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Sample records for volatile general anesthetics

  1. Shaker-Related Potassium Channels in the Central Medial Nucleus of the Thalamus Are Important Molecular Targets for Arousal Suppression by Volatile General Anesthetics

    Science.gov (United States)

    Birch, Alexandra M.; Tanaka, Brian S.; Sokolov, Yuri; Goldin, Alan L.; Chandy, K. George; Hall, James E.; Alkire, Michael T.

    2013-01-01

    The molecular targets and neural circuits that underlie general anesthesia are not fully elucidated. Here, we directly demonstrate that Kv1-family (Shaker-related) delayed rectifier K+ channels in the central medial thalamic nucleus (CMT) are important targets for volatile anesthetics. The modulation of Kv1 channels by volatiles is network specific as microinfusion of ShK, a potent inhibitor of Kv1.1, Kv1.3, and Kv1.6 channels, into the CMT awakened sevoflurane-anesthetized rodents. In heterologous expression systems, sevoflurane, isoflurane, and desflurane at subsurgical concentrations potentiated delayed rectifier Kv1 channels at low depolarizing potentials. In mouse thalamic brain slices, sevoflurane inhibited firing frequency and delayed the onset of action potentials in CMT neurons, and ShK-186, a Kv1.3-selective inhibitor, prevented these effects. Our findings demonstrate the exquisite sensitivity of delayed rectifier Kv1 channels to modulation by volatile anesthetics and highlight an arousal suppressing role of Kv1 channels in CMT neurons during the process of anesthesia. PMID:24107962

  2. CARDIOPROTECTION BY VOLATILE ANESTHETICS: FROM BENCH TO BEDSIDE AND BACK

    OpenAIRE

    Sedlić, Filip; Šepac, A; Muravyeva, M; Bošnjak, Željko

    2011-01-01

    Ischemia and reperfusion (I/R) injury of the heart can be ameliorated by volatile anesthetics (VAs). Application of VAs prior to the ischemic event triggers endogenous cardioprotective program that persists even after anesthetic removal, and it is called anesthetic-induced preconditioning (APC) (1). VAs can also reduce infarct size if applied during the reperfusion period (anesthetic postconditioning), where they can also exert protection by the direct effects on cardiac cel...

  3. Glutamatergic Neurotransmission Links Sensitivity to Volatile Anesthetics with Mitochondrial Function.

    Science.gov (United States)

    Zimin, Pavel I; Woods, Christian B; Quintana, Albert; Ramirez, Jan-Marino; Morgan, Philip G; Sedensky, Margaret M

    2016-08-22

    An enigma of modern medicine has persisted for over 150 years. The mechanisms by which volatile anesthetics (VAs) produce their effects (loss of consciousness, analgesia, amnesia, and immobility) remain an unsolved mystery. Many attractive putative molecular targets have failed to produce a significant effect when genetically tested in whole-animal models [1-3]. However, mitochondrial defects increase VA sensitivity in diverse organisms from nematodes to humans [4-6]. Ndufs4 knockout (KO) mice lack a subunit of mitochondrial complex I and are strikingly hypersensitive to VAs yet resistant to the intravenous anesthetic ketamine [7]. The change in VA sensitivity is the largest reported for a mammal. Limiting NDUFS4 loss to a subset of glutamatergic neurons recapitulates the VA hypersensitivity of Ndufs4(KO) mice, while loss in GABAergic or cholinergic neurons does not. Baseline electrophysiologic function of CA1 pyramidal neurons does not differ between Ndufs4(KO) and control mice. Isoflurane concentrations that anesthetize only Ndufs4(KO) mice (0.6%) decreased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) only in Ndufs4(KO) CA1 neurons, while concentrations effective in control mice (1.2%) decreased sEPSC frequencies in both control and Ndufs4(KO) CA1 pyramidal cells. Spontaneous inhibitory postsynaptic currents (sIPSCs) were not differentially affected between genotypes. The effects of isoflurane were similar on evoked field excitatory postsynaptic potentials (fEPSPs) and paired pulse facilitation (PPF) in KO and control hippocampal slices. We propose that CA1 presynaptic excitatory neurotransmission is hypersensitive to isoflurane in Ndufs4(KO) mice due to the inhibition of pre-existing reduced complex I function, reaching a critical reduction that can no longer meet metabolic demands.

  4. Goalpha regulates volatile anesthetic action in Caenorhabditis elegans.

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    van Swinderen, B; Metz, L B; Shebester, L D; Mendel, J E; Sternberg, P W; Crowder, C M

    2001-06-01

    To identify genes controlling volatile anesthetic (VA) action, we have screened through existing Caenorhabditis elegans mutants and found that strains with a reduction in Go signaling are VA resistant. Loss-of-function mutants of the gene goa-1, which codes for the alpha-subunit of Go, have EC(50)s for the VA isoflurane of 1.7- to 2.4-fold that of wild type. Strains overexpressing egl-10, which codes for an RGS protein negatively regulating goa-1, are also isoflurane resistant. However, sensitivity to halothane, a structurally distinct VA, is differentially affected by Go pathway mutants. The RGS overexpressing strains, a goa-1 missense mutant found to carry a novel mutation near the GTP-binding domain, and eat-16(rf) mutants, which suppress goa-1(gf) mutations, are all halothane resistant; goa-1(null) mutants have wild-type sensitivities. Double mutant strains carrying mutations in both goa-1 and unc-64, which codes for a neuronal syntaxin previously found to regulate VA sensitivity, show that the syntaxin mutant phenotypes depend in part on goa-1 expression. Pharmacological assays using the cholinesterase inhibitor aldicarb suggest that VAs and GOA-1 similarly downregulate cholinergic neurotransmitter release in C. elegans. Thus, the mechanism of action of VAs in C. elegans is regulated by Goalpha, and presynaptic Goalpha-effectors are candidate VA molecular targets.

  5. Inhibition of firefly luciferase by general anesthetics: effect on in vitro and in vivo bioluminescence imaging.

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    Marleen Keyaerts

    Full Text Available UNLABELLED: Bioluminescence imaging is routinely performed in anesthetized mice. Often isoflurane anesthesia is used because of its ease of use and fast induction/recovery. However, general anesthetics have been described as important inhibitors of the luciferase enzyme reaction. AIM: To investigate frequently used mouse anesthetics for their direct effect on the luciferase reaction, both in vitro and in vivo. MATERIALS AND METHODS: isoflurane, sevoflurane, desflurane, ketamine, xylazine, medetomidine, pentobarbital and avertin were tested in vitro on luciferase-expressing intact cells, and for non-volatile anesthetics on intact cells and cell lysates. In vivo, isoflurane was compared to unanesthetized animals and different anesthetics. Differences in maximal photon emission and time-to-peak photon emission were analyzed. RESULTS: All volatile anesthetics showed a clear inhibitory effect on the luciferase activity of 50% at physiological concentrations. Avertin had a stronger inhibitory effect of 80%. For ketamine and xylazine, increased photon emission was observed in intact cells, but this was not present in cell lysate assays, and was most likely due to cell toxicity and increased cell membrane permeability. In vivo, the highest signal intensities were measured in unanesthetized mice and pentobarbital anesthetized mice, followed by avertin. Isoflurane and ketamine/medetomidine anesthetized mice showed the lowest photon emission (40% of unanesthetized, with significantly longer time-to-peak than unanesthetized, pentobarbital or avertin-anesthetized mice. We conclude that, although strong inhibitory effects of anesthetics are present in vitro, their effect on in vivo BLI quantification is mainly due to their hemodynamic effects on mice and only to a lesser extent due to the direct inhibitory effect.

  6. Development of three Drosophila melanogaster strains with different sensitivity to volatile anesthetics

    Institute of Scientific and Technical Information of China (English)

    LIU Jin; HU Zhao-yang; YE Qi-quan; DAI Shuo-hua

    2009-01-01

    Background The mechanisms of action for volatile anesthetics remain unknown for centuries partly owing to the insufficient or ineffective research models. We designed this study to develop three strains derived from a wild-type Drosophila melanogaster with different sensitivities to volatile anesthetics, which may ultimately facilitate molecular and genetic studies of the mechanism involved.Methods Median effective doses (ED50) of sevoflurane in seven-day-old virgin female and male wild-type Drosophila melanogaster were determined. The sensitive males and females of percentile 6-10 were cultured for breeding sensitive offspring (S1). So did median ones of percentile 48-52 for breeding median offspring (M1), resistant ones of percentile 91-95 for breeding resistant offspring (R1). Process was repeated through 31 generations, in the 37th generation, S37,M37 and R37 were used to determine ED50 for enflurane, isoflurane, sevoflurane, desflurane, halothane, methoxyflurane,chloroform and trichloroethylene, then ED50 values were correlated with minimum alveolar concentration (MAC) values in human.Results From a wild-type Drosophila melanogaster we were able to breed three strains with high, median and low sevoflurane requirements. The ratio of sevoflurane requirements of three strains were 1.20:1.00:0.53 for females and 1.22:1.00:0.72 for males. Strains sensitive, median and resistant to sevoflurane were also sensitive, median and resistant to other volatile anesthetics. For eight anesthetics, ED50 values in three strains correlated directly with MAC values in human.Conclusions Three Drosophila me/anogaster strains with high, median and low sensitivity to volatile anesthetics, but with same hereditary background were developed. The ED50 are directly correlated with MAC in human for eight volatile anesthetics.

  7. Volatile anesthetic for the control of posthypoxic refractory myoclonic status

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    Vivek Rayadurg

    2016-01-01

    Full Text Available Posthypoxic myoclonus (Lance-Adams syndrome is characterized by myoclonus involving multiple muscle groups which is resistant to most conventional antiepileptic drugs. We present a case of hypoxic brain injury-induced myoclonic status epilepticus successfully controlled with isoflurane. The antimyoclonic effects of isoflurane are likely due to potentiation of inhibitory postsynaptic GABA A receptor-mediated currents and its effects on thalamocortical pathways. It is effective even when intravenous agents fail to control myoclonus. It may be a useful alternative to intravenous anesthetics as a third tier therapy in patients with refractory status myoclonus.

  8. Effect of general anesthetics on the developing brain

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    S Velayudha Reddy

    2012-01-01

    Full Text Available Studies on rodents and subhuman primates suggest that prolonged exposure to general anesthetics may induce widespread neuronal cell death and neurological sequelae; seriously questioning the safety of pediatric anesthesia. This review presents recent developments in this rapidly emerging field. There is mounting and convincing preclinical evidence in rodents and nonhuman primates that anesthetics in common clinical use are neurotoxic to the developing brain in vitro and cause long-term neurobehavioral abnormalities in vivo. Prior to the publication of animal data and after the publication of animal data, there are several human cohort studies that demonstrate the association of poor neurodevelopmental outcome in neonates, who underwent major surgery during their neonatal period. This review summarizes our present understanding of some of the key components responsible for anesthesia-induced neuroapoptosis and offers some of neuroprotective strategies that could be beneficial as adjunct therapy in preventing anesthesia-induced death of developing neurons in the neonates. A randomized literature search was carried out using search words apoptosis, general anesthetics, and developing brain from 1979 to 2011 for effects of general anesthetics on developing brain in PUBMED and relevant published literature reviewed. General anesthetics may produce neurotoxicity and enduring cognitive impairment in young and aged animals, but the issue has not been adequately studied in humans. It is premature to recommend a change clinical practice based on the present data.

  9. Volatile Anesthetics. Is a New Player Emerging in Critical Care Sedation?

    Science.gov (United States)

    Jerath, Angela; Parotto, Matteo; Wasowicz, Marcin; Ferguson, Niall D

    2016-06-01

    Volatile anesthetic agent use in the intensive care unit, aided by technological advances, has become more accessible to critical care physicians. With increasing concern over adverse patient consequences associated with our current sedation practice, there is growing interest to find non-benzodiazepine-based alternative sedatives. Research has demonstrated that volatile-based sedation may provide superior awakening and extubation times in comparison with current intravenous sedation agents (propofol and benzodiazepines). Volatile agents may possess important end-organ protective properties mediated via cytoprotective and antiinflammatory mechanisms. However, like all sedatives, volatile agents are capable of deeply sedating patients, which can have respiratory depressant effects and reduce patient mobility. This review seeks to critically appraise current volatile use in critical care medicine including current research, technical consideration of their use, contraindications, areas of controversy, and proposed future research topics.

  10. Volatile anesthetic action in a computational model of the thalamic reticular nucleus.

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    Gottschalk, Allan; Miotke, Sam A

    2009-05-01

    Although volatile anesthetics (VAs) modulate the activity of multiple ion channels, the process whereby one or more of these effects are integrated to produce components of the general anesthetic state remains enigmatic. Computer models offer the opportunity to examine systems level effects of VA action at one or more sites. Motivated by the role of the thalamus in consciousness and sensory processing, a computational model of the thalamic reticular nucleus was used to determine the collective impact on model behavior of VA action at multiple sites. A computational model of the thalamic reticular nucleus was modified to permit VA modulation of its ion channels. Isobolographic analysis was used to determine how multiple sites interact. VA modulation of either T-type Ca(2+) channels or gamma-aminobutyric acid type A receptors led to increased network synchrony. VA modulation of both further increased network synchronization. VA-induced decrements in Ca(2+) current permitted greater impact of inhibitory currents on membrane potential, but at higher VA concentrations the decrease in Ca(2+) current led to a decreased number of spikes in the burst generating the inhibitory signal. MAC-awake (the minimum alveolar concentration at which 50% of subjects will recover consciousness) concentrations of both isoflurane and halothane led to similar levels of network synchrony in the model. Relatively modest VA effects at both T-type Ca(2+) channels and gamma-aminobutyric acid type A receptors can substantially alter network behavior in a computational model of a thalamic nucleus. The similarity of network behavior at MAC-awake concentrations of different VAs is consistent with a contribution of the thalamus to VA-induced unconsciousness through action at these channels.

  11. Liquid general anesthetics lower critical temperatures in plasma membrane vesicles

    CERN Document Server

    Gray, Ellyn; Machta, Benjamin B; Veatch, Sarah L

    2013-01-01

    A large and diverse array of small hydrophobic molecules induce general anesthesia. Their efficacy as anesthetics has been shown to correlate both with their affinity for a hydrophobic environment and with their potency in inhibiting certain ligand gated ion channels. Here we explore the effects that n-alcohols and other liquid anesthetics have on the two-dimensional miscibility critical point observed in cell derived giant plasma membrane vesicles (GPMVs). We show that anesthetics depress the critical temperature (Tc) of these GPMVs without strongly altering the ratio of the two liquid phases found below Tc. The magnitude of this affect is consistent across n-alcohols when their concentration is rescaled by the median anesthetic concentration (AC50) for tadpole anesthesia, but not when plotted against the overall concentration in solution. At AC50 we see a 4{\\deg}C downward shift in Tc, much larger than is typically seen in the main chain transition at these anesthetic concentrations. GPMV miscibility critic...

  12. Volatile anesthetics inhibit the activity of calmodulin by interacting with its hydrophobic site

    Institute of Scientific and Technical Information of China (English)

    ZHOU Miao-miao; XIA Hui-min; LIU Jiao; XU You-nian; XIN Nai-xin; ZHANG Shi-hai

    2012-01-01

    Background Volatile anesthetics (VAs) may affect varied and complex physiology processes by manipulating Ca2+-calmodulin (CaM).However,the detailed mechanism about the action of VAs on CaM has not been elucidated.This study was undertaken to examine the effects of VAs on the conformational change,hydrophobic site,and downstream signaling pathway of CaM,to explore the possible mechanism of anesthetic action of VAs.Methods Real-time second-harmonic generation (SHG) was performed to monitor the conformational change of CaM in the presence of VAs, each plus 100 μmol/L Ca2+. A hydrophobic fluorescence indicator,8-anilinonaphthalene-1-sulfonate (ANS),was utilized to define whether the VAs would interact with CaM at the hydrophobic site or not.High-performance liquid chromatography (HPLC) was carried out to analyze the activity of CaM-dependent phosphodiesterase (PDE1) in the presence of VAs.The VAs studied were ether,enflurane,isoflurane,and sevoflurane,with their aqueous concentrations 7.6,9.5,11.4 mmol/L; 0.42,0.52,0.62 mmol/L; 0.25,0.31,0.37 mmol/L and 0.47,0.59,0.71 mmol/L respectively,each were equivalent to their 0.8,1.0 and 1.2 concentration for 50% of maximal effect (EC50) for general anesthesia.Results The second-harmonic radiation of CaM in the presence of Ca2+ was largely inhibited by the VAs.The fluorescence intensity of ANS,generated by binding of Ca2+ to CaM,was reversed by the VAs.HPLC results also showed that AMP,the product of the hydrolysis of cAMP by CaM-dependent PDE1,was reduced by the VAs.Conclusions Our findings demonstrate that the above VAs interact with the hydrophobic core of Ca2+-CaM and the interaction results in the inhibition of the conformational change and activity of CaM.This in vitro study may provide us insight into the possible mechanism of anesthetic action of VAs in vivo.

  13. Volatile Anesthetics Influence Blood-Brain Barrier Integrity by Modulation of Tight Junction Protein Expression in Traumatic Brain Injury

    OpenAIRE

    Thal, Serge C.; Clara Luh; Eva-Verena Schaible; Ralph Timaru-Kast; Jana Hedrich; Luhmann, Heiko J.; Kristin Engelhard; Zehendner, Christoph M.

    2012-01-01

    Disruption of the blood-brain barrier (BBB) results in cerebral edema formation, which is a major cause for high mortalityrnafter traumatic brain injury (TBI). As anesthetic care is mandatory in patients suffering from severe TBI it may be importantrnto elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ) such as zonularnoccludens-1 (ZO-1) and claudin-5 (cl5) play a central role for BBB stability. First, the influence of the volatile anesthet...

  14. Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis?

    LENUS (Irish Health Repository)

    Goto, Y

    2012-02-03

    PURPOSE: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents. METHODS: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n = 20) and unexposed volunteers (n = 10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out. RESULTS: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers [50.5 (9.7)%; P = 0.008] than in unexposed volunteers [57.3 (5.1)%]. CONCLUSION: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.

  15. Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongmin; Astrof, Nathan S.; Liu, Jin-Huan; Wang, Jia-huai; Shimaoka, Motomu; (Harvard-Med); (DFCI)

    2009-09-15

    Volatile anesthetics (VAs), such as isoflurane, induce a general anesthetic state by binding to specific targets (i.e., ion channels) in the central nervous system (CNS). Simultaneously, VAs modulate immune functions, possibly via direct interaction with alternative targets on leukocytes. One such target, the integrin lymphocyte function-associated antigen-1 (LFA-1), has been shown previously to be inhibited by isoflurane. A better understanding of the mechanism by which isoflurane alters protein function requires the detailed information about the drug-protein interaction at an atomic level. Here, we describe the crystal structure of the LFA-1 ligand-binding domain (I domain) in complex with isoflurane at 1.6 {angstrom}. We discovered that isoflurane binds to an allosteric cavity previously implicated as critical for the transition of LFA-1 from the low- to the high-affinity state. The isoflurane binding site in the I domain involves an array of amphiphilic interactions, thereby resembling a 'common anesthetic binding motif' previously predicted for authentic VA binding sites. These results suggest that the allosteric modulation of protein function by isoflurane, as demonstrated for the integrin LFA-1, might represent a unified mechanism shared by the interactions of volatile anesthetics with targets in the CNS. Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems.

  16. Relationship between pre-anesthetic and intra-anesthetic airway resistance in patients undergoing general anesthesia: A prospective observational study

    Science.gov (United States)

    Ikeda, Takamitsu; Uchida, Kanji; Yamauchi, Yasuhiro; Nagase, Takahide; Oba, Koji; Yamada, Yoshitsugu

    2017-01-01

    Surgery patients in Japan undergo routine spirometry testing prior to general anesthesia. The use of a flow sensor during general anesthesia has recently become common. However, it is not certain whether the information derived from flow-volume curves is being adequately used for mechanical ventilation management during general anesthesia. So far, there have been no attempts to calculate airway resistance using flow-volume curves. Therefore, we performed a prospective, observational study to investigate the relationship between pre-anesthetic and intra-anesthetic airway resistance in patients scheduled for surgery under general anesthesia. We calculated pre-anesthetic and intra-anesthetic airway resistance in each patient, based on the slopes of flow-volume curves obtained prior to and during general anesthesia. We also calculated endotracheal tube resistance to correct the intra-anesthetic airway resistance values calculated. A total of 526 patients were included in the study, and 98 patients had a forced expiratory volume in the first second/forced vital capacity ratio of mechanical ventilation (p = 0.48). Pre-anesthetic and intra-anesthetic airway resistance values were closer to each other in patients without airflow obstruction, with a mean difference < 1.0 cmH2O L-1s-1, than in those with airflow obstruction, although these respiratory parameters were significantly different (p < 0.001). Intra-anesthetic airway resistance was not related to the FEV1/FVC ratio, regardless of the degree to which the FEV1/FVC ratio reflected pre-anesthetic airway resistance. As compared with patients with airflow obstruction, the mean difference between pre-anesthetic and intra-anesthetic airway resistance was small in patients without airflow obstruction. PMID:28212451

  17. Volatile anesthetics influence blood-brain barrier integrity by modulation of tight junction protein expression in traumatic brain injury.

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    Serge C Thal

    Full Text Available Disruption of the blood-brain barrier (BBB results in cerebral edema formation, which is a major cause for high mortality after traumatic brain injury (TBI. As anesthetic care is mandatory in patients suffering from severe TBI it may be important to elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ such as zonula occludens-1 (ZO-1 and claudin-5 (cl5 play a central role for BBB stability. First, the influence of the volatile anesthetics sevoflurane and isoflurane on in-vitro BBB integrity was investigated by quantification of the electrical resistance (TEER in murine brain endothelial monolayers and neurovascular co-cultures of the BBB. Secondly brain edema and TJ expression of ZO-1 and cl5 were measured in-vivo after exposure towards volatile anesthetics in native mice and after controlled cortical impact (CCI. In in-vitro endothelial monocultures, both anesthetics significantly reduced TEER within 24 hours after exposure. In BBB co-cultures mimicking the neurovascular unit (NVU volatile anesthetics had no impact on TEER. In healthy mice, anesthesia did not influence brain water content and TJ expression, while 24 hours after CCI brain water content increased significantly stronger with isoflurane compared to sevoflurane. In line with the brain edema data, ZO-1 expression was significantly higher in sevoflurane compared to isoflurane exposed CCI animals. Immunohistochemical analyses revealed disruption of ZO-1 at the cerebrovascular level, while cl5 was less affected in the pericontusional area. The study demonstrates that anesthetics influence brain edema formation after experimental TBI. This effect may be attributed to modulation of BBB permeability by differential TJ protein expression. Therefore, selection of anesthetics may influence the barrier function and introduce a strong bias in experimental research on pathophysiology of BBB dysfunction. Future research is required to investigate

  18. Comparison of pneumotachography and anemometery for flow measurement during mechanical ventilation with volatile anesthetics.

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    Mondoñedo, Jarred R; Herrmann, Jacob; McNeil, John S; Kaczka, David W

    2016-11-14

    Volatile anesthetics alter the physical properties of inhaled gases, such as density and viscosity. We hypothesized that the use of these agents during mechanical ventilation would yield systematic biases in estimates of flow ([Formula: see text]) and tidal volume (V T) for two commonly used flowmeters: the pneumotachograph (PNT), which measures a differential pressure across a calibrated resistive element, and the hot-wire anemometer (HWA), which operates based on convective heat transfer from a current-carrying wire to a flowing gas. We measured [Formula: see text] during ventilation of a spring-loaded mechanical test lung, using both the PNT and HWA placed in series at the airway opening. Delivered V T was estimated from the numerically-integrated [Formula: see text]. Measurements were acquired under baseline conditions with room air, and during ventilation with increasing concentrations of isoflurane, sevoflurane, and desflurane. We also evaluated a simple compensation technique for HWA flow, which accounted for changes in gas mixture density. We found that discrepancies in estimated V T between the PNT and HWA occurred during ventilation with isoflurane (6.3 ± 3.0%), sevoflurane (10.0 ± 7.3%), and desflurane (25.8 ± 17.2%) compared to baseline conditions. The magnitude of these discrepancies increased with anesthetic concentration. A simple compensation factor based on density reduced observed differences between the flowmeters, regardless of the anesthetic or concentration. These data indicate that the choice and concentration of anesthetic agents are primary factors for differences in estimated V T between the PNT and HWA. Such discrepancies may be compensated by accounting for alterations in gas density.

  19. Neurotoxicity of general anesthetics: A modern view of the problem

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    A. M. Ovezov

    2015-01-01

    Full Text Available All general anesthetics routinely used in clinical practice are noted to have a neurotoxic effect on the brain in different animal species including primates. The negative effects observed both in young and sexually mature animals include apoptotic neuronal cell death, suppression of neurogenesis and gliogenesis, neuroinflammation, as well as learning and memory impairments. A number of epidemiologic surveys have established an association between anesthesia in patients younger than 3 to 4 years and subsequent learning disabilities and language disorders whereas others have not found this link. In middle-aged and elderly patients, anesthesia is frequently associated with the development of postoperative cognitive dysfunction. The key component of its pathogenesis (general anesthesia itself or other factors, such as operative injury, an inflammatory response, pain syndrome, intraoperative complications, underlying disease in a patient remains unelucidated. It is concluded that there is a need for additional experimental and clinical studies of the pathogenesis of these undesirable phenomena to be prevented and corrected.

  20. Strychnine-sensitive glycine receptors mediate the analgesic but not hypnotic effects of emulsified volatile anesthetics.

    Science.gov (United States)

    Chen, Yan; Dai, Ti-Jun; Zeng, Yin-Ming

    2007-01-01

    The present study was designed to investigate the role of strychnine-sensitive glycine receptors in hypnosis and analgesia induced by emulsified volatile anesthetics. After having established the mice model of hypnosis and analgesia by intraperitoneally injecting (i.p.) appropriate doses of ether, enflurane, isoflurane or sevoflurane, we intracerebroventricularly (i.c.v.) or intrathecally (i.t.) injected different doses of strychnine and then observed the effects on the sleeping time using the awaken test and the pain index in hot-plate test (HPPI) using the hot-plate test. In the awaken test, strychnine 1, 2, 4 microg (i.c.v.) had no distinctive effect on the sleeping time of the mice treated with the four emulsified inhalation anesthetics mentioned above (p > 0.05); in the hot-plate test, strychnine 0.1, 0.2, 0.4 microg (i.t.) can significantly and dose-dependently decrease the HPPI of the mice treated with emulsified ether, enflurane and sevoflurane (p strychnine 0.1 microg (i.t.) did not affect the HPPI of the mice treated with emulsified isoflurane (p > 0.05), but 0.2 and 0.4 microg (i.t.) can significantly decrease the HPPI of the mice treatedwith emulsified isoflurane (p strychnine-sensitive glycine receptors may contribute to the analgesic but not to the hypnotic effects induced by ether, enflurane, isoflurane and sevoflurane. Copyright (c) 2007 S. Karger AG, Basel.

  1. Paired assessment of volatile anesthetic concentrations with synaptic actions recorded in vitro.

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    Stuart J McDougall

    Full Text Available The volatile anesthetic isoflurane poses a number of experimental challenges in the laboratory. Due to its rapid evaporation, the open conditions of most in vitro electrophysiological recording systems make the determination of actual isoflurane concentrations a challenge. Since the absolute anesthetic concentration in solution is directly related to efficacy, concentration measurements are important to allow comparisons between laboratory and clinical studies. In this study we quantify the sources of isoflurane loss during experimentation and describe a method for the measurement of isoflurane concentrations using gas chromatography and mass spectrometry simultaneous to in vitro electrophysiological measurements. Serial samples of perfused bath solution allowed correlation of isoflurane concentrations with ongoing biological effects. Saturated physiological solutions contained 13.4 +/- 0.2 mM isoflurane and were diluted to desired "nominal" concentrations for experiments. The perfusion system established stable isoflurane concentrations within the bath by 2 minutes. However, bath isoflurane concentrations varied substantially and unpredictably between experiments. The magnitudes of such discrepancies in isoflurane concentrations spanned clinically important levels. Our studies suggest that, despite countermeasures, solution handling significantly impacted the isoflurane content in the tissue bath. The magnitude of these discrepancies appears to necessitate systematic direct measurement of bath isoflurane concentrations during most in vitro conditions.

  2. Assessing the impact on global climate from general anesthetic gases

    DEFF Research Database (Denmark)

    Andersen, Mads P. Sulbæk; Nielsen, Ole John; Wallington, Timothy J.

    2012-01-01

    Although present in the atmosphere with a combined concentration approximately 100,000 times lower than carbon dioxide (i.e., the principal anthropogenic driver of climate change), halogenated organic compounds are responsible for a warming effect of approximately 10% to 15% of the total...... regarding the impact of anesthetic gas release on the environment, with particular focus on its contribution to the radiative forcing of climate change....... anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750). The family of anesthetic gases includes several halogenated organic compounds that are strong greenhouse gases. In this short report, we provide an overview of the state of knowledge...

  3. Latency of auditory evoked potential monitoring the effects of general anesthetics on nerve fibers and synapses

    OpenAIRE

    Bowan Huang; Feixue Liang; Lei Zhong; Minlin Lin; Juan Yang; Linqing Yan; Jinfan Xiao; Zhongju Xiao

    2015-01-01

    Auditory evoked potential (AEP) is an effective index for the effects of general anesthetics. However, it’s unknown if AEP can differentiate the effects of general anesthetics on nerve fibers and synapses. Presently, we investigated AEP latency and amplitude changes to different acoustic intensities during pentobarbital anesthesia. Latency more regularly changed than amplitude during anesthesia. AEP Latency monotonically decreased with acoustic intensity increase (i.e., latency-intensity curv...

  4. Design, Synthesis, and Evaluation of Novel 2,6-Disubstituted Phenol Derivatives as General Anesthetics.

    Science.gov (United States)

    Qin, Linlin; Ren, Lei; Wan, Songlin; Liu, Guoliang; Luo, Xinfeng; Liu, Zhenhong; Li, Fangqiong; Yu, Yan; Liu, Jianyu; Wei, Yonggang

    2017-05-11

    A novel series of optically active 2,6-disubstituted alkylphenols with improved anesthetic profiles compared to widely used propofol were synthesized. The incorporation of the cyclopropyl group not only increased the steric effect but also introduced stereoselective effects over their anesthetic properties. Compounds 1, 2, and 6 were selected as potential candidates for further preclinical development including studies of their water-soluble prodrugs. Clinical studies of candidate compound 6 (Haisco HSK3486) as a general anesthetic are being performed in Australia and China.

  5. Bottom-Up and Top-Down Mechanisms of General Anesthetics Modulate Different Dimensions of Consciousness.

    Science.gov (United States)

    Mashour, George A; Hudetz, Anthony G

    2017-01-01

    There has been controversy regarding the precise mechanisms of anesthetic-induced unconsciousness, with two salient approaches that have emerged within systems neuroscience. One prominent approach is the "bottom up" paradigm, which argues that anesthetics suppress consciousness by modulating sleep-wake nuclei and neural circuits in the brainstem and diencephalon that have evolved to control arousal states. Another approach is the "top-down" paradigm, which argues that anesthetics suppress consciousness by modulating the cortical and thalamocortical circuits involved in the integration of neural information. In this article, we synthesize these approaches by mapping bottom-up and top-down mechanisms of general anesthetics to two distinct but inter-related dimensions of consciousness: level and content. We show how this explains certain empirical observations regarding the diversity of anesthetic drug effects. We conclude with a more nuanced discussion of how levels and contents of consciousness interact to generate subjective experience and what this implies for the mechanisms of anesthetic-induced unconsciousness.

  6. Bottom-Up and Top-Down Mechanisms of General Anesthetics Modulate Different Dimensions of Consciousness

    Science.gov (United States)

    Mashour, George A.; Hudetz, Anthony G.

    2017-01-01

    There has been controversy regarding the precise mechanisms of anesthetic-induced unconsciousness, with two salient approaches that have emerged within systems neuroscience. One prominent approach is the “bottom up” paradigm, which argues that anesthetics suppress consciousness by modulating sleep-wake nuclei and neural circuits in the brainstem and diencephalon that have evolved to control arousal states. Another approach is the “top-down” paradigm, which argues that anesthetics suppress consciousness by modulating the cortical and thalamocortical circuits involved in the integration of neural information. In this article, we synthesize these approaches by mapping bottom-up and top-down mechanisms of general anesthetics to two distinct but inter-related dimensions of consciousness: level and content. We show how this explains certain empirical observations regarding the diversity of anesthetic drug effects. We conclude with a more nuanced discussion of how levels and contents of consciousness interact to generate subjective experience and what this implies for the mechanisms of anesthetic-induced unconsciousness. PMID:28676745

  7. Early exposure to volatile anesthetics impairs long-term associative learning and recognition memory.

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    Bradley H Lee

    Full Text Available BACKGROUND: Anesthetic exposure early in life affects neural development and long-term cognitive function, but our understanding of the types of memory that are altered is incomplete. Specific cognitive tests in rodents that isolate different memory processes provide a useful approach for gaining insight into this issue. METHODS: Postnatal day 7 (P7 rats were exposed to either desflurane or isoflurane at 1 Minimum Alveolar Concentration for 4 h. Acute neuronal death was assessed 12 h later in the thalamus, CA1-3 regions of hippocampus, and dentate gyrus. In separate behavioral experiments, beginning at P48, subjects were evaluated in a series of object recognition tests relying on associative learning, as well as social recognition. RESULTS: Exposure to either anesthetic led to a significant increase in neuroapoptosis in each brain region. The extent of neuronal death did not differ between groups. Subjects were unaffected in simple tasks of novel object and object-location recognition. However, anesthetized animals from both groups were impaired in allocentric object-location memory and a more complex task requiring subjects to associate an object with its location and contextual setting. Isoflurane exposure led to additional impairment in object-context association and social memory. CONCLUSION: Isoflurane and desflurane exposure during development result in deficits in tasks relying on associative learning and recognition memory. Isoflurane may potentially cause worse impairment than desflurane.

  8. Effect of four-alpha-helix bundle cavity size on volatile anesthetic binding energetics.

    Science.gov (United States)

    Manderson, Gavin A; Michalsky, Stuart J; Johansson, Jonas S

    2003-09-30

    Currently, it is thought that inhalational anesthetics cause anesthesia by binding to ligand-gated ion channels. This is being investigated using four-alpha-helix bundles, small water-soluble analogues of the transmembrane domains of the "natural" receptor proteins. The study presented here specifically investigates how multiple alanine-to-valine substitutions (which each decrease the volume of the internal binding cavity by 38 A(3)) affect structure, stability, and anesthetic binding affinity of the four-alpha-helix bundles. Structure remains essentially unchanged when up to four alanine residues are changed to valine. However, stability increases as the number of these substitutions is increased. Anesthetic binding affinities are also affected. Halothane binds to the four-alpha-helix bundle variants with 0, 1, and 2 substitutions with equivalent affinities but binds to the variants with 3 and 4 more tightly. The same order of binding affinities was observed for chloroform, although for a particular variant, chloroform was bound less tightly. The observed differences in binding affinities may be explained in terms of a modulation of van der Waals and hydrophobic interactions between ligand and receptor. These, in turn, could result from increased four-alpha-helix bundle binding cavity hydrophobicity, a decrease in cavity size, or improved ligand/receptor shape complementarity.

  9. A high-throughput approach for identification of novel general anesthetics.

    Science.gov (United States)

    Lea, Wendy A; Xi, Jin; Jadhav, Ajit; Lu, Louis; Austin, Christopher P; Simeonov, Anton; Eckenhoff, Roderic G

    2009-09-24

    Anesthetic development has been a largely empirical process. Recently, we described a GABAergic mimetic model system for anesthetic binding, based on apoferritin and an environment-sensitive fluorescent probe. Here, a competition assay based on 1-aminoanthracene and apoferritin has been taken to a high throughput screening level, and validated using the LOPAC(1280) library of drug-like compounds. A raw hit rate of approximately 15% was reduced through the use of computational filters to yield an overall hit rate of approximately 1%. These hits were validated using isothermal titration calorimetry. The success of this initial screen and computational triage provides feasibility to undergo a large scale campaign to discover novel general anesthetics.

  10. A high-throughput approach for identification of novel general anesthetics.

    Directory of Open Access Journals (Sweden)

    Wendy A Lea

    Full Text Available Anesthetic development has been a largely empirical process. Recently, we described a GABAergic mimetic model system for anesthetic binding, based on apoferritin and an environment-sensitive fluorescent probe. Here, a competition assay based on 1-aminoanthracene and apoferritin has been taken to a high throughput screening level, and validated using the LOPAC(1280 library of drug-like compounds. A raw hit rate of approximately 15% was reduced through the use of computational filters to yield an overall hit rate of approximately 1%. These hits were validated using isothermal titration calorimetry. The success of this initial screen and computational triage provides feasibility to undergo a large scale campaign to discover novel general anesthetics.

  11. General anesthetics have differential inhibitory effects on gap junction channels and hemichannels in astrocytes and neurons.

    Science.gov (United States)

    Liu, Xinhe; Gangoso, Ester; Yi, Chenju; Jeanson, Tiffany; Kandelman, Stanislas; Mantz, Jean; Giaume, Christian

    2016-04-01

    Astrocytes represent a major non-neuronal cell population actively involved in brain functions and pathologies. They express a large amount of gap junction proteins that allow communication between adjacent glial cells and the formation of glial networks. In addition, these membrane proteins can also operate as hemichannels, through which "gliotransmitters" are released, and thus contribute to neuroglial interaction. There are now reports demonstrating that alterations of astroglial gap junction communication and/or hemichannel activity impact neuronal and synaptic activity. Two decades ago we reported that several general anesthetics inhibited gap junctions in primary cultures of astrocytes (Mantz et al., (1993) Anesthesiology 78(5):892-901). As there are increasing studies investigating neuroglial interactions in anesthetized mice, we here updated this previous study by employing acute cortical slices and by characterizing the effects of general anesthetics on both astroglial gap junctions and hemichannels. As hemichannel activity is not detected in cortical astrocytes under basal conditions, we treated acute slices with the endotoxin LPS or proinflammatory cytokines to induce hemichannel activity in astrocytes, which in turn activated neuronal hemichannels. We studied two extensively used anesthetics, propofol and ketamine, and the more recently developed dexmedetomidine. We report that these drugs have differential inhibitory effects on gap junctional communication and hemichannel activity in astrocytes when used in their respective, clinically relevant concentrations, and that dexmedetomidine appears to be the least effective on both channel functions. In addition, the three anesthetics have similar effects on neuronal hemichannels. Altogether, our observations may contribute to optimizing the selection of anesthetics for in vivo animal studies.

  12. Allyl m-Trifluoromethyldiazirine Mephobarbital: An Unusually Potent Enantioselective and Photoreactive Barbiturate General Anesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Savechenkov, Pavel Y.; Zhang, Xi; Chiara, David C.; Stewart, Deirdre S.; Ge, Rile; Zhou, Xiaojuan; Raines, Douglas E.; Cohen, Jonathan B.; Forman, Stuart A.; Miller, Keith W.; Bruzik, Karol S. (Harvard-Med); (Mass. Gen. Hosp.); (UIC)

    2012-12-10

    We synthesized 5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (14), a trifluoromethyldiazirine-containing derivative of general anesthetic mephobarbital, separated the racemic mixture into enantiomers by chiral chromatography, and determined the configuration of the (+)-enantiomer as S by X-ray crystallography. Additionally, we obtained the {sup 3}H-labeled ligand with high specific radioactivity. R-(-)-14 is an order of magnitude more potent than the most potent clinically used barbiturate, thiopental, and its general anesthetic EC{sub 50} approaches those for propofol and etomidate, whereas S-(+)-14 is 10-fold less potent. Furthermore, at concentrations close to its anesthetic potency, R-(-)-14 both potentiated GABA-induced currents and increased the affinity for the agonist muscimol in human {alpha}1{beta}2/3{gamma}2L GABA{sub A} receptors. Finally, R-(-)-14 was found to be an exceptionally efficient photolabeling reagent, incorporating into both {alpha}1 and {beta}3 subunits of human {alpha}1{beta}3 GABAA receptors. These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors.

  13. CT chest under general anesthesia: pulmonary, anesthetic and radiologic dilemmas

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Mohamed [Cincinnati Children' s Hospital Medical Center, Department of Anesthesiology, Cincinnati, OH (United States); Towe, Christopher [Cincinnati Children' s Hospital Medical Center, Department of Pulmonary Medicine, Cincinnati, OH (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2015-07-15

    Today's practice of medicine involves ever more complex patients whose care is coordinated with multidisciplinary teams. Caring for these patients can challenge all members of the health care team. Sedation/anesthesia in infants/toddlers as well as uncooperative or intellectually or emotionally impaired children who require imaging studies of the chest are ongoing challenges. High-quality computed tomography (CT) chest imaging studies in children under general anesthesia are extremely important for accurate interpretation and subsequent medical decision-making. Anesthesia-induced atelectasis may obscure or mimic true pathology creating a significant quality issue. Obtaining a high-quality, motion-free chest imaging study in infants and children under general anesthesia remains a difficult task in many institutions. Meticulous attention to anesthesia and imaging techniques and specialized knowledge are required to properly perform and interpret chest imaging studies. In this commentary, we discuss the continuous struggle to obtain high-quality CT chest imaging under general anesthesia. We will also discuss the major concerns of the anesthesiologist, radiologist and pulmonologist and why cooperation and coordination among these providers are critical for an optimal quality study.

  14. General anesthetics inhibit LPS-induced IL-1β expression in glial cells.

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    Tomoharu Tanaka

    Full Text Available BACKGROUND: Glial cells, including microglia and astrocytes, are considered the primary source of proinflammatory cytokines in the brain. Immune insults stimulate glial cells to secrete proinflammatory cytokines that modulate the acute systemic response, which includes fever, behavioral changes, and hypothalamic-pituitary-adrenal (HPA axis activation. We investigated the effect of general anesthetics on proinflammatory cytokine expression in the primary cultured glial cells, the microglial cell line BV-2, the astrocytic cell line A-1 and mouse brain. METHODOLOGY/PRINCIPAL FINDINGS: Primary cultured glial cells were exposed to lipopolysaccharide (LPS in combination with general anesthetics including isoflurane, pentobarbital, midazolam, ketamine, and propofol. Following this treatment, we examined glial cell expression of the proinflammatory cytokines interleukin (IL-1β, IL-6, and tumor necrosis factor-alpha (TNF-α. LPS-induced expression of IL-1β mRNA and protein were significantly reduced by all the anesthetics tested, whereas IL-6 and TNF-α mRNA expression was unaffected. The anesthetics suppressed LPS-induced extracellular signal-regulated kinase 1/2 (ERK 1/2 phosphorylation, but did not affect nuclear factor-kappaB and activator protein-1 activation. The same effect was observed with BV-2, but not with A-1 cells. In the mouse experiments, LPS was injected intraperitoneally, and isoflurane suppressed IL-1β in the brain and adrenocorticotropic hormone in plasma, but not IL-1β in plasma. CONCLUSIONS/SIGNIFICANCE: Taken together, our results indicate that general anesthetics inhibit LPS-induced IL-1β upregulation in glial cells, particularly microglia, and affects HPA axis participation in the stress response.

  15. General anesthetics inhibit erythropoietin induction under hypoxic conditions in the mouse brain.

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    Tomoharu Tanaka

    Full Text Available BACKGROUND: Erythropoietin (EPO, originally identified as a hematopoietic growth factor produced in the kidney and fetal liver, is also endogenously expressed in the central nervous system (CNS. EPO in the CNS, mainly produced in astrocytes, is induced under hypoxic conditions in a hypoxia-inducible factor (HIF-dependent manner and plays a dominant role in neuroprotection and neurogenesis. We investigated the effect of general anesthetics on EPO expression in the mouse brain and primary cultured astrocytes. METHODOLOGY/PRINCIPAL FINDINGS: BALB/c mice were exposed to 10% oxygen with isoflurane at various concentrations (0.10-1.0%. Expression of EPO mRNA in the brain was studied, and the effects of sevoflurane, halothane, nitrous oxide, pentobarbital, ketamine, and propofol were investigated. In addition, expression of HIF-2α protein was studied by immunoblotting. Hypoxia-induced EPO mRNA expression in the brain was significantly suppressed by isoflurane in a concentration-dependent manner. A similar effect was confirmed for all other general anesthetics. Hypoxia-inducible expression of HIF-2α protein was also significantly suppressed with isoflurane. In the experiments using primary cultured astrocytes, isoflurane, pentobarbital, and ketamine suppressed hypoxia-inducible expression of HIF-2α protein and EPO mRNA. CONCLUSIONS/SIGNIFICANCE: Taken together, our results indicate that general anesthetics suppress activation of HIF-2 and inhibit hypoxia-induced EPO upregulation in the mouse brain through a direct effect on astrocytes.

  16. Anesthetic management of comprehensive dental restoration in a child with glutaric aciduria type 1 using volatile sevoflurane.

    Science.gov (United States)

    Teng, Wei-Nung; Lin, Su-Man; Niu, Dau-Ming; Kuo, Yi-Min; Chan, Kwok-Hon; Sung, Chun-Sung

    2014-10-01

    Glutaric aciduria type 1 (GA1) is a rare, inherited mitochondrial disorder that results from deficiency of mitochondrial glutaryl-CoA dehydrogenase. Most patients develop neurological dysfunction early in life, which leads to severe disabilities. We present a 37-month-old girl with GA1 manifested as macrocephaly and hypotonia who received comprehensive dental restoration surgery under general anesthesia with sevoflurane. She was placed on specialized fluid management during a preoperative fasting period and anesthesia was administered without complications. All the physiological parameters, including glucose and lactate blood levels and arterial blood gas were carefully monitored and maintained within normal range perioperatively. Strategies for anesthetic management should include prevention of pulmonary aspiration, dehydration, hyperthermia and catabolic state, adequate analgesia to minimize surgical stress, and avoidance of prolonged neuromuscular blockade. We administered general anesthesia with sevoflurane uneventfully, which was well tolerated by our patient with GA1. Additionally, communication with a pediatric geneticist and surgeons should be undertaken to formulate a comprehensive anesthetic strategy in these patients.

  17. General anesthetic conditions induce network synchrony and disrupt sensory processing in the cortex

    Directory of Open Access Journals (Sweden)

    Thomas eLissek

    2016-04-01

    Full Text Available General anesthetics are commonly used in animal models to study how sensory signals are represented in the brain. Here, we used two-photon (2P calcium activity imaging with cellular resolution to investigate how neuronal activity in layer 2/3 of the mouse barrel cortex is modified under the influence of different concentrations of chemically distinct general anesthetics. Our results show that a high isoflurane dose induces synchrony in local neuronal networks and these cortical activity patterns closely resemble those observed in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also induced similar activity patterns. While investigating the effects of deep isoflurane anesthesia on whisker and auditory evoked responses in the barrel cortex, we found that dedicated spatial regions for sensory signal processing become disrupted. We propose that our isoflurane-2P imaging paradigm can serve as an attractive model system to dissect cellular and molecular mechanisms that induce the anesthetic state, and it might also provide important insight into sleep-like brain states and consciousness.

  18. General Anesthetic Conditions Induce Network Synchrony and Disrupt Sensory Processing in the Cortex.

    Science.gov (United States)

    Lissek, Thomas; Obenhaus, Horst A; Ditzel, Désirée A W; Nagai, Takeharu; Miyawaki, Atsushi; Sprengel, Rolf; Hasan, Mazahir T

    2016-01-01

    General anesthetics are commonly used in animal models to study how sensory signals are represented in the brain. Here, we used two-photon (2P) calcium activity imaging with cellular resolution to investigate how neuronal activity in layer 2/3 of the mouse barrel cortex is modified under the influence of different concentrations of chemically distinct general anesthetics. Our results show that a high isoflurane dose induces synchrony in local neuronal networks and these cortical activity patterns closely resemble those observed in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also induced similar activity patterns. While investigating the effects of deep isoflurane anesthesia on whisker and auditory evoked responses in the barrel cortex, we found that dedicated spatial regions for sensory signal processing become disrupted. We propose that our isoflurane-2P imaging paradigm can serve as an attractive model system to dissect cellular and molecular mechanisms that induce the anesthetic state, and it might also provide important insight into sleep-like brain states and consciousness.

  19. Methemoglobin levels in generally anesthetized pediatric dental patients receiving prilocaine versus lidocaine.

    Science.gov (United States)

    Gutenberg, Lauren L; Chen, Jung-Wei; Trapp, Larry

    2013-01-01

    The purpose of this study was to measure and compare peak methemoglobin levels and times to peak methemoglobin levels following the use of prilocaine and lidocaine in precooperative children undergoing comprehensive dental rehabilitation under general anesthesia. Ninety children, 3-6 years of age, undergoing dental rehabilitation under general anesthesia were enrolled and randomly assigned into 3 equal groups: group 1, 4% prilocaine plain, 5 mg/kg; group 2, 2% lidocaine with 1:100,000 epinephrine, 2.5 mg/kg; and group 3, no local anesthetic. Subjects in groups 1 and 2 were administered local anesthetic prior to restorative dental treatment. Methemoglobin levels (SpMET) were measured and recorded throughout the procedure using a Masimo Radical-7 Pulse Co-Oximeter (Masimo Corporation, Irvine, Calif, RDS-1 with SET software with methemoglobin interface). Data were analyzed using chi-square, one-way analysis of variance (ANOVA), and Pearson correlation (significance of P < .05). Group 1 had a significantly higher mean peak SpMET level at 3.55% than groups 2 and 3 at 1.63 and 1.60%, respectively. The mean time to peak SpMET was significantly shorter for group 3 at 29.50 minutes than that of group 1 at 62.73 and group 2 at 57.50 minutes. Prilocaine, at 5 mg/kg in pediatric dental patients, resulted in significantly higher peak SpMET levels than lidocaine and no local anesthetic. In comparison to no local anesthetic, the administration of prilocaine and lidocaine caused peak SpMET levels to occur significantly later in the procedure.

  20. Effects of different general anesthetics on serum hemolysis and hepatic and muscular glycogenolysis in rats

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    E.F.A. Machado

    2009-11-01

    Full Text Available Anesthetics can affect the structure and biological function of tissues and systems differentially. The aim of the present study was to compare three injectable anesthetics generally used in experiments with animals in terms of the degree of hemolysis and glycogenolysis occurring after profound anesthesia. Twenty-four male Wistar rats (330-440 g were divided into three groups (N = 8: chloral hydrate (CH, ketamine + xylazine (KX, Zoletil 50® (zolazepam and tiletamine + xylazine (ZTX. After deep anesthesia, total blood was collected. The liver and white (WG and red gastrocnemius (RG muscles were also immediately removed. The degree of serum hemolysis was quantified on the basis of hemoglobin concentration (g/L. Hepatic and muscular glycogen concentrations (mmol/kg wet tissue were quantified by the phenol-sulfuric method. The CH and KX groups exhibited serum hemolysis (4.0 ± 2.2 and 1.9 ± 0.9 g/L, respectively; P < 0.05 compared to the ZTX group, which presented none. Only KX induced elevated glycogenolysis (mmol/kg wet tissue in the liver (86.9 ± 63.2 and in WG (18.7 ± 9.0 and RG (15.2 ± 7.2; P < 0.05. The CH and ZTX groups exhibited no glycogenolysis in the liver (164.4 ± 41.1 and 176.8 ± 54.4, respectively, WG (28.8 ± 4.4, 32.0 ± 6.5, respectively or RG (29.0 ± 4.9; 25.3 ± 8.6, respectively. Our data indicate that ZTX seems to be an appropriate general anesthetic for studies that seek to simultaneously quantify the concentration of glycogen and serum biochemical markers without interferences. ZTX is reasonably priced, found easily at veterinary markets, quickly induces deep anesthesia, and presents a low mortality rate.

  1. Effects of different general anesthetics on serum hemolysis and hepatic and muscular glycogenolysis in rats.

    Science.gov (United States)

    Machado, E F A; Normand, A C R; Nunes, L A S; Brenzikofer, R; Macedo, D V

    2009-11-01

    Anesthetics can affect the structure and biological function of tissues and systems differentially. The aim of the present study was to compare three injectable anesthetics generally used in experiments with animals in terms of the degree of hemolysis and glycogenolysis occurring after profound anesthesia. Twenty-four male Wistar rats (330-440 g) were divided into three groups (N = 8): chloral hydrate (CH), ketamine + xylazine (KX), Zoletil 50(R) (zolazepam and tiletamine) + xylazine (ZTX). After deep anesthesia, total blood was collected. The liver and white (WG) and red gastrocnemius (RG) muscles were also immediately removed. The degree of serum hemolysis was quantified on the basis of hemoglobin concentration (g/L). Hepatic and muscular glycogen concentrations (mmol/kg wet tissue) were quantified by the phenol-sulfuric method. The CH and KX groups exhibited serum hemolysis (4.0 +/- 2.2 and 1.9 +/- 0.9 g/L, respectively; P glycogenolysis (mmol/kg wet tissue) in the liver (86.9 +/- 63.2) and in WG (18.7 +/- 9.0) and RG (15.2 +/- 7.2; P glycogenolysis in the liver (164.4 +/- 41.1 and 176.8 +/- 54.4, respectively), WG (28.8 +/- 4.4, 32.0 +/- 6.5, respectively) or RG (29.0 +/- 4.9; 25.3 +/- 8.6, respectively). Our data indicate that ZTX seems to be an appropriate general anesthetic for studies that seek to simultaneously quantify the concentration of glycogen and serum biochemical markers without interferences. ZTX is reasonably priced, found easily at veterinary markets, quickly induces deep anesthesia, and presents a low mortality rate.

  2. General anesthetic and the risk of dementia in elderly patients: current insights

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    Hussain M

    2014-09-01

    Full Text Available Maria Hussain,1 Miles Berger,2 Roderic G Eckenhoff,3 Dallas P Seitz1 1Division of Geriatric Psychiatry, Department of Psychiatry, Queen’s University; 2Anesthesiology Department, Duke University Medical Center, Durham, NC, USA; 3Department of Anesthesiology and Critical Care, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA Abstract: In this review, we aim to provide clinical insights into the relationship between surgery, general anesthesia (GA, and dementia, particularly Alzheimer’s disease (AD. The pathogenesis of AD is complex, involving specific disease-linked proteins (amyloid-beta [Aß] and tau, inflammation, and neurotransmitter dysregulation. Many points in this complex pathogenesis can potentially be influenced by both surgery and anesthetics. It has been demonstrated in some in vitro, animal, and human studies that some anesthetics are associated with increased aggregation and oligomerization of Aß peptide and enhanced accumulation and hyperphosphorylation of tau protein. Two neurocognitive syndromes that have been studied in relation to surgery and anesthesia are postoperative delirium and postoperative cognitive dysfunction, both of which occur more commonly in older adults after surgery and anesthesia. Neither the route of anesthesia nor the type of anesthetic appears to be significantly associated with the development of postoperative delirium or postoperative cognitive dysfunction. A meta-analysis of case-control studies found no association between prior exposure to surgery utilizing GA and incident AD (pooled odds ratio =1.05, P=0.43. The few cohort studies on this topic have shown varying associations between surgery, GA, and AD, with one showing an increased risk, and another demonstrating a decreased risk. A recent randomized trial has shown that patients who received sevoflurane during spinal surgery were more likely to have progression of preexisting mild cognitive impairment compared to

  3. Can determining the minimum alveolar anesthetic concentration of volatile anesthetic be used as an objective tool to assess antinociception in animals?

    Science.gov (United States)

    Docquier, Marie-Agnes; Lavand'homme, Patricia; Ledermann, Christian; Collet, Valérie; De Kock, Marc

    2003-10-01

    We intended to evaluate the reliability of the minimum anesthetic alveolar concentration (MAC)-sparing effect as an objective measure of the antinociceptive properties of a drug. For this purpose, we tested different variables and analyzed the significance of the results obtained. In a first set of experiments, we studied rats under mechanical ventilation and sevoflurane anesthesia. Outcome variables such as gross purposeful movements consecutive to tail clamping, paw withdrawal consecutive to increasing pressure, and cardio-circulatory reactivity (MACBAR) after these stimuli were recorded. In a second set of experiment, sevoflurane-anesthetized rats under spontaneous breathing conditions were used. Thermal stimuli were compared with pressure. The MAC-sparing effect of several doses of sufentanil and clonidine was evaluated in both anesthetized and awake rodents. When considering the stimulus applied, larger concentrations of sevoflurane were required to suppress reactivity after tail clamp than after paw pressure or radiant heat (1.81 +/- 0.28 versus 1.45 +/- 0.22 and 1.53 +/- 0.26; P MAC values except the smallest one (0.005 micro g x kg(-1) x min(-1)) that significantly increased MACBAR in ventilated animals and both MAC and MACBAR in spontaneously breathing rodents (P MAC and MACBAR to the same degree. In awake animals submitted to radiant heat or pressure challenge, none of the clonidine doses nor sufentanil doses (0.005 and 0.07) were active. In conclusion, the MAC-sparing effect provides several reliable and quantifiable variables that allow comparison between different analgesic substances. However, the observations made are not simply the result of antinociceptive effects of the tested drugs but rather that of complex interactions between these drugs and a halogenated vapor. The MAC-sparing effect provides several variables that allow comparison between different analgesic substances. However, the observations made are not simply the result of the

  4. 全身麻醉药在脊髓内的作用机制%Subcortical mechanisms of general anesthetics

    Institute of Scientific and Technical Information of China (English)

    杨静; 张宏

    2008-01-01

    The spinal cord plays an important role in two general anesthetic end-points: analgesia and immobility in response to a noxious stimulus. The spinal components that may contribute to anesthetic actions include the central termination of sensory primary afferent neurons, interneurones and the cell bodies and initial axon segments of motor neurons, which are contained in dorsal horn and ventral horn respectively. Different general anesthetics have both presynaptic and postsynaptic effects to produce analgesia and immobility via multitude of cellular and subcellular sites identified as potential targets of anaesthetic action, such as diverse ligand-gated ion channels etc. This review will focus on anesthetic targets and molecular mechanisms mediated analgesia and immobility of general anesthetics in spinal cord.%脊髓是全身麻醉药抑制伤害性刺激体动反应和抗伤害效应的重要作用部位,含有不同配体门控离子受体等多个可能介导麻醉效应的靶点.不同药物在脊髓内经各自特异靶点通过多种分子机制发挥作用.现就全身麻醉药制动和镇痛效应在脊髓内的作用位点和分子机制作一综述.

