- 0.18, and 0.40 +/- 0.09, respectively; P = 0.03 and 0.003, respectively). CONCLUSIONS: Although the ratio of total brain concentration to total plasma concentrations of lidocaine, bupivacaine, and levobupivacaine was similar, concentration ratio of bupivacaine in the cerebral extracellular fluid to plasma unbound fraction was significantly higher than lidocaine and levobupivacaine.


Subject(s)
Brain/metabolism , Bupivacaine/blood , Lidocaine/blood , Wakefulness/physiology , Animals , Brain/drug effects , Bupivacaine/analogs & derivatives , Bupivacaine/pharmacokinetics , Dose-Response Relationship, Drug , Extracellular Fluid/drug effects , Extracellular Fluid/metabolism , Levobupivacaine , Lidocaine/pharmacokinetics , Male , Rats , Rats, Sprague-Dawley , Wakefulness/drug effects
9.
J Anesth ; 24(2): 161-7, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20186436

ABSTRACT

PURPOSE: We examined the hypothesis that remifentanil decreases the bispectral index (BIS) as well as blunts cardiovascular responses to tracheal intubation during anesthesia with midazolam. METHODS: Sixty patients were randomly allocated to three groups according to the dose of remifentanil-0.1 (S), 0.2 (M), or 0.5 (L) microg kg(-1) min(-1), respectively. Infusion of remifentanil was started 5 min before the induction of general anesthesia with midazolam 0.2 mg/kg in all groups. Following the administration of vecuronium 0.1 mg/kg, the trachea was intubated 5 min after induction, and the infusion rate of remifentanil was then reduced to 0.05 microg kg(-1) min(-1) in all groups. Mean arterial blood pressure (MAP), heart rate (HR), BIS, and 95% spectral edge frequency (SEF95) were measured until 10 min after tracheal intubation. RESULTS: Infusion of remifentanil alone before the induction of anesthesia did not affect the hemodynamic or electroencephalographic parameters. MAP was significantly decreased after induction in all groups of patients (P < 0.01), with no differences among the three groups, while it was significantly increased after tracheal intubation in the patients of groups S and M, but not in those of group L. The HR did not change after induction in any of the groups, but it was also significantly increased after tracheal intubation of group S and M patients, although not in those of group L. The BIS decreased after induction, and both the BIS and SEF95 were significantly lower in group L patients than in those of group S (P < 0.01). All patients were unconscious after induction, and none complained of intraoperative awareness. CONCLUSION: In our patient cohort, remifentanil 0.5 microg kg(-1) min(-1) effectively decreased the BIS after the induction of general anesthesia with midazolam 0.2 mg/kg and suppressed the increase of MAP and HR in response to subsequent laryngoscopy and tracheal intubation.


Subject(s)
Adjuvants, Anesthesia , Analgesics, Opioid/pharmacology , Blood Pressure/drug effects , Electroencephalography/drug effects , Heart Rate/drug effects , Midazolam , Piperidines/pharmacology , Analgesics, Opioid/administration & dosage , Cohort Studies , Female , Humans , Intubation, Intratracheal , Laryngoscopy , Male , Middle Aged , Monitoring, Intraoperative , Piperidines/administration & dosage , Remifentanil
10.
J Anesth ; 24(3): 386-93, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20229000

ABSTRACT

PURPOSE: To examine the relationships between effect-site concentrations and electroencephalographic parameters after the induction of general anesthesia with midazolam. METHODS: Twenty-four patients with American Society of Anesthesiologists status I or II were randomly allocated to receive either an intravenous (i.v.) bolus of midazolam 0.2 mg kg(-1) (small-dose group, n = 12) or 0.3 mg kg(-1) (large-dose group, n = 12) for induction of general anesthesia in a double-blind experimental design. The bispectral index (BIS), 95% spectral edge frequency (SEF95), spectral power density, and plasma concentrations of midazolam were measured for 60 min following the induction of general anesthesia. RESULTS: Plasma and simulated effect-site concentrations of midazolam were significantly higher in the large-dose group than in the small-dose group (P = 0.005 and <0.001, respectively). There was a correlation between the relative beta ratio and BIS (r (2) = 0.30, P < 0.001; n = 168); however, effect-site concentrations of midazolam showed no association with BIS, relative beta ratio, or SEF95 (r (2) = 0.07, 0.11 and 0.01, respectively; n = 168). The electroencephalographic spectral power density in the beta-band (>/=13 and <30 Hz) was significantly increased after induction and was significantly larger in the large-dose group than in the small-dose group (P = 0.009). CONCLUSION: Following the induction of general anesthesia with i.v. midazolam 0.2 or 0.3 mg kg(-1), the BIS was positively correlated with the relative beta ratio. Despite a rapid decrease in the plasma and effect-site concentrations of midazolam, the average BIS remained >60 for 60 min after induction, reflecting an increased power of the electroencephalographic high-frequency band.


