Biological production of ethanol from waste gases with Clostridium ljungdahlii

DOEpatents

Gaddy, James L.

2000-01-01

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products is disclosed. The method includes introducing the waste gases into a bioreactor where they are fermented to various product, such as organic acids, alcohols H.sub.2, SCP, and salts of organic acids by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified.

Greenhouse gases emission from municipal waste management: The role of separate collection.

PubMed

Calabrò, Paolo S

2009-07-01

The municipal solid waste management significantly contributes to the emission in the atmosphere of greenhouse gases (e.g. CO(2), CH(4), N(2)O) and therefore the management process from collection to treatment and disposal has to be optimized in order to reduce these emissions. In this paper, starting from the average composition of undifferentiated municipal solid waste in Italy, the effect of separate collection on greenhouse gases emissions from municipal waste management has been assessed. Different combinations of separate collection scenarios and disposal options (i.e. landfilling and incineration) have been considered. The effect of energy recovery from waste both in landfills and incinerators has also been addressed. The results outline how a separate collection approach can have a significant effect on the emission of greenhouse gases and how wise municipal solid waste management, implying the adoption of Best Available Technologies (i.e. biogas recovery and exploitation system in landfills and energy recovery system in Waste to Energy plants), can not only significantly reduce greenhouse gases emissions but, in certain cases, can also make the overall process a carbon sink. Moreover it has been shown that separate collection of plastic is a major issue when dealing with global warming relevant emissions from municipal solid waste management.

Aerobic Food Waste Composting: Measurement of Green House Gases

NASA Astrophysics Data System (ADS)

Chung, J.

2016-12-01

Greenhouse gases (GHGs) are a major cause of global warming. While food waste composting can reduce the amount of waste being sent to traditional landfills, it also produces GHGs during the process. The objective of this research is to evaluate the GHGs emitted from an aerobic food composting machine, which is used in ISF. The Independent Schools Foundation Academy is a private independent school in Hong Kong with approximately 1500 students. Each academic year, the school produces 27 metric tons of food waste. In November 2013, the school installed a food waste composting system. Over the past 3 years, various improvements, such as installing a bio-filter to reduce the smell of the compost, have been made to the composting process. Meanwhile the compost is used by the primary students, as part of their experiential learning curriculum and organic farming projects. The composting process employs two machines: the Dehydra and A900 Rocket. The Dehydra reduces the mass of the food waste by separating the ground food waste and excessive water. The A900 Rocket, a composter made by Tidy Planet, processes food waste into compost in 14 days. This machine runs in an aerobic process, in which oxygen is used as an input gas and gases, such as carbon dioxide, are released. Carbon Dioxide is one of the greenhouse gases (GHGs). This research focuses on GHGs that are emitted from the A900 Rocket. The data is collected by the Gasmet DX 4015, a Fourier transform infrared spectroscopy (FTIR) multi gas analyser. This equipment measures the concentration (ppm) of different GHGs, including N2O, CO2, CH4, NH3 and CO.

Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nimbalkar, Sachin U; Thekdi, Arvind; Keiser, James R

2014-01-01

This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electricmore » arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.« less

Specific inhibition of antenna bacteriochlorophyll synthesis in Chlorobium vibrioforme by anesthetic gases.

PubMed Central

Ormerod, J G; Nesbakken, T; Beale, S I

1990-01-01

The green sulfur bacterium Chlorobium vibrioforme contains two types of bacteriochlorophyll (Bchl). The minor pigment, Bchl a, is associated primarily with the cell membrane and its reaction centers; and the major light-harvesting antenna pigment, Bchl d, is found primarily in the chlorosomes, which are attached to the inner surface of the cell membrane. Anesthetic gases, such as N2O, ethylene, and acetylene, were found to inhibit the synthesis of Bchl d, but not of Bchl a, thus allowing the cells to grow at high light intensities with a greatly diminished content of antenna pigment. Chlorosomes were absent or sparse in inhibited cells. Porphyrins accumulated in the inhibited cells. The major one was identified as the Bchl precursor magnesium-protoporphyrin IX monomethyl ester (Mg-PPME) by comparative absorption and fluorescence spectroscopy and thin-layer chromatography of the porphyrin and its derivatives with those of authentic protoporphyrin IX. Small amounts of Mg-PPME were present in control cells, but the addition of inhibitor caused a rapid increase in the Mg-PPME concentration, accompanying the inhibition of Bchl d synthesis. Cells grown in the presence of ethephon (as a source of ethylene) and allowed to stand in dim light for long periods accumulated large amounts of PPME and other porphyrins and excreted or released porphyrins, which accumulated as a brown precipitate in the culture. Inhibition of Bchl d synthesis was relieved upon removal of the inhibitor. These results suggest that the gases act at a step in pigment biosynthesis that affects the utilization of Mg-PPME for isocyclic ring formation. Synthesis of Bchl d and Bchl a may be differentially affected by the gases because of compartmentation of their biosynthetic apparatus or because competition for precursors favors Bchl a synthesis. An ethephon-resistant mutant strain was isolated by selection for growth in dim, long-wavelength light. The mutant cells were also resistant to acetylene, but not

Catalytic dry reforming of waste plastics from different waste treatment plants for production of synthesis gases.

PubMed

Saad, Juniza Md; Williams, Paul T

2016-12-01

Catalytic dry reforming of mixed waste plastics, from a range of different municipal, commercial and industrial sources, were processed in a two-stage fixed bed reactor. Pyrolysis of the plastics took place in the first stage and dry (CO 2 ) reforming of the evolved pyrolysis gases took place in the second stage in the presence of Ni/Al 2 O 3 and Ni-Co/Al 2 O 3 catalysts in order to improve the production of syngas from the dry reforming process. The results showed that the highest amount of syngas yield was obtained from the dry reforming of plastic waste from the agricultural industry with the Ni/Al 2 O 3 catalyst, producing 153.67mmol syngas g -1 waste . The addition of cobalt metal as a promoter to the Ni/Al 2 O 3 catalyst did not have a major influence on syngas yield. Overall, the catalytic-dry reforming of waste plastics from various waste treatment plants showed great potential towards the production of synthesis gases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clostridium stain which produces acetic acid from waste gases

DOEpatents

Gaddy, James L.

1997-01-01

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Clostridium strain which produces acetic acid from waste gases

DOEpatents

Gaddy, J.L.

1997-01-14

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 4 figs.

40 CFR 60.54a - Standard for municipal waste combustor acid gases.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for Municipal Waste Combustors for Which Construction Is Commenced After December 20, 1989 and On or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) [Reserved... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for municipal waste combustor...

Greenhouse gases accounting and reporting for waste management--a South African perspective.

PubMed

Friedrich, Elena; Trois, Cristina

2010-11-01

This paper investigates how greenhouse gases are accounted and reported in the waste sector in South Africa. Developing countries (including South Africa) do not have binding emission reduction targets, but many of them publish different greenhouse gas emissions data which have been accounted and reported in different ways. Results show that for South Africa, inventories at national and municipal level are the most important tools in the process of accounting and reporting greenhouse gases from waste. For the development of these inventories international initiatives were important catalysts at national and municipal levels, and assisted in developing local expertise, resulting in increased output quality. However, discrepancies in the methodology used to account greenhouse gases from waste between inventories still remain a concern. This is a challenging issue for developing countries, especially African ones, since higher accuracy methods are more data intensive. Analysis of the South African inventories shows that results from the recent inventories can not be compared with older ones due to the use of different accounting methodologies. More recently the use of Clean Development Mechanism (CDM) procedures in Africa, geared towards direct measurements of greenhouse gases from landfill sites, has increased and resulted in an improvement of the quality of greenhouse gas inventories at municipal level. Copyright © 2010 Elsevier Ltd. All rights reserved.

Distribution of gases in the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois

USGS Publications Warehouse

Striegl, Robert G.

1988-01-01

The unsaturated zone is a medium that provides pneumatic communication for the movement of gases from wastes buried in landfills to the atmosphere, biota, and groundwater. Gases in unsaturated glacial and eolian deposits near a waste-disposal trench at the low-level radioactive-waste disposal site near Sheffield, Bureau County, Illinois, were identified, and the spatial and temporal distributions of the partial pressures of those gases were determined for the period January 1984 through January 1986. Methods for the collection and analyses of the gases are described, as are geologic and hydrologic characteristics of the unsaturated zone that affect gas transport. The identified gases, which are of natural and of waste origin, include nitrogen, oxygen, and argon, carbon dioxide, methane, propane, butane, tritiated water vapor, 14carbon dioxide, and 222 radon. Concentrations of methane and 14carbon dioxide originated at the waste, as shown by partial-pressure gradients of the gases; 14carbon dioxide partial pressures exceeded natural background partial pressures by factors greater than 1 million at some locations. Variations in partial pressures of oxygen and carbon dioxide were seasonal among piezometers because of increased root and soil-microbe respiration during summer. Variations in methane and 14carbon dioxide partial pressures were apparently related to discrete releases from waste sources at unpredictable intervals of time. No greater than background partial pressures for tritiated water vapor or 222 radon were measured. (USGS)

Performance of an electrochemical carbon monoxide monitor in the presence of anesthetic gases.

PubMed

Dunning, M; Woehlck, H J

1997-11-01

The passage of volatile anesthetic agents through accidentally dried CO2 absorbents in anesthesia circuits can result in the chemical breakdown of anesthetics with production of greater than 10000 ppm carbon monoxide (CO). This study was designed to evaluate a portable CO monitor in the presence of volatile anesthetic agents. Two portable CO monitors employing electrochemical sensors were tested to determine the effects of anesthetic agents, gas sample flow rates, and high CO concentrations on their electrochemical sensor. The portable CO monitors were exposed to gas mixtures of 0 to 500 ppm CO in either 70% nitrous oxide, 1 MAC concentrations of contemporary volatile anesthetics, or reacted isoflurane or desflurane (containing CO and CHF3) in oxygen. The CO measurements from the electrochemical sensors were compared to simultaneously obtained samples measured by gas chromatography (GC). Data were analyzed by linear regression. Overall correlation between the portable CO monitors and the GC resulted in an r2 value >0.98 for all anesthetic agents. Sequestered samples produced an exponential decay of measured CO with time, whereas stable measurements were maintained during continuous flow across the sensor. Increasing flow rates resulted in higher CO readings. Exposing the CO sensor to 3000 and 19000 ppm CO resulted in maximum reported concentrations of approximately 1250 ppm, with a prolonged recovery. Decrease in measured concentration of the sequestered samples suggests destruction of the sample by the sensor, whereas a diffusion limitation is suggested by the dependency of measured value upon flow. Any value over 500 ppm must be assumed to represent dangerous concentrations of CO because of the non-linear response of these monitors at very high CO concentrations. These portable electrochemical CO monitors are adequate to measure CO concentrations up to 500 ppm in the presence of typical clinical concentrations of anesthetics.

Relationship between potency and boiling point of general anesthetics: a thermodynamic consideration.

PubMed

Dastmalchi, S; Barzegar-Jalali, M

2000-07-20

The most important group of nonspecific drugs is that of the general anesthetics. These nonspecific compounds vary greatly in structure, from noble gases such as Ar or Xe to complex steroids. Since the development of clinical anesthesia over a century ago, there has been a vast amount of research and speculation concerning the mechanism of action of general anesthetics. Despite these efforts, the exact mechanism remains unknown. Many theories of narcosis do not explain how unconsciousness is produced at a molecular level, but instead relate some physicochemical property of anesthetic agents to their anesthetic potencies. In this paper, we address some of those physicochemical properties, with more emphasis on correlating the anesthetic potency of volatile anesthetics to their boiling points based on thermodynamic principles.

Biological production of acetic acid from waste gases with Clostridium ljungdahlii

DOEpatents

Gaddy, James L.

1998-01-01

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Biological production of acetic acid from waste gases with Clostridium ljungdahlii

DOEpatents

Gaddy, J.L.

1998-09-15

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 5 figs.

Global emissions of trace gases, particulate matter, and hazardous air pollutants from open burning of domestic waste.

PubMed

Wiedinmyer, Christine; Yokelson, Robert J; Gullett, Brian K

2014-08-19

The open burning of waste, whether at individual residences, businesses, or dump sites, is a large source of air pollutants. These emissions, however, are not included in many current emission inventories used for chemistry and climate modeling applications. This paper presents the first comprehensive and consistent estimates of the global emissions of greenhouse gases, particulate matter, reactive trace gases, and toxic compounds from open waste burning. Global emissions of CO2 from open waste burning are relatively small compared to total anthropogenic CO2; however, regional CO2 emissions, particularly in many developing countries in Asia and Africa, are substantial. Further, emissions of reactive trace gases and particulate matter from open waste burning are more significant on regional scales. For example, the emissions of PM10 from open domestic waste burning in China is equivalent to 22% of China's total reported anthropogenic PM10 emissions. The results of the emissions model presented here suggest that emissions of many air pollutants are significantly underestimated in current inventories because open waste burning is not included, consistent with studies that compare model results with available observations.

Simultaneous treatment of SO2 containing stack gases and waste water

NASA Technical Reports Server (NTRS)

Poradek, J. C.; Collins, D. D. (Inventor)

1978-01-01

A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

Abatement of waste gases and water during the processes of semiconductor fabrication.

PubMed

Wen, Rui-mei; Liang, Jun-wu

2002-10-01

The purpose of this article is to examine the methods and equipment for abating waste gases and water produced during the manufacture of semiconductor materials and devices. Three separating methods and equipment are used to control three different groups of electronic wastes. The first group includes arsine and phosphine emitted during the processes of semiconductor materials manufacture. The abatement procedure for this group of pollutants consists of adding iodates, cupric and manganese salts to a multiple shower tower (MST) structure. The second group includes pollutants containing arsenic, phosphorus, HF, HCl, NO2, and SO3 emitted during the manufacture of semiconductor materials and devices. The abatement procedure involves mixing oxidants and bases in an oval column with a separator in the middle. The third group consists of the ions of As, P and heavy metals contained in the waste water. The abatement procedure includes adding CaCO3 and ferric salts in a flocculation-sedimentation compact device equipment. Test results showed that all waste gases and water after the abatement procedures presented in this article passed the discharge standards set by the State Environmental Protection Administration of China.

Pharmacoeconomics of inhaled anesthetic agents: considerations for the pharmacist.

PubMed

Chernin, Eric L

2004-10-15

Types of economic analyses used for inhaled anesthetic agents, factors to consider in calculating the cost of inhaled anesthetics, limitations of pharmacoeconomic studies of these agents, and strategies for controlling inhaled anesthetic costs are discussed. Inhaled anesthetic agents comprise a substantial component of drug budgets. Calculation of the cost of administering an inhaled anesthetic should take into consideration the cost per mL, potency, waste, concentration and duration of gas delivery, fresh gas flow rate, molecular weight, and density. The use of newer inhaled anesthetic agents with low solubility in blood and tissue provides a more rapid recovery from anesthesia than older, more soluble agents, and also provides the same level of control of depth of anesthesia at a lower fresh gas flow rate and possibly a lower cost than older agents at a higher fresh gas flow rate. A more rapid recovery may facilitate fast-track recovery and yield cost savings if it allows the completion of additional surgical cases or allows a reduction in personnel overtime expenses. Interpretation of pharmacoeconomic studies of inhaled anesthetics requires an appreciation of the limitations in methodology and ability to extrapolate results from one setting to another. Pharmacists' efforts to reduce anesthetic waste and collaborate with anesthesiologists to improve the use of these agents can help contain costs, but improving scheduling and efficiency in the operating room has a greater potential to reduce operating room costs. Much can be done to control costs of anesthetic agents without compromising availability of these agents and patient care.

Isoflurane waste anesthetic gas concentrations associated with the open-drop method.

PubMed

Taylor, Douglas K; Mook, Deborah M

2009-01-01

The open-drop technique is used frequently for anesthetic delivery to small rodents. Operator exposure to waste anesthetic gas (WAG) is a potential occupational hazard if this method is used without WAG scavenging. This study was conducted to determine whether administration of isoflurane by the open-drop technique without exposure controls generates significant WAG concentrations. We placed 0.1, 0.2, or 0.3 ml of liquid isoflurane into screw-top 500 or 1000 ml glass jars. WAG concentration was measured at the opening of the container and 20 and 40 cm from the opening, a distance at which users likely would operate, at 1, 2, or 3 min WAG was measured by using a portable infrared gas analyzer. Mean WAG concentrations at the vessel opening were as high as 662 +/- 168 ppm with a 500 ml jar and 122 +/- 87 ppm with a 1000 ml jar. At operator levels, WAG concentrations were always at or near 0 ppm. For measurements made at the vessel opening, time was the only factor that significantly affected WAG concentration when using the 500 ml jar. Neither time nor liquid volume were significant factors when using 1000 ml jar. At all liquid volumes and time points, the WAG concentration associated with using the 500 ml container was marginally to significantly greater than that for the 1000 ml jar.

Process engineering design of pathological waste incinerator with an integrated combustion gases treatment unit.

PubMed

Shaaban, A F

2007-06-25

Management of medical wastes generated at different hospitals in Egypt is considered a highly serious problem. The sources and quantities of regulated medical wastes have been thoroughly surveyed and estimated (75t/day from governmental hospitals in Cairo). From the collected data it was concluded that the most appropriate incinerator capacity is 150kg/h. The objective of this work is to develop the process engineering design of an integrated unit, which is technically and economically capable for incinerating medical wastes and treatment of combustion gases. Such unit consists of (i) an incineration unit (INC-1) having an operating temperature of 1100 degrees C at 300% excess air, (ii) combustion-gases cooler (HE-1) generating 35m(3)/h hot water at 75 degrees C, (iii) dust filter (DF-1) capable of reducing particulates to 10-20mg/Nm(3), (iv) gas scrubbers (GS-1,2) for removing acidic gases, (v) a multi-tube fixed bed catalytic converter (CC-1) to maintain the level of dioxins and furans below 0.1ng/Nm(3), and (vi) an induced-draft suction fan system (SF-1) that can handle 6500Nm(3)/h at 250 degrees C. The residence time of combustion gases in the ignition, mixing and combustion chambers was found to be 2s, 0.25s and 0.75s, respectively. This will ensure both thorough homogenization of combustion gases and complete destruction of harmful constituents of the refuse. The adequate engineering design of individual process equipment results in competitive fixed and operating investments. The incineration unit has proved its high operating efficiency through the measurements of different pollutant-levels vented to the open atmosphere, which was found to be in conformity with the maximum allowable limits as specified in the law number 4/1994 issued by the Egyptian Environmental Affairs Agency (EEAA) and the European standards.

Control of Effluent Gases from Solid Waste Processing using Impregnated Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Li, Jing; Fisher, John; Wignarajah, Kanapathipillai

2005-01-01

One of the major problems associated with solid waste processing technologies is effluent contaminants that are released in gaseous forms from the processes. This is a concern in both biological as well as physicochemical solid waste processing. Carbon dioxide (CO2), the major gas released, does not present a serious problem and there are currently in place a number of flight-qualified technologies for CO2 removal. However, a number of other gases, in particular NOx, SO2, NH3, and various hydrocarbons (e.g. CH4) do present health hazards to the crew members in space habitats. In the present configuration of solid waste processing in the International Space Station (ISS), some of these gases are removed by the Trace Contaminant Control System (TCCS), demands a major resupply. Reduction of the resupply can be effective by using catalyst impregnated carbon nanotubes. For example, NO decomposition to N2 and O2 is thermodynamically favored. Data showing decomposition of NO on metal impregnated carbon nanotubes is presented. Comparisons are made of the existing TCCS systems with the carbon nanotube based technology for removing NOx based on mass/energy penalties.

Anesthetics act in quantum channels in brain microtubules to prevent consciousness.

PubMed

Craddock, Travis J A; Hameroff, Stuart R; Ayoub, Ahmed T; Klobukowski, Mariusz; Tuszynski, Jack A

2015-01-01

The mechanism by which anesthetic gases selectively prevent consciousness and memory (sparing non-conscious brain functions) remains unknown. At the turn of the 20(th) century Meyer and Overton showed that potency of structurally dissimilar anesthetic gas molecules correlated precisely over many orders of magnitude with one factor, solubility in a non-polar, 'hydrophobic' medium akin to olive oil. In the 1980s Franks and Lieb showed anesthetics acted in such a medium within proteins, suggesting post-synaptic membrane receptors. But anesthetic studies on such proteins yielded only confusing results. In recent years Eckenhoff and colleagues have found anesthetic action in microtubules, cytoskeletal polymers of the protein tubulin inside brain neurons. 'Quantum mobility' in microtubules has been proposed to mediate consciousness. Through molecular modeling we have previously shown: (1) olive oil-like non-polar, hydrophobic quantum mobility pathways ('quantum channels') of tryptophan rings in tubulin, (2) binding of anesthetic gas molecules in these channels, and (3) capabilities for π-electron resonant energy transfer, or exciton hopping, among tryptophan aromatic rings in quantum channels, similar to photosynthesis protein quantum coherence. Here, we show anesthetic molecules can impair π-resonance energy transfer and exciton hopping in tubulin quantum channels, and thus account for selective action of anesthetics on consciousness and memory.

[Calibration of a room air gas monitor with certified reference gases].

PubMed

Krueger, W A; Trick, M; Schroeder, T H; Unertl, K E

2003-12-01

Photo-acoustic infrared spectrometry is considered to be the gold standard for on-line measurement of anesthetic waste gas in room air. For maintenance of the precision of the measurements, the manufacturer recommends calibration of the gas monitor monitor every 3-12 months. We investigated whether the use of reference gases with analysis certificate could serve as a feasible alternative to commercial recalibration. We connected a multi-gas monitor type1302 (Bruel & Kjaer, Naerum, Denmark) to compressed air bottles containing reference gases with analysis certificate. Using a T-piece with a flow-meter, we avoided the entry of room air during the calibration phase. Highly purified nitrogen was used for zero calibration. The reference concentrations for desflurane, enflurane, halothane, isoflurane, and sevoflurane ranged from 41.6-51.1 ml/m(3) (ppm) in synthetic air. Since there is an overlap of the infrared absorption spectra of volatile anesthetics with alcohol used in operating rooms, we performed a cross-compensation with iso-propanol (107.0 ppm). A two-point calibration was performed for N(2)O (96.2 and 979.0 ppm), followed by cross-compensation with CO(2). Nafion tubes were used in order to avoid erroneous measurements due to molecular relaxation phenomena. The deviation of the measurement values ranged initially from 0-2.0% and increased to up to 4.9% after 18 months. For N(2)O, the corresponding values were 4.2% and 2.7%, respectively. Thus, our calibration procedure using certified reference gases yielded precise measurements with low deterioration over 18 months. It seems to be advantageous that the precision can be determined whenever deemed necessary. This allows for an individual decision, when the gas monitor needs to be calibrated again. The costs for reference gases and working time as well as logistic aspects such as storage and expiration dates must be individually balanced against the costs for commercial recalibration.

40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2010 CFR

2010-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals are specified in paragraphs (a)(1) through (a)(3) of this section. (1) The owner or...

Bench-to-bedside review: Molecular pharmacology and clinical use of inert gases in anesthesia and neuroprotection

PubMed Central

2010-01-01

In the past decade there has been a resurgence of interest in the clinical use of inert gases. In the present paper we review the use of inert gases as anesthetics and neuroprotectants, with particular attention to the clinical use of xenon. We discuss recent advances in understanding the molecular pharmacology of xenon and we highlight specific pharmacological targets that may mediate its actions as an anesthetic and neuroprotectant. We summarize recent in vitro and in vivo studies on the actions of helium and the other inert gases, and discuss their potential to be used as neuroprotective agents. PMID:20836899

40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2013 CFR

2013-07-01

... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2012 CFR

2012-07-01

... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2011 CFR

2011-07-01

... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2014 CFR

2014-07-01

... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

Potential gases emissions from the combustion of municipal solid waste by bio-drying.

PubMed

Zhang, Dong-Qing; He, Pin-Jing; Shao, Li-Ming

2009-09-15

One aerobic and two combined hydrolytic-aerobic processes were set up to investigate the influence of bio-drying on the potential emissions of combustion gases and the quantitative relationships of potential emissions with organics degradation. Results showed that the bio-drying would result in the increase of the HCl and SO(2) emissions and potential for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) formation, but the decrease of NO(x) emissions in the combustion. The potential emissions of combustion gases were correlated with organics degradation (correlation coefficient, r=0.67 for HCl, r=0.96 for SO(2), r=0.91 for PCDD/Fs and r=-0.60 for NO(x)). Interestingly, the total emissions of combustion gases based on input waste could be minimized by bio-drying. The bio-drying caused a reduction of NO(x) emissions but a negligible variation of total emissions of HCl and SO(2) as well as the potential for total PCDD/Fs formation. Moreover, the bio-drying could significantly improve the ratio of gas emissions to low heating values. The mixed waste after bio-drying was more favorable for combustion and the combined process with insufficient aeration during the hydrolytic stage was proposed for the bio-drying operation.

European trends in greenhouse gases emissions from integrated solid waste management.

PubMed

Calabrò, Paolo S; Gori, Manuela; Lubello, Claudio

2015-01-01

The European Union (EU) has 28 member states, each with very different characteristics (e.g. surface, population density, per capita gross domestic product, per capita municipal solid waste (MSW) production, MSW composition, MSW management options). In this paper several integrated waste management scenarios representative of the European situation have been generated and analysed in order to evaluate possible trends in the net emission of greenhouse gases and in the required landfill volume. The results demonstrate that an integrated system with a high level of separate collection, efficient energy recovery in waste-to-energy plants and very limited landfill disposal is the most effective according to the indices adopted. Moreover, it is evident that a fully integrated system can make MSW management a carbon sink with a potentiality of up to approximately 40 Mt CO2eq year(-1).

Exploring the Effects on Lipid Bilayer Induced by Noble Gases via Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Chen, Junlang; Chen, Liang; Wang, Yu; Wang, Xiaogang; Zeng, Songwei

2015-11-01

Noble gases seem to have no significant effect on the anesthetic targets due to their simple, spherical shape. However, xenon has strong narcotic efficacy and can be used clinically, while other noble gases cannot. The mechanism remains unclear. Here, we performed molecular dynamics simulations on phospholipid bilayers with four kinds of noble gases to elucidate the difference of their effects on the membrane. Our results showed that the sequence of effects on membrane exerted by noble gases from weak to strong was Ne, Ar, Kr and Xe, the same order as their relative narcotic potencies as well as their lipid/water partition percentages. Compared with the other three kinds of noble gases, more xenon molecules were distributed between the lipid tails and headgroups, resulting in membrane’s lateral expansion and lipid tail disorder. It may contribute to xenon’s strong anesthetic potency. The results are well consistent with the membrane mediated mechanism of general anesthesia.

Financial Implications of Intravenous Anesthetic Drug Wastage in Operation Room

PubMed Central

Kaniyil, Suvarna; Krishnadas, A.; Parathody, Arun Kumar; Ramadas, K. T.

2017-01-01

Background and Objectives: Anesthetic drugs and material wastage are common in operation rooms (ORs). In this era of escalating health-care expenditure, cost reduction strategies are highly relevant. The aim of this study was to assess the amount of daily intravenous anesthetic drug wastage from major ORs and to estimate its financial burden. Any preventive measures to minimize drug wastage are also looked for. Methods: It was a prospective study conducted at the major ORs of a tertiary care hospital after getting the Institutional Research Committee approval. The total amount of all drugs wasted at the end of a surgical day from each major OR was audited for five nonconsecutive weeks. Drug wasted includes the drugs leftover in the syringes unutilized and opened vials/ampoules. The total cost of the wasted drugs and average daily loss were estimated. Results: The drugs wasted in large quantities included propofol, thiopentone sodium, vecuronium, mephentermine, lignocaine, midazolam, atropine, succinylcholine, and atracurium in that order. The total cost of the wasted drugs during the study period was Rs. 59,631.49, and the average daily loss was Rs. 1987.67. The average daily cost of wasted drug was maximum for vecuronium (Rs. 699.93) followed by propofol (Rs. 662.26). Interpretation and Conclusions: Financial implications of anesthetic drug wastage can be significant. Propofol and vecuronium contributed maximum to the financial burden. Suggestions for preventive measures to minimize the wastage include education of staff and residents about the cost of drugs, emphasizing on the judicial use of costly drugs. PMID:28663611

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2012 CFR

2012-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2013 CFR

2013-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2011 CFR

2011-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2014 CFR

2014-07-01

... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

Research of medical gases in Poland

PubMed Central

2013-01-01

Research of medical gases is well established in Poland and has been marked with the foundation of several professional societies. Numerous academic centers including those dealing with hyperbaric and diving medicine conduct studies of medical gases, in vast majority supported with intramural funds. In general, Polish research of medical gases is very much clinical in nature, covering new applications and safety of medical gases in medicine; on the other hand there are several academic centers pursuing preclinical studies, and elaborating basic theories of gas physiology and mathematical modeling of gas exchange. What dominates is research dealing with oxygen and ozone as well as studies of anesthetic gases and their applications. Finally, several research directions involving noble gas, hydrogen and hydrogen sulfide for cell protection, only begin to gain recognition of basic scientists and clinicians. However, further developments require more monetary spending on research and clinical testing as well as formation of new collective bodies for coordinating efforts in this matter. PMID:23916016

Greenhouse gases emissions from waste management practices using Life Cycle Inventory model.

PubMed

Chen, Tsao-Chou; Lin, Cheng-Fang

2008-06-30

When exploring the correlation between municipal solid waste management and green house gas emission, the volume and physical composition of the waste matter must be taken into account. Due to differences in local environments and lifestyles the quantity and composition of waste often vary. This leads to differences in waste treatment methods and causes different volumes of greenhouse gases (GHGs), highlighting the need for local research. In this study the Life Cycle Inventory method was used with global warming indicator GHGs as the variables. By quantifying the data and adopting a region-based approach, this created a model of household MSWM in Taipei City, a metropolitan region in Taiwan. To allow analysis and comparison a compensatory system was then added to expand the system boundary. The results of the analysis indicated that out of all the solid waste management sub-models for a function unit, recycling was the most effective method for reducing GHG emissions while using kitchen food waste as swine feeding resulted in the most GHG emissions. As for the impact of waste collection vehicles on emissions, if the efficiency of transportation could be improved and energy consumption reduced, this will help solid waste management to achieve its goal of reducing GHG emissions.

High temperature abatement of acid gases from waste incineration. Part I: experimental tests in full scale plants.

PubMed

Biganzoli, Laura; Racanella, Gaia; Rigamonti, Lucia; Marras, Roberto; Grosso, Mario

2015-02-01

In recent years, several waste-to-energy plants in Italy have experienced an increase of the concentration of acid gases (HCl, SO2 and HF) in the raw gas. This is likely an indirect effect of the progressive decrease of the amount of treated municipal waste, which is partially replaced by commercial waste. The latter is characterised by a higher variability of its chemical composition because of the different origins, with possible increase of the load of halogen elements such as chlorine (Cl) and fluorine (F), as well as of sulphur (S). A new dolomitic sorbent was then tested in four waste-to-energy plants during standard operation as a pre-cleaning stage, to be directly injected at high temperature in the combustion chamber. For a sorbent injection of about 6 kg per tonne of waste, the decrease of acid gases concentration downstream the boiler was in the range of 7-37% (mean 23%) for HCl, 34-95% (mean 71%) for SO2 and 39-80% (mean 63%) for HF. This pre-abatement of acid gases allowed to decrease the feeding rate of the traditional low temperature sorbent (sodium bicarbonate in all four plants) by about 30%. Furthermore, it was observed by the plant operators that the sorbent helps to keep the boiler surfaces cleaner, with a possible reduction of the fouling phenomena and a consequent increase of the specific energy production. A preliminary quantitative estimate was carried out in one of the four plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

System catalytic neutralization control of combustion engines waste gases in mining technologies

NASA Astrophysics Data System (ADS)

Korshunov, G. I.; Solnitsev, R. I.

2017-10-01

The paper presents the problems solution of the atmospheric air pollution with the exhaust gases of the internal combustion engines, used in mining technologies. Such engines are used in excavators, bulldozers, dump trucks, diesel locomotives in loading and unloading processes and during transportation of minerals. NOx, CO, CH emissions as the waste gases occur during engine operation, the concentration of which must be reduced to the standard limits. The various methods and means are used for the problem solution, one of which is neutralization based on platinum catalysts. A mathematical model of a controlled catalytic neutralization system is proposed. The simulation results confirm the increase in efficiency at start-up and low engine load and the increase in the catalyst lifetime.

[Removal of mixed waste gases by the biotrickling filter].

PubMed

Zhang, Ding-Feng; Fang, Jun-Yi; Ye, Jie-Xu; Qiu, Song-Kai; Qian, Dong-Sheng; Dai, Qi-Zhou; Chen, Dong-Zhi

2013-06-01

A biotrickling filter (BTF) was designed for treating mixed waste gases, which contained hydrogen sulfide (H2S), tetrahydrofuran (THF) and dichloromethane (DCM) at the start-up and steady states. The removal efficiency of H2S and DCM could maintain about 99% and 60%, respectively, and the removal efficiency of DCM was reduced from 90% to 37% with the shortening empty bed retention time (EBRT) form 50 to 20 seconds when the inlet concentrations were 200, 100, 100 mg x m(-3) of H2S, THF, DCM, respectively. In the theoretical study, the biodegradation efficiency of contaminants was H2S > THF > DCM by analyzing the Michaelis-Menten Dynamic model.

Denitrification of combustion gases. [Patent application

DOEpatents

Yang, R.T.

1980-10-09

A method for treating waste combustion gas to remove the nitrogen oxygen gases therefrom is disclosed wherein the waste gas is first contacted with calcium oxide which absorbs and chemically reacts with the nitrogen oxide gases therein at a temperature from about 100/sup 0/ to 430/sup 0/C. The thus reacted calcium oxide (now calcium nitrate) is then heated at a temperature range between about 430/sup 0/ and 900/sup 0/C, resulting in regeneration of the calcium oxide and production of the decomposition gas composed of nitrogen and nitrogen oxide gas. The decomposition gases can be recycled to the calcium oxide contacting step to minimize the amount of nitrogen oxide gases in the final product gas.

Occupational exposure to inhaled anesthetic. Is it a concern for pregnant women?

PubMed

Shuhaiber, S; Koren, G

2000-12-01

Two of my pregnant patients are exposed to inhaled anesthetic on the job. One is an anesthetist, and the other is a veterinarian. They have both expressed concern about this exposure. How should I advise them? Occupational exposure to waste anesthetic gas is not associated with increased risk of major malformations. Risk of spontaneous abortion might be slightly increased, however. This risk can be reduced, if not eliminated, by good gas scavenging systems.

Anesthetic management for carbon dioxide laser surgery of the larynx.

PubMed

Shaker, M H; Konchigeri, H N; Andrews, A H; Holinger, P H

1976-06-01

Fifty-one patients underwent 71 carbon dioxide laser procedures under general anesthesia for various intralaryngeal pathology. Anesthesia was induced with thiopental sodium, followed by succinylcholine to facilitate endotracheal intubation. For maintenance of anesthesia, 70% nitrous oxide was supplemented with halothane, enflurane or small doses of fentanyl. Succinylcholine, d-tubocurare or pancuronium were used to maintain muscular relaxation of jaw, pharyngeal and laryngeal muscles for a smooth lasing procedure. Small diameter (16-22 Fr.), red rubber, cuffed endotracheal tubes provided maximum working space, facilitated the controlled ventilation and reduced the explosion hazard of the anesthetic gases. Safely eyeglasses were used by all the personnel in the operating room against accidental injury to the cornea by the laser beam. Anesthetic management provided excellent operative conditions with maximum safety to the patient and the personnel in the operating room.

Anesthetic action of volatile anesthetics by using Paramecium as a model.

PubMed

Zhou, Miaomiao; Xia, Huimin; Xu, Younian; Xin, Naixing; Liu, Jiao; Zhang, Shihai

2012-06-01

Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as I ( che )) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.

Control of Effluent Gases from Solid Waste Processing Using Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Fisher, John; Cinke, Martin; Wignarajab, Kanapathipillai

2005-01-01

One of the major problems associated with solid waste processing technologies is the release of effluent gases and contaminants that are in gaseous formed from the processes. A number of other gases, in particular NO(x), SO2, NH3, Hydrocarbons (e.g. CH4) do present hazards to the crew in space habitats. Reduction of mass, power, volume and resupply can be achieved by using catalyst impregnated carbon nanotubes as compared to other catalytic systems. The development and characterization of an innovative approach for the control and elimination of gaseous toxins using single walled carbon nanotubes (SWNTs) promise superior performance over conventional approaches. This is due to the ability to direct the selective uptake of gaseous species based on their controllable pore size, high adsorptive capacity and the effectiveness of carbon nanotubes as catalyst supports for gaseous conversion. For example, SWNTs have high adsorptive capacity for NO and the adsorbed NO can be decomposed to N2 and O2 . Experimental results showing the decomposition of NO on metal impregnated carbon nanotubes is presented. Equivalent System Mass (ESM) comparisons are made of the existing TCCS systems with the carbon nanotube technology for removing NO(x). The potential for methane decomposition using carbon nanotubes catalysts is also discussed.

Anesthetic Agents of Plant Origin: A Review of Phytochemicals with Anesthetic Activity.

PubMed

Tsuchiya, Hironori

2017-08-18

The majority of currently used anesthetic agents are derived from or associated with natural products, especially plants, as evidenced by cocaine that was isolated from coca ( Erythroxylum coca , Erythroxylaceae) and became a prototype of modern local anesthetics and by thymol and eugenol contained in thyme ( Thymus vulgaris , Lamiaceae) and clove ( Syzygium aromaticum , Myrtaceae), respectively, both of which are structurally and mechanistically similar to intravenous phenolic anesthetics. This paper reviews different classes of phytochemicals with the anesthetic activity and their characteristic molecular structures that could be lead compounds for anesthetics and anesthesia-related drugs. Phytochemicals in research papers published between 1996 and 2016 were retrieved from the point of view of well-known modes of anesthetic action, that is, the mechanistic interactions with Na⁺ channels, γ-aminobutyric acid type A receptors, N -methyl-d-aspartate receptors and lipid membranes. The searched phytochemicals include terpenoids, alkaloids and flavonoids because they have been frequently reported to possess local anesthetic, general anesthetic, antinociceptive, analgesic or sedative property. Clinical applicability of phytochemicals to local and general anesthesia is discussed by referring to animal in vivo experiments and human pre-clinical trials. This review will give structural suggestions for novel anesthetic agents of plant origin.

40 CFR 258.23 - Explosive gases control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 258.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or... of MSWLFs that dispose of 20 tons of municipal solid waste per day or less, based on an annual...

40 CFR 258.23 - Explosive gases control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 258.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or... of MSWLFs that dispose of 20 tons of municipal solid waste per day or less, based on an annual...

SBRC-Nottingham: sustainable routes to platform chemicals from C1 waste gases

PubMed Central

Burbidge, Alan; Minton, Nigel P.

2016-01-01

Synthetic Biology Research Centre (SBRC)-Nottingham (www.sbrc-nottingham.ac.uk) was one of the first three U.K. university-based SBRCs to be funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and Engineering and Physical Sciences Research Council (EPSRC) as part of the recommendations made in the U.K.'s Synthetic Biology Roadmap. It was established in 2014 and builds on the pioneering work of the Clostridia Research Group (CRG) who have previously developed a range of gene tools for the modification of clostridial genomes. The SBRC is primarily focussed on the conversion of single carbon waste gases into platform chemicals with a particular emphasis on the use of the aerobic chassis Cupriavidus necator. PMID:27284026

Titration calorimetry of anesthetic-protein interaction: negative enthalpy of binding and anesthetic potency.

PubMed

Ueda, I; Yamanaka, M

1997-04-01

Anesthetic potency increases at lower temperatures. In contrast, the transfer enthalpy of volatile anesthetics from water to macromolecules is usually positive. The transfer decreases at lower temperature. It was proposed that a few selective proteins bind volatile anesthetics with negative delta H, and these proteins are involved in signal transduction. There has been no report on direct estimation of binding delta H of anesthetics to proteins. This study used isothermal titration calorimetry to analyze chloroform binding to bovine serum albumin. The calorimetrically measured delta H cal was -10.37 kJ.mol-1. Thus the negative delta H of anesthetic binding is not limited to signal transduction proteins. The binding was saturable following Fermi-Dirac statistics and is characterized by the Langmuir adsorption isotherms, which is interfacial. The high-affinity association constant, K, was 2150 +/- 132 M-1 (KD = 0.47 mM) with the maximum binding number, Bmax = 3.7 +/- 0.2. The low-affinity K was 189 +/- 3.8 M-1 (KD = 5.29 mM), with a Bmax of 13.2 +/- 0.3. Anesthetic potency is a function of the activity of anesthetic molecules, not the concentration. Because the sign of delta H determines the temperature dependence of distribution of anesthetic molecules, it is irrelevant to the temperature dependence of anesthetic potency.

n-Dodecyl β-D-maltoside specifically competes with general anesthetics for anesthetic binding sites.

PubMed

Xu, Longhe; Matsunaga, Felipe; Xi, Jin; Li, Min; Ma, Jingyuan; Liu, Renyu

2014-01-01

We recently demonstrated that the anionic detergent sodium dodecyl sulfate (SDS) specifically interacts with the anesthetic binding site in horse spleen apoferritin, a soluble protein which models anesthetic binding sites in receptors. This raises the possibility of other detergents similarly interacting with and occluding such sites from anesthetics, thereby preventing the proper identification of novel anesthetic binding sites. n-Dodecyl β-D-maltoside (DDM) is a non-ionic detergent commonly used during protein-anesthetic studies because of its mild and non-denaturing properties. In this study, we demonstrate that SDS and DDM occupy anesthetic binding sites in the model proteins human serum albumin (HSA) and horse spleen apoferritin and thereby inhibit the binding of the general anesthetics propofol and isoflurane. DDM specifically interacts with HSA (Kd = 40 μM) with a lower affinity than SDS (Kd = 2 μM). DDM exerts all these effects while not perturbing the native structures of either model protein. Computational calculations corroborated the experimental results by demonstrating that the binding sites for DDM and both anesthetics on the model proteins overlapped. Collectively, our results indicate that DDM and SDS specifically interact with anesthetic binding sites and may thus prevent the identification of novel anesthetic sites. Special precaution should be taken when undertaking and interpreting results from protein-anesthetic investigations utilizing detergents like SDS and DDM.

Comparison of subarachnoid anesthetic effect of emulsified volatile anesthetics in rats.

PubMed

Guo, Jiao; Zhou, Cheng; Liang, Peng; Huang, Han; Li, Fengshan; Chen, Xiangdong; Liu, Jin

2014-01-01

Spinal cord is an important target of volatile anesthetics in particular for the effect of immobility. Intrathecal injection of volatile anesthetics has been found to produce subarachnoid anesthesia. The present study was designed to compare spinal anesthetic effects of emulsified volatile anesthetics, and to investigate the correlation between their spinal effects and general effect of immobility. In this study, halothane, isoflurane, enflurane and sevoflurane were emulsified by 30% Intralipid. These emulsified volatile anesthetics were intravenously and intrathecally injected, respectively. ED50 of general anesthesia and EC50 of spinal anesthesia were determined. The durations of general and spinal anesthesia were recorded. Correlation analysis was applied to evaluate the anesthetic potency of volatile anesthetics between their spinal and general effects. ED50 of general anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.41 ± 0.07, 0.54 ± 0.07, 0.74 ± 0.11 and 0.78 ± 0.08 mmol/kg, respectively, with significant correlation to their inhaled MAC (R(2) = 0.8620, P = 0.047). For intrathecal injection, EC50 of spinal anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.35, 0.27, 0.33 and 0.26 mol/L, respectively, which could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (R(2) = 0.9627, P = 0.013). In conclusion, potency and efficacy of the four emulsified volatile anesthetics in spinal anesthesia were similar and could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (MAC × olive oil/gas partition coefficients).

Local Anesthetic-Induced Neurotoxicity

PubMed Central

Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

2016-01-01

This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor. PMID:26959012

Local Anesthetic-Induced Neurotoxicity.

PubMed

Verlinde, Mark; Hollmann, Markus W; Stevens, Markus F; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

2016-03-04

This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor.

MRI using hyperpolarized noble gases.

PubMed

Kauczor, H; Surkau, R; Roberts, T

1998-01-01

The aim of this study was to review the physical basis of MRI using hyperpolarized noble gases as well as the present status of preclinical and clinical applications. Non-radioactive noble gases with a nuclear spin 1/2 (He-3, Xe-129) can be hyperpolarized by optical pumping. Polarization is transferred from circularly polarized laser light to the noble-gas atoms via alkali-metal vapors (spin exchange) or metastable atoms (metastability exchange). Hyperpolarization results in a non-equilibrium polarization five orders of magnitude higher than the Boltzmann equilibrium compensating for the several 1000 times lower density of noble gases as compared with liquid state hydrogen concentrations in tissue and allows for short imaging times. Hyperpolarization can be stored sufficiently long (3 h to 6 days) to allow for transport and application. Magnetic resonance systems require a broadband radio-frequency system - which is generally available for MR spectroscopy - and dedicated coils. The hyperpolarized gases are administered as inhalative "contrast agents" allowing for imaging of the airways and airspaces. Besides the known anesthetic effect of xenon, no adverse effects are observed in volunteers or patients. Pulse sequences are optimized to effectively use the non-renewable hyperpolarization before it decays or is destroyed, using fast low-flip-angles strategies to allow for dynamic/breath-hold imaging of highly diffusible (He) or soluble (Xe) gases with in vivo T1-times well below 1 min. Since helium is not absorbed in considerable amounts, its application is restricted to the lung. Xe-129 is also under investigation for imaging of white matter disease and functional studies of cerebral perfusion. Magnetic resonance imaging using hyperpolarized gases is emerging as a technical challenge and opportunity for the MR community. Preliminary experience suggests potential for functional imaging of pulmonary ventilation and cerebral perfusion.

Titration calorimetry of anesthetic-protein interaction: negative enthalpy of binding and anesthetic potency.

PubMed Central

Ueda, I; Yamanaka, M

1997-01-01

Anesthetic potency increases at lower temperatures. In contrast, the transfer enthalpy of volatile anesthetics from water to macromolecules is usually positive. The transfer decreases at lower temperature. It was proposed that a few selective proteins bind volatile anesthetics with negative delta H, and these proteins are involved in signal transduction. There has been no report on direct estimation of binding delta H of anesthetics to proteins. This study used isothermal titration calorimetry to analyze chloroform binding to bovine serum albumin. The calorimetrically measured delta H cal was -10.37 kJ.mol-1. Thus the negative delta H of anesthetic binding is not limited to signal transduction proteins. The binding was saturable following Fermi-Dirac statistics and is characterized by the Langmuir adsorption isotherms, which is interfacial. The high-affinity association constant, K, was 2150 +/- 132 M-1 (KD = 0.47 mM) with the maximum binding number, Bmax = 3.7 +/- 0.2. The low-affinity K was 189 +/- 3.8 M-1 (KD = 5.29 mM), with a Bmax of 13.2 +/- 0.3. Anesthetic potency is a function of the activity of anesthetic molecules, not the concentration. Because the sign of delta H determines the temperature dependence of distribution of anesthetic molecules, it is irrelevant to the temperature dependence of anesthetic potency. PMID:9083685

40 CFR 258.23 - Explosive gases control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Explosive gases control. 258.23... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or... facility does not exceed 25 percent of the lower explosive limit for methane in facility structures...

40 CFR 258.23 - Explosive gases control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Explosive gases control. 258.23... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or... facility does not exceed 25 percent of the lower explosive limit for methane in facility structures...

Comparison of subarachnoid anesthetic effect of emulsified volatile anesthetics in rats

PubMed Central

Guo, Jiao; Zhou, Cheng; Liang, Peng; Huang, Han; Li, Fengshan; Chen, Xiangdong; Liu, Jin

2014-01-01

Spinal cord is an important target of volatile anesthetics in particular for the effect of immobility. Intrathecal injection of volatile anesthetics has been found to produce subarachnoid anesthesia. The present study was designed to compare spinal anesthetic effects of emulsified volatile anesthetics, and to investigate the correlation between their spinal effects and general effect of immobility. In this study, halothane, isoflurane, enflurane and sevoflurane were emulsified by 30% Intralipid. These emulsified volatile anesthetics were intravenously and intrathecally injected, respectively. ED50 of general anesthesia and EC50 of spinal anesthesia were determined. The durations of general and spinal anesthesia were recorded. Correlation analysis was applied to evaluate the anesthetic potency of volatile anesthetics between their spinal and general effects. ED50 of general anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.41 ± 0.07, 0.54 ± 0.07, 0.74 ± 0.11 and 0.78 ± 0.08 mmol/kg, respectively, with significant correlation to their inhaled MAC (R2 = 0.8620, P = 0.047). For intrathecal injection, EC50 of spinal anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.35, 0.27, 0.33 and 0.26 mol/L, respectively, which could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (R2 = 0.9627, P = 0.013). In conclusion, potency and efficacy of the four emulsified volatile anesthetics in spinal anesthesia were similar and could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (MAC × olive oil/gas partition coefficients). PMID:25674241

40 CFR 258.23 - Explosive gases control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Explosive gases control. 258.23 Section... MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.23 Explosive gases control. (a) Owners or operators... does not exceed 25 percent of the lower explosive limit for methane in facility structures (excluding...

SBRC-Nottingham: sustainable routes to platform chemicals from C1 waste gases.

PubMed

Burbidge, Alan; Minton, Nigel P

2016-06-15

Synthetic Biology Research Centre (SBRC)-Nottingham (www.sbrc-nottingham.ac.uk) was one of the first three U.K. university-based SBRCs to be funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and Engineering and Physical Sciences Research Council (EPSRC) as part of the recommendations made in the U.K.'s Synthetic Biology Roadmap. It was established in 2014 and builds on the pioneering work of the Clostridia Research Group (CRG) who have previously developed a range of gene tools for the modification of clostridial genomes. The SBRC is primarily focussed on the conversion of single carbon waste gases into platform chemicals with a particular emphasis on the use of the aerobic chassis Cupriavidus necator. © 2016 The Author(s).