  5. Influence of general anesthetics on brain development%全身麻醉药对脑发育的影响

    Institute of Scientific and Technical Information of China (English)

    蒋燕; 陈萍

    2008-01-01

    The mortality of neonatal anesthesia is decreasing with the development of anestheisia. Pharmacological blockade of Nmethyl-D-aspartate (NMDA) type glutamate receptors or over stimulation of γ-aminobutyric acid type A receptors has been reported to induce neuron apoptosis in the period of brain peak development. In view of the mechanisms of general anesthetics on central nervous system, the influence of anesthetic agents on brain development becomes the researching focus. Clarifying the mechanisms of anesthetics affecting brain development is very important for the rational use of anesthetics in neonates, as well as for the exploitation of new anesthetics.%随着麻醉领域的不断发展,新生儿麻醉的死亡率明显下降.一系列的研究表明,在脑发育高峰期,药物性阻断N-甲基-D-天(门)冬氨酸受体或过度激动γ-氨基丁酸A型受体会诱发神经细胞凋亡.鉴于全麻药在中枢神经系统的作用机制,麻醉药物对脑发育的影响成为人们研究的热点,其机制的阐明可能对新生儿麻醉用药的合理选用及新药的开发具有指导意义.

  6. The use of a volatile anesthetic regimen protects against acute normovolemic hemodilution induced myocardial depression in patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lorsomradee Sratwadee

    2009-01-01

    Full Text Available Background: Previous studies indicated that acute normovolemic hemodilution (ANH was associated with a depression of myocardial function in coronary surgery patients with baseline heart rate faster than 90 bpm. It was suggested that this phenomenon could be explained by the occurrence of myocardial ischemia. In the present study, we hypothesized that the cardioprotective properties of a volatile anesthetic regimen might protect against the ANH related myocardial functional impairment. Materials and Methods: Forty elective coronary surgery patients with baseline heart rate faster than 90 bpm were randomly allocated to receive different anesthetic regimens. Group A (n = 20 received midazolam-based anesthesia. Group B (n = 20 received a sevoflurane-based anesthesia. Five-lead electrocardiogram, pulse oximetry, capnography, radial arterial pressure, and Swan Ganz continuous thermodilution cardiac output via right internal jugular vein were monitored. Measurements were obtained before and after ANH. Data were compared using paired t test. All data were expressed as mean ± SD. Data were considered significant if P < 0.05. Results: After ANH, systemic vascular resistance was slightly decreased in group A while there was a significant decrease in group B. In group A, cardiac output was slightly decreased from 5.07±1.17 l/min to 5.02±1.28 l/min after ANH, whereas in group B, cardiac output was significantly increased from 4.84±1.21 l/min to 6.02±1.28 l/min after ANH. Conclusion: In coronary surgery patients, with baseline heart rate faster than 90 bpm, anesthesia with sevoflurane during ANH was associated with an improvement in myocardial function after ANH, which was not present in patients anesthetized with midazolam.

  7. [New anesthetics].

    Science.gov (United States)

    Malamed, S F

    2000-01-01

    Since the introduction of cocaine local analgesia in 1886, and the subsequent development of procaine (1904) and other closely related ester-type compounds, dentistry has prided itself on being as close to 'painless' as possible. In the late 1940s the newest group of the local anesthetic compounds, the amides, was introduced. The initial amide local analgesic, lignocaine (Xylocaine), revolutionised pain control in dentistry worldwide. In succeeding years other amide-type local anesthetics, mepivacaine, prilocaine, bupivacaine and etidocaine, were introduced. They gave the dental practitioner a local anesthetic armamentarium which provided pulpal analgesia for periods of from 20 minutes (mepivacaine) to as long as three hours (bupivacaine and etidocaine with adrenaline). In addition these popular drugs proved to be more rapid-acting than the older ester-type drug and, at least from the perspective of allergenicity, more safe. In 1976, in Germany, the newest amide local analgesic, carticaine HCl was introduced into dentistry. Articaine (the generic name was changed) possesses properties similar to lignocaine but has additional properties which made the drug quite attractive to the general dental practitioner. In 1986 articaine was introduced in North America (Canada) where it has become the most used local anesthetic, supplanting lignocaine. Articaine has been approved for use in the United Kingdom. In this introductory discussion we review the development of articaine and discuss its place in the dental local analgesic armamentarium.

  8. The anesthetic agent as an extra-integumentary foreign body in the respiratory tract. A new theory of general anesthesia.

    Science.gov (United States)

    Baggot, M G

    1977-01-01

    Two cases are cited of patients who sometimes exhibited a condition of temporary unconsciousness which proceeded to spontaneous recovery without harmful sequelae. This type of cerebral arrest is frequently called general anesthesia:however, these patients had not received any drugs. What they did have was an irritant in the respiratory passages as shown by coughing. Three cases of general anesthesia are described wherein the duration of the phenomenon appeared to be partly due to the presence of an extra-integumentary foreign body, confined to the respiratory passages. In this trio there was evidence that the drugs did not affect the patients in any unusual way, whatever their effects on whichever side of the alveolar walls. Many anesthetic agents act like unabsorbable foreign bodies, in that they enter and leave the body unchanged, despite the fact that they do pierce the integument. Of course, almost everything, except inspirable and expirable air, but including anesthetic agents, is a foreign body in the respiratory tract. On the basis of these considerations, I suggest that one way, in which general anesthetic agents work, is an extra-integumentary foreign bodies, causing Reflex Coma by irritating or stimulating the trigger points in the walls of the respiratory tract, thereby arresting the cerebrum.

  9. 全身麻醉药的安全性研究%The Security Study of General Anesthetics

    Institute of Scientific and Technical Information of China (English)

    赖延锦

    2012-01-01

      全身麻醉药是抑制中枢系统的药物,分为吸入和静脉麻醉药,能使患者意识、感觉和反射暂时消失,有利于外科手术的进行,其临床使用安全性越来越受到人们的关注。本文对几种常见全麻药的安全性进行探讨,确保广大医务人员能合理有效使用该类药品,保证人民的生命健康。%  General anesthetics is the inhibition of central nervous system drugs, it is divided into the inhalation anesthesia and intravenous anesthetics, it can make the patient consciousness, sensation and a reflex disappear temporarily, and it is advantageous to make surgical operation ,people pay more and more attention to the clinical use of security. This paper discusses several common general anesthetics security, it ensures that the medical staff can effectively use the drugs and keep the people healthy.

  10. Interference of diabetes on volatile anesthetic-induced myocardial protection%糖尿病与吸入性麻醉药心肌保护作用研究新进展

    Institute of Scientific and Technical Information of China (English)

    李毅; 江晓菁; 师恩祎

    2009-01-01

    Volatile anesthetic pre-or post-conditioning presents protective effects against iscbemic damage of myocardium,by activating endogeneous protection mechanisms.Recent studies show that hyperglycemia may block anesthetic conditioning-induced protective effect,and that volatile anesthetics inhibit insulin release,producing hyperglycemia.Volatile anesthetic-produced myocardial protective effects may have a promising future in clinical application,and more attention should be paid on the relationship between diabetes and myocardial protection of volatile anesthetic.%目前研究表明,对于心肌缺血/再灌注(isehemic/reperfusion,I/R)损伤,适当的刺激可以激活机体的内源性保护机制,即缺血预处理(ischemic preconditioning,IPC)和缺血后处理(ischemic postconditioning,I-post),最终达到心肌保护效果.同时现有的研究发现,吸人性麻醉药同样可以诱导产生内源性的心肌保护作用,其作用机制及临床应用前景成为目前广泛关注的焦点,现就以七氟醚为代表的吸入性麻醉药的心肌保护作用及糖尿病与吸人性麻醉药心肌保护作用的关系作一简要综述.

  11. Day-surgery patients anesthetized with propofol have less postoperative pain than those anesthetized with sevoflurane.

    LENUS (Irish Health Repository)

    Tan, Terry

    2012-02-01

    BACKGROUND: There have been recent studies suggesting that patients anesthetized with propofol have less postoperative pain compared with patients anesthetized with volatile anesthetics. METHODS: In this randomized, double-blind study, 80 patients undergoing day-case diagnostic laparoscopic gynecological surgery were either anesthetized with IV propofol or sevoflurane. The primary outcome measured was pain on a visual analog scale. RESULTS: Patients anesthetized with propofol had less pain compared with patients anesthetized with sevoflurane (P = 0.01). There was no difference in any of the other measured clinical outcomes. CONCLUSIONS: The patients anesthetized with propofol appeared to have less pain than patients anesthetized with sevoflurane.

  12. Anesthetic Techniques and Cancer Recurrence after Surgery

    Directory of Open Access Journals (Sweden)

    Vincenzo Fodale

    2014-01-01

    Full Text Available Many of the most common anesthetics are used in surgical oncology, yet effects on cancer cells are still not known. Anesthesia technique could differentially affect cancer recurrence in oncologic patients undergoing surgery, due to immunosuppression, stimulation of angiogenesis, and dissemination of residual cancer cells. Data support the use of intravenous anesthetics, such as propofol anesthesia, thanks to antitumoral protective effects inhibiting cyclooxygenase 2 and prostaglandins E2 in cancer cells, and stimulation of immunity response; a restriction in the use of volatile anesthetics; restriction in the use of opioids as they suppress humoral and cellular immunity, and their chronic use favors angiogenesis and development of metastases; use of locoregional anesthesia compared with general anesthesia, as locoregional appears to reduce cancer recurrence after surgery. However, these findings must be interpreted cautiously as there is no evidence that simple changes in the practice of anesthesia can have a positive impact on postsurgical survival of cancer patients.

  13. Anesthetic strategy during endovascular therapy: General anesthesia or conscious sedation? (GOLIATH - General or Local Anesthesia in Intra Arterial Therapy) A single-center randomized trial.

    Science.gov (United States)

    Simonsen, Claus Z; Sørensen, Leif H; Juul, Niels; Johnsen, Søren P; Yoo, Albert J; Andersen, Grethe; Rasmussen, Mads

    2016-12-01

    Endovascular therapy after acute ischemic stroke due to large vessel occlusion is now standard of care. There is equipoise as to what kind of anesthesia patients should receive during the procedure. Observational studies suggest that general anesthesia is associated with worse outcomes compared to conscious sedation. However, the findings may have been biased. Randomized clinical trials are needed to determine whether the choice of anesthesia may influence outcome. The objective of GOLIATH (General or Local Anestesia in Intra Arterial Therapy) is to examine whether the choice of anesthetic regime during endovascular therapy for acute ischemic stroke influence patient outcome. Our hypothesis is that that conscious sedation is associated with less infarct growth and better functional outcome. GOLIATH is an investigator-initiated, single-center, randomized study. Patients with acute ischemic stroke, scheduled for endovascular therapy, are randomized to receive either general anesthesia or conscious sedation. The primary outcome measure is infarct growth after 48-72 h (determined by serial diffusion-weighted magnetic resonance imaging). Secondary outcomes include 90-day modified Rankin Scale score, time parameters, blood pressure variables, use of vasopressors, procedural and anesthetic complications, success of revascularization, radiation dose, and amount of contrast media. Choice of anesthesia may influence outcome in acute ischemic stroke patients undergoing endovascular therapy. The results from this study may guide future decisions regarding the optimal anesthetic regime for endovascular therapy. In addition, this study may provide preliminary data for a multicenter randomized trial. © 2016 World Stroke Organization.

  14. Asymmetry Effects in Chinese Stock Markets Volatility: A Generalized Additive Nonparametric Approach

    OpenAIRE

    Hou, Ai Jun

    2007-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modeling return volatility with the parametric GARCH family models. This paper therefore applies a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chin...

  15. Estimating and Forecasting Generalized Fractional Long Memory Stochastic Volatility Models

    NARCIS (Netherlands)

    S. Peiris (Shelton); M. Asai (Manabu); M.J. McAleer (Michael)

    2016-01-01

    textabstractIn recent years fractionally differenced processes have received a great deal of attention due to its flexibility in financial applications with long memory. This paper considers a class of models generated by Gegenbauer polynomials, incorporating the long memory in stochastic volatility

  16. The effects of general anesthetics on ESR spectra of spin labels in phosphatidylcholine vesicles containing purified Na,K-ATPase or microsomal protein

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Makiko, E-mail: shibu@den.hokudai.ac.jp [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Hiraoki, Toshifumi [Division of Applied Physics, Graduate School of Engineering, Hokkaido University (Japan); Kimura, Kunie; Fukushima, Kazuaki [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Suzuki, Kuniaki [Department of Molecular Cell Pharmacology, Graduate School of Dental Medicine, Hokkaido University (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer We studied the effects of general anesthetics on liposome using ESR spectra. Black-Right-Pointing-Pointer Two spin labels, 5-DSA and 16-DSA, were located in different position in liposome. Black-Right-Pointing-Pointer Anesthetics did not change the environment around the spin labels in the liposome. Black-Right-Pointing-Pointer Anesthetics remained on the surface of the lipid bilayer of liposome. Black-Right-Pointing-Pointer Proteins in the liposome did not change the effects of anesthetics on liposome. - Abstract: We investigated the effects of general anesthetics on liposome containing spin labels, 5-doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA), and purified Na,K-ATPase or membrane protein of microsome using an electron spin resonance (ESR) spectroscopy. The spectra of 16-DSA in liposomes with both proteins showed three sharp signals compared with 5-DSA. The difference in the order parameter S value of 5-DSA and 16-DSA suggested that the nitroxide radical location of 5-DSA and 16-DSA were different in the membrane bilayer. The results were almost the same as those obtained in liposomes without proteins. The addition of sevoflurane, isoflurane, halothane, ether, ethanol and propofol increased the intensity of the signals, but the clinical concentrations of anesthetics did not significantly alter the S and {tau} values, which are indices of the fluidity of the membrane. These results suggest that anesthetics remain on the surface of the lipid bilayer and do not act on both the inside hydrophobic area and the relatively hydrophilic area near the surface. These results and others also suggest that the existence of Na,K-ATPase and microsomal proteins did not affect the environment around the spin labels in the liposome and the effects of anesthetics on liposome as a model membrane.

  17. Comparison of the effects of PEEP levels on respiratory mechanics and elimination of volatile anesthetic agents in patients undergoing laparoscopic cholecystectomy; a prospective, randomized, clinical trial.

    Science.gov (United States)

    Arinalp, Hüsnü Mert; Bakan, Nurten; Karaören, Gülşah; Şahin, Ömer Torun; Çeliksoy, Emre

    2016-06-23

    In laparoscopic procedures, intraabdominal carbon dioxide (CO2) insufflation can cause decreased compliance, increased airway resistance, and impaired ventilation-perfusion ratios. We aimed to investigate the effects of intraoperative positive end-expiratory pressure (PEEP) treatment on respiratory dynamics and elimination time of volatile anesthetic agents. In the present study, 75 ASA I-II patients were randomized into 3 groups to receive 0 cmH2O PEEP (group I), 5 cmH2O PEEP (group II), or 8 cmH2O PEEP (group III). Hemodynamic parameters, peak and plateau inspiratory airway pressures (Ppeak, Pplateau), compliance values, the ratio of the fractions of inspired and expired concentration of sevoflurane (Fi/Fexp sevoflurane) at 1 MAC, times from 1 to 0.3 and 0.1 MAC and values for pulmonary function tests (PFT) were recorded. Ppeak and Pplateau in group III were higher; compliance values in group I and the extent of reduction in postoperative forced vital capacity (FVC) in group III were lower than those in the other groups (P < 0.05). No significant difference was observed between the groups regarding times from 1 to 0.3 MAC and times from 0.3 to 0.1 MAC. It was found that 8 cmH2O PEEP increased compliance without clinically significant pulmonary deterioration and that 8 cmH2O PEEP led to less impairment in postoperative PFTs compared to 0 and 5 cmH2O PEEP but had no effect on sevoflurane elimination time.

  18. COMPARISON OF ONDANSETRON IN TWO DIFFERENT DOSES IN THE REDUCTION OF POST ANESTHETIC SHIVERING AFTER GENERAL ANESTHESIA

    Directory of Open Access Journals (Sweden)

    Umar Qadir

    2015-03-01

    Full Text Available GOALS OF STUDY: Ondansetron, a specific 5 - HT 3 antagonist, conventionally used as an antiemetic may also affect perioperative thermoregulation and Post Anesthetic Shivering (PAS. Therefore, we decided to compare the effect of Ondansetron in 2 different doses (4mg and 8 mg given just before the induction of general anesthesia on the incidence of PAS. METHODS: A double blind, placebo - controlled study was adopted to study 90 patients divided into 3 equal groups receiving general anesthesia for elective general surgeries. Groups – A, B and C received Ondansetron 4 mg, 8mg and Normal Saline 4 ml I/V respectively immediately before anesthetic induction. Core and peripheral temperatures were documented every 10 minutes from baseline to recovery from anaesthesia. After recovery from anaesthesia the occurrence of shivering was documented. Data was entered in excel and statistically important tests were done. P <0.05 was considered as significant. RESULTS: The incidence of PAS was 60% in the Group - C compared with 16.7% in Group - B , and 36.7% in Group - A. PAS was significantly low in the group receiving 8 mg ondansetron. CONCLUSIONS: Ondansetron 8 mg when compared with Ondansetron 4 mg given before the induction of anesthesia, reduces the incidence of PAS in adults significantly, without affecting the core – to - peripheral redistribution of temperature. The incidence of shivering was highest in the control group (60% with an intermediate incidence in the group receiving 4mg Ondansetron (36.7% and a lowest incidence in the group receiving 8mg Ondansetron (16.7%. CONTEXT: Different observations suggest that the serotonergic system has a role in the control of postanesthetic shivering. Ondansetron is a specific 5 - HT 3 antagonist that may affect perioperative thermoregulation and PAS. Therefore, we decided to compare the effect of Ondansetron, in 2 different doses (4mg and 8 mg given just before the induction of general anesthesia, on the

  19. Dental treatment need and dental general anesthetics among preschool-age children with cleft lip and palate in northern Finland.

    Science.gov (United States)

    Lehtonen, Ville; Sándor, George K; Ylikontiola, Leena P; Koskinen, Sari; Pesonen, Paula; Harila, Virpi; Anttonen, Vuokko

    2015-08-01

    Cleft lip and palate incidence is high in northern Finland. This study aimed to investigate the proportion of children in need of restorative dental treatment among cleft lip and palate patients in northern Finland, as well as their need for dental treatment under general anesthesia. The records of 183 cleft lip and palate patients, treated in Oulu University Hospital from 1997 to 2013, were reviewed. Data on dental caries were analyzed in association with cleft type, considering also the presence of syndromes. The frequency of dental general anesthetic (DGA) use, and of treatments, were also analyzed. Dental treatment need was most frequently observed, in this rather limited study population, in patients with the most severe deformities, namely bilateral cleft lip and palate, of whom 60% had caries. Among the study population, 11.5% (n = 21) had a syndrome. Of those, 57.1% had dental caries at the age of 3 or 6 yr, and only four could be treated without a DGA. Dental treatment under general anesthesia was performed in 14.8% of cleft patients without a syndrome, but in 38.1% of those with a syndrome. General anaesthesia is required for the provision of dental care more often in cleft (17.5%) than in non-cleft (0.2%) patients, and especially for those with a syndrome. © 2015 Eur J Oral Sci.

  20. Anesthetic and airway management of general anesthesia in a patient with Meckel-Gruber syndrome.

    Science.gov (United States)

    Miyazu, Mitsunori; Sobue, Kazuya; Ito, Hiroaki; Azami, Takafumi; Ito, Shoji; Takeuchi, Akinori; Sasano, Hiroshi; Tsuda, Takako; Katsuya, Hirotada

    2005-01-01

    Meckel-Gruber syndrome, characterized by occipital encephalocele, microcephaly, polydactyly, cleft lip or palate, mandibular micrognathism, and anatomical abnormality of the larynx and tongue, along with other associated malformations, is in the list of diseases associated with difficult airway. However, there has been no report on the management of general anesthesia and airway management for such patients. A 2-year-old girl with Meckel-Gruber syndrome was scheduled for cardioplasty and gastrostomy for gastroesophageal reflux under general anesthesia. Preoperative examination revealed obesity, microgenia, dysspondylism, proteinuria, hypoplastic kidneys, and stenosis of the anal canal. Although we anticipated some difficulty with the intubation and prepared several alternative methods for intubation, such as a bronchofiberscope and a laryngeal mask airway, tracheal intubation was completed without difficulty using conventional laryngoscopy after inhalational induction with sevoflurane. Because most patients with this syndrome die before and shortly after delivery, those who survive to some age might have less severe deformities.

  1. General Anesthetic Versus Light Sedation: Effect on Pediatric Endoscopy Wait Times

    Directory of Open Access Journals (Sweden)

    Christine Edwards

    2013-01-01

    Full Text Available BACKGROUND: Wait times are an important measure of health care system effectiveness. There are no studies describing wait times in pediatric gastroenterology for either outpatient visits or endoscopy. Pediatric endoscopy is performed under light sedation or general anesthesia. The latter is hypothesized to be associated with a longer wait time due to practical limits on access to anesthesia in the Canadian health care system.

  2. A General Multidimensional Monte Carlo Approach for Dynamic Hedging under Stochastic Volatility

    Directory of Open Access Journals (Sweden)

    Daniel Bonetti

    2015-01-01

    Full Text Available We propose a feasible and constructive methodology which allows us to compute pure hedging strategies with respect to arbitrary square-integrable claims in incomplete markets. In contrast to previous works based on PDE and BSDE methods, the main merit of our approach is the flexibility of quadratic hedging in full generality without a priori smoothness assumptions on the payoff. In particular, the methodology can be applied to multidimensional quadratic hedging-type strategies for fully path-dependent options with stochastic volatility and discontinuous payoffs. In order to demonstrate that our methodology is indeed applicable, we provide a Monte Carlo study on generalized Föllmer-Schweizer decompositions, locally risk minimizing, and mean variance hedging strategies for vanilla and path-dependent options written on local volatility and stochastic volatility models.

  3. ALGORITHM FOR GENERALIZED GARMAN EQUATION IN OPTION PRICING OF A FINANCIAL DERIVATIVES WITH STOCHASTIC VOLATILITY MODELS

    Directory of Open Access Journals (Sweden)

    Maxim Ioan

    2009-05-01

    Full Text Available In our paper we build a reccurence from generalized Garman equation and discretization of 3-dimensional domain. From reccurence we build an algorithm for computing values of an option based on time, momentan volatility of support and value of support on a

  4. The effect of different anesthetics on tumor cytotoxicity by natural killer cells.

    Science.gov (United States)

    Tazawa, Kazumasa; Koutsogiannaki, Sophia; Chamberlain, Matthew; Yuki, Koichi

    2017-01-15

    A number of retrospective studies have suggested that choice of anesthetic drugs during surgical tumor resection might affect tumor recurrence/metastasis, or outcome of patients. The recent study showed that volatile anesthetics-based general anesthesia was associated with the worse outcomes than intravenous anesthetics-based general anesthesia. However, the underlying mechanism is yet to be determined. Because natural killer (NK) cells are implicated as important immune cells for tumor recurrence/metastasis in the perioperative period, we examined the effect of different anesthetics on NK cell-mediated tumor cytotoxicity. Because adhesion molecule leukocyte function-associated antigen-1 (LFA-1) is functionally important in NK cells and is inhibited by commonly used volatile anesthetics isoflurane and sevoflurane, we hypothesized that these anesthetics would attenuate NK cell-mediated cytotoxicity. Using human NK cell line NK92-MI cells and tumor cell line K562 cells as a model system, we performed cytotoxicity, proliferation, conjugation and degranulation assays. Lytic granule polarization was also assessed. We showed that isoflurane, sevoflurane and LFA-1 inhibitor BIRT377 attenuated cytotoxicity, and reduced conjugation and polarization, but not degranulation of NK cells. Our data suggest that isoflurane and sevoflurane attenuated NK cell-mediated cytotoxicity at least partly by their LFA-1 inhibition in vitro. Whether or not isoflurane and sevoflurane attenuate NK cell-mediated tumor cytotoxicity in patients needs to be determined in the future. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. 全麻药物对脑神经毒作用的研究进展%Recend development on toxic effects of general anesthetics on cerebral neurons

    Institute of Scientific and Technical Information of China (English)

    罗铁山; 陶国才

    2010-01-01

    A growing body of evidence from cells culture, rodents and sub-human primates's experimental study suggest that clinical commonly used general anesthetics not only can cause neurotoxicity to neuronal cells of different periods with subsequent central nervous system injury, especially during the brain growth spurt period, but also affect learning and memory function. We review the evidence of neurotoxic effects of anesthetic agents and hypothesis of mechanism, in order to allow people to understand the latest research progress of general anesthetics on toxic effects and change some concept of clinical anesthesia.%从细胞培养、啮齿类动物和非人类灵长类动物的实验研究中得到越来越多的证据:临床常用全麻药物对各期脑神经细胞产生毒性作用,损伤中枢神经系统,特别对处于发育高峰期的大脑影响更大,并影响以后的学习记忆功能.现综述这些事实及目前全麻药物神经毒性作用的机制假设,目的 是让人们对全麻药物毒性作用的最新研究进展有一了解,转变临床麻醉的一些观念.

  6. Declining Volatility, a General Property of Disparate Systems: From Fossils, to Stocks, to the Stars

    CERN Document Server

    Lieberman, Bruce S

    2012-01-01

    There may be structural principles pertaining to the general behavior of systems that lead to similarities in a variety of different contexts. Classic examples include the descriptive power of fractals, the importance of surface area to volume constraints, the universality of entropy in systems, and mathematical rules of growth and form. Documenting such overarching principles may represent a rejoinder to the Neodarwinian synthesis that emphasizes adaptation and competition. Instead, these principles could indicate the importance of constraint and structure on form and evolution. Here we document a potential example of a phenomenon suggesting congruent behavior of very different systems. We focus on the notion that universally there has been a tendency for more volatile entities to disappear from systems such that the net volatility in these systems tends to decline. We specifically focus on origination and extinction rates in the marine animal fossil record, the performance of stocks in the stock market, and...

  7. 全麻药物机制研究的几点新进展%The research progress of general anesthetics on the brain function

    Institute of Scientific and Technical Information of China (English)

    李肇端; 刘兴奎; 喻田

    2013-01-01

    背景 全身麻醉应用于临床已有160多年的历史,但麻醉药导致相应的行为改变如意识丧失、遗忘和镇痛的神经生理机制是什么,至今仍不清楚,尤其对于其中最具特征性的全麻意识消失,人们对其了解最为肤浅. 目的 综述全身麻醉药对离子通道和受体、各脑电活动的影响和脑功能的变化. 内容 全麻机制的研究可以分6个层次,分别是:分子水平、突触水平、细胞水平、神经微环路水平、系统水平(脑区)以及行为水平.总结近年来全身麻醉药(以下简称全麻药)在不同结构水平研究的最新进展,并从宏观上探讨全麻药对脑功能的影响. 趋向 多种实验技术相结合将为全麻机制的研究提供新的方法.%Background The clinical application of general anesthesia has been used for more than 160 years,however,neurophysiological mechanism of corresponding behavioral changes caused by anesthetic such as loss of consciousness,amnesia and analgesic are still unclear,especially for the unconsciousness which we hardly understood.Objective We reviewed the impacts of general anesthetics on ion channels and corresonding receptors,as well as brain electrical activity and changes in brain functions.Content The research of general anesthesia mechanisms can be divided into six levels:the molecular,synaptic,cellular,neural micro-circuit,system (brain areas) and behavioral level.This review summarized the progress about general anesthetics on different levels and explored the change of brain functions by general anesthetics on macro level.Trend The combination of different kinds of experimental techniques could provide new approaches for general anesthesia mechanism.

  8. Nitrogen narcosis and pressure reversal of anesthetic effects in node of Ranvier.

    Science.gov (United States)

    Kendig, J J

    1984-01-01

    To compare sodium channel block by hyperbaric nitrogen with that induced by other anesthetics and to examine the basis for pressure antagonism to anesthetic condition block, voltage clamped nodes of Ranvier were exposed to nitrogen at pressures at 1-14 atm alone and in combination with helium to a total pressure of up to 100 atm. At 7 and 14 atm nitrogen, sodium currents were reversibly depressed without accompanying changes in the current-voltage relation. The curve relating steady-state inactivation (h infinity) to voltage was shifted in the hyperpolarizing direction, as is the case with other general anesthetic agents. The time constant of inactivation (tau h) was slightly decreased at depolarized potentials. The preceding companion paper demonstrated an opposite effect of hyperbaric helium on the properties of sodium inactivation. Addition of helium pressure in the presence of nitrogen at 14 atm did not increase peak sodium current with inactivation maximally removed, but it did shift the h infinity curve back toward control levels, thus increasing sodium current at points on the slope of the curve. It is proposed that these opposing shifts in steady-state inactivation levels are the basis for pressure antagonism to anesthetic conduction block. In the case of inert gases and volatile anesthetic agents, the antagonism may be direct but has not been shown to be so. In the case of the local anesthetic benzocaine, differences in the voltage dependence of anesthetic and pressure-induced changes in tau h indicate the antagonism is indirect.

  9. The General Anesthetic Propofol Excites Nociceptors by Activating TRPV1 and TRPA1 Rather than GABAA Receptors*

    Science.gov (United States)

    Fischer, Michael J. M.; Leffler, Andreas; Niedermirtl, Florian; Kistner, Katrin; Eberhardt, Mirjam; Reeh, Peter W.; Nau, Carla

    2010-01-01

    Anesthetic agents can induce a paradox activation and sensitization of nociceptive sensory neurons and, thus, potentially facilitate pain processing. Here we identify distinct molecular mechanisms that mediate an activation of sensory neurons by 2,6-diisopropylphenol (propofol), a commonly used intravenous anesthetic known to elicit intense pain upon injection. Clinically relevant concentrations of propofol activated the recombinant transient receptor potential (TRP) receptors TRPA1 and TRPV1 heterologously expressed in HEK293t cells. In dorsal root ganglion (DRG) neurons, propofol-induced activation correlated better to expression of TRPA1 than of TRPV1. However, pretreatment with the protein kinase C activator 4β-phorbol 12-myristate 13-acetate (PMA) resulted in a significantly sensitized propofol-induced activation of TRPV1 in DRG neurons as well as in HEK293t cells. Pharmacological and genetic silencing of both TRPA1 and TRPV1 only partially abrogated propofol-induced responses in DRG neurons. The remaining propofol-induced activation was abolished by the selective γ-aminobutyric acid, type A (GABAA) receptor antagonist picrotoxin. Propofol but not GABA evokes a release of calcitonin gene-related peptide, a key component of neurogenic inflammation, from isolated peripheral nerves of wild-type but not TRPV1 and TRPA1-deficient mice. Moreover, propofol but not GABA induced an intense pain upon intracutaneous injection. As both the release of calcitonin gene-related peptide and injection pain by propofol seem to be independent of GABAA receptors, our data identify TRPV1 and TRPA1 as key molecules for propofol-induced excitation of sensory neurons. This study warrants further investigations into the role of anesthetics to induce nociceptor sensitization and to foster postoperative pain. PMID:20826794

  10. Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status

    National Research Council Canada - National Science Library

    Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

    2014-01-01

    .... This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration-awake (MAC-Awake...

  11. The effect of preoperative suggestions on perioperative dreams and dream recalls after administration of different general anesthetic combinations: a randomized trial in maxillofacial surgery.

    Science.gov (United States)

    Gyulaházi, Judit; Varga, Katalin; Iglói, Endre; Redl, Pál; Kormos, János; Fülesdi, Béla

    2015-01-01

    Images evoked immediately before the induction of anesthesia with the help of suggestions may influence dreaming during anesthesia.The aim of the study was to assess the incidence of evoked dreams and dream recalls by employing suggestions before induction of anesthesia while administering different general anesthetic combinations. This is a single center, prospective randomized including 270 adult patients scheduled for maxillofacial surgical interventions. Patients were assigned to control, suggestion and dreamfilm groups according to the psychological method used. According to the anesthetic protocol there were also three subgroups: etomidate & sevoflurane, propofol & sevoflurane, propofol & propofol groups. Primary outcome measure was the incidence of postoperative dreams in the non-intervention group and in the three groups receiving different psychological interventions. Secondary endpoint was to test the effect of perioperative suggestions and dreamfilm-formation training on the occurrance of dreams and recallable dreams in different general anesthesiological techniques. Dream incidence rates measured in the control group did not differ significantly (etomidate & sevoflurane: 40%, propofol & sevoflurane: 26%, propofol & propofol: 39%). A significant increase could be observed in the incidence rate of dreams between the control and suggestion groups in the propofol & sevoflurane (26%-52%) group (p = 0.023). There was a significant difference in the incidence of dreams between the control and dreamfilm subgroup in the propofol & sevoflurane (26% vs. 57%), and in the propofol & propofol group (39% vs.70%) (p = 0.010, and p = 0.009, respectively). Similar to this, there was a significant difference in dream incidence between the dreamfilm and the suggestion subgroups (44% vs. 70%) in the propofol & propofol group (p = 0.019). Propofol as an induction agent contributed most to dream formation and recalls (χ2-test p value: 0.005). The content of images and dreams

  12. Potent Inhalational Anesthetics for Dentistry.

    Science.gov (United States)

    Satuito, Mary; Tom, James

    2016-01-01

    Nitrous oxide and the volatile inhalational anesthetics have defined anxiety and pain control in both dentistry and medicine for over a century. From curious experimentation to spectacular public demonstrations, the initial work of 2 dentists, Horace Wells and William T. G. Morton, persists to this day in modern surgery and anesthesia. This article reviews the history, similarities, differences, and clinical applications of the most popular inhalational agents used in contemporary dental surgical settings.

  13. Anesthetic management of ostriches.

    Science.gov (United States)

    Cornick, J L; Jensen, J

    1992-06-01

    We evaluated and characterized several anesthetic induction protocols used to facilitate intubation and anesthetic maintenance with isoflurane in 7 adult ostriches and 1 juvenile ostrich. Induction protocols included IV administration of zolazepam/tiletamine, IV administration of diazepam/ketamine with and without xylazine, IV administration of xylazine/ketamine, IM administration of carfentanil or xylazine/carfentanil, and mask induction with isoflurane. General anesthesia was maintained with isoflurane in 100% oxygen for various procedures, including proventriculotomy (6 birds), tibial (1 bird) or mandibular (1 bird) fracture repair, and drainage of an iatrogenic hematoma (1 bird). Heart rate and respiratory rate varied greatly among birds. The arterial blood pressure values recorded from 6 of the birds during maintenance of general anesthesia were higher than values recorded for most mammalian species, but were comparable to values reported for awake chickens and turkeys.

  14. Multiple anesthetics for a patient with stiff-person syndrome.

    Science.gov (United States)

    Cassavaugh, Jessica M; Oravitz, Todd M

    2016-06-01

    Stiff-person syndrome is a progressive disease of muscle rigidity and spasticity due to a deficiency in the production of γ-aminobutyric acid. Because of the rarity of the condition, little is known about effects of anesthesia on patients with stiff-person syndrome. This report describes the clinical course for a single patient with stiff-person syndrome who received general anesthesia on 3 separate occasions. Her anesthetics included use of both neuromuscular blockade and volatile agents. Unlike several previous reports regarding anesthesia and stiff-person syndrome, the postoperative period for this patient did not require prolonged intubation or result in any residual weakness.

  15. Generalized Fractional Processes with Long Memory and Time Dependent Volatility Revisited

    Directory of Open Access Journals (Sweden)

    M. Shelton Peiris

    2016-09-01

    Full Text Available In recent years, fractionally-differenced processes have received a great deal of attention due to their flexibility in financial applications with long-memory. This paper revisits the class of generalized fractionally-differenced processes generated by Gegenbauer polynomials and the ARMA structure (GARMA with both the long-memory and time-dependent innovation variance. We establish the existence and uniqueness of second-order solutions. We also extend this family with innovations to follow GARCH and stochastic volatility (SV. Under certain regularity conditions, we give asymptotic results for the approximate maximum likelihood estimator for the GARMA-GARCH model. We discuss a Monte Carlo likelihood method for the GARMA-SV model and investigate finite sample properties via Monte Carlo experiments. Finally, we illustrate the usefulness of this approach using monthly inflation rates for France, Japan and the United States.

  16. A Hull and White Formula for a General Stochastic Volatility Jump-Diffusion Model with Applications to the Study of the Short-Time Behavior of the Implied Volatility

    Directory of Open Access Journals (Sweden)

    Elisa Alòs

    2008-01-01

    Full Text Available We obtain a Hull and White type formula for a general jump-diffusion stochastic volatility model, where the involved stochastic volatility process is correlated not only with the Brownian motion driving the asset price but also with the asset price jumps. Towards this end, we establish an anticipative Itô's formula, using Malliavin calculus techniques for Lévy processes on the canonical space. As an application, we show that the dependence of the volatility process on the asset price jumps has no effect on the short-time behavior of the at-the-money implied volatility skew.

  17. Anesthetics interacting with lipid rafts.

    Science.gov (United States)

    Bandeiras, Cátia; Serro, Ana Paula; Luzyanin, Konstantin; Fernandes, Anabela; Saramago, Benilde

    2013-01-23

    The exact mechanism by which anesthetics induce cell membrane-mediated modifications is still an open question. Although the fluidization effect of the anesthetic molecules on the cellular membrane is widely recognized, it is not known if anesthetics show any preference for specific membrane domains, namely the lipid rafts. The importance of these membrane micro-domains derives from the fact that they have been associated with cell signaling pathways, as well as with specific drug interactions. The objective of this work is to contribute for the elucidation of this question through the comparison of the anesthetic interactions with membranes of various lipid compositions. Liposomes prepared with an equimolar mixture of POPC, sphingomyelin and cholesterol, were chosen as models for lipid rafts. The interactions of these liposomes with two local anesthetics, tetracaine and lidocaine, and one general anesthetic, propofol, were studied. The effect of cholesterol was investigated by comparing anesthetic interactions with POPC/SM liposomes and POPC/SM/CHOL liposomes. The following experimental techniques were used: quartz crystal microbalance with dissipation, differential scanning calorimetry and phosphorus nuclear magnetic resonance. Although the liposomes investigated by the different techniques are not in the same conditions, it is possible to assemble the information obtained from all experimental techniques employed to reach a general conclusion. Tetracaine interacts more with raftlike domains, lidocaine induces stronger modifications on POPC/SM liposomes and the results for propofol are not fully conclusive but it seems to be the least prone to lipid interactions. The results were compared with those obtained with DMPC-containing liposomes, reported in a previous work.

  18. Anesthetic Management of a Child with Mitochondrial Neurogastrointestinal Encephalopathy

    Science.gov (United States)

    Casarez, Vianey Q.; Zavala, Acsa M.; Owusu-Agyemang, Pascal; Hagan, Katherine

    2015-01-01

    Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder associated with deficiency of thymidine phosphorylase (TP). Associated manifestations include visual and hearing impairments, peripheral neuropathies, leukoencephalopathy, and malnutrition from concomitant gastrointestinal dysmotility and pseudoobstruction. Given the altered metabolic state in these patients, specific consideration of medication selection is advised. This case report will describe the anesthetic management used in a 10-year-old girl with MNGIE. She had multiple anesthetics while undergoing allogeneic hematopoietic stem cell transplantation. This case report will discuss the successful repeated use of the same anesthetic in this pediatric patient, with the avoidance of volatile anesthetic agents, propofol, and muscle relaxant. PMID:26124966

  19. Anesthetic Management of a Child with Mitochondrial Neurogastrointestinal Encephalopathy

    Directory of Open Access Journals (Sweden)

    Vianey Q. Casarez

    2015-01-01

    Full Text Available Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE is an autosomal recessive disorder associated with deficiency of thymidine phosphorylase (TP. Associated manifestations include visual and hearing impairments, peripheral neuropathies, leukoencephalopathy, and malnutrition from concomitant gastrointestinal dysmotility and pseudoobstruction. Given the altered metabolic state in these patients, specific consideration of medication selection is advised. This case report will describe the anesthetic management used in a 10-year-old girl with MNGIE. She had multiple anesthetics while undergoing allogeneic hematopoietic stem cell transplantation. This case report will discuss the successful repeated use of the same anesthetic in this pediatric patient, with the avoidance of volatile anesthetic agents, propofol, and muscle relaxant.

  20. Study on the anesthetic effect of combined intravenous-inhalation general anesthesia under nasopharyngeal airway-mask spontaneous breathing for laparoscopic inguinal hernia surgery in children

    Institute of Scientific and Technical Information of China (English)

    Jing Liu

    2016-01-01

    Objective:To analyze the anesthetic effect of combined intravenous-inhalation general anesthesia under nasopharyngeal airway-mask spontaneous breathing for laparoscopic inguinal hernia surgery in children.Methods:A total of118 cases of children with inguinal hernia who received laparoscopic surgery in our hospital from August 2012 to August 2014 were enrolled as research subjects and randomly divided into observation group 59 cases and control group 59 cases. Control group received conventional tracheal intubation intravenous general anesthesia, observation group received combined intravenous-inhalation general anesthesia under nasopharyngeal airway-mask spontaneous breathing, and then differences in respiratory and circulatory indicators, awareness-related indicators, G-6PD, PFK and inflammatory factor levels and oxidative stress levels between two groups were compared.Results:HR and MAP values of observation group at T1 and T2 were lower than those of control group, and SpO2 value was higher than that of control group; intraoperative Ppeak, Pplat, Raw, D(A-a)O2 and RI levels of observation group were lower than those of control group, and levels of Cdyn and OI were higher than those of control group; intraoperative G-6PD, PFK, CRP and IL-6 levels of observation group were lower than those of control group, and IL-10 level was higher than that of control group; intraoperative NO, SOD and GSH levels of observation group were higher than those of control group, and levels of ET-1, CAT and blood glucose were lower than those of control group.Conclusion:Combined intravenous-inhalation general anesthesia under nasopharyngeal airway-mask spontaneous breathing for laparoscopic inguinal hernia surgery in children can effectively stabilize respiratory and circulatory level, reduce intraoperative systemic inflammation and oxidative stress state and contribute to early postoperative rehabilitation.

  1. Anesthetics drug pharmacodynamics.

    Science.gov (United States)

    Bischoff, P; Schneider, G; Kochs, E

    2008-01-01

    Anesthesia cannot be defined in an unambiguous manner. The essential components of general anesthesia are absence of consciousness and pain. This translates into two particular qualities: (1) sedation and hypnosis, i.e., mental blockade and (2) analgesia/antinociception, i.e., sensory blockade. Anesthetic actions on these two subcomponents are difficult to separate. On the one hand, very few anesthetics act exclusively on one of these components. On the other hand, these components are closely related to each other. Unconsciousness prevents (conscious) perception of pain, and nociception may serve as an arousal stimulus and change the level of sedation and hypnosis. The art of anesthesia lies in adequate dosing of drugs to reach both mental and sensory blockade. Drug administration can be based on pharmacokinetic considerations. Pharmacokinetic models allow an estimation of what happens to the administered drug in the body. Models with an effect site compartment may facilitate a tailored administration of anesthetic drugs. Finally, the quantification of pharmacodynamic effects allows a precise titration of drugs. Clinical assessment of mental blockade is often dichotomous, and therefore not very helpful to guide drug administration. Several scoring systems exist, but once consciousness is lost they become less reliable, in particular because reaction to stimuli is assessed, which mixes assessment of mental blockade with assessment of sensory blockade. Clinical assessment of analgesia requires a conscious patient, so antinociception is difficult to measure. Several methods of objective quantification on the basis of electrical brain activity are discussed including EEG and evoked potentials. Despite numerous indexes of the hypnotic component of anesthesia, there is no parameter that unambiguously quantifies the level of mental or sensory blockade.

  2. General anesthetic action at an internal protein site involving the S4-S5 cytoplasmic loop of a neuronal K(+) channel.

    Science.gov (United States)

    Harris, T; Shahidullah, M; Ellingson, J S; Covarrubias, M

    2000-02-18

    The structural bases of general anesthetic action on a neuronal K(+) channel were investigated using the series of homologous 1-alkanols, electrophysiology, and mutational analysis. Domain swapping between dShaw2 (alkanol-sensitive) and hKv3.4 (alkanol-resistant) and site-directed mutagenesis demonstrated that a 13-amino acid cytoplasmic loop (S4-S5) determines the selective inhibition of native dShaw2 channels by 1-alkanols. The S4-S5 loop may contribute to a receptor for both 1-alkanols and the inactivation particle, because the enhanced 1-alkanol sensitivity of hKv3.4 channels hosting S4-S5 mutations correlates directly with disrupted channel inactivation. Evidence of a discrete protein site was also obtained from the analysis of the relationship between potency and alkyl chain length, which begins to level off after 1-hexanol. Rapid application to the cytoplasmic side of inside-out membrane patches shows that the interaction between dShaw2 channels and 1-alkanols equilibrates in 1000-fold slower when the drug is applied externally to outside-out membrane patches. The data strongly favor a mechanism of inhibition involving a discrete internal site for 1-alkanols in dShaw2 K(+) channels. A new working hypothesis proposes that 1-alkanols lock dShaw2 channels in their closed conformation by a direct interaction at a crevice formed by the S4-S5 loop.

  3. Estimating Price Volatility Structure in Iran’s Meat Market: Application of General GARCH Models

    Directory of Open Access Journals (Sweden)

    Z. Rasouli Birami

    2016-10-01

    Full Text Available Introduction: Over the past few years, the price volatility of agricultural products and food markets has attracted attention of many researchers and policy makers. This growing attention was started from the food price crisis in 2007 and 2008 when major agricultural products faced accelerated price increases and then rapidly decreased. This paper focused on the price volatility of major commodities related to three market levels of Iran’s meat market, including hay (the input level, calf and sheep (the wholesale level and beef and mutton (the retail level. In particular, efforts will made to find more appropriate models for explaining the behavior of volatility of the return series and to identify which return series are more volatile. The effects of good and bad news on the volatility of prices in each return series will also be studied. Materials and Methods: Different GARCH type models have been considered the best for modeling volatility of return series. Nonlinear GARCH models were introduced to capture the effect of good and bad news separately. The paper uses some GARCH type models including GARCH, Exponential GARCH (EGARCH, GJR-GARCH, Threshold GARCH (TGARCH, Simple Asymmetric GARCH (SAGARCH, Power GARCH (PGARCH, Non-linear GARCH (NGARCH, Asymmetric Power GARCH (APGARCH and Non-linear Power GARCH (NPGARCH to model the volatility of hay, calf, sheep, beef and mutton return series. The data on hay, calf, sheep, and beef and mutton monthly prices are published by Iran’s livestock support firm. The paper uses monthly data over the sample period of the May 1992 to the March 2014. Results and Discussion: Descriptive statistics of the studied return series show evidence of skewness and kurtosis. The results here show that all the series has fat tails. The significant p-values for the Ljung-Box Q-statistics mean that the auto-correlation exists in the squared residuals. The presence of unit roots in the return series is confirmed by the

  4. The limiting properties of the QMLE in a general class of asymmetric volatility models

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Iglesias, Emma M.

    more flexible representation of the conditional variance function. (2) It is possible to provide a complete characterization of the asymptotic distribution of the QML estimator based on the new class of nonlinear volatility models, something which has proven very difficult even for the traditional...

  5. Anesthetic strategy during endovascular therapy: General anesthesia or conscious sedation? (GOLIATH - General or Local Anesthesia in Intra Arterial Therapy) A single-center randomized trial

    DEFF Research Database (Denmark)

    Simonsen, Claus Z; Sørensen, Leif H; Juul, Niels

    2016-01-01

    RATIONALE: Endovascular therapy after acute ischemic stroke due to large vessel occlusion is now standard of care. There is equipoise as to what kind of anesthesia patients should receive during the procedure. Observational studies suggest that general anesthesia is associated with worse outcomes...... compared to conscious sedation. However, the findings may have been biased. Randomized clinical trials are needed to determine whether the choice of anesthesia may influence outcome. AIM AND HYPOTHESIS: The objective of GOLIATH (General or Local Anestesia in Intra Arterial Therapy) is to examine whether....... Patients with acute ischemic stroke, scheduled for endovascular therapy, are randomized to receive either general anesthesia or conscious sedation. STUDY OUTCOMES: The primary outcome measure is infarct growth after 48-72 h (determined by serial diffusion-weighted magnetic resonance imaging). Secondary...

  6. Anesthetizing animals: Similar to humans yet, peculiar?

    Science.gov (United States)

    Kurdi, Madhuri S; Ramaswamy, Ashwini H

    2015-01-01

    From time immemorial, animals have served as models for humans. Like humans, animals too have to undergo several types of elective and emergency surgeries. Several anesthetic techniques and drugs used in humans are also used in animals. However, unlike humans, the animal kingdom includes a wide variety of species, breeds, and sizes. Different species have variable pharmacological responses, anatomy, temperament, behavior, and lifestyles. The anesthetic techniques and drugs have to suit different species and breeds. Nevertheless, there are several drugs and many peculiar anesthetic techniques used in animals but not in human beings. Keeping this in mind, literature was hand searched and electronically searched using the words "veterinary anesthesia," "anesthetic drugs and techniques in animals" using Google search engine. The interesting information so collected is presented in this article which highlights some challenging and amazing aspects of anesthetizing animals including the preanesthetic assessment, preparation, premedication, monitoring, induction of general anesthesia, intubation, equipment, regional blocks, neuraxial block, and perioperative complications.

  7. Child with aplastic anemia: Anesthetic management

    Directory of Open Access Journals (Sweden)

    Manpreet Kaur

    2012-01-01

    Full Text Available Aplastic anemia is a rare heterogeneous disorder of hematopoietic stem cells causing pancytopenia and marrow hypoplasia with the depletion of all types of blood cells. This results in anemia, neutropenia and thrombocytopenia, which pose a challenge to both surgical and anesthetic management of such cases. We report a child with aplastic anemia who sustained traumatic ulcer on the arm and underwent split-thickness skin grafting under general anesthesia. There are only two case reports on anesthetic considerations in aplastic anemia patients in the literature. The anesthetic management is challenging because of the rarity of the disease, associated pancytopenia and immunosuppression.

  8. Sevoflurane: a new inhalational anesthetic agent.

    Science.gov (United States)

    Wallin, R F; Regan, B M; Napoli, M D; Stern, I J

    1975-01-01

    Laboratory screening of a series of halogenated methyl isopropyl ethers revealed sevoflurane (fluoromethyl-1,1,1,3,3,3,-hexafluroro-2-propyl ether) as a potent nonexplosive inhalational anesthetic agent. Sevoflurance, a pleasant-smelling liquid, boils at 58.5 degrees C at 760 torr and has a vapor pressure of 200 torr at 25 degrees C. It is nonflammable in air and has lower flammability limits of 11 vols percent in O2 and 10 vols percent in N2O. Sevoflurane exhibits limited chemical reactivity in vitro; it is subject to slight but measurable hydrolysis, and reacts with soda lime to form traces of related ethers. It provides rapid anesthetic induction and recovery consistent with its low distribution coefficients (blood:gas, 0.6; corn oil:gas, 41.6; olive oil:gas, 53.4). In dogs, anesthetic concentrations of sevoflurane did not produce spontaneous cardiac arrhythmias and did not sensitize the heart to epinephrine. Electroencephalographic patterns were similar to those observed during anesthesia with halothane. In rats, small increases in the urinary excretion of inorganic fluoride ion occurred during the first 24 hours after anesthesia. Subacute studies in dogs and rats, using closed-circle absorption with soda lime, revealed no toxicologically significant changes in animals anesthetized frequently for 2 weeks. Sevoflurane appears to be a unique volatile anesthetic agent worthy of further study.

  9. Advanced technologies and devices for inhalational anesthetic drug dosing.

    Science.gov (United States)

    Meyer, J-U; Kullik, G; Wruck, N; Kück, K; Manigel, J

    2008-01-01

    Technological advances in micromechanics, optical sensing, and computing have led to innovative and reliable concepts of precise dosing and sensing of modern volatile anesthetics. Mixing of saturated desflurane flow with fresh gas flow (FGF) requires differential pressure sensing between the two circuits for precise delivery. The medical gas xenon is administered most economically in a closed circuit breathing system. Sensing of xenon in the breathing system is achieved with miniaturized and unique gas detector systems. Innovative sensing principles such as thermal conductivity and sound velocity are applied. The combination of direct injection of volatile anesthetics and low-flow in a closed circuit system requires simultaneous sensing of the inhaled and exhaled gas concentrations. When anesthetic conserving devices are used for sedation with volatile anesthetics, regular gas concentration monitoring is advised. High minimal alveolar concentration (MAC) of some anesthetics and low-flow conditions bear the risk of hypoxic gas delivery. Oxygen sensing based on paramagnetic thermal transduction has become the choice when long lifetime and one-time calibration are required. Compact design of beam splitters, infrared filters, and detectors have led to multiple spectra detector systems that fit in thimble-sized housings. Response times of less than 500 ms allow systems to distinguish inhaled from exhaled gas concentrations. The compact gas detector systems are a prerequisite to provide "quantitative anesthesia" in closed circuit feedback-controlled breathing systems. Advanced anesthesia devices in closed circuit mode employ multiple feedback systems. Multiple feedbacks include controls of volume, concentrations of anesthetics, and concentration of oxygen with a corresponding safety system. In the ideal case, the feedback system delivers precisely what the patient is consuming. In this chapter, we introduce advanced technologies and device concepts for delivering

  10. LOCAL ANESTHETICS IN PATIENTS WITH CARDIOVASCULAR DISEASES.

    Directory of Open Access Journals (Sweden)

    risto Daskalov

    2015-03-01

    Full Text Available A significant problem in the dental medicine is pain alleviation. Many studies in the dental anesthesiology result in the production of new agents for locoregional anesthesia. Objective: This article aim to present the results of the last studies on the effect of the local anesthetics used in the oral surgery on patients with cardiovascular diseases. Material: A general review of the existing literature on the effect of the adrenaline, included as vasoconstrictor in the local anesthetics, used in patients with cardiovascular diseases is made. The benefits of vasoconstrictors for the quality of the anesthetic effect are proven. Conclusion: A small amount of adrenaline in the anesthetic solution does not result in complications development in patients with controlled cardiovascular diseases. Articaine is recommended agent of first choice for local anesthesia in the oral surgery.

  11. Anesthetizing the obese child

    DEFF Research Database (Denmark)

    Mortensen, Anette; Lenz, Katja; Abildstrøm, Hanne

    2011-01-01

    The prevalence of childhood obesity is increasing. The focus of this review is the special anesthetic considerations regarding the perioperative management of obese children. With obesity the risk of comorbidity such as asthma, obstructive sleep apnea, hypertension, and diabetes increases....... The obese child has an increased risk of perioperative complications especially related to airway management and ventilation. There is a significantly increased risk of difficult mask ventilation and perioperative desaturation. Furthermore, obesity has an impact on the pharmacokinetics of most anesthetic...

  12. Anesthetics impact the resolution of inflammation.

    Directory of Open Access Journals (Sweden)

    Nan Chiang

    Full Text Available BACKGROUND: Local and volatile anesthetics are widely used for surgery. It is not known whether anesthetics impinge on the orchestrated events in spontaneous resolution of acute inflammation. Here we investigated whether a commonly used local anesthetic (lidocaine and a widely used inhaled anesthetic (isoflurane impact the active process of resolution of inflammation. METHODS AND FINDINGS: Using murine peritonitis induced by zymosan and a systems approach, we report that lidocaine delayed and blocked key events in resolution of inflammation. Lidocaine inhibited both PMN apoptosis and macrophage uptake of apoptotic PMN, events that contributed to impaired PMN removal from exudates and thereby delayed the onset of resolution of acute inflammation and return to homeostasis. Lidocaine did not alter the levels of specific lipid mediators, including pro-inflammatory leukotriene B(4, prostaglandin E(2 and anti-inflammatory lipoxin A(4, in the cell-free peritoneal lavages. Addition of a lipoxin A(4 stable analog, partially rescued lidocaine-delayed resolution of inflammation. To identify protein components underlying lidocaine's actions in resolution, systematic proteomics was carried out using nanospray-liquid chromatography-tandem mass spectrometry. Lidocaine selectively up-regulated pro-inflammatory proteins including S100A8/9 and CRAMP/LL-37, and down-regulated anti-inflammatory and some pro-resolution peptides and proteins including IL-4, IL-13, TGF-â and Galectin-1. In contrast, the volatile anesthetic isoflurane promoted resolution in this system, diminishing the amplitude of PMN infiltration and shortening the resolution interval (Ri approximately 50%. In addition, isoflurane down-regulated a panel of pro-inflammatory chemokines and cytokines, as well as proteins known to be active in cell migration and chemotaxis (i.e., CRAMP and cofilin-1. The distinct impact of lidocaine and isoflurane on selective molecules may underlie their opposite

  13. Lack of effect of flurothyl, a non-anesthetic fluorinated ether, on rat brain synaptic plasma membrane calcium-ATPase.