Subject(s)
Anesthesia, General , Anesthetics, Intravenous , Electroencephalography/drug effects , Midazolam , Aged , Algorithms , Anesthetics, Intravenous/administration & dosage , Anesthetics, Intravenous/blood , Area Under Curve , Dose-Response Relationship, Drug , Female , Half-Life , Humans , Male , Midazolam/administration & dosage , Midazolam/blood , Middle Aged , Monitoring, Intraoperative
11.
Masui ; 59(6): 721-3, 2010 Jun.
Article in Japanese | MEDLINE | ID: mdl-20560373

ABSTRACT

A patient developed prolonged apnea after emergency cesarean section. The patient was a 38-year-old primiparous woman with myoma uteri and her body weight was 44.8 kg. She received intravenous magnesium sulfate 1 g x hr(-1) as tocolytic agent for threatened premature delivery. We performed rapid sequence induction of anesthesia with thiopental 250 mg and rocuronium 50 mg because she was suspected of full stomach. After the intubation, we did not administer any muscle relaxants during the operation. After the operation which was finished in 65 minutes, the effect of rocuronium remained for more than 100 minutes after its administration probably due to hypermagnesemia. Rocuronium shows rapid onset, and several studies indicate that it can be used for rapid sequence induction instead of suxamethonium. But rocuronium should be used carefully and its effect should be monitored in a patient with hypermagnesemia.


Subject(s)
Androstanols/adverse effects , Anesthesia, General , Anesthesia, Obstetrical , Apnea/etiology , Cesarean Section , Magnesium Sulfate/adverse effects , Magnesium/blood , Tocolytic Agents/adverse effects , Adult , Emergencies , Female , Humans , Pregnancy , Rocuronium , Time Factors
12.
Masui ; 59(10): 1294-7, 2010 Oct.
Article in Japanese | MEDLINE | ID: mdl-20960907

ABSTRACT

We report a 39-year-old woman who showed intraoperative anaphylactic shock during elective cesarean section in the 38th week of pregnancy. She underwent cesarean sections under general anesthesia at 33 years of age, and under spinal anesthesia at 37 years without any complication; other past history was unremarkable. Spinal anesthesia was performed with 0.5% hyperbaric bupivacaine 2.5 ml and analgesia level up to T2 was obtained 12 minutes later. The operation was uneventful at the birth of a neonate weighing 2700 g delivered with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. Drip infusion of oxytocin was started after the delivery and uterine contraction was good. Five minutes later, blood pressure decreased abruptly to 70/40 mmHg, heart rate increased to 130 beats min(-1) and the patient complained of chest discomfort. Bolus injections of ephedrine and phenylephrine were ineffective, and continuous infusion of adrenaline was started to maintain blood pressure. The operation was finished and the patient was intubated for artificial ventilation to prevent airway obstruction. The tracheal tube was removed the following day and the postoperative course was uneventful thereafter. Plasma tryptase levels at 1 and 6 hours after the episode of hypotension were 9.0 and 1.3 ng x ml(-1). Postoperative blood tests revealed an increase in latex-specific immunoglobulin E, suggesting that anaphylactic shock was induced by latex.


Subject(s)
Anaphylaxis/etiology , Cesarean Section , Latex Hypersensitivity/complications , Adult , Female , Humans , Intraoperative Complications
13.
Masui ; 59(2): 206-9, 2010 Feb.
Article in Japanese | MEDLINE | ID: mdl-20169959

ABSTRACT

An 82-year-old man underwent thoracoscopic upper lobectomy of the left lung for the treatment of the lung cancer. The major complication was asymptomatic chronic trifascicular block. During the surgery, after the upper lobe had been resected, second degree atrioventricular block (Morbitz type II) occurred unexpectedly, soon evolving in complete AV block, with pulse wave disappearing, indicating pulseless electrical activity. Immediately, we used an epicardial pacing wire, and spontaneous circulation returned. Postoperatively, a permanent pacemaker was implanted. Asymptomatic chronic bifascicular block and trifascicular block rarely progress into complete AV block during operation, which we should be prepared in advance. Accordingly in some cases, preoperative insertion of a temporary pacemaker should be considered as a preventive measure.