Simultaneous Waste Heat and Water Recovery from Power Plant Flue Gases for Advanced Energy Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dexin

This final report presents the results of a two-year technology development project carried out by a team of participants sponsored by the Department of Energy (DOE). The objective of this project is to develop a membrane-based technology to recover both water and low grade heat from power plant flue gases. Part of the recovered high-purity water and energy can be used directly to replace plant boiler makeup water as well as improving its efficiency, and the remaining part of the recovered water can be used for Flue Gas Desulfurization (FGD), cooling tower water makeup or other plant uses. This advancedmore » version Transport Membrane Condenser (TMC) with lower capital and operating costs can be applied to existing plants economically and can maximize waste heat and water recovery from future Advanced Energy System flue gases with CO 2 capture in consideration, which will have higher moisture content that favors the TMC to achieve higher efficiency.« less

Gas Sensor for Volatile Anesthetic Agents Based on Raman Scattering

NASA Astrophysics Data System (ADS)

Schlüter, Sebastian; Popovska-Leipertz, Nadejda; Seeger, Thomas; Leipertz, Alfred

Continuous monitoring of respiratory and anesthetic gases during a surgery is of vital importance for the patient safety. Commonly the gas composition is determined by gas chromatography or a combination of IR-spectroscopy and electrochemical sensors. This study presents a concept for an optical sensor based on spontaneous Raman scattering which offers several advantages compared to established systems. All essential components can be detected simultaneously, no sample preparation is necessary and it provides fast response times. To reach the performance of a commonly used gas monitor signal gain has to be increased e.g. by using a multi pass setup.

Neurometric assessment of intraoperative anesthetic

DOEpatents

Kangas, L.J.; Keller, P.E.

1998-07-07

The present invention is a method and apparatus for collecting EEG data, reducing the EEG data into coefficients, and correlating those coefficients with a depth of unconsciousness or anesthetic depth, and which obtains a bounded first derivative of anesthetic depth to indicate trends. The present invention provides a developed artificial neural network based method capable of continuously analyzing EEG data to discriminate between awake and anesthetized states in an individual and continuously monitoring anesthetic depth trends in real-time. The present invention enables an anesthesiologist to respond immediately to changes in anesthetic depth of the patient during surgery and to administer the correct amount of anesthetic. 7 figs.

Neurometric assessment of intraoperative anesthetic

DOEpatents

Kangas, Lars J.; Keller, Paul E.

1998-01-01

The present invention is a method and apparatus for collecting EEG data, reducing the EEG data into coefficients, and correlating those coefficients with a depth of unconsciousness or anesthetic depth, and which obtains a bounded first derivative of anesthetic depth to indicate trends. The present invention provides a developed artificial neural network based method capable of continuously analyzing EEG data to discriminate between awake and anesthetized states in an individual and continuously monitoring anesthetic depth trends in real-time. The present invention enables an anesthesiologist to respond immediately to changes in anesthetic depth of the patient during surgery and to administer the correct amount of anesthetic.

Neurometric assessment of intraoperative anesthetic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kangas, L.J.; Keller, P.E.

1998-07-07

The present invention is a method and apparatus for collecting EEG data, reducing the EEG data into coefficients, and correlating those coefficients with a depth of unconsciousness or anesthetic depth, and which obtains a bounded first derivative of anesthetic depth to indicate trends. The present invention provides a developed artificial neural network based method capable of continuously analyzing EEG data to discriminate between awake and anesthetized states in an individual and continuously monitoring anesthetic depth trends in real-time. The present invention enables an anesthesiologist to respond immediately to changes in anesthetic depth of the patient during surgery and to administermore » the correct amount of anesthetic. 7 figs.« less

[Humidification and heating of anesthetic gases during pediatric anesthesia using the Cicero Anesthesia Workstation].

PubMed

Strauss, J M; Hausdörfer, J; Hagemann, H; Schröder, D

1992-09-01

A series of 52 infants underwent general or urological surgery; all were ventilated with the CICERO. Two different flows of fresh gas were used. In group I (n = 21) the fresh gas flow was set exactly at the level of the minute volume, representing a half-open, non-rebreathing system. In group II (n = 31) the fresh gas flow was adjusted to 10% of the required minute volume. Temperature and relative humidity of the inspired gas were measured continuously close to the tracheal tube. Anaesthesia was accomplished with 2 vol% isoflurane, 21-30 vol% oxygen in nitrous oxide. The results were compared with those achieved with our time-tested paediatric equipment, a SERVO 900D ventilator with a Fisher-Paykel humidifier (Group III, n = 35). Using a high fresh gas flow, no increase in relative humidity in the inspired gas could be detected. The values varied between 12% and 25% (group I). Reducing the flow of fresh gas as indicated above resulted in an increase in the relative humidity (group II). Over the evaluated period of 2 h, humidity increased slowly from an initial mean value of 20% to a maximum of something over 70%. Using the SERVO 900D ventilator combined with the Fisher-Paykel humidifier, humidity reached a value of greater 90% within 10 min after activation of the heated cascade. Humidity in the inspired gas should exceed 70% to avoid damage to infant airways. This will not be attained until after more than 2 h with unaided breathing systems, by when most operations performed on paediatric patients will already be over. Condensed water may aspirated by small infants. This potentially dangerous situation was only encountered in the CICERO circuit, and not in the system protected by the Fisher-Paykel cascade. Dry gases can result in thickened mucous and in obstruction of a small tracheal tube, which requires emergency reintubation. With artificial airways dry gases damage the ciliated epithelia of the trachea and cause loss of water and body heat. The temperature of

The comparison of fossil carbon fraction and greenhouse gas emissions through an analysis of exhaust gases from urban solid waste incineration facilities.

PubMed

Kim, Seungjin; Kang, Seongmin; Lee, Jeongwoo; Lee, Seehyung; Kim, Ki-Hyun; Jeon, Eui-Chan

2016-10-01

In this study, in order to understand accurate calculation of greenhouse gas emissions of urban solid waste incineration facilities, which are major waste incineration facilities, and problems likely to occur at this time, emissions were calculated by classifying calculation methods into 3 types. For the comparison of calculation methods, the waste characteristics ratio, dry substance content by waste characteristics, carbon content in dry substance, and (12)C content were analyzed; and in particular, CO2 concentration in incineration gases and (12)C content were analyzed together. In this study, 3 types of calculation methods were made through the assay value, and by using each calculation method, emissions of urban solid waste incineration facilities were calculated then compared. As a result of comparison, with Calculation Method A, which used the default value as presented in the IPCC guidelines, greenhouse gas emissions were calculated for the urban solid waste incineration facilities A and B at 244.43 ton CO2/day and 322.09 ton CO2/day, respectively. Hence, it showed a lot of difference from Calculation Methods B and C, which used the assay value of this study. It is determined that this was because the default value as presented in IPCC, as the world average value, could not reflect the characteristics of urban solid waste incineration facilities. Calculation Method B indicated 163.31 ton CO2/day and 230.34 ton CO2/day respectively for the urban solid waste incineration facilities A and B; also, Calculation Method C indicated 151.79 ton CO2/day and 218.99 ton CO2/day, respectively. This study intends to compare greenhouse gas emissions calculated using (12)C content default value provided by the IPCC (Intergovernmental Panel on Climate Change) with greenhouse gas emissions calculated using (12)C content and waste assay value that can reflect the characteristics of the target urban solid waste incineration facilities. Also, the concentration and (12)C content

Selective inhibition of osmotic water flow by general anesthetics to toad urinary bladder.

PubMed Central

Levine, S D; Levine, R D; Worthington, R E; Hays, R M

1976-01-01

Vasopressin increases the permeability of the total urinary bladder, an analogue of the mammalian renal collecting duct, to water and small solutes, especially the amide urea. We have observed that three general anesthetic agents of clinical importance, the gases methoxyflurane and halothane and the ultrashortacting barbiturate methohexital, reversibly inhibit vasopressin-stimulated water flow, but do not depress permeability to urea, or the the lipophilic solute diphenylhydantoin. In contrast to their effects in vasopressin-treated bladders, the anesthetics do not inhibit cyclic AMP-stimulated water flow, consistent with an effect on vasopressin-responsive adenylate cyclase. The selectivity of the anesthetic-induced depression of water flow suggests that separate adenylate cyclases and cyclic AMP pools may exist for control of water and urea permeabilities in to toad bladder. Furthermore, theophylline's usual stimulatory effect on water flow, but not its effect on urea permeability, was entirely abolished in methoxyflurane-treated bladders, suggesting that separate phosphodiesterases that control water and urea permeabilities are present as well. We conclude that the majority of water and urea transport takes place via separate pathways across the rate-limiting luminal membrane of the bladder cell, and that separate vasopressin-responsive cellular pools of cyclic AMP appear to control permeability to water and to urea. PMID:184113

Sterilization of slide sheath anesthetic injection systems placed within sharps containers.

PubMed

Palenik, C J; Burke, F J; Bose, M; Altweis, M L

1997-01-01

The purpose of this study was to evaluate the effect that two steam autoclaves and an unsaturated chemical vapor sterilizer had on killing bacterial endospores present on commercial spore strips or applied to sterile anesthetic injection systems placed within sharps containers. Three types of sterilizers were used: a gravity steam autoclave, a high vacuum steam autoclave and an unsaturated chemical vapor sterilizer. The microbial challenge for the sterilizers were Bacillus stearothermophilus spores present on commercial spore strips or drawn into and applied onto sliding sheath anesthetic injection systems with anesthetic carpules attached. Spore-soiled items were placed into the middle of sharps containers three-quarters-filled with representative clinical waste and sterilized. If, after culturing, sterilization of all test items in a group was not achieved, additional sterilization time was applied. Spore strips were killed within a single cycle of each sterilizer. Spore-soiled injection systems and carpules could not be routinely sterilized in the gravity steam autoclave or unsaturated chemical vapor sterilizers, even after three consecutive sterilization cycles. These items, however, were sterilized by exposure to a single-treatment cycle in a high-vacuum steam autoclave. Results indicate that routine sterilization of spore contaminated anesthetic carpules or injection systems could not be accomplished in a reasonable amount of time using sterilizers commonly found in dental offices.

21 CFR 868.5880 - Anesthetic vaporizer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic vaporizer. 868.5880 Section 868.5880...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5880 Anesthetic vaporizer. (a) Identification. An anesthetic vaporizer is a device used to vaporize liquid anesthetic and deliver a controlled...

21 CFR 868.5880 - Anesthetic vaporizer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthetic vaporizer. 868.5880 Section 868.5880...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5880 Anesthetic vaporizer. (a) Identification. An anesthetic vaporizer is a device used to vaporize liquid anesthetic and deliver a controlled...

21 CFR 868.5880 - Anesthetic vaporizer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthetic vaporizer. 868.5880 Section 868.5880...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5880 Anesthetic vaporizer. (a) Identification. An anesthetic vaporizer is a device used to vaporize liquid anesthetic and deliver a controlled...

21 CFR 868.5880 - Anesthetic vaporizer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthetic vaporizer. 868.5880 Section 868.5880...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5880 Anesthetic vaporizer. (a) Identification. An anesthetic vaporizer is a device used to vaporize liquid anesthetic and deliver a controlled...

21 CFR 868.5880 - Anesthetic vaporizer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthetic vaporizer. 868.5880 Section 868.5880...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5880 Anesthetic vaporizer. (a) Identification. An anesthetic vaporizer is a device used to vaporize liquid anesthetic and deliver a controlled...

21 CFR 872.6100 - Anesthetic warmer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to be...

21 CFR 872.6100 - Anesthetic warmer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to be...

21 CFR 872.6100 - Anesthetic warmer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to be...

21 CFR 872.6100 - Anesthetic warmer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to be...

21 CFR 872.6100 - Anesthetic warmer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to be...

Using STELLA System Dynamic Model to Analyze Greenhouse Gases' Emission From Solid Waste Management in Taiwan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horng, Jao-Jia; Lee, R.F.; Liao, K.Y.

2004-03-31

Using a system dynamic model (SDM), such as STELLA, to analyze the waste management policy is a new trial for Taiwan's research communities. We have developed an easy and relatively accurate model for analyzing the greenhouse gases emission for the wastes from animal farming and municipalities. With the local research data of the past decade, we extract the most prominent factors and assemble the SDM. The results and scenarios were compared with the national inventory. By comparing to the past data, we found these models reasonably represent the situation in Taiwan. However, SDM can program many scenarios and produce amore » lot of prediction data. With the development of many program control tools on STELLA, we believe the models could be further used by researchers or policy-makers to find the needed research topics, to set the future scenarios and to determine the management tools.« less

A comparison of a refrigerant and a topical anesthetic gel as preinjection anesthetics: a clinical evaluation.

PubMed

Kosaraju, Amar; Vandewalle, Kraig S

2009-01-01

The authors used a split-mouth design to determine the effectiveness of a refrigerant compared with that of a topical anesthetic gel in reducing the pain experienced during a posterior palatal anesthetic injection. Sixteen participants received a five-second application of a refrigerant (1,1,1,3,3-pentafluoropropane/1,1,1,2-tetrafluoroethane) and a two-minute application of a topical anesthetic gel (20 percent benzocaine gel) in the posterior palatal area before an injection of a local anesthetic solution was administered with a 30-gauge needle. Participants rated the pain they experienced after each injection by using a 100-millimeter visual analog scale (VAS) with endpoints of "no pain" and "worst possible pain." The authors calculated VAS scores by measuring the distance in millimeters from the no pain end of the scale. They analyzed data with a paired t test (alpha = .05). The group receiving the refrigerant had a mean VAS score of 17.7 +/- 15.3 mm, and the group receiving the topical anesthetic gel had a VAS score of 26.2 +/- 18.0 mm. The use of the refrigerant compared with the use of topical anesthetic gel significantly reduced the pain experienced during administration of local anesthetic injections (P = .02). The use of a refrigerant as a preinjection anesthetic was more effective compared with the use of a topical anesthetic gel in reducing the pain experienced by participants who received a posterior palatal injection. The potential benefits of using a refrigerant rather than a topical anesthetic gel are pain reduction, decreased application time, ease of application and avoidance of displeasing taste.

Preventable drug waste among anesthesia providers: opportunities for efficiency.

PubMed

Atcheson, Carrie Leigh Hamby; Spivack, John; Williams, Robert; Bryson, Ethan O

2016-05-01

Health care service bundling experiments at the state and regional levels have showed reduced costs by providing a single lump-sum reimbursement for anesthesia services, surgery, and postoperative care. Potential for cost savings related to the provision of anesthesia care has the potential to significantly impact sustainability. This study defines and quantifies routine and preventable anesthetic drug waste and the patient, procedure, and anesthesia provider characteristics associated with increased waste. Over a 12-month period, the type and quantity of clean drugs prepared by the anesthesia team for the first case of the day were recorded. The amount of each drug administered was obtained from the computerized anesthesia record, and data were analyzed to determine the incidence and cost of routine and preventable drug waste. The monthly and yearly cost of preventable waste, including the cost of pharmacy tech labor and materials where applicable, was estimated based on surgical case volume at the study institution. All analyses were performed using SAS software v9.2. Anesthetic drugs prepared for 543 separate surgical cases were observed. Less than 20% of cases generated routine waste. Preventable waste was generated most frequently for ephedrine (59.5% of cases), succinylcholine (33.7%), and lidocaine (25.1%), and least frequently for ondansetron (1.3%), phenylephrine (2.6%), and dexamethasone (2.8%). The estimated yearly cost of preventable anesthetic drug waste was $185,250. Significant potential savings with little impact on clinically significant availability may be achieved through the use of prefilled syringes for some commonly used anesthetic drugs. An intelligently implemented switch to prefilled syringes for select drugs is a potential cost saving measure, but savings might be diminished by disposal of prefilled syringes when they expire, hidden costs in the hospital pharmacy, and inability to supply some medications in prefilled syringes due to

Impact of oxy-fuel combustion gases on mercury retention in activated carbons from a macroalgae waste: effect of water.

PubMed

Lopez-Anton, M A; Ferrera-Lorenzo, N; Fuente, E; Díaz-Somoano, M; Suarez-Ruíz, I; Martínez-Tarazona, M R; Ruiz, B

2015-04-01

The aim of this study is to understand the different sorption behaviors of mercury species on activated carbons in the oxy-fuel combustion of coal and the effect of high quantities of water vapor on the retention process. The work evaluates the interactions between the mercury species and a series of activated carbons prepared from a macroalgae waste (algae meal) from the agar-agar industry in oxy-combustion atmospheres, focussing on the role that the high concentration of water in the flue gases plays in mercury retention. Two novel aspects are considered in this work (i) the impact of oxy-combustion gases on the retention of mercury by activated carbons and (ii) the performance of activated carbons prepared from biomass algae wastes for this application. The results obtained at laboratory scale indicate that the effect of the chemical and textural characteristics of the activated carbons on mercury capture is not as important as that of reactive gases, such as the SOx and water vapor present in the flue gas. Mercury retention was found to be much lower in the oxy-combustion atmosphere than in the O2+N2 (12.6% O2) atmosphere. However, the oxidation of elemental mercury (Hg0) to form oxidized mercury (Hg2+) amounted to 60%, resulting in an enhancement of mercury retention in the flue gas desulfurization units and a reduction in the amalgamation of Hg0 in the CO2 compression unit. This result is of considerable importance for the development of technologies based on activated carbon sorbents for mercury control in oxy-combustion processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of sulfur and nitrogen containing pollutants from discharge gases

DOEpatents

Joubert, James I.

1986-01-01

Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

Local Anesthetic Microcapsules.

DTIC Science & Technology

1981-04-15

III Chemical Structure of Local Anesthetics 12 Table IV Processing Summary of Lidocaine Microencapsulation 15 Table V Lidocaine Microcapsule Size...Distribution 17 Table VI Processing Summary of Etidocaine Microencapsulation 18 Table VII Etidocaine Microcapsule Size Distribution 19 Table VIII Lidocaine...REPORT I PERIOD COVERED Annual Local Anesthetic Microcapsules 1 July 1980-30 March 1981 6. PERFORMING ORG. REPORT NUMBER 2106-1 7. AUTHOR() S

Volatile anesthetics affect nutrient availability in yeast.

PubMed Central

Palmer, Laura K; Wolfe, Darren; Keeley, Jessica L; Keil, Ralph L

2002-01-01

Volatile anesthetics affect all cells and tissues tested, but their mechanisms and sites of action remain unknown. To gain insight into the cellular activities of anesthetics, we have isolated genes that, when overexpressed, render Saccharomyces cerevisiae resistant to the volatile anesthetic isoflurane. One of these genes, WAK3/TAT1, encodes a permease that transports amino acids including leucine and tryptophan, for which our wild-type strain is auxotrophic. This suggests that availability of amino acids may play a key role in anesthetic response. Multiple lines of evidence support this proposal: (i) Deletion or overexpression of permeases that transport leucine and/or tryptophan alters anesthetic response; (ii) prototrophic strains are anesthetic resistant; (iii) altered concentrations of leucine and tryptophan in the medium affect anesthetic response; and (iv) uptake of leucine and tryptophan is inhibited during anesthetic exposure. Not all amino acids are critical for this response since we find that overexpression of the lysine permease does not affect anesthetic sensitivity. These findings are consistent with models in which anesthetics have a physiologically important effect on availability of specific amino acids by altering function of their permeases. In addition, we show that there is a relationship between nutrient availability and ubiquitin metabolism in this response. PMID:12072454

The environmental impact of the Glostavent® anesthetic machine.

PubMed

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

Lipid Emulsion for Local Anesthetic Systemic Toxicity

PubMed Central

Ciechanowicz, Sarah; Patil, Vinod

2012-01-01

The accidental overdose of local anesthetics may prove fatal. The commonly used amide local anesthetics have varying adverse effects on the myocardium, and beyond a certain dose all are capable of causing death. Local anesthetics are the most frequently used drugs amongst anesthetists and although uncommon, local anaesthetic systemic toxicity accounts for a high proportion of mortality, with local anaesthetic-induced cardiac arrest particularly resistant to standard resuscitation methods. Over the last decade, there has been convincing evidence of intravenous lipid emulsions as a rescue in local anesthetic-cardiotoxicity, and anesthetic organisations, over the globe have developed guidelines on the use of this drug. Despite this, awareness amongst practitioners appears to be lacking. All who use local anesthetics in their practice should have an appreciation of patients at high risk of toxicity, early symptoms and signs of toxicity, preventative measures when using local anesthetics, and the initial management of systemic toxicity with intravenous lipid emulsion. In this paper we intend to discuss the pharmacology and pathophysiology of local anesthetics and toxicity, and the rationale for lipid emulsion therapy. PMID:21969824

Biofiltration of composting gases using different municipal solid waste-pruning residue composts: monitoring by using an electronic nose.

PubMed

López, R; Cabeza, I O; Giráldez, I; Díaz, M J

2011-09-01

The concentration of volatile organic compounds (VOCs) during the composting of kitchen waste and pruning residues, and the abatement of VOCs by different compost biofilters was studied. VOCs removal efficiencies greater than 90% were obtained using composts of municipal solid waste (MSW) or MSW-pruning residue as biofilter material. An electronic nose identified qualitative differences among the biofilter output gases at very low concentrations of VOCs. These differences were related to compost constituents, compost particle size (2-7 or 7-20mm), and a combination of both factors. The total concentration of VOCs determined by a photoionization analyser and inferred from electronic nose data sets were correlated over an ample range of concentrations of VOCs, showing that these techniques could be specially adapted for the monitoring of these processes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Waste management system

NASA Technical Reports Server (NTRS)

Sauer, R. L.; Jorgensen, G. K.

1975-01-01

The function of the waste management system was to control the disposition of solid and liquid wastes and waste stowage gases. The waste management system consisting of a urine subsystem and a fecal subsystem is described in detail and its overall performance is evaluated. Recommendations for improvement are given.

Drug interactions: volatile anesthetics and opioids.

PubMed

Glass, P S; Gan, T J; Howell, S; Ginsberg, B

1997-09-01

Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

Genotoxicity of Anesthetics Evaluated In Vivo (Animals)

PubMed Central

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

Corneal anesthetic abuse and Candida keratitis.

PubMed

Chern, K C; Meisler, D M; Wilhelmus, K R; Jones, D B; Stern, G A; Lowder, C Y

1996-01-01

Topical corneal anesthetic abuse is a self-inflicted injury, causing profound corneal morbidity. Superimposed infection is an important complicating factor. The authors report four patients with confirmed topical anesthetic abuse of the cornea, in whom Candida keratitis developed. A retrospective review of the medical records of four patients with confirmed topical corneal anesthetic abuse and fungal keratitis. A 21-year-old woman, two 28-year-old women, and a 35-year-old man were included in the study. All these patients sustained a corneal injury, prompting the chronic use of topical anesthetics (0.5% proparacaine hydrochloride in 3 patients, and 0.5% tetracaine hydrochloride and 0.4% benoxinate hydrochloride in the other). Corneal findings included epithelial defects in all patients, focal infiltrate in one patient, and ring-shaped stromal infiltrate in three patients. Topical anesthetic was discontinued, all patients initially were treated empirically with antibacterial agents, and three patients received topical corticosteroids. Subsequent corneal cultures grew Candida spp, Candida albicans specifically in three patients, and local and systemic antifungal therapy was started. Corneas in two patients re-epithelialized; a conjunctival flap was performed on another patient with a descemetocele; and the remaining patient was lost to follow-up, although repeat fungal cultures yielded no growth. Corneal superinfection with Candida may occur during topical anesthetic abuse. Therapy includes discontinuation of the anesthetic and institution of antifungal therapy.

Online elemental analysis of process gases with ICP-OES: A case study on waste wood combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wellinger, Marco, E-mail: marco.wellinger@gmail.com; Ecole Polytechnique Federale de Lausanne; Wochele, Joerg

2012-10-15

Highlights: Black-Right-Pointing-Pointer Simultaneous measurements of 23 elements in process gases of a waste wood combustor. Black-Right-Pointing-Pointer Mobile ICP spectrometer allows measurements of high quality at industrial plants. Black-Right-Pointing-Pointer Continuous online measurements with high temporal resolution. Black-Right-Pointing-Pointer Linear correlations among element concentrations in the raw flue gas were detected. Black-Right-Pointing-Pointer Novel sampling and calibration methods for ICP-OES analysis of process gases. - Abstract: A mobile sampling and measurement system for the analysis of gaseous and liquid samples in the field was developed. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is built into a van, was used as detector. Themore » analytical system was calibrated with liquid and/or gaseous standards. It was shown that identical mass flows of either gaseous or liquid standards resulted in identical ICP-OES signal intensities. In a field measurement campaign trace and minor elements in the raw flue gas of a waste wood combustor were monitored. Sampling was performed with a highly transport efficient liquid quench system, which allowed to observe temporal variations in the elemental process gas composition. After a change in feedstock an immediate change of the element concentrations in the flue gas was detected. A comparison of the average element concentrations during the combustion of the two feedstocks showed a high reproducibility for matrix elements that are expected to be present in similar concentrations. On the other hand elements that showed strong differences in their concentration in the feedstock were also represented by a higher concentration in the flue gas. Following the temporal variations of different elements revealed strong correlations between a number of elements, such as chlorine with sodium, potassium and zinc, as well as arsenic with lead, and calcium with strontium.« less

Neurogenesis and Developmental Anesthetic Neurotoxicity

PubMed Central

Kang, Eunchai; Berg, Daniel A.; Furmanski, Orion; Jackson, William M.; Ryu, Yun Kyoung; Gray, Christy D.; Mintz, C. David

2017-01-01

The mechanism by which anesthetics might act on the developing brain in order to cause long term deficits remains incompletely understood. The hippocampus has been identified as a structure that is likely to be involved, as rodent models show numerous deficits in behavioral tasks of learning that are hippocampal-dependent. The hippocampus is an unusual structure in that it is the site of large amounts of neurogenesis postnatally, particularly in the first year of life in humans, and these newly generated neurons are critical to the function of this structure. Intriguingly, neurogenesis is a major developmental event that occurs during postulated windows of vulnerability to developmental anesthetic neurotoxicity across the different species in which it has been studied. In this review, we examine the evidence for anesthetic effects on neurogenesis in the early postnatal period and ask whether neurogenesis should be studied further as a putative mechanism of injury. Multiple anesthetics are considered, and both in vivo and in vitro work is presented. While there is abundant evidence that anesthetics act to suppress neurogenesis at several different phases, evidence of a causal link between these effects and any change in learning behavior remains elusive. PMID:27751818

Electrochemical incineration of wastes

NASA Technical Reports Server (NTRS)

Kaba, L.; Hitchens, G. D.; Bockris, J. OM.

1989-01-01

The disposal of domestic organic waste in its raw state is a matter of increasing public concern. Earlier, it was regarded as permissible to reject wastes into the apparently infinite sink of the sea but, during the last 20 years, it has become clear that this is environmentally unacceptable. On the other hand, sewage farms and drainage systems for cities and for new housing developments are cumbersome and expensive to build and operate. New technology whereby waste is converted to acceptable chemicals and pollution-free gases at site is desirable. The problems posed by wastes are particularly demanding in space vehicles where it is desirable to utilize treatments that will convert wastes into chemicals that can be recycled. In this situation, the combustion of waste is undesirable due to the inevitable presence of oxides of nitrogen and carbon monoxide in the effluent gases. Here, in particular, electrochemical techniques offer several advantages including the low temperatures which may be used and the absence of any NO and CO in the evolved gases. Work done in this area was restricted to technological papers, and the present report is an attempt to give a more fundamental basis to the early stages of a potentially valuable technology.

Effects of Anesthetics on Brain Circuit Formation

PubMed Central

Wagner, Meredith; Ryu, Yun Kyoung; Smith, Sarah C.; Mintz, C. David

2014-01-01

The results of several retrospective clinical studies suggest that exposure to anesthetic agents early in life is correlated with subsequent learning and behavioral disorders. While ongoing prospective clinical trials may help to clarify this association, they remain confounded by numerous factors. Thus, some of the most compelling data supporting the hypothesis that a relatively short anesthetic exposure can lead to a long-lasting change in brain function are derived from animal models. The mechanism by which such changes could occur remains incompletely understood. Early studies identified anesthetic-induced neuronal apoptosis as a possible mechanism of injury, and more recent work suggests that anesthetics may interfere with several critical processes in brain development. The function of the mature brain requires the presence of circuits, established during development, that perform the computations underlying learning and cognition. In this review we examine the mechanisms by which anesthetics could disrupt brain circuit formation, including effects on neuronal survival and neurogenesis, neurite growth and guidance, formation of synapses, and function of supporting cells. There is evidence that anesthetics can disrupt aspects of all of these processes, and further research is required to elucidate which are most relevant to pediatric anesthetic neurotoxicity. PMID:25144504

Neurogenesis and developmental anesthetic neurotoxicity.

PubMed

Kang, Eunchai; Berg, Daniel A; Furmanski, Orion; Jackson, William M; Ryu, Yun Kyoung; Gray, Christy D; Mintz, C David

The mechanism by which anesthetics might act on the developing brain in order to cause long term deficits remains incompletely understood. The hippocampus has been identified as a structure that is likely to be involved, as rodent models show numerous deficits in behavioral tasks of learning that are hippocampal-dependent. The hippocampus is an unusual structure in that it is the site of large amounts of neurogenesis postnatally, particularly in the first year of life in humans, and these newly generated neurons are critical to the function of this structure. Intriguingly, neurogenesis is a major developmental event that occurs during postulated windows of vulnerability to developmental anesthetic neurotoxicity across the different species in which it has been studied. In this review, we examine the evidence for anesthetic effects on neurogenesis in the early postnatal period and ask whether neurogenesis should be studied further as a putative mechanism of injury. Multiple anesthetics are considered, and both in vivo and in vitro work is presented. While there is abundant evidence that anesthetics act to suppress neurogenesis at several different phases, evidence of a causal link between these effects and any change in learning behavior remains elusive. Copyright © 2016. Published by Elsevier Inc.

Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, S.A.; Pederson, L.R.; Ryan, J.L.

1992-08-01

Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed.more » The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust.« less

Anesthetic drugs and onset of malignant hyperthermia.

PubMed

Visoiu, Mihaela; Young, Michael C; Wieland, Keith; Brandom, Barbara W

2014-02-01

The time between the beginning of anesthetic administration and recognition of the first sign of malignant hyperthermia (MH) (MH onset time) could differ among anesthetic drugs. We examined the time of the first signs of suspected MH, anesthetic drugs administered, subject age, and year of event in Adverse Metabolic/Musculoskeletal Reaction to Anesthesia reports in the North American Malignant Hyperthermia Registry. Inclusion criteria were judgment by the reporting clinician that the event was possible or fulminant MH, documentation of the time when anesthetic administration began, and the time when the first MH sign was noted. Descriptive statistics, Kruskal-Wallis analysis, and nonparametric correlation were used to assess the difference in MH onset times under different conditions. Four hundred seventy-seven cases met inclusion criteria; 58.5% were possible MH and 41.5% fulminant MH. Inhaled anesthetic and succinylcholine were given in 53.9% of cases, inhaled anesthetic only in 41.7%, and succinylcholine without inhaled anesthetics in 2.9%. No causative anesthetic drugs were reported in 7 MH cases. In 394 patients exposed to only 1 of the 4 inhaled anesthetics, without regard for subject age, MH onset time was shorter in the presence of halothane than any of the other anesthetics and shorter after succinylcholine in all anesthetics. If succinylcholine was not given, MH onset was shorter during sevoflurane anesthesia than during desflurane or isoflurane. In 322 cases, 1 rather than multiple first signs of MH were reported with masseter spasm as the earliest MH sign. In 339 cases in which masseter spasm was not reported, there was no difference in MH onset time with or without succinylcholine. In 146 cases in which masseter spasm was not reported and succinylcholine was not given, MH onset was shorter during halothane anesthesia, than during exposure to desflurane, or isoflurane. MH onset time during sevoflurane was shorter than during desflurane or isoflurane. MH

U.S. Space Station Freedom waste fluid disposal system with consideration of hydrazine waste gas injection thrusters

NASA Technical Reports Server (NTRS)

Winters, Brian A.

1990-01-01

The results are reported of a study of various methods for propulsively disposing of waste gases. The options considered include hydrazine waste gas injection, resistojets, and eutectic salt phase change heat beds. An overview is given of the waste gas disposal system and how hydrozine waste gas injector thruster is implemented within it. Thruster performance for various gases are given and comparisons with currently available thruster models are made. The impact of disposal on station propellant requirements and electrical power usage are addressed. Contamination effects, reliability and maintainability assessments, safety issues, and operational scenarios of the waste gas thruster and disposal system are considered.

21 CFR 868.5550 - Anesthetic gas mask.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

21 CFR 868.5550 - Anesthetic gas mask.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

46 CFR 111.105-37 - Flammable anesthetics.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Flammable anesthetics. 111.105-37 Section 111.105-37...-GENERAL REQUIREMENTS Hazardous Locations § 111.105-37 Flammable anesthetics. Each electric installation where a flammable anesthetic is used or stored must meet NFPA 99 (incorporated by reference, see 46 CFR...

46 CFR 111.105-37 - Flammable anesthetics.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Flammable anesthetics. 111.105-37 Section 111.105-37...-GENERAL REQUIREMENTS Hazardous Locations § 111.105-37 Flammable anesthetics. Each electric installation where a flammable anesthetic is used or stored must meet NFPA 99 (incorporated by reference, see 46 CFR...

21 CFR 868.5550 - Anesthetic gas mask.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

46 CFR 111.105-37 - Flammable anesthetics.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Flammable anesthetics. 111.105-37 Section 111.105-37...-GENERAL REQUIREMENTS Hazardous Locations § 111.105-37 Flammable anesthetics. Each electric installation where a flammable anesthetic is used or stored must meet NFPA 99 (incorporated by reference, see 46 CFR...

21 CFR 868.5550 - Anesthetic gas mask.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

21 CFR 868.5550 - Anesthetic gas mask.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

46 CFR 111.105-37 - Flammable anesthetics.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Flammable anesthetics. 111.105-37 Section 111.105-37...-GENERAL REQUIREMENTS Hazardous Locations § 111.105-37 Flammable anesthetics. Each electric installation where a flammable anesthetic is used or stored must meet NFPA 99 (incorporated by reference, see 46 CFR...

46 CFR 111.105-37 - Flammable anesthetics.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Flammable anesthetics. 111.105-37 Section 111.105-37...-GENERAL REQUIREMENTS Hazardous Locations § 111.105-37 Flammable anesthetics. Each electric installation where a flammable anesthetic is used or stored must meet NFPA 99 (incorporated by reference, see 46 CFR...

Anesthetic Concerns of Space Flight

NASA Technical Reports Server (NTRS)

Norfleet, William T.

1999-01-01

Anesthesiologists are acutely aware of the fact that, although a given surgical procedure may be relatively simple, the required anesthetic care is, in certain cases, extremely complex. This principle is particularly evident when one ponders the difficulties involved in providing even basic anesthetic care in microgravity. In this issue some of these difficulties through the evaluation of airway management techniques during water immersion are confronted, a simulation of the gravito-inertial conditions of space flight. As prelude for this paper, I would like to outline some of the challenges to be overcome before surgical, anesthetic, and critical care can be delivered beyond our home planet.

Anesthetic agent-specific effects on synaptic inhibition.

PubMed

MacIver, M Bruce

2014-09-01

Anesthetics enhance γ-aminobutyric acid (GABA)-mediated inhibition in the central nervous system. Different agents have been shown to act on tonic versus synaptic GABA receptors to different degrees, but it remains unknown whether different forms of synaptic inhibition are also differentially engaged. With this in mind, we tested the hypothesis that different types of GABA-mediated synapses exhibit different anesthetic sensitivities. The present study compared effects produced by isoflurane, halothane, pentobarbital, thiopental, and propofol on paired-pulse GABAA receptor-mediated synaptic inhibition. Effects on glutamate-mediated facilitation were also studied. Synaptic responses were measured in rat hippocampal brain slices. Orthodromic paired-pulse stimulation was used to assess anesthetic effects on either glutamate-mediated excitatory inputs or GABA-mediated inhibitory inputs to CA1 neurons. Antidromic stimulation was used to assess anesthetic effects on CA1 background excitability. Agents were studied at equieffective concentrations for population spike depression to compare their relative degree of effect on synaptic inhibition. Differing degrees of anesthetic effect on paired-pulse facilitation at excitatory glutamate synapses were evident, and blocking GABA inhibition revealed a previously unseen presynaptic action for pentobarbital. Although all 5 anesthetics depressed synaptically evoked excitation of CA1 neurons, the involvement of enhanced GABA-mediated inhibition differed considerably among agents. Single-pulse inhibition was enhanced by propofol, thiopental, and pentobarbital, but only marginally by halothane and isoflurane. In contrast, isoflurane enhanced paired-pulse inhibition strongly, as did thiopental, but propofol, pentobarbital, and halothane were less effective. These observations support the idea that different GABA synapses use receptors with differing subunit compositions and that anesthetics exhibit differing degrees of selectivity for

Ischemia-Reperfusion Injury and Volatile Anesthetics

PubMed Central

Erturk, Engin

2014-01-01

Ischemia-reperfusion injury (IRI) is induced as a result of reentry of the blood and oxygen to ischemic tissue. Antioxidant and some other drugs have protective effect on IRI. In many surgeries and clinical conditions IRI is counteract inevitable. Some anesthetic agents may have a protective role in this procedure. It is known that inhalational anesthetics possess protective effects against IRI. In this review the mechanism of preventive effects of volatile anesthetics and different ischemia-reperfusion models are discussed. PMID:24524079

Treatment of local-anesthetic toxicity with lipid emulsion therapy.

PubMed

Burch, Melissa S; McAllister, Russell K; Meyer, Tricia A

2011-01-15

The use of lipid emulsion to treat local-anesthetic toxicity is discussed. Systemic toxicity from local anesthetics is a rare but potentially fatal complication of regional anesthesia. There is increasing evidence that lipid emulsion may be an effective treatment to reverse the cardiac and neurologic effects of local-anesthetic toxicity. A literature search identified seven case reports of local-anesthetic toxicity in which lipid emulsion was used. Lipid emulsion was found to be successful in the treatment of local-anesthetic toxicity associated with various regional anesthetic techniques and multiple local anesthetics. The majority of patients in the case reports reviewed were unresponsive to initial management of local-anesthetic toxicity with standard resuscitative measures, but all recovered completely after receiving lipid emulsion therapy. The initial dose of lipid emulsion administered varied among the case reports, as well as whether a lipid emulsion infusion was started and at what point during resuscitation. Based on the case reports reviewed, an initial bolus dose of 1.5 mL/kg followed by an infusion of 10 mL/min as soon as local-anesthetic toxicity is suspected seems most beneficial. The pharmacokinetics of lipid emulsion therapy in the treatment of local-anesthetic toxicity has not been fully elucidated but likely involves increasing metabolism, distribution, or partitioning of the local anesthetic away from receptors into lipid within tissues. Lipid emulsion has been reported useful in the treatment of systemic toxicity caused by local anesthetics. The mechanism of effect is unclear, and evidence for the benefit of lipid therapy in humans is from case reports only.

[EFFECTS OF CANNABIS EXTRACT PREMEDICATION ON ANESTHETIC DEPTH].

PubMed

Ibera, Carlos; Shalom, Ben; Saifi, Fayez; Shruder, Joshua; Davidson, Elyad

2018-03-01

Cannabis is the most widely used illicit drug in the world, used by approximately 2.7-4.9% of the world's population, and 7.6-10.2% of Israel's adults. During the past few years, legal systems around the world have enacted large scale adoption of the legalization of both medical and recreational cannabis. Anesthetists should therefore be prepared to treat patients who used cannabis and are undergoing elective or emergency operations. However, the interactions between cannabinoids and general anesthetic agents and the possible implications for patient care are not yet fully understood. The study aimed to examine how preoperative use of cannabis affects the anesthesia process, and whether this use requires special attention by the anesthesiologists during surgery. Hence, we examined the effect of preoperative administration of cannabis extract Sativex (nabiximols) on obtained BIS value relative to the concentration of anesthetic gases. This study is a double-blind randomized controlled trial. Twenty-seven patients undergoing elective orthopedic surgery under general anesthesia were randomly allocated to one of the following regimes: high dose cannabis (6), low dose cannabis (8), active placebo (6) and placebo (7). The study drugs were administered as premedication 20 minutes before induction of general anesthesia in a double-blind fashion. Cannabis was administered in the form of nabiximols (Sativex®), which is a highly-standardized extract of cannabis plants containing known drug dosages. During the surgery, hemodynamic parameters were monitored, and the anesthesia depth was measured using a BIS monitor, which is based on brain activity analysis. We found a significant effect of treatment groups on bispectral index (BIS) after controlling for minimum alveolar concentration (MAC). The average BIS values, as measured during steady state anesthesia, were significantly higher in the high dose cannabis treatment group. This study provides the first evidence that

A Unitary Anesthetic Binding Site at High Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vedula, L. Sangeetha; Brannigan, Grace; Economou, Nicoleta J.

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 thatmore » 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.« less

A Unitary Anesthetic Binding Site at High Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

L Vedula; G Brannigan; N Economou

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 thatmore » 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.« less

A Unitary Anesthetic-Binding Site at High Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vedula, L.; Brannigan, G; Economou, N

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 apoferritinmore » 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.« less

Development of An Assessment Test for An Anesthetic Machine.

PubMed

Tiviraj, Supinya; Yokubol, Bencharatana; Amornyotin, Somchai

2016-05-01

The study is aimed to develop and assess the quality of an evaluation form used to evaluate the nurse anesthetic trainees' skills in undertaking a pre-use check of an anesthetic machine. An evaluation form comprising 25 items was developed, informed by the guidelines published by national anesthesiologist societies and refined to reflect the anesthetic machine used in our institution. The item-checking included the cylinder supplies and medical gas pipelines, vaporizer back bar, ventilator anesthetic breathing system, scavenging system and emergency back-up equipment. The authors sought the opinions of five experienced anesthetic trainers to judge the validity of the content. The authors measured its inter-rater reliability when used by two achievement scores evaluating the performance of 36 nurse anesthetic trainees undertaking 15-minute anesthetic machine checks and test-retest the reliability correlation scores between the two performances in the seven days interval. The five experienced anesthesiologists agreed that the evaluation form accurately reflected the objectives of anesthetic machine checking, equating to an index of congruency of 1.00. The inter-rater reliability of the independent assessors scoring was 0.977 (p = 0.01) and the test-retest reliability was 0.883 (p = 0.01). An evaluation form proved to be a reliable and effective tool for assessing the anesthetic nurse trainees' checking of an anesthetic machine before the use. This evaluation form was brief clear and practical to use, and should help to improve anesthetic nurse education and the patient safety.

The use of the mandibular infiltration anesthetic technique in adults.

PubMed

Meechan, John G

2011-09-01

The author describes the use of the infiltration anesthetic technique to anesthetize mandibular teeth in adults and explores its mechanism of action. The author reviewed articles describing randomized controlled trials of the mandibular infiltration anesthetic technique in healthy participants. The author found that using the mandibular infiltration anesthetic technique can produce anesthesia in adult mandibular teeth. The success was dose dependent and the choice of anesthetic solution was significant; 4 percent articaine with 1:100,000 epinephrine was more effective than 2 percent lidocaine with 1:100,000 epinephrine. Combining buccal and lingual infiltrations increased success in the mandibular incisor region. The success of the mechanism of infiltration of anesthetic at the mandibular first molar appeared to depend on the mental foramen. The mandibular infiltration anesthetic technique is an effective method of anesthetizing mandibular incisors. Four percent articaine with epinephrine appears to be the preferred solution. The choice of anesthetic solution is important when using the infiltration anesthetic technique in the adult mandible.

Dose-response effects of corneal anesthetics.

PubMed

Polse, K A; Keener, R J; Jauregui, M J

1978-01-01

With double-masking procedures, the dose-response curves for 0.1, 0.2, and 0.4% benoxinate and 0.125, 0.25, and 0.50% proparacaine hydrochloride were determined by monitoring changes in corneal touch threshold after applying each anesthetic. The level of corneal anesthesia necessary for applanation tonometry was also determined. The maximum increase in threshold that could be measured following instillation of 50 microliter of the drug was 200 mg/mm2 All 6 anesthetic solutions produced this amount of decreased corneal sensitivity. Recovery from the anesthetic was exponential for all concentrations; however, the lower doses had the shortest duration. For applanation tonometry, the corneal threshold for touch must be 75 mg/mm2 or higher. We conclude that a quarter to a half of the commonly used anesthetic dose is sufficient for routine tonometric evaluation.

Anesthetic gas exposure in veterinary clinics.

PubMed

Korczynski, R E

1999-06-01

Concerns were raised by several workers from veterinary clinics in Manitoba, Canada, regarding potential exposure to isoflurane and halothane during anesthetic administration. There has been no guideline established for isoflurane by the American Conference of Governmental Industrial Hygienist (ACGIH) or a Permissible Exposure Limit by the Occupational Safety and Health Administration (OSHA) or a recommended exposure limit (REL) by the National Institute for Occupational Safety and Health (NIOSH). The ACGIH TLV-TWA for halothane is 50 ppm and NIOSH has established 2 ppm as a recommended level based on an one-hour sampling. OSHA has established no guideline for halothane. The Miran IB Portable Ambient Air Analyzer was used to conduct real-time sampling and to identify leaks during administration. All veterinary clinics inspected had installed the passive waste gas scavenging system. Ten clinics were each monitored during anesthetic gas delivery for one surgical procedure performed. Induction was 4 to 5 percent and maintenance 1.5 to 2.5 percent. Nine clinics were small animal practices and the tenth was an equine clinic. Veterinarians' personal exposures were higher than the assistants'. Veterinarians' personal exposures for isoflurane ranged from 1.3 to 13 ppm (AM = 5.3; SD +/- 2.7; GM = 4.6; GSD +/- 1.6) and for their assistants, personal exposures ranged from 1.2 to 9 ppm (AM = 4.7; SD +/- 2.5; GM = 3.9; GSD +/- 1.6). Veterinarians' personal exposures for halothane ranged from 0.7 to 12 ppm (AM = 4.2; SD +/- 3.6; GM = 2.9; GSD +/- 1.4) and for their assistants, personal exposures ranged from 0.4 to 3.2 ppm (AM = 1.8; SD +/- 1.0; GM = 1.5; GSD +/- 1.7). One clinic had significant leaks in the anesthetic gas delivery lines. Personal halothane exposure for the veterinarian at this clinic was 7.2 to 65 ppm (AM = 18.0; SD +/- 11.5; GM = 15.9; GSD +/- 1.8). Based on this study, worker exposures were acceptable. Peak exposures were recorded when the cuffed endotracheal

Anesthetics and red blood cell rheology

NASA Astrophysics Data System (ADS)

Aydogan, Burcu; Aydogan, Sami

2014-05-01

There are many conditions where it is useful for anesthetists to have a knowledge of blood rheology. Blood rheology plays an important role in numerous clinical situations. Hemorheologic changes may significantly affect the induction and recovery times with anesthetic agents. But also, hemorheologic factors are directly or indirectly affected by many anesthetic agents or their metabolites. In this review, the blood rheology with special emphasis on its application in anesthesiology, the importance hemorheological parameters in anesthesiology and also the effect of some anesthetic substances on red blood cell rheology were presented.

Adsorptive conversion of nitrogen dioxide from etching vent gases over activated carbon.

PubMed

Fang, Mei-Ling; Wu, Ching-Yi; Chou, Ming-Shean

2018-04-13

Some metal etching operations emit limited flow rates of waste gases with reddish-brown NO 2 fume, which may cause visual and acidic-odor complaints, as well as negative health effects. In this study, tests were performed by passing caustic-treated waste gases vented from Al-etching operations through columns packed either with virgin or regenerated granular activated carbon (GAC) to test their adsorptive conversion performance of NO 2 in the gases. The gases contained 5-55 ppm NO 2 and acetic and nitric acids of below 3 ppm. Exhausted carbon was regenerated by scrubbing it with caustic solution and water, and dried for further adsorption tests. Results indicate that with an (empty bed residence time (EBRT) of 0.15 sec for the gas through the GAC-packed space, around 60% of the influent NO 2 of 54 ppm could be removed, and 47% of the removed NO 2 was converted by and desorbed from the carbon as NO. GAC used in the present study could be regenerated at least twice to restore its capacity for NO 2 adsorption. Within EBRTs of 0.076-0.18 sec, the adsorptive conversion capacity was linearly varied with EBRT. In practice, with an EBRT of 0.20 sec, a conversion capacity of 0.80 kg NO 2 (kg GAC) -1 with an influent NO 2 of 40 ppm can be used as a basis for system design. Some metal etching operations emit waste gases with reddish-brown (yellow when diluted) NO 2 fume which may cause visual and acidic-odor complaints, as well as negative health effects. This study provides a simple process for the adsorptive conversion of NO 2 in caustic-treated waste gases vented from metal-etching operations through a GAC column. With an EBRT of 0.20 sec, a conversion capacity of 0.80 kg NO 2 (kg GAC) -1 with an influent NO 2 of 40 ppm can be used as a basis for system design. Saturated GAC can be regenerated at least twice by simply scrubbing it with aqueous caustic solution.