    Science.gov (United States)

    Horn, J L; Janicki, P K; Franks, J J

    1999-01-01

    Plasma membrane Ca2+-ATPase (PMCA), a regulator of intracellular calcium, is inhibited by volatile anesthetics and by xenon and nitrous oxide. Response of a cellular system to anesthetics, particularly to volatile agents, raises the question of non-specific, even toxic, side effects unrelated to anesthetic action. Compounds with chemical and physical properties similar to halogenated anesthetics, but which lack anesthetic effect, have been used to address this question. We have compared the effects of halothane and flurothyl, a non-anesthetic fluorinated ether, on PMCA Ca2+ transport across isolated brain synaptic plasma membranes (SPM). Flurothyl, at concentrations predicted by the Meyer-Overton curve to range from 0.4 to 2.6 MAC (minimum alveolar concentration), had no significant on PMCA activity. In contrast halothane, 1.3 MAC, reduced Ca2+ transport 30 to 40%. These findings provide further evidence for a specific effect of inhalation anesthetics on neuronal plasma membrane Ca2+-ATPase.

  14. Interaction of anesthetics with neurotransmitter release machinery proteins.

    Science.gov (United States)

    Xie, Zheng; McMillan, Kyle; Pike, Carolyn M; Cahill, Anne L; Herring, Bruce E; Wang, Qiang; Fox, Aaron P

    2013-02-01

    General anesthetics produce anesthesia by depressing central nervous system activity. Activation of inhibitory GABA(A) receptors plays a central role in the action of many clinically relevant general anesthetics. Even so, there is growing evidence that anesthetics can act at a presynaptic locus to inhibit neurotransmitter release. Our own data identified the neurotransmitter release machinery as a target for anesthetic action. In the present study, we sought to examine the site of anesthetic action more closely. Exocytosis was stimulated by directly elevating the intracellular Ca(2+) concentration at neurotransmitter release sites, thereby bypassing anesthetic effects on channels and receptors, allowing anesthetic effects on the neurotransmitter release machinery to be examined in isolation. Three different PC12 cell lines, which had the expression of different release machinery proteins stably suppressed by RNA interference, were used in these studies. Interestingly, there was still significant neurotransmitter release when these knockdown PC12 cells were stimulated. We have previously shown that etomidate, isoflurane, and propofol all inhibited the neurotransmitter release machinery in wild-type PC12 cells. In the present study, we show that knocking down synaptotagmin I completely prevented etomidate from inhibiting neurotransmitter release. Synaptotagmin I knockdown also diminished the inhibition produced by propofol and isoflurane, but the magnitude of the effect was not as large. Knockdown of SNAP-25 and SNAP-23 expression also changed the ability of these three anesthetics to inhibit neurotransmitter release. Our results suggest that general anesthetics inhibit the neurotransmitter release machinery by interacting with multiple SNARE and SNARE-associated proteins.

  15. Medical imaging technology shock and volatility of macro economics: Analysis using a three-sector dynamical stochastic general equilibrium REC model.

    Science.gov (United States)

    Han, Shurong; Huang, Yeqing

    2017-07-07

    The study analysed the medical imaging technology business cycle from 1981 to 2009 and found that the volatility of consumption in Chinese medical imaging business was higher than that of the developed countries. The volatility of gross domestic product (GDP) and the correlation between consumption and GDP is also higher than that of the developed countries. Prior to the early 1990s the volatility of consumption is even higher than GDP. This fact makes it difficult to explain the volatile market using the standard one sector real economic cycle (REC) model. Contrary to the other domestic studies, this study considers a three-sector dynamical stochastic general equilibrium REC model. In this model there are two consumption sectors, whereby one is labour intensive and another is capital intensive. The more capital intensive investment sector only introduces technology shocks in the medical imaging market. Our response functions and Monte-Carlo simulation results show that the model can explain 90% of the volatility of consummation relative to GDP, and explain the correlation between consumption and GDP. The results demonstrated the significant correlation between the technological reform in medical imaging and volatility in the labour market on Chinese macro economy development.

  16. Safety and Efficacy of Volatile Anesthetic Agents Compared With Standard Intravenous Midazolam/Propofol Sedation in Ventilated Critical Care Patients: A Meta-analysis and Systematic Review of Prospective Trials.

    Science.gov (United States)

    Jerath, Angela; Panckhurst, Jonathan; Parotto, Matteo; Lightfoot, Nicholas; Wasowicz, Marcin; Ferguson, Niall D; Steel, Andrew; Beattie, W Scott

    2017-04-01

    Inhalation agents are being used in place of intravenous agents to provide sedation in some intensive care units. We performed a systematic review and meta-analysis of prospective randomized controlled trials, which compared the use of volatile agents versus intravenous midazolam or propofol in critical care units. A search was conducted using MEDLINE (1946-2015), EMBASE (1947-2015), Web of Science index (1900-2015), and Cochrane Central Register of Controlled Trials. Eligible studies included randomized controlled trials comparing inhaled volatile (desflurane, sevoflurane, and isoflurane) sedation to intravenous midazolam or propofol. Primary outcome assessed the effect of volatile-based sedation on extubation times (time between discontinuing sedation and tracheal extubation). Secondary outcomes included time to obey verbal commands, proportion of time spent in target sedation, nausea and vomiting, mortality, length of intensive care unit, and length of hospital stay. Heterogeneity was assessed using the I statistic. Outcomes were assessed using a random or fixed-effects model depending on heterogeneity. Eight trials with 523 patients comparing all volatile agents with intravenous midazolam or propofol showed a reduction in extubation times using volatile agents (difference in means, -52.7 minutes; 95% confidence interval [CI], -75.1 to -30.3; P midazolam (difference in means, -292.2 minutes; 95% CI, -384.4 to -200.1; P < .00001) than propofol (difference in means, -29.1 minutes; 95% CI, -46.7 to -11.4; P = .001). There was no significant difference in time to obey verbal commands, proportion of time spent in target sedation, adverse events, death, or length of hospital stay. Volatile-based sedation demonstrates a reduction in time to extubation, with no increase in short-term adverse outcomes. Marked study heterogeneity was present, and the results show marked positive publication bias. However, a reduction in extubation time was still evident after statistical

  17. A Unitary Anesthetic Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Vedula, L. Sangeetha; Brannigan, Grace; Economou, Nicoleta J.; Xi, Jin; Hall, Michael A.; Liu, Renyu; Rossi, Matthew J.; Dailey, William P.; Grasty, Kimberly C.; Klein, Michael L.; Eckenhoff, Roderic G.; Loll, Patrick J.; (Drexel-MED); (UPENN)

    2009-10-21

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA{sub A} receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  18. A Unitary Anesthetic Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    L Vedula; G Brannigan; N Economou; J Xi; M Hall; R Liu; M Rossi; W Dailey; K Grasty; et. al.

    2011-12-31

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA{sub A} receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  19. A Unitary Anesthetic-Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Vedula, L.; Brannigan, G; Economou, N; Xi, J; Hall, M; Liu, R; Rossi, M; Dailey, W; Grasty, K; et. al.

    2009-01-01

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABAA receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  20. Anesthetic Considerations in a Patient with Myotonic Dystrophy for Hip Labral Repair

    Science.gov (United States)

    Wang, David; Ludwin, Danielle

    2017-01-01

    Myotonic Dystrophy (DM) affects multiple organ systems. Disorders such as hyperthyroidism, progressive musculoskeletal weakness, cardiac dysrhythmias, hypoventilation, and cognitive-behavioral disorders may be present in these patients. Thorough preoperative assessment and anesthetic planning are required to minimize the risk of anesthetic complications. Patients with DM can exhibit exquisite sensitivity to sedatives, neuromuscular blocking agents, and volatile anesthetics, resulting in potential postoperative complications. There is limited literature available on successful anesthetic techniques for the DM patient. We present this case report to add to our current fund of knowledge. PMID:28316843

  1. Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

    Science.gov (United States)

    Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

    2017-02-01

    General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

  2. The effects of anesthetics on cortical spreading depression elicitation and c-fos expression in rats.

    Science.gov (United States)

    Kitahara, Y; Taga, K; Abe, H; Shimoji, K

    2001-01-01

    The effects of anesthetics on the generation of cortical spreading depression (CSD) were investigated. Volatile anesthetics halothane, isoflurane, sevoflurane (0.5, 1.0, and 2.0 MAC), and the intravenous anesthetic pentobarbital were studied. Cortical spreading depression was induced by 3M-KCl applied to a surface of brain cortex for 30 minutes. Direct current (DC) potential was recorded, and the number, amplitude, and duration of CSDs were observed. With increasing concentrations of each volatile anesthetic, there was a dose-related reduction in CSD frequency but not in CSD amplitude. At 2.0 MAC of sevoflurane the suppression of CSD was less than with the other volatile anesthetics. In addition, the influence of anesthetics on expression of c-fos mRNA was investigated. Additional animals anesthetized by isoflurane or sevoflurane were studied. Five CSDs were elicited by electric stimulation (0.5 mV, 1 second) in each animal. In situ hybridization with 35S-labeled oligonucleotides was used to evaluate the level of c-fos mRNA. The expression of c-fos was observed in the hemisphere in which CSD was elicited, but there was no difference in expression of c-fos among the groups. We conclude that volatile anesthetics can induce suppression of CSD elicitation in a dose dependent manner, but that at high concentrations sevoflurane is significantly less effective than other volatile agents. Pentobarbital has the least effect on KCl-induced CSD. These data suggest that the choice of anesthetics can impact the results of studies examining membrane depolarization and the ionic changes initiated by CSD.

  3. Exploring microsolvation of the anesthetic propofol

    NARCIS (Netherlands)

    Leon, I.; Cocinero, E. J.; Millan, J.; Jaeqx, S.; Rijs, A. M.; Lesarri, A.; Castano, F.; Fernandez, J. A.

    2012-01-01

    Propofol (2,6-diisopropylphenol) is a broadly used general anesthetic. By combining spectroscopic techniques such as 1- and 2-color REMPI, UV/UV hole burning, infrared ion-dip spectroscopy (IRIDS) obtained under cooled and isolated conditions with high-level ab initio calculations, detailed

  4. Llama anesthetic programs.

    Science.gov (United States)

    Heath, R B

    1989-03-01

    Llamas are anesthetized conveniently with guaifenesin thiamylal mixes, or, for short periods of time, with xylazine/ketamine. Small individuals must be accurately weighed. Estimating weight without experience is dangerous in this species. The greatest levels of safety and control, especially for critical patients, is afforded by inhalation anesthesia techniques using small animal equipment. All neonates and juveniles can be masked readily but in adults intravenous induction is most satisfactory. Intubation is aided by a long blade laryngoscope. Blood pressure monitoring is best accomplished with an arterial line in the ear artery. However, doppler equipment on the tail or distal leg usually works well.

  5. Anesthetic-Induced Developmental Neurotoxicity

    Institute of Scientific and Technical Information of China (English)

    Jia-RenLiu; Qian Liu; Jing Li; Sulpicio G. Soriano

    2011-01-01

    1 IntroductionMillions of newborn and infants receive anesthetic,sedative and analgesic drugs for surgery and painful procedures on a daily basis.Recent laboratory reports clearly demonstrate that anesthetic and sedative drugs induced both neuroapoptosis and neurocognitive deficits in laboratory models.This issue is of paramount interest to pediatric anesthesiologists and intensivists because it questions the safety of anesthetics used for fetal and neonatal anesthesia[1-2].In an attempt to summarize the rapidly expanding laboratorybased literature on anesthetic-induced developmental neurotoxicity (AIDN),this review will examine published reports on the characterization,mechanisms and alleviation of this phenomenon.

  6. Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory

    Science.gov (United States)

    Keller, John W.; Fabbri, Cindy E.

    2012-01-01

    Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…

  7. Neurotoxicity versus Neuroprotection of Anesthetics: Young Children on the Ropes?

    Science.gov (United States)

    Eizaga Rebollar, Ramón; García Palacios, María V; Morales Guerrero, Javier; Torres Morera, Luis M

    2017-08-01

    Normal brain development in young children depends on a balance between excitation and inhibition of neurons, and alterations to this balance may cause apoptosis. During the perioperative period, both surgical stimuli and anesthetics can induce neurotoxicity. This article attempts to expand the perspective of a topical issue-anesthetic-induced neurotoxicity-by also considering the protective effect of general anesthetics against surgery-induced neurotoxicity, all of which may generate some controversy in the current literature. The "new" major factor influencing neurotoxicity-nociceptive stimulus-is discussed together with other factors to develop clinical and research strategies to obtain a balance between neurotoxicity and neuroprotection.

  8. Child with aplastic anemia: Anesthetic management

    OpenAIRE

    Manpreet Kaur; Babita Gupta; Aanchal Sharma; Sanjeev Sharma

    2012-01-01

    Aplastic anemia is a rare heterogeneous disorder of hematopoietic stem cells causing pancytopenia and marrow hypoplasia with the depletion of all types of blood cells. This results in anemia, neutropenia and thrombocytopenia, which pose a challenge to both surgical and anesthetic management of such cases. We report a child with aplastic anemia who sustained traumatic ulcer on the arm and underwent split-thickness skin grafting under general anesthesia. There are only two case reports on anest...

  9. Dexmedetomidine as the primary anesthetic agent during cardiac surgery in an infant with a family history of malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Aymen Naguib

    2011-01-01

    Full Text Available Malignant hyperthermia (MH is an acute hypermetabolic crisis triggered in susceptible patients by the administration of succinylcholine or a volatile anesthetic agent. When providing anesthetic care for MH-susceptible agents, a total intravenous anesthetic (TIVA technique is frequently chosen. When choosing the components for TIVA, several options exist including the combination of propofol or dexmedetomidine with an opioid. We present our experience with the use of dexmedetomidine as a key component of the anesthetic regimen in a 5-month-old infant with a family history of MH. Previous reports of the use of dexmedetomidine in MH-susceptible patients are reviewed and its benefits in such patients discussed.

  10. 抗NMDA受体脑炎患者卵巢囊肿剔除术的麻醉处理%Anesthetic management for ovarian cystectomy in patients with anti-N-methyl-D-aspartate receptor encephalitis undergoing general anesthesia

    Institute of Scientific and Technical Information of China (English)

    陈雯; 桑诺尔; 罗爱伦; 黄宇光

    2014-01-01

    Objective Anti-N-methyl-D-Aspartate (NMDA) receptor encephalitis is a rare disease,recently described as autoimmune disorder of paraneoplastic limbic encephalitis,which is related to the NMDA receptor antibodies and frequently develops in young women with ovarian teratoma.The disease is usually accompanied by symptoms of psychosis and abnormal behaviors,autonomic nervous system dysfunction,central hypoventilation,and hyperthermia.During induction and maintenance of general anesthesia,we should be aware of adverse reactions such as cardiovascular events,hyperthermia and respiratory insufficiency.In order to maintain vital signs stable,pharmacological agents including vasopressors,β-blockers,antihypertensives,and anticholinergics should be prepared before the surgery.Invasive monitoring for blood pressure can be set if necessary.This study described the method for anesthetic management of 3 patients with anti-NMDA receptor encephalitis undergoing resection of ovarian teratoma under general anesthesia.Preoperative treatment included antipsychotic,anti-infective and immune therapy.General anesthesia was induced with propofol,rocuronium,fentanyl and midazolam to facilitate tracheal intubation and was maintained with inhalation of sevoflurane (mixed with oxygen and air) and intermittent iv boluses of fentanyl and rocuronium during the surgery.All the drugs mentioned above had no interaction or had slight indirect action on anti-NMDA receptors to avoid NMDA-related adverse reactions.In conclusion,the adequate preparation for the surgery should be done in this kind of patients,we should avoid using anesthetics having NMDA receptor antagonism (such as ketamine,N2O,methadone,dextromethorphan,phencyclidine) or other anesthetics acting indirectly (such as pentobarbital) on the NMDA receptors during anesthetic management in the patients with anti-NMDA receptor encephalitis.%目的 抗NMDA受体脑炎是一种与抗NMDA受体抗体相关的、自身免疫性副肿瘤边缘叶

  11. Stock markets liberalization affects volatility?

    OpenAIRE

    Ioan Alin NISTOR; Maria-Lenuţa CIUPAC-ULICI; GHERMAN Mircea-Cristian

    2012-01-01

    Regarding the impact of liberalization, the results show that, in general, market opening is accompanied by a significant increase in market volatility. In particular, volatility tends to decrease due to large capital inflows and domestic growth.The study analyzes the impact of stock market liberalization on volatility in six emerging stock markets by using GARCH methodology. Theory on the effects of financial liberalization on volatility has been ambiguous, and empirical work has yielded con...

  12. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  13. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity...

  14. Volatile Metabolites

    Directory of Open Access Journals (Sweden)

    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  15. Detecting The Expected Rate of Return Volatility of Financing Instruments of Indonesian Islamic Banking through GARCH Modeling (Generalized Autoregressive Conditional Heteroscedasticity

    Directory of Open Access Journals (Sweden)

    Nurul Huda

    2015-04-01

    Full Text Available Objective - Islamic banks are banks which its activities, both fund raising and funds distribution are on the basis of Islamic principles, namely buying and selling and profit sharing. Islamic banking is aimed at supporting the implementation of national development in order to improve justice, togetherness, and equitable distribution of welfare. In pursuit of supporting the implementation of national development, Islamic banking often faced stability problems of financing instruments being operated. In this case, it is measured by the gap between the actual rate of return and the expected rate of return. The individual actual RoR of this instrument will generate an expected rate of return. This raises the gap or difference between the actual rate of return and the expected rate of return of individual instruments, which in this case is called the abnormal rate of return. The stability of abnormal rate of return of individual instruments is certainly influenced by the stability of the expected rate of return. Expected rate of return has a volatility or fluctuation levels for each financing instrument. It is also a key element or material basis for the establishment of a variance of individual instruments. Variance in this case indicates the level of uncertainty of the rate of return. Individual variance is the origin of the instrument base for variance in the portfolio finance that further a portfolio analysis. So, this paper is going to analyze the level of expected RoR volatility as an initial step to see and predict the stability of the fluctuations in the rate of return of Indonesian Islamic financing instruments.Methods – Probability of Occurence, Expected Rate of Return (RoR and GARCH (Generalized Autoregressive Conditional Heteroscedasticity.Results - The expected RoR volatility of the murabaha and istishna financing instruments tend to be more volatile than expected RoR volatility of musharaka and qardh financing instruments

  16. Water solvent and local anesthetics: A computational study

    Science.gov (United States)

    Bernardi, R. C.; Gomes, D. E. B.; Pascutti, P. G.; Ito, A. S.; Taft, C. A.; Ota, A. T.

    There are various experimental studies regarding the toxicity and the time of action of local anesthetics, which contain general insights about their pharmacological and physicochemical properties. Although a detailed microscopic analysis of the local anesthetics would contribute to understanding these properties, there are relatively few theoretical studies about these molecules. In this article, we present the results from calculations performed for three local anesthetics: tetracaine, procaine, and lidocaine, both in their charged and uncharged forms, in aqueous environment. We have used the density functional theory and molecular dynamics simulations to study the structural characteristics of these compounds. The radial distribution function g(r) was used to examine the structure of water molecules surrounding different regions of the local anesthetics. We demonstrated the nonhomogeneous character of the anesthetics with respect to their affinity to water solvent molecules as well as the modifications in their affinity to water caused by changes in their charge state. We also observed that the biological potency of the anesthetics is more related to the behavior of specific groups within the molecule, which are responsible for the interaction with the lipid phase of membranes, rather than the general properties of the molecule as a whole.

  17. [Evoked potentials and inhalation anesthetics].

    Science.gov (United States)

    Thiel, A; Russ, W; Hempelmann, G

    1988-01-01

    Intraoperative monitoring of evoked potentials can be affected by various factors including volatile anaesthetics. These effects have to be considered in order to give correct interpretations of the obtained data. Visual evoked potentials (VEP) and auditory evoked potentials (AEP) will show strong alterations under general anaesthesia whereas brainstem auditory evoked potentials (BAEP) are slightly affected. The effects of nitrous oxide, halothane, enflurane, and isoflurane on somatosensory evoked potentials (SEP) after median nerve stimulation were studied in 35 healthy adult patients. pCO2 and tympanic membrane temperature were held constant. Simultaneous cervical and cortical SEP recording was performed using surface electrodes. After induction of anaesthesia SEP were recorded during normoventilation with 100% oxygen and after inhalation of 66.6% nitrous oxide. 10 patients received halothane at inspired concentrations of 0.5, 1.0, 1.5, and 2.0%. After nitrous oxide had been replaced by oxygen, halothane was reduced in steps of 0.5%. SEP were recorded at the end of each period (15 min). Equipotent doses of enflurane or isoflurane were administered to 15 and 10 patients, respectively. Nitrous oxide depressed early cortical SEP amplitude. Halothane, enflurane, and isoflurane caused dose dependent increases of latencies. Reduction of amplitude was most pronounced with isoflurane. Using high doses of enflurane in oxygen cortical SEP showed unusual high amplitudes associated with marked increases of latencies. Even under high concentrations of volatile anaesthetics cervical SEP were minimally affected. The effects of anaesthetic gases have to be considered when SEP are recorded intraoperatively.

  18. Tracheal extubation in children: halothane versus isoflurane, anesthetized versus awake.

    Science.gov (United States)

    Pounder, D R; Blackstock, D; Steward, D J

    1991-04-01

    The authors compared the incidence of respiratory complications and arterial hemoglobin desaturation during emergence from anesthesia in children whose tracheas were extubated while they were anesthetized or after they were awake and to whom halothane or isoflurane had been administered. One hundred children 1-4 yr of age undergoing minor urologic surgery were studied. After a standard induction technique, patients were randomized to receive either isoflurane or halothane. In 50 patients tracheal extubation was performed while they were breathing 2 MAC of either halothane or isoflurane in 100% oxygen. The remaining 50 patients received 2 MAC (volatile agent plus nitrous oxide) during the operation, but tracheal extubation was delayed until they were awake. A blinded observer recorded the incidence of respiratory complications and continuously measured hemoglobin saturation for 15 min after extubation. When tracheal extubation occurred in deeply anesthetized patients, no differences were found between the two volatile agents. When tracheal extubation of awake patients was performed, the use of isoflurane was associated with more episodes of coughing and airway obstruction than was halothane (P less than 0.05). Awake tracheal extubation following either agent was associated with significantly more episodes of hemoglobin desaturation than was tracheal extubation while anesthetized.

  19. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  20. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation st...

  1. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  2. PERTURBATION OF VOLTAGE-SENSITIVE CALCIUM FUNCTION IN PHEOCHROMOCYTOMA CELLS BY VOLATILE ORGANIC SOLVENTS.

    Science.gov (United States)

    Volatile organic solvents such as toluene (TOL) and trichloroethylene perturb nervous system function and share characteristic effects with other central nervous system depressants such as anesthetic gasses, ethanol, benzodiazepines and barbiturates. Recently, mechanistic studies...

  3. Anesthetic Maintenance of Thyroid Surgery

    Directory of Open Access Journals (Sweden)

    A. A. Negovsky

    2008-01-01

    Full Text Available Thyroid diseases are most common in endocrinology. Thyrotoxicosis induces dysfunction of virtually all organs and systems, the blood circulatory system being subjected to considerable changes. Cardiovascular diseases affect not only the quality of life in a patient, but significantly increase a risk from surgery that is the only radical treatment. For this reason, most authors consider thyrotoxicosis to be a contraindication to elective surgical intervention. At the same time it is known that drug compensation of thyrotoxicosis may be attained in not all patients. In this case, the results of treatment and a patient’s safety during surgery depend on the type and quality of anesthetic protection. The capabilities of anesthetic maintenance of thyroid surgery have recently expanded substantially. The paper deals with the preparation of patients with thyrotoxicosis for surgical intervention and the perioperative management of these patients. Key words: thyroid, toxic goiter, thyrotoxicosis, premedication, anesthetic mode, sevoflurane, xenon.

  4. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  5. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  6. The thermodynamics of general and local anesthesia

    CERN Document Server

    Graesboll, Kaare; Heimburg, Thomas

    2014-01-01

    General anesthetics are known to cause depression of the freezing point of transitions in biomembranes. This is a consequence of ideal mixing of the anesthetic drugs in the membrane fluid phase and exclusion from the solid phase. Such a generic law provides physical justification of the famous Meyer-Overton rule. We show here that general anesthetics, barbiturates and local anesthetics all display the same effect on melting transitions. Their effect is reversed by hydrostatic pressure. Thus, the thermodynamic behavior of local anesthetics is very similar to that of general anesthetics. We present a detailed thermodynamic analysis of heat capacity profiles of membranes in the presence of anesthetics. This analysis is able to describe experimentally observed calorimetric profiles and permits prediction of the anesthetic features of arbitrary molecules. In addition, we discuss the thermodynamic origin of the cutoff-effect of long-chain alcohols and the additivity of the effect of general and local anesthetics.

  7. Modeling the Volatility in Global Fertilizer Prices

    NARCIS (Netherlands)

    P-Y. Chen (Ping-Yu); C-L. Chang (Chia-Lin); C-C. Chen (Chi-Chung); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe main purpose of this paper is to estimate the volatility in global fertilizer prices. The endogenous structural breakpoint unit root test and alternative volatility models, including the generalized autoregressive conditional heteroskedasticity (GARCH) model, Exponential GARCH (EGARC

  8. Scientometrics of anesthetic drugs and their techniques of administration, 1984–2013

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2014-12-01

    Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthetic drugs over the past 30 years using scientometric indices: popularity indices (general and specific, representing the proportion of articles on a drug relative to all articles in the field of anesthetics (general index or the subfield of a specific class of anesthetics (specific index; index of change, representing the degree of growth in publications on a topic from one period to the next; index of expectations, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed; and index of ultimate success, representing a publication outcome when a new drug takes the place of a common drug previously used for the same purpose. Publications on 58 topics were assessed during six 5-year periods from 1984 to 2013. Our analysis showed that during 2009–2013, out of seven anesthetics with a high general popularity index (≥2.0, only two were introduced after 1980, ie, the inhaled anesthetic sevoflurane and the local anesthetic ropivacaine; however, only sevoflurane had a high index of expectations (12.1. Among anesthetic adjuncts, in 2009–2013, only one agent, sugammadex, had both an extremely high index of change (>100 and a high index of expectations (25.0, reflecting the novelty of its mechanism of action. The index of ultimate success was positive with three anesthetics, ie, lidocaine, isoflurane, and propofol, all of which were introduced much longer than 30 years ago. For the past 30 years, there were no new anesthetics that have produced changes in scientometric indices indicating real progress. Keywords: anesthetics, anesthetic adjuvants, mortality, safety margins, therapeutic indices

  9. Effect of some anesthetics on memory and exploration.

    Science.gov (United States)

    Valzelli, L; Kozak, W; Skorupska, M

    1988-04-01

    A light ether anesthesia in laboratory mice resulted in the complete drop of their memory retrieval to zero for more than three days after the administration. On the contrary, mice that underwent the exploration test after the light ether anesthesia performed as expected, confirming that impairment of memory does not necessarily reflect on exploratory performance. The effect of some anesthetic drugs was then studied on memory retrieval and exploratory behavior. Within this general framework, the anesthetics here studied all worsen memory retrieval, however without inducing clear and long-lasting amnesic effect comparable to that exerted by ether anesthesia. Contrarily, the classically amnesic drug scopolamine, orally administered, enhances memory retrieval and improves exploration.

  10. Anesthetic management of a horse with traumatic pneumothorax

    OpenAIRE

    Chesnel, Maud-Aline; Aprea, Francesco; Clutton, R. Eddie

    2012-01-01

    A traumatic pneumothorax and severe hemorrhage were present in a mare with a large thoracic wall defect, lung perforation, and multiple rib fractures. General anesthesia was induced to allow surgical exploration. We describe the anesthetic technique, and discuss the management of the ventilatory, hemodynamic, and metabolic disturbances encountered.

  11. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  12. Volatility Risk

    OpenAIRE

    Zhiguang Wang

    2009-01-01

    Classical capital asset pricing theory tells us that riskaverse investors would require higher returns to compensate for higher risk on an investment. One type of risk is price (return) risk, which reflects uncertainty in the price level and is measured by the volatility (standard deviation) of asset returns. Volatility itself is also known to be random and hence is perceived as another type of risk. Investors can bear price risk in exchange for a higher return. But are investors willing to p...

  13. Genotoxicity of Anesthetics Evaluated In Vivo (Animals)

    Science.gov (United States)

    Braz, Mariana G.; Karahalil, Bensu

    2015-01-01

    The anesthesia has been improved all over the years. However, it can have impact on health, in both patients and animals anesthetized, as well as professionals exposed to inhaled anesthetics. There is continuing effort to understand the possible effects of anesthetics at molecular levels. Knowing the effects of anesthetic agents on genetic material could be a valuable basic support to better understand the possible mechanisms of these agents. Thus, the purpose of this review is to provide an overview on the genotoxic potential, evaluated in animal models, of many anesthetics that have already been used and those currently used in anesthesia. PMID:26199936

  14. 全麻中不同插管方式对麻醉并发症的影响%Effects of Different Endotracheal Intubation on General Anesthesia on Anesthetic Complications

    Institute of Scientific and Technical Information of China (English)

    马先春; 厉宝书; 刘静

    2012-01-01

      目的探讨喉罩(LM)及气管插管(EI)在全麻(GA)中对血流动力学及麻醉并发症的影响.方法选取我院近2年来腹腔镜胆囊切除术(LC)患者68例,随机分为 A、B 两组,各组34例,A 组采用 LMA,B 组采用 EIA,比较两组麻醉对血流动力学及术后并发症的影响.结果 A 组置管时、拔管时血流动力学较 B 组稳定,A 组术后麻醉并发症少于 B 组,差异有统计学意义(P<0.05).结论 LC 中采用LMA 安全性高,不增加不良反应.%  Objective To study the effects of GA using the LM and EI on hemodynamic stability and anesthetic complications. Method Select the past two years in our hospital,68 cases of LC patients, were randomly divided into A and B groups, each 34, A group using the LMA, B group using EIA. The two groups were compared anesthetic effect. Results A group LMA insertion,5min after LMA insertion, removal of LMA, A group of blood flow dynamics than in group B stable, Anesthetic complications after surgery, group A than group B decreased,the difference was statistically significant (P<0.05). Conclusion LC using the LMA safe, without increasing adverse events.

  15. A 3D general circulation model for Pluto and Triton with fixed volatile abundance and simplified surface forcing

    CERN Document Server

    Zalucha, Angela

    2012-01-01

    We present a 3D general circulation model of Pluto and Triton's atmospheres, which uses radiative-conductive-convective forcing. In both the Pluto and Triton models, an easterly (prograde) jet is present at the equator with a maximum magnitude of 10-12 m/s and 4 m/s, respectively. Neither atmosphere shows any significant overturning circulation in the meridional and vertical directions. Rather, it is horizontal motions (mean circulation and transient waves) that transport heat meridionally at a magnitude of 1 and 3 x 10^7 W at Pluto's autumn equinox and winter solstice, respectively (seasons referenced to the Northern Hemisphere). The meridional and dayside-nightside temperature contrast is small (<5 K). We find that the lack of vertical motion can be explained on Pluto by the strong temperature inversion in the lower atmosphere. The height of the Voyager 2 plumes on Triton can be explained by the dynamical properties of the lower atmosphere alone (i.e., strong wind shear) and does not require a thermally ...

  16. Anesthetic Related Advances with Cyclodextrins

    OpenAIRE

    Mark Welliver; John P. McDonough

    2007-01-01

    Cyclodextrins encapsulate and electrostatically bind to lipophilic molecules. The exterior of cyclodextrins are water-soluble and maintain aqueous solubility despite encapsulation of non-aqueous soluble molecules. This unique ability to encapsulate lipophilic molecules and maintain water solubility confers numerous pharmacologic advantages for both drug delivery and removal. Cyclodextrins, a component part of supramolecular chemistry, may be in its infancy of anesthetic application but recent...

  17. Insight into the modulation of Shaw2 Kv channels by general anesthetics: structural and functional studies of S4-S5 linker and S6 C-terminal peptides in micelles by NMR.

    Science.gov (United States)

    Zhang, Jin; Qu, Xiaoguang; Covarrubias, Manuel; Germann, Markus W

    2013-02-01

    The modulation of the Drosophila Shaw2 Kv channel by 1-alkanols and inhaled anesthetics is correlated with the involvement of the S4-S5 linker and C-terminus of S6, and consistent with stabilization of the channel's closed state. Structural analysis of peptides from S4-S5 (L45) and S6 (S6c), by nuclear magnetic resonance and circular dichroism spectroscopy supports that an α-helical conformation was adopted by L45, while S6c was only in an unstable/dynamic partially folded α-helix in dodecylphosphocholine micelles. Solvent accessibility and paramagnetic probing of L45 revealed that L45 lies parallel to the surface of micelles with charged and polar residues pointing towards the solution while hydrophobic residues are buried inside the micelles. Chemical shift perturbation introduced by 1-butanol on residues Gln320, Thr321, Phe322 and Arg323 of L45, as well as Thr423 and Gln424 of S6c indicates possible anesthetic binding sites on these two important components in the channel activation apparatus. Diffusion measurements confirmed the association of L45, S6c and 1-butanol with micelles which suggests the capability of 1-butanol to influence a possible interaction of L45 and S6c in the micelle environment.

  18. Costs of anesthetics and other drugs in anesthesia

    Directory of Open Access Journals (Sweden)

    Majstorović Branislava M.

    2012-01-01

    Full Text Available Introduction. Drugs are real and transparent costs of treatment, which are subject to constant monitoring and changes. The study was aimed at measuring and analyzing consumption of anesthetics and other drugs in anesthesia in the Clinical Centre of Serbia. Material and Methods. This paper is part of a five-year (2005-2009, academic, pharmacoeconomic retrospective-prospective study (the 4th phase. We calculated the costs of anesthetics and other drugs in all anesthetized patients at the Institute of Anesthesia and Reanimation, Clinical Center of Serbia in 2006. The data, obtained from the Clinical Centre of Serbia Database, were analyzed by descriptive statistical methods using computer program Microsoft Office Excel 2003 and the Statistical Package for the Social Sciences (SPSS for Windows. Results. The amount of money spent for the application of 33,187 general and 16,394 local anesthesia and 20,614 anesthesiology procedures was 83,322,046.36 RSD (Euros 1,054,705.4, which was 5.93% of the funds allocated for all drugs used at the Clinical Center of Serbia. Of the total fund for drugs, 57.8% was spent for anesthetics (local anesthetics 1.2% and muscle relaxants, whereas 42.2% was spent for other drugs in anesthesia. The highest amount was spent at the Emergency Center (35.8%, then at the Cardio-surgery (11.9% and the Neurosurgery (10.9% because of the large number and length of surgical interventions. Conclusion. There is no space for rationalizing the costs of anesthetics and other drugs in anesthesia.

  19. Stochastic volatility selected readings

    CERN Document Server

    Shephard, Neil

    2005-01-01

    Neil Shephard has brought together a set of classic and central papers that have contributed to our understanding of financial volatility. They cover stocks, bonds and currencies and range from 1973 up to 2001. Shephard, a leading researcher in the field, provides a substantial introduction in which he discusses all major issues involved. General Introduction N. Shephard. Part I: Model Building. 1. A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices, (P. K. Clark). 2. Financial Returns Modelled by the Product of Two Stochastic Processes: A Study of Daily Sugar Prices, 1961-7, S. J. Taylor. 3. The Behavior of Random Variables with Nonstationary Variance and the Distribution of Security Prices, B. Rosenberg. 4. The Pricing of Options on Assets with Stochastic Volatilities, J. Hull and A. White. 5. The Dynamics of Exchange Rate Volatility: A Multivariate Latent Factor ARCH Model, F. X. Diebold and M. Nerlove. 6. Multivariate Stochastic Variance Models. 7. Stochastic Autoregressive...

  20. The Role of Dendritic Signaling in the Anesthetic Suppression of Consciousness

    National Research Council Canada - National Science Library

    Meyer, Kaspar

    2015-01-01

    Despite considerable progress in the identification of the molecular targets of general anesthetics, it remains unclear how these drugs affect the brain at the systems level to suppress consciousness...

  1. Anesthetic gases and global warming: Potentials, prevention and future of anesthesia.

    Science.gov (United States)

    Gadani, Hina; Vyas, Arun

    2011-01-01

    Global warming refers to an average increase in the earth's temperature, which in turn causes changes in climate. A warmer earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. Greenhouse gases make the earth warmer by trapping energy inside the atmosphere. Greenhouse gases are any gas that absorbs infrared radiation in the atmosphere and include: water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs). Hazardous chemicals enter the air we breathe as a result of dozens of activities carried out during a typical day at a healthcare facility like processing lab samples, burning fossil fuels etc. We sometimes forget that anesthetic agents are also greenhouse gases (GHGs). Anesthetic agents used today are volatile halogenated ethers and the common carrier gas nitrous oxide known to be aggressive GHGs. With less than 5% of the total delivered halogenated anesthetic being metabolized by the patient, the vast majority of the anesthetic is routinely vented to the atmosphere through the operating room scavenging system. The global warming potential (GWP) of a halogenated anesthetic is up to 2,000 times greater than CO2. Global warming potentials are used to compare the strength of different GHGs to trap heat in the atmosphere relative to that of CO2. Here we discuss about the GWP of anesthetic gases, preventive measures to decrease the global warming effects of anesthetic gases and Xenon, a newer anesthetic gas for the future of anesthesia.

  2. The january effect across volatility regimes

    OpenAIRE

    Agnani, Betty; Aray, Henry

    2007-01-01

    Using a Markov regime switching model, this article presents evidence on the well-known January effect on stock returns. The specification allows a distinction to be drawn between two regimes, one with high volatility and other with low volatility. We obtain a time-varying January effect that is, in general, positive and significant in both volatility regimes. However, this effect is larger in the high volatility regime. In sharp contrast with most previous literature we find two major result...

  3. Anesthetic management of transcatheter aortic valve implantation

    Directory of Open Access Journals (Sweden)

    Annalisa Franco

    2012-01-01

    Full Text Available Transcatheter aortic valve implantation (TAVI is an emergent technique for high-risk patients with aortic stenosis. TAVI poses significant challenges about its management because of the procedure itself and the population who undergo the implantation. Two devices are currently available and marketed in Europe and several other technologies are being developed. The retrograde transfemoral approach is the most popular procedure; nevertheless, it may not be feasible in patients with significant aortic or ileo-femoral arterial disease. Alternatives include a transaxillary approach, transapical approach, open surgical access to the retroperitoneal iliac artery and the ascending aorta. A complementary approach using both devices and alternative routes tailored to the anatomy and the comorbidities of the single patient is a main component for the successful implementation of a TAVI program. Anesthetic strategies vary in different centers. Local anesthesia or general anesthesia are both valid alternatives and can be applied according to the patient′s characteristics and procedural instances. General anesthesia offers many advantages, mainly regarding the possibility of an early diagnosis and treatment of possible complications through the use of transesophageal echocardiography. However, after the initial experiences, many groups began to employ, routinely, sedation plus local anesthesia for TAVI, and their procedural and periprocedural success demonstrates that it is feasible. TAVI is burdened with potential important complications: vascular injuries, arrhythmias, renal impairment, neurological complications, cardiac tamponade, prosthesis malpositioning and embolization and left main coronary artery occlusion. The aim of this work is to review the anesthetic management of TAVI based on the available literature.

  4. [Anesthetic Management of Three Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy].

    Science.gov (United States)

    Maruyama, Naoko; Wakimoto, Mayuko; Inamori, Noriko; Nishimura, Shinya; Mori, Takahiko

    2015-08-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronically progressing or relapsing disease caused by immune-mediated peripheral neuropathy. We report the anesthetic management of three CIDP patients who underwent elective orthopedic surgeries. Owing to the risk of neuraxial anesthetics triggering demyelination, general anesthesia was selected to avoid epidural or spinal anesthesia or other neuraxial blockade. It was also judged prudent to avoid prolonged perioperative immobilization, which might compress vulnerable peripheral nerves. For Patient 1, general anesthesia was induced with propofol, remifentanil, and sevoflurane, and was maintained with sevoflurane and remifentanil. For Patients 2 and 3, general anesthesia was induced and maintained with propofol and remifentanil. For tracheal intubation, under careful monitoring with peripheral nerve stimulators, minimal doses of rocuronium (0.6-0.7 mg x kg(-1)) were administered. When sugammadex was administered to reverse the effect of rocuronium, all patients rapidly regained muscular strength. Postoperative courses were satisfactory without sequelae.

  5. Anesthetic related advances with cyclodextrins.

    Science.gov (United States)

    Welliver, Mark; McDonough, John

    2007-03-02

    Cyclodextrins encapsulate and electrostatically bind to lipophilic molecules. The exterior of cyclodextrins are water-soluble and maintain aqueous solubility despite encapsulation of non-aqueous soluble molecules. This unique ability to encapsulate lipophilic molecules and maintain water solubility confers numerous pharmacologic advantages for both drug delivery and removal. Cyclodextrins, a component part of supramolecular chemistry, may be in its infancy of anesthetic application but recent advances have been described as novel and revolutionary. A review of current research coupled with an understanding of cyclodextrin properties is necessary to fully appreciate the current uses and future potentials of these unique molecules.

  6. Anesthetic Related Advances with Cyclodextrins

    Directory of Open Access Journals (Sweden)

    Mark Welliver

    2007-01-01

    Full Text Available Cyclodextrins encapsulate and electrostatically bind to lipophilic molecules. The exterior of cyclodextrins are water-soluble and maintain aqueous solubility despite encapsulation of non-aqueous soluble molecules. This unique ability to encapsulate lipophilic molecules and maintain water solubility confers numerous pharmacologic advantages for both drug delivery and removal. Cyclodextrins, a component part of supramolecular chemistry, may be in its infancy of anesthetic application but recent advances have been described as novel and revolutionary. A review of current research coupled with an understanding of cyclodextrin properties is necessary to fully appreciate the current uses and future potentials of these unique molecules.

  7. Strabismus complications from local anesthetics.

    Science.gov (United States)

    Guyton, David L

    2008-01-01

    Strabismus developing after retrobulbar or peribulbar anesthesia for both anterior and posterior segment eye surgery may be due to myotoxicity to an extraocular muscle from the local anesthetic agent. Initial paresis often causes diplopia immediately after surgery, but later progressive segmental fibrosis occurs, and/or hypertrophy of the muscle, producing diplopia in the opposite direction from the direction of the initial diplopia. The inferior rectus muscle is most commonly affected. Usually a large recession on an adjustable suture of the involved muscle(s) yields good alignment. Using topical anesthesia or sub-Tenon's anesthesia can avoid this complication.

  8. Anxiety in preoperative anesthetic procedures.

    Science.gov (United States)

    Valenzuela Millán, Jaquelyn; Barrera Serrano, José René; Ornelas Aguirre, José Manuel

    2010-01-01

    Preoperative anxiety is a common and poorly evaluated condition in patients who will undergo an anesthetic and surgical intervention. The objective of this study was to determine the prevalence of anxiety in a group of patients undergoing elective surgery, as assessed by the Amsterdam Anxiety Preoperative and Information (AAPI) scale. We studied 135 patients scheduled for elective surgery applying the AAPI scale 24 h before the surgical procedure to evaluate the presence of anxiety and patient characteristics. A descriptive analysis with mean +/- standard deviation for categorical variables was done. For intragroup differences, chi(2) test was used. Pearson correlation for the association between anxiety and postoperative complications was carried out. A value of p =0.05 was considered significant. One hundred six patients were surgically treated, 88% were female (average age 44 +/- 12 years). Some degree of preoperative anxiety was present in 72 patients (76%; p = 0.001) with a grade point average on the AAPI scale equal to 17 +/- 7 points, of which 95 (70%, OR = 5.08; p = 0.002) were females. Results of this study suggest the presence of high levels of preoperative anxiety in patients scheduled for elective surgery. The origin of the anxiety appears to be related to many factors that can be evaluated in pre-anesthetic consultation. Further study is needed to prevent the presence of this disorder.

  9. Mechanism of Anesthetic Toxicity: Metabolism, Reactive Oxygen Species, Oxidative Stress, and Electron Transfer

    OpenAIRE

    2011-01-01

    There is much literature on the toxic effects of anesthetics. This paper deals with both the volatiles and locals. Adverse effects appear to be multifaceted, with the focus on radicals, oxidative stress (OS), and electron transfer (ET). ET functionalities involved are quinone, iminoquinone, conjugated iminium, and nitrone. The non-ET routes involving radicals and OS apparently pertain to haloalkanes and ethers. Beneficial effects of antioxidants, evidently countering OS, are reported. Knowled...

  10. Prophylactic Antiarrhythmic Effect of Anesthetics at Subanesthetic Concentration on Epinephrine-Induced Arrhythmias in Rats after Brain Death

    Directory of Open Access Journals (Sweden)

    Yuka Miyata

    2015-01-01

    Full Text Available The present study using brain death model of rats was designed to examine whether prophylactic administration of volatile anesthetics and propofol prevent the epinephrine-induced arrhythmias. A Fogarty catheter was placed intracranially for induction of brain death. After brain death, the rats were randomly assigned to five groups: the control group (no anesthetics, the sevoflurane group (0.8%, the isoflurane group (0.5%, the halothane group (0.3%, and the propofol group (195 μg·kg−1·min−1. These anesthetics were about 30% of ED50 of each anesthetic. The arrhythmogenic dose of epinephrine was determined in each anesthetic group. In addition, we examined left ventricular levels of connexin 43 phosphorylation 30 min after administration of each anesthetic with Western blot analysis. The arrhythmogenic dose of epinephrine in the sevoflurane group was significantly higher than that in the control group, while the arrhythmogenic dose of epinephrine in any other anesthetic group was not different. On the other hand, the ratio of phosphorylated-connexin 43/total connexin 43 was also similar among the study groups. Thus, prophylactic administration of subanesthetic dose of sevoflurane is effective in preventing epinephrine-induced arrhythmias after brain death, but phosphorylation of connexin is not involved in the antiarrhythmic property of sevoflurane.

  11. Prophylactic antiarrhythmic effect of anesthetics at subanesthetic concentration on epinephrine-induced arrhythmias in rats after brain death.

    Science.gov (United States)

    Miyata, Yuka; Iwasaki, Mitsuo; Yamanaka, Hiroo; Sato, Masanori; Kamibayashi, Takahiko; Fujino, Yuji; Hayashi, Yukio

    2015-01-01

    The present study using brain death model of rats was designed to examine whether prophylactic administration of volatile anesthetics and propofol prevent the epinephrine-induced arrhythmias. A Fogarty catheter was placed intracranially for induction of brain death. After brain death, the rats were randomly assigned to five groups: the control group (no anesthetics), the sevoflurane group (0.8%), the isoflurane group (0.5%), the halothane group (0.3%), and the propofol group (195 μg·kg(-1) ·min(-1)). These anesthetics were about 30% of ED50 of each anesthetic. The arrhythmogenic dose of epinephrine was determined in each anesthetic group. In addition, we examined left ventricular levels of connexin 43 phosphorylation 30 min after administration of each anesthetic with Western blot analysis. The arrhythmogenic dose of epinephrine in the sevoflurane group was significantly higher than that in the control group, while the arrhythmogenic dose of epinephrine in any other anesthetic group was not different. On the other hand, the ratio of phosphorylated-connexin 43/total connexin 43 was also similar among the study groups. Thus, prophylactic administration of subanesthetic dose of sevoflurane is effective in preventing epinephrine-induced arrhythmias after brain death, but phosphorylation of connexin is not involved in the antiarrhythmic property of sevoflurane.

  12. Anesthetic management of a large mediastinal mass for tracheal stent placement

    Directory of Open Access Journals (Sweden)

    Suman Rajagopalan

    2016-04-01

    Full Text Available ABSTRACT The anesthetic management of patients with large mediastinal masses can be complicated due to the pressure effects of the mass on the airway or major vessels. We present the successful anesthetic management of a 64-year-old female with a large mediastinal mass that encroached on the great vessels and compressed the trachea. A tracheal stent was placed to relieve the tracheal compression under general anesthesia. Spontaneous ventilation was maintained during the perioperative period with the use of a classic laryngeal mask airway. We discuss the utility of laryngeal mask airway for anesthetic management of tracheal stenting in patients with mediastinal masses.

  13. [Anesthetic management of a patient with acromegaly complicated with hyperthyroidism].

    Science.gov (United States)

    Kawakubo, A; Ariyoshi, S; Fukui, S; Shimada, M; Haseba, S; Gotoh, Y

    1989-05-01

    A rare anesthetic experience of a 30-year-old woman with acromegaly complicated with Basedow's disease is reported. After the thyroid function was successfully controlled by drug therapy, resection of pituitary adenoma was performed under general anesthesia. Anesthesia was induced and maintained with NLA. No problem was observed during the operation and postoperative period. Careful attention should be paid to the management of circulation, respiration, metabolism and endocrinium through the perioperative period.

  14. Occupational disease in dentistry and chronic exposure to trace anesthetic gases.

    Science.gov (United States)

    Cohen, E N; Gift, H C; Brown, B W; Greenfield, W; Wu, M L; Jones, T W; Whitcher, C E; Driscoll, E J; Brodsky, J B

    1980-07-01

    A mail survey of 30,650 dentists and 30,547 chairside assistants grouped according to occupational exposure to inhalation anesthetic and sedatives in the dental operatory indicated increased general health problems and reproductive difficulties among respondents exposed to anesthetics. For male dentists who were heavily exposed to anesthetics, the increase in liver disease was 1.7-fold, kidney disease was 1.2-fold, and neurological disease was 1.9-fold. For wives of male dentists who were heavily exposed to anesthetics, the increase in spontaneous abortion rate was 1.5-fold. Among female chairside assistants who were heavily exposed to anesthetics, the increase in liver disease was 1.6-fold, kidney disease was 1.7-fold, and neurological disease was 2.8-fold. The increase in spontaneous abortion rate among assistants who were heavily exposed was 2.3-fold. Cancer rates in women heavily exposed to inhalation anesthetics were increased 1.5-fold but this finding was not statistically significant (P = .06). Separate analysis of the data for disease rates and birth difficulties by type of inhalation anesthetic indicates that in both dentists and chairside assistants chronic exposure to nitrous oxide alone is associated with an increase rate of adverse response.

  15. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  16. Multifractal diffusion entropy analysis on stock volatility in financial markets

    Science.gov (United States)

    Huang, Jingjing; Shang, Pengjian; Zhao, Xiaojun

    2012-11-01

    This paper introduces a generalized diffusion entropy analysis method to analyze long-range correlation then applies this method to stock volatility series. The method uses the techniques of the diffusion process and Rényi entropy to focus on the scaling behaviors of regular volatility and extreme volatility respectively in developed and emerging markets. It successfully distinguishes their differences where regular volatility exhibits long-range persistence while extreme volatility reveals anti-persistence.

  17. Factors associated with anesthetic-related death in dogs and cats in primary care veterinary hospitals.

    Science.gov (United States)

    Matthews, Nora S; Mohn, Thomas J; Yang, Mingyin; Spofford, Nathaniel; Marsh, Alison; Faunt, Karen; Lund, Elizabeth M; Lefebvre, Sandra L

    2017-03-15

    OBJECTIVE To identify risk factors for anesthetic-related death in pet dogs and cats. DESIGN Matched case-control study. ANIMALS 237 dogs and 181 cats. PROCEDURES Electronic medical records from 822 hospitals were examined to identify dogs and cats that underwent general anesthesia (including sedation) or sedation alone and had death attributable to the anesthetic episode ≤ 7 days later (case animals; 115 dogs and 89 cats) or survived > 7 days afterward (control animals [matched by species and hospital]; 122 dogs and 92 cats). Information on patient characteristics and data related to the anesthesia session were extracted. Conditional multivariable logistic regression was performed to identify factors associated with anesthetic-related death for each species. RESULTS The anesthetic-related death rate was higher for cats (11/10,000 anesthetic episodes [0.11%]) than for dogs (5/10,000 anesthetic episodes [0.05%]). Increasing age was associated with increased odds of death for both species, as was undergoing nonelective (vs elective) procedures. Odds of death for dogs were significantly greater when preanesthetic physical examination results were not recorded (vs recorded) or when preanesthetic Hct was outside (vs within) the reference range. Odds of death for cats were greater when intra-anesthesia records for oxygen saturation as measured by pulse oximetry were absent. Underweight dogs had almost 15 times the odds of death as nonunderweight dogs; for cats, odds of death increased with increasing body weight (but not with overweight body condition). CONCLUSIONS AND CLINICAL RELEVANCE Several factors were associated with anesthetic-related death in cats and dogs. This information may be useful for development of strategies to reduce anesthetic-related risks when possible and for education of pet owners about anesthetic risks.

  18. How we recall (or don't): the hippocampal memory machine and anesthetic amnesia.

    Science.gov (United States)

    Perouansky, Misha; Pearce, Robert A

    2011-02-01

    The hippocampal formation occupies a central position for the processing of sensory input into learned, remembered, and consciously retrievable information. The mechanisms by which anesthetic drugs interfere with these processes are now emerging. We review the current understanding of the role of the hippocampal formation in the generation of memory traces and how anesthetics might interfere with its function. Intraoperative amnesia is a desired endpoint of general anesthesia from the perspective of both the patient and the practitioner. "Intraoperative awareness with recall" can result when learning and memory do occur. In addition, anesthetics are capable of inducing a state of "conscious amnesia" that can provide insight into the workings of the brain and might be useful clinically. Anesthesiologists routinely induce the most fascinating pharmacologic effects in existence, the reversible interference of anesthetics with higher cognitive functions. Understanding how the drugs in our custody exert their effects should be our contribution to mankind's universal knowledge base.

  19. Local anesthetics: dentistry's most important drugs.

    Science.gov (United States)

    Malamed, S F

    1994-12-01

    One hundred and fifty years ago, Horace Wells opened the door to local anesthetics. Since then, many advances have been made in pain control. The development of dentistry's most important drugs is highlighted here.

  20. [Facial locoregional anesthetics: principles and precautions].

    Science.gov (United States)

    Lefort, H; Lacroix, G; Cordier, A; Bey, E; Duhamel, P

    2009-12-01

    Facial locoregional anesthetics (ALR) with nervous blocks are simple and reliable to perform, need little technical resources with a very low iatrogenic risk. These blocks allow anesthesia without deforming wound banks using the same materials as usual local anesthetic procedures. Three principal nervous blocks, in a straight line along the vertical pupil axis, allow managing - even extensive - facial wounds. Few side effects may occur which can be easily prevented. It is a good alternative to local anesthetic for the treatment of extensive and deep areas which is performed with a lower number of injections and a high rate of success. These techniques are easy to learn and practise. These anesthetic techniques allow a nice treatment of different kinds of facial wounds from simple suture to flaps.

  1. SYSTEMIC TOXIC REACTIONS TO LOCAL ANESTHETICS

    Science.gov (United States)

    Moore, Daniel C.; Green, John

    1956-01-01

    The topical use of anesthetic agents involves an element of risk. Systemic toxic reactions are rare, but they do occur and may result in death. When a reaction occurs from a topical application, it usually progresses rapidly to respiratory and cardiovascular collapse, and thus therapy must be instituted with more haste to avoid deaths. Fatal systemic toxic reactions from topically administered anesthetic drugs are, in effect, usually not due to well informed use of the drug but to misuse owing to less than complete understanding of absorption. Emphasis is placed on the causes, prophylaxis and treatment of severe systemic toxic reactions which follow the topical application of local anesthetic drugs. If systemic toxic reactions resulting from a safe dose of a local anesthetic agent are correctly treated, there will usually follow an uneventful recovery rather than a catastrophe. PMID:13343009

  2. Effect of buprenorphine on total intravenous anesthetic requirements during spine surgery.

    Science.gov (United States)

    Khelemsky, Yury; Schauer, Jacob; Loo, Nathaniel

    2015-01-01

    Buprenorphine is a partial mu receptor agonist and kappa/delta antagonist commonly used for the treatment of opioid dependence or as an analgesic. It has a long plasma half-life and a high binding affinity for opioid receptors. This affinity is so high, that the effects are not easily antagonized by competitive antagonists, such as naloxone. The high affinity also prevents binding of other opioids, at commonly used clinical doses, to receptor sites - preventing their analgesic and likely minimum alveolar concentration (MAC) reducing benefits. This case report contrasts the anesthetic requirements of a patient undergoing emergency cervical spine surgery while taking buprenorphine with anesthetic requirements of the same patient undergoing a similar procedure after weaning of buprenorphine. Use of intraoperative neurophysiological monitoring prevented use of paralytics and inhalational anesthetics during both cases, therefore total intravenous anesthesia (TIVA) was maintained with propofol and remifentanil infusions. During the initial surgery, intraoperative patient movement could not be controlled with very high doses of propofol and remifentanil. The patient stopped moving in response to surgical stimulation only after the addition of a ketamine. Buprenorphine-naloxone was discontinued postoperatively. Five days later the patient underwent a similar cervical spine surgery. She had drastically reduced anesthetic requirements during this case, suggesting buprenorphine's profound effect on anesthetic dosing. This case report elegantly illustrates that discontinuation of buprenorphine is likely warranted for patients who present for major spine surgery, which necessitates the avoidance of volatile anesthetic and paralytic agents. The addition of ketamine may be necessary in patients maintained on buprenorphine in order to ensure a motionless surgical field.

  3. Anesthetizing animals: Similar to humans yet, peculiar?

    OpenAIRE

    Madhuri S Kurdi; Ramaswamy, Ashwini H

    2015-01-01

    From time immemorial, animals have served as models for humans. Like humans, animals too have to undergo several types of elective and emergency surgeries. Several anesthetic techniques and drugs used in humans are also used in animals. However, unlike humans, the animal kingdom includes a wide variety of species, breeds, and sizes. Different species have variable pharmacological responses, anatomy, temperament, behavior, and lifestyles. The anesthetic techniques and drugs have to suit differ...