Subject(s)
Atrioventricular Block , Heart Arrest , Heart Block/complications , Intraoperative Complications , Aged, 80 and over , Atrioventricular Block/etiology , Atrioventricular Block/prevention & control , Atrioventricular Block/therapy , Chronic Disease , Heart Arrest/etiology , Heart Arrest/prevention & control , Heart Arrest/therapy , Humans , Intraoperative Complications/etiology , Intraoperative Complications/prevention & control , Intraoperative Complications/therapy , Lung Neoplasms/complications , Lung Neoplasms/surgery , Male , Pacemaker, Artificial , Pneumonectomy , Preoperative Care , Thoracoscopy
14.
Masui ; 58(5): 623-5, 2009 May.
Article in Japanese | MEDLINE | ID: mdl-19462803

ABSTRACT

A 74-year-old woman was scheduled for a hepatectomy. Delayed emergence from anesthesia was anticipated because she had renal failure and liver dysfunction. We induced and maintained anesthesia for 478 minutes with propofol and remifentanil. The intraoperative course was uneventful and emergence from anesthesia was not delayed. Spontaneous respiration returned and her trachea was extubated 15 minutes after the surgery. Postoperative analgesia was established by epidural ropivacaine. This case shows that remifentanil is effective in anesthetic management for a patient with renal failure and liver dysfunction undergoing hepatectomy due to its unique mode of metabolism.


Subject(s)
Anesthesia, General , Hepatectomy , Liver Cirrhosis/complications , Liver Neoplasms/complications , Liver Neoplasms/surgery , Piperidines , Renal Insufficiency/complications , Aged , Female , Humans , Remifentanil
15.
Masui ; 58(4): 477-9, 2009 Apr.
Article in Japanese | MEDLINE | ID: mdl-19364015

ABSTRACT

A 67-year-old man was scheduled for resection of thoracic intramedullary tumor. His blood type was AB. Unexpectedly rapid and massive hemorrhage occurred during the operation. We infused a large amount of crystalloid, colloid, and 5% albumin. But he went into circulatory collapse before we could get type AB red blood cell (RBC) and hemoglobin was reduced to 3.8 g x dl(-1). We decided to transfuse 4 units of ABO incompatible type O RBC. Later, type AB RBC and other blood components became available and the patient recovered. We conclude that transfusion of ABO incompatible blood in patient with critical hemorrhage should be encouraged to save life.


Subject(s)
ABO Blood-Group System , Blood Group Incompatibility , Blood Loss, Surgical , Erythrocyte Transfusion , Intraoperative Complications/therapy , Aged , Humans , Male , Thoracic Neoplasms/surgery , Treatment Outcome
16.
Anesth Analg ; 107(6): 1946-52, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19020142

ABSTRACT

BACKGROUND: The involvement of reactive oxygen species early in the development of surgical stress and injury is highly suspected but has not been confirmed. Medical approaches to manage this type of oxidative stress are unknown. METHODS: We measured levels of blood hydroperoxides as an index of oxidative injury of cellular components, as well as plasma ferric-reducing ability as an index of total antioxidant potential, during sigmoidectomy under four conditions: open sigmoidectomy with sevoflurane anesthesia, laparoscopic sigmoidectomy with sevoflurane anesthesia, open sigmoidectomy with propofol anesthesia, and laparoscopic sigmoidectomy with propofol anesthesia. RESULTS: Ferric-reducing ability decreased significantly during surgery for the open sigmoidectomy with sevoflurane anesthesia, by 387 +/- 153 mmol/L, though the hydroperoxides level did not change, showing that oxidative stress increases in surgical patients. However, its toxicity may not be high enough to injure cellular components, since hydroperoxides, which are typical oxidized products of cellular components, did not increase. There were no changes in the hydroperoxides level or the ferric-reducing ability for the laparoscopic sigmoidectomy with sevoflurane anesthesia, indicating that this procedure does not increase surgical oxidative stress. Only hydroperoxides decreased significantly at the end of surgery for the open sigmoidectomy with propofol anesthesia and laparoscopic sigmoidectomy with propofol anesthesia, by 120 +/- 73 and 144 +/- 107 UCarr (1 UCarr corresponds to 0.8 mg/L H(2)O(2)), respectively. CONCLUSIONS: It seems certain that open abdominal surgery of the intestinal tract increases intraoperative oxidative stress. A laparoscopic procedure was not associated with oxidative stress, and propofol anesthesia reduced it by apparently functioning as an antioxidant.