Anesthetic Agent-Specific Effects on Synaptic Inhibition

PubMed Central

MacIver, M. Bruce

2014-01-01

Background Anesthetics enhance gamma-aminobutyric acid (GABA)-mediated inhibition in the central nervous system. Different agents have been shown to act on tonic versus synaptic GABA receptors to different degrees, but it remains unknown whether different forms of synaptic inhibition are also differentially engaged. With this in mind, we tested the hypothesis that different types of GABA-mediated synapses exhibit different anesthetic sensitivities. The present study compared effects produced by isoflurane, halothane, pentobarbital, thiopental and propofol on paired pulse GABAA receptor-mediated synaptic inhibition. Effects on glutamate-mediated facilitation were also studied. Methods Synaptic responses were measured in rat hippocampal brain slices. Orthodromic paired pulse stimulation was used to assess anesthetic effects on either glutamate-mediated excitatory inputs or GABA-mediated inhibitory inputs to CA1 neurons. Antidromic stimulation was used to assess anesthetic effects on CA1 background excitability. Agents were studied at equi-effective concentrations for population spike depression to compare their relative degree of effect on synaptic inhibition. Results Differing degrees of anesthetic effect on paired pulse facilitation at excitatory glutamate synapses were evident, and blocking GABA inhibition revealed a previously unseen presynaptic action for pentobarbital. Although all five anesthetics depressed synaptically evoked excitation of CA1 neurons, the involvement of enhanced GABA-mediated inhibition differed considerably among agents. Single pulse inhibition was enhanced by propofol, thiopental and pentobarbital, but only marginally by halothane and isoflurane. In contrast, isoflurane enhanced paired pulse inhibition strongly, as did thiopental, but propofol, pentobarbital and halothane were less effective. Conclusions These observations support the idea that different GABA synapses use receptors with differing subunit compositions, and that anesthetics

Vapor Pressures of Anesthetic Agents at Temperatures below Zero Degrees Celsius and a Novel Anesthetic Delivery Device

PubMed Central

Schenning, Katie J.; Casson, Henry; Click, Sarah V.; Brambrink, Lucas; Chatkupt, Thomas T.; Alkayed, Nabil J.; Hutchens, Michael P.

2016-01-01

At room temperature, the vapor pressures of desflurane, isoflurane, and sevoflurane are well above the clinically useful range. We hypothesized that therapeutic concentrations of these agents could be achieved at temperatures below zero, but the vapor pressure-temperature relationship is unknown below zero. Secondarily, we hypothesized that this relationship could be exploited to deliver therapeutic-range concentrations of anesthetic vapor. We therefore set out to determine the low temperature-vapor pressure relationships of each anesthetic agent thereby identifying the saturated vapor concentration of each agent at any temperature below zero. To test our hypothesis, we measured the saturated vapor concentration at 1 atmosphere of pressure for temperatures between -60°C and 0°C thus developing an empiric relationship for each agent. There was consistency in repeated experiments for all three agents. To test the empiric data we constructed a digitally-controlled thermoelectric anesthetic vaporizer, characterized the device, and used it to deliver anesthetic vapor to laboratory mice. We report, for the first time, the temperature-vapor pressure relationship at temperatures below 0°C for desflurane, isoflurane, and sevoflurane as well as the TMAC of these agents: the temperature at which the vapor pressure is equal to the minimum alveolar concentration. We describe the construction and limited validation of an anesthetic vaporizer prototype based on this principle. We conclude that clinically relevant concentrations of volatile anesthetics may be achieved at low temperatures. PMID:27632346

Vapor Pressures of Anesthetic Agents at Temperatures Below 0°C and a Novel Anesthetic Delivery Device.

PubMed

Schenning, Katie J; Casson, Henry; Click, Sarah V; Brambrink, Lucas; Chatkupt, Thomas T; Alkayed, Nabil J; Hutchens, Michael P

2017-02-01

At room temperature, the vapor pressures of desflurane, isoflurane, and sevoflurane are well above the clinically useful range. We hypothesized that therapeutic concentrations of these agents could be achieved at temperatures below 0°C, but the vapor pressure-temperature relationship is unknown below 0. Second, we hypothesized that this relationship could be exploited to deliver therapeutic-range concentrations of anesthetic vapor. We therefore set out to determine the low temperature-vapor pressure relationships of each anesthetic agent, thereby identifying the saturated vapor concentration of each agent at any temperature below 0°C. To test our hypothesis, we measured the saturated vapor concentration at 1 atm of pressure for temperatures between -60 and 0°C, thus developing an empiric relationship for each agent. There was consistency in repeated experiments for all 3 agents. To test the empiric data, we constructed a digitally controlled thermoelectric anesthetic vaporizer, characterized the device, and used it to deliver anesthetic vapor to laboratory mice. We report, for the first time, the temperature-vapor pressure relationship at temperatures below 0°C for desflurane, isoflurane, and sevoflurane as well as the TMAC of these agents: the temperature at which the vapor pressure is equal to the minimum alveolar concentration. We describe the construction and limited validation of an anesthetic vaporizer prototype on the basis of this principle. We conclude that clinically relevant concentrations of volatile anesthetics may be achieved at low temperatures.

Interaction of Local Anesthetics with Biomembranes Consisting of Phospholipids and Cholesterol: Mechanistic and Clinical Implications for Anesthetic and Cardiotoxic Effects

PubMed Central

2013-01-01

Despite a long history in medical and dental application, the molecular mechanism and precise site of action are still arguable for local anesthetics. Their effects are considered to be induced by acting on functional proteins, on membrane lipids, or on both. Local anesthetics primarily interact with sodium channels embedded in cell membranes to reduce the excitability of nerve cells and cardiomyocytes or produce a malfunction of the cardiovascular system. However, the membrane protein-interacting theory cannot explain all of the pharmacological and toxicological features of local anesthetics. The administered drug molecules must diffuse through the lipid barriers of nerve sheaths and penetrate into or across the lipid bilayers of cell membranes to reach the acting site on transmembrane proteins. Amphiphilic local anesthetics interact hydrophobically and electrostatically with lipid bilayers and modify their physicochemical property, with the direct inhibition of membrane functions, and with the resultant alteration of the membrane lipid environments surrounding transmembrane proteins and the subsequent protein conformational change, leading to the inhibition of channel functions. We review recent studies on the interaction of local anesthetics with biomembranes consisting of phospholipids and cholesterol. Understanding the membrane interactivity of local anesthetics would provide novel insights into their anesthetic and cardiotoxic effects. PMID:24174934

The Differential Effects of Anesthetics on Bacterial Behaviors

PubMed Central

Chamberlain, Matthew; Koutsogiannaki, Sophia; Schaefers, Matthew; Babazada, Hasan; Liu, Renyu; Yuki, Koichi

2017-01-01

Volatile anesthetics have been in clinical use for a long period of time and are considered to be promiscuous by presumably interacting with several ion channels in the central nervous system to produce anesthesia. Because ion channels and their existing evolutionary analogues, ion transporters, are very important in various organisms, it is possible that volatile anesthetics may affect some bacteria. In this study, we hypothesized that volatile anesthetics could affect bacterial behaviors. We evaluated the impact of anesthetics on bacterial growth, motility (swimming and gliding) and biofilm formation of four common bacterial pathogens in vitro. We found that commonly used volatile anesthetics isoflurane and sevoflurane affected bacterial motility and biofilm formation without any effect on growth of the common bacterial pathogens studied here. Using available Escherichia coli gene deletion mutants of ion transporters and in silico molecular docking, we suggested that these altered behaviors might be at least partly via the interaction of volatile anesthetics with ion transporters. PMID:28099463

A Guideline to Local Anesthetic Allergy Testing

PubMed Central

Canfield, David W.; Gage, Tommy W.

1987-01-01

Patients with a history of adverse reactions to a local anesthetic may often be incorrectly labeled as “allergic.” Determining if a patient is allergic to a local anesthetic is essential in the selection of appropriate pain control techniques. Local anesthetic allergy testing may be performed safely and with reasonable accuracy by a knowledgeable practitioner. This paper presents guidelines for an allergy testing method. ImagesFigure 1 PMID:3318567

Anesthetic effects in Alzheimer transgenic mouse models.

PubMed

Tang, Junxia X; Eckenhoff, Maryellen F

2013-12-02

Research has improved the diagnosis of Alzheimer's disease, and at earlier stages, but effective therapy continues to be elusive. Current effort is focused on delay. Environmental factors are thought to interact with genetics to modulate the progression of the disease, and one such environmental factor is exposure to general anesthetics. The possibility that some anesthetic effects have long-term consequences is of general interest and concern. The difficulty of studying a chronic, age-related disease in humans combined with the fact that anesthetics are rarely given without surgery, has led to a focus on animal models. Transgenic mouse models have been developed to mimic the hallmarks of Alzheimer's disease, including amyloid beta accumulation (plaque), neurofibrillary tangles, and cognitive dysfunction. While none of the models recapitulate the human disease with high fidelity, they allow a first look at anesthetic-Alzheimer interactions in a reasonable time frame. In studies found to date, none have concluded that anesthetics alone cause a significant change in cognitive decline, but rather an acceleration in Alzheimer neuropathology. Further studies are required to define the best anesthetic paradigm for our elderly population to mitigate changes in neuropathology and potentially cognition. Copyright © 2012 Elsevier Inc. All rights reserved.

The efficacy of eutectic mixture of local anesthetics as a topical anesthetic agent used for dental procedures: A brief review

PubMed Central

Daneshkazemi, Alireza; Abrisham, Seyyed Mohammad; Daneshkazemi, Pedram; Davoudi, Amin

2016-01-01

Dental pain management is one of the most critical aspects of modern dentistry which might affect patient's quality of life. Several methods are suggested to provide a painless situation for patients. Desensitization of the oral site using topical anesthetics is one of those methods. The improvements of topical anesthetic agents are probably one of the most important advances in dental science in the past 100 years. Most of them are safe and can be applied on oral mucosa with minimal irritation and allergic reactions. At present, these agents are various with different potent and indications. Eutectic mixture of local anesthetics (EMLA) (lidocaine + prilocaine) is a commercial anesthetic agent which has got acceptance among dental clinicians. This article provides a brief review about the efficacy of EMLA as a topical anesthetic agent when used during dental procedures. PMID:27746520

The efficacy of eutectic mixture of local anesthetics as a topical anesthetic agent used for dental procedures: A brief review.

PubMed

Daneshkazemi, Alireza; Abrisham, Seyyed Mohammad; Daneshkazemi, Pedram; Davoudi, Amin

2016-01-01

Dental pain management is one of the most critical aspects of modern dentistry which might affect patient's quality of life. Several methods are suggested to provide a painless situation for patients. Desensitization of the oral site using topical anesthetics is one of those methods. The improvements of topical anesthetic agents are probably one of the most important advances in dental science in the past 100 years. Most of them are safe and can be applied on oral mucosa with minimal irritation and allergic reactions. At present, these agents are various with different potent and indications. Eutectic mixture of local anesthetics (EMLA) (lidocaine + prilocaine) is a commercial anesthetic agent which has got acceptance among dental clinicians. This article provides a brief review about the efficacy of EMLA as a topical anesthetic agent when used during dental procedures.

Medical waste treatment and decontamination system

DOEpatents

Wicks, George G.; Schulz, Rebecca L.; Clark, David E.

2001-01-01

The invention discloses a tandem microwave system consisting of a primary chamber in which hybrid microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional hybrid microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C. Judson; MacKenzie, Patricia D.

1985-01-01

Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C.J.; Mackenzie, P.D.

1982-09-03

Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

Electrochemical processing of solid waste

NASA Technical Reports Server (NTRS)

Bockris, John OM.

1987-01-01

An investigation of electrochemical waste treatment methods suitable for closed, or partially closed, life support systems for manned space exploration is discussed. The technique being investigated involves the electrolysis of solid waste where the aim is to upgrade waste material (mainly fecal waste) to generate gases that can be recycled in a space station or planetary space environment.

Tandem microwave waste remediation and decontamination system

DOEpatents

Wicks, George G.; Clark, David E.; Schulz, Rebecca L.

1999-01-01

The invention discloses a tandem microwave system consisting of a primary chamber in which microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

Destruction of PCDD/Fs by SCR from flue gases of municipal waste incinerator and metal smelting plant.

PubMed

Chang, Moo Been; Chi, Kai Hsien; Chang, Shu Hao; Yeh, Jhy Wei

2007-01-01

Partitioning of PCDD/F congeners between vapor/solid phases and removal and destruction efficiencies achieved with selective catalytic reduction (SCR) system for PCDD/Fs at an existing municipal waste incinerator (MWI) and metal smelting plant (MSP) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP, operating temperature: 230 degrees C), wet scrubbers (WS, operating temperature: 70 degrees C) and SCR (operating temperature: 220 degrees C) as major air pollution control devices (APCDs). PCDD/F concentration measured at stack gas of the MWI investigated is 0.728 ng-TEQ/Nm(3). The removal efficiency of WS+SCR system for PCDD/Fs reaches 93% in the MWI investigated. The MSP investigated is equipped with EP (operating temperature: 240 degrees C) and SCR (operating temperature: 290 degrees C) as APCDs. The flue gas sampling results also indicate that PCDD/F concentration treated with SCR is 1.35 ng-TEQ/Nm(3). The SCR system adopted in MSP can remove 52.3% PCDD/Fs from flue gases (SCR operating temperature: 290 degrees C, Gas flow rate: 660 kN m(3)/h). In addition, the distributions of PCDD/F congeners observed in the flue gases of the MWI and MSP investigated are significantly different. This study also indicates that the PCDD/F congeners measured in the flue gases of those two facilities are mostly distributed in vapor phase prior to the SCR system and shift to solid phase (vapor-phase PCDD/Fs are effectively decomposed) after being treated with catalyst. Besides, the results also indicate that with SCR highly chlorinated PCDD/F congeners can be transformed to lowly chlorinated PCDD/F congeners probably by dechlorination, while the removal efficiencies of vapor-phase PCDD/Fs increase with increasing chlorination.

Direct Activation of Sleep-Promoting VLPO Neurons by Volatile Anesthetics Contributes to Anesthetic Hypnosis

PubMed Central

Moore, Jason T; Chen, Jingqiu; Han, Bo; Meng, Qing Cheng; Veasey, Sigrid C; Beck, Sheryl G; Kelz, Max B

2013-01-01

Summary Background Despite seventeen decades of continuous clinical use, the neuronal mechanisms through which volatile anesthetics act to produce unconsciousness remain obscure. One emerging possibility is that anesthetics exert their hypnotic effects by hijacking endogenous arousal circuits. A key sleep-promoting component of this circuitry is the ventrolateral preoptic nucleus (VLPO), a hypothalamic region containing both state-independent neurons and neurons that preferentially fire during natural sleep. Results Using c-Fos immunohistochemistry as a biomarker for antecedent neuronal activity, we show that isoflurane and halothane increase the number of active neurons in the VLPO, but only when mice are sedated or unconscious. Destroying VLPO neurons produces an acute resistance to isoflurane-induced hypnosis. Electrophysiological studies prove that the neurons depolarized by isoflurane belong to the subpopulation of VLPO neurons responsible for promoting natural sleep, while neighboring non-sleep-active VLPO neurons are unaffected by isoflurane. Finally, we show that this anesthetic-induced depolarization is not solely due to a presynaptic inhibition of wake-active neurons as previously hypothesized, but rather is due to a direct postsynaptic effect on VLPO neurons themselves arising from the closing of a background potassium conductance. Conclusions Cumulatively, this work demonstrates that anesthetics are capable of directly activating endogenous sleep-promoting networks and that such actions contribute to their hypnotic properties. PMID:23103189

Direct activation of sleep-promoting VLPO neurons by volatile anesthetics contributes to anesthetic hypnosis.

PubMed

Moore, Jason T; Chen, Jingqiu; Han, Bo; Meng, Qing Cheng; Veasey, Sigrid C; Beck, Sheryl G; Kelz, Max B

2012-11-06

Despite seventeen decades of continuous clinical use, the neuronal mechanisms through which volatile anesthetics act to produce unconsciousness remain obscure. One emerging possibility is that anesthetics exert their hypnotic effects by hijacking endogenous arousal circuits. A key sleep-promoting component of this circuitry is the ventrolateral preoptic nucleus (VLPO), a hypothalamic region containing both state-independent neurons and neurons that preferentially fire during natural sleep. Using c-Fos immunohistochemistry as a biomarker for antecedent neuronal activity, we show that isoflurane and halothane increase the number of active neurons in the VLPO, but only when mice are sedated or unconscious. Destroying VLPO neurons produces an acute resistance to isoflurane-induced hypnosis. Electrophysiological studies prove that the neurons depolarized by isoflurane belong to the subpopulation of VLPO neurons responsible for promoting natural sleep, whereas neighboring non-sleep-active VLPO neurons are unaffected by isoflurane. Finally, we show that this anesthetic-induced depolarization is not solely due to a presynaptic inhibition of wake-active neurons as previously hypothesized but rather is due to a direct postsynaptic effect on VLPO neurons themselves arising from the closing of a background potassium conductance. Cumulatively, this work demonstrates that anesthetics are capable of directly activating endogenous sleep-promoting networks and that such actions contribute to their hypnotic properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adsorption of Dissolved Gases (CH4, CO2, H2, Noble Gases) by Water-Saturated Smectite Clay Minerals

NASA Astrophysics Data System (ADS)

Bourg, I. C.; Gadikota, G.; Dazas, B.

2016-12-01

Adsorption of dissolved gases by water-saturated clay minerals plays important roles in a range of fields. For example, gas adsorption in on clay minerals may significantly impact the formation of CH4 hydrates in fine-grained sediments, the behavior of CH4 in shale, CO2 leakage across caprocks of geologic CO2 sequestration sites, H2 leakage across engineered clay barriers of high-level radioactive waste repositories, and noble gas geochemistry reconstructions of hydrocarbon migration in the subsurface. Despite its importance, the adsorption of gases on clay minerals remains poorly understood. For example, some studies have suggested that clay surfaces promote the formation of CH4 hydrates, whereas others indicate that clay surfaces inhibit the formation of CH4 hydrates. Here, we present molecular dynamics (MD) simulations of the adsorption of a range of gases (CH4, CO2, H2, noble gases) on clay mineral surfaces. Our results indicate that the affinity of dissolved gases for clay mineral surfaces has a non-monotone dependence on the hydrated radius of the gas molecules. This non-monotone dependence arises from a combination of two effects: the polar nature of certain gas molecules (in particular, CO2) and the templating of interfacial water structure by the clay basal surface, which results in the presence of interfacial water "cages" of optimal size for intermediate-size gas molecules (such as Ne or Ar).

The acute toxicity of local anesthetics.

PubMed

Mather, Laurence E

2010-11-01

Systemic toxicity, usually from overdose or intravascular dose, is feared because it mainly affects the heart and brain, and may be acutely life-threatening. Pharmacological studies of local anesthetic toxicity have largely been reviewed primarily relating to the evaluation of ropivacaine and levobupivacaine during the past decade. This review/opinion focuses more on the principles and concepts underlying the main models used, from chemical pharmacological and pharmacokinetic perspectives. Research models required to produce pivotal toxicity data are discussed. The potencies for neural blockade and systemic toxicity are associated across virtually all models, with some deviations through molecular stereochemistry. These models show that all local anesthetics can produce direct cardiovascular system toxicity and CNS excitotoxicity that may further affect the cardiovascular system response. Whereas the longer-acting local anesthetics are more likely to cause cardiac death by malignant arrhythmias, the shorter-acting agents are more likely to cause cardiac contraction failure. In most models, equi-anesthetic doses of ropivacaine and levobupivacaine are less likely to produce serious toxicity than bupivacaine. Of the various models, this reviewer favors a whole-body large animal preparation because of the comprehensive data collection possible. The conscious sheep preparation has contributed more than any other, and may be regarded as the de facto 'standard' experimental model for concurrent study of local anesthetic toxicity ± pharmacokinetics, using experimental designs that can reproduce the toxicity seen in clinical accidents.

Effects of changing body position on oxygenation and arterial blood pressures in foals anesthetized with guaifenesin, ketamine, and xylazine.

PubMed

Braun, Christina; Trim, Cynthia M; Eggleston, Randy B

2009-01-01

To investigate the impact of a change in body position on blood gases and arterial blood pressures in foals anesthetized with guaifenesin, ketamine, and xylazine. Prospective, randomized experimental study. Twelve Quarter Horse foals, age of 5.4 +/-0.9 months and weighing 222 +/- 48 kg. Foals were anesthetized with guaifenesin, ketamine, and xylazine for 40 minutes in lateral recumbency and then assigned to a change in lateral recumbency after hoisting (Group 1, n = 6), or no change (Group 2, n = 6). Oxygen 15 L minute(-1) was insufflated into the endotracheal tube throughout anesthesia. Arterial blood pressure, heart rate, respiratory rate (f(R)), inspired fraction of oxygen (FIO(2)), and end-tidal carbon dioxide (PE'CO(2)) were measured every 5 minutes. Arterial pH and blood gases [arterial partial pressure of oxygen (PaO(2)), arterial partial pressure of carbon dioxide (PaCO(2))] were measured at 10, 30, and 40 minutes after induction, and 5 minutes after hoisting. Alveolar dead space ventilation and PaO(2)/FIO(2) were calculated. Two repeated measures models were used. All hypothesis tests were two-sided and significance level was alpha = 0.05. All values are presented as least square means +/- SE. Values at time-matched points from the two groups were not significantly different so they were combined. Arterial partial pressure of oxygen decreased significantly from 149 +/- 14.4 mmHg before hoisting to 92 +/- 11.6 mmHg after hoisting (p = 0.0013). The PaO(2)/FIO(2) ratio decreased from 275 +/- 30 to 175 +/- 24 (p = 0.0055). End-tidal carbon dioxide decreased significantly from 48.7 +/- 1.6 to 44.5 +/- 1.2 mmHg (p = 0.021). Arterial partial pressure of carbon dioxide, blood pressures and heart rates measured 5 minutes after hoisting were not different from measurements obtained before hoisting. Hoisting decreased PaO(2) in anesthetized healthy foals. Administration of supplemental oxygen is recommended to counter the decrease in oxygenation and PaO(2

Minimum anesthetic volume in regional anesthesia by using ultrasound-guidance.

PubMed

Di Filippo, Alessandro; Falsini, Silvia; Adembri, Chiara

2016-01-01

The ultrasound guidance in regional anesthesia ensures the visualization of needle placement and the spread of Local Anesthetics. Over the past few years there was a substantial interest in determining the Minimum Effective Anesthetic Volume necessary to accomplish surgical anesthesia. The precise and real-time visualization of Local Anesthetics spread under ultrasound guidance block may represent the best requisite for reducing Local Anesthetics dose and Local Anesthetics-related effects. We will report a series of studies that have demonstrated the efficacy of ultrasound guidance blocks to reduce Local Anesthetics and obtain surgical anesthesia as compared to block performed under blind or electrical nerve stimulation technique. Unfortunately, the results of studies are widely divergent and not seem to indicate a dose considered effective, for each block, in a definitive way; but it is true that, through the use of ultrasound guidance, it is possible to reduce the dose of anesthetic in the performance of anesthetic blocks. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Anesthetic cartridge system under evaluation.

PubMed

Cooley, R L; Lubow, R M

1981-01-01

The problem of glass breakage in the local anesthetic cartridge system was evaluated under laboratory conditions with a mechanical testing machine. The anticipated breakage of the glass did not occur with any frequency, as the rubber stopper produced more uniform failures of the system. The glass cartridge appeared to be quite reliable and resistant to breakage.Local anesthetics have been used for many years to provide patients temporary freedom from pain. Local anesthetic solutions are in wide use in both dentistry and medicine and are the most frequently used drugs in dentistry. Various estimates place the number of injections at approximately one half million daily or 125 million injections per year.These drugs and the armamentarium necessary to administer them have proven to be safe and reliable. Only rarely are there reports of sensitivity to the anesthetic solution or breakage of needles.. Sterility of the solutions has not been a problem as they are carefully processed and evaluated at the factory. Although there are sporadic reports of loss of sterility, this has been attributed to the reuse of the anesthetic cartridges on more than one patient. Monheim states "The success of the cartridge system in dentistry has been due to the sincerity, honesty, and high standards of the manufacturers in giving the profession a near-perfect product." However, on occassion a glass cartridge will break or shatter when inserting the harpoon into the rubber stopper or even during injection. Cooley et al reported on eye injuries occurring in the dental office, one of which was due to glass from a local anesthetic cartridge that exploded and propelled particles into the patient's eye. Forrest evaluated syringes, needles, and cartridges and reported that one brand (made in Britain) fractured more often than any other, but that the fracture rate was too low to be of any consequence.It is apparent that glass cartridges will fracture or burst from time to time. This study

Anesthetic Cartridge System Under Evaluation

PubMed Central

Cooley, Robert L.; Lubow, Richard M.

1981-01-01

The problem of glass breakage in the local anesthetic cartridge system was evaluated under laboratory conditions with a mechanical testing machine. The anticipated breakage of the glass did not occur with any frequency, as the rubber stopper produced more uniform failures of the system. The glass cartridge appeared to be quite reliable and resistant to breakage. Local anesthetics have been used for many years to provide patients temporary freedom from pain. Local anesthetic solutions are in wide use in both dentistry and medicine and are the most frequently used drugs in dentistry. Various estimates place the number of injections at approximately one half million daily or 125 million injections per year. These drugs and the armamentarium necessary to administer them have proven to be safe and reliable. Only rarely are there reports of sensitivity to the anesthetic solution or breakage of needles.. Sterility of the solutions has not been a problem as they are carefully processed and evaluated at the factory. Although there are sporadic reports of loss of sterility, this has been attributed to the reuse of the anesthetic cartridges on more than one patient. Monheim states “The success of the cartridge system in dentistry has been due to the sincerity, honesty, and high standards of the manufacturers in giving the profession a near-perfect product.” However, on occassion a glass cartridge will break or shatter when inserting the harpoon into the rubber stopper or even during injection. Cooley et al reported on eye injuries occurring in the dental office, one of which was due to glass from a local anesthetic cartridge that exploded and propelled particles into the patient's eye. Forrest evaluated syringes, needles, and cartridges and reported that one brand (made in Britain) fractured more often than any other, but that the fracture rate was too low to be of any consequence. It is apparent that glass cartridges will fracture or burst from time to time. This study

Safety considerations of anesthetic drugs in children.

PubMed

Brown, Raeford E

2017-04-01

Great strides have been made in the last twenty years in providing safe anesthesia care for infants and children. Despite a historical record of safety, recent findings have called to question the toxicities of many anesthetic agents. Observations concerning the inherent safety of these agents, their appropriate management in infants, and new findings which suggest overlooked toxicities will be discussed. Areas covered: A literature search using Pub Med identified journal articles relating to the safety of anesthetic agents in infants and children. From this group, representative classical articles, as well as more recent offerings, were chosen that were germane to the topic of anesthetic drug safety in children. Expert opinion: Anesthetic agents used in children in the US are generally safe in the short term and are administered to thousands of children daily without demonstrable harm. The question of a deleterious effect of anesthetics on the developing central nervous system when used for long periods and on multiple occasions continues to be open to debate. Conservative elective management of these agents in infants and young children is reasonable until such time as more is known about the toxicities on the central nervous system.

Altered states: psychedelics and anesthetics.

PubMed

Icaza, Eduardo E; Mashour, George A

2013-12-01

The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness.

An update on anesthetics and impact on the brain.

PubMed

Fodale, Vincenzo; Tripodi, Vincenzo F; Penna, Olivia; Famà, Fausto; Squadrito, Francesco; Mondello, Epifanio; David, Antonio

2017-09-01

While anesthetics are indispensable clinical tools and generally considered safe and effective, a growing concern over the potential neurotoxicity of anesthesia or specific anesthetic agents has called into question the safety of general anesthetics, especially when administered at extremes of age. Areas covered: This article reviews and updates research findings on the safety of anesthesia and anesthetics in terms of long-term neurotoxicity, with particular focus on postoperative cognitive dysfunctions, Alzheimer's disease and dementias, developing brain, post-operative depression and autism spectrum disorder. Expert opinion: Exposure to general anesthetics is potentially harmful to the human brain, and the consequent long-term cognitive deficits should be classified as an iatrogenic pathology, and considered a public health problem. The fact that in laboratory and clinical research only certain anesthetic agents and techniques, but not others, appear to be involved, raises the problem on what is the safest and the least safe anesthetic to maximize anesthesia efficiency, avoid occurrence of adverse events, and ensure patient safety. New trends in research are moving toward the theory that neuroinflammation could be the hallmark of, or could have a pivotal role in, several neurological disorders.

Effect of topical anesthetics on intraocular pressure and pachymetry.

PubMed

Montero, J A; Ruiz-Moreno, J M; Fernandez-Munoz, M; Rodriguez-Palacios, M I

2008-01-01

The determination of intraocular pressure (IOP) by noncontact tonometry (NCT) has been reported to be affected by central corneal thickness (CCT) and by the instillation of topical anesthetics. In order to determine the influence of topical anesthetics on CCT and IOP measured by NCT, 80 eyes from 49 patients were examined before and after the instillation of topical anesthetics. Average age was 55.3 years (SD 18.4, range 18 to 93). Twenty-eight patients were female and 21 were male. Average basal IOP was 16.1 mmHg (SD 5.2, range 8 to 35.3). IOP was 14.8 mmHg (SD 4.6, 7.4 to 32.4) (p=0.0005, Student t test for paired data) 5 minutes after topical anesthetics instillation. CCT averaged 541 micronm (SD 32, range 482 to 604) before topical anesthetic drops and 541 micronm (SD 32, 490 to 607, p=0.89, Student t test for paired data) 5 minutes after topical anesthetics instillation. The study confirms that the instillation of topical anesthetics causes a reduction in IOP. These changes do not seem to be associated with changes in CCT.

Benzocaine as an anesthetic for striped bass

USGS Publications Warehouse

Gilderhus, Philip A.; Lemm, Carol A.; Woods, L. Curry

1991-01-01

Benzocaine was tested as an anesthetic on juvenile and mature adult striped bass (Morone saxatilis ). Concentrations of 55 mg/L at 22 degree C to 80 mg/L at 11 degree C effectively anesthetized fish in about 3 min. Recovery was more rapid as temperature increased. Fish survived concentrations of twice the effective concentration and exposure times up to 60 min at the effective concentration. Striped bass required higher concentrations for anesthetization than had been previously demonstrated for salmonid fishes, but safety margins for both concentration and exposure time were wider than for the salmonids.

Can anesthetic treatment worsen outcome in status epilepticus?

PubMed

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". Copyright © 2015 Elsevier Inc. All rights reserved.

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

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

Stability of local anesthetics in the dental cartridge.

PubMed

Hondrum, S O; Seng, G F; Rebert, N W

1993-01-01

Recent manufacturer recalls of local anesthetics have emphasized the problems with storage stability. This article reviews the principles of drug stability, mechanisms of degradation of commonly used vasoconstrictors, research on the stability of commercially produced local anesthetic preparations, and possible effects of the container-closure system. The review concludes with a list of practical and clinical suggestions on how to minimize storage stability problems with dental local anesthetics.

Anesthetic management during cardiopulmonary bypass: a systematic review.

PubMed

Barry, Aaron E; Chaney, Mark A; London, Martin J

2015-04-01

Cardiopulmonary bypass (CPB) required for cardiac surgery presents unique challenges to the cardiac anesthesiologist responsible for providing the 3 most basic facets of any anesthetic: amnesia, analgesia, and muscle relaxation. Unique pathophysiologic changes during CPB result in pharmacokinetic alterations that impact the serum and tissue concentrations of IV and volatile anesthetics. Similarly, CPB causes pharmacodynamic alterations that impact anesthetic efficacy. The clinical significance of these alterations represents a "moving target" as practice evolves and the technology of CPB circuitry advances. In addition, perfusionists choose, modify, and maintain the CPB circuitry and membrane oxygenator. Thus, their significance may not be fully appreciated by the anesthesiologist. These issues have a profound impact on the anesthetic state of the patient. The delivery and maintenance of anesthesia during CPB present unique challenges. The perfusionist may be directly responsible for the delivery of anesthetic during CPB, a situation unique to the cardiac suite. In addition, monitors of anesthetic depth-assessment of clinical signs, hemodynamic indicators, the bispectral index monitor, end-tidal anesthetic concentration, or twitch monitoring-are often absent, unreliable, or directly impacted by the unique pathophysiology associated with CPB. The magnitude of these challenges is reflected in the higher incidence of intraoperative awareness during cardiac surgery. Further complicating matters are the lack of specific clinical guidelines and varying international policies regarding medical device specifications that add further layers of complexity and introduce practice variability both within institutions and among nations. We performed a systematic survey of the literature to identify where anesthetic practice during CPB is evidence based (or not), identify gaps in the literature to guide future investigations, and explore the implications of evolving surgical

Anesthetic variation and potential impact of anesthetics used during endovascular management of acute ischemic stroke.

PubMed

Sivasankar, Chitra; Stiefel, Michael; Miano, Todd A; Kositratna, Guy; Yandrawatthana, Sukanya; Hurst, Robert; Kofke, W Andrew

2016-11-01

Many authors have reported that general anesthesia (GA), as a generic and uncharacterized therapy, is contraindicated for patients undergoing endovascular management of acute ischemic stroke (EMAIS). The recent American Heart Association update cautiously suggests that it might be reasonable to favor conscious sedation over GA during EMAIS. We are concerned that such recommendations will result in patients undergoing endovascular treatment without consideration of the effects of specific anesthetic agents and anesthetic dose, and without appropriate critical consideration of the individual patient's issues. We hypothesized that significant variation in anesthetic practice comprises GA, and that outcome differences among types of GA would arise. With IRB approval, we examined the records of patients who underwent anterior circulation EMAIS at the University of Pennsylvania from 2010 to 2015. Patients were managed by different anesthesiologists with no specific protocol. We analyzed American Society of Anesthesiologists status, NIH Stroke Scale, type of stroke, procedure, different types of anesthetic, blood pressure control, and outcome metrics. Modified Rankin Scale (mRS) scores were determined from medical records. GA was used in 91% of patients. Several types of GA were employed: intravenous, volatile, and intravenous/volatile combined. mRS scores ≤2 at discharge were observed in 42.8% of patients receiving volatile anesthesia and were better in patients receiving only volatile agents after induction of anesthesia (p<0.05). Our data support the notion that anesthetic techniques and associated physiology used in EMAIS are not homogeneous, making any statements about the effects of generic GA in stroke ambiguous. Moreover, our data suggest that the type of GA may affect the outcome after EMAIS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Exploring the modulation of hypoxia-inducible factor (HIF)-1α by volatile anesthetics as a possible mechanism underlying volatile anesthetic-induced CNS injury.

PubMed

Giles, Emma K; Lawrence, Andrew J; Duncan, Jhodie R

2014-09-01

This review summarizes recent research on the potential cognitive and behavioural abnormalities induced by exposure to volatile anesthetics and suggests a role of hypoxia-inducible factor (HIF)-1α in mediating these events. Volatile anesthetics are widely utilized in clinical and research settings, yet the long-term safety of exposure to these agents is under debate. Findings from various animal models suggest volatile anesthetics induce widespread apoptosis in the central nervous system (CNS) that correlates with lasting deficits in learning and memory. Longitudinal analysis of clinical data highlight an increased risk of developmental disorders later in life when children are exposed to volatile anesthetics, particularly when exposures occur over multiple sessions. However, the mechanisms underlying these events have yet to be established. Considering the extensive use of volatile anesthetics, it is crucial that these events are better understood. The possible role of HIF-1α in volatile anesthetic-induced CNS abnormalities will be suggested and areas requiring urgent attention will be outlined.

General Anesthetics and Molecular Mechanisms of Unconsciousness

PubMed Central

Forman, Stuart A.; Chin, Victor A.

2013-01-01

General anesthetic agents are unique in clinical medicine, because they are the only drugs used to produce unconsciousness as a therapeutic goal. In contrast to older hypotheses that assumed all general anesthetics produce their central nervous system effects through a common mechanism, we outline evidence that general anesthesia represents a number of distinct pharmacological effects that are likely mediated by different neural circuits, and perhaps via different molecular targets. Within the context of this neurobiological framework, we review recent molecular pharmacological and transgenic animal studies. These studies reveal that different groups of general anesthetics, which can be discerned based on their clinical features, produce unconsciousness via distinct molecular targets and therefore via distinct mechanisms. We further postulate that different types of general anesthetics selectively disrupt different critical steps (perhaps in different neuronal circuits) in the processing of sensory information and memory that results in consciousness. PMID:18617817

Research on the 2nd generation biofuel BIOXDIESEL in aspects of emission of toxic substances in exhaust gases

NASA Astrophysics Data System (ADS)

Struś, M. S.; Poprawski, W.; Rewolte, M.

2016-09-01

This paper presents results of research of Diesel engines emission of toxic substances in exhaust gases fuelled with a second generation biofuel BIOXDIESEL, which is a blend of Fatty Acid Ethyl Esters obtained from waste resources such waste vegetable and animal fats, bioethanol and standard Diesel fuel. Presented results are very promising, showing that the emission of toxic substances in exhaust gases are significantly reduced when fuelling with BIOXDIESEL fuel in comparison with standard Diesel fuel.

Nitrous Oxide and the Inhalation Anesthetics

PubMed Central

Becker, Daniel E; Rosenberg, Morton

2008-01-01

Nitrous oxide is the most commonly used inhalation anesthetic in dentistry and is commonly used in emergency centers and ambulatory surgery centers as well. When used alone, it is incapable of producing general anesthesia reliably, but it may be combined with other inhalation and/or intravenous agents in deep sedative/general anesthestic techniques. However, as a single agent, it has impressive safety and is excellent for providing minimal and moderate sedation for apprehensive dental patients. To gain a full appreciation of the pharmacology, physiologic influences, and proper use of nitrous oxide, one must compare it with other inhalation anesthetics. The purpose of this CE article is to provide an overview of inhalation anesthetics in general and to address nitrous oxide more specifically in comparison. PMID:19108597

The use of compound topical anesthetics: a review.

PubMed

Kravitz, Neal D

2007-10-01

The author reviewed the history of, federal regulations regarding, risks of and adverse drug reactions of five compound topical anesthetics: tetracaine, adrenaline/epinephrine and cocaine (TAC); lidocaine, adrenaline/epinephrine and tetracaine (LET); lidocaine, tetracaine and phenylephrine (TAC 20 percent Alternate); lidocaine, prilocaine and tetracaine (Profound); and lidocaine, prilocaine, tetracaine and phenylephrine with thickeners (Profound PET). The author reviewed clinical trials, case reports, descriptive articles, and U.S. Food and Drug Administration (FDA) regulations and recent public advisory warnings regarding the federal approval of and risks associated with the use of compound topical anesthetics. Compound topical anesthetics are neither FDA-regulated nor -unregulated. Some compounding pharmacies bypass the new FDA drug approval process, which is based on reliable scientific data and ensures that a marketed drug is safe, effective, properly manufactured and accurately labeled. Two deaths have been attributed to the lay use of compound topical anesthetics. In response, the FDA has announced the strengthening of its efforts against unapproved drug products. Compound topical anesthetics may be an effective alternative to local infiltration for some minimally invasive dental procedures; however, legitimate concerns exist in regard to their safety. Until they become federally regulated, compound topical anesthetics remain unapproved drug products whose benefits may not outweigh their risks for dental patients.

[Anesthetic management in bronchial asthma].

PubMed

Kozian, Alf; Schilling, Thomas; Hachenberg, Thomas

2016-06-01

In daily practice, acute and chronic pulmonary diseases are common issues presenting to the anesthetist. Respiratory physiology in general is affected by both general and regional anesthesia, which results in an increased number of perioperative complications in pulmonary risk patients. Therefore, anesthetic management of patients with bronchial asthma needs to address different clinical topics: the physical appearance of pulmonary disease, type and extent of surgical intervention as well as effects of therapeutic drugs, anesthetics and mechanical ventilation on respiratory function. The present work describes important precautions in preoperative scheduling of the asthmatic patient. In the operative course, airway manipulation and a number of anesthetics are able to trigger intraoperative bronchial spasm with possibly fatal outcome. It is essential to avoid these substances to prevent asthma attack. If asthmatic status occurs, appropriate procedures according to therapeutic standards have to be applied to the patient. Postoperatively, sufficient pain therapy avoids pulmonary complications and improves outcome. © Georg Thieme Verlag Stuttgart · New York.

Shedding Light on Anesthetic Mechanisms: Application of Photoaffinity Ligands

PubMed Central

Woll, Kellie A.; Dailey, William P.; Brannigan, Grace; Eckenhoff, Roderic G.

2016-01-01

Anesthetic photoaffinity ligands have had an increasing presence within anesthesiology research. These ligands mimic parent general anesthetics, and allow investigators to study anesthetic interactions with receptors and enzymes; identify novel targets; and determine distribution within biological systems. To date nearly all general anesthetics used in medicine have a corresponding photoaffinity ligand represented in the literature. In this review we examine all aspects of the current methodologies, including ligand design, characterization and deployment. Finally we offer points of consideration and highlight the future outlook as more photoaffinity ligands emerge within the field. PMID:27464974

Shedding Light on Anesthetic Mechanisms: Application of Photoaffinity Ligands.

PubMed

Woll, Kellie A; Dailey, William P; Brannigan, Grace; Eckenhoff, Roderic G

2016-11-01

Anesthetic photoaffinity ligands have had an increasing presence within anesthesiology research. These ligands mimic parent general anesthetics and allow investigators to study anesthetic interactions with receptors and enzymes; identify novel targets; and determine distribution within biological systems. To date, nearly all general anesthetics used in medicine have a corresponding photoaffinity ligand represented in the literature. In this review, we examine all aspects of the current methodologies, including ligand design, characterization, and deployment. Finally we offer points of consideration and highlight the future outlook as more photoaffinity ligands emerge within the field.

Induced Changes in Protein Receptors Conferring Resistance to Anesthetics

PubMed Central

Bertaccini, Edward J.; Trudell, James R.

2014-01-01

Purpose of review While general anesthetics have been provided effectively for many years, their exact molecular underpinnings remain relatively unknown. In this manuscript, we discuss the recent findings associated with resistance to anesthetic effects as a way of shedding light on these mechanisms. Recent findings The original theories of anesthetic action based upon their effects on cellular membranes have given way to specific theories concerning direct effects on ion channel proteins. These molecular targets are intimately involved in the conduct of neuronal signaling within the central nervous system and are thought to be essential in the modulation of conscious states. It is the lack of a thorough understanding of unperturbed consciousness that fosters great difficulty in understanding how anesthetics alter this conscious state. However, one very fruitful line of analysis in the quest for such answers lies in the examination of both in vitro and in vivo ion channel systems which seem to maintain variable levels of resistance to anesthetics. Summary Information about the possible targets and molecular nature of anesthetic action is being derived from studies of anesthetic resistance in GABA receptors, tandem pore potassium channels, and an apparently wide variety of protein systems within the nematode, C. elegans PMID:22614247

General anesthetics cause mitochondrial dysfunction and reduction of intracellular ATP levels

PubMed Central

Kishikawa, Jun-ichi; Inoue, Yuki; Fujikawa, Makoto; Nishimura, Kenji; Nakanishi, Atsuko; Tanabe, Tsutomu; Imamura, Hiromi

2018-01-01

General anesthetics are indispensable for effective clinical care. Although, the mechanism of action of general anesthetics remains controversial, lipid bilayers and proteins have been discussed as their targets. In this study, we focused on the relationship between cellular ATP levels and general anesthetics. The ATP levels of nematodes and cultured mammalian cells were decreased by exposure to three general anesthetics: isoflurane, pentobarbital, and 1-phenoxy-2-propanol. Furthermore, these general anesthetics abolished mitochondrial membrane potential, resulting in the inhibition of mitochondrial ATP synthesis. These results suggest that the observed decrease of cellular ATP level is a common phenomenon of general anesthetics. PMID:29298324

[Hazardous material and safety conditions in veterinary practice. 2: Flammable liquid, disinfectants and cleansing media, cytostatics, pressurized gases, liquid nitrogen, narcotic gases, mailing of diagnostic samples, hazardous waste].

PubMed

Sliwinski-Korell, A; Lutz, F

1998-05-01

In the last years the standards for professional handling of hazardous material as well as health and safety in the veterinary practice became considerably more stringent. This is expressed in various safety regulations, particularly the decree of hazardous material and the legislative directives concerning health and safety at work. In part 1, a definition based on the law for hazardous material was given and the potential risks were mentioned. The correct documentation regarding the protection of personal and the purchase, storage, working conditions and removal of hazardous material was explained. General rules for the handling of hazardous material were described. In part 2, partial emphasis is put on the handling of flammable liquids, disinfectants, cytostatica, pressurised gases, liquid nitrogen, narcotics, mailing of potentially infectious material and safe disposal of hazardous waste. Advice about possible unrecognized hazards and references are also given.

Vasoconstriction Potency Induced by Aminoamide Local Anesthetics Correlates with Lipid Solubility

PubMed Central

Sung, Hui-Jin; Ok, Seong-Ho; Sohn, Jin-Young; Son, Yong Hyeok; Kim, Jun Kyu; Lee, Soo Hee; Han, Jeong Yeol; Lim, Dong Hoon; Shin, Il-Woo; Lee, Heon-Keun; Chung, Young-Kyun; Choi, Mun-Jeoung; Sohn, Ju-Tae

2012-01-01

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. PMID:22778542

MicroRNAs: New Players in Anesthetic-Induced Developmental Neurotoxicity

PubMed Central

Twaroski, Danielle; Bosnjak, Zeljko J.; Bai, Xiaowen

2015-01-01

Growing evidence demonstrates that prolonged exposure to general anesthetics during brain development induces widespread neuronal cell death followed by long-term memory and learning disabilities in animal models. These studies have raised serious concerns about the safety of anesthetic use in pregnant women and young children. However, the underlying mechanisms of anesthetic-induced neurotoxicity are complex and are not well understood. MicroRNAs are endogenous, small, non-coding RNAs that have been implicated to play important roles in many different disease processes by negatively regulating target gene expression. A possible role for microRNAs in anesthetic-induced developmental neurotoxicity has recently been identified, suggesting that microRNA-based signaling might be a novel target for preventing the neurotoxicity. Here we provide an overview of anesthetic-induced developmental neurotoxicity and focus on the role of microRNAs in the neurotoxicity observed in both human stem cell-derived neuron and animal models. Aberrant expression of some microRNAs has been shown to be involved in anesthetic-induced developmental neurotoxicity, revealing the potential of microRNAs as therapeutic or preventive targets against the toxicity. PMID:26146587

Analysis of potential for reducing emissions of greenhouse gases in municipal solid waste in Brazil, in the state and city of Rio de Janeiro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loureiro, S.M., E-mail: saulo@lima.coppe.ufrj.br; Rovere, E.L.L., E-mail: emilio@ppe.ufrj.br; Mahler, C.F., E-mail: mahler0503@yahoo.com

2013-05-15

Highlights: ► We constructed future scenarios of emissions of greenhouse gases in waste. ► Was used the IPCC methodology for calculating emission inventories. ► We calculated the costs of abatement for emissions reduction in landfill waste. ► The results were compared to Brazil, state and city of Rio de Janeiro. ► The higher the environmental passive, the greater the possibility of use of biogas. - Abstract: This paper examines potential changes in solid waste policies for the reduction in GHG for the country of Brazil and one of its major states and cities, Rio de Janeiro, from 2005 to 2030.more » To examine these policy options, trends in solid waste quantities and associated GHG emissions are derived. Three alternative policy scenarios are evaluated in terms of effectiveness, technology, and economics and conclusions posited regarding optimal strategies for Brazil to implement. These scenarios are been building on the guidelines for national inventories of GHG emissions (IPCC, 2006) and adapted to Brazilian states and municipalities’ boundaries. Based on the results, it is possible to say that the potential revenue from products of solid waste management is more than sufficient to transform the current scenario in this country into one of financial and environmental gains, where the negative impacts of climate change have created a huge opportunity to expand infrastructure for waste management.« less

Solubility of Haloether Anesthetics in Human and Animal Blood

PubMed Central

Soares, Joao H. N.; Brosnan, Robert J.; Fukushima, Fabíola B.; Hodges, Joanne; Liu, Hong

2012-01-01

Background Anesthetic blood solubility predicts pharmacokinetics for inhaled agents and is essential for determination of blood anesthetic concentrations from end-tidal gas concentrations using Henry’s Law. Though used to model anesthetic effects in humans, there are limited interspecies solubility comparisons that include modern haloethers. This study aimed to measure hematocrit-adjusted blood:gas anesthetic partition coefficients (λB:G) for desflurane, sevoflurane, isoflurane, and methoxyflurane in humans and animals. Methods Whole blood was collected from 20 rats, 8 horses, and 4 each of cats, cattle, humans, dogs, goats, pigs, rabbits, and sheep. Plasma or cell volume was removed to adjust all samples to a packed cell volume of 40%. A single agent calibration gas headspace was added to blood in a glass syringe and was mixed and equilibrated at 37°C for 2 hours. Agent concentrations in the calibration gas and syringe headspace were measured using gas chromatography. Anesthetic solubility in saline, citrate-phosphate-dextrose-adenine, and olive oil were similarly measured. Results Except for goats, all animal species had at least one λB:G measurement that differed significantly from humans. For each agent, λB:G positively correlated with serum triglyceride concentrations, but this only explained 25% of interspecies variability. Desflurane was significantly less soluble in blood than sevoflurane in some species (e.g., humans) but not in others (e.g., rabbits). Conclusions Anesthetic partition coefficients differ significantly between humans and most animals for haloether anesthetics. Because of their similar λB:G values, goats may be a better animal model for inhaled anesthetic pharmacokinetics in people. PMID:22510863

Solubility of haloether anesthetics in human and animal blood.

PubMed

Soares, Joao H N; Brosnan, Robert J; Fukushima, Fabíola B; Hodges, Joanne; Liu, Hong

2012-07-01

Anesthetic blood solubility predicts pharmacokinetics for inhaled agents and is essential for determination of blood anesthetic concentrations from end-tidal gas concentrations using Henry's Law. Though used to model anesthetic effects in humans, there are limited interspecies solubility comparisons that include modern haloethers. This study aimed to measure hematocrit-adjusted blood:gas anesthetic partition coefficients (λ B:G) for desflurane, sevoflurane, isoflurane, and methoxyflurane in humans and animals. Whole blood was collected from 20 rats, 8 horses, and 4 each of cats, cattle, humans, dogs, goats, pigs, rabbits, and sheep. Plasma or cell volume was removed to adjust all samples to a packed cell volume of 40%. A single-agent calibration gas headspace was added to blood in a glass syringe and was mixed and equilibrated at 37°C for 2 h. Agent concentrations in the calibration gas and syringe headspace were measured using gas chromatography. Anesthetic solubility in saline, citrate-phosphate-dextrose-adenine, and olive oil were similarly measured. Except for goats, all animal species had at least one λ B:G measurement that differed significantly from humans. For each agent, λ B:G positively correlated with serum triglyceride concentrations, but this only explained 25% of interspecies variability. Desflurane was significantly less soluble in blood than sevoflurane in some species (e.g., humans) but not in others (e.g., rabbits). Anesthetic partition coefficients differ significantly between humans and most animals for haloether anesthetics. Because of their similar λ B:G values, goats may be a better animal model for inhaled anesthetic pharmacokinetics in people.