  4. Assessment of patient satisfaction with the preoperative anesthetic evaluation

    Directory of Open Access Journals (Sweden)

    Gebremedhn EG

    2014-09-01

    Full Text Available Endale Gebreegziabher Gebremedhn, Vidhya Nagaratnam Department of Anesthesia, School of Medicine, Gondar College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia Background: The evaluation of patient satisfaction is a core aspect of the continuous quality improvement in anesthesia service that can be affected by the preoperative anesthetist visit. This visit enables the anesthetist to know about the patient's general health status and the nature of surgery, to choose the type of anesthesia, and to discuss perioperative complications and their management with the patient. Patients have sometimes complained about the information given during the preoperative anesthetic evaluation in the University of Gondar teaching and referral hospital. The aim of this study was to determine the level of patient satisfaction with the preoperative anesthetist visit. Methods: A cross-sectional study was conducted from February 15 to April 15, 2013. All consecutive elective patients who were operated upon under anesthesia during the study period were interviewed 24 hours after operation. A pretested questionnaire and checklists, which were developed based on the hospital's anesthetic evaluation sheet, were used for data collection. Results: A total of 116 elective patients were operated upon under anesthesia during the study period. Of these, 102 patients were included in our study, with a response rate of 87.9%. Anesthetists introduced themselves to ~24% patients; provided information about anesthesia to ~32%, postoperative complications to ~21%, postoperative analgesia to ~18, and postoperative nausea and vomiting to ~21%; and spent adequate time with ~74%. Patients' questions were answered by the anesthetist in ~65% of cases, and ~65% of patients had reduced anxiety after the anesthetist visit. The patients' overall satisfaction with the preoperative anesthetist visit was ~65%. Conclusion and recommendation: Patient satisfaction with the

  5. Clinical features of pheochromocytoma and perioperative anesthetic management

    Institute of Scientific and Technical Information of China (English)

    罗爱伦; 郭向阳; 易杰; 任洪智; 黄宇光; 叶铁虎

    2003-01-01

    Objective To investigate clinical features of pheochromocytoma and summarize experiences of anesthetic management during the perioperative period. Methods Two hundred and fifty eight patients who were diagnosed with pheochromocytoma in our hospital were reviewed retrospectively for clinical features. According to different preoperative pharmalogical preparations, perioperative mortalities were analyzed in three periods (Period 1: January 1955-December 1975; Period 2: January 1976-December 1994; Period 3: January 1995-July 2001). In Period 3, hemodynamic changes in the patients undergoing different anesthetic methods were analyzed. Results About 5.8% (15/258) of pheochromocytoma was an integral part of multiple endocrine neoplasia (MEN) type Ⅱ or mixed type. Sixty percent (149/249) of the patients who had undergone surgery possessed evidence of catecholamine cardiac toxicity preoperatively. Impaired glucose tolerance was found in 59% (147/249) of the patients before surgery. Perioperative mortality was significantly decreased from 8% (5/60) in Period 1 to 1.2% (1/75) in Period 2 (P<0.01). No perioperative deaths occurred in Period 3. The volume infused during the operation was significantly higher both in the epidural anesthesia group (3474 ml±624 ml, P<0.01) and in the epidural plus general anesthesia group (3654 ml±475 ml, P<0.01) than in the general anesthesia group (2534 ml±512 ml). There were favorable hemodynamic characteristics in patients before removal of the tumor in the epidural anesthesia group and in the epidural plus general anesthesia group, as compared with the general anesthesia group. Conclusions A positive surgical outcome of the excision of pheochromocytoma depends on multiple factors, including careful assessment of potential vital organ damage before surgery and restoration of blood volume by establishing α-blockade preoperatively, meticulous anesthetic management of patients during surgery, and appropriate circulatory support after

  6. Precautionary practices for administering anesthetic gases: A survey of physician anesthesiologists, nurse anesthetists and anesthesiologist assistants.

    Science.gov (United States)

    Boiano, James M; Steege, Andrea L

    2016-10-02

    Scavenging systems and administrative and work practice controls for minimizing occupational exposure to waste anesthetic gases have been recommended for many years. Anesthetic gases and vapors that are released or leak out during medical procedures are considered waste anesthetic gases. To better understand the extent recommended practices are used, the NIOSH Health and Safety Practices Survey of Healthcare Workers was conducted in 2011 among members of professional practice organizations representing anesthesia care providers including physician anesthesiologists, nurse anesthetists, and anesthesiologist assistants. This national survey is the first to examine self-reported use of controls to minimize exposure to waste anesthetic gases among anesthesia care providers. The survey was completed by 1,783 nurse anesthetists, 1,104 physician anesthesiologists, and 100 anesthesiologist assistants who administered inhaled anesthetics in the seven days prior to the survey. Working in hospitals and outpatient surgical centers, respondents most often administered sevoflurane and, to a lesser extent desflurane and isoflurane, in combination with nitrous oxide. Use of scavenging systems was nearly universal, reported by 97% of respondents. However, adherence to other recommended practices was lacking to varying degrees and differed among those administering anesthetics to pediatric (P) or adult (A) patients. Examples of practices which increase exposure risk, expressed as percent of respondents, included: using high (fresh gas) flow anesthesia only (17% P, 6% A), starting anesthetic gas flow before delivery mask or airway mask was applied to patient (35% P; 14% A); not routinely checking anesthesia equipment for leaks (4% P, 5% A), and using a funnel-fill system to fill vaporizers (16%). Respondents also reported that facilities lacked safe handling procedures (19%) and hazard awareness training (18%). Adherence to precautionary work practices was generally highest among

  7. Effects of Injectable Anesthetic Combinations on Left Ventricular Function and Cardiac Morphology in Sprague–Dawley Rats

    OpenAIRE

    Sabatini, Carla F; O'Sullivan, M. Lynne; Valcour, James E.; Sears, William; Johnson, Ron J

    2013-01-01

    Novel anesthetic agents or combinations may provide superior general anesthesia for echocardiography in rodents with the potential for reduced adverse effects. This study sought to characterize the effects of 3 injectable anesthetics on left ventricular (LV) systolic function and cardiac morphology in healthy male and female rats. Rats underwent echocardiographic assessment after general anesthesia via pentobarbital or combinations of ketamine and medetomidine (KME) and ketamine and midazolam...

  8. [Anesthetic management of a pediatric patient with non-Fukuyama type congenital muscular dystrophy].

    Science.gov (United States)

    O'Higashi, T; Kato, S; Shirakami, G; Hirota, K; Suzuki, S; Sasai, S

    1997-01-01

    Non-Fukuyama type congenital muscular dystrophy (n-FCMD), a subtype of progressive muscular dystrophy (PMD), is a very rare autosomal recessive disorder. N-FCMD is characterized by severe and progressive motor weakness and atrophies of proximal muscles during the infant period. A 9-year-old boy with n-FCMD underwent elective surgery for muscle release around the hip joints bilaterally. As many perioperative complications related with volatile anesthetics and muscle relaxants had been reported in the anesthetic management of PMD, these drugs were thought to be contraindicated in patients with n-FCMD. Because n-FCMD seemed to have very similar pathogenesis with PMD, caudal epidural block was chosen, supplemented with the administration of diazepam, pentazocine and nitrous oxide. The operation and anesthesia were conducted uneventfully. No complications occurred postoperatively.

  9. [Awareness with recall during general anesthesia: analysis of 2015 cases].

    Science.gov (United States)

    Shi, Xin; Liu, Xiao-ying; Wang, Wei; Wu, Xin-min

    2006-09-05

    To investigate the incidence of awareness with recall during general anesthesia in elective operation with modern anesthetic methods and to analyze the risk factors thereof. 2025 patients, 1001 males and 1024 females, aged 53 +/- 16, underwent general anesthesia during different kinds of elective operation. Interview was conducted 1 - 3 days postoperatively to survey the incidence of awareness during operation. Two weeks later follow-up was conducted again to know if sequelae existed. Twenty-eight patients (1.4%) were identified as with awareness. Multiple regression analysis showed that awareness during operation was associated with being female (OR = 2.836, 95% CI = 1.81 - 6.810), use of laryngeal mask airway (LMA, OR = 19.609, 95% CI = 3.918 - 98.740), not use volatile anesthetics at a time or continuously during maintenance of anesthesia (OR = 3.084, 95% CI = 1.246 - 7.629), and intra-operative blood pressure fluctuation (OR = 10.430, 95% CI = 3.918 - 27.763), Premedicated patients had lower incidence of awareness during operation (OR = 0.326, 95% CI = 0.110 - 0.965). Twenty-three of the 28 patients with awareness during operation (82%) had auditory perception, 2 (7%) had both auditory and visual perception, 7 felt pain at different degrees, and 10 (36%) felt anxiety during operation. After effects appeared in 6 of the 28 patients (21%). Awareness occurs in some patients undergoing elective operation. Being female, use of LMA, not using volatile anesthetics at a time or continuously during maintenance of anesthesia, and intra-operative blood pressure fluctuation are risk factors. Premedication may help prevent awareness during operation.

  10. 部分全麻药对突触发生期中枢神经系统发育的影响及机制%Effects of some general anesthetics on the development of the central nervous system and their mechanisms

    Institute of Scientific and Technical Information of China (English)

    燕琳

    2012-01-01

    近年的研究表明,在未成熟哺乳动物突触发生期,短暂性拮抗N-甲基-D-天(门)冬氨酸(N-methyl-D-asparate,NMDA)受体或过度激动γ-氨基丁酸A(gamma-amino butyric acid,GABAA)受体可诱发大脑神经细胞的大量凋亡、脊髓凋亡性退变.这些药物主要有全身麻醉药、抗惊厥药及乙醇等.人类突触发生高峰期为妊娠后3个月到出生后3年.妊娠晚期、新生儿及婴幼儿刚好处在这个时间窗,因此该类药物对脑发育的影响成为人们研究的热点,其机制的阐明可能对新生儿、婴幼儿以及孕产妇临床合理用药及新药的开发有指导意义.文中就部分全麻药对突触发生期中枢神经系统发育的影响及机制作一综述.%Recent researches have found that the exposure of the developing mammalians during the period of synaptogenesis to drugs that transiently block N-methyl-D-asparate glutamate receptors or that transiently potentiate gamma-amino butyric acid receptors can trigger widespread apoptotic neurodegeneration in the brains, even in the spinal cords. These drugs include general anesthetics, anticonvulsants, alcohol, etc. The brain growth spurt period, also called synaptogenesis occurs in humans from the third trimester of pregnancy to three years after birth. The time windows include late pregnancy, neonate period and infancy. Therefore, people pay much more attention to the question how these drugs impact the development of the human central nervous system. Elucidation of the mechanisms of some general anesthetics may help the development of new drugs and rational clinical use of the drugs in neonates, in-fants, and pregnant and parturient women.

  11. Recognition of anesthetic barbiturates by a protein binding site: a high resolution structural analysis.

    Directory of Open Access Journals (Sweden)

    Simon Oakley

    Full Text Available Barbiturates potentiate GABA actions at the GABA(A receptor and act as central nervous system depressants that can induce effects ranging from sedation to general anesthesia. No structural information has been available about how barbiturates are recognized by their protein targets. For this reason, we tested whether these drugs were able to bind specifically to horse spleen apoferritin, a model protein that has previously been shown to bind many anesthetic agents with affinities that are closely correlated with anesthetic potency. Thiopental, pentobarbital, and phenobarbital were all found to bind to apoferritin with affinities ranging from 10-500 µM, approximately matching the concentrations required to produce anesthetic and GABAergic responses. X-ray crystal structures were determined for the complexes of apoferritin with thiopental and pentobarbital at resolutions of 1.9 and 2.0 Å, respectively. These structures reveal that the barbiturates bind to a cavity in the apoferritin shell that also binds haloalkanes, halogenated ethers, and propofol. Unlike these other general anesthetics, however, which rely entirely upon van der Waals interactions and the hydrophobic effect for recognition, the barbiturates are recognized in the apoferritin site using a mixture of both polar and nonpolar interactions. These results suggest that any protein binding site that is able to recognize and respond to the chemically and structurally diverse set of compounds used as general anesthetics is likely to include a versatile mixture of both polar and hydrophobic elements.

  12. Intraoperative awareness during general anesthesia for cesarean delivery.

    Science.gov (United States)

    Robins, Kay; Lyons, Gordon

    2009-09-01

    Intraoperative awareness is defined as the spontaneous recall of an event occurring during general anesthesia. A move away from rigid anesthetic protocols, which were designed to limit drug transmission across the placenta, has reduced the incidence of awareness during cesarean delivery to approximately 0.26%. Nevertheless, it remains an undesirable complication with potential for the development of posttraumatic stress disorder. Assessing depth of anesthesia remains a challenge for the anesthesia provider as clinical signs are unreliable and there is no sensitive and specific monitor. Bispectral Index monitoring with the goal of scores awareness. Induction drugs vary in their ability to produce amnesia and the period of hypnotic effect is affected by the rate at which they are redistributed. After initiation of anesthesia, volatile anesthetics should be administered to a target of 0.7 minimum alveolar anesthetic concentration, which has been shown to consistently achieve mean Bispectral Index scores awareness during emergency cesarean delivery. In the absence of fetal compromise, there is no rationale for an inspired oxygen concentration above 0.33. Deeper levels of anesthesia reduce the incidence of awareness; current evidence does not suggest an increased risk of tocolysis or fetal morbidity.

  13. Anesthetic management of schwannoma of the base of the tongue

    Directory of Open Access Journals (Sweden)

    Upma B Batra

    2011-01-01

    Full Text Available Schwannoma arising from the base of the tongue are very rare and only a few cases have been reported so far. Definitive diagnosis is always made after a histological examination. Apart from an anticipated difficult airway with a risk of airway obstruction upon induction of general anesthesia, anesthetic concerns also include possibility of trauma to the growth and bleeding with attendant risks. We discuss the awake fiberoptic technique used for endotracheal intubation in such a case. This case report highlights the importance of detailed history taking and clinical examination, with emphasis on airway assessment and preoperative planning.

  14. Anesthetic considerations in Leigh disease: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Abdullah Sulieman Terkawi

    2012-01-01

    Full Text Available Leigh disease is an extremely rare disorder, characterized by a progressive neurodegenerative course, with subacute necrotizing encephalomyelopathy. It usually presents in infancy with developmental delay, seizures, dysarthria, and ataxia. These patients may also develop episodes of lactic acidosis that usually lead to respiratory failure and death. Due to the rarity of the condition, the most appropriate anesthetic plan remains unclear. We present a patient with Leigh disease, who required general anesthesia. The pathogenesis of the disease is discussed and previous reports of perioperative care from the literature are reviewed.

  15. The anesthetic management in the patient with Kabuki makeup syndrome

    Directory of Open Access Journals (Sweden)

    İsmail Aydın Erden

    2013-03-01

    Full Text Available Kabuki makeup syndrome is characterized by mentalretardation, characteristic facial appearance (ektropion,skeletal abnormalities, joint laxity, short stature. The syndromeis thought to be a consequence of otosomal dominantmutation. Important factors in anesthetical managementof these patients include; difficult airway, cardiologicproblems, obstructive sleeps apne, hypotoni and malignshyperthermia risks. In this case report we aimed to discussanesthesic management of a patient with Kabukisyndrome -a rare clinical entity in our country- . J Clin ExpInvest 2013; 4 (1: 116-118Key words: kabuki makeup, tympanoplasty, general anesthesia

  16. Anesthetic management of schwannoma of the base of the tongue.

    Science.gov (United States)

    Batra, Upma B; Usha, G; Gogia, Anoop R

    2011-04-01

    Schwannoma arising from the base of the tongue are very rare and only a few cases have been reported so far. Definitive diagnosis is always made after a histological examination. Apart from an anticipated difficult airway with a risk of airway obstruction upon induction of general anesthesia, anesthetic concerns also include possibility of trauma to the growth and bleeding with attendant risks. We discuss the awake fiberoptic technique used for endotracheal intubation in such a case. This case report highlights the importance of detailed history taking and clinical examination, with emphasis on airway assessment and preoperative planning.

  17. Knowledge about local anesthetics in odontology students.

    Science.gov (United States)

    Guzmán Alvarez, Rodrigo; Campos Sepúlveda, Alfonso Efraín; Martínez González, Adrian Alejandro

    2009-01-01

    The purpose of the study was to identify the level of knowledge of local anesthetics frequently used in the surgical clinic by third and fourth year dental students in daily practice. The importance of pharmacology in dental practice in underscored by potential drug toxicity. The study was performed with 244 third and fourth grade career dental students (CDS). Eleven items regarding the knowledge over local anesthetics at the clinic; i.e., the appropriate doses, possible toxic effects and side effects were examined. The reference questionnaire which is in a validation process, is a way to evaluate student knowledge about most drugs used in odontology practice such as: NSAIDs, antibiotics and local anesthetics. The results were found to be unsatisfactory with a high percentage of students failing (less than six of eleven items correct). We conclude that determination of practice knowledge is an essential step in informing the institution about cognitive deficiencies identified in order to plan learning solutions.

  18. Anesthetic Management of a Patient With Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Ohshita, Naohiro; Oka, Saeko; Tsuji, Kaname; Yoshida, Hiroaki; Morita, Shosuke; Momota, Yoshihiro; Tsutsumi, Yasuo M

    2016-01-01

    Charcot-Marie-Tooth disease (CMTD) is a hereditary peripheral neuropathy and is characterized by progressive muscle atrophy and motor-sensory disorders in all 4 limbs. Most reports have indicated that major challenges with general anesthetic administration in CMTD patients are the appropriate use of nondepolarizing muscle relaxants and preparation for malignant hyperthermia in neuromuscular disease. Moderate sedation may be associated with the same complications as those of general anesthesia, as well as dysfunction of the autonomic nervous system, reduced perioperative respiratory function, difficulty in positioning, and sensitivity to intravenous anesthetic agents. We decided to use intravenous sedation in a CMTD patient and administered midazolam initially and propofol continuously, with total doses of 1.5 mg and 300 mg, respectively. Anesthesia was completed in 3 hours and 30 minutes without adverse events. We suggest that dental anesthetic treatment with propofol and midazolam may be effective for patients with CMTD.

  19. The modifying effect of anesthetic technique on the metabolic and endocrine responses to anesthesia and surgery

    DEFF Research Database (Denmark)

    Kehlet, H

    1988-01-01

    and the widespread use of the term "stress free anesthesia" in surgery is therefore not valid. However, continuous administration of local anesthetic agents in the epidural space is the most effective technique in so far as reduction of the stress response is concerned. The clinical implication of a variable...... reduction in the stress response to surgery by different anesthetic techniques remains largely unsettled, since only few controlled studies have been published on the clinical effects of pain relief and general anesthesia. However, a vast amount of data exist from controlled studies comparing regional...... anesthesia with local anesthetics and general anesthesia. The cumulative experience from these studies have demonstrated an advantageous effect on postoperative morbidity parameters such as blood loss, postoperative thromboembolic complications, pulmonary infective complications, gastrointestinal motility...

  20. Inhaled anesthetics have hyperalgesic effects at 0.1 minimum alveolar anesthetic concentration.

    Science.gov (United States)

    Zhang, Y; Eger, E I; Dutton, R C; Sonner, J M

    2000-08-01

    We investigated the hyperalgesic (antianalgesic) effect of the inhaled anesthetics isoflurane, halothane, nitrous oxide, and diethyl ether, or the nonimmobilizer 1, 2-dichlorohexafluorocyclobutane at subanesthetic partial pressures (or, for the nonimmobilizer, subanesthetic partial pressures predicted from lipid solubility) in rats. Hyperalgesia was assessed as a decrease in the time to withdrawal of a rat hind paw exposed to heat. All four anesthetics, including nitrous oxide and diethyl ether, produced hyperalgesia at low partial pressures, with a maximal effect at 0.1 minimum alveolar anesthetic concentration (MAC) required to prevent response to movement in 50% of animals, and analgesia (an increased time to withdrawal of the hind paw) at 0. 4 to 0.8 MAC. The nonimmobilizer had neither analgesic nor hyperalgesia effects. We propose that inhaled anesthetics with a higher MAC-Awake (the MAC-fraction that suppresses appropriate responsiveness to command), such as nitrous oxide and diethyl ether, can be used as analgesics because patients are conscious at higher anesthetic partial pressures, including those which have analgesic effects, whereas anesthetics with a lower MAC-Awake do not produce analgesic effects at concentrations that permit consciousness. The inhaled anesthetics isoflurane, halothane, nitrous oxide, and diethyl ether produce antianalgesia at subanesthetic concentrations, with a maximal effect at approximately one-tenth the concentration required for anesthesia. This effect may enhance perception of pain when such small concentrations are reached during recovery from anesthesia.

  1. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    result in an inferior model being chosen as "best" with a probability that converges to one as the sample size increases. We document the practical relevance of this problem in an empirical application and by simulation experiments. Our results provide an additional argument for using the realized...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable.......We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...

  2. STOCK MARKET VOLATILITY: DEVELOPED AND EMERGING MARKETS

    National Research Council Canada - National Science Library

    Mohammad Athar Noor; Mohd Asif Khan

    2012-01-01

      This paper examines the general patterns of recent global stock market returns and the volatility of such returns using 17 global stock indexes of countries classified into developed and emerging...

  3. Utility of Bispectral Index (BIS) monotoring during general anesthesia

    OpenAIRE

    Lindholm, Maj-Lis

    2009-01-01

    p>The possibility to objectively measure effects from anesthetics on the level of consciousness has since long been desired. General anesthetics cause changes in brain electrical activity, seen as changes in the electroencephalogram (EEG). Devices utilizing processed EEG for pseudo-quantification of anesthetic depth have been available for more than ten years. These monitors display the anesthetic, or rather, hypnotic depth as an index number. In this thesis, some aspects ...

  4. Administration and monitoring of intravenous anesthetics

    NARCIS (Netherlands)

    Sahinovic, Marko M.; Absalom, Anthony R.; Struys, Michel M. R. F.

    2010-01-01

    Purpose of review The importance of accuracy in controlling the dose-response relation for intravenous anesthetics is directly related to the importance of optimizing the efficacy and quality of anesthesia while minimizing adverse drug effects. Therefore, it is important to measure and control all

  5. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  6. Anesthetic management for cesarean delivery in a pregnant woman with polymyositis: A case report and review of literature

    OpenAIRE

    Gunusen, Ilkben; Karaman, Semra; Nemli, Seymen; FIRAT, Vicdan

    2009-01-01

    Introduction Polymyositis which is a rare disease both in general population and in pregnancy is systemic connective tissue disorder characterized by inflammation and degeneration of muscles. There is only a little information relating to the anesthetic management of a pregnant woman with polymyositis. Case presentation In this article, we present anesthetic management of urgent cesarean delivery of a 28-year-old parturient with polymyositis under epidural anesthesia who was diagnosed with po...

  7. Trigeminal nerve injury associated with injection of local anesthetics

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H.; Ersbøll, Bjarne Kjær

    2011-01-01

    anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent...

  8. Anesthetic management of a neonate with arthrogryposis multiplex congenita for emergency laparotomy

    Directory of Open Access Journals (Sweden)

    Rajat Chowdhuri

    2011-01-01

    Full Text Available Arthrogryposis multiplex congenita is a rare disease, characterized by non-progressive, multiple joint contractures since birth. Anesthetic issues include difficult intravenous access, difficult airway management and regional anesthesia. We report the anesthetic management of a six-day-old neonate presenting to the emergency with features of intestinal obstruction, who was detected for the first time to have arthrogryposis multiplex congenita. General anesthesia along with caudal analgesia for peroperative and postoperative pain relief was used. There was an episode of intraoperative hyperthermia, which was tackled successfully. The child had an uneventful post-anesthesia recovery.

  9. Child with Saethre-Chotzen syndrome: anesthetic management and literature review.

    Science.gov (United States)

    Sharma, A; Patel, N; Arora, S; Ramachandran, R

    2014-01-01

    Saethre-Chotzen syndrome (SCS) is a type of acro-cephalo-syndactyly (ACS) syndrome, characterized by premature fusion of the coronal sutures, facial dysmorphism, syndactyly, skeletal deformity, and congenital heart malformations. We here describe a child with diagnosed SCS, who underwent squint surgery under general anesthesia, and review the anesthetic concerns thereof.

  10. Combined mucopolysaccharidosis type VI and congenital adrenal hyperplasia in a child: Anesthetic considerations

    Directory of Open Access Journals (Sweden)

    Abhishek Bansal

    2012-01-01

    Full Text Available We present a child posted for magnetic resonance imaging of brain under general anesthesia with the rare combination of mucopolysachharidosis type VI and congenital adrenal hyperplasia. The presence of both these disorders has important anesthetic implications. The pathophysiology of this rare combination of disease is reviewed with emphasis on the anesthesia management.

  11. History of T-cain: a local anesthetic developed and manufactured in Japan.

    Science.gov (United States)

    Tobe, Masaru; Saito, Shigeru

    2015-10-01

    In many anesthesia textbooks written in English, lidocaine, tetracaine, bupivacaine, ropivacaine, and chloroprocaine are listed as useful local anesthetics for spinal anesthesia. In contrast, T-cain is not included in these lists, even though it has been reported to be suitable for spinal anesthesia in Japan. T-cain was developed as a local anesthetic in the early 1940s by Teikoku Kagaku Sangyo Inc. in Itami, Japan, by replacing a methyl group on tetracaine (Pantocaine(®)) with an ethyl group. T-cain was clinically approved for topical use in Japan in November 1949, and a mixture of dibucaine and T-cain (Neo-Percamin S(®)) was approved for spinal use in May 1950. Simply because of a lack of foreign marketing strategy, T-cain has never attracted global attention as a local anesthetic. However, in Japan, T-cain has been used topically or intrathecally (as Neo-Percamin S(®)) for more than 60 years. Other than the side effects generally known for all local anesthetics, serious side effects have not been reported for T-cain. In fact, several articles have reported that T-cain decreases the neurotoxicity of dibucaine. In this historical review, the characteristics of T-cain and its rise to become a major spinal anesthetic in Japan are discussed.

  12. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Science.gov (United States)

    Barodka, Viachaslau M; Acheampong, Edward; Powell, Garry; Lobach, Ludmila; Logan, David A; Parveen, Zahida; Armstead, Valerie; Mukhtar, Muhammad

    2006-01-01

    Candida albicans is a dimorphic fungus that can grow in yeast morphology or hyphal form depending on the surrounding environment. This ubiquitous fungus is present in skin and mucus membranes as a potential pathogen that under opportunistic conditions causes a series of systemic and superficial infections known as candidiasis, moniliasis or simply candidiasis. There has been a steady increase in the prevalence of candidiasis that is expressed in more virulent forms of infection. Although candidiasis is commonly manifested as mucocutaneous disease, life-threatening systemic invasion by this fungus can occur in every part of the body. The severity of candidal infections is associated with its morphological shift such that the hyphal morphology of the fungus is most invasive. Of importance, aberrant multiplication of Candida yeast is also associated with the pathogenesis of certain mucosal diseases. In this study, we assessed the anti-candidal activity of the volatile anesthetic isoflurane in liquid form in comparison with the anti-fungal agent amphotericin B in an in vitro culture system. Exposure of C. albicans to isoflurane (0.3% volume/volume and above) inhibited multiplication of yeast as well as formation of hyphae. These data suggest development of potential topical application of isoflurane for controlling a series of cutaneous and genital infections associated with this fungus. Elucidiation of the mechanism by which isoflurane effects fungal growth could offer therapeutic potential for certain systemic fungal infections. PMID:17094810

  13. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Directory of Open Access Journals (Sweden)

    Armstead Valerie

    2006-11-01

    Full Text Available Abstract Candida albicans is a dimorphic fungus that can grow in yeast morphology or hyphal form depending on the surrounding environment. This ubiquitous fungus is present in skin and mucus membranes as a potential pathogen that under opportunistic conditions causes a series of systemic and superficial infections known as candidiasis, moniliasis or simply candidiasis. There has been a steady increase in the prevalence of candidiasis that is expressed in more virulent forms of infection. Although candidiasis is commonly manifested as mucocutaneous disease, life-threatening systemic invasion by this fungus can occur in every part of the body. The severity of candidal infections is associated with its morphological shift such that the hyphal morphology of the fungus is most invasive. Of importance, aberrant multiplication of Candida yeast is also associated with the pathogenesis of certain mucosal diseases. In this study, we assessed the anti-candidal activity of the volatile anesthetic isoflurane in liquid form in comparison with the anti-fungal agent amphotericin B in an in vitro culture system. Exposure of C. albicans to isoflurane (0.3% volume/volume and above inhibited multiplication of yeast as well as formation of hyphae. These data suggest development of potential topical application of isoflurane for controlling a series of cutaneous and genital infections associated with this fungus. Elucidiation of the mechanism by which isoflurane effects fungal growth could offer therapeutic potential for certain systemic fungal infections.

  14. [Perioperative risk factors and anesthetic management of patients for carotid endarterectomy].

    Science.gov (United States)

    Niinai, H; Nakagawa, I; Shima, T; Kubota, M; Yamada, K; Kamiya, T; Yoshida, A; Yasuda, T

    1997-05-01

    Data from the records of 142 patients for carotid endarterectomy at Chugoku Rosai General Hospital between 1983 and 1995, were evaluated concerning perioperative risk factors and anesthetic management. As a preoperative anesthetic risk, the incidence of hypertension was the commonest (76%), and there was a significant incidence of ischemic heart disease (18%). Fentanyl and isoflurane have been used for anesthesia recently and the patients were closely observed and cared in the intensive care unit postoperatively. In order to prevent cerebral ischemia during the occlusion of the internal carotid artery, we measured somatosensory evoked potential as well as jugular venous oxygen saturation, and used near infrared spectophotometry. As a result, postoperative mortality and morbidity were 0% and 2%, respectively. The candidates for CEA have potentially high perioperative risks, and it is important to evaluate the coexisting diseases and to select proper anesthetic technic and monitors.

  15. Ketamine-Based Anesthetic Protocols and Evoked Potential Monitoring: A Risk/Benefit Overview

    Science.gov (United States)

    Stoicea, Nicoleta; Versteeg, Gregory; Florescu, Diana; Joseph, Nicholas; Fiorda-Diaz, Juan; Navarrete, Víctor; Bergese, Sergio D.

    2016-01-01

    Since its discovery, ketamine, a non-competitive N-methyl D-aspartate (NMDA) receptor antagonist related to phencyclidine, has been linked to multiple adverse reactions sometimes described as “out of body” and “near death experiences,” including emergence phenomena, delusions, hallucinations, delirium, and confusion. Due to these effects, ketamine has been withdrawn from mainstream anesthetic use in adult patients. Evoked potentials (EPs) are utilized to monitor neural pathways during surgery, detect intraoperative stress or damage, detect and define the level of neural lesions, and define abnormalities. Unfortunately, many of the volatile anesthetics commonly used during spinal and neurologic procedures suppress EP amplitude and monitoring. Ketamine has been found in several preclinical and clinical studies to actually increase EP amplitude and thus has been used as an analgesic adjunct in procedures where EP monitoring is critical. Once the gap in our knowledge of ketamine's risks has been sufficiently addressed in animal models, informed clinical trials should be conducted in order to properly incorporate ketamine-based anesthetic regimens during EP-monitored neurosurgeries. PMID:26909017

  16. Pacemakers and implantable cardioverter defibrillators - general and anesthetic considerations

    Directory of Open Access Journals (Sweden)

    Amy G. Rapsang

    2014-06-01

    Full Text Available A pacemaking system consists of an impulse generator and lead or leads to carry the electrical impulse to the patient's heart. Pacemaker and implantable cardioverter defibrillator codes were made to describe the type of pacemaker or implantable cardioverter defibrillator implanted. Indications for pacing and implantable cardioverter defibrillator implantation were given by the American College of Cardiologists. Certain pacemakers have magnet-operated reed switches incorporated; however, magnet application can have serious adverse effects; hence, devices should be considered programmable unless known otherwise. When a device patient undergoes any procedure (with or without anesthesia, special precautions have to be observed including a focused history/physical examination, interrogation of pacemaker before and after the procedure, emergency drugs/temporary pacing and defibrillation, reprogramming of pacemaker and disabling certain pacemaker functions if required, monitoring of electrolyte and metabolic disturbance and avoiding certain drugs and equipments that can interfere with pacemaker function. If unanticipated device interactions are found, consider discontinuation of the procedure until the source of interference can be eliminated or managed and all corrective measures should be taken to ensure proper pacemaker function should be done. Post procedure, the cardiac rate and rhythm should be monitored continuously and emergency drugs and equipments should be kept ready and consultation with a cardiologist or a pacemaker-implantable cardioverter defibrillator service may be necessary.

  17. Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status.

    Science.gov (United States)

    Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

    2014-01-01

    It is controversial that whether the GABA receptors contribute to the hypnotic action of volatile anesthetics. This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration-awake (MAC-Awake) and emergence mental status. This study included two steps. Firstly, 49 healthy patients, aged 20-40 years scheduled for elective surgeries, were randomly assigned to two groups, a flumazenil group (n=24) and a saline group (n=25). The flumazenil group received 0.006 mg/Kg IV, and the control group received the same volume of saline 20 min before induction. The flumazenil group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command). We used the mask inhalation to measure the MAC-Awake by up-and-down method. The second steps, 60 patients undergoing lower abdomen surgeries were randomly divided into two groups, a experimental group (n=30) and a saline group (n=30). All patients were anesthetized with sevoflurane/sulfentanil. The experimental group received flumazenil at 0.006 mg/Kg IV, and the control group received the same volume of saline at the end of surgery. We recorded the time to awake and extubation. After extubation, the patients' recovery status was scored with the Mini-Mental state examination (MMSE) system in post anesthesia care unit (PACU). The MAC-Awake was 0.65% in the control group and 0.82% in the flumazenil group (p=0.34). After extubation, the recovery time and time to extubation showed no difference between the flumazenil group and the saline group (p>0.05). But the 10 min and 15 min MMSE scores after extubation were better in the flumazenil group than those in the saline group (pMAC-Awake in humans. A single intravenous injection of flumazenil (0.006 mg/Kg) can partially reverse the hypnotic effect of

  18. Clinical application of thoracic paravertebral anesthetic block in breast surgeries

    Directory of Open Access Journals (Sweden)

    Sara Socorro Faria

    2015-04-01

    Full Text Available INTRODUCTION: Optimum treatment for postoperative pain has been of fundamental importance in surgical patient care. Among the analgesic techniques aimed at this group of patients, thoracic paravertebral block combined with general anesthesia stands out for the good results and favorable risk-benefit ratio. Many local anesthetics and other adjuvant drugs are being investigated for use in this technique, in order to improve the quality of analgesia and reduce adverse effects. OBJECTIVE: Evaluate the effectiveness and safety of paravertebral block compared to other analgesic and anesthetic regimens in women undergoing breast cancer surgeries. METHODS: Integrative literature review from 1966 to 2012, using specific terms in computerized databases of articles investigating the clinical characteristics, adverse effects, and beneficial effects of thoracic paravertebral block. RESULTS: On the selected date, 16 randomized studies that met the selection criteria established for this literature review were identified. Thoracic paravertebral block showed a significant reduction of postoperative pain, as well as decreased pain during arm movement after surgery. CONCLUSION: Thoracic paravertebral block reduced postoperative analgesic requirement compared to placebo group, markedly within the first 24 h. The use of this technique could ensure postoperative analgesia of clinical relevance. Further studies with larger populations are necessary, as paravertebral block seems to be promising for preemptive analgesia in breast cancer surgery.

  19. Opioid induced hyperalgesia in anesthetic settings.

    Science.gov (United States)

    Lee, Hyeon Jeong; Yeomans, David C

    2014-11-01

    Pain is difficult to investigate and difficult to treat, in part, because of problems in quantification and assessment. The use of opioids, combined with classic anesthetics to maintain hemodynamic stability by controlling responses to intraoperative painful events has gained significant popularity in the anesthetic field. However, several side effects profiles concerning perioperative use of opioid have been published. Over the past two decades, many concerns have arisen with respect to opioid-induced hyperalgesia (OIH), which is the paradoxical effect wherein opioid usage may decrease pain thresholds and increase atypical pain unrelated to the original, preexisting pain. This brief review focuses on the evidence, mechanisms, and modulatory and pharmacologic management of OIH in order to elaborate on the clinical implication of OIH.

  20. Hypoxic pulmonary vasoconstriction: physiology and anesthetic implications.

    Science.gov (United States)

    Lumb, Andrew B; Slinger, Peter

    2015-04-01

    Hypoxic pulmonary vasoconstriction (HPV) represents a fundamental difference between the pulmonary and systemic circulations. HPV is active in utero, reducing pulmonary blood flow, and in adults helps to match regional ventilation and perfusion although it has little effect in healthy lungs. Many factors affect HPV including pH or PCO2, cardiac output, and several drugs, including antihypertensives. In patients with lung pathology and any patient having one-lung ventilation, HPV contributes to maintaining oxygenation, so anesthesiologists should be aware of the effects of anesthesia on this protective reflex. Intravenous anesthetic drugs have little effect on HPV, but it is attenuated by inhaled anesthetics, although less so with newer agents. The reflex is biphasic, and once the second phase becomes active after about an hour of hypoxia, this pulmonary vasoconstriction takes hours to reverse when normoxia returns. This has significant clinical implications for repeated periods of one-lung ventilation.

  1. [Rectal administration of anesthetic agents].

    Science.gov (United States)

    Ceriana, P; Maurelli, M

    1995-05-01

    To collect data in the current literature dealing with the diffusion, the reliability and the effectiveness of the rectal administration of anaesthetic drugs. To evaluate differences with parenteral administration. Pharmacokinetics and clinical studies published in recent years in indexed journals. Based on the study methodology, drugs employed and pharmacokinetic parameters evaluated. Factors involved in absorption of drugs from the rectal mucosa, clinical effect and pharmacokinetic data of the following drugs: diazepam, flunitrazepam, midazolam, ketamin and methohexital, then a brief evaluation of other drugs: thiopental, etomidate, morphine and chloral hydrate. The most widely used drugs are benzodiazepines: they are safe, easy to manage and highly effective; among them midazolam has the best kinetic and dynamic pattern. Ketamin is useful during painful diagnostic procedures; with the use of barbiturates there is a greater risk of respiratory depression and more caution must be employed. Wide intervariability of rate of absorption, achievement of plasma levels and clinical effect is a relevant drawback of this technique, such to make it not preferable to the parenteral route, when both are feasible. It deserves, anyway, more consideration, and maintains its validity for the preparation of the paediatric patient to general anaesthesia.

  2. [Tropical Spastic paraparesis - anesthetic approach].

    Science.gov (United States)

    Rodrigues, Margarida; Cabral, Francisco; Pina, Fátima

    2015-11-25

    HTLV-1 infection is endemic in Japan, Caribbean, Africa, and South America. It is transmitted from mother to child, sexual contact, blood transfusions, or sharing needles. Tropical Spastic paraparesis (TSP) is a chronic degenerative neurological disease associated with this infection. It results from a spinal cord symmetrical degeneration at the thoracic level and is characterized by progressive motor weakness in the lower limbs, hyperreflexia, sensitivity changes, urinary incontinence, and bladder dysfunction. Female, 53 years old, HTLV-1 infection and TSP. She had decreased strength in the lower limbs and hyperreflexia, paretic gait, spasticity, and neurogenic bladder symptoms, with recurrent urinary infections. She was scheduled for cystectomy. The patient was monitored according to standard ASA. Due to severe coagulopathy and the possibility of neurological worsening, epidural catheter was not placed. The induction of general anesthesia was performed with midazolam and fentanyl, followed by etomidate and cisatracurium. She was intubated with a tube size seven and maintained with desflurane and oxygen. Anesthesia was uneventful; the surgery lasted 1 hour and 50minutes. There were no complications in the immediate postoperative period, during hospitalization, nor deterioration of the neurological examination. The patient was discharged 20 days later. There are reports of decreased electromyographic response and neurological deterioration associated with propofol in these patients, etomidate was used. The hepatic metabolism of rocuronium posed a risk, we chose to use cistracurium. It was concluded that the anesthesia chosen did not affect the course of the disease. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  3. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  4. Asymmetry Effects of shocks in Chinese Stock Markets Volatility

    DEFF Research Database (Denmark)

    Hou, Ai Jun

    2013-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies...... a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chinese stock markets. Furthermore, compared with other parametric models, the generalized additive...

  5. Emerging Equity Market Volatility

    OpenAIRE

    Geert Bekaert; Harvey, Campbell R.

    1995-01-01

    Returns in emerging capital markets are very different from returns in developed markets. While most previous research has focused on average returns, we analyze the volatility of the returns in emerging equity markets. We characterize the time-series of volatility in emerging markets and explore the distributional foundations of the variance process. Of particular interest is evidence of asymmetries in volatility and the evolution of the variance process after periods of capital market refor...

  6. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  7. Epidermolysis Bullosa, Dental and Anesthetic Management: A Case Report

    Directory of Open Access Journals (Sweden)

    Katayoun Esfahanizadeh

    2014-09-01

    Full Text Available Epidermolysis bullosa (EB is a group of rare inherited skin and mucous membrane disorders in which blister formation may arise spontaneously or following a minor friction. Various patterns of inheritance are explicated for the disease. The disease has a profound effect on oral mucosa and may result in high prevalence of dental caries. General anesthesia is sometimes the only choice for dental treatments in patients with EB. The following case report describes the dental and anesthetic management of an 12.5 -year-old girl with dystrophic type of EB. The patient was followed up every 6 months. New carious lesions were detected one year after the treatment, on the last visit. Presenting a perfect dental care to children with this disorder can be challenging for the in charge specialist, both pediatric dentist and anesthesiologist.

  8. Epidermolysis bullosa, dental and anesthetic management: a case report.

    Science.gov (United States)

    Esfahanizade, Katayoun; Mahdavi, Ali Reza; Ansari, Ghassem; Fallahinejad Ghajari, Masoud; Esfahanizadeh, Abdolreza

    2014-09-01

    Epidermolysis bullosa (EB) is a group of rare inherited skin and mucous membrane disorders in which blister formation may arise spontaneously or following a minor friction. Various patterns of inheritance are explicated for the disease. The disease has a profound effect on oral mucosa and may result in high prevalence of dental caries. General anesthesia is sometimes the only choice for dental treatments in patients with EB. The following case report describes the dental and anesthetic management of an 12.5 -year-old girl with dystrophic type of EB. The patient was followed up every 6 months. New carious lesions were detected one year after the treatment, on the last visit. Presenting a perfect dental care to children with this disorder can be challenging for the in charge specialist, both pediatric dentist and anesthesiologist.

  9. Use of pethidine as an intravenous regional anesthetic.

    Science.gov (United States)

    el-Bakry, M S; el-Shafei, S B; Seyam, E M; el-Kobbia, N M; Ebrahim, U H

    1989-06-01

    Pethidine 100 mg in 30-40 ml saline was given in a group of patients by the conventional technique of intravenous regional anesthesia. Fourty percent of the patients did not feel any form of pain or discomfort, 26.7% experienced only vague sensations which did not call for additional drugs but 13.3% felt some form of pain or discomfort for which diazepam was given and was enough for surgery to be completed. In the rest of the patients (20%) there was intolerable pain for which patients were given general anesthesia. This last category was operated upon for recent fractures or digital conditions and it is known that intravenous regional anesthesia using conventional local anesthetics for such patients usually fails. In a control group in which 30-40 ml saline without pethidine were injected, there was complete failure of the technique.

  10. Upper airway collapsibility in anesthetized children.

    Science.gov (United States)

    Litman, Ronald S; McDonough, Joseph M; Marcus, Carole L; Schwartz, Alan R; Ward, Denham S

    2006-03-01

    We sought to establish the feasibility of measuring upper airway narrowing in spontaneously breathing, anesthetized children using dynamic application of negative airway pressure. A secondary aim was to compare differences in upper airway collapsibility after the administration of sevoflurane or halothane. Subjects were randomized to either drug for inhaled anesthetic induction. Each was adjusted to their 1 MAC value (0.9% for halothane and 2.5% for sevoflurane) and a blinded anesthesia provider held the facemask without performing manual airway opening maneuvers but with inclusion of an oral airway device. Inspiratory flows were measured during partial upper airway obstruction created by an adjustable negative pressure-generating vacuum motor inserted into the anesthesia circuit. Critical closing pressure of the pharynx (Pcrit) was obtained by plotting the peak inspiratory flow of the obstructed breaths against the corresponding negative pressure in the facemask and extrapolating to zero airflow using linear correlation. Fourteen children were enrolled, seven in each anesthetic group. Two children in the halothane group did not develop flow-limited airway obstruction despite negative pressures as low as -9 cm H2O. Pcrit for sevoflurane ranged from -6.7 to -11.6 (mean +/- sd, -9.8 +/- 1.9) cm H2O. Pcrit for halothane ranged from -8.1 to -33 (mean +/- sd, -19.4 +/- 9.3) cm H2O (sevoflurane versus halothane, P = 0.048). We conclude that when using dynamic application of negative airway pressure, halothane appears to cause less upper airway obstruction than sevoflurane at equipotent concentrations.

  11. Differential Postoperative Effects of Volatile Anesthesia and Intraoperative Remifentanil Infusion in 7511 Thyroidectomy Patients

    Science.gov (United States)

    Jo, Jun-Young; Choi, Seong-Soo; Yi, Jung Min; Joo, Eun Young; Kim, Ji Hyun; Park, Se Ung; Sim, Ji-Hoon; Karm, Myong-Hwan; Ku, Seungwoo

    2016-01-01

    Abstract Although remifentanil is used widely by many clinicians during general anesthesia, there are recent evidences of opioid-induced hyperalgesia as an adverse effect. This study aimed to determine if intraoperative remifentanil infusion caused increased pain during the postoperative period in patients who underwent a thyroidectomy. A total of 7511 patients aged ≥ 20 years, who underwent thyroidectomy between January 2009 and December 2013 at the Asan Medical Center were retrospectively analyzed. Enrolled patients were divided into 2 groups: group N (no intraoperative remifentanil and only volatile maintenance anesthesia) and group R (intraoperative remifentanil infusion including total intravenous anesthesia and balanced anesthesia). Following propensity score matching analysis, 2582 patients were included in each group. Pain scores based on numeric rating scales (NRS) were compared between the 2 groups at the postoperative anesthetic care unit and at the ward until 3 days postoperation. Incidences of postoperative complications, such as nausea, itching, and shivering were also compared. The estimated NRS pain score on the day of surgery was 5.08 (95% confidence interval [CI] 4.97–5.19) in group N patients and 6.73 (95% CI 6.65–6.80) in group R patients (P < 0.001). There were no statistically significant differences in NRS scores on postoperative days 1, 2, and 3 between the 2 groups. Postoperative nausea was less frequent in group R (31.4%) than in group N (53.5%) (P < 0.001). However, the incidence of itching was higher in group R (4.3%) than in group N (0.7%) (P < 0.001). Continuous infusion of remifentanil during general anesthesia can cause higher intensity of postoperative pain and more frequent itching than general anesthesia without remifentanil infusion immediately after thyroidectomy. Considering the advantages and disadvantages of continuous remifentanil infusion, volatile anesthesia without opioid may be a good choice for minor

  12. Local anesthetics as pain therapy in horses.

    Science.gov (United States)

    Doherty, Thomas J; Seddighi, M Reza

    2010-12-01

    This article describes the rationale behind the use of systemically administered lidocaine as an analgesic. The analgesic efficacy of intravenously administered lidocaine is well documented by studies in human patients and laboratory animals. The mechanism by which systemically administered lidocaine produces analgesia is uncertain but is thought to include action at sodium, calcium, and potassium channels and the N-methyl-D-aspartate acid receptor. In addition, the anti-inflammatory actions of lidocaine are important in producing analgesia because inflammatory mediators augment neuronal excitability. The available studies of systemically administered lidocaine in horses provide evidence for the analgesic and anesthetic effects of intravenous lidocaine in this species.

  13. Gestational trophoblastic disease with hyperthyroidism: Anesthetic management

    Directory of Open Access Journals (Sweden)

    Puneet Khanna

    2012-01-01

    Full Text Available The coexistence of hyperthyroidism with gestational trophoblastic disease is a known albeit rare clinical condition. We herein report the successful anesthetic management of such a case in our institute. There are only few case reports in literature of this association. Often, the diagnosis of hyperthyroid state is retrospective one, as it can be missed in the emergency scenario of patient requiring molar evacuation. This case report highlights the perioperative management and optimization of hyperthyroid state prior to surgical evacuation of the invasive hydatidiform mole.

  14. Anesthetic considerations in Sheldon-Hall syndrome.

    Science.gov (United States)

    Anderson, Thomas Anthony; Kasser, James R; Holzman, Robert S

    2014-05-01

    Arthrogryposis is characterized by multiple, nonprogressive joint contractures which may be caused by maternal disorders such as oligohydramnios as well as fetal akinesia resulting from primary disorders of muscle, connective tissue, or neurologic tissue. Its prevalence is about 1 : 3000. Distal arthrogryposis (DA) is a heterogenous group of genetic disorders with a characteristic flexion of the joints of the hands and feet divided into different types with additional features. Sheldon-Hall Syndrome (SHS), also known as distal arthrogryposis type 2A (DA2A), has some nonorthopedic features of specific importance to anesthetic care.

  15. Mimosa pudica, Dionaea muscipula and anesthetics.

    Science.gov (United States)

    De Luccia, Thiago Paes de Barros

    2012-09-01

    Some studies showed that anesthetics reduce the response of physical stimuli in Mimosa pudica and in Venus Flytrap (Dionaea muscipula), peculiar plants that have the ability to respond to touch stimuli. In this research we tested the effects of ketamine, lidocaine, diethyl ether, and amlodipine on the movements of Mimosa pudica and Venus Flytrap. With a literature review, we tried to bring elements to theorize about the interaction of these substances with these plants. The angular displacement in Mimosa´s petiole and in Dionaea leaves is what was measured to compare the drugs group with control groups.

  16. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over time. Wi

  17. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  18. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  19. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and ident...

  20. Age, minimum alveolar anesthetic concentration, and minimum alveolar anesthetic concentration-awake.

    Science.gov (United States)

    Eger, E I

    2001-10-01

    Two defining effects of inhaled anesthetics (immobility in the face of noxious stimulation, and absence of memory) correlate with the end-tidal concentrations of the anesthetics. Such defining effects are characterized as MAC (the concentration producing immobility in 50% of patients subjected to a noxious stimulus) and MAC-Awake (the concentration suppressing appropriate response to command in 50% of patients; memory is usually lost at MAC-Awake). If the concentrations are monitored and corrected for the effects of age and temperature, the concentrations may be displayed as multiples of MAC for a standard age, usually 40 yr. This article provides an algorithm that might be used to produce such a display, including provision of an estimate of the effect of nitrous oxide. Two defining effects of inhaled anesthetics (immobility in the face of noxious stimulation, and absence of memory) correlate with the end-tidal concentrations of the anesthetics. Thus, these defining effects may be monitored and the results displayed if the concentrations are known and corrected for the effects of age and temperature.

  1. Anesthetic management of dental procedures in patients with special needs: A retrospective analysis of 519 patients in North of Turkey

    OpenAIRE

    YILMAZ, Mehmet; ÇAĞLAR TORUN, Aysun; Baş, Burcu; DURAN, Hatice; KÖSE, İlyas; FURUNCUOĞLU, Halit

    2015-01-01

    Special need patients have increased risk for oral diseases throughout their life. Sedation and general anesthesia is generally the preferred treatment for special needs patients though it provides optimal conditions for dental treatment. This study was aimed to describe our anesthetic experience in dental treatments of 519 special needs patients at a dental faculty in the north side of Turkey during a three-year period. The data referring to patient’s demographic information, anesthetic tech...

  2. The effects of anesthetic technique and ambient temperature on thermoregulation in lower extremity surgery.

    Science.gov (United States)

    Ozer, Ayse B; Tosun, Fadime; Demirel, Ismail; Unlu, Serap; Bayar, Mustafa K; Erhan, Omer L

    2013-08-01

    The purpose of our study was to determine the effects of anesthetic technique and ambient temperature on thermoregulation for patients undergoing lower extremity surgery. Our study included 90 male patients aged 18-60 years in American Society of Anesthesiologists Physical Status groups I or II who were scheduled for lower extremity surgery. Patients were randomly divided into three groups according to anesthetic technique: general anesthesia (GA), epidural anesthesia (EA), and femoral-sciatic block (FS). These groups were divided into subgroups according to room temperature: the temperature for group I was 20-22 °C and that for group II was 23-25 °C. Therefore, we labeled the groups as follows: GA I, GA II, EA I, EA II, FS I, and FS II. Probes for measuring tympanic membrane and peripheral temperature were placed in and on the patients, and mean skin temperature (MST) and mean body temperature (MBT) were assessed. Postoperative shivering scores were recorded. During anesthesia, tympanic temperature and MBT decreased whereas MST increased for all patients. There was no significant difference between tympanic temperatures in either the room temperature or anesthetic method groups. MST was lower in group GA I than in group GA II after 5, 10, 15, 20, 60 and 90 min whereas MBT was significantly lower at the basal level (p thermoregulation among anesthetic techniques. Room temperature affected thermoregulation in Group GA.

  3. Risk of acquired methemoglobinemia with different topical anesthetics during endoscopic procedures

    Directory of Open Access Journals (Sweden)

    Vallurupalli S

    2011-07-01

    Full Text Available Srikanth Vallurupalli1, Shalini Manchanda21Division of General Internal Medicine, Department of Medicine, Southern Illinois University School of Medicine, Springfield, IL, USA; 2Division of Pulmonary, Allergy, Critical Care, and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USAIntroduction: Methemoglobinemia is a recognized complication of the use of topical anesthetic sprays. The true scope of the problem or the risk with different topical anesthetic sprays and endoscopic procedures is unknown.Methods: We retrospectively identified all cases of methemoglobinemia that occurred in a university affiliated community hospital from 2001 to 2007.Results: Eleven cases of methemoglobinemia were identified over the 6-year period. Nine (82% occurred with use of benzocaine spray during transesophageal echocardiography (TEE. Patients who developed methemoglobinemia secondary to the topical anesthetic spray compared to other causes were more likely to be older, have lower mean hemoglobin levels (10.5 ± 0.5 g/dL vs 11.3 ± 0.0 g/dL, and a higher mean methemoglobin concentration at diagnosis (40.8% ± 5.2% vs 24% ± 10%. However, only age reached statistical significance (P = 0.004.Conclusion: In a university-affiliated community hospital, topical anesthetic sprays account for most of the burden of methemoglobinemia. Benzocaine use in the context of TEE caused more methemoglobinemia compared to lidocaine and other endoscopic procedures. This observation supports previous data and findings deserve further study.Keywords: methemoglobinemia, benzocaine, lidocaine, transesophageal echocardiography, endoscopy

  4. Asymmetry Effects of shocks in Chinese Stock Markets Volatility

    DEFF Research Database (Denmark)

    Hou, Ai Jun

    2013-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies a ge...... nonparametric model demonstrates a better performance for return volatility forecasts, particularly for the out-of-sample forecast. The results from this paper have important implications in risk management, portfolio selection, and hedging strategy.......The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies...... a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chinese stock markets. Furthermore, compared with other parametric models, the generalized additive...

  5. 复方利多卡因乳膏对喉罩插入不良反应的抑制作用%Surface anesthetic effect of compound lidocaine cream-coated laryngeal mask airway in patients undergoing modified radical mastectomy under general anesthesia

    Institute of Scientific and Technical Information of China (English)

    张锦英; 沈途

    2011-01-01

    目的 观察复方利多卡因乳膏乳癌改良根治术中喉罩插入时不良反应的抑制作用.方法 择期行全麻乳癌改良根治术的患者80例,ASA Ⅰ~Ⅲ级,随机均分为复方利多卡因乳膏喉罩组(A组)和石蜡油喉罩组(B组),将复方利多卡因乳膏和石蜡油涂抹于喉罩表面.麻醉诱导后插入喉罩,记录麻醉诱导前、喉罩插入前、喉罩插入即刻及喉罩插人后3 min患者SBP、DBP、HR,以及术后咽痛或咽部不适的发生率.结果 与喉罩插入前和A组比较,B组喉罩插入即刻和喉罩插入后3min时SBP、DBP明显升高,HR明显增快(P<0.01).A组患者术中呛咳和术后咽痛、咽部不适感发生率明显低于B组(P<0.05).结论 复方利多卡因乳膏能有效抑制全麻乳癌改良根治术中喉罩插人所引起的咽反射和术后咽痛.%Objective To evaluate the surface anesthetic effect of compound lidocaine crearcoated laryngeal mask airway (LMA) in patients undergoing modified radical mastectomy under general anesthesia. Methods Eighty ASA Ⅰ-Ⅲ patients undergoing modified radical mastectomy under general anesthesia received insertion of LMA coated with either compound lidocaine cream (group A, n = 40) or paraffin oil (group B, n = 40). Systolic blood pressure(SBP), diastolic blood pressure(DBP) and heart rate(HR)were measured during LMA insertion. Incidence of irritating cough and sore throat was recorded after operation. Results Compared with group B, not only SBP, DBP or HR at 0 min, 3 min after LMA insertion were lower, but the incidence of irritating cough and sore throat was significantly also lower in group A (P<0. 01). SBP, DBP and HR at 0 min, 3 min after LMA insertion was higher than that before LMA insertion in B group ( P< 0. 01 ). Conclusion Compound lidocaine cream-coated LMA can inhibit the pharyngeal reaction and reduce the incidence of sore throat in patients undergoing modified radical mastectomy under general anesthesia.