Subject(s)
Abdomen/surgery , Oxidative Stress , Aged , Hemoglobins/analysis , Humans , Intraoperative Period , Laparoscopy , Methyl Ethers/pharmacokinetics , Middle Aged , Reactive Oxygen Species/metabolism , Sevoflurane
17.
Anesth Analg ; 106(5): 1450-5, table of contents, 2008 May.
Article in English | MEDLINE | ID: mdl-18420859

ABSTRACT

BACKGROUND: Propranolol is a beta-adrenoceptor antagonist used clinically. Local anesthetics are used for controlling pain, whereas propranolol is concomitantly given to treat hypertension and tachycardia. However, there are few studies examining the effects of propranolol on the toxicity of local anesthetics. We investigated the effect of propranolol on lidocaine-induced convulsions in awake, spontaneously breathing rats. METHODS: Male Sprague-Dawley rats were randomly divided into six groups (n = 8, each group). Rats were pretreated with intracerebroventricular saline (cerebroventricle-control: CV-C group), 10 or 30 microg/kg of (S)-(-)-propranolol (propranolol) (cerebroventricle-small dose: CV-S and cerebroventricle-large dose: CV-L groups, respectively) or i.v. saline (IV-control: IV-C group), 1 or 3 mg/kg of propranolol (IV-small dose: IV-S and IV-large dose: IV-L groups, respectively). Three minutes later, lidocaine was administered i.v. at 4 mg x kg(-1) x min(-1) until tonic-clonic convulsions occurred. RESULTS: The convulsive dose of lidocaine in the CV-L group was significantly larger than that in the CV-C group (30.6 +/- 5.1 vs 23.5 +/- 2.2 mg/kg, respectively, P = 0.008). Plasma concentrations of total and protein-unbound lidocaine, concentrations of lidocaine in the brain at the onset of convulsions were also significantly higher in the CV-L group than those in the CV-C group (36.1 +/- 4.8 vs 26.0 +/- 3.8 microg/mL, 22.5 +/- 3.5 vs 13.7 +/- 2.6 microg/mL, 82.7 +/- 7.1 vs 57.3 +/- 5.7 microg/g, P < 0.001 for all). The convulsive dose, plasma concentrations of total and protein-unbound lidocaine, and brain lidocaine in the IV-L group were also significantly larger than those in IV-C group and comparable with those in the CV-L group. The plasma concentration of propranolol before starting an infusion of lidocaine in the IV-L group was approximately 60-fold higher than that in the CV-L group (554.7 +/- 104.6 and 9.3 +/- 6.7 ng/mL, respectively). CONCLUSIONS: Propranolol increased the threshold for lidocaine-induced convulsions by directly acting on the brain.


Subject(s)
Adrenergic beta-Antagonists/pharmacology , Anesthetics, Local/toxicity , Anticonvulsants/pharmacology , Brain/drug effects , Lidocaine/toxicity , Propranolol/pharmacology , Seizures/prevention & control , Adrenergic beta-Antagonists/administration & dosage , Adrenergic beta-Antagonists/blood , Anesthetics, Local/administration & dosage , Anesthetics, Local/blood , Animals , Anticonvulsants/administration & dosage , Anticonvulsants/blood , Brain/metabolism , Dose-Response Relationship, Drug , Drug Interactions , Hemodynamics/drug effects , Infusions, Intravenous , Injections, Intraventricular , Lidocaine/administration & dosage , Lidocaine/blood , Male , Propranolol/administration & dosage , Propranolol/blood , Protein Binding , Rats , Rats, Sprague-Dawley , Seizures/chemically induced , Wakefulness
18.
Masui ; 57(8): 996-8, 2008 Aug.
Article in Japanese | MEDLINE | ID: mdl-18710008

ABSTRACT

We have experienced a patient complaining of the prolonged pain after left hepatectomy. The patient was a 53-year-old man. He underwent left hepatectomy for cholangiocellular carcinoma, and complained of prolonged abdominal pain for more than 10 days after the operation. After detailed examinations, we noticed duodenal perforation. After the conservative treatment, his pain was improved. In this case, the causes of the prolonged pain might be peritoneal irritation caused by gastric contents and duodenal perforation. The peritoneal irritation was caused by bile leakage and the deformity of the stomach that might be due to the enlarged dead space after left hepatectomy. We should be cautious of possible pyloric obstruction as the cause of prolonged pain after left hepatectomy.