Anesthetic diffusion through lipid membranes depends on the protonation rate.

PubMed

Pérez-Isidoro, Rosendo; Sierra-Valdez, F J; Ruiz-Suárez, J C

2014-12-18

Hundreds of substances possess anesthetic action. However, despite decades of research and tests, a golden rule is required to reconcile the diverse hypothesis behind anesthesia. What makes an anesthetic to be local or general in the first place? The specific targets on proteins, the solubility in lipids, the diffusivity, potency, action time? Here we show that there could be a new player equally or even more important to disentangle the riddle: the protonation rate. Indeed, such rate modulates the diffusion speed of anesthetics into lipid membranes; low protonation rates enhance the diffusion for local anesthetics while high ones reduce it. We show also that there is a pH and membrane phase dependence on the local anesthetic diffusion across multiple lipid bilayers. Based on our findings we incorporate a new clue that may advance our understanding of the anesthetic phenomenon.

Anesthetic Diffusion Through Lipid Membranes Depends on the Protonation Rate

PubMed Central

Pérez-Isidoro, Rosendo; Sierra-Valdez, F. J.; Ruiz-Suárez, J. C.

2014-01-01

Hundreds of substances possess anesthetic action. However, despite decades of research and tests, a golden rule is required to reconcile the diverse hypothesis behind anesthesia. What makes an anesthetic to be local or general in the first place? The specific targets on proteins, the solubility in lipids, the diffusivity, potency, action time? Here we show that there could be a new player equally or even more important to disentangle the riddle: the protonation rate. Indeed, such rate modulates the diffusion speed of anesthetics into lipid membranes; low protonation rates enhance the diffusion for local anesthetics while high ones reduce it. We show also that there is a pH and membrane phase dependence on the local anesthetic diffusion across multiple lipid bilayers. Based on our findings we incorporate a new clue that may advance our understanding of the anesthetic phenomenon. PMID:25520016

A Survey of Waste Anesthetic Gas Levels in Selected USAF Veterinary Surgeries.

DTIC Science & Technology

1979-02-01

Gases and Vapors (19) that certain concentration levels should not be exceeded. These levels are: (1) 2 ppm for halothane and methoxyflurane . (2) 25 ppm...Soc. J. 22:330-337. 10. Chenoweth, M. B., Leong, B. K. J., Sparschu, G. L. and Torkelson, T. R. 1972. Toxicities of methoxyflurane , halothane and

Comparison of anesthetic agents in the sea otter

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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.

Advanced technologies and devices for inhalational anesthetic drug dosing.

PubMed

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

Antimicrobial Properties of Topical Anesthetic Liquids Containing Lidocaine or Benzocaine

PubMed Central

Morrow, Mark E.; Berry, Charles W.

1988-01-01

Six species of microorganisms commonly found within the oral cavity were exposed for either one minute or two hours to 5% lidocaine liquid topical anesthetic and benzocaine liquid topical anesthetic. Mixtures of microorganisms and anesthetics were diluted and plated onto a brain heart infusion medium. Reduction in cell viability was 73-100% after exposure to the anesthetic agents when compared with the saline/buffer controls. A significant reduction (p < .005) in cell growth by Streptococcus mutans, S. sanguis, S. mitis, S. salivarius, Actinomyces viscosus, and Candida albicans was associated with a one-minute and two-hour exposure to lidocaine, benzocaine, 5% lidocaine, and the benzocaine vehicle control. Five percent lidocaine reduced growth of the test orgainisms more than benzocaine in one-minute exposures to S. mutans, A. viscosus and S. salivarius and with a two-hour exposure to S. salivarius. Five percent lidocaine was bacteriocidal or fungicidal to all microorganisms for both time periods whereas, benzocaine liquid topical anesthetic was predominately bacteriostatic or fungistatic after one-minute exposures and bacteriocidal or fungicidal after two hours. The results indicated that two dental liquid topical anesthetics containing lidocaine or benzocaine possessed considerable antimicrobial activity to selected oral microorganisms. The exclusive use of a topical liquid anesthetic may be an adequate means to render the oral mucosa aseptic before injection of a local anesthetic. PMID:3278655

Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

NASA Technical Reports Server (NTRS)

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.

Breastfeeding Problems Following Anesthetic Administration

PubMed Central

Howie, William O.; McMullen, Patricia C.

2006-01-01

Research literature supports the notion that maternal comfort should be considered a priority and that mothers should receive adequate information regarding any drug prior to receiving that drug. Some studies indicate that difficulties with breastfeeding may be related to the amount of the anesthetic or analgesic that is administered to the mother. Thus, it seems wise to administer the lowest possible dose to the mother in order to minimize the amount of drug (or metabolite) exposure to the nursing infant. Infant exposure can be further reduced if breastfeeding is avoided during the times when the mother receives high doses of anesthetics and analgesics. However, because relatively small amounts of the drug are excreted into the breast milk, some mothers may opt to continue nursing after weighing the benefits of breastfeeding against the potential risk to the infant. Others may choose to “pump and dump” breast milk while they receive anesthetic or analgesic agents. Any concerns in this regard should be discussed with the anesthesia provider, preferably prior to labor or to any surgeries while breastfeeding. PMID:17541461

Breastfeeding problems following anesthetic administration.

PubMed

Howie, William O; McMullen, Patricia C

2006-01-01

Research literature supports the notion that maternal comfort should be considered a priority and that mothers should receive adequate information regarding any drug prior to receiving that drug. Some studies indicate that difficulties with breastfeeding may be related to the amount of the anesthetic or analgesic that is administered to the mother. Thus, it seems wise to administer the lowest possible dose to the mother in order to minimize the amount of drug (or metabolite) exposure to the nursing infant. Infant exposure can be further reduced if breastfeeding is avoided during the times when the mother receives high doses of anesthetics and analgesics. However, because relatively small amounts of the drug are excreted into the breast milk, some mothers may opt to continue nursing after weighing the benefits of breastfeeding against the potential risk to the infant. Others may choose to "pump and dump" breast milk while they receive anesthetic or analgesic agents. Any concerns in this regard should be discussed with the anesthesia provider, preferably prior to labor or to any surgeries while breastfeeding.

Discovery of a novel general anesthetic chemotype using high-throughput screening.

PubMed

McKinstry-Wu, Andrew R; Bu, Weiming; Rai, Ganesha; Lea, Wendy A; Weiser, Brian P; Liang, David F; Simeonov, Anton; Jadhav, Ajit; Maloney, David J; Eckenhoff, Roderic G

2015-02-01

The development of novel anesthetics has historically been a process of combined serendipity and empiricism, with most recent new anesthetics developed via modification of existing anesthetic structures. Using a novel high-throughput screen employing the fluorescent anesthetic 1-aminoanthracene and apoferritin as a surrogate for on-pathway anesthetic protein target(s), we screened a 350,000 compound library for competition with 1-aminoanthracene-apoferritin binding. Hit compounds meeting structural criteria had their binding affinities for apoferritin quantified with isothermal titration calorimetry and were tested for γ-aminobutyric acid type A receptor binding using a flunitrazepam binding assay. Chemotypes with a strong presence in the top 700 and exhibiting activity via isothermal titration calorimetry were selected for medicinal chemistry optimization including testing for anesthetic potency and toxicity in an in vivo Xenopus laevis tadpole assay. Compounds with low toxicity and high potency were tested for anesthetic potency in mice. From an initial chemical library of more than 350,000 compounds, we identified 2,600 compounds that potently inhibited 1-aminoanthracene binding to apoferritin. A subset of compounds chosen by structural criteria (700) was successfully reconfirmed using the initial assay. Based on a strong presence in both the initial and secondary screens the 6-phenylpyridazin-3(2H)-one chemotype was assessed for anesthetic activity in tadpoles. Medicinal chemistry efforts identified four compounds with high potency and low toxicity in tadpoles, two were found to be effective novel anesthetics in mice. The authors demonstrate the first use of a high-throughput screen to successfully identify a novel anesthetic chemotype and show mammalian anesthetic activity for members of that chemotype.

Discovery of a Novel General Anesthetic Chemotype Using High-throughput Screening

PubMed Central

McKinstry-Wu, Andrew R.; Bu, Weiming; Rai, Ganesha; Lea, Wendy A.; Weiser, Brian P.; Liang, David F.; Simeonov, Anton; Jadhav, Ajit; Maloney, David J.; Eckenhoff, Roderic G.

2014-01-01

Background The development of novel anesthetics has historically been a process of combined serendipity and empiricism, with most recent new anesthetics developed via modification of existing anesthetic structures. Methods Using a novel high-throughput screen employing the fluorescent anesthetic 1-aminoanthracene (1-AMA) and apoferritin as a surrogate for on-pathway anesthetic protein target(s), we screened a 350,000 compound library for competition with 1-AMA-apoferritin binding. Hit compounds meeting structural criteria had their binding affinities for apoferritin quantified with isothermal titration calorimetry and were tested for γ-aminobutyric acid type A-receptor binding using a flunitrazepam binding assay. Chemotypes with a strong presence in the top 700 and exhibiting activity via isothermal titration calorimetry were selected for medicinal chemistry optimization including testing for anesthetic potency and toxicity in an in vivo Xenopus laevis tadpole assay. Compounds with low toxicity and high potency were tested for anesthetic potency in mice. Results From an initial chemical library of over 350,000 compounds, we identified 2,600 compounds that potently inhibited 1-AMA binding to apoferritin. A subset of compounds chosen by structural criteria (700) was successfully reconfirmed using the initial assay. Based upon a strong presence in both the initial and secondary screens the 6-phenylpyridazin-3(2H)-one chemotype was assessed for anesthetic activity in tadpoles. Medicinal chemistry efforts identified four compounds with high potency and low toxicity in tadpoles, two were found to be effective novel anesthetics in mice. Conclusions We demonstrate the first use of a high-throughput screen to successfully identify a novel anesthetic chemotype and show mammalian anesthetic activity for members of that chemotype. PMID:25603205

Local Anesthetics: Review of Pharmacological Considerations

PubMed Central

Becker, Daniel E; Reed, Kenneth L

2012-01-01

Local anesthetics have an impressive history of efficacy and safety in medical and dental practice. Their use is so routine, and adverse effects are so infrequent, that providers may understandably overlook many of their pharmacotherapeutic principles. The purpose of this continuing education article is to provide a review and update of essential pharmacology for the various local anesthetic formulations in current use. Technical considerations will be addressed in a subsequent article. PMID:22822998

Inhibition of Microorganisms by Topical Anesthetics

PubMed Central

Kleinfeld, Jerome; Ellis, Philip P.

1967-01-01

The effect of various topical anesthetics and their preservatives on the growth of Pseudomonas aeruginosa, Staphyloccoccus albus, and Candida albicans was investigated. The topical anesthetics were proparacaine HCl, tetracaine HCl, cocaine HCl, and benoxinate HCl. The preservatives were chlorobutanol and butyl p-hydroxybenzoate. Proparacaine inhibited C. albicans but not P. aeruginosa or S. albus. All three test organisms were inhibited to varying degrees by tetracaine, benoxinate, cocaine, chlorobutanol, and butyl p-hydroxybenzoate. PMID:16349737

Effect of Inhalational Anesthetics on Acute Kidney Injury

PubMed

Miklić Bublić, Martina; Tonković, Dinko; Sakan, Sanja; Misir, Anita; Bandić Pavlović, Daniela

2016-09-01

Acute kidney injury (AKI) is a serious complication associated with increased morbidity and mortality. Total incidence of AKI in hospitalized patients is 1%-5%. As many as 30% of these patients develop AKI in the perioperative period, which is associated with anesthesia and surgery. Despite scientific advances and improved surgery techniques, as well as treatment in intensive care units, no significant decrease in AKI incidence has been achieved. To change this outcome, it is important to identify patients at risk of AKI and prevent its occurrence. Correct selection of anesthetic drugs during general anesthesia, adjusted to the individual needs of patients, also influences the overall outcome of treatment. Nowadays, inhalational anesthetics are not considered nephrotoxic. The more so, inhalational anesthetics have a strong and direct protective effect on many organs through preconditioning and postconditioning. New studies have shown that sevoflurane diminishes ischemia/ reperfusion kidney injury and has an anti-inflammatory effect, thus having the potential to reduce the occurrence of AKI. Given the incidence of AKI in the perioperative period, as well as new findings about anesthetics, the issue of anesthetic selection during general anesthesia might be of crucial importance for the final outcome of treatment.

Nocebo-induced hyperalgesia during local anesthetic injection.

PubMed

Varelmann, Dirk; Pancaro, Carlo; Cappiello, Eric C; Camann, William R

2010-03-01

Common practice during local anesthetic injection is to warn the patient using words such as: "You will feel a big bee sting; this is the worst part." Our hypothesis was that using gentler words for administration of the local anesthetic improves pain perception and patient comfort. One hundred forty healthy women at term gestation requesting neuraxial analgesia were randomized to either a "placebo" ("We are going to give you a local anesthetic that will numb the area and you will be comfortable during the procedure") or "nocebo" ("You are going to feel a big bee sting; this is the worst part of the procedure") group. Pain was assessed immediately after the local anesthetic skin injection using verbal analog scale scores of 0 to 10. Median verbal analog scale pain scores were lower when reassuring words were used compared with the harsher nocebo words (3 [2-4] vs 5 [3-6]; P < 0.001). Our data suggest that using gentler, more reassuring words improves the subjective experience during invasive procedures.

Sister chromatid exchanges induced by inhaled anesthetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

White,A.E.; Takehisa, S.; Eger II, E.I.

1970-05-01

There is sufficient evidence that anesthetics may cause cancer to justify a test of their carcinogenic potential. Baden et al., using the Ames test, a rapid and inexpensive genetic indicator of carcinogenicity, have shown that among currently used anesthetics fluorxene alone caused bacterial mutations. The authors used the sister chromatid exchange (SCE) technique, another rapid assay of mutagenic-carcinogenic potential. The frequency of sister chromatid exchanges in Chinese hamster ovary cells increases when the cell cultures are exposed to mutagen-carcinogens, particulary in the presence of a metabolic activating system. With this test system a one-hour exposure to 1 MAC nitrous oxide,more » diethyl ether, trichloroethylene, halothane, enflurane, isoflurane, methoxyflurane, or chloroform did not increase SCE values. Divinyl ether, fluroxene and ethyl vinyl ether increased SCE values in the same circumstances. Results of this study of mammalian cells suggest that no currently used anesthetic is a mutagen-carcinogen. The results also suggest that anesthetics containing a vinyl moiety may be mutagen-carcinogens.« less

Impact assessment of waste management options in Singapore.

PubMed

Tan, Reginald B H; Khoo, Hsien H

2006-03-01

This paper describes the application of life cycle assessment for evaluating various waste management options in Singapore, a small-island city state. The impact assessment method by SimaPro is carried out for comparing the potential environmental impacts of waste treatment options including landfilling, incineration, recycling, and composting. The inventory data include gases and leachate from landfills, air emissions and energy recovery from incinerators, energy (and emission) savings from recycling, composting gases, and transport pollution. The impact assessment results for climate change, acidification, and ecotoxicity show that the incineration of materials imposes considerable harm to both human health and the environment, especially for the burning of plastics, paper/cardboard, and ferrous metals. The results also show that, although some amount of energy can be derived from the incineration of wastes, these benefits are outweighed by the air pollution (heavy metals and dioxins/furans) that incinerators produce. For Singapore, landfill gases and leachate generate minimal environmental damage because of the nation's policy to landfill only 10% of the total disposed wastes. Land transportation and separation of waste materials also pose minimal environmental damage. However, sea transportation to the landfill could contribute significantly to acidification because of the emissions of sulfur oxides and nitrogen oxides from barges. The composting of horticultural wastes hardly imposes any environmental damage. Out of all the waste strategies, the recycling of wastes offers the best solution for environmental protection and improved human health for the nation. Significant emission savings can be realized through recycling.

Structural damage to periodontal tissues at varying rate of anesthetic injection.

PubMed

Sarapultseva, Maria; Sarapultsev, Alexey; Medvedeva, Svetlana; Danilova, Irina

2018-04-01

Incorrect administration of an anesthetic during local anesthesia is one of the most important causes of pain symptoms in patients scheduled for dental procedures. The current study assessed the severity of damage to periodontal tissue following different rates of anesthetic administration. The research was conducted on 50 outbred male rats with a body mass of 180-240 g. The anesthetic used was 1% articaine. The results showed that administration of the anesthetic at a rapid pace caused structural damage to the periodontal tissue. Further, signs of impaired microcirculation were noted at all rates of administration. Biochemical studies demonstrated changes in the level of glucose and enzymes with the rapid introduction of the anesthetic, indicating severe systemic stress response of the body. Injection of local anesthetic at any rate of introduction induces vascular congestion in the microcirculatory bloodstream and exudative reactions. Rapid introduction of an anesthetic causes progression of structural changes in the gingival tissue.

Thermal and chemical remediation of mixed waste

DOEpatents

Nelson, P.A.; Swift, W.M.

1994-08-09

A process and system for treating organic waste materials without venting gaseous emissions to the atmosphere. A fluidized bed including lime particles is operated at a temperature of at least 500 C by blowing gas having 20%/70% oxygen upwardly through the bed particles at a rate sufficient to fluidize same. A toxic organic waste material is fed into the fluidized bed where the organic waste material reacts with the lime forming CaCO[sub 3]. The off gases are filtered and cooled to condense water which is separated. A portion of the calcium carbonate formed during operation of the fluidized bed is replaced with lime particles. The off gases from the fluidized bed after drying are recirculated until the toxic organic waste material in the bed is destroyed. 3 figs.

Thermal and chemical remediation of mixed waste

DOEpatents

Nelson, Paul A.; Swift, William M.

1994-01-01

A process and system for treating organic waste materials without venting gaseous emissions to the atmosphere. A fluidized bed including lime particles is operated at a temperature of at least 500.degree. C. by blowing gas having 20%/70% oxygen upwardly through the bed particles at a rate sufficient to fluidize same. A toxic organic waste material is fed into the fluidized bed where the organic waste material reacts with the lime forming CaCO.sub.3. The off gases are filtered and cooled to condense water which is separated. A portion of the calcium carbonate formed during operation of the fluidized bed is replaced with lime particles. The off gases from the fluidized bed after drying are recirculated until the toxic organic waste material in the bed is destroyed.

Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons.

PubMed

Hajizadeh, Yaghoub; Onwudili, Jude A; Williams, Paul T

2011-06-01

The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275°C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 μg I-TEQ kg(-1) toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 μg I-TEQ kg(-1) in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases. Copyright © 2011 Elsevier Ltd. All rights reserved.

CLEANING OF FLUE GASES FROM WASTE COMBUSTORS

EPA Science Inventory

The paper addresses flue gas cleaning processes currently used commercially in waste combustion facilities. It also discusses the operating concepts of dry, semi-dry, and wet processes and their effectiveness in controlling various pollutants. Air pollutants from the combustion o...

An investigation of the presence of methane and other gases at the Uzundere-Izmir solid waste disposal site, Izmir, Turkey.

PubMed

Onargan, T; Kucuk, K; Polat, M

2003-01-01

Izmir is a large metropolitan city with a population of 3,114,860. The city consists of 27 townships, each township has a population of not less than 10,000 inhabitants. The two major solid waste disposal sites are in the townships of Uzundere and Harmandali. The amount of solid waste that is disposed at each of these sites is about 800 and 1800 t/day, respectively. In Uzundere, compost is produced from the organic fraction of urban solid wastes while the residual material is deposited at a disposal site with a remaining capacity of 700,000 m(3) as of 2001. Gas monitoring and measurements were carried out at the disposal site in Uzundere. For this purpose, nine sampling wells were drilled on selected locations. Each well was furnished with perforated metal pipes suitable for gas monitoring and measurements. The following gases were monitored: O(2), CH(4), CO, CO(2), and H(2)S. The most important finding was that the concentrations of CH(4) in the wells ranged from 7 to 57%. Dilution of the CH(4) by O(2) down to the LEL levels (5-15%) is always possible and poses a continuing risk at the site. Furthermore, the levels of O(2) require that access to the site be limited to only authorized personnel.

A Review of Anesthetic Effects on Renal Function: Potential Organ Protection.

PubMed

Motayagheni, Negar; Phan, Sheshanna; Eshraghi, Crystal; Nozari, Ala; Atala, Anthony

2017-01-01

Renal protection is a critical concept for anesthesiologists, nephrologists, and urologists, since anesthesia and renal function are highly interconnected and can potentially interfere with one another. Therefore, a comprehensive understanding of anesthetic drugs and their effects on renal function remains fundamental to the success of renal surgeries, especially transplant procedures. Some experimental studies have shown that some anesthetics provide protection against renal ischemia/reperfusion (IR) injury, but there is limited clinical evidence. The effects of anesthetic drugs on renal failure are particularly important in the context of kidney transplantation, since the conditions of preservation following removal profoundly influence the recovery of organ function. Currently, preservation procedures are typically based on the usage of a cold-storage solution. Some anesthetic drugs induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. A more thorough understanding of anesthetic effects on renal function can present a novel approach for developing organ-protective strategies. The aim of this review is to discuss the effects of different anesthetic drugs on renal function, with particular focus on IR injury. Many studies have demonstrated the organ-protective effects of some anesthetic drugs, specifically propofol, which indicate the potential of some anesthetics to introduce novel organ protective targets. This is not surprising, since lipid emulsions are major components of propofol, which accumulating data show provide organ protective effects against IR injury. Key Messages: Thorough understanding of the interaction between anesthetic drugs and renal function remains fundamental to the delivery of safe perioperative care and to optimizing outcomes after renal surgeries, particularly transplant procedures. Anesthetics can be repurposed for organ protection with more information about their effects, especially during transplant procedures. Here

Molecular genetic analysis of volatile-anesthetic action.

PubMed Central

Keil, R L; Wolfe, D; Reiner, T; Peterson, C J; Riley, J L

1996-01-01

The mechanism(s) and site(s) of action of volatile inhaled anesthetics are unknown in spite of the clinical use of these agents for more than 150 years. In the present study, the model eukaryote Saccharomyces cerevisiae was used to investigate the action of anesthetic agents because of its powerful molecular genetics. It was found that growth of yeast cells is inhibited by the five common volatile anesthetics tested (isoflurane, halothane, enflurane, sevoflurane, and methoxyflurane). Growth inhibition by the agents is relatively rapid and reversible. The potency of these compounds as yeast growth inhibitors directly correlates with their lipophilicity as is predicted by the Meyer-Overton relationship, which directly correlates anesthetic potency of agents and their lipophilicity. The effects of isoflurane on yeast cells were characterized in the most detail. Yeast cells survive at least 48 h in a concentration of isoflurane that inhibits colony formation. Mutants resistant to the growth-inhibitory effects of isoflurane are readily selected. The gene identified by one of these mutations, zzz4-1, has been cloned and characterized. The predicted ZZZ4 gene product has extensive homology to phospholipase A2-activating protein, a GO effector protein of mice. Both zzz4-1 and a deletion of ZZZ4 confer resistance to all five of the agents tested, suggesting that signal transduction may be involved in the response of these cells to volatile anesthetics. PMID:8668160

Randomized clinical trial of local anesthetic versus a combination of local anesthetic with self-hypnosis in the management of pediatric procedure-related pain.

PubMed

Liossi, Christina; White, Paul; Hatira, Popi

2006-05-01

A prospective controlled trial was conducted to compare the efficacy of an analgesic cream (eutectic mixture of local anesthetics, or EMLA) with a combination of EMLA with hypnosis in the relief of lumbar puncture-induced pain and anxiety in 45 pediatric cancer patients (age 6-16 years). The study also explored whether young patients can be taught and can use hypnosis independently as well as whether the therapeutic benefit depends on hypnotizability. Patients were randomized to 1 of 3 groups: local anesthetic, local anesthetic plus hypnosis, and local anesthetic plus attention. Results confirmed that patients in the local anesthetic plus hypnosis group reported less anticipatory anxiety and less procedure-related pain and anxiety and that they were rated as demonstrating less behavioral distress during the procedure. The level of hypnotizability was significantly associated with the magnitude of treatment benefit, and this benefit was maintained when patients used hypnosis independently. 2006 APA, all rights reserved

Anesthetic Requirement is Increased in Redheads

PubMed Central

Liem, Edwin B.; Lin, Chun–Ming; Suleman, Mohammad–Irfan; Doufas, Anthony G.; Gregg, Ronald G.; Veauthier, Jacqueline M.; Loyd, Gary

2005-01-01

Background: Age and body temperature alter inhalational anesthetic requirement; however, no human genotype is associated with inhalational anesthetic requirement. There is an anecdotal impression that anesthetic requirement is increased in redheads. Furthermore, red hair results from distinct mutations of the melanocortin-1 receptor. We thus tested the hypothesis that the requirement for the volatile anesthetic desflurane is greater in natural redhead than in dark-haired women. Methods: We studied healthy women with bright red (n=10) or dark (n=10) hair. Blood was sampled for subsequent analyses of melanocortin-1 receptor alleles. Anesthesia was induced with sevoflurane and maintained with desflurane randomly set at an end-tidal concentration between 5.5 and 7.5%. After an equilibration period, a noxious electrical stimulation (100 Hz, 70 mA) was transmitted through bilateral intradermal needles. If the volunteer moved in response to stimulation, desflurane was increased by 0.5%; otherwise it was decreased by 0.5%. This was continued until volunteers “crossed-over” from movement to non-movement (or vice versa) four times. Individual logistic regression curves were used to determine desflurane requirement (P50). Desflurane requirements in the two groups were compared using Mann-Whitney nonparametric two-sample test; P < 0.05 was considered statistically significant. Results: The desflurane requirement in redheads (6.2 volume-percent [95% CI, 5.9 - 6.5]) was significantly greater than in dark-haired women (5.2 volume-percent [4.9 – 5.5], P = 0.0004). Nine of 10 redheads were either homozygous or compound heterozygotes for mutations on the melanocortin-1 receptor gene. Conclusions: Red hair appears to be a distinct phenotype linked to anesthetic requirement in humans that can also be traced to a specific genotype. PMID:15277908

Comparative efficacy of 16 anesthetic chemicals on rainbow trout

USGS Publications Warehouse

Gilderhus, P.A.; Marking, L.L.

1987-01-01

Presently there are no legally registered fish anesthetics that allow for the release of fish or use of the fish for food soon after they have been anesthetized. MS-222 (tricaine), the only anesthetic registered for use on fish in the United States, cannot be used within 21 d of harvesting the fish for food. As the start in a search for an anesthetic that can be used with little or no withdrawal period, we tested the efficacy of 16 chemicals as anesthetics on rainbow trout Salmo gairdneri. Efficacy was defined by the fish (1) becoming handleable (quiet enough to be manipulated and handled readily) in 3 min or less, (2) recovering in 10 min or less, and (3) showing no mortality after 15 min in the anesthetic solution. Four chemicals--MS-222, quinaldine sulfate, benzocaine, and 2-phenoxyethanol--met these criteria for efficacy. Chemicals that yielded excessive induction or recovery times or caused excessive mortality were methylpentynol, chlorobutanol, etomidate, metomidate, Piscaine, propanidid, carbon dioxide, nicotine, salt, Halothane, Metofane, and Biotal. Because carbon dioxide leaves no residues and requires no withdrawal period, it may be an acceptable alternative for fishery workers who can tolerate somewhat shallower anesthesia and longer induction and recovery times.

Clinical concentrations of chemically diverse general anesthetics minimally affect lipid bilayer properties.

PubMed

Herold, Karl F; Sanford, R Lea; Lee, William; Andersen, Olaf S; Hemmings, Hugh C

2017-03-21

General anesthetics have revolutionized medicine by facilitating invasive procedures, and have thus become essential drugs. However, detailed understanding of their molecular mechanisms remains elusive. A mechanism proposed over a century ago involving unspecified interactions with the lipid bilayer known as the unitary lipid-based hypothesis of anesthetic action, has been challenged by evidence for direct anesthetic interactions with a range of proteins, including transmembrane ion channels. Anesthetic concentrations in the membrane are high (10-100 mM), however, and there is no experimental evidence ruling out a role for the lipid bilayer in their ion channel effects. A recent hypothesis proposes that anesthetic-induced changes in ion channel function result from changes in bilayer lateral pressure that arise from partitioning of anesthetics into the bilayer. We examined the effects of a broad range of chemically diverse general anesthetics and related nonanesthetics on lipid bilayer properties using an established fluorescence assay that senses drug-induced changes in lipid bilayer properties. None of the compounds tested altered bilayer properties sufficiently to produce meaningful changes in ion channel function at clinically relevant concentrations. Even supra-anesthetic concentrations caused minimal bilayer effects, although much higher (toxic) concentrations of certain anesthetic agents did alter lipid bilayer properties. We conclude that general anesthetics have minimal effects on bilayer properties at clinically relevant concentrations, indicating that anesthetic effects on ion channel function are not bilayer-mediated but rather involve direct protein interactions.

Clinical concentrations of chemically diverse general anesthetics minimally affect lipid bilayer properties

PubMed Central

Herold, Karl F.; Sanford, R. Lea; Lee, William; Andersen, Olaf S.; Hemmings, Hugh C.

2017-01-01

General anesthetics have revolutionized medicine by facilitating invasive procedures, and have thus become essential drugs. However, detailed understanding of their molecular mechanisms remains elusive. A mechanism proposed over a century ago involving unspecified interactions with the lipid bilayer known as the unitary lipid-based hypothesis of anesthetic action, has been challenged by evidence for direct anesthetic interactions with a range of proteins, including transmembrane ion channels. Anesthetic concentrations in the membrane are high (10–100 mM), however, and there is no experimental evidence ruling out a role for the lipid bilayer in their ion channel effects. A recent hypothesis proposes that anesthetic-induced changes in ion channel function result from changes in bilayer lateral pressure that arise from partitioning of anesthetics into the bilayer. We examined the effects of a broad range of chemically diverse general anesthetics and related nonanesthetics on lipid bilayer properties using an established fluorescence assay that senses drug-induced changes in lipid bilayer properties. None of the compounds tested altered bilayer properties sufficiently to produce meaningful changes in ion channel function at clinically relevant concentrations. Even supra-anesthetic concentrations caused minimal bilayer effects, although much higher (toxic) concentrations of certain anesthetic agents did alter lipid bilayer properties. We conclude that general anesthetics have minimal effects on bilayer properties at clinically relevant concentrations, indicating that anesthetic effects on ion channel function are not bilayer-mediated but rather involve direct protein interactions. PMID:28265069

Detomidine reduces isoflurane anesthetic requirement (MAC) in horses.

PubMed

Steffey, Eugene P; Pascoe, Peter J

2002-10-01

To quantitate the dose- and time-related magnitude of the anesthetic sparing effect of, and selected physiological responses to detomidine during isoflurane anesthesia in horses. Randomized cross-over study. Three, healthy, young adult horses weighing 485 ± 14 kg. Horses were anesthetized on two occasions to determine the minimum alveolar concentration (MAC) of isoflurane in O 2 and then to measure the anesthetic sparing effect (time-related MAC reduction) following IV detomidine (0.03 and 0.06 mg kg -1 ). Selected common measures of cardiopulmonary function, blood glucose and urinary output were also recorded. Isoflurane MAC was 1.44 ± 0.07% (mean ± SEM). This was reduced by 42.8 ± 5.4% and 44.8 ± 3.0% at 83 ± 23 and 125 ± 36 minutes, respectively, following 0.03 and 0.06 mg kg -1 , detomidine. The MAC reduction was detomidine dose- and time-dependent. There was a tendency for mild cardiovascular and respiratory depression, especially following the higher detomidine dose. Detomidine increased both blood glucose and urine flow; the magnitude of these changes was time- and dose-dependent CONCLUSIONS: Detomidine reduces anesthetic requirement for isoflurane and increases blood glucose concentration and urine flow in horses. These changes were dose- and time-related. The results imply potent anesthetic sparing actions by detomidine. The detomidine-related increased urine flow should be considered in designing anesthetic protocols for individual horses. Copyright © 2002 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

Intravenous sub-anesthetic ketamine for perioperative analgesia

PubMed Central

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. PMID:27275042

46 CFR 147.105 - Anesthetics, drugs, and medicines.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Anesthetics, drugs, and medicines. 147.105 Section 147.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS..., drugs, and medicines. Anesthetics, drugs, and medicines must be stowed and dispensed in accordance with...

46 CFR 147.105 - Anesthetics, drugs, and medicines.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Anesthetics, drugs, and medicines. 147.105 Section 147.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS..., drugs, and medicines. Anesthetics, drugs, and medicines must be stowed and dispensed in accordance with...

46 CFR 147.105 - Anesthetics, drugs, and medicines.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Anesthetics, drugs, and medicines. 147.105 Section 147.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS..., drugs, and medicines. Anesthetics, drugs, and medicines must be stowed and dispensed in accordance with...

46 CFR 147.105 - Anesthetics, drugs, and medicines.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Anesthetics, drugs, and medicines. 147.105 Section 147.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS..., drugs, and medicines. Anesthetics, drugs, and medicines must be stowed and dispensed in accordance with...

46 CFR 147.105 - Anesthetics, drugs, and medicines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Anesthetics, drugs, and medicines. 147.105 Section 147.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS..., drugs, and medicines. Anesthetics, drugs, and medicines must be stowed and dispensed in accordance with...

Insights into the Nature of Anesthetic-Protein Interactions: An ONIOM Study.

PubMed

Qiu, Ling; Lin, Jianguo; Bertaccini, Edward J

2015-10-08

Anesthetics have been employed widely to relieve surgical suffering, but their mechanism of action is not yet clear. For over a century, the mechanism of anesthesia was previously thought to be via lipid bilayer interactions. In the present work, a rigorous three-layer ONIOM(M06-2X/6-31+G*:PM6:AMBER) method was utilized to investigate the nature of interactions between several anesthetics and actual protein binding sites. According to the calculated structural features, interaction energies, atomic charges, and electrostatic potential surfaces, the amphiphilic nature of anesthetic-protein interactions was demonstrated for both inhalational and injectable anesthetics. The existence of hydrogen and halogen bonding interactions between anesthetics and proteins was clearly identified, and these interactions served to assist ligand recognition and binding by the protein. Within all complexes of inhalational or injectable anesthetics, the polarization effects play a dominant role over the steric effects and induce a significant asymmetry in the otherwise symmetric atomic charge distributions of the free ligands in vacuo. This study provides new insight into the mechanism of action of general anesthetics in a more rigorous way than previously described. Future rational design of safer anesthetics for an aging and more physiologically vulnerable population will be predicated on this greater understanding of such specific interactions.

Anesthetic depth and long-term survival: an update.

PubMed

Leslie, Kate; Short, Timothy G

2016-02-01

The purpose of this paper is to review the current evidence relating anesthetic depth to long-term survival after surgery. Using PubMed as the principal source, this review included published studies in all languages comparing mortality in patients with low- and high-processed electro-encephalo-graphic index values. All published studies used the bispectral index (BIS) monitor to measure anesthetic depth. The majority of the published observational studies were post hoc analyses of studies undertaken for other purposes. Most of these studies report a statistically significant association between deep general anesthesia (i.e., BIS values < 45) and death. Some studies also suggest an association between deep general anesthesia and myocardial infarction or postoperative cognitive decline. The combination of low BIS values and low delivered anesthetic concentrations (thus defining increased anesthetic sensitivity) may identify patients at particularly high risk. One of the three available randomized controlled trials reports worse outcomes in the BIS = 50 group compared with the BIS > 80 group, and two report no difference in mortality between the BIS = 35 and BIS = 50-55 groups. The available evidence on anesthetic depth and long-term survival is inconclusive. Randomized controlled trials with carefully controlled arterial blood pressure are required.

Study on the impact of industrial flue gases on the PCDD/Fs congener profile in ambient air.

PubMed

Węgiel, Małgorzata; Chrząszcz, Ryszard; Maślanka, Anna; Grochowalski, Adam

2014-11-01

The aim of this study was to examine the impact of emissions from combustion processes from sinter, medical, waste and sewage waste incineration plants on the PCDD and PCDF congener profile in ambient air in Krakow (city in Poland). The subject matter of the study were air samples from the outskirts and the city center. It was found that in flue gases from industrial sources and in ambient air the share of PCDF congeners in relation to the total content of PCDD/Fs was higher than the share of PCDDs. However, in air samples collected in the city center, this relationship was reversed. The PCDD congener profiles in flue gases and in air samples are comparable. However, in the samples from the city centre, the share of OCDD is significantly higher and amounts to about 80%. The PCDF congener shares show higher spatial diversity, although in all the analyzed air samples, ODCF and 1,2,3,4,6,7,8 HpCDF dominated. Analyzing the share of congeners in regard to the sum of PCDDs/Fs a mutual resemblance of air from the suburbs, exhaust gases from the sinter ore and sewage sludge incinerator plant was observed. The study showed a similarity between the profile of congeners in air from the city centre and exhaust gases from the medical waste incinerator. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pharmacological properties of various anesthetic protocols in 10-day-old neonatal rats.

PubMed

Tsukamoto, Atsushi; Konishi, Yui; Kawakami, Takako; Koibuchi, Chiharu; Sato, Reiichiro; Kanai, Eiichi; Inomata, Tomo

2017-10-30

In general, the anesthesia in neonates involves high risk. Although hypothermic anesthesia is recommended in rats up to the age of 7 days, neonatal anesthesia for later periods has not been standardized. The present study investigated the pharmacological properties of conventional anesthetic protocols in 10-day-old SD rats. The rats were anesthetized with four anesthetics: a combination of ketamine and xylazine (K/X); a combination of medetomidine, midazolam, and butorphanol (M/M/B); isoflurane; and sevoflurane. Anesthetic depth was scored by reflex response to noxious stimuli. Induction and recovery times were recorded. Vital signs and mortality rate were evaluated for safety assessment. All rats died after administration of K/X at a dose of 60/6 mg/kg, whereas K/X at 40/4 mg/kg resulted in insufficient anesthetic depth, indicating inappropriate for neonatal anesthesia. Although M/M/B at the adult rat dose (0.15/2/2.5 mg/kg) did not provide surgical anesthetic depth, the mouse dose (0.3/4/5 mg/kg) showed sufficient anesthetic depth with relatively stable vital signs. Isoflurane required a long induction period, and caused remarkable respiratory depression and hypothermia, resulted in a 25% mortality rate. In contrast, sevoflurane provided consistent surgical anesthetic depth with rapid induction. Although respiratory rate decrease was markedly observed, all rats survived. Among the anesthetic protocols investigated in the present study, sevoflurane and M/M/B at the mouse dose were recommended for the neonatal anesthesia. Compared with adult rats, the required dose of both anesthetics in neonates was higher, possibly associated with their lower anesthetic sensitivity.

[Anesthetic management of four patients with Fournier syndrome].

PubMed

Sato, Rui; Tomioka, Toshiya; Orii, Ryo; Yamada, Yoshitsugu

2008-03-01

We experienced anesthetic managements of four patients with Fournier syndrome. In the anesthetic management of the patients with Fournier syndrome the following three points should be kept in mind; (a) the necessity of careful preoperative examination, (b) the better anesthesia, and (c) the careful postoperative care.

Variability in anesthetic considerations for arteriovenous fistula creation.

PubMed

Siracuse, Jeffrey J; Gill, Heather L; Parrack, Inkyong; Huang, Zhen S; Schneider, Darren B; Connolly, Peter H; Meltzer, Andrew J

2014-01-01

Anesthetic options for arteriovenous fistula (AVF) creation include regional anesthesia (RA), general anesthesia (GA) and local anesthetic for select cases. In addition to the benefits of avoiding GA in high-risk patients, recent studies suggest that RA may increase perioperative venous dilation and improve maturation. Our objective was to assess perioperative outcomes of AVF creation with respect to anesthetic modality and identify patient-level factors associated with variation in contemporary anesthetic selection. National Surgical Quality Improvement Project (NSQIP) data (2007-2010) were accessed to identify patients undergoing AVF creation. Univariate analysis and multivariate logistic regression were performed to assess the relationships among patient characteristics, anesthesia modality and outcome. Of 1,540 patients undergoing new upper extremity AVF creation, 52% were male and 81% were younger than 75 years. Anesthesia distribution was GA in 85.2%, local/monitored anesthetic care (MAC) in 2.9% and RA in 11.9% of cases. By multivariate analysis, independent predictors of RA were dyspnea at rest (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.1-4.9), age >75 (HR 1.6, 95% CI 1.1-2.3) and teaching hospital status as indicated by housestaff involvement (HR 3.7, 95% CI 2.5-5.5). RA was associated with higher total operative time, duration of anesthesia, length of time in operating room and duration of anesthesia start until surgery start (p<0.01). There were no differences between perioperative complications or mortality among anesthetic modalities, although all deaths occurred in the GA group. Despite recent reports highlighting potential benefits of RA for AVF creation, GA was surprisingly used in the vast majority of cases in the United States. The only comorbidities associated with preferential RA use were advanced age and dyspnea at rest. Practice environment may influence anesthetic selection for these cases, as a nonteaching environment was

[Treatment of organic waste gas by adsorption rotor].

PubMed

Zhu, Run-Ye; Zheng, Liang-Wei; Mao, Yu-Bo; Wang, Jia-De

2013-12-01

The adsorption rotor is applicable to treating organic waste gases with low concentration and high air volume. The performance of adsorption rotor for purifying organic waste gases was investigated in this paper. Toluene was selected as the simulative gaseous pollutant and the adsorption rotor was packed with honeycomb modified 13X molecular sieves (M-13X). Experimental results of the fixed adsorption and the rotor adsorption were analyzed and compared. The results indicated that some information on the fixed adsorption was useful for the rotor adsorption. Integrating the characteristics of the adsorbents, waste gases and the structures of the rotor adsorption, the formulas on optimal rotor speed and cycle removal efficiency of the adsorption rotor were deduced, based on the mass and heat balances of the adsorbing process. The numerical results were in good agreement with the experimental data, which meant that the formulas on optimal rotor speed and cycle removal efficiency could be effectively applied in design and operation of the adsorption rotor.

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

PubMed Central

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

Anesthetic effects on fictive locomotion in the rat isolated spinal cord

PubMed Central

Jinks, Steven L.; Andrada, Jason; Satter, Omar

2011-01-01

General anesthetic mechanisms are poorly understood. Anesthetic immobilizing effects occur in the spinal ventral horn. However, a detailed analysis of anesthetic effects on ventral motor networks is lacking. We delivered isoflurane, desflurane, or propofol during NMDA/5-HT-induced, or noxious tail stimulus-evoked, fictive locomotion in neonatal rat isolated spinal cords. Anesthetics changed the frequency, amplitude, and regularity of fictive locomotion with little effect on phase-lag. Isoflurane abolished pharmacologically-induced vs noxious stimulus-induced motor output at similar concentrations. Propofol abolished pharmacologically-induced fictive locomotion via a GABAA-receptor mechanism. Anesthetic effects on pharmacologically-elicted fictive locomotion appear clinically-relevant, and support a ventral horn immobilizing effect on locomotor rhythm generation. PMID:21817927

Postoperative environmental anesthetic vapour concentrations following removal of the airway device in the operating room versus the postanesthesia care unit.

PubMed

Cheung, Sara K; Özelsel, Timur; Rashiq, Saifee; Tsui, Ban C

2016-09-01

This study was designed to compare waste anesthetic gas (WAG) concentrations within patients' breathing zones after removal of the patient's airway device in the postanesthesia care unit (PACU) vs in the operating room (OR). Following Research Ethics Board approval and patient consent, we recruited patients undergoing surgery who received volatile anesthesia via an endotracheal tube or supraglottic airway. Patients had their airway device removed in the OR or in the PACU depending on the attending anesthesiologist's preference. Upon the patient's arrival in the PACU, concentrations of exhaled sevoflurane and desflurane were measured at their breathing zone (i.e., 15 cm from the patient's mouth and nose) using a single-beam infrared spectrophotometer. Seventy patients were recruited during the five-month study period. The median [interquartile range] WAG levels in the patients' breathing zones were higher when their airway devices were removed in the PACU vs in the OR. The WAG levels for sevoflurane were 0.7 [0.4-1.1] parts per million (ppm) vs 0.5 [0.4-0.7] ppm, respectively; median difference, 0.3; 95% confidence interval (CI), 0.1 to 0.6; P = 0.04. The WAG levels for desflurane were 2.4 [1.2-3.4] ppm vs 4.1 [2.5-5.2] ppm, respectively; median difference, 1.5; 95% CI, 0.3 to 2.7; P = 0.04. After a volatile-based anesthetic, our results suggest that removal of the airway device in the PACU vs in the OR increases the amount of waste anesthetic gas in a patient's breathing zone and thus potentially in the PACU nurse's working zone.

Effects of surgery and anesthetic choice on immunosuppression and cancer recurrence.

PubMed

Kim, Ryungsa

2018-01-18

The relationship between surgery and anesthetic-induced immunosuppression and cancer recurrence remains unresolved. Surgery and anesthesia stimulate the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) to cause immunosuppression through several tumor-derived soluble factors. The potential impact of surgery and anesthesia on cancer recurrence was reviewed to provide guidance for cancer surgical treatment. PubMed was searched up to December 31, 2016 using search terms such as, "anesthetic technique and cancer recurrence," "regional anesthesia and cancer recurrence," "local anesthesia and cancer recurrence," "anesthetic technique and immunosuppression," and "anesthetic technique and oncologic surgery." Surgery-induced stress responses and surgical manipulation enhance tumor metastasis via release of angiogenic factors and suppression of natural killer (NK) cells and cell-mediated immunity. Intravenous agents such as ketamine and thiopental suppress NK cell activity, whereas propofol does not. Ketamine induces T-lymphocyte apoptosis but midazolam does not affect cytotoxic T-lymphocytes. Volatile anesthetics suppress NK cell activity, induce T-lymphocyte apoptosis, and enhance angiogenesis through hypoxia inducible factor-1α (HIF-1α) activity. Opioids suppress NK cell activity and increase regulatory T cells. Local anesthetics such as lidocaine increase NK cell activity. Anesthetics such as propofol and locoregional anesthesia, which decrease surgery-induced neuroendocrine responses through HPA-axis and SNS suppression, may cause less immunosuppression and recurrence of certain types of cancer compared to volatile anesthetics and opioids.

Topical ocular anesthetic abuse among Iranian welders: time for action.

PubMed

Sharifi, Ali; Sharifi, Hamid; Karamouzian, Mohammad; Mokhtari, Mahmoud; Esmaeili, Hamidreza Hosein; Nejad, Afshin Sarafi; Rahmatian, Mohammad

2013-01-01

The purpose of this study is to estimate the prevalence of topical ocular anesthetic abuse among welders in Iran and suggest public health solutions for this issue. In this cross-sectional study, 390 welders were randomly recruited and queried on the use of anesthetic drops. A questionnaire was administered through structured one-on-one interviews conducted by the first author. A total of 314 welders (80.5%) declared that they had used topical anesthetics at least once during their working lives. Almost 90% of them stated a preference for self-treatment over seeking help from a physician due to cultural and financial reasons. The most commonly used topical anesthetic was tetracaine. Most of the subjects (97.4%) had obtained the drugs from pharmacies without a prescription. The prevalence of topical ocular anesthetic abuse among welders in Iran is alarmingly high and may partially be due to cultural issues. Although most physicians are aware that topical anesthetics should only be used as a diagnostic tool, there is a crucial need to re-emphasize the ocular risks associated with chronic use of these medications. Educational programs for both physicians and the public are necessary to address the problem.

21 CFR 346.10 - Local anesthetic active ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Local anesthetic active ingredients. 346.10... (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.10 Local anesthetic active ingredients. The active ingredient of the product consists of any of...

21 CFR 346.10 - Local anesthetic active ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Local anesthetic active ingredients. 346.10... (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.10 Local anesthetic active ingredients. The active ingredient of the product consists of any of...

21 CFR 346.10 - Local anesthetic active ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Local anesthetic active ingredients. 346.10... (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.10 Local anesthetic active ingredients. The active ingredient of the product consists of any of...

21 CFR 346.10 - Local anesthetic active ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Local anesthetic active ingredients. 346.10 Section 346.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 346.10 Local anesthetic active ingredients. The active ingredient of the product consists of any of...

21 CFR 346.10 - Local anesthetic active ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Local anesthetic active ingredients. 346.10 Section 346.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 346.10 Local anesthetic active ingredients. The active ingredient of the product consists of any of...

Central waste processing system

NASA Technical Reports Server (NTRS)

Kester, F. L.

1973-01-01

A new concept for processing spacecraft type wastes has been evaluated. The feasibility of reacting various waste materials with steam at temperatures of 538 - 760 C in both a continuous and batch reactor with residence times from 3 to 60 seconds has been established. Essentially complete gasification is achieved. Product gases are primarily hydrogen, carbon dioxide, methane, and carbon monoxide. Water soluble synthetic wastes are readily processed in a continuous tubular reactor at concentrations up to 20 weight percent. The batch reactor is able to process wet and dry wastes at steam to waste weight ratios from 2 to 20. Feces, urine, and synthetic wastes have been successfully processed in the batch reactor.

Surgical site infection after colorectal surgery according to the main anesthetic agent: a retrospective comparison between volatile anesthetics and propofol.