  6. 复方利多卡因乳膏在喉罩全麻腹腔镜胆囊切除术中的应用%Surface anesthetic effect of compound lidocaine cream-coated laryngeal mask airway in patients undergoing laparoscopic cholecystectomy and general anesthesia

    Institute of Scientific and Technical Information of China (English)

    卢静; 兰志勋

    2009-01-01

    目的 观察复方利多卡因在喉罩全麻腹腔镜胆囊切除术中抑制咽反射和术后咽喉痛的效果.方法 将120例ASA Ⅰ~Ⅲ级择期行全麻腹腔镜胆囊切除术的患者随机分为试验组(A组,n=60)和对照组(B组,n=60),分别将复方利多卡因乳膏和石蜡油涂抹于喉罩表面,在麻醉诱导后王入喉罩,记录麻醉诱导前、喉罩置入前、喉罩置入即刻及喉罩置入后3min患者收缩压(SBP)、舒张压(DBP)、心率(HR)以及术后咽痛或咽部不适的发生率.结果 与置入喉罩前相比,A组患者置入喉罩后即刻和置入喉罩后3min时SBP、DBP、HR差异无统计学意义(P>0.05);B组患者上述指标则明显升高,差异有统计学意义(P<0.01).组间比较,A组置入喉罩后的SBP、DBP、HR均低于B组,差异有统计学意义(P<0.01).A组患者术中呛咳和术后咽痛、咽部不适感发生率明显低于B组(P<0.05).结论 复方利多卡因乳膏能有效抑制喉罩全麻胆囊切除术所引起的咽反射和术后咽痛.%Objective To evaluate the surface anesthetic effect of compound lidocaine cream-coated laryngeal mask air-way (LMA) in patients undergoing laparoscopic cholecystectomy (LC) and general anesthesia. Methods 120 ASA Ⅰ~Ⅲ pa-tients undergoing LC and general anesthesia received insertion of LMA coated with either compound lidocaine cream ( A group, n=60) or paraffin oil (B group, n=60). Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured during LMA insertion. Irritating cough, sore throat were recorded after operation. Results Compared with B group, not only SBP, DBP and HR at 0min,3min after LMA insertion but also the incidence of irritating cough and sore throat was significantly lower in A group (P<0.01). No difference was observed in SBP, DBP and HR before LMA insertion, at 0min, 3min after LMA insertion in A group but SBP, DBP and HR at Omin,3min after LMA insertion was higher than that before LMA insertion

  7. [Seishu Hanaoka Did Not Describe His Anesthetic as Tsusensan--A Misunderstanding of the Terms Mafutsusan and Tsusensan].

    Science.gov (United States)

    Matsuki, Akitomo

    2015-10-01

    It is widespread even among medical professionals as well as medical historians that the formal term of the general anesthetic that Hanaoka developed is Tsusensan and its alias name is Mafutsusan. Hanaoka himself, however, described it as Mafutsusan in his Nyugan Chikenroku, the case report of the first breast cancer excision under general anesthesia with the anesthetic, and a large number of his disciples all used the term Mafutsusan to denote the anesthetic in their manuscripts. The description of Tsusensan has not been found in the documents written in the Edo period, and this name is detected only in the epitaph of Hanaoka. Consequently, we should refer to Hanaoka's anesththetic as "Mafutsusan, another name Tsusensan" instead of "Tsusensan, another name Mafutsusan."

  8. [A regular internal auditing and registration of critical incidents regarded as safety maintenance elements within the anesthetic management of patients].

    Science.gov (United States)

    Vinogradov, V L; Likhvantsev, V V; Alekseev, A A

    2004-01-01

    The paper summarizes a 5-year experience of evaluating the safety of anesthetic management of patients with thermal lesions treated at the department of thermal lesions of Vishnevsky's Institute of Surgery, Russia's Academy of Medical Sciences. Regular internal auditings, based on the principles of registering the critical incidents, the course of 1473 general anesthesia managements was analyzed in 168 patients. The conclusion is that the introduction of protocols of anesthetic management as well as a regular monitoring over meeting the fixed targets cut the total frequency of critical incidents from 2.85 to 1.19 as estimated per one general anesthesia. Finally the authors suggest a concept whose essence in that the operation of the modern anesthesiology department must be based on a scientifically substantiated technology of anesthetic management.

  9. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos;

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong......In this paper, we scrutinize the cross-sectional relation between idiosyncratic volatility and stock returns. As a novelty, the idiosyncratic volatility is obtained by conditioning upon macro-Önance factors as well as upon traditional asset pricing factors. The macro-Önance factors are constructed...

  10. A survey to access knowledge and practice among dentists regarding local anesthetic dosage in three cities of Uttarakhand

    Directory of Open Access Journals (Sweden)

    Laxman Singh Kaira

    2014-01-01

    Full Text Available Objective: Local anesthetics are the most commonly used drugs in routine dentistry. Although they are considered effective and safe in controlling pain during dental procedures, complications related to their use appear inevitable. Many dentists use these drugs routinely but are unaware of the dose calculations required and the maximum safe and effective dose of the drug. Materials and Methods: This study was aimed to determine the knowledge that general dental practitioners and dental specialists, in three different cities in India, have regarding dose calculations and the maximum-dose required of the most commonly used local anesthetics. A one page survey questionnaire was used in this study and data were analyzed using standard SPSS statistical program version 11, software (SPSS Inc. Chicago, Illinois, USA. Results: The respondents comprised 71.4% general dental practitioners and 28.5% dental specialists, with ages ranging from 26 to 50 years; Nearly 75% of the total respondent was males and 25% females. Nearly 69% of the respondents were unaware of the maximum recommended dose for use on adult, healthy patients and 81% were still confused about the maximum numbers of syringes containing 2% lignocaine with adrenaline that can be given to a patient. A total of 49% of general dental practitioners and specialists do not perform aspiration when injecting local anesthetics, whereas only 38% performed the aspiration in inferior nerve block technique, while only 12% performed aspiration in all types of injection techniques. A high percentage of the dentists (84% who responded are unaware of how to calculate the local anesthetic dose and 31% of them encountered complications during, or after, local anesthetic administration. Conclusion: General practitioners and dental specialists appear to have an inadequate knowledge about local anesthetics maximum-dose and dose calculations; further educational courses are recommended to update them regarding such

  11. Stochastic Volatility and Option Pricing in Heath-Jarrow-Morton Term Structure Analysis

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Konaris, George; Nicolato, Elisa

    We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented.......We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented....

  12. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic cabinet, table, or tray. 868.6100 Section 868.6100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  13. Anesthetic Management of a Pediatric Patient With Wilsons Disease

    Science.gov (United States)

    Baykal, Mehmet; Karapolat, Sami

    2010-01-01

    Wilsons disease, characterized by cirrhosis, extrapyramidal symptoms and Kayser-Fleischer corneal rings, is a rare hereditary disease of human copper metabolism. Clinical findings in Wilsons disease are complex and neurological symptoms such as tremor, dysarthria, rigid dystonia, seizures, psychiatric disorders, acute liver failure, chronic hepatitis or cirrhosis may develop. A 4-year-old male patient was operated for traumatic depressed skull fracture and intracerebral hematoma. He was diagnosed with Wilsons disease at the age of 2.5 years and treated with zinc sulphate and D-penicillamine. General anesthesia was induced with propofol, fentanyl, atracurium, and maintained with isoflurane, and oxygen. No complications were encountered during the operation or in the postoperative period. We concluded that general anesthesia can successfully be given to Wilsons disease patients using an anesthetic agent, the metabolism of which is least affected by the liver disease, one that induces least hepatic toxicity. By close follow-up of patients clinically and biochemically, it is possible to reduce the complication rates to a minimum. Keywords Wilson's Disease; Craniocerebral trauma; Thoracic injuries; General anesthesia; Surgery PMID:21811529

  14. Mantle Volatiles - Distribution and Consequences

    Science.gov (United States)

    Luth, R. W.

    2003-12-01

    Volatiles in the mantle have, for many years, been the subject of intensive study from a number of perspectives. They are of interest because of their potential effects on melting relationships, on transport of major and trace elements, and on the rheological and other physical properties of the mantle. By convention, "volatiles" in this context are constituents that are liquid or gaseous at normal Earth surface conditions. This review will look at the behavior of C-O-H-S-halogen volatiles, beginning with H2O and C-O volatiles.There have been tremendous strides made recently towards understanding how volatiles in general and water in particular is transported and stored in the mantle. This progress is based on research on a number of fronts: studies of mantle-derived samples have provided insight into the nature and occurrence of hydrous phases such as amphibole, mica, and chlorite, and have provided constraints on the capacity of nominally anhydrous minerals (NAMs) such as olivine, pyroxenes, and garnet to contain "water" by a variety of substitution mechanisms. Experimental studies on mantle-derived magmas have provided constraints on volatile contents in their source regions. Other studies have constrained the pressure, temperature, and composition conditions over which hydrous phases are stable in the mantle.Fundamental questions remain about the geochemical cycling of volatiles in the mantle, and between the mantle and the surface. Much attention has focused on the capability of hydrous phases such as amphibole, mica, serpentine, chlorite, and a family of "dense hydrous magnesian silicates" (DHMSs) to act as carriers of water in subducting slabs back into the mantle. It has been clear since the work of Ito et al. (1983) that there is a discrepancy between the amount of volatiles subducted into the mantle and those returned to the surface by arc magmatism. A recent overview of volatile cycling in subduction systems by Bebout (1996) suggests that 5-15% of the H2

  15. Identifying and Managing Local Anesthetic Allergy in Dermatologic Surgery.

    Science.gov (United States)

    Fathi, Ramin; Serota, Marc; Brown, Mariah

    2016-02-01

    Local anesthetic (LA) allergy is a concern for dermatologic surgeons given the large number of procedures performed yearly with LAs. Many patients also have anxiety about past or potential anesthesia allergy. This article will review the symptoms of IgE-mediated allergic reactions, the prevalence of IgE-mediated LA allergy, discuss common mimics of LA, and propose a practical approach for diagnostic and therapeutic options for LA allergy for the dermatologic surgeon in practice. A literature search of Pubmed using keywords "lidocaine," "local anesthetic," "hypersensitivity," and "allergy" was performed. Amide anesthetics result in the most reports of true local anesthetic immediate hypersensitivity. True IgE-mediated anaphylaxis to local anesthesia is very rare. Dermatologic surgeons should be aware of the symptoms of anesthetic allergy and its mimickers, as well as how to manage allergic reactions in their clinical practice.

  16. On guidance and volatility

    NARCIS (Netherlands)

    Billings, M.B.; Jennings, R.; Lev, B.

    2013-01-01

    Survey evidence suggests that managers voluntarily disclose information, particularly earnings guidance, with an aim toward dampening share price volatility. Yet, consultants and influential institutions advise against providing guidance — citing fears of litigation and market penalties associated w

  17. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  18. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    for the realized volatility series. It emerges that during the recent financial crisis the relative weight of the daily component dominates over the monthly term. The estimates of the two factor stochastic volatility model suggest that the change in the dynamic structure of the realized volatility during...... the financial crisis is due to the increase in the volatility of the persistent volatility term. A set of Monte Carlo simulations highlights the robustness of the methodology adopted in tracking the dynamics of the parameters....

  19. Huntington's disease: review and anesthetic case management.

    Science.gov (United States)

    Cangemi, C F; Miller, R J

    1998-01-01

    Huntington's disease is a dominantly inherited progressive autosomal disease that affects the basal ganglia. Symptoms appear later in life and manifest as progressive mental deterioration and involuntary choreiform movements. Patients with Huntington's disease develop a progressive but variable dementia. Dysphagia, the most significant related motor symptom, hinders nutrition intake and places the patient at risk for aspiration. The combination of involuntary choreoathetoid movements, depression, and apathy leads to cachexia. Factors of considerable concern to the anesthesiologist who treats patients with Huntington's disease may include how to treat frail elderly people incapable of cooperation, how to treat patients suffering from malnourishment, and how to treat patients with an increased risk for aspiration or exaggerated responses to sodium thiopental and succinylcholine. The successful anesthetic management of a 65-yr-old woman with Huntington's disease who presented for full-mouth extractions is described.

  20. Obstetric use of nitroglycerin: Anesthetic implications

    Science.gov (United States)

    Saroa, Richa; Sachan, Shikha; Palta, Sanjeev; Gombar, Satinder; Sahai, Nitika

    2013-01-01

    Nitroglycerin has been used in anesthetic practice for induced hypotension and managing perioperative hypertension and myocardial ischemia. Contrary to the continuous low dose infusions (5-20 mcg/min) used for the same, intravenous bolus dosages are sometimes administered at the behest of obstetricians for removal of retained placenta. Use of nitroglycerine in managing retained placenta is undertaken as a last resort when other measures fail to relax the uterine smooth muscles. Intravenous nitroglycerine relaxes smooth muscle cells by releasing nitric oxide thus causing prompt cervico-uterine relaxation. However, administration of nitroglycerine in this manner is not without risks which should be kept in mind while using it for obstetric purposes. We hereby report a case of 22-year-old female scheduled for manual removal of placenta where unpredictable and unexpected hypoxemia was observed following nitroglycerine administration. PMID:24015145

  1. Obstetric use of nitroglycerin: Anesthetic implications

    Directory of Open Access Journals (Sweden)

    Richa Saroa

    2013-01-01

    Full Text Available Nitroglycerin has been used in anesthetic practice for induced hypotension and managing perioperative hypertension and myocardial ischemia. Contrary to the continuous low dose infusions (5-20 mcg/min used for the same, intravenous bolus dosages are sometimes administered at the behest of obstetricians for removal of retained placenta. Use of nitroglycerine in managing retained placenta is undertaken as a last resort when other measures fail to relax the uterine smooth muscles. Intravenous nitroglycerine relaxes smooth muscle cells by releasing nitric oxide thus causing prompt cervico-uterine relaxation. However, administration of nitroglycerine in this manner is not without risks which should be kept in mind while using it for obstetric purposes. We hereby report a case of 22-year-old female scheduled for manual removal of placenta where unpredictable and unexpected hypoxemia was observed following nitroglycerine administration.

  2. Renal effects of methoxyverapamil in anesthetized rats.

    Science.gov (United States)

    Brown, B; Churchill, P

    1983-05-01

    The purpose of these experiments was to determine the renal effects of methoxyverapamil (D-600). Three groups of rats were anesthetized with sodium pentobarbital and given 0, 0.85 or 1.69 nmol/min of methoxyverapamil i.v. Increases in urine flow and Na, K and Ca excretory rates occurred, in an apparently dose-dependent manner. Plasma Na and arterial renin concentration decreased at both doses and, at the higher dose, mean arterial blood pressure and effective renal plasma flow decreased while plasma K increased. Plasma Ca, glomerular filtration rate, filtration fraction and total renal plasma flow were not affected. The findings that methoxyverapamil increased urine flow and electrolyte excretion without changing glomerular filtration rate are consistent with the hypothesis that methoxyverapamil acts directly on tubular reabsorptive mechanisms. These effects, and the effect on plasma renin concentration, could contribute to the beneficial effects of this and other Ca entry antagonists in the treatment of hypertension.

  3. Location of the Mesopontine Neurons Responsible for Maintenance of Anesthetic Loss of Consciousness.

    Science.gov (United States)

    Minert, Anne; Yatziv, Shai-Lee; Devor, Marshall

    2017-09-20

    The transition from wakefulness to general anesthesia is widely attributed to suppressive actions of anesthetic molecules distributed by the systemic circulation to the cerebral cortex (for amnesia and loss of consciousness) and to the spinal cord (for atonia and antinociception). An alternative hypothesis proposes that anesthetics act on one or more brainstem or diencephalic nuclei, with suppression of cortex and spinal cord mediated by dedicated axonal pathways. Previously, we documented induction of an anesthesia-like state in rats by microinjection of small amounts of GABAA-receptor agonists into an upper brainstem region named the mesopontine tegmental anesthesia area (MPTA). Correspondingly, lesioning this area rendered animals resistant to systemically delivered anesthetics. Here, using rats of both sexes, we applied a modified microinjection method that permitted localization of the anesthetic-sensitive neurons with much improved spatial resolution. Microinjected at the MPTA hotspot identified, exposure of 1900 or fewer neurons to muscimol was sufficient to sustain whole-body general anesthesia; microinjection as little as 0.5 mm off-target did not. The GABAergic anesthetics pentobarbital and propofol were also effective. The GABA-sensitive cell cluster is centered on a tegmental (reticular) field traversed by fibers of the superior cerebellar peduncle. It has no specific nuclear designation and has not previously been implicated in brain-state transitions.SIGNIFICANCE STATEMENT General anesthesia permits pain-free surgery. Furthermore, because anesthetic agents have the unique ability to reversibly switch the brain from wakefulness to a state of unconsciousness, knowing how and where they work is a potential route to unraveling the neural mechanisms that underlie awareness itself. Using a novel method, we have located a small, and apparently one of a kind, cluster of neurons in the mesopontine tegmentum that are capable of effecting brain-state switching

  4. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences.

    Science.gov (United States)

    Trindade-Suedam, Ivy Kiemle; Gaia, Bruno Felipe; Cheng, Cheong Kuo; Trindade, Paulo Alceu Kiemle; Bastos, José Carlos da Cunha; Mattos, Beatriz Silva Câmara

    2012-02-01

    Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1) to describe changes in the innervation pattern of anterior teeth and soft tissue caused by the presence of a cleft, 2) to describe a local anesthetic procedure in unilateral and bilateral clefts, and 3) to provide recommendations to improve anesthetic procedures in patients with cleft lip and palate. The cases of 2 patients are presented: one with complete unilateral cleft lip and palate, and the other with complete bilateral cleft lip and palate. The patients underwent local anesthesia in the cleft area in order to extract teeth with poor bone support. The modified anesthetic procedure, respecting the altered course of nerves in the cleft maxilla and soft tissue alterations at the cleft site, was accomplished successfully and the tooth extraction was performed with no pain to the patients. General dentists should be aware of the anatomic variations in nerve courses in the cleft area to offer high quality treatment to patients with cleft lip and palate.

  5. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences

    Directory of Open Access Journals (Sweden)

    Ivy Kiemle Trindade-Suedam

    2012-02-01

    Full Text Available Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1 to describe changes in the innervation pattern of anterior teeth and soft tissue caused by the presence of a cleft, 2 to describe a local anesthetic procedure in unilateral and bilateral clefts, and 3 to provide recommendations to improve anesthetic procedures in patients with cleft lip and palate. The cases of 2 patients are presented: one with complete unilateral cleft lip and palate, and the other with complete bilateral cleft lip and palate. The patients underwent local anesthesia in the cleft area in order to extract teeth with poor bone support. The modified anesthetic procedure, respecting the altered course of nerves in the cleft maxilla and soft tissue alterations at the cleft site, was accomplished successfully and the tooth extraction was performed with no pain to the patients. General dentists should be aware of the anatomic variations in nerve courses in the cleft area to offer high quality treatment to patients with cleft lip and palate.

  6. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  7. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline......-based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness....

  8. Option Valuation with Observable Volatility and Jump Dynamics

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jeon, Yoontae

    Under very general conditions, the total quadratic variation of a jump-diffusion process can be decomposed into diffusive volatility and squared jump variation. We use this result to develop a new option valuation model in which the underlying asset price exhibits volatility and jump intensity dy...

  9. Effect of Lidocaine-Ketamine Infusions Combined with Morphine or Fentanyl in Sevoflurane-Anesthetized Pigs.

    Science.gov (United States)

    Re, Michela; Canfrán, Susana; Largo, Carlota; Gómez de Segura, Ignacioa A

    2016-01-01

    Providing lidocaine, ketamine, and an opioid greatly decreases the minimum alveolar concentration (MAC) of volatile anesthetics in dogs. However, the efficacy of this combination shows marked interspecies variation, and opioids are likely to be less effective in pigs than in other species. The aim of the study was to determine the effects of constant-rate infusion of lidocaine and ketamine combined with either morphine or fentanyl on the MAC of sevoflurane in pigs. In a prospective, randomized, crossover design, 8 healthy crossbred pigs were premedicated with ketamine and midazolam, and anesthesia was induced and maintained with sevoflurane. Pigs then received ketamine (0.6 mg/kg/h) and lidocaine (3 mg/kg/h) combined with either morphine (0.24 mg/kg/h; MLK) or fentanyl (0.0045 mg/kg/h; FLK) after a loading dose; the control group received Ringers lactate solution. The anesthetic-sparing action of the 2 infusion protocols was calculated according to the MAC, by using dewclaw clamping as the standard noxious stimulus. The sevoflurane MAC (mean ± 1 SD) was 2.0% ± 0.2%, 1.9% ± 0.4%, and 1.8% ± 0.2% in the control, MLK, and FLK groups, respectively. No differences among groups or treatments were found. In conclusion, the administration of MLK or FLK at the studied doses did not reduce the MAC of sevoflurane in pigs.

  10. Effect of Lidocaine–Ketamine Infusions Combined with Morphine or Fentanyl in Sevoflurane-Anesthetized Pigs

    Science.gov (United States)

    Re, Michela; Canfrán, Susana; Largo, Carlota; de Segura, Ignacio A Gómez

    2016-01-01

    Providing lidocaine, ketamine, and an opioid greatly decreases the minimum alveolar concentration (MAC) of volatile anesthetics in dogs. However, the efficacy of this combination shows marked interspecies variation, and opioids are likely to be less effective in pigs than in other species. The aim of the study was to determine the effects of constant-rate infusion of lidocaine and ketamine combined with either morphine or fentanyl on the MAC of sevoflurane in pigs. In a prospective, randomized, crossover design, 8 healthy crossbred pigs were premedicated with ketamine and midazolam, and anesthesia was induced and maintained with sevoflurane. Pigs then received ketamine (0.6 mg/kg/h) and lidocaine (3 mg/kg/h) combined with either morphine (0.24 mg/kg/h; MLK) or fentanyl (0.0045 mg/kg/h; FLK) after a loading dose; the control group received Ringers lactate solution. The anesthetic-sparing action of the 2 infusion protocols was calculated according to the MAC, by using dewclaw clamping as the standard noxious stimulus. The sevoflurane MAC (mean ± 1 SD) was 2.0% ± 0.2%, 1.9% ± 0.4%, and 1.8% ± 0.2% in the control, MLK, and FLK groups, respectively. No differences among groups or treatments were found. In conclusion, the administration of MLK or FLK at the studied doses did not reduce the MAC of sevoflurane in pigs. PMID:27177566

  11. The anesthetic effect of alcohols and alkanes in caenorhabditis elegans (C. E. )

    Energy Technology Data Exchange (ETDEWEB)

    Anton, A.H.; Berk, A.I.; Nicholls, C.H. (Case Western Reserve Univ., Cleveland, OH (United States))

    1991-03-11

    The authors colleagues reported that the non-parasitic roundworm, C.E., was reversibly immobilized by volatile anesthetics, whose potencies were directly related to their lipid solubilities as in other animals. In further studies on this phenomenon, they tested a homologous series of organic solvents, to determine whether they also had a reversible anesthetic effect in C.E. as in other animals. Synchronized 3-1/2 day-old cultures of about 100 worms each were exposed to increasing concentrations of the alcohols (C{sub 1} - C{sub 14}) and alkanes (C{sub 5} -C{sub 10}) in 15 ml sealed bottles in a volume of 0.5 ml. The dose that reversibly immobilized 50% of the worms was determined and a straight line was plotted against the octanol/water partition coefficient (K) of each series. As with other animals, potency was directly related to the lipid solubility of these agents so that, for example, the ID{sub 50} for methanol was 1,000 mmol (K=0.12) whereas it was 0.17 mmol for heptanol (K=3,000). The alcohols were about 20 times more potent than the alkanes even though the latter were about 10 times more lipid soluble than the alcohols. In spite of these differences, the cut-off point was at C{sub 9} in the two series.

  12. The Role of Implied Volatility in Forecasting Future Realized Volatility and Jumps in Foreign Exchange, Stock and Bond Markets

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper

    We study the forecasting of future realized volatility in the stock, bond, and foreign exchange markets, as well as the continuous sample path and jump components of this, from variables in the information set, including implied volatility backed out from option prices. Recent nonparametric...... statistical techniques are used to separate realized volatility into its continuous and jump components, thus enhancing forecasting performance as shown by Andersen et al. (2005). We generalize the heterogeneous autoregressive (HAR) model to include implied volatility as an additional regressor...

  13. Anesthetic implications for video assisted thoracoscopic thymectomy in myasthenia gravis.

    Science.gov (United States)

    El-Dawlatly, Abdelazeem A; Al Kattan, Khaled; Hajjar, Waseem; Essa, Mohamed; Delvi, Bilal; Khoja, Abdulaziz

    2005-06-01

    Thymectomy is an established therapy in the management of generalized myasthenia gravis (MG). However, the optimal surgical approach to thymectomy has remained controversial. There are advocates for transternal, transcervical approaches for "maximal" thymectomy. Video-assisted thoracoscopic thymectomy (VATT) presents new approach to thymectomy. By minimizing chest wall trauma, VATT not only causes less postoperative pain, shortens hospital stay, gives better cosmetic results but also leads to wider acceptance by patients for earlier surgery. Anesthesia for thymectomy in MG is challenging. Currently we are using non-muscle relaxant technique (NMRT) which we adopted in 1994, for maximal thymectomy. In this paper, we present our limited experience with two cases of VATT using two different NMRTs. Two cases of MG underwent VATT under general anesthesia (GA) and one lung ventilation (OLV) using double lumen tube (DLT). In both cases NMRT was used which encompass, light GA plus thoracic epidural analgesia (TEA) in one case and without TEA in the other case. We believe that the use of NMRT provides good operative and postoperative conditions. In this report we have described two different NMRTs, one with TEA and the other without. Further studies are needed on large number of cases to establish an anesthetic protocol for VATT.

  14. Anesthetic and surgical complications in 219 cases of myotonic dystrophy.

    Science.gov (United States)

    Mathieu, J; Allard, P; Gobeil, G; Girard, M; De Braekeleer, M; Bégin, P

    1997-12-01

    The objective of this study was to assess the frequency, type, and severity of perioperative complications after a first surgery under general anesthesia in patients with myotonic dystrophy (DM) and to measure the association with suspected risk factors. Numerous cases of perioperative complications in DM patients have been reported. Hazards have been associated with the use of thiopentone, suxamethonium, neostigmine, and halothane. A retrospective study of perioperative complications was conducted for 219 DM patients who had their first surgery under general anesthesia at the Chicoutimi Hospital. The overall frequency of complications was 8.2% (18 of 219). Most complications (16 of 18) were pulmonary, including five patients with acute ventilatory failure necessitating ventilatory support, four patients with atelectasis, and three patients with pneumonia. Using multivariate analysis, we found that the risk of perioperative pulmonary complications (PPC) was significantly higher after an upper abdominal surgery (odds ratio (OR), 24.4; 95% CI, 4.0 to 149.3) and for patients with a severe muscular disability, as assessed by the presence of proximal limb weakness (OR, 14.1; 95% CI, 1.5 to 134.4). The likelihood of PPC was not related to any specific anesthetic drug. Because of the increased risk of PPC, careful monitoring during the early postoperative period, protection of upper airways, chest physiotherapy, and incentive spirometry are mandatory in all symptomatic DM patients, particularly those with a severe muscular disability or those who have undergone an upper abdominal surgery.

  15. A placebo-controlled trial to evaluate an anesthetic gel when probing in patients with advanced periodontitis.

    LENUS (Irish Health Repository)

    Winning, Lewis

    2012-12-01

    The baseline periodontal examination is reported to be a painful dental procedure, but currently there are limited practical techniques to reduce this pain. The objective of this study is to evaluate the efficacy of an intrapocket anesthetic gel in the reduction of pain on periodontal probing in a group of untreated patients with generalized chronic periodontitis (CP).

  16. Oil and stock market volatility: A multivariate stochastic volatility perspective

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Minh, E-mail: minh.vo@metrostate.edu

    2011-09-15

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: > This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. > The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. > The volatility in each market is very persistent. > Innovations that hit either market can affect the volatility in the other market. > The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  17. The Role of Implied Volatility in Forecasting Future Realized Volatility and Jumps in Foreign Exchange, Stock and Bond Markets

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper

    , and to the separate forecasting of the realized components. We also introduce a new vector HAR (VecHAR) model for the resulting simultaneous system, controlling for possible endogeneity issues in the forecasting equations. We show that implied volatility contains incremental information about future volatility......We study the forecasting of future realized volatility in the stock, bond, and foreign exchange markets, as well as the continuous sample path and jump components of this, from variables in the information set, including implied volatility backed out from option prices. Recent nonparametric...... statistical techniques are used to separate realized volatility into its continuous and jump components, thus enhancing forecasting performance as shown by Andersen et al. (2005). We generalize the heterogeneous autoregressive (HAR) model to include implied volatility as an additional regressor...

  18. Pain fiber anesthetic reduces brainstem Fos after tooth extraction.

    Science.gov (United States)

    Badral, B; Davies, A J; Kim, Y H; Ahn, J S; Hong, S D; Chung, G; Kim, J S; Oh, S B

    2013-11-01

    We recently demonstrated that pain-sensing neurons in the trigeminal system can be selectively anesthetized by co-application of QX-314 with the TRPV1 receptor agonist, capsaicin (QX cocktail). Here we examined whether this new anesthetic strategy can block the neuronal changes in the brainstem following molar tooth extraction in the rat. Adult male Sprague-Dawley rats received infiltration injection of anesthetic 10 min prior to lower molar tooth extraction. Neuronal activation was determined by immunohistochemistry for the proto-oncogene protein c-Fos in transverse sections of the trigeminal subnucleus caudalis (Sp5C). After tooth extraction, c-Fos-like immunoreactivity (Fos-LI) detected in the dorsomedial region of bilateral Sp5C was highest at 2 hrs (p tooth extraction; reduced Fos-LI was also observed with the conventional local anesthetic lidocaine. Pulpal anesthesia by infiltration injection was confirmed by inhibition of the jaw-opening reflex in response to electrical tooth pulp stimulation. Our results suggest that the QX cocktail anesthetic is effective in reducing neuronal activation following tooth extraction. Thus, a selective pain fiber 'nociceptive anesthetic' strategy may provide an effective local anesthetic option for dental patients in the clinic.

  19. Can anesthetic treatment worsen outcome in status epilepticus?

    Science.gov (United States)

    Sutter, Raoul; Kaplan, Peter W

    2015-08-01

    Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus".

  20. Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

    2016-01-01

    The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

  1. Anesthetic Management of Direct Laryngoscopy and Dilatation of Subglottic Stenosis in a Patient with Severe Myasthenia Gravis

    Directory of Open Access Journals (Sweden)

    Hesham A. Elsharkawy

    2012-01-01

    Full Text Available We describe the anesthetic management of a patient with severe myasthenia gravis and tracheal stenosis; the patient was scheduled for direct laryngoscopy and dilatation. The combination of myasthenia gravis and tracheal obstruction presents several difficulties for anesthetic management. The airway is shared; therefore, any complications are also shared by the anesthesiologist and bronchoscopists. The potential for respiratory compromise in patients undergoing the two procedures requires that anesthesiologists be familiar with the underlying disease state, as well as the interaction of anesthetic and nonanesthetic drugs in a case involving myasthenia gravis. We reviewed the literature and report our experience in this case. There is no strong evidence for choosing one approach to general anesthesia over another for bronchoscopy. Careful preoperative planning and experience in airway management and jet ventilation are crucial to prevent an adverse outcome and obtain favorable results.

  2. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  3. [Anesthetic management of a patient with 15q tetrasomy for dental treatment].

    Science.gov (United States)

    Hase, Yuri; Kemekura, Nobuhito; Nitta, Yukie; Fujisawa, Toshiaki

    2017-05-23

    15q tetrasomy is a chromosomal abnormality that is a part of the heterogeneous group of extra structurally abnormal chromosomes. This syndrome is characterized by epilepsy, central hypotonia, developmental delay and intellectual disability, and autistic behavior. This is the first report of the anesthetic management of a patient with this syndrome. We administered general anesthesia for dental treatment in a patient with 15q tetrasomy. Appropriate planning for the prevention of complications such as seizures and hypotonia, and for delayed emergence from anesthesia, is required. Specifically, choosing short-acting drugs that do not induce seizures, together with suitable monitoring, resulted in successful anesthetic management of the patient with 15q tetrasomy. Copyright © 2017. Publicado por Elsevier Editora Ltda.

  4. [Body temperature, Aldrete-Kroulik index, and patient discharge from the post-anesthetic recovery unit].

    Science.gov (United States)

    de Castro, Fernanda Salim Ferreira; Peniche, Aparecida de Cássia Giani; Mendoza, Isabel Yovana Quispe; Couto, Andréa Tamancoldi

    2012-08-01

    Patient discharge from post-anesthetic recovery (PAR) depends, among other factors, on normothermia and the patient's score on the Aldrete-Kroulik index. The objective of this study was to verify the relationship between the Aldrete-Kroulik index and body temperature in patients. This study was performed at the University of São Paulo University Hospital. Convenience sampling was used, and the sample consisted of 60 patients of ages between 18 and 60 years who underwent general anesthesia. The patients' body temperature was obtained by tympanic measurement, and the Aldrete-Kroulik index was measured on admission and at discharge from post-anesthetic recovery. The data were processed using SPSS, considering a significance level of 5%, and the Spearman and Wilcoxon tests were applied. In conclusion, no significant correlation was found between the two parameters for discharge.

  5. [Anesthetic management of a Dialysis Patient with Chronic Inflammatory Demyelinating Polyneuropathy].

    Science.gov (United States)

    Takahashi, Yoshihiro; Hara, Koji; Sata, Takeyoshi

    2015-11-01

    We report the successful management of anesthesia in a 46-year-old male dialysis patient with chronic inflammatory demyelinating polyneuropathy (CIDP). He underwent an osteosynthesis of the ankle joint using general anesthesia combined with epidural anesthesia. The anesthetic concerns in patients with CIDP are the possibility of postoperative respiratory dysfunction due to anesthetics or muscle relaxants and that of postoperative neurological deterioration due to spinal or epidural anesthesia. In this case, sevoflurane (1.5-2%) did not cause respiratory dysfunction postoperatively and muscle relaxant effect of rocuronium was effectively reversed by sugammadex. Epidural anesthesia using ropivacaine (0.2-0.375%) and fentanyl did not worsen the neurological symptoms of CIDP post-operatively.

  6. Local anesthetics: dentistry's most important drugs, clinical update 2006.

    Science.gov (United States)

    Malamed, Stanley F

    2006-12-01

    Local anesthetics are the safest most effective drugs in medicine for the control and management of pain. They also represent the most important drugs in dentistry. Today, dentistry has a spectrum of local anesthetics that permit pain control to be tailored to the specific needs of the patient: short-, intermediate-, and long-acting drugs. Bupivacaine has become a standard part of the armamentarium for postsurgical pain control while articaine has become the second-most used local anesthetic in the United States since its introduction in 2000. Despite an increase in anecdotal reports of paresthesia since articaine's introduction there is yet, no supporting scientific evidence.

  7. Comparison of anesthetic agents in the sea otter

    Energy Technology Data Exchange (ETDEWEB)

    Williams, T.D.; Kocher, F.H.

    1978-01-01

    Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

  8. Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

    Science.gov (United States)

    Bayuse, T.; Law, J.; Alexander, D.; Moynihan, S.; LeBlanc, C.; Langford, K.; Magalhaes, L.

    2015-01-01

    On orbit, ophthalmic anesthetics are used for tonometry and off-nominal corneal examinations. Proparacaine has been flown traditionally. However, the manufacturers recently changed its storage requirements from room temperature storage to refrigerated storage to preserve stability and prolong the shelf-life. Since refrigeration on orbit is not readily available and there were stability concerns about flying proparacaine unrefrigerated, tetracaine was selected as an alternative ophthalmic anesthetic in 2013. We will discuss the challenges encountered flying and using these anesthetics on the International Space Station.

  9. Anesthetic drug wastage in the operation room: A cause for concern

    Directory of Open Access Journals (Sweden)

    Kapil Chaudhary

    2012-01-01

    Full Text Available Context: The cost of anesthetic technique has three main components, i.e., disposable supplies, equipments, and anesthetic drugs. Drug budgets are an easily identifiable area for short-term savings. Aim: To assess and estimate the amount of anesthetic drug wastage in the general surgical operation room. Also, to analyze the financial implications to the hospital due to drug wastage and suggest appropriate steps to prevent or minimize this wastage. Settings and Design: A prospective observational study conducted in the general surgical operation room of a tertiary care hospital. Materials and Methods: Drug wastage was considered as the amount of drug left unutilized in the syringes/vials after completion of a case and any ampoule or vial broken while loading. An estimation of the cost of wasted drug was made. Results: Maximal wastage was associated with adrenaline and lignocaine (100% and 93.63%, respectively. The drugs which accounted for maximum wastage due to not being used after loading into a syringe were adrenaline (95.24%, succinylcholine (92.63%, lignocaine (92.51%, mephentermine (83.80%, and atropine (81.82%. The cost of wasted drugs for the study duration was 46.57% (Rs. 16,044.01 of the total cost of drugs issued/loaded (Rs. 34,449.44. Of this, the cost of wastage of propofol was maximum being 56.27% (Rs. 9028.16 of the total wastage cost, followed by rocuronium 17.80% (Rs. 2856, vecuronium 5.23% (Rs. 840, and neostigmine 4.12% (Rs. 661.50. Conclusions: Drug wastage and the ensuing financial loss can be significant during the anesthetic management of surgical cases. Propofol, rocuronium, vecuronium, and neostigmine are the drugs which contribute maximally to the total wastage cost. Judicious use of these and other drugs and appropriate prudent measures as suggested can effectively decrease this cost.

  10. Induction of burst suppression or coma using intravenous anesthetics in refractory status epilepticus.

    Science.gov (United States)

    Kang, Bong Su; Jung, Keun-Hwa; Shin, Jeong-Won; Moon, Jang Sup; Byun, Jung-Ick; Lim, Jung-Ah; Moon, Hye Jin; Kim, Young-Soo; Lee, Soon-Tae; Chu, Kon; Lee, Sang Kun

    2015-05-01

    General anesthetic-induced coma therapy has been recommended for the treatment of refractory status epilepticus (RSE). However, the influence of electroencephalographic (EEG) burst suppression (BS) on outcomes still remains unclear. This study investigated the impact of intravenous anesthetic-induced BS on the prognosis of RSE using a retrospective analysis of all consecutive adult patients who received intravenous anesthetic treatment for RSE at the Seoul National University Hospital between January 2006 and June 2011. Twenty-two of the 111 episodes of RSE were enrolled in this study. Of the 22 RSE patients, 12 (54.5%) were women and 18 (81.4%) exhibited generalized convulsive status epilepticus. Sixteen patients (72.7%) were classified as having acute symptomatic etiology, including three patients with anoxic encephalopathy, and others with remote symptomatic etiology. Only two patients (9.1%) had a favorable Status Epilepticus Severity Score (0-2) at admission. All patients received midazolam (MDZ) as a primary intravenous anesthetic drug for RSE treatment; three (13.6%) received MDZ and propofol, and one (4.5%) received MDZ and pentobarbital. The rates of mortality and poor outcome at discharge were 13.6% (n=3) and 54.5% (n=12), respectively. While BS was achieved in six (27.5%) patients, it was not associated with mortality or poor outcome. Induced BS was associated with prolonged hospital stay in subgroup analysis when excluding anoxic encephalopathy. Our results suggest that induction of BS for treating RSE did not affect mortality or outcome at discharge and may lead to an increased length of hospital stay.

  11. Testing for Co-integration in Vector Autoregressions with Non-Stationary Volatility

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders Christian; Taylor, A. M. Robert

    Many key macro-economic and …nancial variables are characterised by permanent changes in unconditional volatility. In this paper we analyse vector autoregressions with non-stationary (unconditional) volatility of a very general form, which includes single and multiple volatility breaks as special...

  12. Testing for Co-integration in Vector Autoregressions with Non-Stationary Volatility

    DEFF Research Database (Denmark)

    Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

    Many key macro-economic and financial variables are characterised by permanent changes in unconditional volatility. In this paper we analyse vector autoregressions with non-stationary (unconditional) volatility of a very general form, which includes single and multiple volatility breaks as special...

  13. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  14. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  15. Anesthetic considerations for pediatric electroconvulsive therapy.

    Science.gov (United States)

    Franklin, Andrew D; Sobey, Jenna H; Stickles, Eric T

    2017-05-01

    Electroconvulsive therapy is being used more frequently in the treatment of many chronic and acute psychiatric illnesses in children. The most common psychiatric indications for pediatric electroconvulsive therapy are refractory depression, bipolar disorder, schizophrenia, catatonia, and autism. In addition, a relatively new indication is the treatment of pediatric refractory status epilepticus. The anesthesiologist may be called upon to assist in the care of this challenging and vulnerable patient population. Unique factors for pediatric electroconvulsive therapy include the potential need for preoperative anxiolytic and inhalational induction of anesthesia, which must be weighed against the detrimental effects of anesthetic agents on the evoked seizure quality required for a successful treatment. Dexmedetomidine is likely the most appropriate preoperative anxiolytic as oral benzodiazepines are relatively contraindicated. Methohexital, though becoming less available at many institutions, remains the gold standard for induction of anesthesia for pediatric electroconvulsive therapy though ketamine, propofol, and sevoflurane are becoming increasingly viable options. Proper planning and communication between the multidisciplinary teams involved in the care of children presenting for electroconvulsive therapy treatments is vital to mitigating risks and achieving the greatest therapeutic benefit. © 2017 John Wiley & Sons Ltd.

  16. Anesthetic issues for robotic cardiac surgery

    Directory of Open Access Journals (Sweden)

    Wendy K Bernstein

    2015-01-01

    Full Text Available As innovative technology continues to be developed and is implemented into the realm of cardiac surgery, surgical teams, cardiothoracic anesthesiologists, and health centers are constantly looking for methods to improve patient outcomes and satisfaction. One of the more recent developments in cardiac surgical practice is minimally invasive robotic surgery. Its use has been documented in numerous publications, and its use has proliferated significantly over the past 15 years. The anesthesiology team must continue to develop and perfect special techniques to manage these patients perioperatively including lung isolation techniques and transesophageal echocardiography (TEE. This review article of recent scientific data and personal experience serves to explain some of the challenges, which the anesthetic team must manage, including patient and procedural factors, complications from one-lung ventilation (OLV including hypoxia and hypercapnia, capnothorax, percutaneous cannulation for cardiopulmonary bypass, TEE guidance, as well as methods of intraoperative monitoring and analgesia. As existing minimally invasive techniques are perfected, and newer innovations are demonstrated, it is imperative that the cardiothoracic anesthesiologist must improve and maintain skills to guide these patients safely through the robotic procedure.

  17. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock...... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....

  18. Benzocaine-loaded polymeric nanocapsules: study of the anesthetic activities.

    Science.gov (United States)

    De Melo, Nathalie Ferreira Silva; De Araújo, Daniele Ribeiro; Grillo, Renato; Moraes, Carolina Morales; De Matos, Angélica Prado; de Paula, Eneida; Rosa, André Henrique; Fraceto, Leonardo Fernandes

    2012-03-01

    This paper describes a comparison of different polymeric nanocapsules (NCs) prepared with the polymers poly(D,L-lactide-co-glycolide), poly(L-lactide) (PLA), and poly(ε-caprolactone) and used as carrier systems for the local anesthetic (LA) benzocaine (BZC). The systems were characterized and their anesthetic activities investigated. The results showed particle size distributions with polydispersity indices below 0.135, average diameters up to 120 nm, zeta potentials up to -30 mV, and entrapment efficiencies around 70%. Formulations of BZC using the polymeric NCs presented slower release profiles, compared with that of free BZC. Slowest release (release constant, k = 0.0016 min(-1)) was obtained using the PLA NC system. Pharmacological evaluation showed that encapsulation of BZC in PLA NCs prolonged its anesthetic action. This new formulation could potentially be used in future applications involving the gradual release of local anesthetics (LAs).

  19. Anesthetic equipment, facilities and services available for pediatric ...

    African Journals Online (AJOL)

    2011-04-09

    Apr 9, 2011 ... Facilities available for pediatric anesthetic care were service delivery .... life leading to the prevention of psychological trauma in children because of ... to incomplete data on this aspect by a significant number of respondents.

  20. Trigeminal nerve injury associated with injection of local anesthetics

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H.; Ersbøll, Bjarne Kjær

    2011-01-01

    , prilocaine 3 percent, and articaine 4 percent sold in cartridges. Results. The study results showed a highly significant overrepresentation of NSDs associated with articaine 4 percent, in particular with mandibular blocks. Conclusions. The distribution of NSDs was disproportionate to the market share......Background. The authors used comprehensive national registry and clinical data to conduct a study of adverse drug reactions (ADRs), in particular neurosensory disturbance (NSD), associated with local anesthetics used in dentistry. Methods. The study included data sets of annual sales of local...... anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent...

  1. ANESTHETIC MANAGEMENT FOR A PATIENT WITH ACUTE INTERMITTENT PORPHYRIA

    Directory of Open Access Journals (Sweden)

    Nenad Savić

    2010-09-01

    Full Text Available Acute intermittent porphyria is a rare metabolic disorder resulting from a partial deficiency of porphobilinogen deaminase, enzyme in the heme biosynthetic pathway. Its inheritance is autosomal dominant. A deficiency of porphobilinogen deaminase is not sufficient by its self to produce acute intermittent porphyria, and other activating factors must also be present. These include some drugs, hormones, infection, injury and alcohol. Besides others, anesthetics have been implicated in the triggering of a number of severe porphyric reactions. Although there is no clinical evidence, the fear of hypothesized porphyrinogenicity of repetitive anesthetics exposures still remains. Despite these doubts, we report here the case of uneventful repeated exposure to anesthetics in a patient suffering from acute intermittent porphyria, within a fifteen- month period. On both occasions, the patient was safely exposed to certain anesthetics included: propofol, sevoflurane, rocuronium, midazolam and fentanyl.

  2. Cardiovascular effects of tramadol in dogs anesthetized with sevoflurane.

    Science.gov (United States)

    Itami, Takaharu; Tamaru, Naomichi; Kawase, Kodai; Ishizuka, Tomohito; Tamura, Jun; Miyoshi, Kenjirou; Umar, Mohammed A; Inoue, Hiroki; Yamashita, Kazuto

    2011-12-01

    Cardiovascular effects of tramadol were evaluated in dogs anesthetized with sevoflurane. Six beagle dogs were anesthetized twice at 7 days interval. The minimum alveolar concentration (MAC) of sevoflurane was earlier determined in each dog. The dogs were then anesthetized with sevoflurane at 1.3 times of predetermined individual MAC and cardiovascular parameters were evaluated before (baseline) and after an intravenous injection of tramadol (4 mg/kg). The administration of tramadol produced a transient and mild increase in arterial blood pressure (ABP) (P=0.004) with prolonged increase in systemic vascular resistance (SVR) (Ppressure, right atrial pressure and pulmonary capillary wedge pressure. In conclusion, the administration of tramadol produces a prolonged peripheral vascular constriction in dogs anesthetized with sevoflurane, which is accompanied with a transient and mild increase in arterial blood pressure. It also indicated that the degree of vasoconstriction might depend on the plasma concentration of tramadol.

  3. Testing for Co-integration in Vector Autoregressions with Non-Stationary Volatility

    DEFF Research Database (Denmark)

    Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

    Many key macro-economic and financial variables are characterised by permanent changes in unconditional volatility. In this paper we analyse vector autoregressions with non-stationary (unconditional) volatility of a very general form, which includes single and multiple volatility breaks as special...... of volatility is common to, or independent across, the vector of series under analysis. The bootstrap is shown to perform very well in practice....

  4. Interference of anesthetics in blood alcohol analysis by HS-GC-FID: A case report.

    Science.gov (United States)

    Monteiro, C; Proença, P; Tavares, C; Castañera, A; Corte Real, F

    2016-08-01

    One of the techniques most widely used in ethanol analysis in forensic laboratories is undoubtedly the headspace gas chromatography with flame-ionization detection (HS-GC-FID) since the determination of this substance is carried out directly, without the need for additional purification procedures, which leads to increased productivity. This is a very important factor due to the high number of alcohol analysis requested to these laboratories. The presence of other volatile substances can cause a problem given the fact that they can be interferents in ethanol analysis by HS-GC-FID, which can have legal consequences related with driving under the influence of alcohol. The authors report a case of a routine analysis by HS-GC-FID for the determination of ethanol of a driver who has suffered an accident in which the use of two chromatographic columns with different polarities was essential to obtain an unequivocally identification of this substance in presence of an interfering volatile anesthetic administered in the hospital. The method was validated according to international recommendations before being introduced into routine laboratory in terms of selectivity, limits of detection (LOD), limits of quantification (LOQ), linearity, repeatability, intermediate precision, accuracy, robustness and carryover.

  5. Severe preeclampsia: anesthetic implications of the disease and its management.

    Science.gov (United States)

    Turner, Judi A

    2009-01-01

    Preeclampsia is a significant, multifactorial, multiorgan disease affecting 6%-8% of all pregnancies in the United States and is the third leading cause of maternal mortality. As such, it is incumbent upon any anesthesia provider involved in obstetric cases to be familiar with the varied manifestations of the disease, management goals from an obstetric standpoint, and the implications for provision of anesthesia in this patient group. Despite improvements in the diagnosis and management of preeclampsia, severe complications can occur in both the mother and the fetus. A systematic approach to the anesthetic evaluation is therefore necessary to reduce morbidity and mortality and to improve outcomes. The potential pitfalls of general anesthesia, including failed intubation, in these complicated patients make regional anesthesia the preferred choice in many cases. Recent studies have shown that spinal anesthesia is often appropriate for preeclamptic patients, even in severe cases. Nevertheless, it is important to be aware of the potential contraindications to neuraxial anesthesia and to prepare for the possibility of encountering a difficult airway.

  6. Anesthetic management of a patient with multiple sclerosis - case report

    Directory of Open Access Journals (Sweden)

    Eduardo Barbin Zuccolotto

    Full Text Available Abstract Background and objectives: Multiple sclerosis is a demyelinating disease of the brain and spinal cord, characterized by muscle weakness, cognitive dysfunction, memory loss, and personality disorders. Factors that promote disease exacerbation are stress, physical trauma, infection, surgery, and hyperthermia. The objective is to describe the anesthetic management of a case referred to urological surgery. Case report: A female patient, 44 years of age, with multiple sclerosis, diagnosed with nephrolithiasis, referred for endoscopic ureterolythotripsy. Balanced general anesthesia was chosen, with midazolam, propofol and remifentanil target-controlled infusion; sevoflurane via laryngeal mask airway; and spontaneous ventilation. Because the patient had respiratory difficulty presenting with chest wall rigidity, it was decided to discontinue the infusion of remifentanil. There was no other complication or exacerbation of disease postoperatively. Conclusion: The use of neuromuscular blockers (depolarizing and non-depolarizing is a problem in these patients. As there was no need for muscle relaxation in this case, muscle relaxants were omitted. We conclude that the combination of propofol and sevoflurane was satisfactory, not resulting in hemodynamic instability or disease exacerbation.

  7. Congenital lobar emphysema: A modified approach to anesthetic management

    Directory of Open Access Journals (Sweden)

    Malathi C Nandihalli

    2015-01-01

    Full Text Available Congenital lobar emphysema (CLE is a potentially reversible, though life-threatening cause of respiratory distress in neonates. It is a rare developmental anomaly of the lower respiratory tract. A 10-month-old child presented with fever, cough and difficulty in breathing. Respiratory system examination revealed tachypnea with intercostal retraction, decreased breath sounds over the left upper lobe and room air saturation of 95%. Chest radiograph and computed tomography showed hyperinflated left upper zones with mediastinal shift. Left thoracotomy, followed by left upper lobectomy was performed under general anesthesia with one lung ventilation. Oxygen saturation, blood pressure, electrocardiogram and capnogram were continuously monitored. During anesthesia, conventionally positive pressure ventilation is avoided until the diseased lobe is isolated, however we adopted gentle manual ventilation maintaining the airway pressure before thoracotomy as described by Cotι and Payne et al. Successful anesthetic management of CLE can be achieved by proper understanding of pathophysiology, good perioperative monitoring, and adopting novel management strategies.

  8. Anesthetic Management of a Patient with Cornelia De Lange Syndrome

    OpenAIRE

    Takeshita, Takahisa; Akita, Susumu; Kawahara, Michio

    1987-01-01

    Cornelia de Lange syndrome presents various problems for anesthetic management, which include anatomical anomalies of face and extremities, cardiopulmonary and endocrine disorders, renal dysfunction, epileptic EEG waves, and mental retardation. The choice of anesthetic procedure must be carefully considered in view of these abnormalities. We administered halothane anesthesia to an 11-year-old child with this syndrome who needed dental treatment. Anesthesia and postoperative course were uneven...

  9. Anesthetic Management of a Patient With Jarcho-Levin Syndrome

    Directory of Open Access Journals (Sweden)

    Gamze Küçükosman

    2016-06-01

    Full Text Available Jarcho-Levin syndrome (JLS is a rare disease involving costovertebral anomalies and is accompanied by hydrocephalus, neural tube defect, and cardiac, renal and gastrointestinal problems. Due to respiratory system pathologies, there is a high mortality rate at young ages. Due to its rarity and little information in the literature related to anesthetic practice for this syndrome, we present our anesthetic experience of inguinal hernia surgery in a patient with JLS.

  10. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process.......In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock...... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  11. Effects of anesthetic compounds on responses of earthworms to electrostimulation.

    Science.gov (United States)

    Podolak-Machowska, Agnieszka; Kostecka, Joanna; Librowski, Tadeusz; Santocki, Michal; Bigaj, Janusz; Plytycz, Barbara

    2014-01-01

    Earthworms play an important role in biomedical research, and some surgical procedures require anesthesia. Anesthetic treatments used so far usually induce convulsive body movements connected with extrusion of coelomocyte-containing coelomic fluid that may affect experimental results. Extensive movements connected with the expulsion of coelomic fluid are exploited by immunologists as a method of harvesting immunocompetent coelomocytes from worms subjected to mild electrostimulation (4.5V). The aim of the investigations was to find anesthetic drugs without unintentional coelomocyte depletion. Experiments were performed on adult specimens of Dendrobaena veneta, the coelomocytes of which consist of amoebocytes and riboflavin-storing eleocytes. Earthworm mobility was filmed and extrusion of coelomocytes was quantified by detection of eleocyte-derived riboflavin in immersion fluid. Treatments included earthworms (1) immersed either in physiological saline (controls) or in a solution of one of the tested anesthetic drugs; (2) electrostimulated immediately after anesthesia, and (3) electrostimulated a second time after a 1-hour recovery period. The well-established fish and amphibian anesthetic agent MS-222 induced coelomocyte expulsion. In contrast, solutions of the mammalian local anesthetic drug, prilocaine hydrochloride (0.25-0.5%, 5-10 min) caused temporal earthworm immobilization followed by recovery, thus showing utility as an efficient earthworm anesthetic.

  12. Effect of local anesthetics on serotonin1A receptor function.

    Science.gov (United States)

    Rao, Bhagyashree D; Shrivastava, Sandeep; Chattopadhyay, Amitabha

    2016-12-01

    The fundamental mechanism behind the action of local anesthetics is still not clearly understood. Phenylethanol (PEtOH) is a constituent of essential oils with a pleasant odor and can act as a local anesthetic. In this work, we have explored the effect of PEtOH on the function of the hippocampal serotonin1A receptor, a representative neurotransmitter receptor belonging to the G protein-coupled receptor (GPCR) family. Our results show that PEtOH induces reduction in ligand binding to the serotonin1A receptor due to lowering of binding affinity, along with a concomitant decrease in the degree of G-protein coupling. Analysis of membrane order using the environment-sensitive fluorescent probe DPH revealed decrease in membrane order with increasing PEtOH concentration, as evident from reduction in rotational correlation time of the probe. Analysis of results obtained shows that the action of local anesthetics could be attributed to the combined effects of specific interaction of the receptor with anesthetics and alteration of membrane properties (such as membrane order). These results assume relevance in the perspective of anesthetic action and could be helpful to achieve a better understanding of the possible role of anesthetics in the function of membrane receptors.

  13. 麻醉药的心脑保护作用:最新临床研究证据及展望%Cardio-neuroprotection of anesthetic agents: recent clinical evidence and perspectives

    Institute of Scientific and Technical Information of China (English)

    李新; 熊利泽

    2015-01-01

    Background The cardio-neuroprotective effect of anesthetics has been widely concerned but still controversial.Although strong preclinical data support that anesthetics could attenuate ischemic/hypoxic myocardial and cerebral injury,confirmative conclusions have not been demonstrated from clinical studies.We reviewed clinical trials in recent years(especially randomized controlled trials) on cardio-neuroprotection of commonly used anesthetic agents (volatile anesthetics:isoflurane,sevoflurane,intravenous anesthetics:propofol,dexmedetomidine).Among the mostly studied anesthetics that reveal the property of cardio-neuroprotection,ether-derived volatile anesthetics have shown more promising potentials than intravenous anesthetics,especially in cardiac surgeries.The cardio-neuroprotection of intravenous anesthetic dexmedetomidine was validated in heart surgery by randomized controlled trial with large sample.However,the neuroprotection of anesthetic agents is controversial,and there's lack of simple and objective evaluation indicators for it.Thus,large-scale,multicenter clinical trials are necessary in the future.%麻醉药的心脑保护作用一直广受关注,但仍存在一些争议.尽管多数临床前研究发现常用麻醉药能减轻缺血/缺氧性心脑损伤,但临床研究却未得到确定性结论.综述近年来关于麻醉药心脑保护作用的临床研究,尤其是随机对照研究,结果表明,多数常用的麻醉药(吸入性麻醉药异氟醚、七氟醚,静脉麻醉药丙泊酚、右美托咪定等)均表现出一定的心脏保护作用,其中氟烷类吸入性麻醉药较静脉麻醉药效果更明显,可显著减轻心脏手术患者的心肌损伤.静脉麻醉药中,右美托咪定对心脏手术患者的心肌保护作用在大样本临床研究中得到验证.麻醉药的脑保护作用存在较大争议,也缺少简单、客观的疗效评价指标,还应开展大规模、多中心的临床研究.

  14. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex...