Subject(s)
Duodenal Diseases/complications , Hepatectomy , Intestinal Perforation/complications , Pain, Intractable/etiology , Bile , Humans , Male , Middle Aged , Postoperative Complications
19.
Anesth Analg ; 104(2): 301-7, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17242084

ABSTRACT

Although it is widely used, the mechanisms and effects of acupuncture on pain are not completely understood. Recently, increased nitric oxide (NO) synthase activity has been found in meridians and acupoints. Because NO is a key regulator of local circulation, and because change in circulation can affect the development and persistence of pain, we propose that acupuncture might regulate NO levels. We studied the effects of acupuncture on local NO levels and circulation in a randomized, double-blind, crossover study with 20 volunteers, each of whom underwent one session each of real and noninvasive sham acupuncture in a single hand and forearm with a 1-wk interval between treatments. NO concentration in the plasma from the acupunctured arm was significantly increased by 2.8 +/- 1.5 micromol/L at 5 min and 2.5 +/- 1.4 micromol/L at 60 min after acupuncture. Blood flow in palmar subcutaneous tissue of the acupunctured arm also increased, and this correlated with the NO increase. These changes were not observed in noninvasive sham-acupunctured hands and forearms. In conclusion, acupuncture increases the NO level in treated regions and thereby increases local circulation. These regulatory effects might contribute to pain relief provided by acupuncture.


Subject(s)
Acupuncture Points , Acupuncture Therapy/methods , Forearm/blood supply , Hand/blood supply , Nitric Oxide/blood , Acupuncture Therapy/instrumentation , Adult , Cross-Over Studies , Double-Blind Method , Forearm/physiology , Hand/physiology , Humans , Regional Blood Flow/physiology
20.
Anesth Analg ; 104(5): 1136-44, tables of contents, 2007 May.
Article in English | MEDLINE | ID: mdl-17456664

ABSTRACT

BACKGROUND: Microglial cells play important roles in coordinating the inflammatory brain responses to hypoxia and trauma. Ionotropic P2X receptors and metabotropic P2Y receptors (P2YRs) expressed in microglia can be activated by extracellular adenosine triphosphate (ATP) derived from damaged cells or astrocytes, and participate in the signaling pathways evoked in brain insult. Although several inhaled and IV anesthetics produce neuroprotective effects through neuronal mechanisms, little is known about how general anesthetics modulate microglial responses in the pathological state. We examined the effects of various general anesthetics on purinergic responses in a rat microglial cell line. METHODS: Currents were consistently activated by applications of ATP via a U-tube system under the whole-cell configuration. ATP-induced nondesensitizing currents observed after several applications of ATP exhibited characteristics of P2X7 receptors. The P2YRs-mediated mobilization of intracellular Ca2+ was measured using a Ca2+-sensitive fluorescent dye (fura-2). RESULTS: Inhaled anesthetics (sevoflurane, isoflurane, and halothane) at doses three times as high as minimum alveolar concentrations had no effect on the P2X7Rs-mediated currents. IV anesthetics (ketamine, propofol, and thiopental) enhanced the P2X7Rs-mediated currents reversibly. The potencies for activation of P2X7Rs were not correlated with the octanol/buffer partition coefficients. Thiopental, at low concentrations, slightly inhibited the P2X7Rs-mediated currents, suggesting its dual actions on P2X7Rs. The P2YRs-mediated mobilization of intracellular Ca2+ was not affected by any of the general anesthetics tested. CONCLUSIONS: Our results suggest that IV anesthetics, particularly thiopental and propofol, may modulate microglial functions through P2X7Rs in pathological conditions.


Subject(s)
Anesthetics, General/pharmacology , Microglia/drug effects , Microglia/physiology , Receptors, Purinergic P2/physiology , Animals , Cell Line , Dose-Response Relationship, Drug , Rats , Receptors, Purinergic P2X7
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