PubMed

Koo, Bon-Wook; Sim, Jun-Bo; Shin, Hyun-Jung; Kim, Duck-Woo; Kang, Sung-Bum; Do, Sang-Hwan; Na, Hyo-Seok

2016-08-01

Anesthetic agents used for general anesthesia are emerging possible influential factors for surgical site infection (SSI). In this retrospective study, we evaluated the incidence of SSI after colorectal surgery according to the main anesthetic agents: volatile anesthetics vs. propofol. A total 1,934 adult patients, who underwent elective colorectal surgery under general anesthesia between January 2011 and December 2013, were surveyed to evaluate the incidence of SSI: 1,519 using volatile anesthetics and 415 using propofol for main anesthetic agents. Patient, surgery, and anesthesia-related factors were investigated from all patients. Propensity-score matching was performed to reduce the risk of confounding and produced 390 patients in each group. Within the propensity-score matched groups, the incidence of SSI was higher in the volatile group compared with the propofol group (10 [2.6%] vs. 2 [0.5%], OR = 5.0 [95% CI = 1.1-2.8]). C-reactive protein was higher in the volatile group than in the propofol group (8.4 ± 5.6 vs. 7.1 ± 5.3 mg/dl, P = 0.001), and postoperative white blood cells count was higher in the volatile group than in the propofol group (9.2 ± 3.2 × 10(3)/µl vs. 8.6 ± 3.4 × 10(3)/µl, P = 0.041). The results of this study suggest that intravenous anesthesia may have beneficial effects for reducing SSI in colorectal surgery compared to volatile anesthesia.

Studies on potential emission of hazardous gases due to uncontrolled open-air burning of waste vehicle tyres and their possible impacts on the environment

NASA Astrophysics Data System (ADS)

Shakya, Pawan R.; Shrestha, Pratima; Tamrakar, Chirika S.; Bhattarai, Pradeep K.

Uncontrolled open-air burning of waste vehicle tyres causing environmental pollution has become a popular practice in Nepal despite official ban considering the environment and public health hazards. In this study, an experimental model was set up in a laboratory scale in an attempt to understand the potential emission of hazardous gases such as CO, SO 2 and NO 2 due to such activities in Kathmandu Valley and their possible impacts on the environment. For this purpose, four types of tyre were collected representing two from passenger car and two from motorbike category. The emission level of CO in the tyre smoke was measured with a CO gas detector tube while SO 2 and NO 2 were determined by UV-visible spectrophotometer. Among the three types of the gases analyzed, SO 2 was emitted in significantly high levels by all the representative tyre samples. The emission levels of CO, SO 2 and NO 2 ranged from 21to 49, 102to 820 and 3to 9 μg g -1, respectively. Results revealed that the emission levels also varied with the tyre types and qualities. The potential emission of the hazardous gases per representative scrap tyre mass was also estimated. Results indicate that the gaseous pollutants due to the tyre fires could make a significant contribution for deterioration of the environmental condition of the Valley or elsewhere.

Rapid eye movement sleep debt accrues in mice exposed to volatile anesthetics

PubMed Central

Pick, Jeremy; Chen, Yihan; Moore, Jason T.; Sun, Yi; Wyner, Abraham J.; Friedman, Eliot B.; Kelz, Max B.

2011-01-01

Background General anesthesia has been likened to a state in which anesthetized subjects are locked out of access to both rapid eye movement (REM) sleep and wakefulness. Were this true for all anesthetics, one might expect a significant REM rebound following anesthetic exposure. However, for the intravenous anesthetic propofol, studies demonstrate that no sleep debt accrues. Moreover, pre-existing sleep debts dissipate during propofol anesthesia. To determine whether these effects are specific to propofol or are typical of volatile anesthetics we tested the hypothesis that REM sleep debt would accrue in rodents anesthetized with volatile anesthetics. Methods Electroencephalographic and electromyographic electrodes were implanted in 10 mice. After 9–11 days of recovery and habituation to a 12h:12h light:dark cycle, baseline states of wakefulness, non-rapid eye movement sleep, and REM sleep were recorded in mice exposed to 6 hours of an oxygen control and on separate days to 6 hours of isoflurane, sevoflurane, or halothane in oxygen. All exposures were conducted at the onset of light. Results Mice in all three anesthetized groups exhibited a significant doubling of REM sleep during the first six-hours of the dark phase of the circadian schedule while only mice exposed to halothane displayed a significant increase in non-rapid eye movement sleep that peaked at 152% of baseline. Conclusion REM sleep rebound following exposure to volatile anesthetics suggests that these volatile anesthetics do not fully substitute for natural sleep. This result contrasts with the published actions of propofol for which no REM sleep rebound occurred. PMID:21934405

Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

PubMed

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.

Cell shape changes induced by cationic anesthetics

PubMed Central

1976-01-01

The effects of local anesthetics on cultivated macrophages were studied in living preparations and recorded in still pictures and time-lapse cine-micrographs. Exposure to 12mM lidocaine or 1.5 mM tetracaine resulted in rounding in 10-15 min. Rounding was characterized by cell contraction, marked increase in retraction fibrils, withdrawal of cell processes, and, in late stages, pulsation-like activity and zeiosis. Cells showed appreciable membrane activity as they rounded. Respreading was complete within 15 min of perfusion in drug-free medium and entailed a marked increase in surface motility over control periods. As many as eight successive cycles of rounding and spreading were obtained with lidocaine without evidence of cell damage. The effects of anesthetics were similar to those observed with EDTA, but ethylene- glycol-bis(beta-aminoethylether)-N, N'-tetraacetic acid-Mg was ineffective. Rounding was also induced by benzocaine, an anesthetic nearly uncharged at pH 7.0. Quaternary (nondischargeable) compounds were of low activity, presumably because they are slow permeants. Lidocaine induced rounding at 10 degrees C and above but was less effective at 5 degrees C and ineffective at 0 degrees C. Rounding by the anesthetic was also obtained in media depleted or Na or enriched with 10 mM Ca or Mg. The latter finding, together with the failure of tetrodotoxin to induce rounding, suggests that the anesthetic effect is unrelated to inhibition of sodium conductance. It is possible that the drugs influence divalent ion fluxes or some component of the contractile cells' machinery, but a metabolic target of action cannot yet be excluded. PMID:814194

Anesthetic level prediction using a QCM based E-nose.

PubMed

Saraoğlu, H M; Ozmen, A; Ebeoğlu, M A

2008-06-01

Anesthetic level measurement is a real time process. This paper presents a new method to measure anesthesia level in surgery rooms at hospitals using a QCM based E-Nose. The E-Nose system contains an array of eight different coated QCM sensors. In this work, the best linear reacting sensor is selected from the array and used in the experiments. Then, the sensor response time was observed about 15 min using classic method, which is impractical for on-line anesthetic level detection during a surgery. Later, the sensor transition data is analyzed to reach a decision earlier than the classical method. As a result, it is found out that the slope of transition data gives valuable information to predict the anesthetic level. With this new method, we achieved to find correct anesthetic levels within 100 s.

Prevalence of hazardous exposures in veterinary practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiggins, P.; Schenker, M.B.; Green, R.

1989-01-01

All female graduates of a major U.S. veterinary school were surveyed by mailed questionnaire to obtain details of work practice and hazard exposure during the most recent year worked and during all pregnancies. Exposure questions were based on previously implicated occupational hazards which included anesthetic gases, radiation, zoonoses, prostaglandins, vaccines, physical trauma, and pesticides. The response rate was 86% (462/537). We found that practice type and pregnancy status were major determinants of hazard exposure within the veterinary profession. Small-animal practitioners reported the highest rates of exposure to anesthetic gas (94%), X-ray (90%), and pesticides (57%). Large-animal practitioners reported greater ratesmore » of trauma (64%) and potential exposure to prostaglandins (92%), Brucella abortus vaccine (23%), and carbon monoxide (18%). Potentially hazardous workplace practices or equipment were common. Forty-one percent of respondents who reported taking X-rays did not wear film badges, and 76% reported physically restraining animals for X-ray procedures. Twenty-seven percent of the respondents exposed to anesthetic gases worked at facilities which did not have waste anesthetic gas scavenging systems. Women who worked as veterinarians during a pregnancy attempted to reduce exposures to X-rays, insecticides, and other potentially hazardous exposures. Some potentially hazardous workplace exposures are common in veterinary practice, and measures to educate workers and to reduce these exposures should not await demonstration of adverse health effects.« less

Anesthetic-Related Neurotoxicity and Neuroimaging in Children: A Call for Conversation.

PubMed

Bjur, Kara A; Payne, Eric T; Nemergut, Michael E; Hu, Danqing; Flick, Randall P

2017-05-01

Each year millions of young children undergo procedures requiring sedation or general anesthesia. An increasing proportion of the anesthetics used are provided to optimize diagnostic imaging studies such as magnetic resonance imaging. Concern regarding the neurotoxicity of sedatives and anesthetics has prompted the US Food and Drug Administration to change labeling of anesthetics and sedative agents warning against repeated or prolonged exposure in young children. This review aims to summarize the risk of anesthesia in children with an emphasis on anesthetic-related neurotoxicity, acknowledge the value of pediatric neuroimaging, and address this call for conversation.

Anesthetic management of Costello syndrome: a case report.

PubMed

Williams, Christol

2014-04-01

Costello syndrome is a rare genetic disorder with an estimated 300 medical cases worldwide. Typical features that characterize this syndrome include short stature, macrocephaly, developmental delay, loose skin folds, distinctive coarse facial features, and multiorgan system anomalies. The following case report discusses the anesthetic management for a 3-year-old boy undergoing general anesthesia for a scheduled dental restoration, hydrocelectomy, inguinal hernia repair, and bilateral myringotomy with placement of pressure equalization tubes. A scarcity of literature for the anesthetic management of Costello syndrome (also known as faciocutaneoskeletal syndrome) exists. Utilizing an overview of the pertinent literature, clinical practice recommendations are suggested for the anesthetic implications of managing a pediatric patient with this rare syndrome.

Topical Ocular Anesthetic Abuse Among Iranian Welders: Time for Action

PubMed Central

Sharifi, Ali; Sharifi, Hamid; Karamouzian, Mohammad; Mokhtari, Mahmoud; Esmaeili, Hamidreza Hosein; Nejad, Afshin Sarafi; Rahmatian, Mohammad

2013-01-01

Purpose: The purpose of this study is to estimate the prevalence of topical ocular anesthetic abuse among welders in Iran and suggest public health solutions for this issue. Methods: In this cross-sectional study, 390 welders were randomly recruited and queried on the use of anesthetic drops. A questionnaire was administered through structured one-on-one interviews conducted by the first author. Results: A total of 314 welders (80.5%) declared that they had used topical anesthetics at least once during their working lives. Almost 90% of them stated a preference for self-treatment over seeking help from a physician due to cultural and financial reasons. The most commonly used topical anesthetic was tetracaine. Most of the subjects (97.4%) had obtained the drugs from pharmacies without a prescription. Conclusions: The prevalence of topical ocular anesthetic abuse among welders in Iran is alarmingly high and may partially be due to cultural issues. Although most physicians are aware that topical anesthetics should only be used as a diagnostic tool, there is a crucial need to re-emphasize the ocular risks associated with chronic use of these medications. Educational programs for both physicians and the public are necessary to address the problem. PMID:24339685

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

PubMed

Vlassakov, Kamen V; Kissin, Igor

2014-01-01

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.

Anesthetic Binding in a Pentameric Ligand-Gated Ion Channel: GLIC

PubMed Central

Chen, Qiang; Cheng, Mary Hongying; Xu, Yan; Tang, Pei

2010-01-01

Cys-loop receptors are molecular targets of general anesthetics, but the knowledge of anesthetic binding to these proteins remains limited. Here we investigate anesthetic binding to the bacterial Gloeobacter violaceus pentameric ligand-gated ion channel (GLIC), a structural homolog of cys-loop receptors, using an experimental and computational hybrid approach. Tryptophan fluorescence quenching experiments showed halothane and thiopental binding at three tryptophan-associated sites in the extracellular (EC) domain, transmembrane (TM) domain, and EC-TM interface of GLIC. An additional binding site at the EC-TM interface was predicted by docking analysis and validated by quenching experiments on the N200W GLIC mutant. The binding affinities (KD) of 2.3 ± 0.1 mM and 0.10 ± 0.01 mM were derived from the fluorescence quenching data of halothane and thiopental, respectively. Docking these anesthetics to the original GLIC crystal structure and the structures relaxed by molecular dynamics simulations revealed intrasubunit sites for most halothane binding and intersubunit sites for thiopental binding. Tryptophans were within reach of both intra- and intersubunit binding sites. Multiple molecular dynamics simulations on GLIC in the presence of halothane at different sites suggested that anesthetic binding at the EC-TM interface disrupted the critical interactions for channel gating, altered motion of the TM23 linker, and destabilized the open-channel conformation that can lead to inhibition of GLIC channel current. The study has not only provided insights into anesthetic binding in GLIC, but also demonstrated a successful fusion of experiments and computations for understanding anesthetic actions in complex proteins. PMID:20858424

[Do anesthetic techniques influence postoperative outcomes? Part II].

PubMed

Esteve, N; Valdivia, J; Ferrer, A; Mora, C; Ribera, H; Garrido, P

2013-02-01

The knowledge of the influence of anesthetic techniques in postoperative outcomes has opened a large field of research in recent years. In this second part, we review some of the major controversies arising from the literature on the impact of anesthetic techniques on postoperative outcomes in 6 areas: postoperative cognitive dysfunction, chronic postoperative pain, cancer recurrence, postoperative nausea/vomiting, surgical outcomes, and resources utilization. The development of protective and preventive anesthetic strategies against short and long-term postoperative complications will probably occupy an important role in our daily anesthetic practice. Dynamic postoperative pain control has been confirmed as one of the basic requirements of accelerated postoperative recovery programs ("fast-track surgery"), and it is also a preventive factor for development of chronic postoperative pain. The weight of anesthetic technique on postoperative immunosuppression is to be defined. The potential influence of anesthesia on cancer recurrence, is a highly controversial area of research. The classic pattern of perioperative fluid therapy may increase postoperative complications. On the other hand, the maintenance of normoglycemia and normothermia was associated with a decreased postoperative morbidity. The high volume of surgical procedures means that the adequacy of human, organizational and technological resources have a major impact on overall costs. Copyright © 2011 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España, S.L. All rights reserved.

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

PubMed

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). Copyright © 2011 Wiley Periodicals, Inc.

Destructive treatment of waste gas by catalytic afterburning and adsorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eppel, S.A.; Kochetkova, R.P.; Kolisnyk, G.P.

1983-07-01

Because of the considerable energy costs involved in the use of catalytic afterburning to clean up waste gases, an alternative method is suggested: adsorption with the use of low-cost adsorbents that are regenerated by destruction of the substances that has been taken up. Activated semicoke (ASK) is proposed as an adsorbent and tested. On the basis of the results, ASK is recommended for the treatment of waste gases to remove oxygen-containing, sulfurcontaining, and tarry compounds.

Anesthetic induction with guaifenesin and propofol in adult horses.

PubMed

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.

General anesthetics and cytotoxicity: possible implications for brain health.

PubMed

Armstrong, Ryden; Xu, Fenglian; Arora, Anish; Rasic, Nivez; Syed, Naweed I

2017-04-01

The search for agents that bring about faster induction and quicker recovery in the operating room have yielded numerous anesthetics whose mechanisms of action and potential toxic side effects remain unknown, especially in the young and aging brain. Taking advantage of our clinical and basic science expertise, here we subject the reader to an interesting perspective vis-à-vis the current applications of general anesthetics, and present evidence for their neurotoxic effects on the developing and elderly brains. Recent studies have called into question the safety of general anesthetics, especially with regards to potentially significant detrimental impacts on the developing brains of young children, and cognitive decline in the elderly - often following multiple episodes of anesthesia. Despite accumulating evidence from animal studies demonstrating that general anesthesia leads to neurodegeneration and cognitive impairment, to date a clear consensus on the impact of anesthetics in humans remains elusive. Because a direct impact of anesthetics on human neuronal networks is often difficult to deduce experimentally, most laboratories have resorted to animal models - albeit with limited success in translating these findings back to the clinic. Moreover, the precise mechanisms that lead to potential cognitive, learning, and memory decline in young and elderly patients also remain to be fully defined. This review will focus primarily on the cytotoxic effects of anesthetics, and offer some practical resolutions that may attenuate their long-term harm. An urgent need for studies on animal models and an increased focus on highly controlled prospective epidemiological studies is also reinforced.

Comparison of use of an infrared anesthetic gas monitor and refractometry for measurement of anesthetic agent concentrations.

PubMed

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.

Radionuclide-anesthetic flow study: a new technique for the study of regional anesthesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauman, J.M.; Middaugh, R.E.; Cawthon, M.A.

1986-09-01

A new technique to study the dynamics of in vivo distribution of regional anesthetics is described. Five hundred microcuries of technetium-99m diethylenetriaminepentaacetic acid (DTPA) added to the anesthetic in a syringe prior to injection allows both dynamic and static imaging to assess the initial distribution of the injected anesthetic. Superimposed bone scans or transmission scans help delineate anatomy. The radionuclide-anesthetic flow study is a simple, safe technique to investigate both the spread of regional anesthetics and the factors that affect it.

75 FR 14604 - Guidance for Industry on Anesthetics for Companion Animals; Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

...] Guidance for Industry on Anesthetics for Companion Animals; Availability AGENCY: Food and Drug... availability of Guidance for Industry 192 entitled ``Anesthetics for Companion Animals.'' This guidance makes recommendations for the development of anesthetic new animal drug products for companion animals. The guidance...

Canonical partition functions: ideal quantum gases, interacting classical gases, and interacting quantum gases

NASA Astrophysics Data System (ADS)

Zhou, Chi-Chun; Dai, Wu-Sheng

2018-02-01

In statistical mechanics, for a system with a fixed number of particles, e.g. a finite-size system, strictly speaking, the thermodynamic quantity needs to be calculated in the canonical ensemble. Nevertheless, the calculation of the canonical partition function is difficult. In this paper, based on the mathematical theory of the symmetric function, we suggest a method for the calculation of the canonical partition function of ideal quantum gases, including ideal Bose, Fermi, and Gentile gases. Moreover, we express the canonical partition functions of interacting classical and quantum gases given by the classical and quantum cluster expansion methods in terms of the Bell polynomial in mathematics. The virial coefficients of ideal Bose, Fermi, and Gentile gases are calculated from the exact canonical partition function. The virial coefficients of interacting classical and quantum gases are calculated from the canonical partition function by using the expansion of the Bell polynomial, rather than calculated from the grand canonical potential.

The immune response to anesthesia: part 2 sedatives, opioids, and injectable anesthetic agents.

PubMed

Anderson, Stacy L; Duke-Novakovski, Tanya; Singh, Baljit

2014-11-01

To review the immune response to injectable anesthetics and sedatives and to compare the immunomodulatory properties between inhalation and injectable anesthetic protocols. Review. Multiple literature searches were performed using PubMed and Google Scholar from March 2012 through November 2013. Relevant anesthetic and immune terms were used to search databases without year published or species constraints. The online database for Veterinary Anaesthesia and Analgesia and the Journal of Veterinary Emergency and Critical Care were searched by issue starting in 2000 for relevant articles. Sedatives, injectable anesthetics, opioids, and local anesthetics have immunomodulatory effects that may have positive or negative consequences on disease processes such as endotoxemia, generalized sepsis, tumor growth and metastasis, and ischemia-reperfusion injury. Therefore, anesthetists should consider the immunomodulatory effects of anesthetic drugs when designing anesthetic protocols for their patients. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Cardiovascular effects of torcetrapib in conscious and pentobarbital-anesthetized dogs.

PubMed

Polakowski, James S; King, Andrew J; Campbell, Thomas J; Nelson, Richard A; Preusser, Lee C; Kempf-Grote, Anita J; Marsh, Kennan C; Gintant, Gary A; Cox, Bryan F; Mittelstadt, Scott W

2009-12-01

Torcetrapib is a cholesteryl ester transfer protein inhibitor with an undesired response of increasing arterial pressure in humans. Pressor responses to torcetrapib have been demonstrated in multiple preclinical species. However, these studies have not related plasma concentrations to observed effects. Our purpose was to 1) characterize the cardiovascular responses of torcetrapib in conscious and anesthetized dogs with measured plasma concentrations; and 2) characterize the hemodynamic effects contributing to hypertension using comprehensively instrumented anesthetized dogs. Torcetrapib was dosed orally (3, 30 mg/kg) and intravenously (0.01, 0.33, 0.1 mg/kg) in conscious and anesthetized dogs, respectively. Mean arterial pressure and heart rate were monitored in both models; additional parameters were measured in anesthetized dogs. Plasma drug concentrations were assessed in both models. In conscious and anesthetized dogs, torcetrapib increased mean arterial pressure 25 and 18 mm Hg and heart rate 35 and 21 beats/min, at 2.94 and 3.99 microg/mL, respectively. In anesthetized dogs, torcetrapib increased pulmonary arterial pressure, both systemic and pulmonary hypertension driven by increases in vascular resistance. The compound increased rate pressure product and myocardial contractility while decreasing time to systolic pressure recovery and ejection time. Thus, torcetrapib-induced pressor responses are mediated by systemic and pulmonary vasoconstriction and are associated with increased myocardial oxygen consumption and positive inotropy.

Differential General Anesthetic Effects on Microglial Cytokine Expression

PubMed Central

Ye, Xuefei; Lian, Qingquan; Eckenhoff, Maryellen F.; Eckenhoff, Roderic G.; Pan, Jonathan Z.

2013-01-01

Post-operative cognitive dysfunction has been widely observed, especially in older patients. An association of post-operative cognitive dysfunction with the neurodegenerative diseases, such as Alzheimer's disease, has been suggested. Neuroinflammation contributes to Alzheimer pathology, through elevated pro-inflammatory cytokines and microglial activation in the CNS leading to neuronal damage, synaptic disruption and ultimately cognitive dysfunction. We compare the effects of three different, clinically-used, anesthetics on microglial activation with, and without, the prototypical inflammatory trigger, lipopolysaccharide (LPS). Microglial BV-2 cell cultures were first exposed to isoflurane, sevoflurane (each at 2 concentrations) or propofol for 6 h, and cytokine levels measured in lysates and media. The same experiments were repeated after 1 h LPS pre-treatment. We found; 1) anesthetics alone have either no or only a small effect on cytokine expression; 2) LPS provoked a large increase in microglia cytokine expression; 3) the inhaled anesthetics either had no effect on LPS-evoked responses or enhanced it; 4) propofol nearly eliminated the LPS pro-inflammatory cytokine response and improved cell survival as reflected by lactate dehydrogenase release. These data suggest that propofol may be a preferred anesthetic when it is desirable to minimize neuroinflammation. PMID:23382826

Xenon and Other Volatile Anesthetics Change Domain Structure in Model Lipid Raft Membranes

PubMed Central

Weinrich, Michael; Worcester, David L.

2014-01-01

Inhalation anesthetics have been in clinical use for over 160 years, but the molecular mechanisms of action continue to be investigated. Direct interactions with ion channels received much attention after it was found that anesthetics do not change the structure of homogeneous model membranes. However, it was recently found that halothane, a prototypical anesthetic, changes domain structure of a binary lipid membrane. The noble gas xenon is an excellent anesthetic and provides a pivotal test of the generality of this finding, extended to ternary lipid raft mixtures. We report that xenon and conventional anesthetics change the domain equilibrium in two canonical ternary lipid raft mixtures. These findings demonstrate a membrane-mediated mechanism whereby inhalation anesthetics can affect the lipid environment of trans-membrane proteins. PMID:24299622

Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

NASA Astrophysics Data System (ADS)

Zhang, Lei; Wang, Shuxiao; Wu, Qingru; Wang, Fengyang; Lin, Che-Jen; Zhang, Leiming; Hui, Mulin; Yang, Mei; Su, Haitao; Hao, Jiming

2016-02-01

Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg0 to gaseous divalent mercury (Hg2+), with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp). Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g., TiO2, Fe2O3, etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34-85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD) captures 60-95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg0 fraction (66-82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29-90 %) from non-ferrous metal smelting, cement and

Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

NASA Astrophysics Data System (ADS)

Zhang, L.; Wang, S. X.; Wu, Q. R.; Wang, F. Y.; Lin, C.-J.; Zhang, L. M.; Hui, M. L.; Hao, J. M.

2015-11-01

Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, municipal solid waste incinerators, and biomass burning. Mercury in coal, ores and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of gaseous elemental mercury (Hg0) to gaseous divalent mercury (Hg2+), with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp). Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g.,TiO2, Fe2O3, etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34-85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD) captures 60-95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher fraction (66-82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29-90 %) from non

Disconnecting Consciousness: Is There a Common Anesthetic End Point?

PubMed

Hudetz, Anthony G; Mashour, George A

2016-11-01

A quest for a systems-level neuroscientific basis of anesthetic-induced loss and return of consciousness has been in the forefront of research for the past 2 decades. Recent advances toward the discovery of underlying mechanisms have been achieved using experimental electrophysiology, multichannel electroencephalography, magnetoencephalography, and functional magnetic resonance imaging. By the careful dosing of various volatile and IV anesthetic agents to the level of behavioral unresponsiveness, both specific and common changes in functional and effective connectivity across large-scale brain networks have been discovered and interpreted in the context of how the synthesis of neural information might be affected during anesthesia. The results of most investigations to date converge toward the conclusion that a common neural correlate of anesthetic-induced unresponsiveness is a consistent depression or functional disconnection of lateral frontoparietal networks, which are thought to be critical for consciousness of the environment. A reduction in the repertoire of brain states may contribute to the anesthetic disruption of large-scale information integration leading to unconsciousness. In future investigations, a systematic delineation of connectivity changes with multiple anesthetics using the same experimental design, and the same analytical method will be desirable. The critical neural events that account for the transition between responsive and unresponsive states should be assessed at similar anesthetic doses just below and above the loss or return of responsiveness. There will also be a need to identify a robust, sensitive, and reliable measure of information transfer. Ultimately, finding a behavior-independent measure of subjective experience that can track covert cognition in unresponsive subjects and a delineation of causal factors versus correlated events will be essential to understand the neuronal basis of human consciousness and unconsciousness.

Binding site and affinity prediction of general anesthetics to protein targets using docking.

PubMed

Liu, Renyu; Perez-Aguilar, Jose Manuel; Liang, David; Saven, Jeffery G

2012-05-01

The protein targets for general anesthetics remain unclear. A tool to predict anesthetic binding for potential binding targets is needed. In this study, we explored whether a computational method, AutoDock, could serve as such a tool. High-resolution crystal data of water-soluble proteins (cytochrome C, apoferritin, and human serum albumin), and a membrane protein (a pentameric ligand-gated ion channel from Gloeobacter violaceus [GLIC]) were used. Isothermal titration calorimetry (ITC) experiments were performed to determine anesthetic affinity in solution conditions for apoferritin. Docking calculations were performed using DockingServer with the Lamarckian genetic algorithm and the Solis and Wets local search method (http://www.dockingserver.com/web). Twenty general anesthetics were docked into apoferritin. The predicted binding constants were compared with those obtained from ITC experiments for potential correlations. In the case of apoferritin, details of the binding site and their interactions were compared with recent cocrystallization data. Docking calculations for 6 general anesthetics currently used in clinical settings (isoflurane, sevoflurane, desflurane, halothane, propofol, and etomidate) with known 50% effective concentration (EC(50)) values were also performed in all tested proteins. The binding constants derived from docking experiments were compared with known EC(50) values and octanol/water partition coefficients for the 6 general anesthetics. All 20 general anesthetics docked unambiguously into the anesthetic binding site identified in the crystal structure of apoferritin. The binding constants for 20 anesthetics obtained from the docking calculations correlate significantly with those obtained from ITC experiments (P = 0.04). In the case of GLIC, the identified anesthetic binding sites in the crystal structure are among the docking predicted binding sites, but not the top ranked site. Docking calculations suggest a most probable binding site

Mechanisms of Anesthetic Action and Neurotoxicity: Lessons from Molluscs

PubMed Central

Armstrong, Ryden; Riaz, Saba; Hasan, Sean; Iqbal, Fahad; Rice, Tiffany; Syed, Naweed

2018-01-01

Anesthesia is a prerequisite for most surgical procedures in both animals and humans. Significant strides have been made in search of effective and safer compounds that elicit rapid induction and recovery from anesthesia. However, recent studies have highlighted possible negative effects of several anesthetic agents on the developing brain. The precise nature of this cytotoxicity remains to be determined mainly due to the complexity and the intricacies of the mammalian brain. Various invertebrates have contributed significantly toward our understanding of how both local and general anesthetics affect intrinsic membrane and synaptic properties. Moreover, the ability to reconstruct in vitro synapses between individually identifiable pre- and postsynaptic neurons is a unique characteristic of molluscan neurons allowing us to ask fundamental questions vis-à-vis the long-term effects of anesthetics on neuronal viability and synaptic connectivity. Here, we highlight some of the salient aspects of various molluscan organisms and their contributions toward our understanding of the fundamental mechanisms underlying the actions of anesthetic agents as well as their potential detrimental effects on neuronal growth and synaptic connectivity. We also present some novel preliminary data regarding a newer anesthetic agent, dexmedetomidine, and its effects on synaptic transmission between Lymnaea neurons. The findings presented here underscore the importance of invertebrates for research in the field of anesthesiology while highlighting their relevance to both vertebrates and humans. PMID:29410627

Pediatric heart transplantation: demographics, outcomes, and anesthetic implications.

PubMed

Schure, Annette Y; Kussman, Barry D

2011-05-01

The evolving demographics, outcomes, and anesthetic management of pediatric heart transplant recipients are reviewed. As survival continues to improve, an increasing number of these patients will present to our operating rooms and sedation suites. It is therefore important that all anesthesiologists, not only those specialized in cardiac anesthesia, have a basic understanding of the physiologic changes in the transplanted heart and the anesthetic implications thereof. © 2010 Blackwell Publishing Ltd.

Using Waste Heat for External Processes (English/Chinese) (Fact Sheet) (in Chin3se; English)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Chinese translation of the Using Waste Heat for External Processes fact sheet. Provides suggestions on how to use waste heat in industrial applications. The temperature of exhaust gases from fuel-fired industrial processes depends mainly on the process temperature and the waste heat recovery method. Figure 1 shows the heat lost in exhaust gases at various exhaust gas temperatures and percentages of excess air. Energy from gases exhausted from higher temperature processes (primary processes) can be recovered and used for lower temperature processes (secondary processes). One example is to generate steam using waste heat boilers for the fluid heaters used inmore » petroleum crude processing. In addition, many companies install heat exchangers on the exhaust stacks of furnaces and ovens to produce hot water or to generate hot air for space heating.« less

Evaluating anesthetic protocols for functional blood flow imaging in the rat eye

NASA Astrophysics Data System (ADS)

Moult, Eric M.; Choi, WooJhon; Boas, David A.; Baumann, Bernhard; Clermont, Allen C.; Feener, Edward P.; Fujimoto, James G.

2017-01-01

The purpose of this study is to evaluate the suitability of five different anesthetic protocols (isoflurane, isoflurane-xylazine, pentobarbital, ketamine-xylazine, and ketamine-xylazine-vecuronium) for functional blood flow imaging in the rat eye. Total retinal blood flow was measured at a series of time points using an ultrahigh-speed Doppler OCT system. Additionally, each anesthetic protocol was qualitatively evaluated according to the following criteria: (1) time-stability of blood flow, (2) overall rate of blood flow, (3) ocular immobilization, and (4) simplicity. We observed that different anesthetic protocols produced markedly different blood flows. Different anesthetic protocols also varied with respect to the four evaluated criteria. These findings suggest that the choice of anesthetic protocol should be carefully considered when designing and interpreting functional blood flow studies in the rat eye.

Anesthetic Challenges in Robotic-assisted Urologic Surgery

PubMed Central

Hsu, Richard L; Kaye, Alan D; Urman, Richard D

2013-01-01

Robotic-assisted surgery has evolved over the past two decades with constantly improving technology, assisting surgeons in multiple subspecialty disciplines. The surgical requirements of lithotomy and steep Trendelenburg positions, along with the creation of a pneumoperitoneum and limited access to the patient, all present anesthetic management challenges in urologic surgery. Patient positioning requirements can cause significant physiologic effects and may result in many complications. Good communication among team members and knowledge of the nuances of robotic surgery have the potential to improve patient outcomes, increase efficiency, and reduce surgical and anesthetic complications. PMID:24659914

Disconnecting Consciousness: Is There a Common Anesthetic End-Point?

PubMed Central

Hudetz, Anthony G.; Mashour, George A.

2016-01-01

A quest for a systems-level neuroscientific basis of anesthetic-induced loss and return of consciousness has been in the forefront of research of the last two decades. Recent advances toward the discovery of underlying mechanisms have been achieved using experimental electrophysiology, multichannel electroencephalography, magnetoencephalography, and functional magnetic resonance imaging. By the careful dosing of various volatile and IV anesthetic agents to the level of behavioral unresponsiveness, both specific and common changes in functional and effective connectivity across large-scale brain networks have been discovered and interpreted in the context of how the synthesis of neural information might be affected during anesthesia. The results of most investigations to date converge toward the conclusion that a common neural correlate of anesthetic-induced unresponsiveness is a consistent depression or functional disconnection of lateral frontoparietal networks, which are thought to be critical for consciousness of the environment. A reduction in the repertoire of brain states may contribute to the anesthetic disruption of large-scale information integration leading to unconsciousness. In future investigations, a systematic delineation of connectivity changes with multiple anesthetics using the same experimental design and the same analytical method will be desirable. The critical neural events that account for the transition between responsive and unresponsive states should be assessed at similar anesthetic doses just below and above the loss or return of responsiveness. There will also be a need to identify a robust, sensitive, and reliable measure of information transfer. Ultimately, finding a behavior-independent measure of subjective experience that can track covert cognition in unresponsive subjects and a delineation of causal factors vs. correlated events will be essential to understand the neuronal basis of human consciousness and unconsciousness. PMID

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

PubMed Central

Vlassakov, Kamen V; Kissin, Igor

2014-01-01

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. PMID:25525336

Electrochemical incineration of wastes

NASA Technical Reports Server (NTRS)

Bockris, J. O. M.; Bhardwaj, R. C.; Tennakoon, C. L. K.

1993-01-01

There is an increasing concern regarding the disposal of human wastes in space vehicles. It is of utmost importance to convert such wastes into harmless products which can be recycled into an Environmental Life Support System (CELSS), which incorporates the growth of plants (e.g. wheat) and algae to supplement the diet of the astronauts. Chemical treatments have proven relatively unsatisfactory and tend to be increasingly so with increase of the mission duration. Similarly, the use of heat to destroy wastes and convert them to CO2 by the use of air or oxygen has the disadvantage and difficulty of dissipating heat in a space environment and to the inevitable presence of oxides of nitrogen and carbon monoxide in the effluent gases. In particular, electrochemical techniques offer several advantages including low temperatures which may be used and the absence of any NO and CO in the evolved gases. Successful research has been carried out in the electrochemical oxidation of wastes over the last several years. The major task for 1992 was to conduct parametric studies in preparation for the building of a breadboard system, i.e., an actual practical device to consume the daily waste output of one astronaut in 24 hours, electrochemical incineration of human wastes in space vehicles. One of the main objectives was to decide on the type of three dimensional or other electrode system that would suit this purpose. The various types of electrode systems which were considered for this purpose included: rotating disc electrode, micro-electrode (an array), vibrating electrode, jet electrode, and packed bed electrode.

Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke.

PubMed

Wang, Hailian; Li, Peiying; Xu, Na; Zhu, Ling; Cai, Mengfei; Yu, Weifeng; Gao, Yanqin

2016-01-01

Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke

PubMed Central

Wang, Hailian; Li, Peiying; Xu, Na; Zhu, Ling; Cai, Mengfei; Yu, Weifeng; Gao, Yanqin

2016-01-01

Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms. PMID:28217291

Comparison of Two Anesthetic Methods for Intravitreal Ozurdex Injection

PubMed Central

Karabaş, V. Levent; Özkan, Berna; Koçer, Çiğdem Akdağ; Altıntaş, Özgül; Pirhan, Dilara; Yüksel, Nurşen

2015-01-01

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. PMID:25949822

Comparison of two anesthetic methods for intravitreal ozurdex injection.

PubMed

Karabaş, V Levent; Özkan, Berna; Koçer, Çiğdem Akdağ; Altıntaş, Özgül; Pirhan, Dilara; Yüksel, Nurşen

2015-01-01

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.

Binding Site and Affinity Prediction of General Anesthetics to Protein Targets Using Docking

PubMed Central

Liu, Renyu; Perez-Aguilar, Jose Manuel; Liang, David; Saven, Jeffery G.

2012-01-01

Background The protein targets for general anesthetics remain unclear. A tool to predict anesthetic binding for potential binding targets is needed. In this study, we explore whether a computational method, AutoDock, could serve as such a tool. Methods High-resolution crystal data of water soluble proteins (cytochrome C, apoferritin and human serum albumin), and a membrane protein (a pentameric ligand-gated ion channel from Gloeobacter violaceus, GLIC) were used. Isothermal titration calorimetry (ITC) experiments were performed to determine anesthetic affinity in solution conditions for apoferritin. Docking calculations were performed using DockingServer with the Lamarckian genetic algorithm and the Solis and Wets local search method (https://www.dockingserver.com/web). Twenty general anesthetics were docked into apoferritin. The predicted binding constants are compared with those obtained from ITC experiments for potential correlations. In the case of apoferritin, details of the binding site and their interactions were compared with recent co-crystallization data. Docking calculations for six general anesthetics currently used in clinical settings (isoflurane, sevoflurane, desflurane, halothane, propofol, and etomidate) with known EC50 were also performed in all tested proteins. The binding constants derived from docking experiments were compared with known EC50s and octanol/water partition coefficients for the six general anesthetics. Results All 20 general anesthetics docked unambiguously into the anesthetic binding site identified in the crystal structure of apoferritin. The binding constants for 20 anesthetics obtained from the docking calculations correlate significantly with those obtained from ITC experiments (p=0.04). In the case of GLIC, the identified anesthetic binding sites in the crystal structure are among the docking predicted binding sites, but not the top ranked site. Docking calculations suggest a most probable binding site located in the

Performance characteristics of a diesel engine using low- and medium-energy gases as a fuel supplement (fumigation)

NASA Technical Reports Server (NTRS)

Monford, L. G.

1976-01-01

The use of low- and medium-energy gases derived from solid waste is investigated. Gases that simulate those gases that could be derived from refuse were injected into the air inlet of a 298-kilowatt (400 horsepower) diesel engine as a fuel supplement. This process is called fumigation. Three different gases with thermal-energy contents of 6.11 MJ/cu m (164 Btu/cu ft), 18.1 MJ/cu m (485 Btu/cu ft), and 18.8 MJ/cu m (505 Btu/cu ft, respectively, were used at rates ranging as high as 20 percent of the normal fuel oil energy at four different engine load points. The test results indicated approximately 100 percent gas energy utilization with no observable deleterious effect on the engine.

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

NASA Technical Reports Server (NTRS)

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.

Influence of Ventilation Strategies and Anesthetic Techniques on Regional Cerebral Oximetry in the Beach Chair Position: A Prospective Interventional Study with a Randomized Comparison of Two Anesthetics.

PubMed

Picton, Paul; Dering, Andrew; Alexander, Amir; Neff, Mary; Miller, Bruce S; Shanks, Amy; Housey, Michelle; Mashour, George A

2015-10-01

Beach chair positioning during general anesthesia is associated with cerebral oxygen desaturation. Changes in cerebral oxygenation resulting from the interaction of inspired oxygen fraction (FIO2), end-tidal carbon dioxide (PETCO2), and anesthetic choice have not been fully evaluated in anesthetized patients in the beach chair position. This is a prospective interventional within-group study of patients undergoing shoulder surgery in the beach chair position that incorporated a randomized comparison between two anesthetics. Fifty-six patients were randomized to receive desflurane or total intravenous anesthesia with propofol. Following induction of anesthesia and positioning, FIO2 and minute ventilation were sequentially adjusted for all patients. Regional cerebral oxygenation (rSO2) was the primary outcome and was recorded at each of five set points. While maintaining FIO2 at 0.3 and PETCO2 at 30 mmHg, there was a decrease in rSO2 from 68% (SD, 12) to 61% (SD, 12) (P < 0.001) following beach chair positioning. The combined interventions of increasing FIO2 to 1.0 and increasing PETCO2 to 45 mmHg resulted in a 14% point improvement in rSO2 to 75% (SD, 12) (P <0.001) for patients anesthetized in the beach chair position. There was no significant interaction effect of the anesthetic at the study intervention points. Increasing FIO2 and PETCO2 resulted in a significant increase in rSO2 that overcomes desaturation in patients anesthetized in the beach chair position and that appears independent of anesthetic choice.

Anesthetic Agents and Neuronal Autophagy. What We Know and What We Don't.

PubMed

Xu, Lili; Shen, Jianjun; McQuillan, Patrick M; Hu, Zhiyong

2018-01-01

Ethanol is known to have both γ-Aminobutyric acid agonist and Nmethyl- D-aspartate antagonist characteristics similar to commonly used volatile anesthetic agents. Recent evidence demonstrates that autophagy can reduce the development of ethanol induced neurotoxicity. Recent studies have found that general anesthesia can cause longterm impairment of both mitochondrial morphogenesis and synaptic transmission in the developing rat brain, both of which are accompanied by enhanced autophagy activity. Autophagy may play an important role in general anesthetic mediated neurotoxicity. This review outlines the role of autophagy in the development of anesthetic related neurotoxicity and includes an explanation of the role of autophagy in neuronal cell survival and death, the relationship between anesthetic agents and neuronal autophagy, possible molecular and cellular mechanisms underlying general anesthetic agent induced activation of neuronal autophagy in the developing brain, and potential therapeutic approaches aimed at modulating autophagic pathways. In a time- and concentration-dependent pattern, general anesthetic agents can disrupt intracellular calcium homeostasis which enhances both autophagy and apoptosis activation. The degree of neural cell injury may be ultimately determined by the interplay between autophagy and apoptosis. It appears likely that the increase in calcium flux associated with some anesthetic agents disrupts lysosomal function. This results in an over-activation of endosomal- lysosomal trafficking causing mitochondrial damage, reactive oxygen species upregulation, and lipid peroxidation. Autophagy may play a role in the development of anesthetic related neurotoxicity. Understanding this may lead to strategies or therapies aimed at preventing or ameliorating general anesthetic agent mediated neurotoxicity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Occurrence of paresthesia after dental local anesthetic administration in the United States.

PubMed

Garisto, Gabriella A; Gaffen, Andrew S; Lawrence, Herenia P; Tenenbaum, Howard C; Haas, Daniel A

2010-07-01

Several studies have suggested that the likelihood of paresthesia may depend on the local anesthetic used. The purpose of this study was to determine if the type of local anesthetic administered had any effect on reports of paresthesia in dentistry in the United States. The authors obtained reports of paresthesia involving dental local anesthetics during the period from November 1997 through August 2008 from the U.S. Food and Drug Administration Adverse Event Reporting System. They used chi(2) analysis to compare expected frequencies, on the basis of U.S. local anesthetic sales data, with observed reports of oral paresthesia. During the study period, 248 cases of paresthesia occurring after dental procedures were reported. Most cases (94.5 percent) involved mandibular nerve block. The lingual nerve was affected in 89.0 percent of cases. Reports involving 4 percent prilocaine and 4 percent articaine were 7.3 and 3.6 times, respectively, greater than expected (chi(2), P < .0001) on the basis of local anesthetic use by U.S. dentists. These data suggest that paresthesia occurs more commonly after use of 4 percent local anesthetic formulations. These findings are consistent with those reported in a number of studies from other countries. Until further research indicates otherwise, dentists should consider these results when assessing the risks and benefits of using 4 percent local anesthetics for mandibular block anesthesia.

Install Waste Heat Recovery Systems for Fuel-Fired Furnaces (English/Chinese) (Fact Sheet) (in Chinese; English)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Chinese translation of ITP fact sheet about installing Waste Heat Recovery Systems for Fuel-Fired Furnaces. For most fuel-fired heating equipment, a large amount of the heat supplied is wasted as exhaust or flue gases. In furnaces, air and fuel are mixed and burned to generate heat, some of which is transferred to the heating device and its load. When the heat transfer reaches its practical limit, the spent combustion gases are removed from the furnace via a flue or stack. At this point, these gases still hold considerable thermal energy. In many systems, this is the greatest single heat loss.more » The energy efficiency can often be increased by using waste heat gas recovery systems to capture and use some of the energy in the flue gas. For natural gas-based systems, the amount of heat contained in the flue gases as a percentage of the heat input in a heating system can be estimated by using Figure 1. Exhaust gas loss or waste heat depends on flue gas temperature and its mass flow, or in practical terms, excess air resulting from combustion air supply and air leakage into the furnace. The excess air can be estimated by measuring oxygen percentage in the flue gases.« less

Effects of Different Anesthetics on Oscillations in the Rat Olfactory Bulb

PubMed Central

Li, Anan; Zhang, Lei; Liu, Min; Gong, Ling; Liu, Qing; Xu, Fuqiang

2012-01-01

Different types of oscillations in the olfactory bulb (OB), including θ (1 to 4 and 5 to 12 Hz), β (13 to 30 Hz), and γ oscillations (31 to 64 and 65 to 90 Hz), are important in olfactory information processing and olfactory-related functions and have been investigated extensively in recent decades. The awake and anesthetized states, 2 different brain conditions, are used widely in electrophysiologic studies of OB. Chloral hydrate, pentobarbital, and urethane are commonly used anesthetics in these studies. However, the influence of these anesthetics on the oscillations has not been reported. In the present study, we recorded the local field potential (LFP) in the OB of rats that were freely moving or anesthetized with these agents. Chloral hydrate and pentobarbital had similar effects: they slightly affected the power of θ oscillations; significantly increased the power of β oscillations; significantly decreased the power of γ oscillations, and showed similar recovery of γ oscillations. Urethane had very different effects: it significantly increased oscillations at 1 to 4 Hz but decreased those at 5 to 12 Hz, decreased β and γ oscillations, and showed no overt recovery in γ oscillations. These results provide experimental evidence of different effects of various anesthetics on OB oscillations and suggest that the choice of anesthetic should consider the experimental application. PMID:23043811

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.

1986-08-19

The separation of polar gases from nonpolar gases may be effected by passing a mixture of nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

Efficacy and Safety of 5 Anesthetics in Adult Zebrafish (Danio rerio)

PubMed Central

Collymore, Chereen; Tolwani, Angela; Lieggi, Christine; Rasmussen, Skye

2014-01-01

Although the safety and efficacy of tricaine methanesulfonate (MS222) for anesthesia of fish are well established, other anesthetics used less commonly in fish have been less extensively evaluated. Therefore, we compared gradual cooling, lidocaine hydrochloride (300, 325, and 350 mg/L), metomidate hydrochloride (2, 4, 6, 8, and 10 mg/L), and isoflurane (0.5 mL/L) with MS222 (150 mg/L) for anesthesia of adult zebrafish. The efficacy and safety of each agent was evaluated by observing loss of equilibrium, slowing of opercular movement, response to tail-fin pinch, recovery time, and anesthesia-associated mortality rates. At 15 min after anesthetic recovery, we used a novel-tank test to evaluate whether anesthetic exposure influenced short-term anxiety-like behavior. Behavioral parameters measured included latency to enter and number of transitions to the upper half of the tank, number of erratic movements, and number of freezing bouts. Behavior after anesthesia was unaltered regardless of the anesthetic used. Efficacy and safety differed among the anesthetics evaluated. Gradual cooling was useful for short procedures requiring immobilization only, but all instrumentation and surfaces that come in contact with fish must be maintained at approximately 10 °C. MS222 and lidocaine hydrochloride at 325 mg/L were effective as anesthetic agents for surgical procedures in adult zebrafish, but isoflurane and high-dose lidocaine hydrochloride were unsuitable as sole anesthetic agents due to high (30%) mortality rates. Although MS222 remains the best choice for generating a surgical plane of anesthesia, metomidate hydrochloride and gradual cooling were useful for sedation and immobilization for nonpainful procedures. PMID:24602548

Identification of a putative binding site critical for general anesthetic activation of TRPA1.

PubMed

Ton, Hoai T; Phan, Thieu X; Abramyan, Ara M; Shi, Lei; Ahern, Gerard P

2017-04-04

General anesthetics suppress CNS activity by modulating the function of membrane ion channels, in particular, by enhancing activity of GABA A receptors. In contrast, several volatile (isoflurane, desflurane) and i.v. (propofol) general anesthetics excite peripheral sensory nerves to cause pain and irritation upon administration. These noxious anesthetics activate transient receptor potential ankyrin repeat 1 (TRPA1), a major nociceptive ion channel, but the underlying mechanisms and site of action are unknown. Here we exploit the observation that pungent anesthetics activate mammalian but not Drosophila TRPA1. Analysis of chimeric Drosophila and mouse TRPA1 channels reveal a critical role for the fifth transmembrane domain (S5) in sensing anesthetics. Interestingly, we show that anesthetics share with the antagonist A-967079 a potential binding pocket lined by residues in the S5, S6, and the first pore helix; isoflurane competitively disrupts A-967079 antagonism, and introducing these mammalian TRPA1 residues into dTRPA1 recapitulates anesthetic agonism. Furthermore, molecular modeling predicts that isoflurane and propofol bind to this pocket by forming H-bond and halogen-bond interactions with Ser-876, Met-915, and Met-956. Mutagenizing Met-915 or Met-956 selectively abolishes activation by isoflurane and propofol without affecting actions of A-967079 or the agonist, menthol. Thus, our combined experimental and computational results reveal the potential binding mode of noxious general anesthetics at TRPA1. These data may provide a structural basis for designing drugs to counter the noxious and vasorelaxant properties of general anesthetics and may prove useful in understanding effects of anesthetics on related ion channels.

Anesthetic Considerations for Transcatheter Pulmonary Valve Replacement.

PubMed

Gregory, Stephen H; Zoller, Jonathan K; Shahanavaz, Shabana; Chilson, Kelly L; Ridley, Clare H

2018-02-01

The introduction of transcatheter therapy for valvular heart disease has revolutionized the care of patients with valvular disorders. Pathologic regurgitation or stenosis of the pulmonary valve, right ventricular outflow tract, or a right ventricle-to-pulmonary artery conduit represent emerging indications for transcatheter therapy. To date, minimal literature exists detailing the anesthetic management of patients undergoing transcatheter pulmonary valve replacement. In this review, the pathophysiology and indications for transcatheter pulmonary valve replacement and possible complications unique to this procedure are reviewed. Anesthetic management, including preoperative assessment, intraoperative considerations, and early postoperative monitoring, are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

The Neurotoxicity of General Anesthetic Drugs: Emphasis on the Extremes of Age.