  15. Differences in motor evoked potentials induced in rats by transcranial magnetic stimulation under two separate anesthetics: implications for plasticity studies

    Directory of Open Access Journals (Sweden)

    Matthew Sykes

    2016-10-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS, a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when

  16. Anesthetics rapidly promote synaptogenesis during a critical period of brain development.

    Directory of Open Access Journals (Sweden)

    Mathias De Roo

    Full Text Available Experience-driven activity plays an essential role in the development of brain circuitry during critical periods of early postnatal life, a process that depends upon a dynamic balance between excitatory and inhibitory signals. Since general anesthetics are powerful pharmacological modulators of neuronal activity, an important question is whether and how these drugs can affect the development of synaptic networks. To address this issue, we examined here the impact of anesthetics on synapse growth and dynamics. We show that exposure of young rodents to anesthetics that either enhance GABAergic inhibition or block NMDA receptors rapidly induce a significant increase in dendritic spine density in the somatosensory cortex and hippocampus. This effect is developmentally regulated; it is transient but lasts for several days and is also reproduced by selective antagonists of excitatory receptors. Analyses of spine dynamics in hippocampal slice cultures reveals that this effect is mediated through an increased rate of protrusions formation, a better stabilization of newly formed spines, and leads to the formation of functional synapses. Altogether, these findings point to anesthesia as an important modulator of spine dynamics in the developing brain and suggest the existence of a homeostatic process regulating spine formation as a function of neural activity. Importantly, they also raise concern about the potential impact of these drugs on human practice, when applied during critical periods of development in infants.

  17. A hypothesis on the origin and evolution of the response to inhaled anesthetics

    OpenAIRE

    Sonner, James M.

    2008-01-01

    An evolutionary narrative explaining why organisms respond to inhaled anesthetics is proposed. It is conjectured that organisms today respond to inhaled anesthetics because their ion channels are sensitive to inhaled anesthetics by virtue of common descent from ancestral, anesthetic-sensitive ion channels in one-celled organisms (i.e., that the response to anesthetics did not arise as an adaptation of the nervous system, but rather of ion channels that preceded the origin of multicellularity)...

  18. Effects of injectable anesthetic combinations on left ventricular function and cardiac morphology in Sprague-Dawley rats.

    Science.gov (United States)

    Sabatini, Carla F; O'Sullivan, M Lynne; Valcour, James E; Sears, William; Johnson, Ron J

    2013-01-01

    Novel anesthetic agents or combinations may provide superior general anesthesia for echocardiography in rodents with the potential for reduced adverse effects. This study sought to characterize the effects of 3 injectable anesthetics on left ventricular (LV) systolic function and cardiac morphology in healthy male and female rats. Rats underwent echocardiographic assessment after general anesthesia via pentobarbital or combinations of ketamine and medetomidine (KME) and ketamine and midazolam (KMI) according to a crossover Latin-square design. Blood samples for serum estradiol measurements were obtained from all females after echocardiography with each anesthetic. Rats given KMI showed superior LV systolic function with the highest values for fractional shortening (FS), ejection fraction (EF) and stroke volume, whereas heart rate was greatest with pentobarbital, followed by KMI and then KME. KME produced the greatest effects on cardiac morphology, most notably during systole, including reduced septal and posterior wall thickness and increased LV chamber dimensions and volumes. In addition, KME had the greatest cardiac-depressing effects on LV systolic function, including reduced FS, EF, and heart rate values. Compared with male rats, female rats had superior LV function with greater EF and FS values, whereas male rats showed higher heart rate. Significant negative correlations were noted between serum estradiol levels and FS and EF values in female rats receiving KME. We conclude that the combination of KMI may be a superior anesthetic for use in male and female rats undergoing echocardiography.

  19. O sevofluorano em psitacídeos (Amazonas aestiva: determinação da dose mínima (d. a. m para produção de anestesia geral Sevoflurane in psitacines (Amazonas aestiva: determination of minimal anesthetic concentration to produce general anesthesia

    Directory of Open Access Journals (Sweden)

    Alexandra Alves Nicolau

    2002-10-01

    Full Text Available Foram utilizados 10 psitacídeos da espécie Amazonas aestiva (papagaio-verdadeiro. Após contenção física, a anestesia foi induzida com o auxílio de uma máscara facial conectada ao sistema de Maplesson D (BARAKA, utilizando sevofluorano a 6V% e fluxo diluente de O2 de 1,5/min de oxigênio. A determinação da Dose Anestésica Mínima (DAM foi estabelecida de maneira similar àquela proposta por LUDDERS et al. (1990. A DAM obtida neste experimento 3,44V%, que eqüivale a concentração alveolar mínima de mamíferos mostrou-se maior nas aves analisadas quando comparada a obtida nos mamíferos. O anestésico mostrou-se bastante seguro para a espécie, não alterando de forma deletéria as variáveis fisiológicas analisadas.Ten adult psittacines (Amazonas aestiva were used. After appropriate immobilization the anesthetic induction was accomplished with facial mask connect to modified circuit of Maggil using 6V% of Sevofluorano with oxygen flow rate at 1.5/. The Minimal Anesthetic Concentration was determined in a manner similar to that proposed by LUDDERS et al. (1990. The MAC obtained was 3.44V%, higher than MAC. proposed to mammals. Sevoflurane can be used safely in avian species once it did not alter significantly all physiological parameters analyzed.

  20. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  1. Plant volatiles and the environment

    NARCIS (Netherlands)

    Loreto, F.; Dicke, M.; Schnitzler, J.P.; Turlings, T.C.J.

    2014-01-01

    Volatile organic compounds emitted by plants represent the largest part of biogenic volatile organic compounds (BVOCs) released into our atmosphere. Plant volatiles are formed through many biochemical pathways, constitutively and after stress induction. In recent years, our understanding of the func

  2. The effect of sub-anesthetic and anesthetic ketamine on water maze memory acquisition, consolidation and retrieval.

    Science.gov (United States)

    Moosavi, Maryam; Yadollahi Khales, Golnaz; Rastegar, Karim; Zarifkar, Asadollah

    2012-02-29

    Ketamine, a non-selective inhibitor of NMDA (N-methyl-D-aspartate) channels is used in anesthetic or sub-anesthetic doses to induce analgesia, amnesia, to suppress fear, anxiety and depression. Although the ketamine's effect on memory acquisition is known, its effects on other aspects of memory are controversial. Morris water maze is a task which assesses spatial learning and memory. This study was aimed to assess the ketamine's differential effect on water maze memory acquisition, consolidation and retrieval. Male Sprague-Dawley rats (250-350 g) were trained in water maze single training session. 24h later a probe trial which was consisted of a single trial without platform was done. To assess the effect of ketamine on water maze memory acquisition it was administered before training; to assess its effect on memory consolidation it was administered immediately after training and to assess its effect on memory retrieval it was injected before probe trial. Ketamine both in sub-anesthetic and anesthetic doses impaired water maze memory acquisition, its anesthetic dose but not sub-anesthetic dose impaired memory consolidation and on retrieval stage, both doses deteriorated memory retrieval. It seems that NMDA receptor activity is not just necessary during water maze memory acquisition but also their post-learning reactivation is required to maintain memory consolidation and retrieval.

  3. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    We include simultaneously both realized volatility measures based on high-frequency asset returns and implied volatilities backed out of individual traded at the money option prices in a state space approach to the analysis of true underlying volatility. We model integrated volatility as a latent...... fi…rst order Markov process and show that our model is closely related to the CEV and Barndorff-Nielsen & Shephard (2001) models for local volatility. We show that if measurement noise in the observable volatility proxies is not accounted for, then the estimated autoregressive parameter in the latent...... process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  4. Return and Volatility Spillovers Among Asian Stock Markets

    Directory of Open Access Journals (Sweden)

    Prashant Joshi

    2011-06-01

    Full Text Available The study examines the return and volatility spillover among Asian stock markets in India, Hong Kong, Japan, China, Jakarta, and Korea using a six-variable asymmetric generalized autoregressive conditional heteroscedasticity–Baba, Engle, Kraft, and Kroner (GARCH-BEKK model during February 2, 2007, to February 29, 2010. The author finds evidence of bidirectional return, shock, and volatility spillover among most of the stock markets. The magnitude of volatility linkages is low indicating weak integration of Asian stock markets. The study finds that own volatility spillover is higher than cross-market spillover. The overall persistence of stock market volatility is highest for Japan (0.931 and lowest for China (0.824. The implication of weak integration is that investors will benefit from reduction of diversifiable risk.

  5. Recognition of local anesthetics by alphabeta+ T cells.

    Science.gov (United States)

    Zanni, M P; von Greyerz, S; Hari, Y; Schnyder, B; Pichler, W J

    1999-02-01

    Patients with drug allergy show a specific immune response to drugs. Chemically nonreactive drugs like, for example, local anesthetics are directly recognized by alphabeta+ T cells in an HLA-DR restricted way, as neither drug metabolism nor protein processing is required for T cell stimulation. In this study we identified some of the structural requirements that determine cross-reactivity of T cells to local anesthetics, with the aim to improve the molecular basis for the selection of alternatives in individuals sensitized to a certain local anesthetic and to better understand presentation and T cell recognition of these drugs. Fifty-five clones (52 lidocaine specific, three mepivacaine specific from two allergic donors) were analyzed. Stimulatory compounds induced a down-regulation of the T cell receptor, demonstrating that these non-peptide antigens are recognized by the T cell receptor itself. A consistent cross-reactivity between lidocaine and mepivacaine was found, as all except one lidocaine specific clone proliferated to both drugs tested. Sixteen chemically related local anesthetics (including ester local anesthetics, OH- and desalkylated metabolites) were used to identify structural requirements for T cell recognition. Each of the four clones examined in detail was uniquely sensitive to changes in the structures of the local anesthetic: clone SFT24, i.e., did not recognize any of the tested OH- or desalkylated metabolites, while the clone OFB2 proliferated to all OH-metabolites and other differently modified molecules. The broadly reactive clone OFB2 allowed us to propose a model, suggesting that the structure of the amine side chain of local anesthetics is essential for recognition by the T cell receptor.

  6. Volatility Nexus Between Stock Market and Macroeconomic Variables in Bangladesh: an Extended GARCH Approach

    Directory of Open Access Journals (Sweden)

    Hasan Md. Abu

    2017-06-01

    Full Text Available This paper examines the volatility of the Bangladesh stock market returns in response to the volatility of the macroeconomic variables employing monthly data of general index of Dhaka Stock Exchange (DSE and four macroeconomic variables (Call Money Rate, Crude Oil Price, Exchange Rate and SENSEX of Bombay Stock Exchange from January 2001 to December 2015. The results of GARCHS models reveal that the volatility of DSE return is significantly guided by the volatility of macroeconomic variables, such as, exchange rate and SENSEX. Specifically, volatility of the DSE is expected to 19% increase by 1% increase of exchange rate. Moreover, the volatility of the Bangladesh stock market returns is expected to dampen down by 2% with an increase in the volatility of Indian stock market of 1%. Thus, we can comment that adding exchange rate or stock returns of India in the GARCH model provides significant knowledge about the behaviour of the DSE volatility.

  7. Clustered volatility in multiagent dynamics

    CERN Document Server

    Youssefmir, M; Youssefmir, Michael; Huberman, Bernardo

    1995-01-01

    Large distributed multiagent systems are characterized by vast numbers of agents trying to gain access to limited resources in an unpredictable environment. Agents in these system continuously switch strategies in order to opportunistically find improvements in their utilities. We have analyzed the fluctuations around equilibrium that arise from strategy switching and discovered the existence of a new phenomenon. It consists of the appearance of sudden bursts of activity that punctuate the fixed point, and is due to an effective random walk consistent with overall stability. This clustered volatility is followed by relaxation to the fixed point but with different strategy mixes from the previous one. This phenomenon is quite general for systems in which agents explore strategies in search of local improvements.

  8. Scaling Foreign Exchange Volatility

    OpenAIRE

    Jonathan Batten; Craig Ellis

    2001-01-01

    When asset returns are normally distributed the risk of an asset over a long return interval may be estimated by scaling the risk from shorter return intervals. While it is well known that asset returns are not normally distributed a key empirical question concerns the effect that scaling the volatility of dependent processes will have on the pricing of related financial assets. This study provides an insight into this issue by investigating the return properties of the most important currenc...

  9. The effect of adenosine triphosphate on sevoflurane requirements for minimum alveolar anesthetic concentration and minimum alveolar anesthetic concentration-awake.

    Science.gov (United States)

    Suzuki, A; Katoh, T; Ikeda, K

    1998-01-01

    We evaluated the effects of i.v. adenosine triphosphate (ATP) on sevoflurane minimum alveolar anesthetic concentration (MAC) and MAC-Awake. The study group included healthy patients 20-60 yr of age. The study groups for MAC-Awake determination included 49 patients who were scheduled for elective surgery. The study groups for MAC determination included 53 patients scheduled for elective surgery involving a skin incision. These patients were randomly assigned to two groups, an ATP group and a control group. The ATP group received 100 micrograms.kg-1.min-1 ATP i.v., and the control group received no medication. The ATP group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) and MAC (anesthetic concentration achieving 50% probability of no movement in response to skin incision). The MAC-Awake was 0.7% +/- 0.1% in the control group (mean +/- SD) and 0.7% +/- 0.1% in the ATP group. MAC was 1.9% +/- 0.1% in the control group and 2.1% +/- 0.2% in the ATP group. The differences in MAC and MAC-Awake between the two groups were not statistically significant. We conclude that ATP infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane MAC and MAC-Awake. We found that an i.v. adenosine triphosphate infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane minimum alveolar anesthetic concentration (anesthetic concentration achieving 50% probability of no movement in response to skin incision) and minimum alveolar anesthetic concentration-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) in humans.

  10. Anesthetic management in a pediatric patient with Noonan syndrome, hypopituitarism and hypothyroidism: A case report

    Directory of Open Access Journals (Sweden)

    Abdulkadir Yektaş

    2013-06-01

    Full Text Available Noonan syndrome is a genetically transmitted autosomaldominant disorder characterized by various anatomicanomalies and pathophysiologic derangements. Associatedanomalies include hyperthelorism, ptosis, micrognathia,downward sloping palpebral fissures, low-set ears,abnormal helix of ear, deeply grooved philtrum, short and/or webbed neck, low hairline and cervical vertebral anomalies.Patients with Noonan syndrome are known to presentwith challenging airways. Tracheal intubation can bedifficult because of airway and cervical vertebral anomaliesand bag mask ventilation may be difficult because ofasymmetrical face. We present a case of anesthetic managementfor Noonan syndrome. J Clin Exp Invest 2013;4 (2: 238-241Key words: Anesthesia, general, noonan syndrome, airwaymanagement

  11. Anesthetic Management of Urgent Cesarean Section with Undiagnosed Transposition of Great Arteries.

    Science.gov (United States)

    Yilmaz, Nurullah; Koksal, Ersin; Ozgen, Gokce Ultan; Ozen, Ersan; Dilek, Ahmet; Karakaya, Deniz; Ulger, Fatma

    2016-06-01

    We consider that general anesthesia will be an appropriate and safe method as regional methods could lead to significant time loss in the prevention or minimization of complications. High blockage required for regional anesthetic methods in pregnant women with TGA and the maintenance of hemodynamic stability may become difficult due to neuroaxial sympathectomy even if a successful neuroaxial block has been provided. Agents with minimal effect on cardiovascular functions should be preferred for anesthesia induction and maintenance and close hemodynamic monitoring should be done during intraoperative and postoperative periods.

  12. Anesthetic management of minimally invasive intervention in children's oncohematology: preoperative patient management protocol

    Directory of Open Access Journals (Sweden)

    V. V. Shchukin

    2013-01-01

    Full Text Available Preoperative patient management protocol in the complex anesthetic support of minimally invasive interventions in pediatric oncology is described. Choice of general anesthesia method was determined by the specific clinical situation by analyzing all of the following factors: airway management, necessity and anticipated duration of unconsciousness, the need for analgesia, necessity and duration of immobilization, prevention of hypothermia, the presence and severity of disturbances in the hemostatic system, comfort for the child and his representatives (parents. Basic techniques of child preoperative examination, as well as the methodology for predicting the risk of perioperative adverse events are described.

  13. Anesthetic management of minimally invasive intervention in children's oncohematology: preoperative patient management protocol

    Directory of Open Access Journals (Sweden)

    V. V. Shchukin

    2014-07-01

    Full Text Available Preoperative patient management protocol in the complex anesthetic support of minimally invasive interventions in pediatric oncology is described. Choice of general anesthesia method was determined by the specific clinical situation by analyzing all of the following factors: airway management, necessity and anticipated duration of unconsciousness, the need for analgesia, necessity and duration of immobilization, prevention of hypothermia, the presence and severity of disturbances in the hemostatic system, comfort for the child and his representatives (parents. Basic techniques of child preoperative examination, as well as the methodology for predicting the risk of perioperative adverse events are described.

  14. Adverse reactions following administration of an ionic iodinated contrast media in anesthetized dogs.

    Science.gov (United States)

    Vance, Amanda; Nelson, Matthew; Hofmeister, Erik H

    2012-01-01

    This retrospective study was conducted to identify hemodynamic alterations associated with the administration of an ionic iodinated contrast media in dogs. Case records of 49 dogs that were anesthetized for computed tomography scanning were reviewed. Values for heart rate (HR) and direct arterial pressure were obtained. Overall, 37% of dogs had a ≥20% change in either HR or systolic arterial pressure from baseline values. Four dogs (8%) became tachycardic and two dogs (4%) became bradycardic. Eight dogs (16%) became hypertensive and two dogs (4%) became hypotensive. A significant proportion of dogs experienced changes in HR and blood pressure following IV administration of an ionic iodinated contrast media under general anesthesia.

  15. The effects of clonidine premedication on sevoflurane requirements and anesthetic induction time.

    Science.gov (United States)

    Inomata, S; Yaguchi, Y; Toyooka, H

    1999-07-01

    We assessed the effects of oral clonidine preanesthetic medication (4.5 microg/kg) on the vital capacity rapid-inhalation anesthetic induction time (VCRII time) and minimum alveolar anesthetic concentration (MAC) to prevent a response to a verbal command in 50% of patients (MAC-Awake) by its hypnotic effect, and on MAC-Skin incision for the analgesic effect in patients anesthetized with sevoflurane. We studied 104 adult patients (control group: n = 52, clonidine group: n = 52) aged 30-48 yr scheduled to undergo general anesthesia. Fifty-two patients received oral clonidine 4.5 microg/kg 1.5 h before arrival in the operating room (clonidine group). The patients exhaled to residual volume and took three vital capacity breaths of 5% sevoflurane in oxygen. The VCRII time was defined as the time interval between the initiation of the VCRII and the disappearance of the response to verbal command. Anesthesia was maintained with sevoflurane in oxygen and air. The end-tidal (ET) sevoflurane concentration reached a predetermined value, then the ratio of predetermined ET to inspiratory concentration was maintained at > or =0.95 for at least 15 min before skin incision. After skin incision, the patients were observed for gross purposeful muscular movements. MAC was defined as the average of the cross-over midpoints in each cross-over. After maintaining the ET sevoflurane concentration for 15 min, patients were judged to be awake or asleep. Average times for VCRII using 5% sevoflurane were achieved in 44+/-11 s (mean +/- SD) and 27+/-6 s in the control and clonidine groups, respectively (P = 0.0001). MAC-Awake values of sevoflurane were 0.66%+/-0.03% and 0.35%+/-0.02% (P = 0.0001), and MAC-Skin incision values were 1.97%+/-0.19% and 1.29%+/-0.13% (P = 0.0001) in the control and clonidine groups, respectively. These results suggest that clonidine may have a more potent hypnotic effect than analgesic effect. Oral clonidine preanesthetic medication (4.5 microg/kg) significantly

  16. Case report: Rhabdomyolysis in morbidly obese patients: anesthetic considerations.

    Science.gov (United States)

    Ankichetty, Saravanan; Angle, Pamela; Margarido, Clarita; Halpern, Stephen H

    2013-03-01

    We report the presentation and management of rhabdomyolysis involving shoulder girdle and upper arm muscles in a morbidly obese patient after prolonged laparoscopic surgery. A 41-yr-old morbidly obese woman presented for laparoscopic abdominal hysterectomy. She had hypertension and type II diabetes which were controlled on regular medications. She also had obstructive sleep apnea. Her clinical examination and investigations revealed no abnormality except morbid obesity (body mass index 54 kg·m(-2)) and left ventricular hypertrophy on transthoracic echocardiogram. Standard general anesthesia was administered under baseline non-invasive monitors. Succinylcholine was used to secure the airway during anesthetic induction. Surgery was performed with the patient positioned with a 15° head-down tilt, and it took six hours to complete the procedure as technical difficulty was encountered due to her body habitus. Her trachea was extubated and she was transferred to the postanesthetic care unit (PACU) without incident. In the PACU, the patient complained of severe bilateral arm pain and weakness an hour after surgery. On physical examination, she exhibited limited movement of her arms against gravity while complaining of tenderness in her shoulder girdle muscles and both arms. Clinical suspicion of rhabdomyolysis based on her signs and symptoms was confirmed by an elevated serum creatinine kinase (CK) of 18,392 IU·L(-1) and serum potassium of 5.3 mmol·L(-1). Intravenous crystalloids and mannitol were administered for 24 hr for renal protection, and her clinical symptoms and serum CK levels improved over seven days. The patient was discharged to home on the tenth postoperative day, and she continued to improve over the three-month follow-up period. Morbidly obese patients who undergo prolonged surgery are at risk for rhabdomyolysis, and early diagnosis and therapy are required to prevent severe complications.

  17. Perioperative anesthetic documentation: Adherence to current Australian guidelines

    Directory of Open Access Journals (Sweden)

    Islam Elhalawani

    2013-01-01

    Full Text Available Purpose: The lack of adequate perioperative documentation has legal implications and can potentially affect the quality and safety of patient care. Despite the presence of guidelines, the adequacy of perioperative documentation in Australasia has not been adequately assessed. The aim of this study is to assess the adequacy of anesthetic documentation on the pre and intraoperative encounters and to test the hypotheses that documentation is incomplete in the settings of emergency vs. elective procedures, regional vs. general anesthesia, and manual vs. electronic documentation. Materials and Methods: The study was an observational retrospective study in the setting of a 250-bed teaching hospital in metropolitan Adelaide, Australia. The perioperative records of 850 patients were analyzed. A scoring system was designed, based on a policy statement from the Australian and New Zealand College of Anesthetists and a survey of the hospital anesthetists. Scored and categorical data was analyzed using Chi-square test. Numerical data was analyzed using student t-test. The null hypothesis was accepted or rejected at 0.05 significance. Results: There were significant deficiencies in the adequacy of preanesthetic and intraoperative records. This has been shown to be true in all cases. Documentation was found to be poorer in the emergency setting when compared to elective cases (median scores 15 vs. 21 P = 0.03 as well as documentation of airway assessment for cases done solely under regional anesthesia (42 vs. 85%, P = 0.05. There were no significant differences in the adequacy of electronic vs. manual records ( P = 0.92. Conclusion: There are significant deficiencies in the adequacy of perioperative records. This has been shown to be true in all cases, but is especially so in emergency cases and for patients having only regional anesthesia.

  18. Towards the development of flexible non-volatile memories.

    Science.gov (United States)

    Han, Su-Ting; Zhou, Ye; Roy, V A L

    2013-10-11

    Flexible non-volatile memories have attracted tremendous attentions for data storage for future electronics application. From device perspective, the advantages of flexible memory devices include thin, lightweight, printable, foldable and stretchable. The flash memories, resistive random access memories (RRAM) and ferroelectric random access memory/ferroelectric field-effect transistor memories (FeRAM/FeFET) are considered as promising candidates for next generation non-volatile memory device. Here, we review the general background knowledge on device structure, working principle, materials, challenges and recent progress with the emphasis on the flexibility of above three categories of non-volatile memories.

  19. Anesthetic Implications of Obesity in the Surgical Patient

    Science.gov (United States)

    Dority, Jeremy; Hassan, Zaki-Udin; Chau, Destiny

    2011-01-01

    The obese patient presents many challenges to both anesthesiologist and surgeon. A good understanding of the pathophysiologic effects of obesity and its anesthetic implications in the surgical setting is critical. The anesthesiologist must recognize increased risks and comorbidities inherent to the obese patient and manage accordingly, optimizing multisystem function in the perioperative period that leads to successful outcomes. Addressed from an organ systems approach, the purpose of this review is to provide surgical specialists with an overview of the anesthetic considerations of obesity. Minimally invasive surgery for the obese patient affords improved analgesia, postoperative pulmonary function, and shorter recovery times at the expense of a more challenging intraoperative anesthetic course. The physiologic effects of laparoscopy are discussed in detail. Although laparoscopy's physiologic effects on various organ systems are well recognized, techniques provide means for compensation and reversing such effects, thereby preserving good patient outcomes. PMID:23204937

  20. Intravenous sub-anesthetic ketamine for perioperative analgesia.

    Science.gov (United States)

    Gorlin, Andrew W; Rosenfeld, David M; Ramakrishna, Harish

    2016-01-01

    Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less) and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine's metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

  1. Intravenous sub-anesthetic ketamine for perioperative analgesia

    Directory of Open Access Journals (Sweden)

    Andrew W Gorlin

    2016-01-01

    Full Text Available Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine′s metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

  2. Multifractal Models, Intertrade Durations and Return Volatility

    OpenAIRE

    Segnon, Mawuli Kouami

    2015-01-01

    This thesis covers the application of multifractal processes in modeling financial time series. It aims to demonstrate the capacity and the robustness of the multifractal processes to better model return volatility and ultra high frequency financial data than both the generalized autoregressive conditional heteroscedasticity (GARCH)-type and autoregressive conditional duration (ACD) models currently used in research and practice. The thesis is comprised of four main parts that ...

  3. PROPOFOL AS AN IMMERSION ANESTHETIC AND IN A MINIMUM ANESTHETIC CONCENTRATION (MAC) REDUCTION MODEL IN GOLDFISH (CARASSIUS AURATUS).

    Science.gov (United States)

    Balko, Julie A; Wilson, Sarah K; Lewbart, Gregory A; Gaines, Brian R; Posner, Lysa P

    2017-03-01

    Propofol is a novel immersion anesthetic in goldfish ( Carassius auratus ). Objectives were to characterize propofol as an anesthetic and assess its suitability in a minimum anesthetic concentration (MAC) reduction model. Using a crossover design, eight goldfish were submerged in 1, 5, or 10 mg/L propofol. Data included induction time, recovery time, heart rate, opercular rate, and response to supramaximal stimulation. Baseline MAC (Dixon's up-and-down method) was determined, and 15 fish were anesthetized with propofol on 4 consecutive days with MAC determination on the fifth day, weekly, for 1 mo. Using a crossover design, MAC of propofol (n = 15) was determined 1 hr following administration of i.m. butorphanol 0.05, 0.5, and 1 mg/kg, dexmedetomidine 0.01, 0.02, and 0.04 mg/kg, ketoprofen 0.5, 1, and 2 mg/kg, morphine 5, 10, and 15 mg/kg, or saline 1 ml/kg. Comparisons were performed with Wilcoxon signed-rank tests (P MAC following daily exposure was 8.4 and 9.0, 8.1, 8.1, and 8.7 mg/L, respectively. MAC reduction was no more than 8% following any drug or dosage. Propofol at 5 and 10 mg/L produced anesthesia, and anesthetic needs were similar following repeated exposure. Propofol was not suitable to test MAC reduction in goldfish in this study.

  4. The Information Content of Treasury Bond Options Concerning Future Volatility and Price Jumps

    DEFF Research Database (Denmark)

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    components. We also introduce a new vector HAR (VecHAR) modelfor the resulting simultaneous system, controlling for possible endogeneity of implied volatility inthe forecasting equations. We show that implied volatility is a biased and inefficient forecast in thebond market. However, implied volatility does...... statisticaltechniques are used to separate realized volatility into its continuous sample path and jumpcomponents, thus enhancing forecasting performance. We generalize the heterogeneous autoregressive(HAR) model to include implied volatility as an additional regressor, and to the separateforecasting of the realized...

  5. Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs Efeitos da infusão intravenosa contínua de fármacos anestésicos ou analgésicos sobre a anestesia geral com isoflurano: Estudo retrospectivo em 200 cães

    Directory of Open Access Journals (Sweden)

    Sofia de Amorim Cerejo

    2013-09-01

    Full Text Available Constant rate infusion (CRI shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran, and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%, 35 (26.3%, and 19 (14.2% dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol % reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl–lidocaine–ketamine CRI groups (pO uso de técnicas de infusão contínua (IC possui inúmeras vantagens na anestesia balanceada, como a redução do requerimento de anestésicos inalatórios e controle da dor. Os fármacos mais comumente utilizados nestes protocolos são os anestésicos locais, dissociativos e opioides, que podem ser administrados isoladamente ou em associações. Foram avaliados os prontuários de 200 cães que foram submetidos a diversos procedimentos cirúrgicos com IC de anest

  6. Anesthetic induction with guaifenesin and propofol in adult horses.

    Science.gov (United States)

    Brosnan, Robert J; Steffey, Eugene P; Escobar, André; Palazoglu, Mine; Fiehn, Oliver

    2011-12-01

    To evaluate whether guaifenesin can prevent adverse anesthetic induction events caused by propofol and whether a guaifenesin-propofol induction combination has brief cardiovascular effects commensurate with rapid drug washout. 8 healthy adult horses. Guaifenesin was administered IV for 3 minutes followed by IV injection of a bolus of propofol (2 mg/kg). Additional propofol was administered if purposeful movement was detected. Anesthesia was maintained for 2 hours with isoflurane or sevoflurane at 1.2 times the minimum alveolar concentration with controlled normocapnic ventilation. Normotension was maintained via a dobutamine infusion. Plasma concentrations of propofol and guaifenesin were measured every 30 minutes. Mean ± SD guaifenesin and propofol doses inducing anesthesia in half of the horses were 73 ± 18 mg/kg and 2.2 ± 0.3 mg/kg, respectively. No adverse anesthetic induction events were observed. By 70 minutes, there was no significant temporal change in the dobutamine infusion rate required to maintain normotension for horses anesthetized with isoflurane or sevoflurane. Mean plasma guaifenesin concentrations were 122 ± 30 μM, 101 ± 33 μM, 93 ± 28 μM, and 80 ± 24 μM at 30, 60, 90, and 120 minutes after anesthetic induction, respectively. All plasma propofol concentrations were below the limit of quantitation. Guaifenesin prevented adverse anesthetic induction events caused by propofol. Guaifenesin (90 mg/kg) followed by propofol (3 mg/kg) should be sufficient to immobilize > 99% of calm healthy adult horses. Anesthetic drug washout was rapid, and there was no change in inotrope requirements after anesthesia for 70 minutes.

  7. PERUBAHAN KOMPONEN VOLATIL SELAMA FERMENTASI KECAP [Change Volatile Components During Soy Sauce Fermentation

    Directory of Open Access Journals (Sweden)

    Anton Apriyantono1

    2004-08-01

    Full Text Available A study has been conducted to investigate changes of volatile components during soy sauce fermentation. During the fermentation, many volatile components produced may contribute to soy sauce flavor. THe volatile identified by GC-MS werw classified into hydrocarbon (15, alcohol (15, aldehyde (14, ester (14, ketone (9, benzene derivative (11, fatty acid (9, furan (5, terpenoid (18, pyrazine (3, thiazole (1, pyridine (1 and sulfur containing compound (2.Concentration of compounds found in almost all fermentation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in raw soybean and their concentration did not change during fermentation. Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linoleic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4 decadienal decreased or undetected during fermentation.The absence of some volatile compounds, e.g. (E-nerolidol and (E,E-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling. Some volatile compounds such as, methyl heptadecanoate and few aromatic alcohols are likely derived from Aspergillus sojae, since these compounds were identified only in 0 day koji

  8. ANESTHETIC CHALLENGES FACED IN A CHILD WITH TREACHER - COLLINS SYNDROME

    Directory of Open Access Journals (Sweden)

    Sahajananda

    2014-01-01

    Full Text Available Anesthesiologists come across pediatric patients with rare diseases and syndromes scheduled for various operative interventions. Treacher Collins syndrome is a rare genetic disorder characterized by craniofacial deformities , the incidence being 1 in 40 , 000 - 70 , 000 births 1 - 3 . Treacher Collins syndrome (TCS poses serious problem in securing and maintaining airway due to facial deformity. Difficulty in intubation increases as the patient’s age increases. It requires meticulous planning and assessment of the airway prior to each anesthetic technique. Here we describe and discuss successful anesthet ic management of an 8 year old boy posted for cana loplasty of the right ear

  9. On changes of measure in stochastic volatility models

    Directory of Open Access Journals (Sweden)

    Bernard Wong

    2006-01-01

    models. This had led many researchers to “assume the condition away,” even though the condition is not innocuous, and nonsensical results can occur if it is in fact not satisfied. We provide an applicable theorem to check the conditions for a general class of Markovian stochastic volatility models. As an example we will also provide a detailed analysis of the Stein and Stein and Heston stochastic volatility models.

  10. Stock Returns Volatility in an Emerging Market: The Pakistani Evidence

    OpenAIRE

    Husain, Fazal; UPPAL, Jamshed

    1999-01-01

    This paper examines stock returns volatility in the Pakistani equity market. Using daily stock prices of 36 companies, 8 sector indices, and the general market index, the AutoRegressive Conditional Heteroscedasticity (ARCH) class of models was applied. The analyses suggest that one of the factors causing high serial dependence in stock returns in the Pakistani equity market is the presence of conditional heteroscedasticity or volatility in stock returns and that even after controlling for vol...

  11. Can children undergoing ophthalmologic examinations under anesthesia be safely anesthetized without using an IV line?

    Directory of Open Access Journals (Sweden)

    Vigoda M

    2011-04-01

    Full Text Available Michael M Vigoda, Azeema Latiff, Timothy G Murray, Jacqueline L Tutiven, Audina M Berrocal, Steven GayerBascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USAPurpose: To document that with proper patient and procedure selection, children undergoing general inhalational anesthesia for ophthalmologic exams (with or without photos, ultrasound, laser treatment, peri-ocular injection of chemotherapy, suture removal, and/or replacement of ocular prosthesis can be safely anesthetized without the use of an intravenous (IV line. Children are rarely anesthetized without IV access placement. We performed a retrospective study to determine our incidence of IV access placement during examinations under anesthesia (EUA and the incidence of adverse events that required intraoperative IV access placement.Methods: Data collected from our operating room (OR information system includes but is not limited to diagnosis, anesthesiologist, surgeon, and location of IV catheter (if applicable, patient’s date of birth, actual procedure, and anesthesia/procedure times. We reviewed the OR and anesthetic records of children (>1 month and <10 years who underwent EUAs between January 1, 2003 and May 31, 2009. We determined the percentage of children who were anesthetized without IV access placement, as well as the incidence of any adverse events that required IV access placement, intraoperatively.Results: We analyzed data from 3196 procedures performed during a 77-month period. Patients’ ages ranged from 1 month to 9 years. Overall, 92% of procedures were performed without IV access placement. Procedure duration ranged from 1–39 minutes. Reasons for IV access placement included parental preference for antinausea medication and/or attending preference for IV access placement. No child who underwent anesthesia without an IV line had an intraoperative adverse event requiring insertion of an IV line.Conclusion: Our data suggest that for

  12. Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane

    Science.gov (United States)

    TOKUSHIGE, Hirotaka; KAKIZAKI, Masashi; ODE, Hirotaka; OKANO, Atsushi; OKADA, Jun; KURODA, Taisuke; WAKUNO, Ai; OHTA, Minoru

    2016-01-01

    ABSTRACT To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (P<0.01) than those in awake horses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported. PMID:27974877

  13. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  14. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate d...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  15. From micro- to nanostructured implantable device for local anesthetic delivery

    Directory of Open Access Journals (Sweden)

    Zorzetto L

    2016-06-01

    Full Text Available Laura Zorzetto,1 Paola Brambilla,1 Elena Marcello,1 Nora Bloise,2 Manuela De Gregori,3 Lorenzo Cobianchi,4,5 Andrea Peloso,4,5 Massimo Allegri,6 Livia Visai,2,7 Paola Petrini1 1Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Milan, 2Department of Molecular Medicine, Centre for Health Technologies (CHT, INSTM UdR of Pavia, University of Pavia, 3Pain Therapy Service, IRCCS Foundation Policlinico San Matteo Pavia, Pavia, 4General Surgery Department, IRCCS Foundation Policlinico San Matteo, Pavia, 5Departments of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, 6Department of Surgical Sciences, University of Parma, Parma, 7Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Lab of Nanotechnology, Pavia, Italy Abstract: Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured

  16. Detection with flash gas chromatography electronic nose of the general influences of glutathione, ascorbic acid, tannin and carbon dioxide treatments on the volatile profiles of white wines of feteasca regala

    Directory of Open Access Journals (Sweden)

    Antoce Arina Oana

    2017-01-01

    Full Text Available The present work aimed to determine some of the influences of the treatments with glutathione (GSH, ascorbic acid (AA, catechinic tannin (T and carbon dioxide (CO2 during winemaking or bottling on the volatile profiles of white wines of Feteasca Regala. The study is based on the use of a flash gas chromatography electronic nose, which is able to discriminate various clusters of wine samples prepared with various combinations of antioxidants. The treatments that induce enough differences in the volatile profiles of the wine that the electronic nose is able to discriminate are likely to be discriminated also by the consumers. When the electronic nose does not discriminate the clusters of samples with certain treatments it is very likely that those treatments are not sufficient to induce a practically important difference in the aromatic profile of wines. The main detectable influences of the antioxidant treatments are presented and discussed. The treatment of musts with AA (50 mg/l clearly influences the volatile profile of the wines, reducing their aromatic complexity. The treatment during bottling with catechinic tannin (20 mg/l does not seem to have an important influence of the profile of the wines produced with the addition of AA and or GSH. The addition of carbon dioxide during bottling does not show much influence one year after bottling, but it shows that in the samples most prone to oxidation, a difference is present. The CO2 treated wines belonging to the cluster of wines treated with 40 mg/l GSH and 50 mg/l AA have distinct profiles, different from those not protected and closer to the clusters of the less oxidised wines. The treatment of musts with GSH shows clear influences at the dose of 40 mg/l, but for the lower dose of 20 mg/l GSH in Feteasca regala wines it is difficult to identify differences compared to the wines included in the cluster of samples not treated with GSH. This finding is particularly relevant as the

  17. Electronic dental anesthesia in a patient with suspected allergy to local anesthetics: report of case.

    Science.gov (United States)

    Malamed, S F; Quinn, C L

    1988-01-01

    A 56-year-old patient with alleged allergy to local anesthetics required restorative dental treatment. Electronic dental anesthesia was used successfully, in lieu of injectable local anesthetics, to manage intraoperative pain associated with the restoration of vital mandibular teeth.

  18. Fentanyl, dexmedetomidine, dexamethasone as adjuvant to local anesthetics in caudal analgesia in pediatrics: A comparative study

    Directory of Open Access Journals (Sweden)

    Elham M. El-Feky

    2015-04-01

    Conclusion: Both caudal dexmedetomidine and caudal dexamethasone added to local anesthetics are good alternatives in prolongation of postoperative analgesia compared to caudal local anesthetic alone or added to caudal fentanyl. Also they showed less side effects compared to caudal fentanyl.

  19. Volatile signals during pregnancy.

    Science.gov (United States)

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment.

  20. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  1. Differential regional metabolism of glucagon in anesthetized pigs

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Kelstrup, Mette; Trebbien, Ramona;

    2003-01-01

    Glucagon metabolism under basal (endogenous) conditions and during intravenous glucagon infusion was studied in anesthetized pigs by use of midregion (M), COOH-terminal (C), and NH2-terminal (N)-RIAs. Arteriovenous concentration differences revealed a negative extraction of endogenous glucagon...

  2. Local anesthetics: New insights into risks and benefits

    NARCIS (Netherlands)

    Lirk, P.

    2014-01-01

    Conventional local anesthetics in contemporary use block the voltage-gated sodium channel by binding to a specific site on the inner facet of the channel pore. Only little fractions of local anaesthetic are thought to participate in nerve blockade, the rest is absorbed into surrounding tissues or th

  3. Anesthetic keratopathy presenting as bilateral Mooren-like ulcers

    Directory of Open Access Journals (Sweden)

    Khakshoor H

    2012-10-01

    Full Text Available Hamid Khakshoor,1 Majid Moshirfar,2 Rachel G Simpson,3 Hamid Gharaee,1 Amir H Vejdani,1 Steven M Christiansen,2 Jason N Edmonds,2 Nicholas L Behunin21Mashhad University of Medical Sciences, Department of Ophthalmology, Mashad, Iran; 2John A Moran Eye Center, University of Utah, Salt Lake City, UT, 3The University of Arizona College of Medicine, Phoenix, AZ, USAAbstract: This observational case report describes the development of bilateral Mooren-like ulcers in a patient with anesthetic keratopathy. A 42-year-old man with a recent history of minor eye trauma and pain self-treated with tetracaine eye drops presented with complaints of acutely worsening vision and severe pain bilaterally. His visual acuity at presentation was limited to hand motion. Slit-lamp examination revealed bilateral epithelial defects at the center of the cornea, and an area of stromal infiltration and thinning with an undermining leading edge resembling a Mooren's ulcer in both eyes. Corneal haze and hypopyon were visible. Anesthetic use was halted immediately and the patient was started on prednisolone and mycophenolate mofetil (Cellcept®, after which visual acuity gradually improved and pain decreased. Despite improvement of symptoms, residual epithelial defects remained, and the patient was ultimately treated with keratoplasty for recovery of vision. We suggest that anesthetic keratopathy should be included in the differential diagnosis for any patient presenting with ring-shaped stromal infiltrates or nonhealing epithelial defects.Keywords: anesthetic abuse, corneal damage, corneal ulceration

  4. The Anesthetic Effect of Anterior Middle Superior Alveolar Technique (AMSA)

    Science.gov (United States)

    de Souza Tolentino, Lívia; Barbisan Souza, André; Girardi, Ana Alice; Romito, Giuseppe Alexandre; Araújo, Maurício Guimarães

    2015-01-01

    Anesthesia of the soft and hard tissues of the maxilla may require up to 5 injections. Thus, the aim of this study was to evaluate the anesthetic efficacy of the anterior middle superior alveolar (AMSA) and supraperiosteal injection techniques during subgingival scaling and root planing (SRP). Thirty individuals with periodontitis were scheduled for SRP on the buccal aspect of teeth in the anterior maxilla. Before SRP, on a randomly chosen side of the maxilla, the supraperiosteal injection was performed in 1 session, while the AMSA injection was conducted in the contralateral side of the same patient in another session. Immediately after each SRP session, patients rated their pain perception during the procedure with a visual analog scale. No statistically significant differences in mean pain ratings during SRP were found after both anesthetic techniques (P > .05). This preliminary study demonstrated that the AMSA and supraperiosteal injection techniques provided similar anesthetic comfort during SRP. The AMSA injection could be an alternative to anesthetize the buccal aspect of maxilla, without the undesirable effects on facial structures such as the upper lip, nostrils, and lower eyelids. However, further randomized clinical trials with larger samples are necessary to confirm such results. PMID:26650493

  5. Comparison of Two Anesthetic Methods for Intravitreal Ozurdex Injection

    Directory of Open Access Journals (Sweden)

    V. Levent Karabaş

    2015-01-01

    Full Text Available Purpose. To determine whether subconjunctival lidocaine injection maintains additional anesthetic effect during intravitreal Ozurdex injection. Methods. 63 patients who were diagnosed as central or branch retinal vein occlusion and planned to receive Ozurdex injection for macular edema were prospectively included in the study. The patients were randomized into one of the two anesthetic groups. The first group received topical proparacaine drop and lidocaine applied pledget. The second group received subconjunctival lidocaine injection in addition to the anesthetics in group 1. Results. Mean pain score was 1.90±2.39 in group 1 and 1.71 ± 2.09 in group 2 (p=0.746. Mean subconjunctival hemorrhage grade was 1.67±0.17 in group 1 and 0.90±0.14 in group 2 (p=0.001. There was no relationship between the amount of subconjunctival hemorrhage and pain score of the patients. Conclusions. There was no difference in pain scores between the two anesthetic methods. The addition of subconjunctival lidocaine injection offered no advantage in pain relief compared to lidocaine-applied pledgets.

  6. ANESTHETIC MANAGEMENT OF A PATIENT WITH SITUS INVERSUS POSTED FOR LAPAROSCOPIC CHOLECYSTECTOMY

    Directory of Open Access Journals (Sweden)

    Sudhir

    2014-04-01

    Full Text Available Situs inversus totalis is a congenital visceral malrotation anomaly that results from disturbances in establishment of left-right asymmetry and it is characterized by total transposition of thoracic and abdominal viscera, and the predicted incidence is one in 10, 000 among the general population. In a patient with situs inversus totalis, not just the diagnosis of any acute abdomen pathology is difficult but equally challenging is the anesthetic management during the respective surgical procedure. We are reporting a patient who had situs inversus totalis and was operated for laparoscopic cholecystectomy under general anesthesia with I-gel, a new supraglottic airway device as an airway conduit. Though the problems related to such patients are mainly of surgical feasibility, an anesthesiologist must be aware of the associated problems of both, situs inversus and the laparoscopy. The present case report lays an emphasis on the potential difficulties during anesthetic management and its various implications. To the best of our knowledge, we report the first case in India of a successful laparoscopic cholecystectomy in a patient with situs inversus totalis with use of I-gel.

  7. Conformation and kinetic characteristics of interactions between local anesthetics and aqueous solutions of hydroxypropylmethylcellulose.

    Science.gov (United States)

    Galenko-Yaroshevskii, A P; Varlashkina, I A; Takhchidi, Kh P; Malyugin, B E; Dukhanin, A S

    2007-05-01

    Conformation and kinetic characteristics of the interactions of local anesthetics lidocaine (xycaine), tetracaine (dicaine), bupivacaine, and new RU-1117 compound with proven anesthetic activity with Visiton (1% hydroxypropylmethylcellulose in phosphate buffer) were studied. It was found that complex formation between the local anesthetics and hydroxypropylmethylcellulose is a time-dependent reversible process. The equilibrium is attained within 2.5-8.0 h and depends on the chemical nature of local anesthetic.

  8. Concentrations of anesthetics across the water-membrane interface; the Meyer-Overton hypothesis revisited

    Science.gov (United States)

    Pohorille, A.; Wilson, M. A.; New, M. H.; Chipot, C.

    1998-01-01

    The free energies of transferring a variety of anesthetic and nonanesthetic compounds across water-oil and water-membrane interfaces were obtained using computer simulations. Anesthetics exhibit greatly enhanced concentrations at these interfaces, compared to nonanesthetics. The substitution of the interfacial solubilites of the anesthetics for their bulk lipid solubilities in the Meyer-Overton relation, was found to give a better correlation, indicating that the potency of an anesthetic is directly proportional to its solubility at the interface.

  9. Stochastic Volatility and Option Pricing in Heath-Jarrow-Morton Term Structure Analysis

    DEFF Research Database (Denmark)

    Skovmand, David

    We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented.......We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented....

  10. Recent developments in volatility modeling and applications

    Directory of Open Access Journals (Sweden)

    A. Thavaneswaran

    2006-01-01

    Full Text Available In financial modeling, it has been constantly pointed out that volatility clustering and conditional nonnormality induced leptokurtosis observed in high frequency data. Financial time series data are not adequately modeled by normal distribution, and empirical evidence on the non-normality assumption is well documented in the financial literature (details are illustrated by Engle (1982 and Bollerslev (1986. An ARMA representation has been used by Thavaneswaran et al., in 2005, to derive the kurtosis of the various class of GARCH models such as power GARCH, non-Gaussian GARCH, nonstationary and random coefficient GARCH. Several empirical studies have shown that mixture distributions are more likely to capture heteroskedasticity observed in high frequency data than normal distribution. In this paper, some results on moment properties are generalized to stationary ARMA process with GARCH errors. Application to volatility forecasts and option pricing are also discussed in some detail.

  11. Anesthetic Management of Pregnant Patients with Appendectomy

    OpenAIRE

    Celik, Feyzi; Oguz, Abdullah; Yildirim, Zeynep Baysal; Guzel, Abdulmenap; Dogan, Erdal; Ciftci, Taner; Aycan, Ilker Onguc

    2014-01-01

    Our goal was to present our anesthesia procedure of pre-diagnosis and laparotomy on pregnant patients with acute appendicitis. After approval Ethics Committee, 77 pregnant patients with a diagnosis of acute appendicitis were evaluated. Patients were separated into two groups: group G (general anesthesia) and Group S (spinal anesthesia), according to the method of anesthesia applied. The patients' age, gestational age, method of anesthesia applied, duration of hospital stay, duration of a...

  12. Trigeminal nerve injury associated with injection of local anesthetics: needle lesion or neurotoxicity?

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H; Ersbøll, Bjarne Kjær

    2011-01-01

    anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent...

  13. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...

  14. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    2009-01-01

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  15. Effects of combined general anesthesia and thoracic epidural ...

    African Journals Online (AJOL)

    2015-11-02

    Nov 2, 2015 ... general anesthesia could dampen stress response to surgical trauma and cause ... anesthetics or opioids, active infection, thoracic vertebra anomaly, and ... Intraoperative muscle relaxation was facilitated by vecuronium.

  16. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  17. Financial crises and volatility spillovers among emerging European equity markets

    Directory of Open Access Journals (Sweden)

    Ugur Ergun

    2014-08-01

    Full Text Available Financial crisis not only have statistically but also economically significant impact on global equity market returns. This study analyzes whether current financial crisis affect the equity market returns of Balkan transition economies and what is the extent of such impact by employing Generalized Autoregressive Conditional Heteroscedasticity model is employed on daily data spans from 2006 to 2012 for three transition economies which are Bosnia-Herzegovina, Croatia and Serbia. Empirical result indicates that volatility of Serbian stock price is influenced by the volatility of Bosnian and Croatian stock prices. There is one way volatility transmission from Bosnian and Croatian stock markets to Serbian stock market. High degree of volatility is observed in the stock markets during latest financial crises.

  18. Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

    DEFF Research Database (Denmark)

    Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

    2017-01-01

    neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...... that propofol is applicable as a general anesthetic in the axolotl allowing for neurophysiological experiments and yielding a stable anesthesia with significantly less cardiovascular effect than both benzocaine and MS-222. Additionally, propofol did not affect gross limb regeneration. In conclusion we suggest...

  19. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  20. Is conformation a fundamental descriptor in QSAR? A case for halogenated anesthetics

    Science.gov (United States)

    Guimarães, Maria C; Duarte, Mariene H; Silla, Josué M

    2016-01-01

    Summary An intriguing question in 3D-QSAR lies on which conformation(s) to use when generating molecular descriptors (MD) for correlation with bioactivity values. This is not a simple task because the bioactive conformation in molecule data sets is usually unknown and, therefore, optimized structures in a receptor-free environment are often used to generate the MD´s. In this case, a wrong conformational choice can cause misinterpretation of the QSAR model. The present computational work reports the conformational analysis of the volatile anesthetic isoflurane (2-chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane) in the gas phase and also in polar and nonpolar implicit and explicit solvents to show that stable minima (ruled by intramolecular interactions) do not necessarily coincide with the bioconformation (ruled by enzyme induced fit). Consequently, a QSAR model based on two-dimensional chemical structures was built and exhibited satisfactory modeling/prediction capability and interpretability, then suggesting that these 2D MD´s can be advantageous over some three-dimensional descriptors. PMID:27340468

  1. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2010-01-01

    The authors examine the advantages of incorporating strategic exposure to equity volatility into the investment opportunity set of a long-term equity investor. They consider two standard volatility investments: implied volatility and volatility risk premium strategies. An analytical framework, which offers pragmatic solutions for long-term investors who seek exposure to volatility, is used to calibrate and assess the risk-return profiles of portfolios. The benefit of volatility exposure for a...

  2. Reduced Heart Rate Volatility

    Science.gov (United States)

    Grogan, Eric L.; Morris, John A.; Norris, Patrick R.; France, Daniel J.; Ozdas, Asli; Stiles, Renée A.; Harris, Paul A.; Dawant, Benoit M.; Speroff, Theodore

    2004-01-01

    Objective: To determine if using dense data capture to measure heart rate volatility (standard deviation) measured in 5-minute intervals predicts death. Background: Fundamental approaches to assessing vital signs in the critically ill have changed little since the early 1900s. Our prior work in this area has demonstrated the utility of densely sampled data and, in particular, heart rate volatility over the entire patient stay, for predicting death and prolonged ventilation. Methods: Approximately 120 million heart rate data points were prospectively collected and archived from 1316 trauma ICU patients over 30 months. Data were sampled every 1 to 4 seconds, stored in a relational database, linked to outcome data, and de-identified. HR standard deviation was continuously computed over 5-minute intervals (CVRD, cardiac volatility–related dysfunction). Logistic regression models incorporating age and injury severity score were developed on a test set of patients (N = 923), and prospectively analyzed in a distinct validation set (N = 393) for the first 24 hours of ICU data. Results: Distribution of CVRD varied by survival in the test set. Prospective evaluation of the model in the validation set gave an area in the receiver operating curve of 0.81 with a sensitivity and specificity of 70.1 and 80.0, respectively. CVRD predict death as early as 24 hours in the validation set. Conclusions: CVRD identifies a subgroup of patients with a high probability of dying. Death is predicted within first 24 hours of stay. We hypothesize CVRD is a surrogate for autonomic nervous system dysfunction. PMID:15319726

  3. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  4. A practical and convenient method for the synthesis of anesthetic drug thiopental: using thiourea and sodium ethoxide

    Directory of Open Access Journals (Sweden)

    Hojat Narimani

    2014-02-01

    Full Text Available A general, simple, practical and convenient method has been described for the synthesis of anesthetic drug thiopental using thiourea in the presence of sodium ethoxide. Anesthetic drug of thiopental was prepared in two stages; during the first stage, the alkylation of mthyl cyanoacetate was performed which was then to be followed by cyclization. Alkylation of methyl cyanoacetate which was performed by 2-iodopentane in the presence of sodium ethoxide reacts with thiourea and then the process was followed by thiopental prepration in excellent yield. Some important aspects of this methodology are the high reactivity of the substrates, avoidance of the use of hazardous solvents, simplicity of the product separation, low cost of the substrates and reagents and high yield of product. This is a applicable and efficient method for the preparation of thiopental anesthesia in high yield and in an appropriate time.

  5. High throughput modular chambers for rapid evaluation of anesthetic sensitivity

    Directory of Open Access Journals (Sweden)

    Eckmann David M

    2006-11-01

    Full Text Available Abstract Background Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. Methods We designed and built a controlled environment apparatus to permit rapid phenotyping of twenty-four mice simultaneously. We used the loss of righting reflex to indicate anesthetic-induced unconsciousness. After fitting the data to a sigmoidal dose-response curve with variable slope, we calculated the MACLORR (EC50, the Hill coefficient, and the 95% confidence intervals bracketing these values. Upon termination of the anesthetic, Emergence timeRR was determined and expressed as the mean ± standard error for each inhaled anesthetic. Results In agreement with several previously published reports we find that the MACLORR of halothane, isoflurane, and sevoflurane in 8–12 week old C57BL/6J mice is 0.79% (95% confidence interval = 0.78 – 0.79%, 0.91% (95% confidence interval = 0.90 – 0.93%, and 1.96% (95% confidence interval = 1.94 – 1.97%, respectively. Hill coefficients for halothane, isoflurane, and sevoflurane are 24.7 (95% confidence interval = 19.8 – 29.7%, 19.2 (95% confidence interval = 14.0 – 24.3%, and 33.1 (95% confidence interval = 27.3 – 38.8%, respectively. After roughly 2.5 MACLORR • hr exposures, mice take 16.00 ± 1.07, 6.19 ± 0.32, and 2.15 ± 0.12 minutes to emerge from halothane, isoflurane, and sevoflurane, respectively. Conclusion This system enabled assessment of inhaled anesthetic responsiveness with a higher precision than that previously reported. It is broadly adaptable for delivering an inhaled therapeutic (or toxin to a population while monitoring its vital signs, motor reflexes, and providing precise control

  6. Stock market volatility using GARCH models: Evidence from South Africa and China stock markets

    OpenAIRE

    Cheteni, Priviledge

    2016-01-01

    This study looks into the relationship between stock returns and volatility in South Africa and China stock markets. A Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model is used to estimate volatility of the stock returns, namely, the Johannesburg Stock Exchange FTSE/JSE Albi index and the Shanghai Stock Exchange Composite Index. The sample period is from January 1998 to October 2014. Empirical results show evidence of high volatility in both the JSE market, and the Shang...

  7. Price Volatility Spillover in Agricultural Markets: An Examination of U.S. Catfish Markets

    OpenAIRE

    Buguk, Cumhur; Hudson, Darren; Hanson, Terrill R.

    2003-01-01

    Price volatility spillovers in the U.S. catfish supply chain are analyzed based on monthly price data from 1980 through 2000 for catfish feed, its ingredients, and farm- and wholesale-level catfish. The exponential generalized autoregressive conditional heteroskedasticity (EGARCH) model was used to test univariate volatility spillovers for prices in the supply chain. Strong price volatility spillover from feeding material (corn, soybeans, menhaden) to catfish feed and farm- and wholesale-leve...

  8. Vibrational Infrared Lifetime of the Anesthetic nitrous oxide gas in solution

    CERN Document Server

    Chieffo, Logan; Shattuck, Jeffrey; Hong, Mi K; Ziegler, Lawrence; Erramilli, Shyamsunder

    2006-01-01

    The lifetime of the asymmetric fundamental stretching 2218 cm$^{-1}$ vibration of the anesthetic gas nitrous oxide (N$_2$O) dissolved in octanol and olive oil is reported. These solvents are model systems commonly used to assess anesthetic potency. Picosecond time-scale molecular dynamics simulations have suggested that protein dynamics or membrane dynamics play a role in the molecular mechanism of anesthetic action. Ultrafast infrared spectroscopy with 100 fs time resolution is an ideal tool to probe dynamics of anesthetic molecules on such timescales. Pump-probe studies at the peak of the vibrational band yield a lifetime of $55 \\pm 1$ ps in olive oil and $52 \\pm 1 ps$ in octanol. The similarity of lifetimes suggests that energy relaxation of the anesthetic is determined primarily by the hydrophobic nature of the environment, consistent with models of anesthetic action. The results show that nitrous oxide is a good model system for probing anesthetic-solvent interactions using nonlinear infrared spectroscop...