PubMed

Biddle, Chuck; Ford, Vincent

2017-01-01

A substantial body of research suggests that anesthetic exposure to patients who are very young or very old may impair cognitive, behavioral, and emotional development or recovery. In lower animal models of pre- and postnatal age, anesthetic exposure may impact inflammation, synaptogenesis, neuronal apoptosis, and glial cell development. To date, research in humans is inconclusive regarding the long-term cognitive and behavioral sequelae of general anesthesia in the young child. In older adults, postoperative cognitive dysfunction and cognitive delirium are identified as markers of anesthetic neurotoxicity. Existing neurological degenerative processes and other comorbidities in combination with the stress of surgery make evaluating the independent impact of anesthetic exposure difficult. Advances in research, imaging, and partnerships have enhanced the potential for understanding the impact of anesthetic exposure. In both populations, the resulting data and limitations faced in initial research efforts are catalysts for current prospective studies.

An Uncommon Complication With Use of Topical Local Anesthetic Agents: Methemoglobinemia.

PubMed

Panikkath, Ragesh; Panikkath, Deepa; Wischmeyer, Jason

Although the use of topical local anesthetics is generally safe, several potentially fatal complications have been reported. Methemoglobinemia is a rare but potentially fatal complication. Methemoglobin is a naturally occurring oxidized metabolite of hemoglobin, and physiologic levels (<1%) are normal. Methemoglobinemia can be congenital or acquired. Several drugs including topical anesthetic agents like benzocaine can induce this condition. Sudden appearance of cyanosis, with a disproportionately better oxygen saturation of 85% after use of local anesthetics can be a helpful for diagnosis.

Certain Hospital Waste Management Practices in Isfahan, Iran

PubMed Central

Ferdowsi, Ali; Ferdosi, Masoud; Mehrani, Zeinab; Narenjkar, Parisa

2012-01-01

Objectives: Infected hospital wastes are among hazardous wastes, and special treatment methods are needed for their disposal. Having information about present status of medical waste management systems is of great importance in finding weak, and for future planning. Such studies have not been done for most of the hospitals in Iran. Methods: This paper reports the results of a study on the present status of medical waste management in Isfahan hospitals. A ten page researcher made questionnaire was used to collect data in terms of collection, transportation, segregation, treatment and disposal. For assessment of autoclaves, standard tests including TST (Time, Steam, and Temperature) strip test and spore tests were used. Samples were made of stack gases of incinerators. Quantity and composition of hospital wastes in Isfahan were also measured manually. Results: Of all wastes in selected hospitals, 40% were infected wastes (1.59 kg/day/bed), which is 15 to 20% higher than World Health Organization (WHO) standards. TST and Spore test results were negative in all samples. Stack gases analysis showed high concentration of CO in some samples. Besides, the combustion efficiency in some samples is less than 99.5%, which is the standard criterion in Iran. Conclusions: This study may create awareness regarding the magnitude of the problem of waste management in hospitals of Isfahan and may stimulate interests for systematic control efforts for hospital waste disposal. Hospital waste management cannot succeed without documented plans, certain equipment, defined staff trainings, and periodic evaluations. PMID:22826762

Application of advanced preclinical models and methods in anesthetic neurotoxicity research.

PubMed

Wang, Cheng; Zhang, Xuan; Liu, Fang

2017-05-01

Recently, there has been increasing concern regarding the potential of anesthetics to disturb the long-term function of the central nervous system (CNS). The field of anesthesia-related toxicology, therefore, has engaged multiple scientific disciplines and utilized a variety of pre-clinical research models in an attempt to identify the basic characteristics of the anesthetic agents that may produce acute and/or chronic adverse effects on the CNS. This review discusses how the application of advanced research approaches and models, such as the nonhuman primate, neural stem cell-derived organotypic slice cultures and/or organs-on-chips systems, can serve as translational models of infantile anesthetic exposure. Utilization of these models may expeditiously decrease the uncertainty in the risk posed to children by postnatal anesthetic exposure. Copyright © 2017. Published by Elsevier Inc.

Volatile Anesthetics Improve Survival after Cecal Ligation and Puncture

PubMed Central

Herrmann, Inge K.; Castellon, Maricela; Schwartz, David E.; Hasler, Melanie; Urner, Martin; Hu, Guochang; Minshall, Richard D.; Beck-Schimmer, Beatrice

2016-01-01

Background Sepsis remains a leading cause of death in intensive care units. There is growing evidence that volatile anesthetics have beneficial immunomodulatory effects on complex inflammation-mediated conditions. The authors investigated the effect of volatile anesthetics on the overall survival of mice in a sepsis model of cecal ligation and puncture (CLP). Methods Mice (N = 12 per treatment group) were exposed to anesthetic concentrations of desflurane, isoflurane, and sevoflurane either during induction of sepsis or when the mice showed pronounced symptoms of inflammation. Overall survival, as well as organ function and inflammation was compared with the CLP group without intervention. Results With desflurane and sevoflurane conditioning (1.2 minimal alveolar concentration for 2 h immediately after induction of CLP) overall survival was improved to 58% and 83%, respectively, compared with 17% in the untreated CLP group. Isoflurane did not significantly affect outcome. Application of sevoflurane 24 h after sepsis induction significantly improved overall survival to 66%. Conclusions Administration of the volatile anesthetics desflurane and sevoflurane reduced CLP-induced mortality. Anesthesia may be a critical confounder when comparing study data where different anesthesia protocols were used. PMID:23867232

21 CFR 348.10 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 348.10 Section 348.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Active Ingredients § 348.10 Analgesic, anesthetic, and antipruritic active ingredients. The active...

21 CFR 346.16 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Analgesic, anesthetic, and antipruritic active... SERVICES (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.16 Analgesic, anesthetic, and antipruritic active ingredients. The active ingredient of the...

21 CFR 348.10 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 348.10 Section 348.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Active Ingredients § 348.10 Analgesic, anesthetic, and antipruritic active ingredients. The active...

21 CFR 346.16 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Analgesic, anesthetic, and antipruritic active... SERVICES (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.16 Analgesic, anesthetic, and antipruritic active ingredients. The active ingredient of the...

21 CFR 348.10 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 348.10 Section 348.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Active Ingredients § 348.10 Analgesic, anesthetic, and antipruritic active ingredients. The active...

21 CFR 346.16 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Analgesic, anesthetic, and antipruritic active... SERVICES (CONTINUED) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.16 Analgesic, anesthetic, and antipruritic active ingredients. The active ingredient of the...

21 CFR 348.10 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 348.10 Section 348.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Active Ingredients § 348.10 Analgesic, anesthetic, and antipruritic active ingredients. The active...

21 CFR 348.10 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 348.10 Section 348.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Active Ingredients § 348.10 Analgesic, anesthetic, and antipruritic active ingredients. The active...

Molecular interactions between general anesthetics and the 5HT2B receptor.

PubMed

Matsunaga, Felipe; Gao, Lu; Huang, Xi-Ping; Saven, Jeffery G; Roth, Bryan L; Liu, Renyu

2015-01-01

Serotonin modulates many processes through a family of seven serotonin receptors. However, no studies have screened for interactions between general anesthetics currently in clinical use and serotonergic G-protein-coupled receptors (GPCRs). Given that both intravenous and inhalational anesthetics have been shown to target other classes of GPCRs, we hypothesized that general anesthetics might interact directly with some serotonin receptors and thus modify their function. Radioligand binding assays were performed to screen serotonin receptors for interactions with propofol and isoflurane as well as for affinity determinations. Docking calculations using the crystal structure of 5-HT2B were performed to computationally confirm the binding assay results and locate anesthetic binding sites. The 5-HT2B class of receptors interacted significantly with both propofol and isoflurane in the primary screen. The affinities for isoflurane and propofol were determined to be 7.78 and .95 μM, respectively, which were at or below the clinical concentrations for both anesthetics. The estimated free energy derived from docking calculations for propofol (-6.70 kcal/mol) and isoflurane (-5.10 kcal/mol) correlated with affinities from the binding assay. The anesthetics were predicted to dock at a pharmacologically relevant binding site of 5HT2B. The molecular interactions between propofol and isoflurane with the 5-HT2B class of receptors were discovered and characterized. This finding implicates the serotonergic GPCRs as potential anesthetic targets.

Anesthetic exposure in the treatment of symptomatic urinary calculi in pregnant women.

PubMed

Rivera, Marcelino E; McAlvany, Kelly L; Brinton, Thomas S; Gettman, Matthew T; Krambeck, Amy E

2014-12-01

To assess the duration and total number of anesthetic exposures required for the treatment of urolithiasis during pregnancy, specifically comparing temporizing measures with active treatment because urolithiasis and its management may pose potential theoretical risks for the mother and fetus. We retrospectively reviewed patients with a confirmed diagnosis of urolithiasis during pregnancy who underwent surgical intervention from 1997 to 2012 at our institution. The number and duration of anesthetic exposures were assessed. We identified 26 women with urolithiasis during pregnancy, of which 15 (58%) were treated with temporizing stents and 11 (42%) with ureteroscopic stone extraction. In the ureteroscopy group, the median number of anesthetic exposures was 1.18 (interquartile range [IQR], 1-2), and the median total anesthetic time was 80 minutes (IQR, 37-126 minutes). In the stent group, 6 (40%) required multiple stent exchanges for a median of 1.47 (IQR, 1-3) anesthetic events and a median total anesthetic time of 70 minutes (IQR, 29-208 minutes). In the ureteral stent group, 7 women (47%) were induced before spontaneous labor due to inability to tolerate the stent. There was no difference in the number of anesthetic events (P = .208) or anesthesia time (P = .503) between stenting and ureteroscopy. Women undergoing ureteroscopic surgical intervention during pregnancy were at no greater risk in the number or cumulative duration of anesthesia exposure than women managed with temporizing ureteral stent placement and subsequent exchanges. Copyright © 2014 Elsevier Inc. All rights reserved.

Neuroprotective Effects of Intravenous Anesthetics: A New Critical Perspective

PubMed Central

Bilotta, Federico; Stazi, Elisabetta; Zlotnik, Alexander; Gruenbaum, Shaun E.; Rosa, Giovanni

2015-01-01

Perioperative cerebral damage can result in various clinical sequela ranging from minor neurocognitive deficits to catastrophic neurological morbidity with permanent impairment and death. The goal of neuroprotective treatments is to reduce the clinical effects of cerebral damage through two major mechanisms: increased tolerance of neurological tissue to ischemia and changes in intra-cellular responses to energy supply deprivation. In this review, we present the clinical evidence of intravenous anesthetics on perioperative neuroprotection, and we also provide a critical perspective for future studies. The neuroprotective efficacy of the intravenous anesthetics thiopental, propofol and etomidate is unproven. Lidocaine may be neuroprotective in non-diabetic patients who have undergoing cardiac surgery with cardiopulmonary bypass (CBP) or with a 48-hour infusion, but conclusive data are lacking. There are several limitations of clinical studies that evaluate postoperative cognitive dysfunction (POCD), including difficulties in identifying patients at high-risk and a lack of consensus for defining the “gold-standard” neuropsychological testing. Although a battery of neurocognitive tests remains the primary method for diagnosing POCD, recent evidence suggests a role for novel biomarkers and neuroimaging to preemptively identify patients more susceptible to cognitive decline in the perioperative period. Current evidence, while inconclusive, suggest that intravenous anesthetics may be both neuroprotective and neurotoxic in the perioperative period. A critical analysis on data recorded from randomized control trials (RCTs) is essential in identifying patients who may benefit or be harmed by a particular anesthetic. RCTs will also contribute to defining methodologies for future studies on the neuroprotective effects of intravenous anesthetics. PMID:24669972

Economic considerations in the use of inhaled anesthetic agents.

PubMed

Golembiewski, Julie

2010-04-15

To describe the components of and factors contributing to the costs of inhaled anesthesia, basis for quantifying and comparing these costs, and practical strategies for performing pharmacoeconomic analyses and reducing the costs of inhaled anesthetic agents. Inhaled anesthesia can be costly, and some of the variable costs, including fresh gas flow rates and vaporizer settings, are potential targets for cost savings. The use of a low fresh gas flow rate maximizes rebreathing of exhaled anesthetic gas and is less costly than a high flow rate, but it provides less control of the level of anesthesia. The minimum alveolar concentration (MAC) hour is a measure that can be used to compare the cost of inhaled anesthetic agents at various fresh gas flow rates. Anesthesia records provide a sense of patterns of inhaled anesthetic agent use, but the amount of detail can be limited. Cost savings have resulted from efforts to reduce the direct costs of inhaled anesthetic agents, but reductions in indirect costs through shortened times to patient recovery and discharge following the judicious use of these agents are more difficult to demonstrate. The patient case mix, fresh gas flow rates typically used during inhaled anesthesia, availability and location of vaporizers, and anesthesia care provider preferences and practices should be taken into consideration in pharmacoeconomic evaluations and recommendations for controlling the costs of inhaled anesthesia. Understanding factors that contribute to the costs of inhaled anesthesia and considering those factors in pharmacoeconomic analyses and recommendations for use of these agents can result in cost savings.

Incineration or autoclave? A comparative study in isfahan hospitals waste management system (2010).

PubMed

Ferdowsi, Ali; Ferdosi, Masoud; Mehrani, Mohammd Javad

2013-03-01

Medical wastes are among hazardous wastes and their disposal requires special methods prior to landfilling. Medical wastes are divided into infected and non-infected wastes and the infected wastes require treatment. Incineration is one of the oldest methods for treatment of medical wastes, but their usage have faced wide objections due to emission of hazardous gases such as CO2 and CO as well as Carcinogenic gases such as Dioxins and Furans which are generated as a result of incomplete combustion of compositions like PVCs. Autoclave is one the newest methods of medical wastes treatment which works based on wet disinfection. The statistical population in this descriptive, comparative study includes hospitals located in Isfahan city and the sample hospitals were selected randomly. To environmentally evaluate the Autoclave method, TST (time, steam, temperature) and Spore tests were used. Also, samples were made from incinerator's stack gases and their analyses results were compared with WHO standards. TST and spore tests results were negative in all cases indicating the success of treatment process. The comparison of incinerator's stack gases with WHO standards showed the high concentration of CO in some samples indicating the incomplete combustion. Also, the incineration efficiency in some cases was less than 99.5 percent, which is the efficiency criterion according to the administrative regulations of wastes management law of Iran. No needle stick was observed in Autoclave method during the compaction of bags containing wastes, and the handlers were facing no danger in this respect. The comparison of costs indicated that despite higher capital investment for purchasing autoclave, its current costs (e.g. maintenance, etc) are much less than the incineration method. Totally, due to inappropriate operation of incinerators and lack of air pollution control devices, the use of incinerators doesn't seem rational anymore. Yet, despite the inefficiency of autoclaves in

Incineration or Autoclave? A Comparative Study in Isfahan Hospitals Waste Management System (2010)

PubMed Central

Ferdowsi, Ali; Ferdosi, Masoud; Mehrani, Mohammd Javad

2013-01-01

Introduction: Medical wastes are among hazardous wastes and their disposal requires special methods prior to landfilling. Medical wastes are divided into infected and non-infected wastes and the infected wastes require treatment. Incineration is one of the oldest methods for treatment of medical wastes, but their usage have faced wide objections due to emission of hazardous gases such as CO2 and CO as well as Carcinogenic gases such as Dioxins and Furans which are generated as a result of incomplete combustion of compositions like PVCs. Autoclave is one the newest methods of medical wastes treatment which works based on wet disinfection. Methods: The statistical population in this descriptive, comparative study includes hospitals located in Isfahan city and the sample hospitals were selected randomly. To environmentally evaluate the Autoclave method, TST (time, steam, temperature) and Spore tests were used. Also, samples were made from incinerator’s stack gases and their analyses results were compared with WHO standards. Findings: TST and spore tests results were negative in all cases indicating the success of treatment process. The comparison of incinerator’s stack gases with WHO standards showed the high concentration of CO in some samples indicating the incomplete combustion. Also, the incineration efficiency in some cases was less than 99.5 percent, which is the efficiency criterion according to the administrative regulations of wastes management law of Iran. No needle stick was observed in Autoclave method during the compaction of bags containing wastes, and the handlers were facing no danger in this respect. The comparison of costs indicated that despite higher capital investment for purchasing autoclave, its current costs (e.g. maintenance, etc) are much less than the incineration method. Discussion: Totally, due to inappropriate operation of incinerators and lack of air pollution control devices, the use of incinerators doesn’t seem rational anymore

21 CFR 346.16 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 346.16 Section 346.16 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Ingredients § 346.16 Analgesic, anesthetic, and antipruritic active ingredients. The active ingredient of the...

21 CFR 346.16 - Analgesic, anesthetic, and antipruritic active ingredients.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Analgesic, anesthetic, and antipruritic active ingredients. 346.16 Section 346.16 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Ingredients § 346.16 Analgesic, anesthetic, and antipruritic active ingredients. The active ingredient of the...

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, Santi; Kulkarni, Sudhir S.

1986-01-01

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.; Kulkarni, S.S.

1986-08-26

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

The Effect of Heart Disease on Anesthetic Complications During Routine Dental Procedures in Dogs.

PubMed

Carter, Jennifer E; Motsinger-Reif, Alison A; Krug, William V; Keene, Bruce W

Dental procedures are a common reason for general anesthesia, and there is widespread concern among veterinarians that heart disease increases the occurrence of anesthetic complications. Anxiety about anesthetizing dogs with heart disease is a common cause of referral to specialty centers. To begin to address the potential effect of heart disease on anesthetic complications in dogs undergoing anesthesia for routine dental procedures, we compared anesthetic complications in 100 dogs with heart disease severe enough to trigger referral to a specialty center (cases) to those found in 100 dogs without cardiac disease (controls) that underwent similar procedures at the same teaching hospital. Medical records were reviewed to evaluate the occurrence of anesthetic complications. No dogs died in either group, and no significant differences were found between the groups in any of the anesthetic complications evaluated, although dogs in the heart disease group were significantly older with higher American Society of Anesthesiologists scores. Midazolam and etomidate were used more frequently, and alpha-2 agonists used less frequently, in the heart disease group compared to controls. This study suggests dogs with heart disease, when anesthetized by trained personnel and carefully monitored during routine dental procedures, are not at significantly increased risk for anesthetic complications.

Interactions of anesthetics with the membrane-water interface

NASA Technical Reports Server (NTRS)

Pohorille, A.; Cieplak, P.; Wilson, M. A.

1996-01-01

Although the potency of conventional anesthetics correlates with lipophilicity, an affinity to water also is essential. It was recently found that compounds with very low affinities to water do not produce anesthesia regardless of their lipophilicity. This finding implies that clinical anesthesia might arise because of interactions at molecular sites near the interface of neuronal membranes with the aqueous environment and, therefore, might require increased concentrations of anesthetic molecules at membrane interfaces. As an initial test of this hypothesis, we calculated in molecular dynamics simulations the free energy profiles for the transfer of anesthetic 1,1,2-trifluoroethane and nonanesthetic perfluoroethane across water-membrane and water-hexane interfaces. Consistent with the hypothesis, it was found that trifluoroethane, but not perfluoroethane, exhibits a free energy minimum and, therefore, increased concentrations at both interfaces. The transfer of trifluoroethane from water to the nonpolar hexane or interior of the membrane is accompanied by a considerable, solvent-induced shift in the conformational equilibrium around the C-C bond.

Single-Anesthetic Versus Staged Bilateral Total Hip Arthroplasty: A Matched Cohort Study.

PubMed

Houdek, Matthew T; Wyles, Cody C; Watts, Chad D; Wagner, Eric R; Sierra, Rafael J; Trousdale, Robert T; Taunton, Michael J

2017-01-04

There is debate regarding the role of single-anesthetic versus staged bilateral total hip arthroplasty (THA) for patients with end-stage bilateral osteoarthritis. Studies have shown that single-anesthetic bilateral THA is associated with systemic complications, but there are limited data comparing patient outcomes in a matched setting of bilateral THA. We identified 94 patients (188 hips) who underwent single-anesthetic bilateral THA. Fifty-seven percent of the patients were male. Patients had a mean age of 52.2 years and body mass index of 27.1 kg/m. They were matched 1:1 on the basis of sex, age (±1 year), and year of surgery (±3 years) to a cohort of patients undergoing staged bilateral THA. In the staged group, there was <1 year between procedures (range, 5 days to 10 months). Mean follow-up was 4 years for each group. Patients in the single-anesthetic group experienced shorter total operating room time and length of stay. There was no difference (hazard ratio [HR] = 0.73, p = 0.50) in the overall revision-free survival in patients undergoing single-anesthetic or staged bilateral THA. The risks of reoperation (HR = 0.69, p = 0.40), complications (HR = 0.83, p = 0.48), and mortality (HR = 0.47, p = 0.10) were similar. Single-anesthetic bilateral THA reduced the total cost of care (by 27%, p = 0.0001). In this matched cohort analysis, single-anesthetic bilateral THA was not associated with an increased risk of revision, reoperation, or postoperative complications, while decreasing cost. In our experience, single-anesthetic bilateral THA is a safe procedure that, for certain patients, offers an excellent means to deal with bilateral hip osteoarthritis. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Urethane inhibits genioglossal long-term facilitation in un-paralyzed anesthetized rats.

PubMed

Cao, Ying; Ling, Liming

2010-06-25

For approximately 3 decades, urethane has been (partially or solely) used as a successful anesthetic in numerous respiratory long-term facilitation (LTF) studies, which were performed on anesthetized, paralyzed, vagotomized and artificially ventilated animals of several different species. However, things become complicated when LTF of muscle activity is studied in un-paralyzed animals. For example, a commonly used acute intermittent hypoxia (AIH) protocol failed to induce muscle LTF in anesthetized, spontaneously breathing rats. But muscle LTF could be induced when hypoxic episode number was increased and/or anesthetics other than urethane were used. In these studies however, neither anesthetic nor paralysis was mentioned as a potential factor influencing AIH-induced muscle LTF. This study tested whether urethane inhibits AIH-induced genioglossal LTF (gLTF) in un-paralyzed ventilated rats, and if so, determined whether reducing urethane dose reverses this inhibition. Three groups of adult male Sprague-Dawley rats were anesthetized (Group 1: approximately 1.6 g kg(-1) urethane; Group 2: 50 mg kg(-1) alpha-chloralose +0.9-1.2 g kg(-1) urethane; Group 3: 0.9 g kg(-1) urethane +200-400 microg kg(-1) min(-1) alphaxalone), vagotomized and mechanically ventilated. Integrated genioglossus activity was measured before, during and after AIH (5 episodes of 3-min isocapnic 12% O(2), separated by 3-min hyperoxic intervals). The AIH-induced gLTF was absent in Group 1 rats (success rate was only approximately 1/7), but was present in Group 2 (in 10/12 rats) and Group 3 (in 11/11 rats) rats. The genioglossal response to hypoxia was not significantly different among the 3 groups. Collectively, these data suggest that urethane dose-dependently inhibits gLTF in un-paralyzed anesthetized rats. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

High Resolution Features from Low Affinity Interactions: Photoactive Analogs of the Haloether Anesthetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xi,J.; Liu, R.; Rossi, M.

2006-01-01

The difficulty in obtaining binding target and site information for low-affinity drugs, like the inhaled anesthetics, has limited identification of their molecular effectors. Because such information can be provided by photoactive analogues, we designed, synthesized, and characterized a novel diazirnyl haloether that closely mimics isoflurane, the most widely used clinical general anesthetic. This compound, H-diaziflurane, is a nontoxic, potent anesthetic that potentiates GABA-gated ion channels in primary cultures of hippocampal neurons. Calorimetric and structural characterizations show that H-diaziflurane binds a model anesthetic host protein with similar energetics as isoflurane and forms photoadducts with residues lining the isoflurane binding site. H-diazifluranemore » will be immediately useful for identifying targets and sites important for the molecular pharmacology of the inhaled haloether anesthetics.« less

Topical anesthetic abuse keratitis secondary to floppy eyelid syndrome.

PubMed

Goldich, Yakov; Zadok, David; Avni, Isaac; Hartstein, Morris

2011-01-01

To report the diagnosis and management of a patient with chronic ophthalmic topical anesthetic abuse and floppy eyelid syndrome. We describe the case of a 47-year-old man suffering from persistent bilateral ocular irritation and chronic corneal erosions. The patient was hospitalized in our ophthalmology department and underwent thorough ophthalmic, systemic, and psychiatric evaluation. Chronic topical anesthetic abuse was discovered. Removal of abused drops and copious lubricating treatment lead to partial improvement further permitting diagnosis of floppy eyelid syndrome. Definitive surgical treatment by horizontal eyelid tightening combined with continuous lubrication resulted in remission of symptoms. Uncommon conditions may coexist in 1 patient. In this case, floppy eyelid syndrome resulted in topical anesthetic abuse. Ophthalmologists should keep both these conditions in mind when treating patients with otherwise unexplained chronic persistent corneal erosions.

[Emission and control of gases and odorous substances from animal housing and manure depots].

PubMed

Hartung, J

1992-02-01

Agricultural animal production in increasingly regarded as a source of gases which are both aggravating and ecologically harmful. An overview of the origin, number and quantity of trace gases emitted from animal housing and from manure stores is presented and possible means of preventing or reducing them are discussed. Of the 136 trace gases in the air of animal houses, odorous substances, ammonia and methane are most relevant to the environment. The role played by the remaining gases is largely unknown. Quantitative information is available for 23 gases. The gases are emitted principally from freshly deposited and stored faeces, from animal feed and from the animals themselves. Future work should determine sources and quantities of the gases emitted from animal housing more precisely and should aim to investigate the potential of these gases to cause damage in man, animals and environment. Odorous substances have an effect on the area immediately surrounding the animal housing. They can lead to considerable aggravation in humans. For years, VDI1 guidelines (3471/72), which prescribe distances between residential buildings and animal housing, have been valuable in preventing odour problems of this kind. Coverings are suitable for outside stores. The intensity of the odour from animal housing waste air increases from cattle through to hens and pigs; it is also further affected by the type of housing, the age of the animals and the purpose for which they are being kept. Methods of cleaning waste air (scrubbers/biofilters) are available for problematic cases. The need for guidelines to limit emissions from individual outside manure stores (lagoons) is recognised. Total ammonia emissions from animal production in the Federal Republic of Germany (up to 1989) are estimated at approximately 300,000 to 600,000 t/year. There is a shortage of satisfactory and precise research on the extent of emissions, in particular on those from naturally ventilated housing. It is

Effectiveness of 20% benzocaine as a topical anesthetic for intraoral injections.

PubMed Central

Nusstein, John M.; Beck, Mike

2003-01-01

The use of topical anesthetics has been advocated prior to the administration of various types of anesthetic injections. Reported results have varied between studies. The purpose of this study was to compare the effectiveness of 20% benzocaine in reducing the pain of needle insertion during maxillary posterior and anterior infiltration and inferior alveolar nerve block injections. In this retrospective study, 1080 patients received 2336 injections using a 27-gauge needle. Topical anesthetic was applied prior to 720 of the injections. Patients rated pain of needle insertion using a 0-4 pain scale. Logistic regression analysis showed no differences in pain ratings between topical and no topical groups for the inferior alveolar nerve block and posterior maxillary infiltration injections. The use of topical anesthetic did reduce the pain of needle insertion with the maxillary anterior injections (P = .0041). PMID:14959903

Health effects associated with exposure to anaesthetic gases in Ontario hospital personnel.

PubMed Central

Guirguis, S S; Pelmear, P L; Roy, M L; Wong, L

1990-01-01

In a retrospective study (by questionnaire) of 8032 personnel exposed to anaesthetic gases in operating and recovery rooms in Ontario hospitals, and 2525 non-exposed hospital staff, the response was 78.8% for the exposed and 87.2% for the unexposed personnel during the period 1981-5. Logistic regression analysis, with age and smoking standardised, showed that women in the exposed group had significantly increased frequencies of spontaneous abortion and their children had significantly more congenital abnormalities (p less than 0.05). No chronic disease was significantly associated with the exposed group. These findings, together with similar ones from other studies, suggest that it is prudent to minimise exposure to waste anaesthetic gases. PMID:2383519

ACCURACY OF NONINVASIVE ANESTHETIC MONITORING IN THE ANESTHETIZED GIRAFFE (GIRAFFA CAMELOPARDALIS).

PubMed

Bertelsen, Mads F; Grøndahl, Carsten; Stegmann, George F; Sauer, Cathrine; Secher, Niels H; Hasenkam, J Michael; Damkjær, Mads; Aalkjær, Christian; Wang, Tobias

2017-09-01

This study evaluated the accuracy of pulse oximetry, capnography, and oscillometric blood pressure during general anesthesia in giraffes (Giraffa camelopardalis). Thirty-two giraffes anesthetized for physiologic experiments were instrumented with a pulse oximeter transmittance probe positioned on the tongue and a capnograph sampling line placed at the oral end of the endotracheal tube. A human size 10 blood pressure cuff was placed around the base of the tail, and an indwelling arterial catheter in the auricular artery continuously measured blood pressure. Giraffes were intermittently ventilated using a Hudson demand valve throughout the procedures. Arterial blood for blood gas analysis was collected at multiple time points. Relationships between oxygen saturation as determined by pulse oximetry and arterial oxygen saturation, between arterial carbon dioxide partial pressure and end-tidal carbon dioxide, and between oscillometric pressure and invasive arterial blood pressure were assessed, and the accuracy of pulse oximetry, capnography, and oscillometric blood pressure monitoring evaluated using Bland-Altman analysis. All three noninvasive methods provided relatively poor estimates of the reference values. Receiver operating characteristic curve fitting was used to determine cut-off values for hypoxia, hypocapnia, hypercapnia, and hypotension for dichotomous decision-making. Applying these cut-off values, there was reasonable sensitivity for detection of hypocapnia, hypercapnia, and hypotension, but not for hypoxemia. Noninvasive anesthetic monitoring should be interpreted with caution in giraffes and, ideally, invasive monitoring should be employed.

Anesthetic synergy between two n-alkanes.

PubMed

Brosnan, Robert J; Fukushima, Fabíola B; Pham, Trung L

2017-05-01

N-butane and n-pentane can both produce general anesthesia. Both compounds potentiate γ-aminobutyric acid type A (GABA A ) receptor function, but only butane inhibits N-methyl-d-aspartate (NMDA) receptors. It was hypothesized that butane and pentane would exhibit anesthetic synergy due to their different actions on ligand-gated ion channels. Prospective experimental study. A total of four Xenopus laevis frogs and 43 Sprague-Dawley rats. Alkane concentrations for all studies were determined via gas chromatography. Using a Xenopus oocyte expression model, standard two-electrode voltage clamp techniques were used to measure NMDA and GABA A receptor responses in vitro as a function of butane and pentane concentrations relevant to anesthesia. The minimum alveolar concentrations (MAC) of butane and pentane were measured separately in rats, and then pentane MAC was measured during coadministration of 0.25, 0.50 or 0.75 times MAC of butane. An isobole with 95% confidence intervals was constructed using regression analysis. A sum of butane and pentane that was statistically less than the lower-end confidence bound isobole indicated a synergistic interaction. Both butane and pentane dose-dependently potentiated GABA A receptor currents over the study concentration range. Butane dose-dependently inhibited NMDA receptor currents, but pentane did not modulate NMDA receptors. Butane and pentane MAC in rats was 39.4±0.7 and 13.7±0.4 %, respectively. A small but significant (p<0.03) synergistic anesthetic effect with pentane was observed during administration of either 0.50 or 0.75×MAC butane. Butane and pentane show synergistic anesthetic effects in vivo consistent with their different in vitro receptor effects. Findings support the relevance of NMDA receptors in mediating anesthetic actions for some, but not all, inhaled agents. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd

Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 curvemore » 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.« less

Best anesthetics for assessing left ventricular systolic function by echocardiography in mice

PubMed Central

Pachon, Ronald E.; Scharf, Bruce A.; Vatner, Dorothy E.

2015-01-01

Our review of the literature of the major cardiovascular journals for the past three years showed that for all studies using anesthesia for mouse echocardiography, the predominant anesthetic was isoflurane, which was used in 76% of the studies. The goal of this investigation was to determine if isoflurane is indeed the best anesthetic. Accordingly, we compared isoflurane with 2,2,2-tribromoethanol (Avertin), ketamine-xylazine, and ketamine on different days in the same 14 mice, also studied in the conscious state without anesthesia. A randomized crossover study design was employed to compare the effects on left ventricular (LV) systolic function and heart rate of the four different anesthetic agents assessed by transthoracic echocardiography. As expected, each anesthetic depressed LV ejection fraction and heart rate when compared with values in conscious mice. Surprisingly, isoflurane was not the best, but actually second to last in maintaining normal LV function and heart rate. The anesthetic with the least effect on LV function and heart rate was ketamine alone at a dose of 150 mg/kg, followed by Avertin at 290 mg/kg, isoflurane at 3% induction and 1 to 2% maintenance, and lastly ketamine-xylazine at 100 and 10 mg/kg, respectively. In summary, these results indicate that ketamine alone exerts the least depressant effects on LV function and heart rate, with Avertin second, suggesting that these anesthetics should be used when it is not feasible to study the animals in the conscious state as opposed to the most commonly used anesthetic, isoflurane. PMID:25862835

Best anesthetics for assessing left ventricular systolic function by echocardiography in mice.

PubMed

Pachon, Ronald E; Scharf, Bruce A; Vatner, Dorothy E; Vatner, Stephen F

2015-06-15

Our review of the literature of the major cardiovascular journals for the past three years showed that for all studies using anesthesia for mouse echocardiography, the predominant anesthetic was isoflurane, which was used in 76% of the studies. The goal of this investigation was to determine if isoflurane is indeed the best anesthetic. Accordingly, we compared isoflurane with 2,2,2-tribromoethanol (Avertin), ketamine-xylazine, and ketamine on different days in the same 14 mice, also studied in the conscious state without anesthesia. A randomized crossover study design was employed to compare the effects on left ventricular (LV) systolic function and heart rate of the four different anesthetic agents assessed by transthoracic echocardiography. As expected, each anesthetic depressed LV ejection fraction and heart rate when compared with values in conscious mice. Surprisingly, isoflurane was not the best, but actually second to last in maintaining normal LV function and heart rate. The anesthetic with the least effect on LV function and heart rate was ketamine alone at a dose of 150 mg/kg, followed by Avertin at 290 mg/kg, isoflurane at 3% induction and 1 to 2% maintenance, and lastly ketamine-xylazine at 100 and 10 mg/kg, respectively. In summary, these results indicate that ketamine alone exerts the least depressant effects on LV function and heart rate, with Avertin second, suggesting that these anesthetics should be used when it is not feasible to study the animals in the conscious state as opposed to the most commonly used anesthetic, isoflurane. Copyright © 2015 the American Physiological Society.

Emission and Sink of Greenhouse Gases in Soils of Moscow

NASA Astrophysics Data System (ADS)

Mozharova, N. V.; Kulachkova, S. A.; Lebed'-Sharlevich, Ya. I.

2018-03-01

The first inventory and zoning of the emission and sink of methane and carbon dioxide in the urban structure of greenhouse gases from soils and surface technogenic formations (STFs) (Technosols) on technogenic, recrementogenic, and natural sediments have been performed with consideration for the global warming potential under conditions of different formation rate of these gases, underflooding, and sealing. From gas geochemical criteria and anthropogenic pedogenesis features, the main sources of greenhouse gases, their intensity, and mass emission were revealed. The mass fractions of emissions from the sectors of waste and land use in the inventories of greenhouse gas emissions have been determined. New sources of gas emission have been revealed in the first sector, the emissions from which add tens of percent to the literature and state reports. In the second sector, emissions exceed the available data in 70 times. Estimation criteria based on the degree of manifestation and chemical composition of soil-geochemical anomalies and barrier capacities have been proposed. The sink of greenhouse gases from the atmosphere and the internal (latent) sink of methane in soils and STFs have been determined. Ecological functions of soils and STFs have been shown, and the share of latent methane sink has been calculated. The bacterial oxidation of methane in soils and STFs exceeds its emission to the atmosphere in almost hundred times.

Cortico-centric effects of general anesthetics on cerebrocortical evoked potentials.

PubMed

Voss, Logan J; Sleigh, James W

2015-12-01

Despite their ubiquitous use for rendering patients unconscious for surgery, our understanding of how general anesthetics cause hypnosis remains rudimentary at best. Recent years have seen increased interest in "top-down" cortico-centric theories of anesthetic action. The aim of this study was to explore this by investigating direct cortical effects of anesthetics on cerebrocortical evoked potentials in isolated mouse brain slices. Evoked potentials were elicited in cortical layer IV by electrical stimulation of the underlying white matter. The effects of three anesthetics (ketamine, etomidate, and isoflurane) on the amplitude, latency, and slope of short-latency evoked potentials were quantified. The N2/P3/N4 potentials–which represent the early cortical response–were enhanced by etomidate (increased P3-N4 slope, P <0.01), maintained by ketamine, and reduced by isoflurane (lower N2/P3 amplitude, P <0.01). These effects closely resemble those seen in vivo for the same drugs and point to a cortical mechanism independent of effects on subcortical structures such as the thalamus.

An oil-based model of inhalation anesthetic uptake and elimination.

PubMed

Loughlin, P J; Bowes, W A; Westenskow, D R

1989-08-01

An oil-based model was developed as a physical simulation of inhalation anesthetic uptake and elimination. It provides an alternative to animal models in testing the performance of anesthesia equipment. A 7.5-1 water-filled manometer simulates pulmonary mechanics. Nitrogen and carbon dioxide flowing into the manometer simulate oxygen consumption and carbon dioxide production. Oil-filled chambers (180 ml and 900 ml) simulate the uptake and washout of halothane by the vessel-rich and muscle tissue groups. A 17.2-1 air-filled chamber simulates uptake by the lung group. Gas circulates through the chambers (3.7, 13.8, and 25 l/min) to simulate the transport of anesthetic to the tissues by the circulatory system. Results show that during induction and washout, the rate of rise in endtidal halothane fraction simulated by the model parallels that measured in patients. The model's end-tidal fraction changes correctly with changes in cardiac output and alveolar ventilation. The model has been used to test anesthetic controllers and to evaluate gas sensors, and should be useful in teaching principles underlying volatile anesthetic uptake.

Flavored Anesthetic Masks for Inhalational Induction in Children.

PubMed

Gupta, Aakriti; Mathew, Preethy Joseph; Bhardwaj, Neerja

2017-10-01

To evaluate the clinical efficacy of masking the odor of inhalational agents using fruit flavors on the anxiety behavior and compliance of children for inhalational induction. A prospective randomized double blind, placebo controlled study was conducted on 60 unpremedicated children in the age group of 4-12 y. Thirty children received anesthetic masks smeared with a flavor of child's choice while the other 30 children were induced using masks without flavor. Anxiety was assessed using modified Yale Pre-operative Anxiety Scale (mYPAS) in the pre-op room and during inhalational induction. Mask acceptance was graded by Induction Compliance Checklist (ICC). The cost-effectiveness of flavored anesthetic masks was compared to that of commercially available pre-scented masks. The baseline anxiety in the two groups was comparable. The number of children demonstrating high levels of anxiety at anesthetic induction was similar in flavored and non-flavored mask groups (p 0.45). The compliance to mask induction was also equally good (p 0.99). The authors found significant difference in the cost of flavored mask (INR 56.45 per mask) as compared to commercially available pre-scented masks (INR 660 per mask). The authors observed a placebo effect that reduced the pre-op anxiety in the control group which probably made the quality of induction equivalent with flavored and non-flavored masks. Therefore, using a flavored anesthetic mask is cost-effective than using a commercially available pre-scented mask.

High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biganzoli, Laura, E-mail: laura.biganzoli@mail.polimi.it; Racanella, Gaia; Marras, Roberto

Highlights: • Two scenarios of acid gases removal in WTE plants were compared in an LCA study. • A detailed inventory based on primary data has been reported for the production of the new dolomitic sorbent. • Results show that the comparison between the two scenarios does not show systematic differences. • The potential impacts are reduced only if there is an increase in the energy efficiency of the WTE plant. - Abstract: The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminarymore » stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO{sub 2} emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests

Anesthetics mechanism on a DMPC lipid membrane model: Insights from molecular dynamics simulations.

PubMed

Saeedi, Marzieh; Lyubartsev, Alexander P; Jalili, Seifollah

2017-07-01

To provide insight into the molecular mechanisms of local anesthetic action, we have carried out an extensive investigation of two amide type local anesthetics, lidocaine and articaine in both charged and uncharged forms, interacting with DMPC lipid membrane. We have applied both standard molecular dynamics simulations and metadynamics simulations to provide a detailed description of the free energy landscape of anesthetics embedded in the lipid bilayer. The global minimum of the free energy surface (equilibrium position of anesthetics in the lipid membrane) occurred around 1nm of the bilayer center. The uncharged anesthetics show more affinity to bind to this region compared to the charged drugs. The binding free energy of uncharged lidocaine in the membrane (-30.3kJ/mol) is higher than uncharged articaine (-24.0kJ/mol), which is in good agreement with higher lipid solubility of lidocaine relative to the articaine. The octanol/water partition coefficient of uncharged drugs was also investigated using expanded ensemble simulations. In addition, complementary standard MD simulations were carried out to study the partitioning behavior of multiple anesthetics inside the lipid bilayer. The results obtained here are in line with previously reported simulations and suggest that the different forms of anesthetics induce different structural modifications in the lipid bilayer, which can provide new insights into their complex membrane translocation phenomena. Copyright © 2017 Elsevier B.V. All rights reserved.

Procedures for making gaseous industrial waste safe

NASA Astrophysics Data System (ADS)

Matros, Yu Sh; Noskov, Aleksandr S.

1990-10-01

The application of various methods (adsorption, absorption, thermal afterburning, catalytic purification, and others) for the removal of sulphur and nitrogen oxides, toxic organic compounds, hydrogen sulphide, and carbon monoxide from industrial waste gases is described. Much attention is devoted to the catalytic procedure for making the gases safe using an energy collecting non-stationary method (reversible process). The advantages and limitations of various gas purification methods are considered. The bibliography includes 279 references.

Autonomic cardiovascular modulation with three different anesthetic strategies during neurosurgical procedures.

PubMed

Guzzetti, S; Bassani, T; Latini, R; Masson, S; Barlera, S; Citerio, G; Porta, A

2015-01-01

Autonomic cardiovascular modulation during surgery might be affected by different anesthetic strategies. Aim of the present study was to assess autonomic control during three different anesthetic strategies in the course of neurosurgical procedures by the linear and non-linear analysis of two cardiovascular signals. Heart rate (EKG-RR intervals) and systolic arterial pressure (SAP) signals were analyzed in 93 patients during elective neurosurgical procedures at fixed points: anesthetic induction, dura mater opening, first and second hour of surgery, dura mater and skin closure. Patients were randomly assigned to three anesthetic strategies: sevoflurane+fentanyl (S-F), sevoflurane+remifentanil (S-R) and propofol+remifentanil (P-R). All the three anesthetic strategies were characterized by a reduction of RR and SAP variability. A more active autonomic sympathetic modulation, as ratio of low to high frequency spectral components of RR variability (LF/HF), was present in the P-R group vs. S-R group. This is confirmed by non-linear symbolic analysis of RR series and SAP variability analysis. In addition, an increased parasympathetic modulation was suggested by symbolic analysis of RR series during the second hour of surgery in S-F group. Despite an important reduction of cardiovascular signal variability, the analysis of RR and SAP signals were capable to detect information about autonomic control during anesthesia. Symbolic analysis (non-linear) seems to be able to highlight the differences of both the sympathetic (slow) and vagal (fast) modulation among anesthetics, while spectral analysis (linear) underlines the same differences but only in terms of balance between the two neural control systems.

Hazardous Waste Management Systems: Identification and Listing of Hazardous Waste - Federal Register Notice, May 1, 1991

EPA Pesticide Factsheets

The EPA is announcing an administrative stay of a portion of the hazardous waste listing K069 so that the listing does not apply to slurries generated from air pollution control devices that are intended to capture acid gases.

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

PubMed Central

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

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

PubMed

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.

Influence of volatile anesthetics on muscarinic receptor adenylate cyclase coupling in brain and heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthony, B.L.

In the present study, the influence of four volatile anesthetics (enflurane, isoflurane, diethyl ether, and chloroform) on (1) muscarinic receptor binding parameters and (2) muscarnic regulation of adenylate cyclase activity was examined using membranes isolated from rat brain and heart. Membranes were equilibrated with each of the four anesthetics for 30 minutes and then during the binding assay. The data obtained can be summarized as follows: (1) volatile anesthetics increased receptor affinity for a radiolabeled antagonists, ({sup 3}H)N-methylscopolamine (({sup 3}H)MS), by decreasing its rate of dissociation in brain stem, but not in cardiac, membranes, (2) volatile anesthetics decreased high affinitymore » ({sup 3}H)Oxotremorine-M binding, (3) volatile anesthetics depressed or eliminated the guanine nucleotide sensitivity of agonist binding. The influence of volatile anesthetics on muscarinic regulation of adenylate cyclase enzyme activity was studied using {alpha}({sup 32}P)ATP as the substrate.« less

75 FR 876 - Anesthetic and Life Support Drugs Advisory Committee; Cancellation

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-06

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2009-N-0664] Anesthetic and Life Support Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Anesthetic and Life Support Drugs Advisory Committee...

Local Toxicity from Local Anesthetic Polymeric Microparticles

PubMed Central

McAlvin, J. Brian; Reznor, Gally; Shankarappa, Sahadev A.; Stefanescu, Cristina F.; Kohane, Daniel S.

2013-01-01

Background Local tissue injury from sustained release formulations for local anesthetics can be severe. There is considerable variability in reporting of that injury. We investigated the influence of the intrinsic myotoxicity of the encapsulated local anesthetic (lidocaine, low; bupivacaine, high) on tissue reaction in rats. Methods Cytotoxicity from a range of lidocaine and bupivacaine concentrations was measured in C2C12 myotubes over 6 days. Rats were given sciatic nerve blocks with 4 microparticulate formulations of lidocaine and bupivacaine: 10% (w/w) lidocaine poly-lactic-co-glycolic acid (PLGA), 10% (w/w) bupivacaine PLGA, 50% (w/w) lidocaine PLGA, and 50% (w/w) bupivacaine PLGA. Effectiveness of nerve blockade was assessed by a modified hotplate test and weight-bearing measurements. Myotoxicity was scored in histologic sections of injection sites. Bupivacaine and lidocaine release kinetics from the particles were measured. Results Median sensory blockade duration for 50% (w/w) lidocaine was 255 (90–540) min versus 840 (277–1215) min for 50% (w/w) bupivacaine (P=0.056). All microparticulate formulations resulted in myotoxicity. The choice of local anesthetic did not influence the severity of myotoxicity. Median myotoxicity scores for 50% (w/w) lidocaine compared to 50% (w/w) bupivacaine at 4 days was 3.4 (2.1–4.2) vs. 3.3 (2.9–3.5)(P=0.44) and at 14 days 1.9 (1.8–2.4) versus 1.7 (1.3–1.9)(P=0.23) respictively. Conclusions Lidocaine and bupivacaine PLGA microspheres resulted in similar degrees of myotoxicity, irrespective of drug loading. Intrinsic myotoxicity did not predict tissue injury from sustained release of these anesthetics. Caution is warranted in the use of such devices near muscle and nerve. PMID:23460564

Effects of anesthetic agents on in vivo axonal HCN current in normal mice.

PubMed

Osaki, Yusuke; Nodera, Hiroyuki; Banzrai, Chimeglkham; Endo, Sachiko; Takayasu, Hirokazu; Mori, Atsuko; Shimatani, Yoshimitsu; Kaji, Ryuji

2015-10-01

The objective was to study the in vivo effects of anesthetic agents on peripheral nerve excitability. Normal male mice were anesthetized by either isoflurane inhalation or a combination of medetomidine, midazolam, and butorphanol intraperitoneal injection ("triple agents"). Immediately after induction, the tail sensory nerve action potential was recorded and its excitability was monitored. Under both anesthetic protocols, there was an interval excitability change by long hyperpolarizing currents. There was greater threshold reduction approximately 30min post induction, in comparison to immediately post induction. Other excitability parameters were stable over time. Modeling suggested interval suppression of internodal H conductance or leak current. Anesthetic agents affected responses to long hyperpolarizing currents. Axonal excitability during intraoperative monitoring may be affected by anesthetic agents. Interpretation of interval excitability changes under anesthesia requires caution, especially with long hyperpolarizing currents. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Update on administration of anesthetics and psychoactive drugs for pain management in China.

PubMed

Gu, Weiping

2015-06-01

Anesthetics and psychoactive drugs could relieve diseases, if used properly. However, they can cause dependency, and their misuse or abuse could adversely affect people's health and social stability. For a long time, the Chinese government has been reinforcing the regulation on anesthetics and psychoactive drugs to ensure their legal and proper usage, and to prevent abuse. The state council issued 'the regulations on the administration of anesthetic drugs and psychotropic drugs' in 2005, based on which a legal system was established for administration of anesthetics and psychoactive drugs with the objectives of ensuring their legitimate medical utilization, and preventing illegal abuse. Copyright © 2015. Published by Elsevier B.V.

Landfilling of waste: accounting of greenhouse gases and global warming contributions.

PubMed

Manfredi, Simone; Tonini, Davide; Christensen, Thomas H; Scharff, Heijo

2009-11-01

Accounting of greenhouse gas (GHG) emissions from waste landfilling is summarized with the focus on processes and technical data for a number of different landfilling technologies: open dump (which was included as the worst-case-scenario), conventional landfills with flares and with energy recovery, and landfills receiving low-organic-carbon waste. The results showed that direct emissions of GHG from the landfill systems (primarily dispersive release of methane) are the major contributions to the GHG accounting, up to about 1000 kg CO(2)-eq. tonne( -1) for the open dump, 300 kg CO(2)-eq. tonne( -1) for conventional landfilling of mixed waste and 70 kg CO(2)-eq. tonne(-1) for low-organic-carbon waste landfills. The load caused by indirect, upstream emissions from provision of energy and materials to the landfill was low, here estimated to be up to 16 kg CO(2)-eq. tonne(-1). On the other hand, utilization of landfill gas for electricity generation contributed to major savings, in most cases, corresponding to about half of the load caused by direct GHG emission from the landfill. However, this saving can vary significantly depending on what the generated electricity substitutes for. Significant amounts of biogenic carbon may still be stored within the landfill body after 100 years, which here is counted as a saved GHG emission. With respect to landfilling of mixed waste with energy recovery, the net, average GHG accounting ranged from about -70 to 30 kg CO(2)-eq. tonne(- 1), obtained by summing the direct and indirect (upstream and downstream) emissions and accounting for stored biogenic carbon as a saving. However, if binding of biogenic carbon was not accounted for, the overall GHG load would be in the range of 60 to 300 kg CO(2)-eq. tonne( -1). This paper clearly shows that electricity generation as well as accounting of stored biogenic carbon are crucial to the accounting of GHG of waste landfilling.

Local anesthetics disrupt energetic coupling between the voltage-sensing segments of a sodium channel.

PubMed

Muroi, Yukiko; Chanda, Baron

2009-01-01

Local anesthetics block sodium channels in a state-dependent fashion, binding with higher affinity to open and/or inactivated states. Gating current measurements show that local anesthetics immobilize a fraction of the gating charge, suggesting that the movement of voltage sensors is modified when a local anesthetic binds to the pore of the sodium channel. Here, using voltage clamp fluorescence measurements, we provide a quantitative description of the effect of local anesthetics on the steady-state behavior of the voltage-sensing segments of a sodium channel. Lidocaine and QX-314 shifted the midpoints of the fluorescence-voltage (F-V) curves of S4 domain III in the hyperpolarizing direction by 57 and 65 mV, respectively. A single mutation in the S6 of domain IV (F1579A), a site critical for local anesthetic block, abolished the effect of QX-314 on the voltage sensor of domain III. Both local anesthetics modestly shifted the F-V relationships of S4 domain IV toward hyperpolarized potentials. In contrast, the F-V curve of the S4 domain I was shifted by 11 mV in the depolarizing direction upon QX-314 binding. These antagonistic effects of the local anesthetic indicate that the drug modifies the coupling between the voltage-sensing domains of the sodium channel. Our findings suggest a novel role of local anesthetics in modulating the gating apparatus of the sodium channel.

Alfaxalone as an intramuscular injectable anesthetic in koi carp (Cyprinus carpio).

PubMed

Bailey, Kate M; Minter, Larry J; Lewbart, Gregory A; Harms, Craig A; Griffith, Emily H; Posner, Lysa P

2014-12-01

Fish are commonly anesthetized with MS-222 (tricaine methanesulfonate), a sodium-channel-blocker used as an immersion anesthetic, but its mechanism of action as a general anesthetic is uncertain. Alfaxalone is a neurosteroid that acts at the GABA(A) receptors. Alfaxalone has been evaluated and was deemed successful as an immersion agent in koi carp. Alfaxalone is an effective intramuscular anesthetic in multiple species. A reliable intramuscular anesthetic in fish would be useful in multiple settings. The purpose of this study was to investigate alfaxalone as an intramuscular injectable anesthetic agent in koi carp (Cyprinus carpio). Eight koi carp were utilized in a crossover design. In each trial, six fish received 1 mg/kg, 5 mg/kg, or 10mg/kg of alfaxalone intramuscularly. They were assessed every 15 min for opercular rate and sedation score. The sedation score was based on a visual scale from 0 to 5, 0 indicating no response and 5 indicating absent righting reflex and anesthesia. Anesthetized koi were placed on a fish anesthesia delivery system (FADS). Time to anesthesia/recovery was recorded and heart rate was recorded every 15 min. Anesthesia was achieved in 0/6, 1/6, and 5/6 fish at 1, 5, and 10 mg/kg, respectively. Duration of anesthesia for one fish at 5 mg/kg was 2 hr. At 10 mg/kg, median anesthesia duration was 6.5 (3-10) hr. At 10 mg/kg, prolonged apnea (2-3 hr) was observed in 3/6 fish, 2/3 died under anesthesia, and 1/3 recovered 10 hr post-injection. Median peak sedation scores were 1.5, 2.5, and 5, at 1, 5, and 10 mg/kg, respectively. A dosage of 10 mg/kg alfaxalone resulted in 33% mortality. The duration of anesthesia and opercular rate were unpredictable. Due to variation in response despite consistent conditions, as well as risk of mortality, intramuscular alfaxalone cannot be recommended for anesthesia in koi carp.

Binding of volatile anesthetics to serum albumin: measurements of enthalpy and solvent contributions.

PubMed

Sawas, Abdul H; Pentyala, Srinivas N; Rebecchi, Mario J

2004-10-05

This study directly examines the enthalpic contributions to binding in aqueous solution of closely related anesthetic haloethers (desflurane, isoflurane, enflurane, and sevoflurane), a haloalkane (halothane), and an intravenous anesthetic (propofol) to bovine and human serum albumin (BSA and HSA) using isothermal titration calorimetry. Binding to serum albumin is exothermic, yielding enthalpies (DeltaH(obs)) of -3 to -6 kcal/mol for BSA with a rank order of apparent equilibrium association constants (K(a) values): desflurane > isoflurane approximately enflurane > halothane >or= sevoflurane, with the differences being largely ascribed to entropic contributions. Competition experiments indicate that volatile anesthetics, at low concentrations, share the same sites in albumin previously identified in crystallographic and photo-cross-linking studies. The magnitude of the observed DeltaH increased linearly with increased reaction temperature, reflecting negative changes in heat capacities (DeltaC(p)). These -DeltaC(p) values significantly exceed those calculated for burial of each anesthetic in a hydrophobic pocket. The enhanced stabilities of the albumin/anesthetic complexes and -DeltaC(p) are consistent with favorable solvent rearrangements that promote binding. This idea is supported by substitution of D(2)O for H(2)O that significantly reduces the favorable binding enthalpy observed for desflurane and isoflurane, with an opposing increase of DeltaS(obs). From these results, we infer that solvent restructuring, resulting from release of water weakly bound to anesthetic and anesthetic-binding sites, is a dominant and favorable contributor to the enthalpy and entropy of binding to proteins.

Structural Basis for High Affinity Volatile Anesthetic Binding in a Natural 4-helix Bundle Protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu,R.; Loll, P.; Eckenhoff, R.

2005-01-01

Physiologic sites for inhaled anesthetics are presumed to be cavities within transmembrane 4-{alpha}-helix bundles of neurotransmitter receptors, but confirmation of binding and structural detail of such sites remains elusive. To provide such detail, we screened soluble proteins containing this structural motif, and found only one that exhibited evidence of strong anesthetic binding. Ferritin is a 24-mer of 4-{alpha}-helix bundles; both halothane and isoflurane bind with K{sub A} values of {approx}10{sup 5} M{sup -1, } higher than any previously reported inhaled anesthetic-protein interaction. The crystal structures of the halothane/apoferritin and isoflurane/apoferritin complexes were determined at 1.75 Angstroms resolution, revealing a commonmore » anesthetic binding pocket within an interhelical dimerization interface. The high affinity is explained by several weak polar contacts and an optimal host/guest packing relationship. Neither the acidic protons nor ether oxygen of the anesthetics contribute to the binding interaction. Compared with unliganded apoferritin, the anesthetic produced no detectable alteration of structure or B factors. The remarkably high affinity of the anesthetic/apoferritin complex implies greater selectivity of protein sites than previously thought, and suggests that direct protein actions may underlie effects at lower than surgical levels of anesthetic, including loss of awareness.« less

Increasing topical anesthetic efficacy with microneedle application.

PubMed

Buhsem, Ömer; Aksoy, Alper; Kececi, Yavuz; Sir, Emin; Güngör, Melike

2016-10-01

Since topical anesthetics alone seldom provide adequate analgesia for laser resurfacing procedures, injectable forms of anesthesia are often required. However, their application is uncomfortable for the patient. In this study, it is investigated whether microneedle application would enhance the efficacy of topical anesthetics. Forty-seven patients participated in the study. Topical anesthetic agent EMLA was applied to the whole face of the patients. Microneedle treatment was applied to one side of the face with a roller-type device. Whole-face carbon dioxide laser resurfacing therapy was carried out then. The pain that patients experienced was assessed by using visual analog scale (VAS) method. VAS scores of two sides of the face were compared by using Wilcoxon signed-rank test. The mean of VAS score of the microneedle treated side was 2.1 ± 1.1 while that of the untreated side was 5.9 ± 0.9 and this difference was statistically significant (Wilcoxon signed-rank test, the Z-value is - 5.9683 and the p-value is < 0.001). This study revealed that microneedle application, with a roller-type device, is a safe and easy procedure in providing sufficient anesthesia for facial laser resurfacing without the need for supplementary nerve blocks or injections.

Thermal Pretreatment For TRU Waste Sorting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasaki, T.; Aoyama, Y.; Miyamoto, Y.

2008-07-01

Japan Atomic Energy Agency conducted a study on thermal treatment of TRU waste to develop a removal technology for materials that are forbidden for disposal. The thermal pretreatment in which hot nitrogen and/or air is introduced to the waste is a process of removing combustibles, liquids, and low melting point metals from PVC wrapped TRU waste. In this study, thermal pretreatment of simulated waste was conducted using a desktop thermal treatment vessel and a laboratory scale thermal pretreatment system. Combustibles and low melting point metals are effectively separated from wastes by choosing appropriate temperature of flowing gases. Combustibles such asmore » papers, PVC, oil, etc. were removed and low melting point metals such as zinc, lead, and aluminum were separated from the simulated waste by the thermal pretreatment. (authors)« less

Operating Room Environment Control. Part A: a Valve Cannister System for Anesthetic Gas Adsorption. Part B: a State-of-the-art Survey of Laminar Flow Operating Rooms. Part C: Three Laminar Flow Experiments

NASA Technical Reports Server (NTRS)

Meyer, J. S.; Kosovich, J.

1973-01-01

An anesthetic gas flow pop-off valve canister is described that is airtight and permits the patient to breath freely. Once its release mechanism is activated, the exhaust gases are collected at a hose adapter and passed through activated coal for adsorption. A survey of laminar air flow clean rooms is presented and the installation of laminar cross flow air systems in operating rooms is recommended. Laminar flow ventilation experiments determine drying period evaporation rates for chicken intestines, sponges, and sections of pig stomach.

Development and testing of a wet oxidation waste processing system. [for waste treatment aboard manned spacecraft

NASA Technical Reports Server (NTRS)

Weitzmann, A. L.

1977-01-01

The wet oxidation process is considered as a potential treatment method for wastes aboard manned spacecraft for these reasons: (1) Fecal and urine wastes are processed to sterile water and CO2 gas. However, the water requires post-treatment to remove salts and odor; (2) the residual ash is negligible in quantity, sterile and easily collected; and (3) the product CO2 gas can be processed through a reduction step to aid in material balance if needed. Reaction of waste materials with oxygen at elevated temperature and pressure also produces some nitrous oxide, as well as trace amounts of a few other gases.

77 FR 16537 - Grant of Authority for Subzone Status Piramal Critical Care, Inc., (Inhalation Anesthetics...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... Status Piramal Critical Care, Inc., (Inhalation Anesthetics), Bethlehem, PA Pursuant to its authority... anesthetic manufacturing and distribution facilities of Piramal Critical Care, Inc., located in Bethlehem... inhalation anesthetics at the facilities of Piramal Critical Care, Inc., located in Bethlehem, Pennsylvania...

[Gases in vitreoretinal surgery].

PubMed

Janco, L; Vida, R; Bartos, M; Villémová, K; Izák, M

2012-02-01

To evaluate the importance and benefits of using gases in vitreoretinal surgery. The gases represent a wide group of substances used in eye surgery for more than 100 years. The role of intraocular gases in vitreoretinal surgery is irreplaceable. Their use is still considered to be the "gold standard". An important step in eye surgery was the introduction of expanding gases--sulfur hexafluoride and perfluorocarbons into routine clinical practice. The most common indications for the use of intraocular gases are: retinal detachment, idiopathic macular hole, complications of vitreoretinal surgery and others. The introduction of intraocular gases into routine clinical practice, along with other modern surgical techniques resulted in significant improvement of postoperative outcomes in a wide range of eye diseases. Understanding the principles of intraocular gases use brings the benefits to the patient and physician as well. Due to their physical and chemical properties they pose far the best and most appropriate variant of intraocular tamponade. Gases also bring some disadvantages, such as difficulties in detailed fundus examination, visual acuity testing, ultrasonographic examination, difficulties in application of intravitreal drugs or reduced possibility of retina laser treatment. The gases significantly change optical system properties of the eye. The use of gases in vitreoretinal surgery has significantly increased success rate of retinal detachment surgery, complicated posterior segment cases, trauma, surgery of the macula and other diseases.

Effects of an anesthetic mixture of medetomidine, midazolam, and butorphanol in rats-strain difference and antagonism by atipamezole.

PubMed

Kirihara, Yumiko; Takechi, Mayumi; Kurosaki, Kaoru; Kobayashi, Yuta; Saito, Yoji; Takeuchi, Takashi

2016-01-01

An anesthetic mixture of medetomidine (MED), midazolam (MID), and butorphanol (BUT) has been used in laboratory animals. We previously reported that this anesthetic mixture produced closely similar anesthetic effects in BALB/c and C57BL/6J strains. We also demonstrated the efficacy of atipamezole (ATI), an antagonist of MED that produced quick recovery from anesthesia in mice. Anesthetics have various anesthetic effects among animal strains. However, the differences in the effects of anesthetic mixtures in rats are unclear. In the present study, we first examined effects of the abovementioned anesthetic mixture using three different rat strains: Wistar (WST), Sprague-Dawley (SD), and Fischer 344 (F344). Second, we examined how different dosages and optimum injection timing of ATI affected recovery from anesthesia in rats. We used the anesthetic score to measure anesthetic duration and a pulse oximeter to monitor vital signs. We found no significant differences in anesthetic duration among the three different strains. However, recovery from anesthesia in the SD strain took significantly longer than in the other strains. The antagonistic effects of ATI (0.15 mg/kg and 0.75 mg/kg) were equivalent when administered at 30 min after anesthetic mixture administration. The antagonistic effects of ATI 0.75 mg/kg were stronger than those of ATI 0.15 mg/kg at 10 min after anesthetic mixture administration. This anesthetic mixture is a useful drug that can induce similar anesthetic effects in three different strains and has an antagonist, ATI, that makes rats quickly recover from anesthesia. These results may contribute to the welfare of laboratory animals.

Local anesthetic systemic toxicity: update on mechanisms and treatment.

PubMed

Wolfe, John W; Butterworth, John F

2011-10-01

With increases in use of regional anesthesia, local anesthetic systemic toxicity (LAST) has been a topic of interest and debate. Despite many years of research, the exact cause and best treatment of LAST (particularly local anesthetic cardiotoxicity) remain unclear. This review will summarize what is known and what remains uncertain about LAST and its treatment, including information published in the past 12-18 months. Several authorities, including the American Society of Regional Anesthesia and Pain Medicine, have published guidelines on prevention and treatment of LAST. Experimental data continue to add to better understanding of LAST and its treatment. The data are not entirely consistent, but themes include continued evidence to support the ideas that LAST cardiotoxicity occurs primarily at sodium channels, lipid emulsion is a reasonably well tolerated and effective treatment, and there may be qualitative differences in cardiotoxicity caused by low and high-potency local anesthetics. Regarding mechanism(s) of LAST, the evidence remains mixed, but it is likely that local anesthetic cardiotoxicity primarily arises from a blockade of sodium channels. As for treatment, in addition to ventilation, oxygenation, and chest compressions, lipid emulsion therapy should be a primary element in the treatment of cardiovascular LAST. The use of epinephrine and vasopressin should be tailored to specifics of an episode of LAST, and doses should be kept as low as possible while still achieving the desired effects.

Method for storing radioactive combustible waste

DOEpatents

Godbee, H.W.; Lovelace, R.C.

1973-10-01

A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

Sources and potential application of waste heat utilization at a gas processing facility

NASA Astrophysics Data System (ADS)

Alshehhi, Alyas Ali

Waste heat recovery (WHR) has the potential to significantly improve the efficiency of oil and gas plants, chemical and other processing facilities, and reduce their environmental impact. In this Thesis a comprehensive energy audit at Abu Dhabi Gas Industries Ltd. (GASCO) ASAB gas processing facilities is undertaken to identify sources of waste heat and evaluate their potential for on-site recovery. Two plants are considered, namely ASAB0 and ASAB1. Waste heat evaluation criteria include waste heat grade (i.e., temperature), rate, accessibility (i.e., proximity) to potential on-site waste heat recovery applications, and potential impact of recovery on installation performance and safety. The operating parameters of key waste heat source producing equipment are compiled, as well as characteristics of the waste heat streams. In addition, potential waste heat recovery applications and strategies are proposed, focusing on utilities, i.e., enhancement of process cooling/heating, electrical/mechanical power generation, and steam production. The sources of waste heat identified at ASAB facilities consist of gas turbine and gas generator exhaust gases, flared gases, excess propane cooling capacity, excess process steam, process gas air-cooler heat dissipation, furnace exhaust gases and steam turbine outlet steam. Of the above waste heat sources, exhaust gases from five gas turbines and one gas generator at ASAB0 plant, as well as from four gas turbines at ASAB1 plant, were found to meet the rate (i.e., > 1 MW), grade (i.e., > 180°C), accessibility (i.e., < 50 m from potential on-site WHR applications) and minimal impact criteria on the performance and safety of existing installations, for potential waste heat recovery. The total amount of waste heat meeting these criteria were estimated at 256 MW and 289 MW at ASAB0 and ASAB1 plants, respectively, both of which are substantial. Of the 289 MW waste generated at ASAB1, approximately 173 MW are recovered by waste heat

Anesthetic Neuroprotection in Experimental Stroke in Rodents: A Systematic Review and Meta-analysis.

PubMed

Archer, David P; Walker, Andrew M; McCann, Sarah K; Moser, Joanna J; Appireddy, Ramana M

2017-04-01

Patients undergoing endovascular therapy for acute ischemic stroke may require general anesthesia to undergo the procedure. At present, there is little clinical evidence to guide the choice of anesthetic in this acute setting. The clinical implications of experimental studies demonstrating anesthetic neuroprotection are poorly understood. Here, the authors evaluated the impact of anesthetic treatment on neurologic outcome in experimental stroke. Controlled studies of anesthetics in stroke using the filament occlusion model were identified in electronic databases up to December 15, 2015. The primary outcome measures, infarct volume, and neurologic deficit score were used to calculate the normalized mean difference for each comparison. Meta-analysis of normalized mean difference values provided estimates of neuroprotection and contributions of predefined factors: study quality, the timing of treatment, and the duration of ischemia. In 80 retrieved publications anesthetic treatment reduced neurologic injury by 28% (95% CI, 24 to 32%; P < 0.0001). Internal validity was high: publication bias enhanced the effect size by 4% or less, effect size increased with study quality (P = 0.0004), and approximately 70% of studies were adequately powered. Apart from study quality, no predefined factor influenced neuroprotection. Neuroprotection failed in animals with comorbidities. Neuroprotection by anesthetics was associated with prosurvival mechanisms. Anesthetic neuroprotection is a robust finding in studies using the filament occlusion model of ischemic stroke and should be assumed to influence outcomes in studies using this model. Neuroprotection failed in female animals and animals with comorbidities, suggesting that the results in young male animals may not reflect human stroke.

Comparison of Different Muscle-Relaxant Anesthetics on Growth, Migration and Invasion of Gastric Cancer Cells.

PubMed

Jiang, Aihua; Zhao, Huishan; Liu, Xiaofei; Yu, Mingwei; Chen, Jian; Jiang, Wen G

2017-08-01

Muscle relaxants, also known as neuromuscular blocking agents, can block nerve impulses to the muscles and are always used in surgery for general anesthesia. However, the effect of muscle-relaxant anesthetics on cell activity in gastric cancer is currently unknown. The present study aimed to examine and compare the role of three different muscle-relaxant anesthetics in gastric cancer cells. Gastric cancer cells (SGC7901 and BGC 823) were treated with a different dose of muscle-relaxant anesthetics, Rocuronium bromide (Rb), Vecuronium bromide (Vb) and Cisatracurium Besilate (CB). Using in vitro models, the effects on gastric cancer cell invasion, growth and migration of various anesthetics were subsequently investigated. We found that Rb increased the growth, invasion and migration of gastric cancer cells SGC7901 and BGC823. However, Vb and CB, as relatively mitigative anesthetics, did not significantly affect gastric cancer cell malignant phenotype at their regular blood concentration. Our results are important in selecting the type and dose of anesthetic used for surgery of gastric cancer patients. An understanding of the effect of muscle-relaxant anesthetics and their impact on tumor metastasis is critical, since it provides insight into the appropriate anesthetic strategy that could improve long-term survival in some patients with gastric cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Densities of dextrose-free intrathecal local anesthetics, opioids, and combinations measured at 37 degrees C.

PubMed

Richardson, M G; Wissler, R N

1997-01-01

Dextrose-free anesthetic medications are commonly used to provide subarachnoid anesthesia and analgesia. Hypobaricity has been proposed as a mechanism to explain postural effects on the extent of sensory block produced by these drugs. Densities of dextrose-free solutions of local anesthetics and opioids, and commonly used anesthetic/opioid mixtures were determined at 37.00 degrees C for comparison with the density of human cerebrospinal fluid (CSF). Measurements accurate to 0.00001 g/mL were performed using a mechanical oscillation resonance frequency density meter. All undiluted solutions tested are hypobaric relative to human lumbar CSF with the exception of lidocaine 1.5% and 2.0% with epinephrine 1:200,000. All mixtures of local anesthetics and opioids tested are hypobaric. We observed good agreement between measured densities and calculated weighted average densities of anesthetic mixtures. While the influence of baricity on the clinical effects of dextrose-free intrathecal anesthetics remains controversial, attempts to attribute postural effects to the baricity of these drugs requires establishment of accurate density values. These density data may facilitate elucidation of the mechanisms underlying the behavior of dextrose-free intrathecal anesthetics.

Intraoperative Seizures: Anesthetic and Antiepileptic Drugs.

PubMed

Uribe, Alberto; Zuleta-Alarcon, Alix; Kassem, Mahmoud; Sandhu, Gurneet S; Bergese, Sergio D

2017-01-01

Epilepsy is a common condition with up to 1% prevalence in the general population. In the perioperative course of neurologic surgery patients, the use of prophylactic and therapeutic antiepileptic drugs is a common practice. Nonetheless, there is limited evidence supporting the use of prophylactic antiepileptics to prevent perioperative seizures and there are no guidelines for which anesthetic technique is preferred. To discuss the seizurogenic potential of anesthetic drugs and to discuss intraoperative seizures in neurosurgical patients. We performed a search of the literature available in PubMed and Ovid MEDLINE. We also included articles identified in the review of the references of these articles. The incidence of seizures is heterogenic among neurosurgical patients. Seizure prophylaxis is widely administered despite limited available evidence of its effectiveness. In epileptic patients, the recommendation is to continue antiepileptic drugs in the perioperative setting. In these patients, anesthesiologists may also limit the use of medications that alter the seizure threshold and avoid medications that pose significant pharmacological interaction with antiepileptic drugs. In conclusion, a knowledgeable multidisciplinary perioperative team is essential to avoid, identify and treat intraoperative seizures competently. In patients with a history of epilepsy it is recommended to continue antiepileptic therapy. Therefore, clinical judgment should guide the decision of administering seizure prophylaxis in neurosurgery patients according to an individual assessment of potential risk for seizures. Furthermore, there is a need for randomized controlled trials that support new protocols and/or guidelines for anesthetic and perioperative regimens to prevent and treat intraoperative seizures. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A proposal for a test method for assessment of hazard property HP 12 ("Release of an acute toxic gas") in hazardous waste classification - Experience from 49 waste.

PubMed

Hennebert, Pierre; Samaali, Ismahen; Molina, Pauline

2016-12-01

A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as "Release of an acute toxic gas": waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, 2014b). When the substances with the cited hazard statement codes react with water or an acid, they can release HCl, Cl 2 , HF, HCN, PH 3 , H 2 S, SO 2 (and two other gases very unlikely to be emitted, hydrazoic acid HN 3 and selenium oxide SeO 2 - a solid with low vapor pressure). Hence, a method is proposed:For a set of 49 waste, water addition did not produce gas. Nearly all the solid waste produced a gas in contact with hydrochloric acid in 5 min in an automated calcimeter with a volume >0.1L of gas per kg of waste. Since a plateau of pressure is reached only for half of the samples in 5 min, 6 h trial with calorimetric bombs or glass flasks were done and confirmed the results. Identification of the gases by portable probes showed that most of the tested samples emit mainly CO 2 . Toxic gases are emitted by four waste: metallic dust from the aluminum industry (CO), two air pollution control residue of industrial waste incinerator (H 2 S) and a halogenated solvent (organic volatile(s) compound(s)). HF has not been measured in these trials started before the present definition of HP 12. According to the definition of HP 12, only the H 2 S emission of substances with hazard statement EUH031 is accounted for. In view of the calcium content of the two air pollution control residue, the presence of calcium sulphide (EUH031) can be assumed. These two waste are therefore classified potentially hazardous for HP 12, from a total of 49 waste. They are also classified as hazardous for other properties (HP 7

Local anesthetic lidocaine delivery system: chitosan and hyaluronic acid-modified layer-by-layer lipid nanoparticles.

PubMed

Zhang, Laizhu; Wang, Jianguo; Chi, Huimin; Wang, Shilei

2016-11-01

Transdermal local anesthesia is one of the most applied strategies to avoid systemic adverse effects; there is an appealing need for a prolonged local anesthetic that would provide better bioavailability and longer pain relief with a single administration. Layer-by-layer (LBL) technique was used in this study to explore a nanosized drug delivery system for local anesthetic therapy. LBL-coated lidocaine-loaded nanostructured lipid nanoparticles (LBL-LA/NLCs) were prepared and characterized in terms of particle size (PS), zeta potential, drug encapsulation efficiency (EE), in vitro skin permeation and in vivo local anesthetic studies. Evaluation of the in vitro skin permeation and in vivo anesthesia effect illustrated that LBL-LA/NLCs can enhance and prolong the anesthetic effect of LA. LBL-LA/NLCs could function as a promising drug delivery strategy for overcoming the barrier function of the skin and could deliver anesthetic through the skin with sustained release behavior for local anesthetic therapy.

EFFECT OF RADIATION ON RESPONSE TO ANESTHETIC AGENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zauder, H.L.; Orkin, L.R.

1963-07-01

An attempt was made to determine if prior irradiation modified the response to anesthesia or if any anesthetic or anesthetics are associated with an abnormally high or low mortality, following irradiation. Swiss mice were irradiated by a conventional radiotherapy machine utilizing 250-kv x rays with 1- mm aluiminum and 0.5 mm copper filtration. The half-value layer was 1.5 mm of copper, and with a target-skin distance of 70 cm; the dose rate in air was 52 r/ min. A dose-response curve, relating mortality at 30 days to the amount of radiation delivered gave an LD/sub 5/ of 350 r, LD/submore » 25/ of 450 r, and LD/sub 95/ of 750 r. A chamber for the anesthetization of small animals with a known, reproducible concentration of anesthetic agent was designed providing for constant circulation of the gas mixtures, explosive or nonexplosive. Utilizing this apparatus, groups of mice were andesthetized with 6% divinyl ether, 6% diethyl ether, 1.5% halothane, 1.8% trichlorethylene, and 18% cyclopropane. With the latter, oxygen was added to the chamber in sufficient quandtity to provide a concentration of 20 to 25%. Pentobarbital (Nembutal) 30 mg/kg, thiopental sodium (Pentothal) 70 mg/kg, or meperidine hydrochloride (Demerol) 25 mg/kg was injected intraperitoneally into mice with and without prior x radiation. There was no mortality associated with these dosages in the control animals. All drugs were administered to the irradiated animals on the 1st to 28th day postirradiation. In mice irradiated with an LD/sub 5/ (350 r) and anesthetized subsequently with divinyl ether, diethyl ether, or halothane, an increase in the mortality over control values was observed. This increase was greatest following divinyl ether; its administration 7 or more days following irradiation resulted in the death of 10 to 30% of the animals during the 45-min period of anesthetization. After 350 r, meperidine and pentobarbital did not increase montality, but thiopental increased markedly the number

Method and apparatus for treating gaseous effluents from waste treatment systems

DOEpatents

Flannery, Philip A.; Kujawa, Stephan T.

2000-01-01

Effluents from a waste treatment operation are incinerated and oxidized by passing the gases through an inductively coupled plasmas arc torch. The effluents are transformed into plasma within the torch. At extremely high plasma temperatures, the effluents quickly oxidize. The process results in high temperature oxidation of the gases without addition of any mass flow for introduction of energy.

Methylparaben concentration in commercial Brazilian local anesthetics solutions

PubMed Central

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

Evaluation of anesthetic technique on surgical site infections (SSIs) at a single institution.

PubMed

Curry, Craig S; Smith, Kahsi A; Allyn, John W

2014-12-01

To determine whether the previously published relationship between anesthetic technique and rate of surgical site infections (SSIs) was influenced by institution specific effects. Retrospective Review of Quality Assurance and Hospital Epidemiology databases. Metropolitan medical center. The records of 7,751 patients who underwent knee or hip joint replacement from 2004 to 2010 were analyzed. Data regarding anesthetic technique, age, ASA status, gender, postoperative temperature, duration of anesthesia and type of surgery were from the department of anesthesiology quality assurance database and SSI cases were identified from the department of epidemiology database. The impact of anesthetic technique and other variables was assessed using bivariate and multivariate techniques. There was no association of anesthetic technique on the rate of SSI. Duration of anesthesia and ASA status were associated with effects on the rate of SSI. The impact of anesthetic technique on SSI following hip and knee replacement surgery may be site specific and using locally gathered quality data may assist in assessing specific institutional impact. Copyright © 2014 Elsevier Inc. All rights reserved.

Research on fission fragment excitation of gases and nuclear pumping of lasers

NASA Technical Reports Server (NTRS)

Schneider, R. T.; Davie, R. N.; Davis, J. F.; Fuller, J. L.; Paternoster, R. R.; Shipman, G. R.; Sterritt, D. E.; Helmick, H. H.

1974-01-01

Experimental investigations of fission fragment excited gases are reported along with a theoretical analysis of population inversions in fission fragment excited helium. Other studies reported include: nuclear augmentation of gas lasers, direct nuclear pumping of a helium-xenon laser, measurements of a repetitively pulsed high-power CO2 laser, thermodynamic properties of UF6 and UF6/He mixtures, and nuclear waste disposal utilizing a gaseous core reactor.

Lipid emulsions enhance the norepinephrine-mediated reversal of local anesthetic-induced vasodilation at toxic doses.

PubMed

Lee, Soo Hee; Sung, Hui-Jin; Ok, Seong-Ho; Yu, Jongsun; Choi, Mun-Jeoung; Lim, Jin Soo; Sohn, Ju-Tae

2013-11-01

Intravenous lipid emulsions have been used to treat the systemic toxicity of local anesthetics. The goal of this in vitro study was to examine the effects of lipid emulsions on the norepinephrine-mediated reversal of vasodilation induced by high doses of levobupivacaine, ropivacaine, and mepivacaine in isolated endothelium-denuded rat aorta, and to determine whether such effects are associated with the lipid solubility of local anesthetics. The effects of lipid emulsions (0.30, 0.49, 1.40, and 2.61%) on norepinephrine concentration-responses in high-dose local anesthetic (6×10(-4) M levobupivacaine, 2×10(-3) M ropivacaine, and 7×10(-3) M mepivacaine)-induced vasodilation of isolated aorta precontracted with 60 mM KCl were assessed. The effects of lipid emulsions on local anesthetic- and diltiazem-induced vasodilation in isolated aorta precontracted with phenylephrine were also assessed. Lipid emulsions (0.30%) enhanced norepinephrine-induced contraction in levobupivacaine-induced vasodilation, whereas 1.40 and 2.61% lipid emulsions enhanced norepinephrine-induced contraction in both ropivacaine- and mepivacaine-induced vasodilation, respectively. Lipid emulsions (0.20, 0.49 and 1.40%) inhibited vasodilation induced by levobupivacaine and ropivacaine, whereas 1.40 and 2.61% lipid emulsions slightly attenuated mepivacaine (3×10(-3) M)-induced vasodilation. In addition, lipid emulsions attenuated diltiazem-induced vasodilation. Lipid emulsions enhanced norepinephrine-induced contraction in endothelium-denuded aorta without pretreatment with local anesthetics. Taken together, these results suggest that lipid emulsions enhance the norepinephrine-mediated reversal of local anesthetic-induced vasodilation at toxic anesthetic doses and inhibit local anesthetic-induced vasodilation in a manner correlated with the lipid solubility of a particular local anesthetic.

Composting of food wastes: Status and challenges.

PubMed

Cerda, Alejandra; Artola, Adriana; Font, Xavier; Barrena, Raquel; Gea, Teresa; Sánchez, Antoni

2018-01-01

This review analyses the main challenges of the process of food waste composting and examines the crucial aspects related to the quality of the produced compost. Although recent advances have been made in crucial aspects of the process, such composting microbiology, improvements are needed in process monitoring. Therefore, specific problems related to food waste composting, such as the presence of impurities, are thoroughly analysed in this study. In addition, environmental impacts related to food waste composting, such as emissions of greenhouse gases and odours, are discussed. Finally, the use of food waste compost in soil bioremediation is discussed in detail. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method for waste collection and storage

NASA Technical Reports Server (NTRS)

Thornton, William E., Jr. (Inventor); Whitmore, Henry B. (Inventor)

1990-01-01

A method for collection of fecal matter designed to operate efficiently in a zero gravity environment was invented. The system consists of a waste collection area within a body having a seat opening. Low pressure within the waste collection area directs fecal matter away from the user's buttocks and prevents the escape of waste gases. The user actuates a piston covered with an absorbent pad that sweeps through the waste collection area to collect fecal matter, scrub the waste collector area, press the waste against an end of the waste collection area and retracts, leaving the used pad. Multiple pads are provided on the piston to accommodate multiple usages. Also a valve allows air to be drawn through the body, which keeps the valve from becomming plugged with the feces. A sheet feeder feeds fresh sheets of absorbent pads to a face of the piston with each actuation.

Anesthetics lower Tc of a 2D miscibility critical point in the plasma membrane

NASA Astrophysics Data System (ADS)

Machta, Benjamin; Gray, Elly; Veatch, Sarah

2014-03-01

Many small hydrophobic molecules induce general anesthesia. Their efficacy as anesthetics has been shown to correlate both with their hydrophobicity and with their potency in inhibiting certain ligand gated ion channels. I will first report on our experiments on the effects that these molecules have on the two-dimensional miscibility critical point observed in cell derived vesicles (GPMVs). We show that anesthetics depress the critical temperature (Tc) of these GPMVs but do not strongly affect the ratio of phases found below Tc. The magnitude of this affect is consistent across the n-alcohols only when their concentration is rescaled by the median anesthetic concentration (AC50) for tadpole anesthesia and at AC50 we see a 4K downward shift in Tc. I will next present a model in which anesthetics interfere with native allosteric regulation of ligand gated channels by the critical membrane, showing that our observed change in critical properties could lead to the previously observed changes in channel conductance without a direct interaction between anesthetic molecules and their target proteins. Finally, I will discuss ongoing experiments that will clarify the role of this membrane effect in mediating the organism level anesthetic response.

Anesthetic cardioprotection in clinical practice from proof-of-concept to clinical applications.

PubMed

Zaugg, Michael; Lucchinetti, Eliana; Behmanesh, Saeid; Clanachan, Alexander S

2014-01-01

In 2007, the American Heart Association (AHA) recommended (class IIa, level of evidence B) in their guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery volatile anesthetics as first choice for general anesthesia in hemodynamically stable patients at risk for myocardial ischemia. This recommendation was based on results from patients undergoing coronary artery bypass grafting (CABG) surgery and thus subject to criticism. However, since a "good anesthetic" often resembles a piece of art in the complex perioperative environment, and is difficult to highly standardize, it seems unlikely that large-scale randomized control trials in noncardiac surgical patients will be performed in the near future to tackle this question. There is growing evidence that ether-derived volatile anesthetics and opioids provide cardioprotection in patients undergoing CABG surgery. Since 2011, the American College of Cardiology Foundation/AHA have recommended a "volatile-based anesthesia" for these procedures (class IIa, level of evidence A). It is very likely that volatile anesthetics and opioids also protect hearts of noncardiac surgical patients. However, age, diabetes and myocardial remodeling diminish the cardioprotective benefits of anesthetics. In patients at risk for perioperative cardiovascular complications, it is essential to abandon the use of "anti-conditioning" drugs (sulfonylureas and COX-2 inhibitors) and probably glitazones. There is significant interference in cardioprotection between sevoflurane and propofol, which should not be used concomitantly during anesthesia if possible. Any type of ischemic "conditioning" appears to exhibit markedly reduced protection or completely loses protection in the presence of volatile anesthetics and/or opioids.

Production of chemicals from C1 gases (CO, CO2) by Clostridium carboxidivorans.

PubMed

Fernández-Naveira, Ánxela; Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

2017-03-01

Bioprocesses in conventional second generation biorefineries are mainly based on the fermentation of sugars obtained from lignocellulosic biomass or agro-industrial wastes. An alternative to this process consists in gasifying those same feedstocks or even other carbon-containing materials to obtain syngas which can also be fermented by some anaerobic bacteria to produce chemicals or fuels. Carbon monoxide, carbon dioxide and hydrogen, which are the main components of syngas, are also found in some industrial waste gases, among others in steel industries. Clostridium carboxidivorans is able to metabolise such gases to produce ethanol and higher alcohols, i.e. butanol and hexanol, following the Wood-Ljungdahl pathway. This does simultaneously allow the removal of volatile pollutants involved in climate change. The bioconversion is a two step process in which organic acids (acetate, butyrate, hexanoate) are produced first, followed by the accumulation of alcohols; although partial overlap in time of acids and alcohols production may sometimes take place as well. Several parameters, among others pH, temperature, or gas-feed flow rates in bioreactors, affect the bioconversion process. Besides, the accumulation of high concentrations of alcohols in the fermentation broth inhibits the growth and metabolic activity of C. carboxidivorans.

Zika virus: review and obstetric anesthetic clinical considerations.

PubMed

Padilla, Cesar; Pan, Aileen; Geller, Andrew; Zakowski, Mark I

2016-12-01

To review the clinical and basic science literature regarding Zika viral illness and highlight relevant findings for obstetric anesthesiologists. This review provides a global review of Zika viral illness, transmission patterns, pathophysiology of disease, and anesthetic management of the parturient with Zika viral illness and associated comorbidities. Systematic review. Large academic hospital. None. None. None. None. With the rapid spread of Zika virus and expected increase of spread in the summer of 2016, this review provides anesthesiologists with current recommendations, physiologic alterations, and anesthetic considerations in regard to the parturient with Zika viral illness and associated diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Hypnotic hypersensitivity to volatile anesthetics and dexmedetomidine in dopamine β-hydroxylase knockout mice.

PubMed

Hu, Frances Y; Hanna, George M; Han, Wei; Mardini, Feras; Thomas, Steven A; Wyner, Abraham J; Kelz, Max B

2012-11-01

Multiple lines of evidence suggest that the adrenergic system can modulate sensitivity to anesthetic-induced immobility and anesthetic-induced hypnosis as well. However, several considerations prevent the conclusion that the endogenous adrenergic ligands norepinephrine and epinephrine alter anesthetic sensitivity. Using dopamine β-hydroxylase knockout (Dbh) mice genetically engineered to lack the adrenergic ligands and their siblings with normal adrenergic levels, we test the contribution of the adrenergic ligands upon volatile anesthetic induction and emergence. Moreover, we investigate the effects of intravenous dexmedetomidine in adrenergic-deficient mice and their siblings using both righting reflex and processed electroencephalographic measures of anesthetic hypnosis. We demonstrate that the loss of norepinephrine and epinephrine and not other neuromodulators co-packaged in adrenergic neurons is sufficient to cause hypersensitivity to induction of volatile anesthesia. However, the most profound effect of adrenergic deficiency is retarding emergence from anesthesia, which takes two to three times as long in Dbh mice for sevoflurane, isoflurane, and halothane. Having shown that Dbh mice are hypersensitive to volatile anesthetics, we further demonstrate that their hypnotic hypersensitivity persists at multiple doses of dexmedetomidine. Dbh mice exhibit up to 67% shorter latencies to loss of righting reflex and up to 545% longer durations of dexmedetomidine-induced general anesthesia. Central rescue of adrenergic signaling restores control-like dexmedetomidine sensitivity. A novel continuous electroencephalographic analysis illustrates that the longer duration of dexmedetomidine-induced hypnosis is not due to a motor confound, but occurs because of impaired anesthetic emergence. Adrenergic signaling is essential for normal emergence from general anesthesia. Dexmedetomidine-induced general anesthesia does not depend on inhibition of adrenergic neurotransmission.

Hypnotic Hypersensitivity to Volatile Anesthetics and Dexmedetomidine in Dopamine β-Hydroxylase Knockout Mice

PubMed Central

Hu, Frances Y.; Hanna, George M.; Han, Wei; Mardini, Feras; Thomas, Steven A.; Wyner, Abraham J.; Kelz, Max B.

2012-01-01

BACKGROUND Multiple lines of evidence suggest that the adrenergic system can modulate sensitivity to anesthetic-induced immobility and anesthetic-induced hypnosis as well. However, several considerations prevent the conclusion that the endogenous adrenergic ligands norepinephrine and epinephrine alter anesthetic sensitivity. METHODS Using dopamine β-hydroxylase (Dbh−/−) mice genetically engineered to lack the adrenergic ligands and their siblings with normal adrenergic levels, we test the contribution of the adrenergic ligands upon volatile anesthetic induction and emergence. Moreover, we investigate the effects of intravenous dexmedetomidine in adrenergic-deficient mice and their siblings using both righting reflex and processed electroencephalographic measures of anesthetic hypnosis. RESULTS We demonstrate that the loss of norepinephrine and epinephrine and not other neuromodulators copackaged in adrenergic neurons is sufficient to cause hypersensitivity to induction of volatile anesthesia. However, the most profound effect of adrenergic deficiency is retarding emergence from anesthesia, which takes two to three times as long in Dbh−/− mice for sevoflurane, isoflurane, and halothane. Having shown that Dbh−/− mice are hypersensitive to volatile anesthetics, we further demonstrate that their hypnotic hypersensitivity persists at multiple doses of dexmedetomidine. Dbh−/− mice exhibit up to 67% shorter latencies to loss of righting reflex and up to 545% longer durations of dexmedetomidine-induced general anesthesia. Central rescue of adrenergic signaling restores control-like dexmedetomidine sensitivity. A novel continuous electroencephalographic analysis illustrates that the longer duration of dexmedetomidine-induced hypnosis is not due to a motor confound, but occurs because of impaired anesthetic emergence. CONCLUSIONS Adrenergic signaling is essential for normal emergence from general anesthesia. Dexmedetomidine-induced general anesthesia does

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

PubMed

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.

Anesthesia and Duchenne or Becker muscular dystrophy: review of 117 anesthetic exposures.

PubMed

Segura, Leal G; Lorenz, Jessica D; Weingarten, Toby N; Scavonetto, Federica; Bojanić, Katarina; Selcen, Duygu; Sprung, Juraj

2013-09-01

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are associated with life-threatening perioperative complications, including rhabdomyolysis, hyperkalemia, and hyperthermia. Current recommendations contraindicate use of succinylcholine and volatile anesthetics; however, the latter recommendation remains controversial. To review the perioperative outcomes of patients with DMD and BMD. We reviewed records of patients with DMD or BMD who underwent anesthetic management at our institution from January 1990 through December 2011. We identified 47 patients (DMD, 37; BMD, 10) who underwent 117 anesthetic exposures (DMD, 101; BMD, 16). Volatile anesthetic agents were used 66 times (DMD, 59; BMD, 7). One patient with undiagnosed BMD received succinylcholine and developed acute rhabdomyolysis and hyperkalemic cardiac arrest. All other major complications were attributed to the procedure (i.e., large bleeding), to preexisting comorbidities (i.e., respiratory failure, cardiac disease), or to both. Use of succinylcholine in children with dystrophinopathy is contraindicated. These patients have significant comorbidities and are frequently undergoing extensive operations; complications related to these factors can develop, as evidenced by our series. These complications may occur with use of volatile and nonvolatile anesthetics. However, because most of our patients were older than 8 years at the time of surgery, our observation cannot be generalized to younger dystrophin-deficient children. © 2013 John Wiley & Sons Ltd.

EFFECTIVENESS OF THE ANESTHETIC AQUI-S® 20E IN MARINE FINFISH AND ELASMOBRANCHS.

PubMed

Silbernagel, Constance; Yochem, Pamela

2016-04-01

Immersion anesthetics are used in hatchery settings by veterinarians, field biologists, and laboratory researchers to aid in handling finfish for medical procedures, research purposes, and moderating perceived stress responses. The only Food and Drug Administration- (FDA) approved anesthetic for food fish, tricaine methanesulfonate, requires a 21-d withdrawal period prior to harvest. Ten percent eugenol (AQUI-S® 20E) has been gaining momentum for FDA approval because of its 0-d withdrawal time if fish are not of harvestable size within 72 h of exposure. We performed two trials to determine appropriate anesthetic doses for two cultured marine finfish: Atractoscion nobilis (white seabass, WSB) and Seriola lalandi (California yellowtail, YT). Fish were held in a treated water bath for 10 min or until opercular beat rate slowed to a rate of <2 beats/min. Based on these results, we conducted a field trial with wild Paralabrax maculatofasciatus (spotted bay bass), Paralabrax nebulifer (barred sand bass), Paralichthys californicus (California halibut), Triakis semifasciata (leopard shark), and Mustelus californicus (grey smooth-hound) at a single dosing regime, with animals held 5-10 min in anesthetic baths. Anesthetic dosing of 35-55 mg L(-1) provided relatively fast induction and good anesthetic maintenance in cultured and wild finfish. Anesthetic induction times were comparable among S. lalandi and A. nobilis at 35-mg L(-1) to 75-mg L(-1) doses, but recovery times were variable. Mortality rates of 20-90% were observed at higher doses (75 mg L(-1) and 100 mg L(-1), A. nobilis; 55 mg L(-1) and 75 mg L(-1), S. lalandi). The apparent increase in sensitivity of S. lalandi may have been associated with nutritional stress in the fish tested. There were no differences in time to anesthesia or recovery among wild finfish species tested at a single dose. Anesthetic induction, maintenance, and recovery were less predictable in the elasmobranch species tested and additional

A Conserved Behavioral State Barrier Impedes Transitions between Anesthetic-Induced Unconsciousness and Wakefulness: Evidence for Neural Inertia

PubMed Central

Friedman, Eliot B.; Sun, Yi; Moore, Jason T.; Hung, Hsiao-Tung; Meng, Qing Cheng; Perera, Priyan; Joiner, William J.; Thomas, Steven A.; Eckenhoff, Roderic G.; Sehgal, Amita; Kelz, Max B.

2010-01-01

One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia is commonly attributed to drug-induced global modulation of neuronal function, while emergence from anesthesia has been thought to occur passively, paralleling elimination of the anesthetic from its sites in the central nervous system (CNS). If this were true, then CNS anesthetic concentrations on induction and emergence would be indistinguishable. By generating anesthetic dose-response data in both insects and mammals, we demonstrate that the forward and reverse paths through which anesthetic-induced unconsciousness arises and dissipates are not identical. Instead they exhibit hysteresis that is not fully explained by pharmacokinetics as previously thought. Single gene mutations that affect sleep-wake states are shown to collapse or widen anesthetic hysteresis without obvious confounding effects on volatile anesthetic uptake, distribution, or metabolism. We propose a fundamental and biologically conserved concept of neural inertia, a tendency of the CNS to resist behavioral state transitions between conscious and unconscious states. We demonstrate that such a barrier separates wakeful and anesthetized states for multiple anesthetics in both flies and mice, and argue that it contributes to the hysteresis observed when the brain transitions between conscious and unconscious states. PMID:20689589

40 CFR 63.1094 - What waste streams are exempt from the requirements of this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange... section are exempt from this subpart. (a) Waste in the form of gases or vapors that is emitted from process fluids. (b) Waste that is contained in a segregated storm water sewer system. Waste Requirements ...

Safety and Efficacy of Various Combinations of Injectable Anesthetics in BALB/c Mice

PubMed Central

Buitrago, Sandra; Martin, Thomas E; Tetens-Woodring, Joanne; Belicha-Villanueva, Alan; Wilding, Gregory E

2008-01-01

Four combinations of drugs—ketamine–xylazine, ketamine–xylazine–acepromazine (KXA), ketamine–xylazine–buprenorphine, and ketamine–xylazine–carprofen—were compared for their ability to produce anesthesia in BALB/c mice. Induction time, anesthetic duration, blood pressure, pulse rate, and time to recovery were recorded. The anesthesia induced by each anesthetic combination was assessed by using reflex responses to standardized stimuli. The KXA combination produced stable physiologic parameters and was associated with the longest duration of anesthesia (40 ± 8 min); immobility was produced in all other groups (38 ± 5 min), but a surgical plane of anesthesia could not be confirmed. All anesthetic protocols produced significant hypotension. No deaths occurred. We recommend KXA as a safe and reliable anesthetic for mice requiring a surgical plane of anesthesia. PMID:18210992

Emission of greenhouse gases from waste incineration in Korea.