  9. Can ultrasound-guided subcostal transverse abdominis plane block be used as sole anesthetic technique?

    Directory of Open Access Journals (Sweden)

    Pooja Bihani

    2017-01-01

    Full Text Available Subcostal transverse abdominis plane (TAP block anesthetizes area of the abdomen with cutaneous innervation of T6–T10 dermatomes. These abdominal field blocks become very advantageous when cardiac patient presents for noncardiac surgeries as sole anesthetic or as a part of multimodal anesthesia. A 58-year-male came for open surgical repair of subxiphoid incisional hernia developed post coronary artery bypass grafting (CABG. Echocardiography showed hypokinesia of left ventricle (LV in the left anterior descending (LAD artery territory, dilated LV, and ejection fraction of 30%, and coronary angiography after 6 months of CABG showed 70% stenosis of LAD. Surgery was successfully accomplished under ultrasound-guided bilateral subcostal TAP block except for a brief period of pain and discomfort when hernia was being reduced which required narcotic supplementation. The patient remained comfortable throughout the procedure as well as 24 h postoperatively without any analgesic supplementation. Thus, subcostal TAP block can be a safe alternative to neuraxial or general anesthesia for epigastric hernia repair in selected patients.

  10. Clinical features and anesthetic management of multiple endocrine neoplasia as sociated with pheochromocytoma

    Institute of Scientific and Technical Information of China (English)

    罗爱伦; 郭向阳; 任洪智; 黄宇光; 叶铁虎

    2003-01-01

    Objective To investigate clinical features and anesthetic management of multiple endocrine neoplasia (MEN) associated with pheochromocytoma.Methods Medical records of patients who were diagnosed as multiple endocrine neoplasia a ssociated with pheochromocytoma in our hospital from April 1977 to April 2001 were reviewed retrospectively. The demographic data, clinical presentations, fami ly history, biochemical examinations, type of MEN, sequence of different surgica l procedures, anesthetic methods and hemodynamics during surgery were analyzed. Results Thirteen cases of MEN associated with pheochromocytoma were investigated, accounting for 6% (13/213) of the pheochromocytoma patients admitted into our hospital. Nine of the 13 patients presented as type Ⅱa MEN (Sipple syndrome), on e as type Ⅱb MEN, and three as mixed MEN. Four patients with typeⅡa MEN had a family history of similar disease. Five patients with other coexisting endocri ne disorders first underwent excision of the pheochromocytomas, although only tw o had hypertensive symptoms at the time of admittance. Seven patients without h istories of hypertension received surgical treatment for pheochromocytoma second ly. The excision of pheochromocytoma was performed under general anesthesia in 8 patients and epidural block in 4 patients. Marked hemodynamic fluctuation was recorded in 8 patients. No perioperative death was recorded. Conclusion Pheochromocytoma may be linked to other endocrine disorders during MEN, either as the main clinical presentation or most frequently as an occult tumor. Recognition of this feature of pheochromocytoma is of importance to the improvement of diagnosis and treatment both for pheochromocytoma and MEN.

  11. [Anesthetic service and the postoperative period in pregnant women with gestosis].

    Science.gov (United States)

    Shepetovskaia, N L; Pivovarova, G M; Volodin, A V; Tolmachev, G N

    2007-01-01

    The paper analyzes the results of using in the anesthetic maintenance of pregnant females with gestosis the algorithm of preventing possible impairments in the development of the general adaptation syndrome in response to pregnancy and surgical labor. Calcium antagonists (eliminating dysfunction of secondary calcium messenger), ketonal, and tranexamic acid (which inhibiting a number of pain and inflammation mediators), and hydroxyethyl starch-130/04 solution (regenerating the endothelium) were administered to prevent the clinical manifestations of the intraabdominal compartment syndrome, ischemia-pefusion, and the second wave of the systemic inflammatory response syndrome in response to surgery. The differential use of the above agents at all stages of anesthetic maintenance in pregnant women with gestosis promoted the postoperative preservation of the most efficient eukinetic hemodynamics and physiological sympathicotonia and the elimination of water metabolic disturbances more early than in the control puerperas. A more physiological postoperative course in the study group puerperas called for much less pharmacotherapy, which created more favorable conditions for postoperative maternal-neonatal contact (feeding, etc.).

  12. Effect of waste anesthetic gas and vapor exposure on reproductive outcome in veterinary personnel

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.A.

    1986-01-01

    This study was designed to investigate potential adverse reproductive outcome in veterinary personnel who are exposed to waste anesthetic gas and vapor at levels near the NIOSH recommended standards. Subjects for this case-control study of births with congenital abnormalities and spontaneous abortion, selected from the American Veterinary Medical Association roster, were contacted by mail and asked to complete a screening questionnaire regarding reproductive history. Crude prevalence rates for spontaneous abortion, births with congenital abnormalities and stillbirths, determined on the basis of the responses to the screening questionnaire, showed no excess rates when compared with national statistics. All pregnancies resulting in spontaneous abortion, stillbirth, or birth with congenital abnormality were selected as cases. Controls were selected from the reported normal births on a stratified random basis to match maternal age and pregnancy number for cases. Occupational exposure to waste anesthetic gas and vapor in general was not found to be significantly associated with adverse reproductive outcome when adjustment was made for radiation exposure. For nitrous oxide exposure, however, an odds ratio significantly greater than one was found for spontaneous abortion among female veterinary assistants and wives of exposed male veterinarians. Use of diagnostic x-rays in veterinary practice was associated with spontaneous abortion in exposed females with a statistically significant dose response effect observed in female veterinarians.

  13. Major morbidity or mortality from office anesthetic procedures: a closed-claim analysis of 13 cases.

    Science.gov (United States)

    Jastak, J T; Peskin, R M

    1991-01-01

    A closed-claim analysis of anesthetic-related deaths and permanent injuries in the dental office setting was conducted in cooperation with a leading insurer of oral and maxillofacial surgeons and dental anesthesiologists. A total of 13 cases occurring between 1974 and 1989 was included. In each case, all available records, reports, depositions, and proceedings were reviewed. The following were determined for each case: preoperative physical status of the patient, anesthetic technique used (classified as either general anesthesia or conscious sedation), probable cause of the morbid event, avoidability of the occurrence, and contributing factors important to the outcome. The majority of patients were classified as American Society of Anesthesiologists (ASA) status II or III. Most patients had preexisting conditions, such as gross obesity, cardiac disease, epilepsy, and chronic obstructive pulmonary disease, that can significantly affect anesthesia care. Hypoxia arising from airway obstruction and/or respiratory depression was the most common cause of untoward events, and most of the adverse events were determined to be avoidable. The disproportionate number of patients in this sample who were at the extremes of age and with ASA classifications below I suggests that anesthesia risk may be significantly increased in patients who fall outside the healthy, young adult category typically treated in the oral surgical/dental outpatient setting.

  14. Efficacy of benzocaine as an anesthetic for salmonid fishes

    Science.gov (United States)

    Gilderhus, P.A.

    1989-01-01

    Benzocaine was tested in the laboratory to determine the effective concentrations for anesthetizing juvenile chinook salmon Oncorhynchus tshawytscha an rainbow trout O. mykiss (formerly Salmo gairdneri ). Tests were conducted at three water temperatures, in waters ranging from very soft to very hard, and with groups of rainbow trout from 5 to 47 cm long and chinook salmon 20 cm long. Effective concentrations were defined as those that rendered the fish fully handleable in 3 min or less, allowed recovery of most fish within 10 min, and caused no mortality after 15-min exposures. Concentrations of 25-45 mg/L anesthetized both species over the entire range of conditions tested. Although efficacy was essentially unrelated to species or water quality, it was related to water temperature and size of fish; the concentrations of benzocaine required were highest at the lowest water temperature and for the largest fish.

  15. Refractometry for quality control of anesthetic drug mixtures.

    Science.gov (United States)

    Stabenow, Jennifer M; Maske, Mindy L; Vogler, George A

    2006-07-01

    Injectable anesthetic drugs used in rodents are often mixed and further diluted to increase the convenience and accuracy of dosing. We evaluated clinical refractometry as a simple and rapid method of quality control and mixing error detection of rodent anesthetic or analgesic mixtures. Dilutions of ketamine, xylazine, acepromazine, and buprenorphine were prepared with reagent-grade water to produce at least 4 concentration levels. The refraction of each concentration then was measured with a clinical refractometer and plotted against the percentage of stock concentration. The resulting graphs were linear and could be used to determine the concentration of single-drug dilutions or to predict the refraction of drug mixtures. We conclude that refractometry can be used to assess the concentration of dilutions of single drugs and can verify the mixing accuracy of drug combinations when the components of the mixture are known and fall within the detection range of the instrument.

  16. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil.

    Science.gov (United States)

    Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

    2017-01-01

    Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing. Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

  17. [Action of a dental anesthetic on cell respiration].

    Science.gov (United States)

    di Jeso, F; Truscello, A; Martinotti, G; Colli, S

    1987-01-01

    It is often required to employ local anesthetics in practising dentistry, particularly when children have to be treated. Our researches on neurotropic drugs in the last years follow our hypothesis that the strong effects on nervous system have always hidden more widespread effects on all tissues and cells. In vitro essays carried out on rat liver mitochondria show that a dental anesthetic, lidocaine, depress respiration coupled to phosphorylation in mitochondria having a good respiratory control; so respiratory control too is depressed, but P/O ratio is unaffected; also respiration uncoupled by 2,4-dinitrophenol is depressed. Depressing respiration cooperates with anesthesia; unchanging P/O is good for the health of the cells and tissues treated by the lidocaine.

  18. Dissociative anesthetic combination reduces intraocular pressure (IOP in rabbits

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    Ewaldo de Mattos-Junior

    2014-02-01

    Full Text Available The aim of this study was evaluate the effects of three anesthetic combinations, ketamine-midazolam, ketamine-xylazine and tiletamine-zolazepam, on IOP in rabbits. In a experimental, blind, randomized, crossover study, six rabbits were anesthetized with each of 3 treatments in random order. Groups KM (ketamine, 30 mg/kg + midazolam, 1 mg/kg; KX (ketamine, 30 mg/kg + xylazine, 3 mg/kg; and TZ (tiletamine + zolazepam, 20 mg/kg. The drugs were mixed in the same syringe injected intramuscularly (IM into the quadriceps muscle. IOP was measured before drug administration (baseline and at 5-minute intervals for 30 minutes. The data were analyzed by a 2-way repeated measures ANOVA followed by Bonferroni test. All groups had significant decreases in IOP compared to baseline (p 0.05. Administration of either ketamine-midazolam, ketamine-xylazine, or tiletamine-zolazepam similarly decrease IOP in rabbits within 30 minutes of injection.

  19. Antidepressants and local anesthetics: drug interactions of interest to dentistry

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    Lea Rosa Chioca

    2010-10-01

    Full Text Available Introduction: Since there is a vast variety of pharmacological treatments for mental conditions, it has been increasingly more common that patients seeking dentistry treatment are continually using psychoactive drugs as antidepressants. The number of people taking antidepressants is increasing; consequently, dentists should update their knowledge on the interaction between this drug class and those used in dental daily practice, such as local anesthetics and vasoconstrictors. Objective: To conduct a literature review on this subject. Literature review and conclusion: Literature data suggest that sympathomimetic vasoconstrictors (epinephrine, norepinephrine, and phenylephrine associated with local anesthetics may potentiate the side effects of antidepressants, particularly tricyclics and MAO inhibitors, on the cardiovascular system. There are few clinical trials and preclinical studies on this subject, and most of them were carried out between the 60s and 80s. Current studies are needed, since many new antidepressant drugs with different mechanisms of action are currently marketed and being used.

  20. Adjuvants to local anesthetics: Current understanding and future trends

    Science.gov (United States)

    Swain, Amlan; Nag, Deb Sanjay; Sahu, Seelora; Samaddar, Devi Prasad

    2017-01-01

    Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by its duration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids (dexamethasone), anti-inflammatory agents (parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action (tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability (liposomal

  1. Anesthetic Management in a Gravida with Type IV Osteogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Elizabeth Vue

    2016-01-01

    Full Text Available Osteogenesis imperfecta (OI is an inherited disorder of the connective tissues caused by abnormalities in collagen formation. OI may present many challenges to the anesthesiologist. A literature review reveals a wide range of implications, from basic positioning to management of the difficult airway. We present the anesthetic management of a 25-year-old gravid woman with OI, fetal demise, and possible uterine rupture, admitted for an exploratory laparotomy.

  2. Infrared image monitoring of local anesthetic poisoning in rats

    OpenAIRE

    Carstens, Angelo Manoel G.; Tambara,Elizabeth Milla; Colman,Daniel; Márcio G. Carstens; Matias, Jorge Eduardo Fouto

    2016-01-01

    Abstract Background and objectives: To evaluate the thermographic predictive value of local anesthetic poisoning in rats that indicates the early recognition of thermal signs of intoxication and enable the immediate start of advanced life support. Methods: Wistar rats underwent intraperitoneal injection of saline and ropivacaine; they were allocated into pairs, and experiments performed at baseline and experimental times. For thermography, central and peripheral compartment were analyzed, c...

  3. Intraperitoneal Local Anesthetic in Pediatric Surgery: A Systematic Review.

    Science.gov (United States)

    Hamill, James K; Rahiri, Jamie-Lee; Liley, Andrew; Hill, Andrew G

    2016-12-01

    Introduction Systematic reviews report intraperitoneal local anesthetic (IPLA) effective in adults but until now no review has addressed IPLA in children. The objective of this review was to answer the question, does IPLA compared with control reduce pain after pediatric abdominal surgery. Materials and Methods Data sources: MEDLINE, EMBASE, Cochrane databases, trials registries, ProQuest, Web of Science, Google Scholar, and Open Gray.

  4. Mechanics and Morphology of Silk Drawn from Anesthetized Spiders

    Science.gov (United States)

    Madsen, B.; Vollrath, F.

    CO2 and N2 anesthetized Nephila spiders produced dragline silk with mechanical properties that differed from control silk as a function of time under anesthesia. Silk from CO2 spiders had a significantly lower breaking strain and breaking energy, significantly higher initial modulus, and marginally lower breaking stress. At the onset of anesthesia the silk diameter became highly variable. During deep anesthesia silk either became thinner or retained cross-section but fibrillated.

  5. ANESTHETIC CONSIDERATION S IN CHRONIC OBSTRUCTIVE PULMON ARY DISEASE

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    Awati

    2015-03-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is a spectrum of diseases that includes emphysema, chronic bronchitis, and small airway disease. It i s characterized by progressive increased resistance to breathing. Patients with marked obstructive pulmonary disease are at increased risk for both intraoperative and Postoperative pulmonary complications. These patients require thorough preoperative prepa ration, meticulous intraoperative management & postoperative care. This article describes anesthetic considerations in a patient with COPD.

  6. Enhanced local anesthetic action of mepivacaine from the bioadhesive gels.

    Science.gov (United States)

    Cho, Cheong-Weon; Choi, Jun-Shik; Shin, Sang-Chul

    2011-01-01

    Mepivacaine, an amide-type local anesthetic, has been used to relieve local pain. Among the many drug delivery systems, transdermal drug delivery has some advantages, as it provides controlled drug delivery for an extended period of time. To develop new gel formulations that have suitable bioadhesion, the bioadhesive force of hydroxypropyl methylcellulose (HPMC) was assessed using an auto-peeling tester. The effect of drug concentration on drug release from 2% HPMC gel was studied using synthetic cellulose membrane at 37±0.5°C. The drug concentrations tested were 0.5, 1, 1.5, 2, and 2.5%. The effect of temperature on drug release from the 2% drug gel was evaluated at 27, 32, 37 and 42°C. To increase the skin permeation of mepivacaine from HPMC gel, enhancers such as saturated and unsaturated fatty acids, pyrrolidones, propylene glycol derivatives, glycerides, and non-ionic surfactants were incorporated into the mepivacaine-HPMC gels. The enhancing effect of the enhancer on drug permeation was then examined in the modified Keshary-Chien cell. For the efficacy study, the anesthetic action of the formulated mepivacaine gel containing enhancer and vasoconstrictor was evaluated with the tail-flick analgesimeter. Among the various kinds of HPMC, HPMC-K100M gel showed the highest viscosity and bioadhesive force. As the viscosity of the HPMC gels increased, the bioadhesive forces increased. Increasing the drug concentration or temperature increased the drug release rate. Among the enhancers used, polyoxyethylene 2-oleyl ether showed the greatest enhancement of permeation. Based on the area under the efficacy curve of the rat tail flick test curve, mepivacaine gel containing polyoxyethylene 2-oleyl ether and tetrahydrozoline showed prolonged and increased local anesthetic action compared to the control. For bioadhesive mepivacaine gels with enhanced local anesthetic action, mepivacaine gels containing penetration enhancer and vasoconstrictor could be developed with the

  7. Volatile cycling and the thermal evolution of planetary mantle

    Science.gov (United States)

    Sandu, Constantin

    degassing/regassing processes, in agreement with more recent estimates. An important effect of the volatile cycling process is a general negative feedback effect that results in a general trend to adjust the mantle volatile content in time to a value set by the energy balance in the system. As a result, the initial amount of volatile in the mantle is rendered irrelevant for late stage of thermal evolution. In the case of no plate tectonics, the opposite effect takes place: initial volatilization plays an important role through entire evolution. The implications of mantle convection on the stability of the lithosphere were investigated further using the thermal history calculations and numeric simulations. They point to the conclusion that mantle convection induced stress levels increase from the past to the present fact that leads to a greater potential of craton deformation. The main consequence of this trend is that sections of continental lithosphere that have remained stable since the Archean and Proterozoic are becoming progressively more prone to instability in the geologically modern era. After the volatiles are degassed from the mantle, they are cycled through the atmosphere. The interact with the climate influencing the surface temperature, and further controlling the mantle convection. Using a grey radiative-convective model for the atmosphere, we analyzed the feedback relationships between volatiles, especially water, and surface temperature. We showed that large amount of water degassed during a hot, possible melt ocean phase after the planet formation could conserve large amount of water in atmosphere and maintain the surface temperature at moderate level.

  8. The bonding of anesthetics and antibiotics on the carboxymethylcellulose

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    Rodić-Grabovac Branka B.

    2007-01-01

    Full Text Available The preparation of biologically active material is one of the most interesting trends in the chemical modification of cellulose. The possibility of obtaining biologically active cellulosic material by sorption of procaine hydrochloride and gentamicin sulphate on CMC was investigated in this paper. The sorption of therapeutics on CMC samples with different degree of substitution was carried out in water solutions of anesthetic and antibiotic, while the desorption was done in 0.95% NaCl solution. The amount of bonded and released therapeutics was determined by UV spe-ctrophotometry. It was found that degree of substitution of car-boxymethylcellulose and concentration of chemotherapeutic water solution have significant influence on the amount of bonded anesthetic and antibiotic. The maximum amount of bonded chemotherapeutic was 72.15 mg of procaine hydrochloride and 165.49 mg of gentamicin sulphate per gram CMC. In both cases the amounts of bonded chemotherape-utics correspond to the concentration of local anesthetic and antibiotic preparation that are used in therapeutic purposes.

  9. Post-anesthetic cortical blindness in cats: twenty cases.

    Science.gov (United States)

    Stiles, J; Weil, A B; Packer, R A; Lantz, G C

    2012-08-01

    The medical records of 20 cats with post-anesthetic cortical blindness were reviewed. Information collected included signalment and health status, reason for anesthesia, anesthetic protocols and adverse events, post-anesthetic visual and neurological abnormalities, clinical outcome, and risk factors. The vascular anatomy of the cat brain was reviewed by cadaver dissections. Thirteen cats were anaesthetised for dentistry, four for endoscopy, two for neutering procedures and one for urethral obstruction. A mouth gag was used in 16/20 cats. Three cats had had cardiac arrest, whereas in the remaining 17 cases, no specific cause of blindness was identified. Seventeen cats (85%) had neurological deficits in addition to blindness. Fourteen of 20 cats (70%) had documented recovery of vision, whereas four (20%) remained blind. Two cats (10%) were lost to follow up while still blind. Ten of 17 cats (59%) with neurological deficits had full recovery from neurological disease, two (12%) had mild persistent deficits and one (6%) was euthanased as it failed to recover. Four cats (23%) without documented resolution of neurological signs were lost to follow up. Mouth gags were identified as a potential risk factor for cerebral ischemia and blindness in cats.

  10. Near-Infrared Spectroscopy for the Evaluation of Anesthetic Depth

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    Gabriela Hernandez-Meza

    2015-01-01

    Full Text Available The standard-of-care guidelines published by the American Society of Anesthesiologists (ASA recommend monitoring of pulse oximetry, blood pressure, heart rate, and end tidal CO2 during the use of anesthesia and sedation. This information can help to identify adverse events that may occur during procedures. However, these parameters are not specific to the effects of anesthetics or sedatives, and therefore they offer little, to no, real time information regarding the effects of those agents and do not give the clinician the lead-time necessary to prevent patient “awareness.” Since no “gold-standard” method is available to continuously, reliably, and effectively monitor the effects of sedatives and anesthetics, such a method is greatly needed. Investigation of the use of functional near-infrared spectroscopy (fNIRS as a method for anesthesia or sedation monitoring and for the assessment of the effects of various anesthetic drugs on cerebral oxygenation has started to be conducted. The objective of this paper is to provide a thorough review of the currently available published scientific studies regarding the use of fNIRS in the fields of anesthesia and sedation monitoring, comment on their findings, and discuss the future work required for the translation of this technology to the clinical setting.

  11. Effect of anesthetics on bending elasticity of lipid membranes

    Science.gov (United States)

    Yi, Zheng; Michihiro, Nagao; Bossev, Dobrin

    2008-03-01

    Change in physical and chemical properties of bio-membranes is of great interest for understanding the mechanism of anesthetic action on membranes. Hypothetically the anesthetic alters the lipid membrane structure (promoting pore formation across membranes or at least switching transmembrane channels) and therefore the biophysical properties of the membrane. We have used neutron spin echo (NSE) spectroscopy to study the effect of anesthetic molecule, lidocaine, on the bending elasticity (BE) of lipid membranes. BE of lipid bilayers made of (1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine) DMPC and 1,2-Dipalmitoyl-sn-Glycero-3-Phosphocholine (DPPC) have been measured at different temperatures and different in the fluid (Lα) phase. Using Zilman-Granek theory the BE were obtained from the decay of the NSE intermediate scattering function. We have found that in the presence of lidocaine the BE of DMPC and DPPC bilayers increases. The results were correlated with those from differential scanning calorimetry. Increase in the lidocaine concentration leads to decrease in the liquid/crystalline transition temperature.

  12. Methylparaben concentration in commercial Brazilian local anesthetics solutions

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    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  13. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Science.gov (United States)

    da SILVA, Gustavo Henrique Rodriguez; BOTTOLI, Carla Beatriz Grespan; GROPPO, Francisco Carlos; VOLPATO, Maria Cristina; RANALI, José; RAMACCIATO, Juliana Cama; MOTTA, Rogério Heládio Lopes

    2012-01-01

    Objective To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. Material and methods Twelve commercial brands (4 in glass and 8 in plastic cartridges) of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo). Separation was performed using high performance liquid chromatography (HPLC) with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v), pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. Results When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v) to 0.16% (m/v). One glass and all plastic cartridges presented methylparaben. Conclusion 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA) and this substance could cause allergic reactions, it is important to alert dentists about its possible presence. PMID:23032206

  14. Neuropathological sequelae of developmental exposure to antiepileptic and anesthetic drugs

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    Chrysanthy eIkonomidou

    2012-08-01

    Full Text Available Glutamate (Glu and aminobutyric acid (GABA are major neurotransmitters in the mammalian brain which regulate brain development at molecular, cellular and systems level. Sedative, anesthetic and antiepileptic drugs interact with glutamate and GABA receptors to produce their desired effects. The question is posed whether such interference with glutamatergic and GABAergic neurotransmission may exert undesired, and perhaps even detrimental effects on human brain development. Preclinical research in rodents and non-human primates has provided extensive evidence that sedative, anesthetic and antiepileptic drugs can trigger suicide of neurons and oligodendroglia, suppress neurogenesis, and inhibit normal synapse development and sculpting. Behavioral correlates in rodents and non-human primates consist of long-lasting cognitive impairment. Retrospective clinical studies in humans exposed to anesthetics or antiepileptic drugs in utero, during infancy or early childhood have delivered conflicting but concerning results in terms of a correlation between drug exposure and impaired neurodevelopmental outcomes. Prospective studies are currently ongoing. This review provides a short overview of the current state of knowledge on this topic.

  15. Anesthetic Efficacy in Irreversible Pulpitis: A Randomized Clinical Trial.

    Science.gov (United States)

    Allegretti, Carlos E; Sampaio, Roberta M; Horliana, Anna C R T; Armonia, Paschoal L; Rocha, Rodney G; Tortamano, Isabel Peixoto

    2016-01-01

    Inferior alveolar nerve block has a high failure rate in the treatment of mandibular posterior teeth with irreversible pulpitis. The aim of this study was to compare the anesthetic efficacy of 4% articaine, 2% lidocaine and 2% mepivacaine, all in combination with 1:100,000 epinephrine, in patients with irreversible pulpitis of permanent mandibular molars during a pulpectomy procedure. Sixty-six volunteers from the Emergency Center of the School of Dentistry, University of São Paulo, randomly received 3.6 mL of local anesthetic as a conventional inferior alveolar nerve block (IANB). The subjective signal of lip numbness, pulpal anesthesia and absence of pain during the pulpectomy procedure were evaluated respectively, by questioning the patient, stimulation using an electric pulp tester and a verbal analogue scale. All patients reported the subjective signal of lip numbness. Regarding pulpal anesthesia success as measured with the pulp tester, the success rate was respectively 68.2% for mepivacaine, 63.6% for articaine and 63.6% for lidocaine. Regarding patients who reported no pain or mild pain during the pulpectomy, the success rate was, respectively 72.7% for mepivacaine, 63.6% for articaine and 54.5% for lidocaine. These differences were not statistically significant. Neither of the solutions resulted in 100% anesthetic success in patients with irreversible pulpitis of mandibular molars.

  16. Interactions of some local anesthetics and alcohols with membranes.

    Science.gov (United States)

    Frangopol, P T.; Mihăilescu, D

    2001-09-01

    A review of the results obtained by our group in the last decade regarding the interactions of procaine, lidocaine, dibucaine and tetracaine with membranes is presented in the context of the literature data. The action upon membranes, in first approximation monomolecular film of stearic acid spread at the air/water interface used as a membrane model, the modification of biomembrane structure and function using diffraction methods, lipid phase transition, fluidity of lipids and proteins, membrane expansion and platelet aggregation were studied. The thermodynamic knowledge of membrane-alcohol interactions improved by using highly sensitive calorimetric techniques are briefly reported. One of the main conclusions is that the physical state of a monolayer model membrane was the result of competitive interactions between film-film and film-substrate interactions. It was taken into account that local anesthetics, such as lidocaine, carbisocaine, mesocaine, showed changes in the bilayer structure, reflected in macroscopic mechanical properties. This restructuring of the lipid bilayer has a significant influence on the operation of functional subunits, e.g. ionic channels formed by gramicidin. The results support the concept of non-specific interactions of local anesthetics with lipid bilayers. The theoretical modeling of the interactions of local anesthetics is closely compared with experimental data. Our new theory of relaxation for these interactions is using a non-archimedean formalism based on a process resulting from superpositions of different component processes which take place at different scales of time.

  17. Medetomidine-ketamine-butorphanol anesthetic combinations in binturongs (Arctictis binturong).

    Science.gov (United States)

    Moresco, Anneke; Larsen, R Scott

    2003-12-01

    The efficacy, safety, and reliability of two ketamine-medetomidine-butorphanol anesthetic combinations were evaluated in 34 adult binturongs (Arctictis binturong). The animals were randomly assigned to one of the two groups. On the basis of estimated body weights, group high ketamine (HK) received ketamine (8 mg/kg, i.m.), medetomidine (0.02 mg/kg, i.m.), and butorphanol (0.2 mg/kg, i.m.) combined in a single injection, and group low ketamine (LK) received ketamine (2 mg/kg, i.m.), medetomidine (0.04 mg/kg, i.m.), and butorphanol (0.2 mg/kg, i.m.). Cardiopulmonary parameters were measured for approximately 45 min; the animals were then administered atipamezole (5 mg/mg medetomidine, i.m.). Individual responses varied greatly to the anesthetic combinations, but similar numbers of animals in each group needed supplemental anesthetic agents (seven in group HK and six in group LK). Mean heart rates were higher in the LK group throughout anesthesia. Animals in both groups were mildly to moderately hypoxemic, but oxygenation improved in both groups following supplemental oxygen administration. Respiratory rates, arterial blood pressures, body temperatures, and end-tidal CO2 values were similar in both groups. Both protocols were effective; however, the LK combination is preferable because the mean recovery time was shorter.

  18. Essays on oil price volatility and irreversible investment

    Science.gov (United States)

    Pastor, Daniel J.

    In chapter 1, we provide an extensive and systematic evaluation of the relative forecasting performance of several models for the volatility of daily spot crude oil prices. Empirical research over the past decades has uncovered significant gains in forecasting performance of Markov Switching GARCH models over GARCH models for the volatility of financial assets and crude oil futures. We find that, for spot oil price returns, non-switching models perform better in the short run, whereas switching models tend to do better at longer horizons. In chapter 2, I investigate the impact of volatility on firms' irreversible investment decisions using real options theory. Cost incurred in oil drilling is considered sunk cost, thus irreversible. I collect detailed data on onshore, development oil well drilling on the North Slope of Alaska from 2003 to 2014. Volatility is modeled by constructing GARCH, EGARCH, and GJR-GARCH forecasts based on monthly real oil prices, and realized volatility from 5-minute intraday returns of oil futures prices. Using a duration model, I show that oil price volatility generally has a negative relationship with the hazard rate of drilling an oil well both when aggregating all the fields, and in individual fields.

  19. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  20. On the Economic Evaluation of Volatility Forecasts

    DEFF Research Database (Denmark)

    Voev, Valeri

    We analyze the applicability of economic criteria for volatility forecast evaluation based on unconditional measures of portfolio performance. The main theoretical finding is that such unconditional measures generally fail to rank conditional forecasts correctly due to the presence of a bias term...... driven by the variability of the conditional mean and portfolio weights. Simulations and a small empirical study suggest that the bias can be empirically substantial and lead to distortions in forecast evaluation. An important implication is that forecasting superiority of models using high frequency...

  1. On forecasting Exchange Rate Volatility.

    OpenAIRE

    Hafner, Christian

    2003-01-01

    In an efficient market, foreign exchange rates have to guarantee absence of triangular arbitrage. This note shows that the no-arbitrage condition can be exploited for forecasting the volatility of a single rate by using the information contained in the other rates. Linearly transforming the volatility forecasts of a bivariate model is shown to be more efficient than using a univariate model for the cross-rate.

  2. Comparison of use of an infrared anesthetic gas monitor and refractometry for measurement of anesthetic agent concentrations.

    Science.gov (United States)

    Ambrisko, Tamas D; Klide, Alan M

    2011-10-01

    To assess agreement between anesthetic agent concentrations measured by use of an infrared anesthetic gas monitor (IAGM) and refractometry. SAMPLE-4 IAGMs of the same type and 1 refractometer. Mixtures of oxygen and isoflurane, sevoflurane, desflurane, or N(2)O were used. Agent volume percent was measured simultaneously with 4 IAGMs and a refractometer at the common gas outlet. Measurements obtained with each of the 4 IAGMs were compared with the corresponding refractometer measurements via the Bland-Altman method. Similarly, Bland-Altman plots were also created with either IAGM or refractometer measurements and desflurane vaporizer dial settings. Bias ± 2 SD for comparisons of IAGM and refractometer measurements was as follows: isoflurane, -0.03 ± 0.18 volume percent; sevoflurane, -0.19 ± 0.23 volume percent; desflurane, 0.43 ± 1.22 volume percent; and N(2)O, -0.21 ± 1.88 volume percent. Bland-Altman plots comparing IAGM and refractometer measurements revealed nonlinear relationships for sevoflurane, desflurane, and N(2)O. Desflurane measurements were notably affected; bias ± limits of agreement (2 SD) were small (0.1 ± 0.22 volume percent) at < 12 volume percent, but both bias and limits of agreement increased at higher concentrations. Because IAGM measurements did not but refractometer measurements did agree with the desflurane vaporizer dial settings, infrared measurement technology was a suspected cause of the nonlinear relationships. Given that the assumption of linearity is a cornerstone of anesthetic monitor calibration, this assumption should be confirmed before anesthetic monitors are used in experiments.

  3. The relationship between trading volumes, number of transactions, and stock volatility in GARCH models

    Science.gov (United States)

    Takaishi, Tetsuya; Chen, Ting Ting

    2016-08-01

    We examine the relationship between trading volumes, number of transactions, and volatility using daily stock data of the Tokyo Stock Exchange. Following the mixture of distributions hypothesis, we use trading volumes and the number of transactions as proxy for the rate of information arrivals affecting stock volatility. The impact of trading volumes or number of transactions on volatility is measured using the generalized autoregressive conditional heteroscedasticity (GARCH) model. We find that the GARCH effects, that is, persistence of volatility, is not always removed by adding trading volumes or number of transactions, indicating that trading volumes and number of transactions do not adequately represent the rate of information arrivals.

  4. Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats.

    Science.gov (United States)

    Spasic, Sladjana; Kalauzi, Aleksandar; Kesic, Srdjan; Obradovic, Milica; Saponjic, Jasna

    2011-11-21

    We used spectral analysis and Higuchi fractal dimension (FD) to correlate the EEG spectral characteristics of the sensorimotor cortex, hippocampus, and pons with their corresponding EEG signal complexities in anesthetized rats. We have explored the quantitative relationship between the mean FDs and EEG wide range high frequency (8-50 Hz) activity during ketamine/xylazine versus nembutal anesthesia at surgical plane. Using FD we detected distinct inter-structure complexity pattern and uncovered for the first time that the polygraphically and behaviorally defined anesthetized state at surgical plane as equal during experiment in two anesthetic regimens, is not the same with respect to the degree of neuronal activity (degree of generalized neuronal inhibition achieved) at different brain levels. Using the correlation of certain brain structure EEG spectral characteristics with their corresponding FDs, and the surrogate data modeling, we determined what particular frequency band contributes to EEG complexities in ketamine/xylazine versus nembutal anesthesia. In this study we have shown that the quantitative relationship between higher frequency EEG amplitude and EEG complexity is the best-modeled by surrogate data as a 3rd order polynomial. On the base of our EEG amplitude/EEG complexity relationship model, and the evidenced spectral differences in ketamine versus nembutal anesthesia we have proved that higher amplitudes of sigma, beta, and gamma frequency in ketamine anesthesia yields to higher FDs.

  5. Generic pricing of FX, inflation and stock options under stochastic interest rates and stochastic volatility

    NARCIS (Netherlands)

    van Haastrecht, A.; Pelsser, A.

    2009-01-01

    We consider the pricing of FX, inflation and stock options under stochastic interest rates and stochastic volatility, for which we use a generic multi-currency framework. We allow for a general correlation structure between the drivers of the volatility, the inflation index, the domestic (nominal)

  6. Pre-anesthetic Anxiety Level in Children with Congenital Heart Disease: Comparison between Maternal Presence during Anesthetic Induction and Midazolam Premedication

    Directory of Open Access Journals (Sweden)

    Ratna F Soenarto

    2016-09-01

    Full Text Available General anesthesia was needed by children with congenital heart disease (CHD who underwent cardiaccatheterization procedure and surgery. Pre-anesthetic anxiety in children with CHD can cause significantproblems during induction of anesthesia which leads to negative postoperative outcomes. This studycompared the role of maternal presence during anesthesia induction with midazolam premedication onpre-anesthetic anxiety level in children with CHD. Dr. Cipto Mangunkusumo National Hospital on April toSeptember 2014. Forty-five CHD patients aged 2-5 years old who underwent cardiac invasive procedurewere divided into P group (received midazolam premedication and M group (had maternal presence duringanesthesia induction. Modified Yale Pre-anxiety Scale (MYPAS was used for measuring anxiety level ineach patient during preoperative visit, on the time patient entered the procedure room and during induction ofanesthesia. There was no significant difference of MYPAS scores between the two groups in all measurementtimes. The MYPAS score results were non-anxious (median score 23.4 and the highest was at induction ofanesthesia. Inter-rater agreement test between 2 observers was good (k>0.5. In conclusion, there was nosignificant difference between the effect of maternal presence during induction of anesthesia and midazolampremedication on pre-anesthetic anxiety level in children with CHD. Keywords: pre-anesthetic anxiety, congenital heart disease, maternal presence, midazolam.   Peran Kehadiran Ibu selama Induksi Anestesia dengan PremedikasiMidazolam terhadap Tingkat Kecemasan Pra-anestesia Anak denganPenyakit Jantung Bawan Abstrak Pembiusan umum diperlukan oleh pasien dengan penyakit jantung bawaan (PJB pada saat kateterisasiatau pembedahan jantung. Kecemasan pra-anestesia dapat menimbulkan masalah saat induksi anestesiayang berdampak negatif pascapembedahan. Penelitian ini bertujuan untuk membandingkan efek premedikasimidazolam dan kehadiran ibu selama

  7. Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

    Science.gov (United States)

    Ishida, Kazuyoshi; Berger, Miles; Nadler, Jacob; Warner, David S

    2014-01-01

    Anesthetics have been studied for nearly fifty years as potential neuroprotective compounds in both perioperative and resuscitation medicine. Although anesthetics present pharmacologic properties consistent with preservation of brain viability in the context of an ischemic insult, no anesthetic has been proven efficacious for neuroprotection in humans. After such effort, it could be concluded that anesthetics are simply not neuroprotective in humans. Moreover, pharmacologic neuroprotection with non-anesthetic drugs has also repeatedly failed to be demonstrated in human acute brain injury. Recent focus has been on rectification of promising preclinical neuroprotection data and subsequent failed clinical trials. This has led to consensus guidelines for the process of transferring purported therapeutics from bench to bedside. In this review we first examined the history of anesthetic neuroprotection research. Then, a systematic review was performed to identify major clinical trials of anesthetic neuroprotection. Both the preclinical neuroprotection portfolio cited to justify a clinical trial and the design and conduct of that clinical trial were evaluated using modern standards that include the Stroke Therapy Academic Industry Roundtable (STAIR) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. In publications intended to define anesthetic neuroprotection, we found overall poor quality of both preclinical efficacy analysis portfolios and clinical trial designs and conduct. Hence, using current translational research standards, it was not possible to conclude from existing data whether anesthetics ameliorate perioperative ischemic brain injury. Incorporation of advances in translational neuroprotection research conduct may provide a basis for more definitive and potentially successful clinical trials of anesthetics as neuroprotectants.

  8. Vasoconstriction Potency Induced by Aminoamide Local Anesthetics Correlates with Lipid Solubility

    Directory of Open Access Journals (Sweden)

    Hui-Jin Sung

    2012-01-01

    Full Text Available Aminoamide local anesthetics induce vasoconstriction in vivo and in vitro. The goals of this in vitro study were to investigate the potency of local anesthetic-induced vasoconstriction and to identify the physicochemical property (octanol/buffer partition coefficient, pKa, molecular weight, or potency of local anesthetics that determines their potency in inducing isolated rat aortic ring contraction. Cumulative concentration-response curves to local anesthetics (levobupivacaine, ropivacaine, lidocaine, and mepivacaine were obtained from isolated rat aorta. Regression analyses were performed to determine the relationship between the reported physicochemical properties of local anesthetics and the local anesthetic concentration that produced 50% (ED50 of the local anesthetic-induced maximum vasoconstriction. We determined the order of potency (ED50 of vasoconstriction among local anesthetics to be levobupivacaine > ropivacaine > lidocaine > mepivacaine. The relative importance of the independent variables that affect the vasoconstriction potency is octanol/buffer partition coefficient > potency > pKa > molecular weight. The ED50 in endothelium-denuded aorta negatively correlated with the octanol/buffer partition coefficient of local anesthetics (r2=0.9563; P<0.001. The potency of the vasoconstriction in the endothelium-denuded aorta induced by local anesthetics is determined primarily by lipid solubility and, in part, by other physicochemical properties including potency and pKa.

  9. Anesthetic management of hypertensive crisis in a three-year-old patient with undiagnosed severe renal artery stenosis: a case report.

    Science.gov (United States)

    Park, Sang-Hee; Lee, Yoon-Sook; Min, Too Jae; Kim, Woon Young; Kim, Jae Hwan; Park, Young Cheol

    2014-10-01

    Pediatric hypertensive crisis is a potentially life threatening medical emergency, usually secondary to an underlying disease. Hypertension commonly occurs during general anesthesia, and is usually promptly and appropriately treated by anesthesiologists. However in children with severe, unexplained, or refractory hypertension, it has the potential to cause morbidity and even mortality in susceptible patients. We report an anesthetic management of an unexpected hypertensive crisis that developed during general anesthesia in a three-year-old girl with undiagnosed severe left renal artery stenosis.

  10. Estimation of Dynamic Panel Data Models with Stochastic Volatility Using Particle Filters

    Directory of Open Access Journals (Sweden)

    Wen Xu

    2016-10-01

    Full Text Available Time-varying volatility is common in macroeconomic data and has been incorporated into macroeconomic models in recent work. Dynamic panel data models have become increasingly popular in macroeconomics to study common relationships across countries or regions. This paper estimates dynamic panel data models with stochastic volatility by maximizing an approximate likelihood obtained via Rao-Blackwellized particle filters. Monte Carlo studies reveal the good and stable performance of our particle filter-based estimator. When the volatility of volatility is high, or when regressors are absent but stochastic volatility exists, our approach can be better than the maximum likelihood estimator which neglects stochastic volatility and generalized method of moments (GMM estimators.

  11. Scleroderma and pulmonary hypertension complicating two pregnancies: use of neuraxial anesthesia, general anesthesia, epoprostenol and a multidisciplinary approach for cesarean delivery.

    Science.gov (United States)

    Moaveni, D; Cohn, J; Brodt, J; Hoctor, K; Ranasinghe, J

    2015-11-01

    Literature regarding the anesthetic care of patients with scleroderma during labor and delivery is limited to remote case reports. No recent publications provide information on the anesthetic management of patients with coexisting pulmonary hypertension. This report describes the anesthetic and multidisciplinary management of two pregnant patients with concomitant scleroderma and pulmonary hypertension undergoing cesarean delivery; one with neuraxial anesthesia and one with general anesthesia. Considerations for neuraxial and general anesthesia in patients with concurrent scleroderma and pulmonary hypertension are discussed.

  12. Recent Advances in Volatiles of Teas

    Directory of Open Access Journals (Sweden)

    Xin-Qiang Zheng

    2016-03-01

    Full Text Available Volatile compounds are important components of tea aroma, a key attribute of sensory quality. The present review examines the formation of aromatic volatiles of various kinds of teas and factors influencing the formation of tea volatiles, including tea cultivar, growing environment and agronomic practices, processing method and storage of tea. The determination of tea volatiles and the relationship of active-aroma volatiles with the sensory qualities of tea are also discussed in the present paper.

  13. Influence of Volatile Anesthesia on the Release of Glutamate and other Amino Acids in the Nucleus Accumbens in a Rat Model of Alcohol Withdrawal: A Pilot Study

    Science.gov (United States)

    Seidemann, Thomas; Spies, Claudia; Morgenstern, Rudolf; Wernecke, Klaus-Dieter; Netzhammer, Nicolai

    2017-01-01

    Background Alcohol withdrawal syndrome is a potentially life-threatening condition, which can occur when patients with alcohol use disorders undergo general anesthesia. Excitatory amino acids, such as glutamate, act as neurotransmitters and are known to play a key role in alcohol withdrawal syndrome. To understand this process better, we investigated the influence of isoflurane, sevoflurane, and desflurane anesthesia on the profile of excitatory and inhibitory amino acids in the nucleus accumbens (NAcc) of alcohol-withdrawn rats (AWR). Methods Eighty Wistar rats were randomized into two groups of 40, pair-fed with alcoholic or non-alcoholic nutrition. Nutrition was withdrawn and microdialysis was performed to measure the activity of amino acids in the NAcc. The onset time of the withdrawal syndrome was first determined in an experiment with 20 rats. Sixty rats then received isoflurane, sevoflurane, or desflurane anesthesia for three hours during the withdrawal period, followed by one hour of elimination. Amino acid concentrations were measured using chromatography and results were compared to baseline levels measured prior to induction of anesthesia. Results Glutamate release increased in the alcohol group at five hours after the last alcohol intake (p = 0.002). After 140 min, desflurane anesthesia led to a lower release of glutamate (p < 0.001) and aspartate (p = 0.0007) in AWR compared to controls. GABA release under and after desflurane anesthesia was also significantly lower in AWR than controls (p = 0.023). Over the course of isoflurane anesthesia, arginine release decreased in AWR compared to controls (p < 0.001), and aspartate release increased after induction relative to controls (p20min = 0.015 and p40min = 0.006). However, amino acid levels did not differ between the groups as a result of sevoflurane anesthesia. Conclusions Each of three volatile anesthetics we studied showed different effects on excitatory and inhibitory amino acid concentrations. Under

  14. Approximation methods of European option pricing in multiscale stochastic volatility model

    Science.gov (United States)

    Ni, Ying; Canhanga, Betuel; Malyarenko, Anatoliy; Silvestrov, Sergei

    2017-01-01

    In the classical Black-Scholes model for financial option pricing, the asset price follows a geometric Brownian motion with constant volatility. Empirical findings such as volatility smile/skew, fat-tailed asset return distributions have suggested that the constant volatility assumption might not be realistic. A general stochastic volatility model, e.g. Heston model, GARCH model and SABR volatility model, in which the variance/volatility itself follows typically a mean-reverting stochastic process, has shown to be superior in terms of capturing the empirical facts. However in order to capture more features of the volatility smile a two-factor, of double Heston type, stochastic volatility model is more useful as shown in Christoffersen, Heston and Jacobs [12]. We consider one modified form of such two-factor volatility models in which the volatility has multiscale mean-reversion rates. Our model contains two mean-reverting volatility processes with a fast and a slow reverting rate respectively. We consider the European option pricing problem under one type of the multiscale stochastic volatility model where the two volatility processes act as independent factors in the asset price process. The novelty in this paper is an approximating analytical solution using asymptotic expansion method which extends the authors earlier research in Canhanga et al. [5, 6]. In addition we propose a numerical approximating solution using Monte-Carlo simulation. For completeness and for comparison we also implement the semi-analytical solution by Chiarella and Ziveyi [11] using method of characteristics, Fourier and bivariate Laplace transforms.

  15. ANESTHETIC MANAGEMENT OF AN ANEMIC PARTURIENT WITH SEVERE KYPHOSCOLIOSIS AND BILATERAL POLIOMYELITIS FOR EMERGENCY CAESAREAN SECTION

    Directory of Open Access Journals (Sweden)

    Sujay

    2014-05-01

    Full Text Available Anesthesia for emergency caesarean section for a pregnant patient with severe dorsolumbar kyphoscoliosis and severe anemia is associated with potential risks for both mother and the fetus due to alterations in maternal physiology and the pathological changes associated with kyphoscoliosis. In an emergency situation, the anesthesiologist has to quickly choose the anesthetic technique depending on the cardiopulmonary status of the patient and feasibility. We present a case of a 20 year old parturient in labour with severe kyphoscoliosis and severe anemia who was posted for emergency caesarean section. In view of severe anemia, anticipated technical difficulties with central neuraxial blocks and emergency situation, she was administered general anesthesia (GA with uneventful recovery.

  16. Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery.

    Science.gov (United States)

    Ahiskalioglu, Elif Oral; Ahiskalioglu, Ali; Firinci, Binali; Dostbil, Aysenur; Aksoy, Mehmet

    2015-01-01

    Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  17. [Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery].

    Science.gov (United States)

    Ahiskalioglu, Elif Oral; Ahiskalioglu, Ali; Firinci, Binali; Dostbil, Aysenur; Aksoy, Mehmet

    2015-01-01

    Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. Anesthetic management for cesarean delivery in a Guillain-Barré syndrome patient -A case report-.

    Science.gov (United States)

    Kim, Hyunbin; Ryu, Junghee; Hwang, Jung-Won; Do, Sang-Hwan

    2013-03-01

    Guillain-Barré syndrome is an acute inflammatory demyelinating polyradiculopathy characterized by progressive motor weakness, areflexia, and ascending paralysis. Guillain-Barré syndrome is extremely rare in pregnant patients, and there are no established guidelines for delivery or safest anesthetic methods. We report a Cesarean delivery in the case of a 32-year old woman who was diagnosed with Guillain-Barré syndrome 18 weeks into gestation. Tracheostomy was performed due to progressive respiratory muscle weakness and respiratory failure, and ventilator support was required in the intensive care unit. The respiratory difficulty was exacerbated by the growth of the fetus, necessitating emergency Cesarean delivery. The delivery was successfully performed under general anesthesia, and the patient recovered without neurological sequelae.

  19. Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery

    Directory of Open Access Journals (Sweden)

    Elif Oral Ahiskalioglu

    2015-12-01

    Full Text Available ABSTRACT Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives.

  20. The influence of anesthetics, neurotransmitters and antibiotics on the relaxation processes in lipid membranes

    CERN Document Server

    Seeger, H M; Heimburg, T; Gudmundsson, Marie L.; Heimburg, Thomas; Seeger, Heiko M.

    2007-01-01

    In the proximity of melting transitions of artificial and biological membranes fluctuations in enthalpy, area, volume and concentration are enhanced. This results in domain formation, changes of the elastic constants, changes in permeability and slowing down of relaxation processes. In this study we used pressure perturbation calorimetry to investigate the relaxation time scale after a jump into the melting transition regime of artificial lipid membranes. This time corresponds to the characteristic rate of domain growth. The studies were performed on single-component large unilamellar and multilamellar vesicle systems with and without the addition of small molecules such as general anesthetics, neurotransmitters and antibiotics. These drugs interact with membranes and affect melting points and profiles. In all systems we found that heat capacity and relaxation times are related to each other in a simple manner. The maximum relaxation time depends on the cooperativity of the heat capacity profile and decreases...

  1. Ultrasound-guided greater auricular nerve block as sole anesthetic for ear surgery

    Directory of Open Access Journals (Sweden)

    Michael K. Ritchie

    2016-05-01

    Full Text Available A greater auricular nerve (GAN block was used as the sole anesthetic for facial surgery in an 80-year-old male patient with multiple comorbidities which would have made general anesthesia challenging. The GAN provides sensation to the ear, mastoid process, parotid gland, and angle of the mandible. In addition to anesthesia for operating room surgery, the GAN block can be used for outpatient or emergency department procedures without the need for a separate anesthesia team. Although this nerve block has been performed using landmark-based techniques, the ultrasoundguided version offers several potential advantages. These advantages include increased reliability of the nerve block, as well as prevention of inadvertent vascular puncture or blockade of the phrenic nerve, brachial plexus, or deep cervical plexus. The increasing access to ultrasound technology for medical care providers outside the operating room makes this ultrasound guided block an increasingly viable alternative.

  2. [Two cases of congenital airway obstruction managed with ex utero intrapartum treatment procedures: anesthetic implications].

    Science.gov (United States)

    Manrique, S; Blasco, J; Munar, F; Andreu, E; Mateo, M D; Suescun, M C; López Gil, M V

    2007-01-01

    An ex utero intrapartum treatment (EXIT) procedure provides sufficient time to gain control of the potentially obstructed fetal upper airway while uterine placental circulation is maintained during cesarean section. We report 2 cases in which fetal congenital upper airway obstruction was managed without complications during EXIT procedures. We also discuss general considerations concerning the obstetric patient and the performance of intramuscular fetal anesthesia. Before the hysterotomy, sevoflurane at 1.5 minimum alveolar concentration was administered to assure sufficient uterine relaxation during EXIT. The 2 parturients remained hemodynamically stable during the procedure and uterine and placental perfusion was adequate. Nasotracheal intubation was possible in 1 fetus after a cervical mass was dissected. In the other, a tracheostomy was created. After the umbilical cord was clamped, the concentration of sevoflurane anesthetic gas was reduced and oxytocin and methylergometrine were administered to induce adequate uterine contractions within a few minutes. Both neonates survived the EXIT procedure with no complications.

  3. Investigating Long-Range Dependence in American Treasury Bills Variations and Volatilities during Stable and Unstable Periods

    Science.gov (United States)

    Lahmiri, Salim

    2016-05-01

    Detrended fluctuation analysis (DFA) is used to examine long-range dependence in variations and volatilities of American treasury bills (TB) during periods of low and high movements in TB rates. Volatility series are estimated by generalized autoregressive conditional heteroskedasticity (GARCH) model under Gaussian, Student, and the generalized error distribution (GED) assumptions. The DFA-based Hurst exponents from 3-month, 6-month, and 1-year TB data indicates that in general the dynamics of the TB variations process is characterized by persistence during stable time period (before 2008 international financial crisis) and anti-persistence during unstable time period (post-2008 international financial crisis). For volatility series, it is found that; for stable period; 3-month volatility process is more likely random, 6-month volatility process is anti-persistent, and 1-year volatility process is persistent. For unstable period, estimation results show that the generating process is persistent for all maturities and for all distributional assumptions.

  4. COMPARISON OF COMMON CLINICALLY USED LOCAL ANESTHETICS ON ANIMAL MODELS

    Directory of Open Access Journals (Sweden)

    Anthireddy Srinivas

    2012-08-01

    Full Text Available The animal models used in this study were Plexus anesthesia in frogs, Infiltration anesthesia in guinea pigs, Surface anesthesia in rabbits. The drugs were diluted with normal saline. Lignocaine2%: xylocaine hydrochloride injection IP, Bupivacaine 0.5%: Bupivacaine hydrochloride injections IP were prepared. Plexus anesthesia: Frog was pithed and spinal cord was destroyed up to the 3 vertebra. The abdominal pouch was filled with local anesthetic solution. Reflex activity was tested by immersing both feet of the frog every two minutes for not longer than 10 seconds into N/10 Hydrochloric acid. The time was noted. Surface anesthesia: Albino rabbits of either sex weighing 2.5 – 3.0kg ware selected. The conjunctival sac of one eye was held open, thus formed a pouch. 0.5ml of solution of the anesthetic was applied into the conjunctival sac for 30 sec. Infiltration anesthesia: Preparation of guinea pig: Guinea pigs (either sex weighing 250-300grams were used. Lignocaine produced rapid onset of plexus anesthesia in Frogs in comparison to the bupivacaine at concentration of 0.1% & 0.2% which is statistically significant. Bupivacaine is more potent than the lignocaine as a surface anesthetic agent in the Rabbit, where as lignocaine could produce surface anesthesia at concentration of 0.5% or 0.1% or both. Both bupivacaine and lignocaine produced infiltration anesthesia on intradermal injection in guinea pigs but the duration of infiltration anesthesia produced by bupivacaine is more prolonged which is statistically significant in comparison to the lignocaine at all the three concentrations tested i.e. 0.05%, 0.1% & 0.2%.

  5. Anesthetic technique for inferior alveolar nerve block: a new approach

    Directory of Open Access Journals (Sweden)

    Dafna Geller Palti

    2011-02-01

    Full Text Available BACKGROUND: Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 13-29% of cases. OBJECTIVE: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. MATERIAL AND METHODS: A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side, and the second following the oclusal plane (left side, a line can be achieved whose projection coincides with the left mandibular foramen. RESULTS: The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. CONCLUSION: This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.

  6. Articaine - the best choice of local anesthetic in contemporary dentistry.

    Science.gov (United States)

    Nizharadze, N; Mamaladze, M; Chipashvili, N; Vadachkoria, D

    2011-01-01

    Local anesthesia forms the foundation of pain control techniques in clinical dentistry. Within the rich local anesthetic drugs available in dentistry for the prevention and management of pain 4% articaine solutions achieve highest level of anesthetic potency and lowest systemic toxicity in all clinical situations, prior to its superlative physicochemical characteristics and the pharmacological profile. These are - low lipid solubility, high plasma protein binding rate, fast metabolization, fast elimination half time; low blood level. Articaine inactivates in both ways: in the liver and the blood serum. It has good spreading through tissues. Thus, articaine seems to be the local anesthetic of first choice in tissues with suppurative inflammation, for adults, children (over 4), elderly, pregnant women, breastfeeding women, patients suffering from hepatic disorders and renal function impairment. In Articaine solutions (1: 200,000) epinephrine is in low concentration, thus in patients at high risk adverse responses are maximally decreased. In these patients articaine should be used with careful consideration of risk/benefit ratio. Articaine solutions must not be used in persons who are allergic or hypersensitive to sulphite, due to content of Sodium metabisulfite as vasoconstrictor's antioxidant in it. Incidence of serious adverse effects related to dental anesthesia with articaine is very low. Toxic reactions are usually due to an inadvertent intravascular injection or use of excessive dose. To avoid overdoses maximum recommendation dose (MRD) must not be exceeded and aspiration test always performed prior all LA injections. In these article we introduce new graphs providing a quick and effect way to determine maximum LA dose. If the overdose reactions develop, adherence to the basic step of emergency management with end to a successful outcome in virtually all cases.