PubMed

Hwang, Kum-Lok; Choi, Sang-Min; Kim, Moon-Kyung; Heo, Jong-Bae; Zoh, Kyung-Duk

2017-07-01

Greenhouse gas (GHG) emission factors previously reported from various waste incineration plants have shown significant variations according to country-specific, plant-specific, and operational conditions. The purpose of this study is to estimate GHG emissions and emission factors at nine incineration facilities in Korea by measuring the GHG concentrations in the flue gas samples. The selected incineration plants had different operation systems (i.e., stoker, fluidized bed, moving grate, rotary kiln, and kiln & stoker), and different nitrogen oxide (NO x ) removal systems (i.e., selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR)) to treat municipal solid waste (MSW), commercial solid waste (CSW), and specified waste (SW). The total mean emission factors for A and B facilities for MSW incineration were found to be 134 ± 17 kg CO 2 ton -1 , 88 ± 36 g CH 4 ton -1 , and 69 ± 16 g N 2 O ton -1 , while those for CSW incineration were 22.56 g CH 4 ton -1 and 259.76 g N 2 O ton -1 , and for SW incineration emission factors were 2959 kg CO 2 ton -1 , 43.44 g CH 4 ton -1 and 401.21 g N 2 O ton -1 , respectively. Total emissions calculated using annual incineration for MSW were 3587 ton CO 2 -eq yr -1 for A facility and 11,082 ton CO 2 -eq yr -1 for B facility, while those of IPCC default values were 13,167 ton CO 2- eq yr -1 for A facility and 32,916 ton CO 2- eq yr -1 , indicating that the emissions of IPCC default values were estimated higher than those of the plant-specific emission factors. The emission of CSW for C facility was 1403 ton CO 2 -eq yr -1 , while those of SW for D to I facilities was 28,830 ton CO 2 -eq yr -1 . The sensitivity analysis using a Monte Carlo simulation for GHG emission factors in MSW showed that the GHG concentrations have a greater impact than the incineration amount and flow rate of flue gas. For MSW incineration plants using the same stoker type in operation, the estimated emissions and

Multivariable analysis of anesthetic factors associated with time to extubation in dogs.

PubMed

Kleine, Stephanie; Hofmeister, Erik; Egan, Katrina

2014-12-01

The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P < 0.025) was associated with a shorter time to extubation, while premedication with acepromazine (P = 0.000) was associated with a longer time to extubation. Time to extubation was increased by 0.311 minutes for every kilogram increase in body weight (P = 0.000), 5.924 minutes for every 1 °C loss in body temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia. Published by Elsevier Ltd.

Local anesthetics differentially inhibit sympathetic neuron-mediated and C fiber-mediated synovial neurogenic plasma extravasation.

PubMed

Pietruck, Christian; Grond, Stefan; Xie, Guo-Xi; Palmer, Pamela P

2003-05-01

Local anesthetics are used for local irrigation after many types of operations. However, recent evidence of toxic effects of local anesthetics at large concentrations during continuous administration suggests an advantage of using decreased local anesthetic concentrations for irrigation solutions. In this study, we determined whether smaller concentrations of local anesthetics may maintain an antiinflammatory and, therefore, analgesic effect without the risk of possible toxicity. Lidocaine and bupivacaine were studied for their ability to inhibit both components of neurogenic inflammation-C fiber-mediated and sympathetic postganglionic neuron (SPGN)-mediated inflammation-in the rat knee joint. Intraarticular lidocaine 0.02% reduced 5-hydroxytryptamine (5-HT)-induced (SPGN-mediated) plasma extravasation (PE) by 35%, and further decreases were obtained by perfusing larger concentrations of lidocaine. Intraarticular bupivacaine 0.025% inhibited 5-HT-induced PE by 60%, and a 95% inhibition was obtained with bupivacaine 0.05%. Larger local anesthetic concentrations were necessary to inhibit C fiber-mediated PE than those required to inhibit SPGN-mediated PE. Lidocaine 0.4% was required to reduce mustard oil-induced PE by 60%. Lidocaine 2% inhibited mustard oil-induced PE to baseline levels. Bupivacaine 0.1% was required for an 80% reduction of PE. Bupivacaine 0.25% inhibited mustard oil-induced PE to baseline levels. Our results demonstrate differential effects of local anesthetics on SPGN- and C fiber-mediated PE but confirm the concept of using smaller concentrations of local anesthetics to achieve inhibition of postoperative inflammation. Local anesthetic wound irrigation is often used to treat postoperative surgical pain. Large concentrations of local anesthetics are usually used, and these concentrations may have possible neurotoxic and myotoxic effects. Our results demonstrate antiinflammatory effects of lidocaine and bupivacaine at concentrations smaller than

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

PubMed

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.

Mechanistic Insights into Neurotoxicity Induced by Anesthetics in the Developing Brain

PubMed Central

Lei, Xi; Guo, Qihao; Zhang, Jun

2012-01-01

Compelling evidence has shown that exposure to anesthetics used in the clinic can cause neurodegeneration in the mammalian developing brain, but the basis of this is not clear. Neurotoxicity induced by exposure to anesthestics in early life involves neuroapoptosis and impairment of neurodevelopmental processes such as neurogenesis, synaptogenesis and immature glial development. These effects may subsequently contribute to behavior abnormalities in later life. In this paper, we reviewed the possible mechanisms of anesthetic-induced neurotoxicity based on new in vitro and in vivo findings. Also, we discussed ways to protect against anesthetic-induced neurotoxicity and their implications for exploring cellular and molecular mechanisms of neuroprotection. These findings help in improving our understanding of developmental neurotoxicology and in avoiding adverse neurological outcomes in anesthesia practice. PMID:22837663

A Comparison of Hamster Anesthetics and Their Effect on Mosquito Blood Feeding

USDA-ARS?s Scientific Manuscript database

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...

Modelling of noble anaesthetic gases and high hydrostatic pressure effects in lipid bilayers

DOE PAGES

Moskovitz, Yevgeny; Yang, Hui

2015-01-08

Our objective was to study molecular processes that might be responsible for inert gas narcosis and high-pressure nervous syndrome. The classical molecular dynamics trajectories (200 ns-long) of dioleoylphosphatidylcholine (DOPC) bilayers simulated by the Berger force field were evaluated for water and the atomic distribution of noble gases around DOPC molecules at a pressure range of 1 - 1000 bar and temperature of 310 Kelvin. Xenon and argon have been tested as model gases for general anesthetics, and neon has been investigated for distortions that are potentially responsible for neurological tremor at hyperbaric conditions. The analysis of stacked radial pair distributionmore » functions of DOPC headgroup atoms revealed the explicit solvation potential of gas molecules, which correlates with their dimensions. The orientational dynamics of water molecules at the biomolecular interface should be considered as an influential factor; while excessive solvation effects appearing in the lumen of membrane-embedded ion channels could be a possible cause of inert gas narcosis. All the noble gases tested exhibit similar patterns of the order parameter for both DOPC acyl chains, which is opposite to the patterns found for the order parameter curve at high hydrostatic pressures in intact bilayers. This finding supports the ‘critical volume’ hypothesis of anesthesia pressure reversal. The irregular lipid headgroup-water boundary observed in DOPC bilayers saturated with neon in the pressure range of 1 - 100 bar could be associated with the possible manifestation of neurological tremor at the atomic scale. The non-immobilizer neon also demonstrated the highest momentum impact on the normal component of the DOPC diffusion coefficient representing monolayers undulations rate, which indicates enhanced diffusivity, rather than atom size, as the key factor.« less

EDITORIAL: Cold Quantum GasesEditorial: Cold Quantum Gases

NASA Astrophysics Data System (ADS)

Vassen, W.; Hemmerich, A.; Arimondo, E.

2003-04-01

This Special Issue of Journal of Optics B: Quantum and Semiclassical Optics brings together the contributions of various researchers working on theoretical and experimental aspects of cold quantum gases. Different aspects of atom optics, matter wave interferometry, laser manipulation of atoms and molecules, and production of very cold and degenerate gases are presented. The variety of subjects demonstrates the steadily expanding role associated with this research area. The topics discussed in this issue, extending from basic physics to applications of atom optics and of cold atomic samples, include: bulletBose--Einstein condensation bulletFermi degenerate gases bulletCharacterization and manipulation of quantum gases bulletCoherent and nonlinear cold matter wave optics bulletNew schemes for laser cooling bulletCoherent cold molecular gases bulletUltra-precise atomic clocks bulletApplications of cold quantum gases to metrology and spectroscopy bulletApplications of cold quantum gases to quantum computing bulletNanoprobes and nanolithography. This special issue is published in connection with the 7th International Workshop on Atom Optics and Interferometry, held in Lunteren, The Netherlands, from 28 September to 2 October 2002. This was the last in a series of Workshops organized with the support of the European Community that have greatly contributed to progress in this area. The scientific part of the Workshop was managed by A Hemmerich, W Hogervorst, W Vassen and J T M Walraven, with input from members of the International Programme Committee who are listed below. The practical aspects of the organization were ably handled by Petra de Gijsel from the Vrije Universiteit in Amsterdam. The Workshop was funded by the European Science Foundation (programme BEC2000+), the European Networks 'Cold Quantum Gases (CQG)', coordinated by E Arimondo, and 'Cold Atoms and Ultraprecise Atomic Clocks (CAUAC)', coordinated by J Henningsen, by the German Physical Society (DFG), by

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

PubMed

Liu, Jin; Hu, Zhao-yang; Ye, Qi-quan; Dai, Shuo-hua

2009-03-05

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. Median effective doses (ED(50)) 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 (S(1)). So did median ones of percentile 48 - 52 for breeding median offspring (M(1)), resistant ones of percentile 91 - 95 for breeding resistant offspring (R(1)). Process was repeated through 31 generations, in the 37th generation, S(37), M(37) and R(37) were used to determine ED(50) for enflurane, isoflurane, sevoflurane, desflurane, halothane, methoxyflurane, chloroform and trichloroethylene, then ED(50) values were correlated with minimum alveolar concentration (MAC) values in human. 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, ED(50) values in three strains correlated directly with MAC values in human. Three Drosophila melanogaster strains with high, median and low sensitivity to volatile anesthetics, but with same hereditary background were developed. The ED(50) are directly correlated with MAC in human for eight volatile anesthetics.

Effects of Topical Anesthetics on Pullularia pullulans and Debaryomyces hansenii

PubMed Central

Merdinger, Emanuel; Guthmann, Walter S.; Mangine, Francis W.

1969-01-01

The inhibitory effects of three topical anesthetics of various concentrations on the growth of Pullularia pullulans, Debaryomyces hansenii, and on pigment production by P. pullulans were investigated. The topical anesthetics were benoxinate hydrochloride, proparacaine hydrochloride, and tetracaine hydrochloride. In decreasing order, the inhibiting effects of the drugs on growth were benoxinate, tetracaine, and proparacaine for P. pullulans, and tetracaine, benoxinate, and proparacaine for D. hansenii. The pigment formation in P. pullulans was inhibited by the three drugs. PMID:5392897

Effects of topical anesthetics on Pullalaria pullulans and Debaryomyces hansenii.

PubMed

Merdinger, E; Guthmann, W S; Mangine, F W

1969-09-01

The inhibitory effects of three topical anesthetics of various concentrations on the growth of Pullularia pullulans, Debaryomyces hansenii, and on pigment production by P. pullulans were investigated. The topical anesthetics were benoxinate hydrochloride, proparacaine hydrochloride, and tetracaine hydrochloride. In decreasing order, the inhibiting effects of the drugs on growth were benoxinate, tetracaine, and proparacaine for P. pullulans, and tetracaine, benoxinate, and proparacaine for D. hansenii. The pigment formation in P. pullulans was inhibited by the three drugs.

An analysis of the effectiveness of two topical anesthetics.

PubMed Central

Rosivack, R. G.; Koenigsberg, S. R.; Maxwell, K. C.

1990-01-01

This study compared the effectiveness of topical benzocaine 20%, lidocaine 5%, and a placebo in reducing the pain caused by needle insertion when the medicament was placed in the mucobuccal fold above the maxillary canine eminence. Both topical anesthetics and the placebo were randomly tested against each other bilaterally. For uniformity the agents were left in place for three minutes before needle insertion. A 27 gauge short needle mounted on an aspirating syringe was then inserted just past the bevel. Each subject rated the degree of pain on a visual analogue scale 100 mm in length. A pulse oximeter was used to record the heart rate. The results indicate that both topical anesthetics are significantly better than the placebo in reducing pain caused by needle insertion, although no statistically significant differences were found between the two topical anesthetics. Statistically significant differences in heart rate were seen, but these differences were not clinically significant. It is concluded that benzocaine 20% and lidocaine 5% significantly reduce the pain during needle insertion. PMID:2097909

Membrane permeable local anesthetics modulate NaV1.5 mechanosensitivity

PubMed Central

Beyder, Arthur; Strege, Peter R.; Bernard, Cheryl; Farrugia, Gianrico

2012-01-01

Voltage-gated sodium selective ion channel NaV1.5 is expressed in the heart and the gastrointestinal tract, which are mechanically active organs. NaV1.5 is mechanosensitive at stimuli that gate other mechanosensitive ion channels. Local anesthetic and antiarrhythmic drugs act upon NaV1.5 to modulate activity by multiple mechanisms. This study examined whether NaV1.5 mechanosensitivity is modulated by local anesthetics. NaV1.5 channels wereexpressed in HEK-293 cells, and mechanosensitivity was tested in cell-attached and excised inside-out configurations. Using a novel protocol with paired voltage ladders and short pressure pulses, negative patch pressure (-30 mmHg) in both configurations produced a hyperpolarizing shift in the half-point of the voltage-dependence of activation (V1/2a) and inactivation (V1/2i) by about -10 mV. Lidocaine (50 µM) inhibited the pressure-induced shift of V1/2a but not V1/2i. Lidocaine inhibited the tonic increase in pressure-induced peak current in a use-dependence protocol, but it did not otherwise affect use-dependent block. The local anesthetic benzocaine, which does not show use-dependent block, also effectively blocked a pressure-induced shift in V1/2a. Lidocaine inhibited mechanosensitivity in NaV1.5 at the local anesthetic binding site mutated (F1760A). However, a membrane impermeable lidocaine analog QX-314 did not affect mechanosensitivity of F1760A NaV1.5 when applied from either side of the membrane. These data suggest that the mechanism of lidocaine inhibition of the pressure-induced shift in the half-point of voltage-dependence of activation is separate from the mechanisms of use-dependent block. Modulation of NaV1.5 mechanosensitivity by the membrane permeable local anesthetics may require hydrophobic access and may involve membrane-protein interactions. PMID:22874086

The anesthetic action of some polyhalogenated ethers-Monte Carlo method based QSAR study.

PubMed

Golubović, Mlađan; Lazarević, Milan; Zlatanović, Dragan; Krtinić, Dane; Stoičkov, Viktor; Mladenović, Bojan; Milić, Dragan J; Sokolović, Dušan; Veselinović, Aleksandar M

2018-04-13

Up to this date, there has been an ongoing debate about the mode of action of general anesthetics, which have postulated many biological sites as targets for their action. However, postoperative nausea and vomiting are common problems in which inhalational agents may have a role in their development. When a mode of action is unknown, QSAR modelling is essential in drug development. To investigate the aspects of their anesthetic, QSAR models based on the Monte Carlo method were developed for a set of polyhalogenated ethers. Until now, their anesthetic action has not been completely defined, although some hypotheses have been suggested. Therefore, a QSAR model should be developed on molecular fragments that contribute to anesthetic action. QSAR models were built on the basis of optimal molecular descriptors based on the SMILES notation and local graph invariants, whereas the Monte Carlo optimization method with three random splits into the training and test set was applied for model development. Different methods, including novel Index of ideality correlation, were applied for the determination of the robustness of the model and its predictive potential. The Monte Carlo optimization process was capable of being an efficient in silico tool for building up a robust model of good statistical quality. Molecular fragments which have both positive and negative influence on anesthetic action were determined. The presented study can be useful in the search for novel anesthetics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Volatile anesthetics compete for common binding sites on bovine serum albumin: a 19F-NMR study.

PubMed Central

Dubois, B W; Cherian, S F; Evers, A S

1993-01-01

There is controversy as to the molecular nature of volatile anesthetic target sites. One proposal is that volatile anesthetics bind directly to hydrophobic binding sites on certain sensitive target proteins. Consistent with this hypothesis, we have previously shown that a fluorinated volatile anesthetic, isoflurane, binds saturably [Kd (dissociation constant) = 1.4 +/- 0.2 mM, Bmax = 4.2 +/- 0.3 sites] to fatty acid-displaceable domains on serum albumin. In the current study, we used 19F-NMR T2 relaxation to examine whether other volatile anesthetics bind to the same sites on albumin and, if so, whether they vary in their affinity for these sites. We show that three other fluorinated volatile anesthetics bind with varying affinity to fatty acid-displaceable domains on serum albumin: halothane, Kd = 1.3 +/- 0.2 mM; methoxyflurane, Kd = 2.6 +/- 0.3 mM; and sevoflurane, Kd = 4.5 +/- 0.6 mM. These three anesthetics inhibit isoflurane binding in a competitive manner: halothane, K(i) (inhibition constant) = 1.3 +/- 0.2 mM; methoxyflurane, K(i) = 2.5 +/- 0.4 mM; and sevoflurane, K(i) = 5.4 +/- 0.7 mM--similar to each anesthetic's respective Kd of binding to fatty acid displaceable sites. These results illustrate that a variety of volatile anesthetics can compete for binding to specific sites on a protein. PMID:8341659

The clinical course of anesthetic induction in lung transplant recipients with pulmonary complications after hematopoietic stem cell transplantation.

PubMed

Mizota, Toshiyuki; Matsukawa, Shino; Fukagawa, Hiroshi; Daijo, Hiroki; Tanaka, Tomoharu; Chen, Fengshi; Date, Hiroshi; Fukuda, Kazuhiko

2015-08-01

We examined the clinical course of anesthetic induction in lung transplant recipients with pulmonary complications after hematopoietic stem cell transplantation (post-HSCT), focusing on ventilatory management. We aimed to determine the incidence of oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction in post-HSCT lung transplant recipients, and to explore factors associated with their development. Nineteen consecutive patients who underwent lung transplantation post-HSCT at Kyoto University Hospital (Japan) were retrospectively studied. Data regarding patient characteristics, preoperative examination, and clinical course during anesthetic induction were analyzed. The incidence of oxygen desaturation (SpO2 < 90 %) during anesthetic induction and severe respiratory acidosis (pH < 7.2) after anesthetic induction were 21.1 and 26.3 %, respectively. Reduced dynamic compliance (Cdyn) during mechanical ventilation was significantly associated with oxygen desaturation during anesthetic induction (p = 0.01), as well as severe respiratory acidosis after anesthetic induction (p = 0.01). The preoperative partial pressure of carbon dioxide in arterial blood (PaCO2; r = -0.743, p = 0.002) and body mass index (BMI; r = 0.61, p = 0.021) significantly correlated with Cdyn, and multivariate analysis revealed that both PaCO2 and BMI were independently associated with Cdyn. Oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction frequently occur in post-HSCT lung transplant recipients. Low Cdyn may, at least partially, explain oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction. Moreover, preoperative hypercapnia and low BMI were predictive of low Cdyn.

General Anesthetics Have Additive Actions on Three Ligand-Gated Ion Channels

PubMed Central

Jenkins, Andrew; Lobo, Ingrid A.; Gong, Diane; Trudell, James R.; Solt, Ken; Harris, R. Adron; Eger, Edmond I

2008-01-01

Background The purpose of this study was to determine whether pairs of compounds, including general anesthetics, could simultaneously modulate receptor function in a synergistic manner, thus demonstrating the existence of multiple intra-protein anesthetic binding sites. Methods Using standard electrophysiologic methods, we measured the effects of at least one combination of benzene, isoflurane, halothane, chloroform, flunitrazepam, zinc and pentobarbital on at least one of the following ligand gated ion channels: N-methyl-D-aspartate receptors (NMDARs), glycine receptors (GlyRs) and γ-aminobutyric acid type A receptors (GABAARs). Results All drug-drug-receptor combinations were found to exhibit additive, not synergistic modulation. Isoflurane with benzene additively depressed NMDAR function. Isoflurane with halothane additively enhanced GlyR function, as did isoflurane with zinc. Isoflurane with halothane additively enhanced GABAAR function as did all of the following: halothane with chloroform, pentobarbital with isoflurane, and flunitrazepam with isoflurane. Conclusions The simultaneous allosteric modulation of ligand gated ion channels by general anesthetics is entirely additive. Where pairs of general anesthetic drugs interact synergistically to produce general anesthesia, they must do so on systems more complex than a single receptor. PMID:18633027

Influence of inhalation anesthetics on ion transport across a planar bilayer lipid membrane.

PubMed

Hichiri, Kei; Shirai, Osamu; Kano, Kenji

2012-01-01

Ion transport from one aqueous phase (W1) to another (W2) across a planar bilayer lipid membrane (BLM) in the presence of inhalation anesthetics was electrochemically investigated. In the absence of inhalation anesthetics in the BLM system, no ion transport current flowed between W1 and W2 across the BLM. When inhalation anesthetics such as halothane, chloroform, diethyl ether and trichloroethylene were added to the two aqueous phases or the BLM, the ion transport current quite clearly appeared. When the ratio of the concentration of KCl or NaCl in W1 to that in W2 was varied, the zero current potential across the BLM was shifted. By considering the magnitude of the potential shift, we concluded that the ion transport current can be predominantly ascribed to the transport of Cl(-) across the BLM. Since the dielectric constants of these anesthetics are larger than that of the inner hydrophobic domain of the BLM, the concentration of hydrophilic electrolyte ions in the BLM increases with the increase in the dielectric constant of the inner hydrophobic domain caused by addition of these anesthetics. These situations lead to an increase in the ion permeability coefficient.

The effects of xenon and nitrous oxide gases on alcohol relapse.

PubMed

Vengeliene, Valentina; Bessiere, Baptiste; Pype, Jan; Spanagel, Rainer

2014-02-01

In recent years, the glutamate theory of alcoholism has emerged as a major theory in the addiction research field and N-methyl-d-aspartate (NMDA) receptors have been shown to play a major role in alcohol craving and relapse. The NMDA receptors are considered as the primary side of action of the anesthetic gases xenon (Xe) and nitrous oxide (N2 O). Despite the rapid on/off kinetics of these gases on the NMDA receptor, a brief gas exposure can induce an analgesic or antireward effect lasting several days. The aim of this study was to examine the effect of both Xe and N2 O on alcohol-seeking and relapse-like drinking behavior (measured as the alcohol deprivation effect) in Wistar rats. We used 2 standard procedures-the alcohol deprivation model with repeated deprivation phases and the cue-induced reinstatement model of alcohol seeking-to study the effect of 2 brief gas exposures of either Xe, N2 O, or control gas on relapse-like drinking and alcohol-seeking behavior. Here, we show that exposure to Xe during the last 24 hours of abstinence produced a trend toward reduced ethanol intake during the first alcohol re-exposure days. In addition, Xe gas exposure significantly decreased the cue-induced reinstatement of alcohol-seeking behavior. N2 O had no effect on either behavior. Xe reduces alcohol-seeking behavior in rats and may therefore also interfere with craving in human alcoholics. Copyright © 2013 by the Research Society on Alcoholism.

Effect of certain anesthetic agents on mallard ducks

USGS Publications Warehouse

Cline, D.R.; Greenwood, R.J.

1972-01-01

Four anesthetic agents used in human or veterinary medicine and 3 experimental anesthetic preparations were evaluated for effectiveness in inducing narcosis when administered orally to game-farm mallard ducks (Anas platyrhynchos).Tribromoethanol was the only compound to satisfy criteria of initial tests. Mean duration of the induction, immobilization, and recovery periods was 2.4 minutes, 8.7 minutes, and 1.3 hours, respectively, at the median effective dosage for immobilization (ED50; 100 mg./kg. of body weight). The median lethal dosage (LD50) was 400 mg./kg. of body weight.Tribromoethanol was also tested on mallards during the reproductive season. Effects on the hatchability of eggs or the survival of young were not detected.

[An experimental study of the computer-controlled equipment for delivering volatile anesthetic agent].

PubMed

Sun, B; Li, W Z; Yue, Y; Jiang, C W; Xiao, L Y

2001-11-01

Our newly-designed computer-controlled equipment for delivering volatile anesthetic agent uses the subminiature singlechip processor as the central controlling unit. The variables, such as anesthesia method, anesthetic agent, the volume of respiratory loop, age of patient, sex, height, weight, environment temperature and the grade of ASA are all input from the keyboard. The anesthetic dosage, calculated by the singlechip processor, is converted into the signals controlling the pump to accurately deliver anesthetic agent into respiratory loop. We have designed an electrocircuit for the equipment to detect the status of the pump's operation, so we can assure of the safety and the stability of the equipment. The output precision of the equipment, with a good anti-jamming capability, is 1-2% for high flow anesthesia and 1-5% for closed-circuit anesthesia and its self-detecting working is reliable.

A literature review on anesthetic practice for carotid endarterectomy surgery based on cost, hemodynamic stability, and neurologic status.

PubMed

Meitzner, Mark C; Skurnowicz, Julie A; Mitchell, Anne

2007-06-01

An extensive literature review was undertaken to evaluate the best anesthetic practice for carotid endarterectomy surgery. Two anesthetic techniques were evaluated: general anesthetic with an endotracheal tube and regional anesthetic block. Three variables were reviewed with respect to significant clinical outcomes based on anesthetic technique. Relevant literature was obtained through multiple sources that included professional journals, a professional website, and textbooks. According to the literature, there is an advantage to performing regional anesthesia with respect to cost and neurologic status. Information analyzed was inconclusive with respect to hemodynamic stability and anesthetic technique. We conclude that regional anesthesia may have some slight advantages; however, more investigation is warranted.

Apparatus for waste collection and storage

NASA Technical Reports Server (NTRS)

Thornton, Jr., William E. (Inventor); Whitmore, Henry B. (Inventor)

1989-01-01

An apparatus for collection of fecal matter designed to operate efficiently in a zero gravity environment. The system comprises a waste collection area within a body having a seat opening. Low pressure within the waste collection area directs fecal matter away from the user's buttocks and prevents the escape of undesirable gases. The user actuates a piston covered with an absorbent pad that sweeps through the waste collection area to collect fecal matter, scrub the waste collector area, press the waste against an end of the waste collection area and retracts, leaving the used pad. Multiple pads are provided on the piston to accommodate multiple uses of the system. Also a valve allows air to be drawn through the body, which valve will not be plugged with fecal matter. A sheet feeder feeds fresh sheets of absorbent pad to a face of the piston with each actuation.

Predictive accuracy of a model of volatile anesthetic uptake.

PubMed

Kennedy, R Ross; French, Richard A; Spencer, Christopher

2002-12-01

A computer program that models anesthetic uptake and distribution has been in use in our department for 20 yr as a teaching tool. New anesthesia machines that electronically measure fresh gas flow rates and vaporizer settings allowed us to assess the performance of this model during clinical anesthesia. Gas flow, vaporizer settings, and end-tidal concentrations were collected from the anesthesia machine (Datex S/5 ADU) at 10-s intervals during 30 elective anesthetics. These were entered into the uptake model. Expired anesthetic vapor concentrations were calculated and compared with actual values as measured by the patient monitor (Datex AS/3). Sevoflurane was used in 16 patients and isoflurane in 14 patients. For all patients, the median performance error was -0.24%, the median absolute performance error was 13.7%, divergence was 2.3%/h, and wobble was 3.1%. There was no significant difference between sevoflurane and isoflurane. This model predicted expired concentrations well in these patients. These results are similar to those seen when comparing calculated and actual propofol concentrations in propofol infusion systems and meet published guidelines for the accuracy of models used in target-controlled anesthesia systems. This model may be useful for predicting responses to changes in fresh gas and vapor settings. We compared measured inhaled anesthetic concentrations with those predicted by a model. The method used for comparison has been used to study models of propofol administration. Our model predicts expired isoflurane and sevoflurane concentrations at least as well as common propofol models predict arterial propofol concentrations.

Anesthetic activity of plant essential oils on Cyprinus carpio (koi carp).

PubMed

Khumpirapang, Nattakanwadee; Pikulkaew, Surachai; Anuchapreeda, Songyot; Okonogi, Siriporn

2018-03-19

The aims of this study were to investigate the anesthetic and cytotoxic effects of essential oils (EOs) of Ocimum basilicum (OBO), O. canum (OCO), and O. sanctum (OSO) on Cyprinus carpio (koi carp). For anesthetic effect, induction time to surgical anesthesia and recovery time were determined. For cytotoxicity effect, viability of fish peripheral blood nuclear cells (PBMCs) was investigated. Results indicated that increasing oil concentration caused significant (p < 0.01) decrease of induction time. OSO at 100, 200, and 300 mg/L gave the induction time of 169.5 ± 10.2, 62.8 ± 2.3, 45.3 ± 2.2 sec, respectively, significantly shorter than OCO, and OBO. The recovery time of anesthetized fish was dose dependent (p <0.01). Among them, OCO showed the longest recovery time of 313.0 ± 8.1, 420.7 ± 12.6, 616.6 ± 12.1 sec for concentrations of 100, 200, and 300 mg/L, respectively, followed by OSO and OBO, respectively. Within 10 min contact time of the EOs and fish PBMCs, the fish PBMC viability was higher than 80%. Increase contact time and EO concentration caused an increase in cytotoxicity to fish PBMC. OBO showed less toxic than OSO and OCO. Based on the desired induction and recovery times for anesthetizing koi carp, OBO, OCO, and OSO at 300, 200, and 100 mg/L, respectively were suggested to be the most suitable. It was concluded that OBO, OCO, and OSO can be used as natural anesthetics for fish.

High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study.

PubMed

Biganzoli, Laura; Racanella, Gaia; Marras, Roberto; Rigamonti, Lucia

2015-01-01

The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO2 emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in Biganzoli et al. (2014) and from the dolomitic sorbent production plant. The results of the LCA show minor changes in the potential impacts between the two operational modes of the plants. These differences are for 8 impact categories in favour of the new operational mode based on the addition of the dolomitic sorbent, and for 7 impact categories in favour of the traditional operation. A final evaluation was conducted on the potential

Supercritical waste oxidation of aqueous wastes

NASA Technical Reports Server (NTRS)

Modell, M.

1986-01-01

For aqueous wastes containing 1 to 20 wt% organics, supercritical water oxidation is less costly than controlled incineration or activated carbon treatment and far more efficient than wet oxidation. Above the critical temperature (374 C) and pressure (218 atm) of water, organic materials and gases are completely miscible with water. In supercritical water oxidation, organics, air and water are brought together in a mixture at 250 atm and temperatures above 400 C. Organic oxidation is initiated spontaneously at these conditions. The heat of combustion is released within the fluid and results in a rise in temperature 600 to 650 C. Under these conditions, organics are destroyed rapidly with efficiencies in excess of 99.999%. Heteroatoms are oxidized to acids, which can be precipitated out as salts by adding a base to the feed. Examples are given for process configurations to treat aqueous wastes with 10 and 2 wt% organics.

Anesthetic-resistant spontaneous mutant of Drosophila melanogaster: intensified response to /sup 60/Cobalt radiation damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamo, S.; Nakashima-Tanaka, E.; Megumi, T.

1985-02-25

Accumulating evidence suggests that the extent of acute damage by ionizing irradiation is closely related to the state of membrane orderliness. Decreased orderliness apparently protects organisms from ionizing irradiation. Because anesthetics decrease membrane orderliness, anesthesia is expected to affect damages caused by ionizing irradiation. The present study compared the effects of /sup 60/Co irradiation on Drosophila melanogaster between an anesthetic-resistant spontaneous mutant and an anesthetic-sensitive strain. An anesthetic-resistant mutant strain, Eth-29, of Drosophila melanogaster has previously been established. Eth-29 is resistant to diethyl-ether, chloroform and halothane. The anesthetic-resistant strain was found to be radiosensitive when evaluated by survival at themore » eighth day after irradiation or by dyskinesia (knock-down) at the second day. The results indicate that anesthetic resistance may be related to an increase in orderliness. The findings in reciprocal crosses between Eth-29 and the control strain indicate that the mechanism of survival is different from that of knock-down. Presumably, knock-down is the direct sequela of irradiation, and the present result suggests that membrane damage may be involved in inducing knock-down. 18 references, 3 figures.« less

Common Anesthetic-binding Site for Inhibition of Pentameric Ligand-gated Ion Channels.

PubMed

Kinde, Monica N; Bu, Weiming; Chen, Qiang; Xu, Yan; Eckenhoff, Roderic G; Tang, Pei

2016-03-01

Identifying functionally relevant anesthetic-binding sites in pentameric ligand-gated ion channels (pLGICs) is an important step toward understanding the molecular mechanisms underlying anesthetic action. The anesthetic propofol is known to inhibit cation-conducting pLGICs, including a prokaryotic pLGIC from Erwinia chrysanthemi (ELIC), but the sites responsible for functional inhibition remain undetermined. We photolabeled ELIC with a light-activated derivative of propofol (AziPm) and performed fluorine-19 nuclear magnetic resonance experiments to support propofol binding to a transmembrane domain (TMD) intrasubunit pocket. To differentiate sites responsible for propofol inhibition from those that are functionally irrelevant, we made an ELIC-γ-aminobutyric acid receptor (GABAAR) chimera that replaced the ELIC-TMD with the α1β3GABAAR-TMD and compared functional responses of ELIC-GABAAR and ELIC with propofol modulations. Photolabeling showed multiple AziPm-binding sites in the extracellular domain (ECD) but only one site in the TMD with labeled residues M265 and F308 in the resting state of ELIC. Notably, this TMD site is an intrasubunit pocket that overlaps with binding sites for anesthetics, including propofol, found previously in other pLGICs. Fluorine-19 nuclear magnetic resonance experiments supported propofol binding to this TMD intrasubunit pocket only in the absence of agonist. Functional measurements of ELIC-GABAAR showed propofol potentiation of the agonist-elicited current instead of inhibition observed on ELIC. The distinctly different responses of ELIC and ELIC-GABAAR to propofol support the functional relevance of propofol binding to the TMD. Combining the newly identified TMD intrasubunit pocket in ELIC with equivalent TMD anesthetic sites found previously in other cationic pLGICs, we propose this TMD pocket as a common site for anesthetic inhibition of pLGICs.

Changes in Publication-Based Academic Interest in Local Anesthetics Over the Past 50 Years.

PubMed

Vlassakov, Kamen V; Kissin, Igor

2016-07-01

To present the history of changes in academic interest in local anesthetics quantitatively. The changes in publication-based academic interest in local anesthetics were assessed using information from the database of PubMed. The assessment was mostly based on the following indices: general popularity index (GPI), representing the proportion of articles on a drug relative to all articles in the field of regional anesthesia, and specific popularity index (SPI), representing the proportion of articles on a drug relative to all articles in one of the four forms of regional anesthesia: local anesthesia, spinal anesthesia, epidural anesthesia, and peripheral nerve blocks. The most important general feature of the changes in publication-based academic interest in local anesthetics for the past 50 years was the concentration of this interest on a very limited number of drugs. By 2010-2014, only three anesthetics demonstrated the GPI value above 4.0: bupivacaine (10.1), lidocaine (10.0), and ropivacaine (4.6). All other local anesthetics had GPI declining mostly to less than 1.0 (2010-2014). The rate of change in publication-based academic interest was very slow in both its increase and decline. The most profound change in publication-based academic interests was caused by the introduction of bupivacaine. During a 20-year period (from 1965-1969 to 1985-1989), bupivacaine's GPI increased from 1.3 to 12.9. A slowly developing concentration of publication-based academic interest on a very limited number of local anesthetics was the dominant feature related to this class of anesthetic agents. Copyright © 2016 Anesthesia History Association. Published by Elsevier Inc. All rights reserved.

Effect of toxic threat nerve agents on anesthetic requirements of representative pr-anesthetic medicants and inhalant and parenteral general anesthetic in the cat. Annual report, 15 July 1985-14 July 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, A.I.

1986-07-30

The effect of soman on anesthetic requirements of halothane and isoflurane was studied before and after administration of acepromazine maleate (0.2 mg/kg). Insufficient data has been obtained to date to draw conclusions on any possible drug interactions.

The effect of low concentrations versus high concentrations of local anesthetics for labour analgesia on obstetric and anesthetic outcomes: a meta-analysis.

PubMed

Sultan, Pervez; Murphy, Caitriona; Halpern, Stephen; Carvalho, Brendan

2013-09-01

The influence that different concentrations of labour epidural local anesthetic have on assisted vaginal delivery (AVD) and many obstetric outcomes and side effects is uncertain. The purpose of this meta-analysis was to determine whether local anesthetics utilized at low concentrations (LCs) during labour are associated with a decreased incidence of AVD when compared with high concentrations (HCs). We searched PubMed, Ovid EMBASE, Ovid MEDLINE, CINAHL, Scopus, clinicaltrials.gov, and Cochrane databases for randomized controlled trials of labouring patients that compared LCs (defined as ≤ 0.1% epidural bupivacaine or ≤ 0.17% ropivacaine) of epidural local anesthetic with HCs for maintenance of analgesia. The primary outcome was AVD and secondary outcomes included Cesarean delivery, duration of labour, analgesia, side effects (nausea and vomiting, motor block, hypotension, pruritus, and urinary retention), and neonatal outcomes. The odds ratios (OR) or weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated using random effects modelling. An OR < 1 or a WMD < 0 favoured LCs. Eleven studies met our criteria (eight bupivacaine and three ropivacaine studies), providing 1,145 patients in the LCs group and 852 patients in the HCs group for analysis of the primary outcome. Low concentrations were associated with a reduction in the incidence of AVD (OR = 0.70; 95% CI 0.56 to 0.86; P < 0.001). There was no difference in the incidence of Cesarean delivery (OR 1.05; 95% CI 0.82 to 1.33; P = 0.7). The LCs group had less motor block (OR 3.9; 95% CI 1.59 to 9.55; P = 0.003), greater ambulation (OR 2.8; 95% CI 1.1 to 7.14; P = 0.03), less urinary retention (OR 0.42; 95% CI 0.23 to 0.73; P = 0.002), and a shorter second stage of labour (WMD -14.03; 95% CI -27.52 to -0.55; P = 0.04) compared with the HCs group. There were no differences between groups in pain scores, maternal nausea and vomiting, hypotension, fetal heart rate abnormalities, five

78 FR 29142 - Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0001] Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Anesthetic and Analgesic Drug Products Advisory Committee. General Function of the Committee: To provide...

77 FR 67380 - Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001] Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Anesthetic and Analgesic Drug Products Advisory Committee. General Function of the Committee: To provide...

76 FR 78283 - Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0002] Anesthetic and Analgesic Drug Products Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Anesthetic and Analgesic Drug Products Advisory Committee. General Function of the Committee: To provide...

Apparatus for incinerating hazardous waste

DOEpatents

Chang, Robert C. W.

1994-01-01

An apparatus for incinerating wastes, including an incinerator having a combustion chamber, a fluidtight shell enclosing the combustion chamber, an afterburner, an off-gas particulate removal system and an emergency off-gas cooling system. The region between the inner surface of the shell and the outer surface of the combustion chamber forms a cavity. Air is supplied to the cavity and heated as it passes over the outer surface of the combustion chamber. Heated air is drawn from the cavity and mixed with fuel for input into the combustion chamber. The pressure in the cavity is maintained at least approximately 2.5 cm WC (about 1" WC) higher than the pressure in the combustion chamber. Gases cannot leak from the combustion chamber since the pressure outside the chamber (inside the cavity) is higher than the pressure inside the chamber. The apparatus can be used to treat any combustible wastes, including biological wastes, toxic materials, low level radioactive wastes, and mixed hazardous and low level transuranic wastes.

Health-hazard evaluation report HETA 87-063-1808, Presbyterian Day Surgery Center, Albuquerque, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniels, W.J.; Gunter, B.

1987-07-01

In response to a request from employees to evaluate exposures to waste anesthetic gases and vapors at the Presbyterian Day Surgery Unit, located in Albuquerque, New Mexico, personal and area air-sampling and leak-detection testing was carried out for nitrous oxide (N/sub 2/O) and halogenated anesthetic agents in the six operating rooms at the facility. Nitrous oxide concentrations ranged from not detectable to 95 parts per million (ppm) with a mean of 20ppm. Five of the samples exceeded the NIOSH limit of 25ppm for N/sub 2/O during anesthetic administration. Ethrane levels in 14 personal and area air samples ranged from lessmore » than the limit of detection to 3.63ppm with a mean of 0.31ppm. Isoflurane and halothane were below the limits of detection. The ventilation system in use changed the air in excess of 20 times per hour. However, during a portion of surgical procedures the system was not operating, resulting in a higher than normal exposure level in three of the operating rooms.« less

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

PubMed

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.

Lipid Emulsion in Treatment of Local Anesthetic Toxicity.

PubMed

Collins, Shawn; Neubrander, Judy; Vorst, Zachary; Sheffield, Brad

2015-08-01

Epidural, spinal, regional, local, and intravenous administration of local anesthetics (LAs) is a cornerstone of anesthetic practice. LA toxicity is a grave consequence that is of great significance to anesthesia providers. Outcomes of LA toxicity range from inconvenient symptoms such as tinnitus, twitching, and hypotension to seizures; cardiovascular or respiratory collapse; and death. Lipid emulsion has emerged as a potential "magic bullet" in treating LA toxicity. This literature review provides background information and proposed mechanisms of action for LAs and lipid emulsion as well as animal experiments and a case report that speak to the effectiveness of lipid emulsion in the face of LA toxicity. Copyright © 2015 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

TREATMENT OF FISSION PRODUCT WASTE

DOEpatents

Huff, J.B.

1959-07-28

A pyrogenic method of separating nuclear reactor waste solutions containing aluminum and fission products as buring petroleum coke in an underground retort, collecting the easily volatile gases resulting as the first fraction, he uminum chloride as the second fraction, permitting the coke bed to cool and ll contain all the longest lived radioactive fission products in greatly reduced volume.

Improvement in likelihood to donate blood after being offered a topical anesthetic.

PubMed

Watanabe, Kyle M; Jay, Jeffrey; Alicto, Christopher; Yamamoto, Loren G

2011-02-01

While there are many reasons people choose not to donate blood, pain sustained during the venipuncture portion of the blood donation process is likely one deterrent to volunteer donation. The purpose of this study was to survey the improvement in likelihood of donation if participants were given the option of a topical anesthetic cream prior to venipuncture. Over a three month period 316 adults (convenience sample) completed a one page survey consisting of twelve questions pertaining to blood donation. Participants were asked about their likelihood of donating blood in the near future (No Possibility, Possible, Likely, Certain). They were then informed of the possibility of using a topical anesthetic cream prior to donation. Subsequently, their likelihood of donating blood was reassessed. Fifty (16%) subjects reported an increased likelihood of donating blood if offered a topical anesthetic (p〈0.0001). Of these respondents reporting an increase in donation likelihood, eleven improved by 2 or more likelihood categories. Amongst the 169 participants who never donated blood, 34 (20%) reported an increased likelihood of donation after being told about the topical anesthetic cream, compared to 16 (10%) of the 147 subjects who had previously donated blood (p=0.02). The findings of this study suggest that providing a topical anesthetic had a positive effect on the study participants' likelihood of donating blood. This improvement was greater amongst those who have never donated blood. Hawaii Medical Journal Copyright 2011.

Additives to local anesthetics for peripheral nerve blocks: Evidence, limitations, and recommendations.

PubMed

Bailard, Neil S; Ortiz, Jaime; Flores, Roland A

2014-03-01

The therapeutic rationale, clinical effectiveness, and potential adverse effects of medications used in combination with local anesthetics for peripheral nerve block therapy are reviewed. A wide range of agents have been tested as adjuncts to peripheral nerve blocks, which are commonly performed for regional anesthesia during or after hand or arm surgery, neck or spine surgery, and other procedures. Studies to determine the comparative merits of nerve block adjuncts are complicated by the wide variety of coadministered local anesthetics and sites of administration and by the heterogeneity of primary endpoints. Sodium bicarbonate has been shown to speed the onset of mepivacaine nerve blocks but delay the onset of others. Epinephrine has been shown to prolong sensory nerve blockade and delay systemic uptake of local anesthetics, thus reducing the risk of anesthetic toxicity. Tramadol, buprenorphine, dexamethasone, and clonidine appear to be effective additives in some situations. Midazolam, magnesium, dexmedetomidine, and ketamine cannot be routinely recommended as nerve block additives due to a dearth of supportive data, modest efficacy, and (in the case of ketamine) significant adverse effects. Recent studies suggest that administering additives intravenously or intramuscularly can provide many of the benefits of perineural administration while reducing the potential for neurotoxicity, contamination, and other hazards. Some additives to local anesthetics can hasten the onset of nerve block, prolong block duration, or reduce toxicity. On the other hand, poorly selected or unnecessary additives may not have the desired effect and may even expose patients to unnecessary risks.

Anesthetic management for Cesarean delivery in parturients with a diagnosis of dwarfism.

PubMed

Lange, Elizabeth M S; Toledo, Paloma; Stariha, Jillian; Nixon, Heather C

2016-08-01

The literature on the anesthetic management of parturients with dwarfism is sparse and limited to isolated case reports. Pregnancy complications associated with dwarfism include an increased risk of respiratory compromise, an increased risk of Cesarean delivery, and an unpredictable degree of anesthesia with neuraxial techniques. Therefore, we conducted this retrospective review to evaluate the anesthetic management of parturients with a diagnosis of dwarfism. We used a query of billing data to identify short statured women who underwent a Cesarean delivery during May 1, 2008 to May 1, 2013. We then hand searched the electronic medical record for qualifying patients with heights < 148 cm and a diagnosis of dwarfism. The extracted data included patient demographics and obstetric and anesthetic information. We identified 13 women with dwarfism who had 15 Cesarean deliveries in total. Twelve of the women had disproportionate dwarfism, and ten of the 15 Cesarean deliveries were due to cephalopelvic disproportion. Neuraxial anesthesia was attempted in 93% of deliveries. The dose chosen for initiation of neuraxial anesthesia was lower than the typical doses used in parturients of normal stature. Neuraxial anesthetic complications included difficult neuraxial placement (64%), high spinal (7%), inadequate surgical level (13%), and unrecognized intrathecal catheter (7%). The data collected suggest that females with a diagnosis of dwarfism may have difficult neuraxial placement and potentially require lower dosages of local anesthetic for both spinal and epidural anesthesia to achieve adequate surgical blockade.

Valve for waste collection and storage

NASA Technical Reports Server (NTRS)

Thornton, William E., Jr. (Inventor); Whitmore, Henry B. (Inventor)

1990-01-01

A method and valve apparatus for collection of fecal matter designed to operate efficiently in a zero gravity environment is presented. The system comprises a waste collection area within a body having a seat opening. Low pressure within the waste collection area directs fecal matter away from the user's buttocks and prevents the escape of undersirable gases. The user actuates a piston covered with an absorbent pad that sweeps through the waste collection area to collect the fecal matter, scrub the waste collection area, press the waste against an end of the waste collection area and retracts, leaving the used pad. Multiple pads are provided on the piston to accommodate multiple uses of the system. Also a valve allows air to be drawn through the body, so the valve will not be plugged with fecal matter. A sheet feeder feeds fresh sheets of absorbent pads to a face of the piston with each actuation.

Effect of different anesthetic agents on left ventricular systolic function assessed by echocardiography in hamsters.

PubMed

Tanaka, D M; Romano, M M D; Carvalho, E E V; Oliveira, L F L; Souza, H C D; Maciel, B C; Salgado, H C; Fazan-Júnior, R; Simões, M V

2016-08-25

Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected intramuscularly (K/X). LVEF obtained under the effect of anesthetics (ISO=62.2±3.1%, TP=66.2±2.7% and K/X=75.8±1.6%) was significantly lower than that obtained in conscious animals (87.5±1.7%, P<0.0001). The K/X combination elicited significantly higher LVEF values compared to ISO (P<0.001) and TP (P<0.05). K/X was associated with a lower dispersion of individual LVEF values compared to the other anesthetics. Under K/X, the left ventricular end diastolic diameter (LVdD) was increased (0.60±0.01 cm) compared to conscious animals (0.41±0.02 cm), ISO (0.51±0.02 cm), and TP (0.55±0.01 cm), P<0.0001. The heart rate observed with K/X was significantly lower than in the remaining conditions. These results indicate that the K/X combination may be the best anesthetic option for the in vivo assessment of cardiac systolic function in hamsters, being associated with a lower LVEF reduction compared to the other agents and showing values closer to those of conscious animals with a lower dispersion of results.

Effect of different anesthetic agents on left ventricular systolic function assessed by echocardiography in hamsters

PubMed Central

Tanaka, D.M.; Romano, M.M.D.; Carvalho, E.E.V.; Oliveira, L.F.L.; Souza, H.C.D.; Maciel, B.C.; Salgado, H.C.; Fazan-Júnior, R.; Simões, M.V.

2016-01-01

Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected intramuscularly (K/X). LVEF obtained under the effect of anesthetics (ISO=62.2±3.1%, TP=66.2±2.7% and K/X=75.8±1.6%) was significantly lower than that obtained in conscious animals (87.5±1.7%, P<0.0001). The K/X combination elicited significantly higher LVEF values compared to ISO (P<0.001) and TP (P<0.05). K/X was associated with a lower dispersion of individual LVEF values compared to the other anesthetics. Under K/X, the left ventricular end diastolic diameter (LVdD) was increased (0.60±0.01 cm) compared to conscious animals (0.41±0.02 cm), ISO (0.51±0.02 cm), and TP (0.55±0.01 cm), P<0.0001. The heart rate observed with K/X was significantly lower than in the remaining conditions. These results indicate that the K/X combination may be the best anesthetic option for the in vivo assessment of cardiac systolic function in hamsters, being associated with a lower LVEF reduction compared to the other agents and showing values closer to those of conscious animals with a lower dispersion of results. PMID:27580004

75 FR 81618 - Anesthetic and Life Support Drugs Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0001] Anesthetic and Life Support Drugs Advisory Committee; Notice of Meeting AGENCY: Food and Drug Administration...: Anesthetic and Life Support Drugs Advisory Committee. General Function of the Committee: To provide advice...

75 FR 39032 - Anesthetic and Life Support Drugs Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014