  7. Spiral mining for lunar volatiles

    Science.gov (United States)

    Schmitt, H. H.; Kulcinski, G. L.; Sviatoslavsky, I. N.; Carrier, W. D., III

    Lunar spiral mining, extending outward from a periodically mobile central power and processing station represents an alternative for comparison with more traditional mining schemes. In this concept, a mining machine would separate regolith fines and extract the contained volatiles. Volatiles then would be pumped along the miner's support arm to the central station for refining and for export or storage. The basic architecture of the central processing station would be cylindrical. A central core area could house the power subsystem of hydrogen-oxygen engines or fuel cells. Habitat sections and other crew occupied areas could be arranged around the power generation core. The outer cylinder could include all volatile refining subsystems. Solar thermal power collectors and reflectors would be positioned on top of the central station. Long term exploitation of a volatile resource region would begin with establishment of a support base at the center of a long boundary of the region. The mining tract for each spiral mining system would extend orthogonal to this boundary. New spiral mining systems would be activated along parallel tracts as demand for lunar He-3 and other solar wind volatiles increased.

  8. Anesthetic management of a case with hereditary spherocytosis for splenectomy and open cholecystectomy

    Directory of Open Access Journals (Sweden)

    Sonal S Khatavkar

    2016-01-01

    Full Text Available Hereditary spherocytosis (HS is a familial hemolytic disorder with marked heterogeneity of clinical features ranging from asymptomatic condition to a fulminant hemolytic anemia. HS is characterized by the strong family history of anemia, jaundice, splenomegaly and cholelithiasis. Anesthetic Management of HS with liver dysfunction is very challenging since most of the anesthetic drugs are metabolized by the liver. Hereby, we report anesthetic management in a case of HS with splenomegaly and gall stones for elective splenectomy and cholecystectomy.

  9. RICE PRICE VOLATILITY IN EAST JAVA

    Directory of Open Access Journals (Sweden)

    Wati R.Y.E.

    2017-09-01

    Full Text Available The purpose of the research is analyzing the volatility and volatility spillover of monthly price of paddy at the level of farmers and consumers in 2010-2016. ARCH/GARCH used to analyze volatility and GARCH BEKK-model is used to analyze the volatility spillover. The results of the analysis show that price volatility at the farmer level is very high (extremely high volatility, price volatility at the consumer level is low (low volatility, and volatility spillover does not occur between the farmers and the consumers market. The need to guarantee an effective floor price as well as information disclosure related to the market commodity prices so that the pattern of prices transmission among interrelated markets can be symmetrical.

  10. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  11. In Vivo Quantitation of Local Anesthetic Suppression of Leukocyte Adherence

    Science.gov (United States)

    Giddon, D. B.; Lindhe, J.

    1972-01-01

    Using intravital microscopy, topically applied amide-type local anesthetics suppressed the adherence of leukocytes to the venular endothelium within surgical defects in the hamster cheek pouch. The response was reversible with physiologic saline and was localized to venules within the defect. Quantitation in terms of the percent of initially adhering leukocytes remaining in place on the venule wall at each minute following application of lidocaine and physiologic saline, respectively, revealed the suppression to be reliably related to the concentration, viz: 20.0 >10.0 >5.0 >0.0 mg ml of commercially available Xylocaine® (lidocaine) HCl. ImagesFig 1Fig 1 PMID:5049429

  12. The environmental impact of the Glostavent® anesthetic machine.

    Science.gov (United States)

    Eltringham, Roger J; Neighbour, Robert C

    2015-06-01

    Because anesthetic machines have become more complex and more expensive, they have become less suitable for use in the many isolated hospitals in the poorest countries in the world. In these situations, they are frequently unable to function at all because of interruptions in the supply of oxygen or electricity and the absence of skilled technicians for maintenance and servicing. Despite these disadvantages, these machines are still delivered in large numbers, thereby expending precious resources without any benefit to patients. The Glostavent was introduced primarily to enable an anesthetic service to be delivered in these difficult circumstances. It is smaller and less complex than standard anesthetic machines and much less expensive to produce. It combines a drawover anesthetic system with an oxygen concentrator and a gas-driven ventilator. It greatly reduces the need for the purchase and transport of cylinders of compressed gases, reduces the impact on the environment, and enables considerable savings. Cylinder oxygen is expensive to produce and difficult to transport over long distances on poor roads. Consequently, the supply may run out. However, when using the Glostavent, oxygen is normally produced at a fraction of the cost of cylinders by the oxygen concentrator, which is an integral part of the Glostavent. This enables great savings in the purchase and transport cost of oxygen cylinders. If the electricity fails and the oxygen concentrator ceases to function, oxygen from a reserve cylinder automatically provides the pressure to drive the ventilator and oxygen for the breathing circuit. Consequently, economy is achieved because the ventilator has been designed to minimize the amount of driving gas required to one-seventh of the patient's tidal volume. Additional economies are achieved by completely eliminating spillage of oxygen from the breathing system and by recycling the driving gas into the breathing system to increase the Fraction of Inspired Oxygen

  13. Cimetidine as pre-anesthetic agent for cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K; Holmskov, A

    1985-01-01

    In a prospective randomized study of 39 consecutive cesarean sections, 20 patients received cimetidine 400 mg intramuscularly as a pre-anesthetic, an 19 control patients were given NaCl. No perinatal effects on the infants were observed by cardiotocography before delivery, and K, Na, pH, PCO2, HCO......-3 and glucose values in capillary blood were nearly identical in the two groups 2 hours after birth, the difference being non-significant (p greater than 0.05). No respiratory effects or arrhythmias were observed. In another study comprising 8 elective cesarean sections in patients...

  14. Anesthetic management of a pediatric patient with neuroleptic malignant syndrome.

    Science.gov (United States)

    Bhalla, Tarun; Maxey, Douglas; Sawardekar, Amod; Tobias, Joseph D

    2012-04-01

    Neuroleptic malignant syndrome (NMS) is a rare disorder which is clinically similar to malignant hyperthermia (MH). It is characterized by hyperthermia, autonomic instability, muscle rigidity, coma, rhabdomyolysis, and acidosis. Without immediate and appropriate therapy, mortality may result. NMS is associated with administration of antipsychotic medications, anti-emetic medications, and changes in the dosage of anti-parkinsonian drugs. As several similarities exist between NMS and MH, differentiating between them can be a challenge for the clinician. We report anesthetic care during magnetic resonance imaging of the brain of a 14-year-old female with bipolar and schizoaffective disorders and the recent onset of NMS.

  15. Anesthetic management of a child with Hunter′s syndrome

    Directory of Open Access Journals (Sweden)

    Jasmeet Kaur

    2012-01-01

    Full Text Available Hunter′s syndrome is a member of a group of recessively inherited metabolic disorders termed mucopolysaccharidoses, caused by deficiency of lysosomal enzymes required for degradation of mucopolysaccharides or glycosaminoglycans, leading to accumulation of partially degraded glycosaminoglycans in various tissues. This leads to various anatomical abnormalities and systemic involvement, posing a challenge to an anesthetist. We present the anesthetic management of a 4-year old child with Hunter′s disease with anticipated difficult airway, who presented for adenotonsillectomy and repair of umbilical and inguinal hernia.

  16. Central bronchial carcinoid: Management of a case and anesthetic perspectives

    Science.gov (United States)

    Goswami, D; Kashyap, L; Batra, RK; Bhagat, C

    2016-01-01

    Obstructing lesions of the central airways present with a variety of symptoms and are often associated with pneumonia or asthma-like states. Anesthesia to these patients often presents challenges right from the preoperative stabilization of underlying lung condition, mask ventilation in the supine position to maintaining oxygenation and ventilation in the intraoperative and postoperative period. We present here a case of a young woman with a central bronchial tumor with significant airway obstruction with potential for major bleeding and subsequent anesthetic management without lung sacrificing measures and cardiopulmonary bypass assistance. PMID:26955320

  17. Central bronchial carcinoid: Management of a case and anesthetic perspectives

    Directory of Open Access Journals (Sweden)

    D Goswami

    2016-01-01

    Full Text Available Obstructing lesions of the central airways present with a variety of symptoms and are often associated with pneumonia or asthma-like states. Anesthesia to these patients often presents challenges right from the preoperative stabilization of underlying lung condition, mask ventilation in the supine position to maintaining oxygenation and ventilation in the intraoperative and postoperative period. We present here a case of a young woman with a central bronchial tumor with significant airway obstruction with potential for major bleeding and subsequent anesthetic management without lung sacrificing measures and cardiopulmonary bypass assistance.

  18. [Anesthetic management of a patient with suspected pseudothrombocytopenia].

    Science.gov (United States)

    Hashimoto, Manabu; Kouchi, Akira; Inaba, Shin; Motomura, Yuji; Takahashi, Minoru

    2003-10-01

    A 74-year-old male was operated for sigmoid colon cancer. Because of an agglutination of the patient's platelet, it was difficult to measure his platelet count under ethylene diamine tetra acetate (EDTA), heparin or citrate as anticoagulants with an automated cell counter. Even though there was a strong possibility of pseudothrombocytopenia, anesthetic management for the patient was safely conducted. His condition was stable throughout the perioperative course and no bleeding tendency was observed. Nitrous oxide, oxygen, sevoflurane, propofol and pancuronium were useful in this case.

  19. Precise determination of refractometric parameters for anesthetic agent vapors.

    Science.gov (United States)

    Allison, J M; Birch, K P; Crowder, J G

    1994-05-01

    The absolute refractive indices of the anesthetic agent vapors isoflurane, sevoflurane, enflurane, halothane, and desflurane are determined to a typical uncertainty of 1 part in 10(7) over the respective temperature and pressure ranges of 15-40 °C and 5-45% of their saturated vapor pressures at wavelengths of 632.99, 594.10, and 543.52 nm. The specific refraction, second virial coefficients, and dispersion constants are also derived for each agent, from which an equation for the calculation of agent refractivity is established that is in agreement with the measured data to within 2 × 10(-8).

  20. Loss of anatomical landmarks with eutectic mixture of local anesthetic cream for neonatal male circumcision.

    Science.gov (United States)

    Plank, Rebeca M; Kubiak, David W; Abdullahi, Rasak Bamidele; Ndubuka, Nnamdi; Nkgau, Maggie M; Dapaah-Siakwan, Fredrick; Powis, Kathleen M; Lockman, Shahin

    2013-02-01

    We report two cases of newborns who developed marked local edema after application of a eutectic mixture of local anesthetic (EMLA) topical anesthetic cream for neonatal male circumcision (NMC). Although local edema and erythema are known potential side effects of EMLA cream, a common anesthetic used for NMC, the loss of landmarks precluding safe NMC has not previously been reported, and is described here. Although we cannot recommend an alternate local anesthetic for neonates with this reaction to EMLA, based on a review of the published data we think that serious systemic adverse events related to EMLA are extremely rare.

  1. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  2. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  3. Rhenium volatilization in waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: pavel.hrma@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)

    2015-09-15

    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  4. Tolerability of NGX-4010, a capsaicin 8% patch, in conjunction with three topical anesthetic formulations for the treatment of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Webster LR

    2012-01-01

    Full Text Available Lynn R Webster1, John F Peppin2, Frederick T Murphy3,4, Jeffrey K Tobias5, Geertrui F Vanhove51Lifetree Clinical Research and Pain Clinic, Lifetree Medical Inc, Salt Lake City, UT, USA; 2Clinical Research Division, The Pain Treatment Center of the Bluegrass, Lexington, KY, USA; 3Altoona Center for Clinical Research, Duncansville, PA, USA; 4University of Pennsylvania, School of Medicine, Philadelphia, PA, USA; 5NeurogesX Inc, San Mateo, CA, USABackground: The objective of this study was to assess the safety, tolerability, and preliminary efficacy of NGX-4010, a capsaicin 8% patch, following pretreatment with three different topical anesthetics in patients with peripheral neuropathic pain.Methods: This open-label, multicenter study enrolled 117 patients with post-herpetic neuralgia, HIV-associated distal sensory polyneuropathy, or painful diabetic neuropathy. Patients received pretreatment with one of three lidocaine 4%-based topical anesthetics (L.M.X.4® [Ferndale Laboratories Inc, Ferndale, MI], Topicaine® Gel [Estela Basso, Jupiter, FL], or Betacaine Enhanced Gel 4 [Tiberius Inc, Tampa, FL] for 60 minutes followed by a single 60- or 90-minute NGX-4010 application, and were followed for 12 weeks. Tolerability and safety measures included “pain now” Numeric Pain Rating Scale (NPRS scores, dermal assessments, medication use for treatment-related pain, adverse events (AEs, clinical laboratory parameters, physical examinations, and vital signs. The primary efficacy variable was the percentage change in mean NPRS scores for “average pain for the past 24 hours” from baseline to weeks 2 through 12.Results: Treatment with NGX-4010 following pretreatment with any of the three topical anesthetics was generally safe and well tolerated. Nearly all patients completed ≥90% of the planned NGX-4010 application duration. The most common treatment-related AEs, application-site burning and application-site pain, were transient, mostly mild or moderate

  5. Leverage and Feedback Effects on Multifactor Wishart Stochastic Volatility for Option Pricing

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThe paper proposes a general asymmetric multifactor Wishart stochastic volatility (AMWSV) diffusion process which accommodates leverage, feedback effects and multifactor for the covariance process. The paper gives the closed-form solution for the conditional and unconditional Laplace

  6. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  7. Modeling and Forecasting Volatility of the Malaysian Stock Markets

    Directory of Open Access Journals (Sweden)

    Ahmed Shamiri

    2009-01-01

    Full Text Available Problem statement: One of the main purposes of modeling variance is forecasting, which is crucial in many areas of finance. Despite the burgeoning interest in and evaluation of volatility forecasts, a clear consensus on witch volatility model/or distribution specification to use has not yet been reached. Therefore, the out of-sample forecasting ability should be a natural model selection criterion for volatility models. Approach: In this study, we used high-frequency to facilitate meaningful comparison of volatility forecast models. We compared the performance of symmetric GARCH, asymmetric EGARCH and non leaner asymmetric NAGARCH models with six error distributions (normal, skew normal, student-t, skew student-t, generalized error distribution and normal inverse Gaussian. Results: The results suggested that allowing for a heavy-tailed error distribution leads to significant improvements in variance forecasts compared to using normal distribution. It was also found that allowing for skewness in the higher moments of the distribution did not further improve forecasts. Conclusion: Successful volatility model forecast depended much more heavily on the choice of error distribution than the choice of GARCH models.

  8. Volatile Concentrations and H-Isotope Composition of Unequilibrated Eucrites

    Science.gov (United States)

    Sarafian, Adam R.; Nielsen, Sune G.; Marschall, Horst R.; Gaetani, Glenn A.; Hauri, Erik H.; Righter, Kevin; Berger, Eve L.

    2017-01-01

    Eucrites are among the oldest and best studied asteroidal basalts (1). They represent magmatism that occurred on their parent asteroid, likely 4-Vesta, starting at 4563 Ma and continuing for approx. 30 Myr. Two hypotheses are debated for the genesis of eucrites, a magma ocean model (2), and a mantle partial melting model. In general, volatiles (H, C, F, Cl) have been ignored for eucrites and 4-Vesta, but solubility of wt% levels of H2O are possible at Vestan interior PT conditions. Targeted measurements on samples could aid our understanding considerably. Recent studies have found evidence of volatile elements in eucrites, but quantifying the abundance of volatiles remains problematic (6). Volatile elements have a disproportionately large effect on melt properties and phase stability, relative to their low abundance. The source of volatile elements can be elucidated by examining the hydrogen isotope ratio (D/H), as different H reservoirs have drastically different H isotope compositions. Recent studies of apatite in eucrites have shown that the D/H of 4-Vesta matches that of Earth and carbonaceous chondrites, however, the D/H of apatites may not represent the D/H of a primitive 4-Vesta melt due to the possibility of degassing prior to the crystallization of apatite. Therefore, the D/H of early crystallizing phases must be measured to determine if the D/H of 4-Vesta is equal to that of the Earth and carbonaceous chondrites.

  9. Achieving pulpal anesthesia with a topical anesthetic paste

    Directory of Open Access Journals (Sweden)

    Bradley Carn

    2015-01-01

    Full Text Available Aim: The efficacy of a topically applied formulation of tetracaine base (6% was investigated against benzocaine in achieving pulpal anesthesia in a randomized, placebo-controlled, double-blind study. Materials and Methods: Subjects′ baseline pulpal responses to an electric pulp tester were measured, followed by a 10 min application of either tetracaine anesthetic paste (TAP, benzocaine (20%, or placebo. Treatments were removed and pulp testing was performed at 10 min, 15 min, and 20 min postapplication. Results: TAP produced significant pulpal anesthesia at 184% ± 7.2% above baseline versus 14% ± 1.7% above baseline for benzocaine at 15 min (P < 0.03. Differences between treatments were tested with the Wilcoxon test and the Steel-Dwass test, which is the nonparametric version of the all-pairs Tukey′s honestly significant difference test. Conclusion: Achieving profound anesthesia with a topical anesthetic paste could lead to injection less procedure, improved postsurgical incisional pain management, and ameliorate pain associated with a variety of lesions.

  10. Use of eutectic mixture of local anesthetics in children.

    Science.gov (United States)

    Dutta, S

    1999-01-01

    The Eutectic Mixture of Local Anesthetics (EMLA) is a topical application, which has proved to be a useful medication for providing pain relief among children. It is an emulsion containing a 1:1 mixture of lidocaine and prilocaine. The high concentration of the uncharged anesthetic base in the microdroplets of the emulsion ensure effective skin penetration. In the pediatric population EMLA has been shown to be efficacious when it is used prior to venipuncture, cannulation, lumbar puncture, laser treatment of port wine stains, curettage of molluscum contagiosum or vaccination. For several of these indications, the efficacy has been documented by double blind controlled trials, that have used objective and quasi-objective scales for assessing pain relief. The dose of EMLA is between 0.5 to 1 gram, and the cream should be applied half to one hour prior to the procedure. Local side effects are very mild, and the only systemic side effect of importance is the risk of methemoglobinemia in young infants. The literature has conflicting reports about the safety of EMLA in neonates.

  11. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

    Directory of Open Access Journals (Sweden)

    Prontera A

    2017-03-01

    Full Text Available Andrea Prontera,1 Stefano Baroni,2 Andrea Marudi,2 Franco Valzania,3 Alberto Feletti,1 Francesca Benuzzi,4 Elisabetta Bertellini,2 Giacomo Pavesi1 1Department of Neurosurgery, Nuovo Ospedale Civile SAgostino-Estense, 2Department of Anesthesiology, Nuovo Ospedale Civile SAgostino-Estense, 3Department of Neurology, Nuovo Ospedale Civile S Agostino-Estense, 4Department of Neuroscience, University of Modena and Reggio Emilia, Modena, Italy Introduction: Awake craniotomy allows continuous monitoring of patients’ neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic–sedative medication is increasing.Methods: Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management.Results: The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure.Conclusion: In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used. Keywords: dexmedetomidine, awake surgery, anesthesia

  12. Lung Physiology and Obesity: Anesthetic Implications for Thoracic Procedures

    Directory of Open Access Journals (Sweden)

    Alessia Pedoto

    2012-01-01

    Full Text Available Obesity is a worldwide health problem affecting 34% of the American population. As a result, more patients requiring anesthesia for thoracic surgery will be overweight or obese. Changes in static and dynamic respiratory mechanics, upper airway anatomy, as well as multiple preoperative comorbidities and altered drug metabolism, characterize obese patients and affect the anesthetic plan at multiple levels. During the preoperative evaluation, patients should be assessed to identify who is at risk for difficult ventilation and intubation, and postoperative complications. The analgesia plan should be executed starting in the preoperative area, to increase the success of extubation at the end of the case and prevent reintubation. Intraoperative ventilatory settings should be customized to the changes in respiratory mechanics for the specific patient and procedure, to minimize the risk of lung damage. Several non invasive ventilatory modalities are available to increase the success rate of extubation at the end of the case and to prevent reintubation. The goal of this review is to evaluate the physiological and anatomical changes associated with obesity and how they affect the multiple components of the anesthetic management for thoracic procedures.

  13. Electrocardiographic effects of toluene in the anesthetized rat.

    Science.gov (United States)

    Vidrio, H; Magos, G A; Lorenzana-Jimenez, M

    1986-01-01

    The influence of inhalation of near lethal quantities of toluene on some ECG parameters, as well as the possible cardiac sensitizing effect of the solvent, were determined in chloralose-anesthetized rats. These actions were compared with those of its close analogue benzene. Both solvents produced tachycardia; toluene increased the duration of QRS and specially PR, while benzene decreased P wave duration. No other systematic changes in ECG morphology or evidence of arrhythmia were observed. Toluene appeared to decrease the number of ectopic beats induced by epinephrine, in contrast to benzene, which increased it markedly. These results suggest that toluene administered by inhalation up to near lethal doses is devoid of untoward ECG effect in the chloralose-anesthetized rat, its only action being a decrease in intraventricular and particularly AV conduction. It does not share the myocardial sensitizing properties of benzene and in fact appears to elicit some protection from the arrhythmogenic effects of epinephrine, although no definite conclusions as to this action can be derived due to limitations in the experimental model used.

  14. Effect of anesthetics on the radiosensitivity of a murine tumor

    Energy Technology Data Exchange (ETDEWEB)

    Sheldon, P.W.; Chu, A.M.

    1979-09-01

    The effect of four anesthetics on the single dose of x rays required to locally control 50% of implanted MT tumors was investigated. Compared with unanesthetized animals, no change in radiosensitivity was observed if mice were irradiated under either tribromoethanol or fentanyl-fluanisone-diazepam anesthesia. However, a small but significant degree of radioprotection was observed under chloral hydrate or pentobarbital anesthesia. Hypothermia or increased hypoxia are considered unlikely mechanisms for the protection, a direct chemical action being most probable. The preferred method for immobilizing the mice in order to locally irradiate the tumors was by simple physical restraint (with care taken to minimize physiological stress). However, if anesthesia was a necessity, the present work suggests that for the MT tumor at least the nonprotecting tribromoethanol and fentanyl-fluanisone-diazepam are preferable to the protecting chloral hydrate and pentobarbital. Tribromoethanol is preferable to fetanyl-fluanisone-diazepam in that it produces a smaller drop in temperature. However, it is only a short-acting anesthetic, and prolongation of the state of anesthesia by repeated doses simply prolongs the temperature decline so that there may be no real benefit over fentanyl-fluanisone-diazepam.

  15. [Anesthetic consideration in patients undergoing catheter ablation for atrial fibrillation].

    Science.gov (United States)

    Oda, Toshiyuki; Takahama, Yutaka

    2012-11-01

    This chapter describes anesthetic consideration in patients undergoing catheter ablation for atrial fibrillation (AF) based on electrophysiologic or pharmacological aspects. In the 2011 guidelines of the Japanese Circulation Society for non-pharmacotherapy of cardiac arrhythmias, catheter ablation is recommended as Class I therapeutic modality for the patients with drug-refractory paroxysmal AF. Catheter ablation of AF is an invasive and long-lasting procedure necessitating sedation during treatment. However, in the most of the patients, sedation or anesthesia is possibly performed by cardiologists using propofol, midazolam or dexmedetomidine. Deep sedation accompanies a high risk of ventilatory or circulatory derangement. Furthermore, life-threatening complications, such as cerebral infarction or cardiac tamponade, can occur during ablation. Patients with AF are increasing in number as a trend in the aging society, resulting in an increase in catheter ablation in high risk patients. To accomplish safe anesthetic management of the patients for catheter ablations, anesthesiologists are required to have fundamental knowledge and skill in the performance of the catheter ablation.

  16. Volatile loss from accreting icy protoplanets

    Science.gov (United States)

    Stevenson, D. J.

    1993-03-01

    A large self-gravitating body does not easily lose significant mass because the escape velocity is much larger than the sound speed of atmosphere-forming species under ambient thermal conditions. The most significant exceptions to this are giant impacts or impact jetting by fast-moving projectiles. A very small object (e.g. a comet) also does not easily lose significant volatile mass upon formation because the energy release associated with its accretion is so small. (It can however lose a great deal of mass if it is subsequently moved closer to the Sun.) I argue that there is an intermediate mass range (corresponding to bodies with radii of approximately 300-800 km) for which the ambient steady-state mass loss is a maximum. By ambient, I mean those conditions pertaining to the formation region of the body. By steady state, I mean to exclude infrequent traumas (giant impacts). The existence of a preferred intermediate mass arises through the competition of growing gravitational containment and growing energy release by accretion; it corresponds typically to GM/(Rcs2) approximately equals 2 to 4, where M is the protoplanet mass of radius R, and cs is the sound speed. Several factors determine the amount of volatile loss is this vulnerable zone during accretion but in general the loss is a substantial fraction of the volatiles, sometimes approaching 100 percent. The principal implication is that bodies larger than a few hundred kilometers in radius will not have a 'primitive' (i.e. cometary) composition. This is relevant for understanding Triton, Pluto, Charon, and perhaps Chiron.

  17. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  18. Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mashimo, T.; Abe, K.; Yoshiya, I.

    1986-04-01

    The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

  19. Effects of local anesthetics on Na+ channels containing the equine hyperkalemic periodic paralysis mutation.

    Science.gov (United States)

    Sah, R L; Tsushima, R G; Backx, P H

    1998-08-01

    We examined the ability of local anesthetics to correct altered inactivation properties of rat skeletal muscle Na+ channels containing the equine hyperkalemic periodic paralysis (eqHPP) mutation when expressed in Xenopus oocytes. Increased time constants of current decay in eqHPP channels compared with wild-type channels were restored by 1 mM benzocaine but were not altered by lidocaine or mexiletine. Inactivation curves, which were determined by measuring the dependence of the relative peak current amplitude after depolarization to -10 mV on conditioning prepulse voltages, could be shifted in eqHPP channels back toward that observed for wild-type (WT) channels using selected concentrations of benzocaine, lidocaine, and mexiletine. Recovery from inactivation at -80 mV (50-ms conditioning pulse) in eqHPP channels followed a monoexponential time course and was markedly accelerated compared with wild-type channels (tauWT = 10.8 +/- 0.9 ms; taueqHPP = 2.9 +/- 0.4 ms). Benzocaine slowed the time course of recovery (taueqHPP,ben = 9.6 +/- 0.4 ms at 1 mM) in a concentration-dependent manner. In contrast, the recovery from inactivation with lidocaine and mexiletine had a fast component (taufast,lid = 3.2 +/- 0.2 ms; taufast,mex = 3.1 +/- 0.2 ms), which was identical to the recovery in eqHPP channels without drug, and a slow component (tauslow,lid = 1,688 +/- 180 ms; tauslow,mex = 2,323 +/- 328 ms). The time constant of the slow component of the recovery from inactivation was independent of the drug concentration, whereas the fraction of current recovering slowly depended on drug concentrations and conditioning pulse durations. Our results show that local anesthetics are generally incapable of fully restoring normal WT behavior in inactivation-deficient eqHPP channels.

  20. Plethysmographic variability index (PVI) accuracy in predicting fluid responsiveness in anesthetized children.

    Science.gov (United States)

    Julien, Florence; Hilly, Julie; Sallah, Tarik B; Skhiri, Alia; Michelet, Daphné; Brasher, Christopher; Varin, Laurent; Nivoche, Yves; Dahmani, Souhayl

    2013-06-01

    Plethysmographic Variability Index (PVI) has been shown to accurately predict responsiveness to fluid loads in adults. The goal of this study was to evaluate PVI accuracy when predicting fluid responsiveness during noncardiac surgery in children. Children aged 2-10 years scheduled for noncardiac surgery under general anesthesia were included. PVI was assessed concomitantly with stroke volume index (SVI). A response to fluid load was defined by an SVI increase of more than 15%. A 10 ml·kg(-1) normal saline intravenous fluid challenge was administered before surgical incision and after anesthetic induction. After incision, fluid challenges were administered when SVI values decreased by more than 15% or where judged necessary by the anesthesiologist. Statistical analyses include receiving operator characteristics (ROC) analysis and the determination of gray zone method with an error tolerance of 10%. Fifty-four patients were included, 97 fluid challenges administered and 45 responses recorded. Area under the curve of ROC curves was 0.85 [0.77-0.93] and 0.8 [0.7-0.89] for baseline PVI and SVI values, respectively. Corresponding gray zone limits were [10-17%] and [22-31 ml·m(-2)], respectively. PVI values exhibited different gray zone limits for pre-incision and postincision fluid challenges, whereas SVI values were comparable. PVI value percentages in the gray zone were 34% overall and 44% for challenges performed after surgical incision. This study found both PVI and prechallenge SVI to be accurate when used to predict fluid load response during anesthetized noncardiac surgery in children. However, a third of recorded PVI values were inconclusive. © 2013 Blackwell Publishing Ltd.

  1. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  2. A Fractionally Integrated Wishart Stochastic Volatility Model

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThere has recently been growing interest in modeling and estimating alternative continuous time multivariate stochastic volatility models. We propose a continuous time fractionally integrated Wishart stochastic volatility (FIWSV) process. We derive the conditional Laplace transform of

  3. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...

  4. Positive Allosteric Modulation of Kv Channels by Sevoflurane: Insights into the Structural Basis of Inhaled Anesthetic Action.

    Directory of Open Access Journals (Sweden)

    Qiansheng Liang

    Full Text Available Inhalational general anesthesia results from the poorly understood interactions of haloethers with multiple protein targets, which prominently includes ion channels in the nervous system. Previously, we reported that the commonly used inhaled anesthetic sevoflurane potentiates the activity of voltage-gated K+ (Kv channels, specifically, several mammalian Kv1 channels and the Drosophila K-Shaw2 channel. Also, previous work suggested that the S4-S5 linker of K-Shaw2 plays a role in the inhibition of this Kv channel by n-alcohols and inhaled anesthetics. Here, we hypothesized that the S4-S5 linker is also a determinant of the potentiation of Kv1.2 and K-Shaw2 by sevoflurane. Following functional expression of these Kv channels in Xenopus oocytes, we found that converse mutations in Kv1.2 (G329T and K-Shaw2 (T330G dramatically enhance and inhibit the potentiation of the corresponding conductances by sevoflurane, respectively. Additionally, Kv1.2-G329T impairs voltage-dependent gating, which suggests that Kv1.2 modulation by sevoflurane is tied to gating in a state-dependent manner. Toward creating a minimal Kv1.2 structural model displaying the putative sevoflurane binding sites, we also found that the positive modulations of Kv1.2 and Kv1.2-G329T by sevoflurane and other general anesthetics are T1-independent. In contrast, the positive sevoflurane modulation of K-Shaw2 is T1-dependent. In silico docking and molecular dynamics-based free-energy calculations suggest that sevoflurane occupies distinct sites near the S4-S5 linker, the pore domain and around the external selectivity filter. We conclude that the positive allosteric modulation of the Kv channels by sevoflurane involves separable processes and multiple sites within regions intimately involved in channel gating.

  5. TMVOC, simulator for multiple volatile organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten; Battistelli, Alfredo

    2003-03-25

    TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem.

  6. Business Cycles, Financial Crises, and Stock Volatility

    OpenAIRE

    G. William Schwert

    1989-01-01

    This paper shows that stock volatility increases during recessions and financial crises from 1834-1987. The evidence reinforces the notion that stock prices are an important business cycle indicator. Using two different statistical models for stock volatility, I show that volatility increases after major financial crises. Moreover. stock volatility decreases and stock prices rise before the Fed increases margin requirements. Thus, there is little reason to believe that public policies can con...

  7. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...... (stock) volatilities are mainly influenced by bond (stock) effects. Global, regional, and local volatility effects are all important. The introduction of the euro is associated with a structural break....

  8. Exponential Smoothing, Long Memory and Volatility Prediction

    DEFF Research Database (Denmark)

    Proietti, Tommaso

    Extracting and forecasting the volatility of financial markets is an important empirical problem. The paper provides a time series characterization of the volatility components arising when the volatility process is fractionally integrated, and proposes a new predictor that can be seen as extensi...... methods for forecasting realized volatility, and that the estimated model confidence sets include the newly proposed fractional lag predictor in all occurrences....

  9. Possible Sources of Polar Volatiles

    Science.gov (United States)

    Schultz, P. H.

    2011-12-01

    Extensive analyses of returned Apollo samples demonstrated that the Moon is extremely volatile poor. While this conclusion remains true, various measurements since the late 90's implicated the presence of water: e.g., enhanced reflection of circularly polarized radar signals and suppression of epithermal neutrons near the poles. More recently, traces of H2O have been discovered inside volcanic glass, along with more significant amounts residing in hydrous minerals (apatite) returned from both highland and mare landing sites. Three recent lunar missions (DIXI, M3, Cassini) identified hydrous phases on/near the lunar surface, whereas the LCROSS probe detected significant quantities of volatiles (OH, H2O and other volatiles) excavated by the Centaur impact. These new mission results and sample studies, however, now allow testing different hypotheses for the generation, trapping, and replenishment of these volatiles. Solar-proton implantation must contribute to the hydrous phases in the lunar regolith in order to account for the observed time-varying abundances and occurrence near the lunar equator. This also cannot be the entire story. The relatively low speed LCROSS-Centaur impact (2.5km/s) could not vaporize such hydrous minerals, yet emissions lines of OH (from the thermal disassociation of H2O), along with other compounds (CO2, NH2) were detected within the first second, before ejecta could reach sunlight. Telescopic observations by Potter and Morgan (1985) discovered a tenuous lunar atmosphere of Na, but the LCROSS UV/Vis spectrometer did not detect the Na-D line until after the ejecta reached sunlight (along with a line pair attributed to Ag). With time, other volatile species emerged (OH, CO). The LAMP instrument on the Lunar Reconnaissance Orbiter had a different viewpoint from the side (rather than from above) and detected many other atomic species release by the LCROSS-Centaur impact. Consequently, it appears that there is a stratigraphy for trapped species

  10. Lipídeos nas intoxicações por anestésicos locais Lipids in local anesthetic toxicity

    Directory of Open Access Journals (Sweden)

    Artur Udelsmann

    2012-09-01

    Full Text Available INTRODUÇÃO: Com o advento dos anestésicos locais de longa duração, a anestesia locorregional ganhou grande impulso sendo cada vez mais utilizada. Novas técnicas de bloqueios foram descritas e a técnica é frequentemente associada à anestesia geral com o objetivo de proporcionar analgesia pós-operatória. A contra-partida é a necessidade da utilização de grandes doses com risco de acidentes por injeção intravascular inadvertida; trata-se de complicação grave sem tratamento específico até há alguns anos. Em 1998 foi proposta a utilização de emulsões lipídicas em animais e a partir de 2006 vários trabalhos demonstraram o interesse dessas soluções nos casos de intoxicações por anestésicos locais com diminuição da morbi-mortalidade. O objetivo desta revisão foi fazer um levantamento da metodologia, revisando os mecanismos, interesses, limites e as condutas preconizadas atualmente. MÉTODO: Foram revistas algumas referências históricas sobre anestésicos locais, artigos publicados nos últimos 30 anos em revistas indexadas no Medline e em dois livros-texto. Foram selecionados os artigos que tratavam da intoxicação por anestésicos locais, da terapia com emulsões lipídicas, os de revisão sobre o assunto e as condutas adotadas em diversos serviços e países, sendo realizada uma síntese. CONCLUSÕES: A eficiência e interesse da terapia com emulsões lipídicas nas intoxicações por anestésicos locais não é mais a demonstrar; várias sociedades da especialidade já publicaram suas diretrizes e aconselham que se disponha desses produtos nos locais onde se pratica a anestesia locorregional.INTRODUCTION: With the advent of long-lasting local anesthetics, local and regional anesthesia gained considerable impetus and the use of these techniques has become increasingly widespread. New block techniques have been described and regional anesthesia is frequently associated with general anesthesia to provide

  11. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average r...

  12. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures o

  13. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures

  14. Ammonia volatilization from intensively managed dairy pastures.

    NARCIS (Netherlands)

    Bussink, D.W.

    1996-01-01

    The objectives of this thesis are (i) to quantify NH 3 volatilization from grassland, (ii) to gain understanding of the NH3 volatilization processes on grassland and (iii) to study measures how to reduce NH 3 volatilization from gra

  15. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average r...

  16. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...

  17. Bupivacaine Lozenge Compared with Lidocaine Spray as Topical Pharyngeal Anesthetic before Unsedated Upper Gastrointestinal Endoscopy

    DEFF Research Database (Denmark)

    Salale, Nesrin; Treldal, Charlotte; Mogensen, Stine;

    2014-01-01

    Unsedated upper gastrointestinal endoscopy (UGE) can induce patient discomfort, mainly due to a strong gag reflex. The aim was to assess the effect of a bupivacaine lozenge as topical pharyngeal anesthetic compared with standard treatment with a lidocaine spray before UGE. Ninety-nine adult...... with a lidocaine spray proved to be a superior option as topical pharyngeal anesthetic before an UGE....

  18. [Anesthetic machine leakage from vaporizer by external force derived from keyboard of electronic medical records].

    Science.gov (United States)

    Ikegami, Hiromi; Goto, Ryokichi; Sakamoto, Syotarou; Kohama, Hanako

    2012-11-01

    We experienced the leakage from the vaporizer of the anesthetic machine despite the normalities on performing the initial leak test. The vaporizer of the anesthetic machine was compressed by computer keyboard of EMR which caused a leak from vaporizer. After computer keyboard and the vaporizer were set at normal position, the leak stopped.

  19. A Comparison of Hamster Anesthetics and Their Effect on Mosquito Blood Feeding

    Science.gov (United States)

    Hamsters or mice are often anesthetized when they are used as the hosts for insect feeding experiments. An experiment was done to determine if there was a difference in mosquito blood feeding success when fed on hamsters anesthetized using two commonly used protocols. The number of blood-fed females...

  20. Anesthetic success of 1.8ml lidocaine 2% for mandibular tooth extraction. A pilot study

    Directory of Open Access Journals (Sweden)

    Pedro Aravena

    2013-04-01

    Full Text Available Aim: To determine the anesthetic effect of a 1.8ml cartridge of anesthetic lidocaine 2% with epinephrine 1:100,000 in inferior alveolar nerve block (NAI for the extraction in mandibular teeth. Material and methods: A pilot study with analitic design. Participating patients of Dental Emergency Service volunteers from Valdivia-Chile for mandibular teeth extractions attending between May and July of 2010. The anesthetic technique was performed by a dentist using only one cartridge of anesthetic to the NAI. After 15 minutes, the effect was considered effective when anesthetic not require reinforcement with additional anesthesia during extraction of teeth. We analyzed the relationship between success anesthetic effect with sex, age, diagnosis of tooth and type and level of pain observed (chi-square and logistic regression, p<0.05. Results: 62 patients were selected, of which only 47(75.8% was achieved anesthetic success. There was no statistical association with sex, age, type or dental diagnosis and perceived pain. Conclusion: Using a 1.8ml cartridge of anesthesia was effective in three of four patients treated by extraction of mandibular teeth. It suggests further research in relation to the clinical effectiveness of other anesthetics with the same dose in NAI.

  1. [Anesthetic management of a patient with stiff-person syndrome undergoing thymectomy].

    Science.gov (United States)

    Tadokoro, Takahiro; Yamashita, Soichiro; Ishigaki, Maiko; Takahashi, Shinji; Tanaka, Makoto

    2012-02-01

    Stiff-person syndrome is an uncommon disease characterized by muscular rigidity and painful spasms in the axial and limb muscles. We report a 58-year-old woman with stiff-person syndrome undergoing thymectomy under general anesthesia. Before surgery, her medications were 25 mg of diazepam, 2 mg of clonazepam, and 15 mg of gabapentin per day. After epidural catheterization for the postoperative analgesia, general anesthesia was induced and maintained with continuous remifentanil infusion and propofol with target controlled infusion. With train-of-four ratio (TOFR) monitoring by stimulating the ulnar nerve, her trachea was intubated after 0.6mg x kg(-1) of rocuronium intravenous administration. Since then, additional rocuronium was not given for 4 hours. After surgery, she was fully awake and TOFR recovered to 100%, but tidal volume was too low to remove the tracheal tube, and mechanical ventilation was continued in ICU. On the next day, the tracheal tube was removed, and she was discharged from ICU. Because anesthetics may delay the recovery of respiratory function in a patient with stiff-person syndrome, careful assessment of respiratory function is needed at the emergence from general anesthesia.

  2. Efficacy of articaine: a new amide local anesthetic.

    Science.gov (United States)

    Malamed, S F; Gagnon, S; Leblanc, D

    2000-05-01

    The authors compared the safety and efficacy of 4 percent articaine with epinephrine 1:100,000 with 2 percent lidocaine with epinephrine 1:100,000. In three identical randomized, double-blind, multicenter trials, subjects 4 to 80 years of age received either 4 percent articaine with epinephrine 1:100,000 or 2 percent lidocaine with epinephrine 1:100,000 for simple or complex dental procedures. In each trial, the authors randomized the subjects in a 2:1 ratio to receive articaine or lidocaine. Efficacy was determined by both subject and investigator using a visual analog scale, or VAS. The authors used the Kruskal-Wallis test to analyze the data. A total of 882 subjects received articaine, and 443 received lidocaine. The authors found no statistical differences between the groups (P = .05). They also compared drug volumes for both articaine and lidocaine groups (2.5 milliliters +/- 0.07 standard error of mean, or SEM, vs. 2.6 mL +/- 0.09 SEM for simple procedures and 4.2 mL +/- 0.15 SEM vs. 4.5 mL +/- 0.21 SEM for complex procedures). The procedures' durations were comparable for both the articaine and lidocaine groups. The authors found no statistical difference between the two treatment groups (P = .05) with respect to subject or investigator pain ratings using the VAS; the mean pain scores determined by both patients and investigators for all groups tested were less than 1.0. The authors found that 4 percent articaine with epinephrine 1:100,000 was well-tolerated in 882 subjects. It also provided clinically effective pain relief during most dental procedures and had a time to onset and duration of anesthesia appropriate for clinical use and comparable to those observed for other commercially available local anesthetics. Pain control is a major component of patient comfort and safety. Local anesthetics form the backbone of pain control techniques in dentistry. Four percent articaine with epinephrine is an amide local anesthetic that will meet the clinical

  3. Nonpreserved amniotic membrane transplantation for bilateral toxic keratopathy caused by topical anesthetic abuse: a case report

    Directory of Open Access Journals (Sweden)

    Altinok Ayse

    2010-08-01

    Full Text Available Abstract Introduction Corneal damage associated with abuse of topical anesthetics is a rare clinic entity. Topical anesthetic abuse is one of the causes of ring keratitis. Ring keratitis is easily overlooked because it can mimic acanthamoeba keratitis or other infectious keratitis. The outcome is often poor, leading to persistent epithelial defects, corneal scarring, and perforations. Case presentation We report the clinical presentation, diagnosis, and treatment of a 65-year-old Caucasian man, who worked as a health care worker, with bilateral toxic keratopathy caused by topical anesthetic abuse. Nonpreserved amniotic membrane transplantation was performed for both eyes of the patient. Conclusion It is important to identify and treat patients who abuse topical anesthetics before permanent vision loss ensues. Nonpreserved amniotic membrane transplantation may be useful in relieving pain and improving corneal surface in anesthetic agent abusers.

  4. Quantitative estimates of the volatility of ambient organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2010-01-01

    results also show that the amount of semivolatile gas-phase organics in equilibrium with the OA could range from ~20% to 400% of the OA mass, with smaller values generally corresponding to the higher ΔHvap assumptions. The volatility of various OA components determined from factor analysis of AMS spectra has also been assessed. In general, it is found that the fraction of non-volatile material follows the pattern: biomass burning OA < hydrocarbon-like OA < semivolatile oxygenated OA < low-volatility oxygenated OA. Correspondingly, the sensitivity to dilution and the estimated amount of semivolatile gas-phase material for the OA factors follows the reverse order. Primary OA has a substantial semivolatile fraction, in agreement with previous results, while the non-volatile fraction appears to be dominated by oxygenated OA produced by atmospheric aging. The overall OA volatility is thus controlled by the relative contribution of each aerosol type to the total OA burden. Finally, the model/measurement comparison appears to require OA having an evaporation coefficient (γe substantially greater than 10−2; at this point it is not possible to place firmer constraints on γe based on the observations.

  5. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    to the multivariate case of the univariate level shift technique by Lu and Perron (2008). An application to the S&P500 index and a simulation experiment show that the recently documented empirical properties of strong persistence in volatility and forecastability of future realized volatility from current implied...... volatility, which have been interpreted as long memory (or fractional integration) in volatility and fractional cointegration between implied and realized volatility, are accounted for by occasional common level shifts....

  6. Anesthetic management of Morgagni hernia repair in an elderly woman.

    Science.gov (United States)

    Nama, Rajnish K; Butala, Bina P; Shah, Veena R; Patel, Hiren R

    2015-01-01

    Adult onset congenital diaphragmatic hernia (CDH) is uncommon but not rare. Morgagni hernia is a rare variant of CDH. The defect tends to be small and patients may remain asymptomatic and diagnosed incidentally. When these patients become symptomatic, they usually present with gastrointestinal and cardiorespiratory symptoms or sometimes as an emergency due to obstruction or strangulation of herniated viscera. Chest radiograph, computed tomography scan, and magnetic resonance imaging are the imaging modalities used for diagnosis of CDH. Cardiopulmonary compromise due to mass effect of hernial contents on lungs, heart and great vessels, and obstruction or strangulation of herniated viscera poses the special challenge before anesthesiologists. Our patient was diagnosed to have Morgagni hernia, at the age of 72 years and underwent laparotomy for the same. This case highlights the key feature of the successful anesthetic management of adult onset CDH.

  7. Dental anesthetic management of a patient with ventricular arrhythmias.

    Science.gov (United States)

    Miller, R A; Siegelman, L I

    1998-01-01

    During routine deep sedation for endodontic therapy, a dentist-anesthesiologist observed premature ventricular contractions (PVCs) on a 62-yr-old woman's electrocardiogram (EKG) tracing. The dentist was able to complete the root canal procedure under intravenous (i.v.) sedation without any problems. The dentist-anesthesiologist referred the patient for medical evaluation. She was found to be free from ischemic cardiac disease with normal ventricular function. The patient was cleared to continue her dental treatment with deep sedation. She subsequently continued to undergo dental treatment with deep intravenous sedation without incident, although her EKG exhibited frequent PVCs, up to 20 per minute, including couplets and episodes of trigeminy. This article will review indications for medical intervention, antiarrhythmic medications, and anesthetic interventions for perioperative PVCs.

  8. Anticholeretic effect of substance P in anesthetized dogs.

    Science.gov (United States)

    Holm, I; Thulin, L; Hellgren, M

    1978-03-01

    Nine anesthetized dogs were provided with acute common duct fistulas after exclusion of the gallbladder. Synthetic Substance P was administered as caval infusions in a dosage of 0.5-20 ng x kg-1 x min-1, duration 10 min. The output of hepatic bile, sodium and amylase decreased during infusion by 40-52 per cent at the highest doses. After termination of infusion all 3 parameters increased by 19-60 per cent above the basal level. The biliary concentration of sodium was constant, while that of amylase increased during infusion. The responses were dose-related. The anticholeresis induced by substance P might be due to inhibition of the canalicular bile fraction, which presumably is mediated by active sodium transport and independent of bile salt excretion.

  9. Anesthetic management of robot-assisted thoracoscopic thymectomy

    Directory of Open Access Journals (Sweden)

    Anil Karlekar

    2016-01-01

    Full Text Available Myasthenia gravis (MG is a rare disorder involving neuromuscular junction. In conjunction with medical therapy, thymectomy is a known modality of treatment of MG and has shown to increase the probability of remission and overall symptomatic improvement. For minimally invasive thymectomy, video-.assisted thoracoscopic surgery has been the preferred surgical approach till recently. The robotic surgical procedure must necessarily bring new challenges to the anesthesiologists to effectively meet the specific requirements of the technique. At present, there is a paucity of literature regarding the anesthetic concerns of robotic assisted thymectomy, patient in question specifically posed a challenge since different maneuvers and techniques had to be tried to obtain optimum surgical conditions with stable ventilatory and hemodynamic parameters. Concerns of patient positioning and hemodynamic monitoring have also been discussed.

  10. Electrocardiographic evaluation of two anesthetic combinations in dogs

    Directory of Open Access Journals (Sweden)

    Tárraga K.M.

    2000-01-01

    Full Text Available This study aimed to investigate electrocardiographic changes in dogs aged 5 years or more submitted to two anesthetic combinations: atropine, levomeprazine, thiopental and halothane (ALTH, and atropine, tiletamine and zolazepam (ATZ. Forty dogs (24 males/16 females weighing 5-24kg, were used. Dogs had no cardiac problems and were submitted to tartarectomy. All animals were submitted to two electrocardiograms (ECG, one before anesthesia and other immediately before surgery. The dogs were divided into two groups: group 1 received ALTH and group 2 received ATZ. Alterations in the ST segment, T wave, cardiac rhythm and a significant reduction of vagal tonus index were observed in both groups, but in group 2 a significant reduction of the PR and QT intervals and an increase in heart rate were also observed. These data suggest that the ALTH combination caused fewer changes in the ECG than the ATZ combination.

  11. Carcinoid tumors: Challenges and considerations during anesthetic management

    Directory of Open Access Journals (Sweden)

    Sukhminder Jit Singh Bajwa

    2015-01-01

    Full Text Available Carcinoid tumors are rare, slow-growing neoplasms of neuroendocrine tissues from enterochromaffin or kulchitsky cells, which have the potential to metastasize. The mediators released from these tumors when bypass the hepatic metabolism, can lead to the possible development of carcinoid syndrome. This is a life-threatening complication, which can lead to profound hemodynamic instability, especially in a peri-operative period, when the patient is exposed to various types of noxious stimuli. Off late, use of octreotide, a synthetic analog of somatostatin, has significantly reduced the peri-operative morbidity and mortality. The current review discusses the various anesthetic challenges and considerations during peri-operative management of carcinoid tumors.

  12. Eugenol as an anesthetic for juvenile common snook

    Directory of Open Access Journals (Sweden)

    Jurandir Joaquim Bernardes Júnior

    2013-08-01

    Full Text Available The objective of this work was to evaluate the efficacy of eugenol as an anesthetic for juvenile common snook, and to determine the minimum effective concentration for use in handling procedures. In the first trial, juvenile common snook were subjected to immersion baths at 25, 50, 75, 100, 125, and 150 mg L-1 eugenol concentrations, after which induction and recovery times were evaluated. In the second experiment, the lethal exposure time (LT50 at 75 mg L-1 was estimated. Minimum effective eugenol concentration was 50 mg L-1, andthe stage of deep anesthesia and recovery were, respectively, reached at 126.3 and 208.8 s. At 75 mg L-1, LT50 was 1,314 s, and induction time and recovery were also satisfactory; however, fish cannot tolerate over 229 s exposure.

  13. GABAA Receptors, Anesthetics and Anticonvulsants in Brain Development

    Science.gov (United States)

    Henschel, Oliver; Gipson, Keith E.; Bordey, Angelique

    2008-01-01

    GABA, acting via GABAA receptors, is well-accepted as the main inhibitory neurotransmitter of the mature brain, where it dampens neuronal excitability. The receptor's properties have been studied extensively, yielding important information about its structure, pharmacology, and regulation that are summarized in this review. Several GABAergic drugs have been commonly used as anesthetics, sedatives, and anticonvulsants for decades. However, findings that GABA has critical functions in brain development, in particular during the late embryonic and neonatal period, raise worthwhile questions regarding the side effects of GABAergic drugs that may lead to long-term cognitive deficits. Here, we will review some of these drugs in parallel with the control of CNS development that GABA exerts via activation of GABAA receptors. This review aims to provide a basic science and clinical perspective on the function of GABA and related pharmaceuticals acting at GABAA receptors. PMID:18537647

  14. The effects of anesthetic agents on oxidative stress

    Science.gov (United States)

    Yakan, Selvinaz; Düzgüner, Vesile

    2016-04-01

    Oxidative stress can be defined as the instability between antioxidant defense of the body and the production of free radical that causes peroxydation on the lipid layer. Free radicals are reactive oxygen species that are produced in the course of normal metabolisms of aerobe organisms and they may cause disorders in cell structure and organelles by interacting macromolecules, like lipid, protein, nucleic acids. Therefore, they may cause cardiovascular, immune system, liver, kidney illnesses and many other illnesses like cancer, aging, cataract, diabetes. It is known that many drugs used for the purpose of anesthetizing may cause lipid peroxidation in organism. For these reasons, determining the Oxidative stress index of anaesthetic stress chosen in the ones that are exposed to long term anaesthetic agents and anaesthesia appliccations, is so substantial.

  15. Anesthetic management of laparoscopic pheochromocytoma surgery: A case report

    Directory of Open Access Journals (Sweden)

    Hakan Akelma

    2014-06-01

    Full Text Available Pheochromocytoma is a neuroendocrine tumor of the adrenal medulla chromaffin cells. It has a variable clinic indicating symptoms such as hypertension, headache, sweating, palpitations, and anxiety. Determination of vanillylmandelic acid in urine and metanephrines are accepted as the most sensitive tests for diagnosis. Computerized tomography and magnetic resonance imaging cad be used for tumor localization. Anesthetic induction and surgical manipulations usually lead to the catastrophic release of catecholamines. Thus, accurate preoperative pharmacological preparation is vital in these patients. Treatment is a complete surgical resection of the primary tumor and, if possible, metastases after banning dangerous fluctuations in hemodynamic through α-blockers. Today, laparoscopic adrenalectomy has begun to replace open surgery as a standard treatment method in many adrenal diseases. J Clin Exp Invest 2014; 5 (2: 443-446

  16. Improved exposure estimation in soil screening and clean-up criteria for volatile organic chemicals.

    Science.gov (United States)

    DeVaull, George E

    2017-02-18

    Soil clean-up criteria define acceptable concentrations of organic chemical constituents for exposed humans. These criteria sum the estimated soil exposure over multiple pathways. Assumptions for ingestion, dermal contact, and dust exposure generally presume a chemical persists in surface soils at a constant concentration level for the entire exposure duration. For volatile chemicals this is an unrealistic assumption. A calculation method is presented for surficial soil criteria which include volatile depletion of chemical for these uptake pathways. The depletion estimates compare favorably with measured concentration profiles and with field measurements of soil concentration. Corresponding volatilization estimates compare favorably with measured data for a wide range of volatile and semi-volatile chemicals, including instances with and without the presence of a mixed-chemical residual phase. Selected examples show application of the revised factors in estimating screening levels for benzene in surficial soils. This article is protected by copyright. All rights reserved.

  17. The Oxygen and Volatile Extraction Node (OVEN) Subsystem for Resource Prospector

    Science.gov (United States)

    Paz, Aaron; Oryshchyn, Lara

    2014-01-01

    The OVEN (Oxygen and Volatile Extraction Node) Subsystem is part of the RESOLVE (Regolith and Environment Science & Oxygen and Lunar Volatile Extraction) Payload, whose main objective is to verify the presence of water and other volatiles on the lunar surface. The RESOLVE payload is scheduled to fly to the moon as part of the Resource Prospector (RP) in 2019. The OVEN Subsystem accepts regolith (soil) and evolves the volatiles contained in the sample by heating the segment to a temperature of at least 150oC for volatile analysis and as high as 900oC for hydrogen reduction. In general, a regolith segment is deposited into a crucible; the crucible is heated and evolved gases flow to a gas analyzer.

  18. A study about the existence of the leverage effect in stochastic volatility models

    Science.gov (United States)

    Florescu, Ionuţ; Pãsãricã, Cristian Gabriel

    2009-02-01

    The empirical relationship between the return of an asset and the volatility of the asset has been well documented in the financial literature. Named the leverage effect or sometimes risk-premium effect, it is observed in real data that, when the return of the asset decreases, the volatility increases and vice versa. Consequently, it is important to demonstrate that any formulated model for the asset price is capable of generating this effect observed in practice. Furthermore, we need to understand the conditions on the parameters present in the model that guarantee the apparition of the leverage effect. In this paper we analyze two general specifications of stochastic volatility models and their capability of generating the perceived leverage effect. We derive conditions for the apparition of leverage effect in both of these stochastic volatility models. We exemplify using stochastic volatility models used in practice and we explicitly state the conditions for the existence of the leverage effect in these examples.

  19. Hypotensive property of Chenopodium ambrosioides in anesthetized normotensive rats.

    Science.gov (United States)

    Assaidi, Asmae; Legssyer, Abdelkhaleq; Berrichi, Abdelbasset; Aziz, Mohammed; Mekhfi, Hassane; Bnouham, Mohammed; Ziyyat, Abderrahim

    2014-02-20

    The leaves of Chenopodium ambrosioides L. (Chenopodiaceae) are widely used in Moroccan traditional medicine to treat diabetes and hypertension. The goal of the present work is to investigate the hypotensive properties of different extract and fractions of the plant in anesthetized normotensive rats and to elucidate the mechanism underlying this effect. The hypotensive effect of aqueous extract (AqE) of the leaves of C. ambrosioides L., methanolic (MF), ethyl acetate (AcF), and aqueous (AqF) Soxhlet fractions, administrated intravenously, was evaluated in anesthetized rats. The recorded signals of blood pressure and heart rate were visualized and analyzed by using an acquisition card "National Instrument" and software Labview 6.1. Intravenous administration of AqE of the leaves of C. ambrosioides L. induces a dose-dependent hypotension. A similar effect was obtained with MF, AcF, and AqF. Atropine (1 mg/kg), used to block cholinergic system, significantly reduced the hypotensive response to MF and AcF suggesting the presence of the cholinomimetic-muscarinic components in these fractions. However, the blood pressure lowering effect of MF and AcF in rats pretreated with L-NAME 20 mg/kg was unchanged showing that the release of NO is not implicated in the hypotensive action of this plant. The present study demonstrates that extracts from leaves of C. ambrosioides induce hypotensive effect that may be partially associated with its cardiac effects. These results may partly explain the traditional use of leaves of C. ambrosioides L. for the treatment of disorders such as hypertension.

  20. From micro- to nanostructured implantable device for local anesthetic delivery.

    Science.gov (United States)

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies